The combination therapy of magnetic hyperthermia and thermosensitive liposomes(TSL)is an emerging and effective cancer treatment method.The heat generation of magnetic nanoparticles(MNPs)due to an external alternating...The combination therapy of magnetic hyperthermia and thermosensitive liposomes(TSL)is an emerging and effective cancer treatment method.The heat generation of magnetic nanoparticles(MNPs)due to an external alternating magnetic field can not only directly damage tumor cells,but also serves as a triggering factor for the release of doxorubicin from TSL.The aim of this study is to investigate the effects in the degree of tumor cell damage of two proposed injection strategies that consider intravenous administration.Since both MNPs and TSL enter the tumor region intravenously,this study establishes a biological geometric model based on an experiment-based vascular distribution.Furthermore,this study derives the flow velocity of interstitial fluid after coupling the pressure distribution inside blood vessels and the pressure distribution of interstitial fluid,which then provides the convective velocity for the calculation of subsequent nanoparticle concentration.Different injection strategies for the proposed approach are evaluated by drug delivery result,temperature distribution,and tumor cell damage.Simulation results demonstrate that the proposed delayed injection strategy after optimization can not only result in a wider distribution for MNPs and TSL due to the sufficient diffusion time,but also improves the distribution of the temperature and drug concentration fields for the overall efficacy of combination therapy.展开更多
Air injection technique for developing shale oil has gained significant attention. However, the ability of the heat front to consistently propagate within the shale during air injection remains uncertain. To address t...Air injection technique for developing shale oil has gained significant attention. However, the ability of the heat front to consistently propagate within the shale during air injection remains uncertain. To address this, we investigated the heat front propagation within oil-detritus mixtures, shale cores, and fractured shale cores using a self-designed combustion tube(CT) and experimental schemes. By integrating the results obtained from high-pressure differential scanning calorimetry and CT, we developed a comprehensive reaction kinetics model to accurately analyze the main factors influencing the heat front propagation within fractured shale. The findings revealed that in the absence of additional fractures, the heat front failed to propagate within the tight shale. The flow of gases and liquids towards the shale core was impeded, resulting in the formation of a high-pressure zone at the front region of the shale. This pressure buildup significantly hindered air injection, leading to inadequate oxygen supply and the extinguishment of the heat front. However, the study demonstrated the stable propagation of the heat front within the oil-detritus mixtures, indicating the good combustion activity of the shale oil.Furthermore, the heat front successfully propagated within the fractured shale, generating a substantial amount of heat that facilitated the creation of fractures and enhanced gas injection and shale oil flow. It was important to note that after the heat front passed through the shale, the combustion intensity decreased. The simulation results indicated that injecting air into the main fracturing layers of the shale oil reservoir enabled the establishment of a stable heat front. Increasing the reservoir temperature(from 63 to 143℃) and oxygen concentration in the injected gas(from 11% to 21%) promoted notable heat front propagation and increased the average temperature of the heat front. It was concluded that temperature and oxygen concentration had the most important influence on the heat front propagation, followed by pressure and oil saturation.展开更多
Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs.NPs are typically...Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs.NPs are typically studied in controlled laboratory conditions,and their behavior in real-world,complex environments such as ultra-low permeability reservoirs,is not well understood due to the limited scope of their applications.This study investigates the efficacy and underlying mechanisms of NPs in decreasing injection pressure under various injection conditions(25—85℃,10—25 MPa).The results reveal that under optimal injection conditions,NPs effectively reduce injection pressure by a maximum of 22.77%in core experiment.The pressure reduction rate is found to be positively correlated with oil saturation and permeability,and negatively correlated with temperature and salinity.Furthermore,particle image velocimetry(PIV)experiments(25℃,atmospheric pressure)indicate that the pressure reduction is achieved by NPs through the reduction of wall shear resistance and wettability change.This work has important implications for the design of water injection strategies in ultra-low permeability reservoirs.展开更多
Based on the EAST equilibrium,the effects of boron(B)and neon(Ne)injected at different locations on the target heat load,and the distributions of B and Ne particles were investigated by transport code SOLPS-ITER.It wa...Based on the EAST equilibrium,the effects of boron(B)and neon(Ne)injected at different locations on the target heat load,and the distributions of B and Ne particles were investigated by transport code SOLPS-ITER.It was found that the B injection was more sensitive to the injection location for heat flux control than impurity Ne.The high electron and ion densities near the inner target in the discharge with impurity B injected from over X-point(R_(1))led to plasma detachment only at the inner target,and the localized B ions in the cases with injection from outer target location(R_(2))and upstream location(R_(3))led to far-SOL detachment at the outer target,but not at the inner target.In contrast,for Ne,the spatial distributions of Ne ions and electrons were found to be similar in all the cases at the three injection locations,and the detached plasma was achieved at the inner target and the electron temperature was reduced at the outer target.For locations R_(2) and R_(3),impurity B showed a more pronounced effect on the heat flux at the far-SOL of the outer target.Further analysis indicated that Ne atoms came mainly from the recycling sources,whereas B atoms came mainly from injection,and that their distinct atomic distributions resulted from the difference in the ionization threshold and ionization mean free path.In addition,the radiation proportion of B in the divertor region was larger than that of Ne when the total radiation power was similar,which suggests that B has less influence on the core region.展开更多
Based on the independently developed true triaxial multi-physical field large-scale physical simulation system of in-situ injection and production,we conducted physical simulation of long-term multi-well injection and...Based on the independently developed true triaxial multi-physical field large-scale physical simulation system of in-situ injection and production,we conducted physical simulation of long-term multi-well injection and production in the hot dry rocks of the Gonghe Basin,Qinghai Province,NW China.Through multi-well connectivity experiments,the spatial distribution characteristics of the natural fracture system in the rock samples and the connectivity between fracture and wellbore were clarified.The injection and production wells were selected to conduct the experiments,namely one injection well and two production wells,one injection well and one production well.The variation of several physical parameters in the production well was analyzed,such as flow rate,temperature,heat recovery rate and fluid recovery.The results show that under the combination of thermal shock and injection pressure,the fracture conductivity was enhanced,and the production temperature showed a downward trend.The larger the flow rate,the faster the decrease.When the local closed area of the fracture was gradually activated,new heat transfer areas were generated,resulting in a lower rate of increase or decrease in the mining temperature.The heat recovery rate was mainly controlled by the extraction flow rate and the temperature difference between injection and production fluid.As the conductivity of the leak-off channel increased,the fluid recovery of the production well rapidly decreased.The influence mechanisms of dominant channels and fluid leak-off on thermal recovery performance are different.The former limits the heat exchange area,while the latter affects the flow rate of the produced fluid.Both of them are important factors affecting the long-term and efficient development of hot dry rock.展开更多
The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs si...The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs significantly from that observed in sand gas condensate reservoirs. However, studies on improving the recovery of fractured gas condensate reservoirs are limited;thus, the impact of retrograde vaporization on condensate within fractured metamorphic buried-hill reservoirs remains unclear. To address this gap, a series of gas injection experiments are conducted in pressure-volume-temperature(PVT) cells and long-cores to investigate the retrograde vaporization effect of condensate using different gas injection media in fractured gas condensate reservoirs. We analyze the variation in condensate volume, gas-to-oil ratio, and condensate recovery during gas injection and examine the influence of various gas injection media(CO_(2), N_(2), and dry gas) under different reservoir properties and varying gas injection times. The results demonstrate that the exchange of components between injected gas and condensate significantly influences condensate retrograde vaporization in the formation. Compared with dry gas injection and N_(2) injection,CO_(2) injection exhibits a superior retrograde vaporization effect. At a CO_(2) injection volume of 1 PV, the percentage shrinkage volume of condensate is 13.82%. Additionally, at the maximum retrograde condensation pressure, CO_(2) injection can increase the recovery of condensate by 22.4%. However, the condensate recovery is notably lower in fractured gas condensate reservoirs than in homogeneous reservoirs, owing to the creation of dominant gas channeling by fractures, which leads to decreased condensate recovery. Regarding gas injection timing, the effect of gas injection at reservoir pressure on improving condensate recovery is superior to that of gas injection at the maximum retrograde condensation pressure. This research provides valuable guidance for designing gas injection development plans and dynamic tracking adjustments for fractured gas condensate reservoirs.展开更多
The nozzle inner-flow characteristic of the“spray G”injector was studied by the computational fluid dynamics(CFD)simulation,and the sensitivity of cycle fuel mass to the conicity and entrance radius of the nozzle ho...The nozzle inner-flow characteristic of the“spray G”injector was studied by the computational fluid dynamics(CFD)simulation,and the sensitivity of cycle fuel mass to the conicity and entrance radius of the nozzle hole were analyzed.Results show that the inner conicity of nozzle hole inhibits the development of cavitation phenomena,and increases the injection rate.While the outer conicity of nozzle hole promotes the diffusion of cavita-tion,leading to reductions of the liquid volume fraction of the nozzle outlet and the local flow resistance of the nozzle hole.The sensitivity of cycle fuel mass to inner-cone nozzle hole is stronger than that of the outer-cone noz-zle,especially at the smaller hole conicity.The increase of injection pressure enhances the sensitivity of the injection characteristics to the nozzle hole structure,in which inner-cone nozzle has higher sensitivity coefficient than the outer-cone nozzle hole.However,the increase of injection pressure aggravates the offset of liquid jet to the nozzle axis of the outer-cone nozzle hole.With the increase of the inner conicity of nozzle,the sensitivity of the injection characteristics to the entrance radius of the hole decreases.With the increase of the outer conicity of nozzle hole,the sensitivity of the injection characteristics to the entrance radius of the hole increases.展开更多
A series of experiments and numerical simulations are carried out in a high-speed axial compressor to systematically investigate the influence and underlying flow mechanisms of micro tip injection on enhancing compres...A series of experiments and numerical simulations are carried out in a high-speed axial compressor to systematically investigate the influence and underlying flow mechanisms of micro tip injection on enhancing compressor stability.Different geometric structures of micro tip injection have been investigated,including the axial positions of injector port,injected mass flow rate and injector diameter.First,seven designed micro tip injection structures and one solid wall casing are tested in the compressor test rig to elucidate the influence of different micro tip injection parameters on the compressor stability.Then,numerical simulations are conducted to analyze the underlying flow mechanisms of micro tip injection with different design parameters on enhancing the compressor stability.The experimental and numerical investigation reveal that when the injection port is located upstream of the low-speed region,the compressor stability is significantly enhanced.The tip injection with larger injected mass flow can obtain higher stall margin improvement.Smaller injector diameter produces higher injection momentum and velocity,contributing to greater improvement on the compressor stability.展开更多
A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with e...A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with experimental data.The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed.In the spill control valve mode,main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time.In the needle control valve mode,main-injection fuel quantity increases with rising multi-injection dwell time;this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths.Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes;the variation in main-injection quantity is in the range of 1 mm3.展开更多
Polymer flooding has been proven to effectively improve oil recovery in the Bohai Oil Field. However, due to high oil viscosity and significant formation heterogeneity, it is necessary to further improve the displacem...Polymer flooding has been proven to effectively improve oil recovery in the Bohai Oil Field. However, due to high oil viscosity and significant formation heterogeneity, it is necessary to further improve the displacement effectiveness of polymer flooding in heavy oil reservoirs in the service life of offshore platforms. In this paper, the effects of the water/oil mobility ratio in heavy oil reservoirs and the dimensionless oil productivity index on polymer flooding effectiveness were studied utilizing rel- ative permeability curves. The results showed that when the water saturation was less than the value, where the water/oil mobility ratio was equal to 1, polymer flooding could effectively control the increase of fractional water flow, which meant that the upper limit of water/oil ratio suitable for polymer flooding should be the value when the water/oil mobility ratio was equal to 1. Mean while, by injecting a certain volume of water to create water channels in the reservoir, the polymer flooding would be the most effective in improving sweep efficiency, and lower the fractional flow of water to the value corresponding to △Jmax. Considering the service life of the platform and the polymer mobility control capacity, the best polymer injection timing for heavy oil reservoirs was optimized. It has been tested for reservoirs with crude oil viscosity of 123 and 70 mPa s, the optimum polymer flooding effec- tiveness could be obtained when the polymer floods were initiated at the time when the fractional flow of water were 10 % and 25 %, respectively. The injection timing range for polymer flooding was also theoretically analyzed for the Bohai Oil Field utilizing which provided methods for effectiveness. relative permeability curves, improving polymer flooding展开更多
InGaN-based light-emitting diodes with p-GaN and p-A1GaN hole injection layers are numerically studied using the APSYS simulation software. The simulation results indicate that light-emitting diodes with p-A1GaN hole ...InGaN-based light-emitting diodes with p-GaN and p-A1GaN hole injection layers are numerically studied using the APSYS simulation software. The simulation results indicate that light-emitting diodes with p-A1GaN hole injection layers show superior optical and electrical performance, such as an increase in light output power, a reduction in current leakage and alleviation of efficiency droop. These improvements can be attributed to the p-A1GaN serving as hole injection layers, which can alleviate the band bending induced by the polarization field, thereby improving both the hole injection efficiency and the electron blocking efficiency.展开更多
Based on the traditional numerical simulation and optimization algorithms,in combination with the layered injection and production"hard data"monitored at real time by automatic control technology,a systemati...Based on the traditional numerical simulation and optimization algorithms,in combination with the layered injection and production"hard data"monitored at real time by automatic control technology,a systematic approach for detailed water injection design using data-driven algorithms is proposed.First the data assimilation technology is used to match geological model parameters under the constraint of observed well dynamics;the flow relationships between injectors and producers in the block are calculated based on automatic identification method for layered injection-production flow relationship;multi-layer and multi-direction production splitting technique is used to calculate the liquid and oil production of producers in different layers and directions and obtain quantified indexes of water injection effect.Then,machine learning algorithms are applied to evaluate the effectiveness of water injection in different layers of wells and to perform the water injection direction adjustment.Finally,the particle swarm algorithm is used to optimize the detailed water injection plan and to make production predictions.This method and procedure make full use of the automation and intelligence of data-driven and machine learning algorithms.This method was used to match the data of a complex faulted reservoir in eastern China,achieving a fitting level of 85%.The cumulative oil production in the example block for 12 months after optimization is 8.2%higher than before.This method can help design detailed water injection program for mature oilfields.展开更多
Permeability sensitivity to stress experiments were conducted on standard core samples taken from Wen 23 Gas Storage at multi-cycle injection and production conditions of the gas storage to study the change pattern of...Permeability sensitivity to stress experiments were conducted on standard core samples taken from Wen 23 Gas Storage at multi-cycle injection and production conditions of the gas storage to study the change pattern of stress sensitivity of permeability.A method for calculating permeability under overburden pressure in the multi-cycle injection and production process was proposed,and the effect of stress sensitivity of reservoir permeability on gas well injectivity and productivity in UGS was analyzed.Retention rate of permeability decreased sharply first and then slowly with the increase of the UGS cycles.The stress sensitivity index of permeability decreased with the increase of cycle number of net stress variations in the increase process of net stress.The stress sensitivity index of permeability hardly changed with the increase of cycle number of net stress variations in the decrease process of net stress.With the increase of cycle number of net stress variation,the stress sensitivity index of permeability in the increase process of net stress approached that in the decrease process of net stress.The lower the reservoir permeability,the greater the irreversible permeability loss rate,the stronger the cyclic stress sensitivity,and the higher the stress sensitivity index of the reservoir,the stronger the reservoir stress sensitivity.The gas zones with permeability lower than 0.3’10-3 mm2 are not suitable as gas storage regions.Stress sensitivity of reservoir permeability has strong impact on gas well injectivity and productivity and mainly in the first few cycles.展开更多
BACKGROUND: Inadvertent intra-arterial injection of illicit substances is a known complication of injection drug use and can lead to severe complications, including infection, ischemia and compartment syndrome. Identi...BACKGROUND: Inadvertent intra-arterial injection of illicit substances is a known complication of injection drug use and can lead to severe complications, including infection, ischemia and compartment syndrome. Identifying complications of intra-arterial injection can be difficult, as clinical manifestations overlap with other more common conditions such as cellulitis and soft tissue infection, and a history of injection drug use is frequently not disclosed.METHODS: A 37-year-old male patient presented with 24 hours of right hand pain, erythema and swelling. Despite classic "track marks", he denied a history of injection drug use, and vascular insults were not initially considered. After failing to respond to three days of aggressive treatment for suspected deep-space infection, an arteriogram demonstrated findings consistent with digital ischemia of embolic etiology.RESULTS: As a result of the delay in diagnosis, the lesion was not amenable to reperfusion and the patient required amputation of the distal digit.CONCLUSION: Practitioners should be alert to the possibility of intra-arterial injection and resulting complications when evaluating unusual extremity infections or unexplained ischemic symptoms, even in the absence of a definite history of injection drug use.展开更多
The effects of various split injection strategies on the opposed-piston opposed-cylinder(OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools.The five rate-...The effects of various split injection strategies on the opposed-piston opposed-cylinder(OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools.The five rate-shaped main injections were used in split injection strategies.The results show that ignition delay from a rectangular injection rate is the shortest.Maximum pressure of the trapezoid injection rate is the largest.And the NOx emission of the rectangular injection rate is the largest.Meanwhile,the soot emission of the trapezoid injection rate is the least among the five injection rates.展开更多
Concerns about environmental pollution and energy shortages have increased worldwide. One approach to reduce CO2 emissions from gasoline engines is to achieve stratified charge combustion with various injection ratios...Concerns about environmental pollution and energy shortages have increased worldwide. One approach to reduce CO2 emissions from gasoline engines is to achieve stratified charge combustion with various injection ratios using port fuel injection （PFI） and direct injection. The combustion and emission characteristics of a 4-valve direct injection spark ignition （DISI） engine equipped with a dual injection system were investigated while the injection ratio was varied. When the direct injection ratio increased, the lean limit A/F was extended. This suggests that the dual injection gasoline engine with both PFI and direct injection can meet severe vehicle emission and fuel economy requirements. The dual injection system had higher combustion pressure than that of either a conventional or direct injection systems. Therefore, the engine power of a dual injection DISI engine would be higher than that of a single injection DISI engine. However, NOx emissions increased compared with the emission levels in both PFI and DISI systems.展开更多
Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Met...Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Methods Patients were placed in a DI group and control group.The DI group was given DI and the control group was given physiologic saline.The administration lasted 4 to 6 days in both groups after PCI.Cardiac magnetic resonance(CMR)was carried out during the perioperative period(7±2 days).The primary endpoint of the study was myocardial infarct size(IS)imaged on delayed-enhancement CMR.The secondary endpoint was major adverse cardiac events observed 6 months after PCI.Results In total,160 high-risk NR patients were enrolled,and 110 patients completed the CMR examination.According to postoperative CMR,the Myocardial Salvage Index and left ventricular ejection fraction were higher in the DI group(0.57±0.13 vs.0.48±0.17,P<0.01;49.3%±6.9%vs.46.2%±7.7%,P=0.03,respectively),whereas the IS was lower(19.7%±5.6%vs.22.2%±6.5%,P=0.04),compared with that in the control group.These differences were observed to be significant.After 6 months,the prevalence of major adverse cardiac events in the DI group decreased compared with that in the control group,but the differences were not observed to be significant(P>0.05).Conclusion The application of DI can reduce the myocardial infarct size in STEMI patients at a high risk of NR during primary PCI.展开更多
Surface subsidence is a typical ground movement due to longwall mining, which causes a series of environmental problems and hazards. In China, intensive coal extractions are commonly operated under dense-populated coa...Surface subsidence is a typical ground movement due to longwall mining, which causes a series of environmental problems and hazards. In China, intensive coal extractions are commonly operated under dense-populated coalfields, which exacerbates the negative subsequences resulted from surface settlement. Therefore, effective approaches to control the ground subsidence are in urgent need for the Chinese coal mining industry. This paper presents a newly developed subsidence control technology: isolated overburden grout injection, including the theory, technique and applications. Relevant procedures such as injection system design, grouting material selection, borehole layout, grout take estimation and injection process design are proposed. The applicability of this technology has been demonstrated through physical modelling, field measurements, and case studies. Since 2009, the technology has been successfully applied to 14 longwall areas in 9 Chinese coal mines. The ultimate surface subsidence factors vary from 0.10 to 0.15. This method has a great potential to be popularized and performed where longwall mining are implemented under villages and ground infrastructures.展开更多
Neutral beam injection （NBI） system with two neutral beam injections will be con- structed on the Experimental Advanced Superconducting Tokamak （EAST） in two stages for high power auxiliary plasmas heating and non...Neutral beam injection （NBI） system with two neutral beam injections will be con- structed on the Experimental Advanced Superconducting Tokamak （EAST） in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2-4 MW beam power with 50-80 keV beam energy in 10-100 s pulse length. Each elements of the NBI system are presented in this contribution.展开更多
Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects ...Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects the prognosis of patients.Current treatment experience regarding these infections is scarce.Case presentation:We report a case of severe intracranial infection of XDR Acinetobacter baumannii(A.baumannii)that was treated by intravenous(IV)injection,sequential intraventricular(IVT)injection of tigecycline and polymyxin B,and other anti-infective drugs.Good results were obtained,and the patient was eventually discharged from the hospital.This case is characterized by intracranial infection.Conclusions:The polymyxin B IV+IVT pathway is an ideal treatment strategy for XDR A.baumannii.The tigecycline IVT pathway is also a safe treatment option.展开更多
基金Project supported in part by the National Natural Science Foundation of China(Grant Nos.62471144 and 62071124)in part by the Conselho Nacional de Desenvolvimento Científico e Tecnológico(BR)(CNPq)(Grant No.315546/2021-2)。
文摘The combination therapy of magnetic hyperthermia and thermosensitive liposomes(TSL)is an emerging and effective cancer treatment method.The heat generation of magnetic nanoparticles(MNPs)due to an external alternating magnetic field can not only directly damage tumor cells,but also serves as a triggering factor for the release of doxorubicin from TSL.The aim of this study is to investigate the effects in the degree of tumor cell damage of two proposed injection strategies that consider intravenous administration.Since both MNPs and TSL enter the tumor region intravenously,this study establishes a biological geometric model based on an experiment-based vascular distribution.Furthermore,this study derives the flow velocity of interstitial fluid after coupling the pressure distribution inside blood vessels and the pressure distribution of interstitial fluid,which then provides the convective velocity for the calculation of subsequent nanoparticle concentration.Different injection strategies for the proposed approach are evaluated by drug delivery result,temperature distribution,and tumor cell damage.Simulation results demonstrate that the proposed delayed injection strategy after optimization can not only result in a wider distribution for MNPs and TSL due to the sufficient diffusion time,but also improves the distribution of the temperature and drug concentration fields for the overall efficacy of combination therapy.
基金supported by National Natural Science Foundation of China (No. 52204049)Natural Science Foundation of Sichuan Province (No. 2024NSFSC0960)Ministry of Science and Higher Education of the Russian Federation under Agreement No. 075-15-2022-299 within the Framework of the Development Program for a World-Class Research Center “Efficient development of the global liquid hydrocarbon reserves”。
文摘Air injection technique for developing shale oil has gained significant attention. However, the ability of the heat front to consistently propagate within the shale during air injection remains uncertain. To address this, we investigated the heat front propagation within oil-detritus mixtures, shale cores, and fractured shale cores using a self-designed combustion tube(CT) and experimental schemes. By integrating the results obtained from high-pressure differential scanning calorimetry and CT, we developed a comprehensive reaction kinetics model to accurately analyze the main factors influencing the heat front propagation within fractured shale. The findings revealed that in the absence of additional fractures, the heat front failed to propagate within the tight shale. The flow of gases and liquids towards the shale core was impeded, resulting in the formation of a high-pressure zone at the front region of the shale. This pressure buildup significantly hindered air injection, leading to inadequate oxygen supply and the extinguishment of the heat front. However, the study demonstrated the stable propagation of the heat front within the oil-detritus mixtures, indicating the good combustion activity of the shale oil.Furthermore, the heat front successfully propagated within the fractured shale, generating a substantial amount of heat that facilitated the creation of fractures and enhanced gas injection and shale oil flow. It was important to note that after the heat front passed through the shale, the combustion intensity decreased. The simulation results indicated that injecting air into the main fracturing layers of the shale oil reservoir enabled the establishment of a stable heat front. Increasing the reservoir temperature(from 63 to 143℃) and oxygen concentration in the injected gas(from 11% to 21%) promoted notable heat front propagation and increased the average temperature of the heat front. It was concluded that temperature and oxygen concentration had the most important influence on the heat front propagation, followed by pressure and oil saturation.
基金supported by the National Natural Science Foundation of China(Nos.52074249,U1663206,52204069)Fundamental Research Funds for the Central Universities。
文摘Nanoparticles(NPs)have gained significant attention as a functional material due to their ability to effectively enhance pressure reduction in injection processes in ultra-low permeability reservoirs.NPs are typically studied in controlled laboratory conditions,and their behavior in real-world,complex environments such as ultra-low permeability reservoirs,is not well understood due to the limited scope of their applications.This study investigates the efficacy and underlying mechanisms of NPs in decreasing injection pressure under various injection conditions(25—85℃,10—25 MPa).The results reveal that under optimal injection conditions,NPs effectively reduce injection pressure by a maximum of 22.77%in core experiment.The pressure reduction rate is found to be positively correlated with oil saturation and permeability,and negatively correlated with temperature and salinity.Furthermore,particle image velocimetry(PIV)experiments(25℃,atmospheric pressure)indicate that the pressure reduction is achieved by NPs through the reduction of wall shear resistance and wettability change.This work has important implications for the design of water injection strategies in ultra-low permeability reservoirs.
基金Project supported by the National Key R&D Program of China(Grant No.2019YFE03030004)the National Natural Science Foundation of China(Grant No.12275040)+1 种基金the Users with Excellence Program of Hefei Science Center CAS(Grant No.2020HSC-UE010)This research is also sponsored in part by the U.S.Department of Energy under contract DEAC02-09CH11466.
文摘Based on the EAST equilibrium,the effects of boron(B)and neon(Ne)injected at different locations on the target heat load,and the distributions of B and Ne particles were investigated by transport code SOLPS-ITER.It was found that the B injection was more sensitive to the injection location for heat flux control than impurity Ne.The high electron and ion densities near the inner target in the discharge with impurity B injected from over X-point(R_(1))led to plasma detachment only at the inner target,and the localized B ions in the cases with injection from outer target location(R_(2))and upstream location(R_(3))led to far-SOL detachment at the outer target,but not at the inner target.In contrast,for Ne,the spatial distributions of Ne ions and electrons were found to be similar in all the cases at the three injection locations,and the detached plasma was achieved at the inner target and the electron temperature was reduced at the outer target.For locations R_(2) and R_(3),impurity B showed a more pronounced effect on the heat flux at the far-SOL of the outer target.Further analysis indicated that Ne atoms came mainly from the recycling sources,whereas B atoms came mainly from injection,and that their distinct atomic distributions resulted from the difference in the ionization threshold and ionization mean free path.In addition,the radiation proportion of B in the divertor region was larger than that of Ne when the total radiation power was similar,which suggests that B has less influence on the core region.
基金Supported by the National Natural Science Foundation of China(52192622,52304003).
文摘Based on the independently developed true triaxial multi-physical field large-scale physical simulation system of in-situ injection and production,we conducted physical simulation of long-term multi-well injection and production in the hot dry rocks of the Gonghe Basin,Qinghai Province,NW China.Through multi-well connectivity experiments,the spatial distribution characteristics of the natural fracture system in the rock samples and the connectivity between fracture and wellbore were clarified.The injection and production wells were selected to conduct the experiments,namely one injection well and two production wells,one injection well and one production well.The variation of several physical parameters in the production well was analyzed,such as flow rate,temperature,heat recovery rate and fluid recovery.The results show that under the combination of thermal shock and injection pressure,the fracture conductivity was enhanced,and the production temperature showed a downward trend.The larger the flow rate,the faster the decrease.When the local closed area of the fracture was gradually activated,new heat transfer areas were generated,resulting in a lower rate of increase or decrease in the mining temperature.The heat recovery rate was mainly controlled by the extraction flow rate and the temperature difference between injection and production fluid.As the conductivity of the leak-off channel increased,the fluid recovery of the production well rapidly decreased.The influence mechanisms of dominant channels and fluid leak-off on thermal recovery performance are different.The former limits the heat exchange area,while the latter affects the flow rate of the produced fluid.Both of them are important factors affecting the long-term and efficient development of hot dry rock.
文摘The gas field in the Bohai Bay Basin is a fractured metamorphic buried-hill reservoir with dual-media characteristics. The retrograde vaporization mechanism observed in this type of gas condensate reservoir differs significantly from that observed in sand gas condensate reservoirs. However, studies on improving the recovery of fractured gas condensate reservoirs are limited;thus, the impact of retrograde vaporization on condensate within fractured metamorphic buried-hill reservoirs remains unclear. To address this gap, a series of gas injection experiments are conducted in pressure-volume-temperature(PVT) cells and long-cores to investigate the retrograde vaporization effect of condensate using different gas injection media in fractured gas condensate reservoirs. We analyze the variation in condensate volume, gas-to-oil ratio, and condensate recovery during gas injection and examine the influence of various gas injection media(CO_(2), N_(2), and dry gas) under different reservoir properties and varying gas injection times. The results demonstrate that the exchange of components between injected gas and condensate significantly influences condensate retrograde vaporization in the formation. Compared with dry gas injection and N_(2) injection,CO_(2) injection exhibits a superior retrograde vaporization effect. At a CO_(2) injection volume of 1 PV, the percentage shrinkage volume of condensate is 13.82%. Additionally, at the maximum retrograde condensation pressure, CO_(2) injection can increase the recovery of condensate by 22.4%. However, the condensate recovery is notably lower in fractured gas condensate reservoirs than in homogeneous reservoirs, owing to the creation of dominant gas channeling by fractures, which leads to decreased condensate recovery. Regarding gas injection timing, the effect of gas injection at reservoir pressure on improving condensate recovery is superior to that of gas injection at the maximum retrograde condensation pressure. This research provides valuable guidance for designing gas injection development plans and dynamic tracking adjustments for fractured gas condensate reservoirs.
文摘The nozzle inner-flow characteristic of the“spray G”injector was studied by the computational fluid dynamics(CFD)simulation,and the sensitivity of cycle fuel mass to the conicity and entrance radius of the nozzle hole were analyzed.Results show that the inner conicity of nozzle hole inhibits the development of cavitation phenomena,and increases the injection rate.While the outer conicity of nozzle hole promotes the diffusion of cavita-tion,leading to reductions of the liquid volume fraction of the nozzle outlet and the local flow resistance of the nozzle hole.The sensitivity of cycle fuel mass to inner-cone nozzle hole is stronger than that of the outer-cone noz-zle,especially at the smaller hole conicity.The increase of injection pressure enhances the sensitivity of the injection characteristics to the nozzle hole structure,in which inner-cone nozzle has higher sensitivity coefficient than the outer-cone nozzle hole.However,the increase of injection pressure aggravates the offset of liquid jet to the nozzle axis of the outer-cone nozzle hole.With the increase of the inner conicity of nozzle,the sensitivity of the injection characteristics to the entrance radius of the hole decreases.With the increase of the outer conicity of nozzle hole,the sensitivity of the injection characteristics to the entrance radius of the hole increases.
基金supported by National Natural Science Foundation of China(No.52076179)National Science and Technology Major Projects of China(No.J2019-I-0011).
文摘A series of experiments and numerical simulations are carried out in a high-speed axial compressor to systematically investigate the influence and underlying flow mechanisms of micro tip injection on enhancing compressor stability.Different geometric structures of micro tip injection have been investigated,including the axial positions of injector port,injected mass flow rate and injector diameter.First,seven designed micro tip injection structures and one solid wall casing are tested in the compressor test rig to elucidate the influence of different micro tip injection parameters on the compressor stability.Then,numerical simulations are conducted to analyze the underlying flow mechanisms of micro tip injection with different design parameters on enhancing the compressor stability.The experimental and numerical investigation reveal that when the injection port is located upstream of the low-speed region,the compressor stability is significantly enhanced.The tip injection with larger injected mass flow can obtain higher stall margin improvement.Smaller injector diameter produces higher injection momentum and velocity,contributing to greater improvement on the compressor stability.
基金Supported by the Program for New Century Excellent Talents in University（NECT-11-0826） the National Natural Science Foundation of China（NSFC 51279037）+1 种基金 the Fundamental Research Funds for the Central Universities（HEUCFZ13） the Postdoctoral Science-research Developmental Foundation of Heilongjiang Province（LBH-Q12126）Acknowledgement The authors gratefully acknowledge vice Professor Yong Shi and Jun Sun＇s help in fuel injection experiment.
文摘A simulation model of an electronically controlled two solenoid valve fuel injection system for a diesel engine is established in the AMESim environment.The accuracy of the model is validated through comparison with experimental data.The influence of pre-injection control parameters on main-injection quantity under different control modes is analyzed.In the spill control valve mode,main-injection fuel quantity decreases gradually and then reaches a stable level because of the increase in multi-injection dwell time.In the needle control valve mode,main-injection fuel quantity increases with rising multi-injection dwell time;this effect becomes more obvious at high-speed revolutions and large main-injection pulse widths.Pre-injection pulse width has no obvious influence on main-injection quantity under the two control modes;the variation in main-injection quantity is in the range of 1 mm3.
基金supported by Open Fund (CRI2012RCPS0152CN) of State Key Laboratory of Offshore Oil Exploitationthe National Science and Technology Major Project (2011ZX05024-004-01)
文摘Polymer flooding has been proven to effectively improve oil recovery in the Bohai Oil Field. However, due to high oil viscosity and significant formation heterogeneity, it is necessary to further improve the displacement effectiveness of polymer flooding in heavy oil reservoirs in the service life of offshore platforms. In this paper, the effects of the water/oil mobility ratio in heavy oil reservoirs and the dimensionless oil productivity index on polymer flooding effectiveness were studied utilizing rel- ative permeability curves. The results showed that when the water saturation was less than the value, where the water/oil mobility ratio was equal to 1, polymer flooding could effectively control the increase of fractional water flow, which meant that the upper limit of water/oil ratio suitable for polymer flooding should be the value when the water/oil mobility ratio was equal to 1. Mean while, by injecting a certain volume of water to create water channels in the reservoir, the polymer flooding would be the most effective in improving sweep efficiency, and lower the fractional flow of water to the value corresponding to △Jmax. Considering the service life of the platform and the polymer mobility control capacity, the best polymer injection timing for heavy oil reservoirs was optimized. It has been tested for reservoirs with crude oil viscosity of 123 and 70 mPa s, the optimum polymer flooding effec- tiveness could be obtained when the polymer floods were initiated at the time when the fractional flow of water were 10 % and 25 %, respectively. The injection timing range for polymer flooding was also theoretically analyzed for the Bohai Oil Field utilizing which provided methods for effectiveness. relative permeability curves, improving polymer flooding
基金Project supported by the National Natural Science Foundation of China (Grant No. 50602018)the Science and Technology Program of Guangdong Province,China (Grant Nos. 2010B090400456,2009B011100003,and 2010A081002002)the Science and Technology Program of Guangzhou City,China (Grant No. 2010U1-D00191)
文摘InGaN-based light-emitting diodes with p-GaN and p-A1GaN hole injection layers are numerically studied using the APSYS simulation software. The simulation results indicate that light-emitting diodes with p-A1GaN hole injection layers show superior optical and electrical performance, such as an increase in light output power, a reduction in current leakage and alleviation of efficiency droop. These improvements can be attributed to the p-A1GaN serving as hole injection layers, which can alleviate the band bending induced by the polarization field, thereby improving both the hole injection efficiency and the electron blocking efficiency.
基金Supported by the Key Program of Petro China Exploration&Production Company(Grant No.kt2017-17-01-1 and kt2017-17-06-1)Consulting Project of Chinese Academy of Engineering(Grant No.2019-XZ-17)
文摘Based on the traditional numerical simulation and optimization algorithms,in combination with the layered injection and production"hard data"monitored at real time by automatic control technology,a systematic approach for detailed water injection design using data-driven algorithms is proposed.First the data assimilation technology is used to match geological model parameters under the constraint of observed well dynamics;the flow relationships between injectors and producers in the block are calculated based on automatic identification method for layered injection-production flow relationship;multi-layer and multi-direction production splitting technique is used to calculate the liquid and oil production of producers in different layers and directions and obtain quantified indexes of water injection effect.Then,machine learning algorithms are applied to evaluate the effectiveness of water injection in different layers of wells and to perform the water injection direction adjustment.Finally,the particle swarm algorithm is used to optimize the detailed water injection plan and to make production predictions.This method and procedure make full use of the automation and intelligence of data-driven and machine learning algorithms.This method was used to match the data of a complex faulted reservoir in eastern China,achieving a fitting level of 85%.The cumulative oil production in the example block for 12 months after optimization is 8.2%higher than before.This method can help design detailed water injection program for mature oilfields.
基金Supported by the Chongqing Technical Innovation and Application&Development Special Project(cstc2020jscx-msxmX0189)。
文摘Permeability sensitivity to stress experiments were conducted on standard core samples taken from Wen 23 Gas Storage at multi-cycle injection and production conditions of the gas storage to study the change pattern of stress sensitivity of permeability.A method for calculating permeability under overburden pressure in the multi-cycle injection and production process was proposed,and the effect of stress sensitivity of reservoir permeability on gas well injectivity and productivity in UGS was analyzed.Retention rate of permeability decreased sharply first and then slowly with the increase of the UGS cycles.The stress sensitivity index of permeability decreased with the increase of cycle number of net stress variations in the increase process of net stress.The stress sensitivity index of permeability hardly changed with the increase of cycle number of net stress variations in the decrease process of net stress.With the increase of cycle number of net stress variation,the stress sensitivity index of permeability in the increase process of net stress approached that in the decrease process of net stress.The lower the reservoir permeability,the greater the irreversible permeability loss rate,the stronger the cyclic stress sensitivity,and the higher the stress sensitivity index of the reservoir,the stronger the reservoir stress sensitivity.The gas zones with permeability lower than 0.3’10-3 mm2 are not suitable as gas storage regions.Stress sensitivity of reservoir permeability has strong impact on gas well injectivity and productivity and mainly in the first few cycles.
文摘BACKGROUND: Inadvertent intra-arterial injection of illicit substances is a known complication of injection drug use and can lead to severe complications, including infection, ischemia and compartment syndrome. Identifying complications of intra-arterial injection can be difficult, as clinical manifestations overlap with other more common conditions such as cellulitis and soft tissue infection, and a history of injection drug use is frequently not disclosed.METHODS: A 37-year-old male patient presented with 24 hours of right hand pain, erythema and swelling. Despite classic "track marks", he denied a history of injection drug use, and vascular insults were not initially considered. After failing to respond to three days of aggressive treatment for suspected deep-space infection, an arteriogram demonstrated findings consistent with digital ischemia of embolic etiology.RESULTS: As a result of the delay in diagnosis, the lesion was not amenable to reperfusion and the patient required amputation of the distal digit.CONCLUSION: Practitioners should be alert to the possibility of intra-arterial injection and resulting complications when evaluating unusual extremity infections or unexplained ischemic symptoms, even in the absence of a definite history of injection drug use.
基金Supported by the National Natural Science Foundation of China(51605447)
文摘The effects of various split injection strategies on the opposed-piston opposed-cylinder(OPOC)diesel engine combustion and emission characteristics have been studied numerically using AVL-Fire CFD tools.The five rate-shaped main injections were used in split injection strategies.The results show that ignition delay from a rectangular injection rate is the shortest.Maximum pressure of the trapezoid injection rate is the largest.And the NOx emission of the rectangular injection rate is the largest.Meanwhile,the soot emission of the trapezoid injection rate is the least among the five injection rates.
基金supported by the Industrial Strategic Technology Development Program, 10042559‘Development of fuel injector for 200 bar gasoline direct injection system’ funded by the Ministry of Trade, Industry & Energy (MI, Korea)
文摘Concerns about environmental pollution and energy shortages have increased worldwide. One approach to reduce CO2 emissions from gasoline engines is to achieve stratified charge combustion with various injection ratios using port fuel injection （PFI） and direct injection. The combustion and emission characteristics of a 4-valve direct injection spark ignition （DISI） engine equipped with a dual injection system were investigated while the injection ratio was varied. When the direct injection ratio increased, the lean limit A/F was extended. This suggests that the dual injection gasoline engine with both PFI and direct injection can meet severe vehicle emission and fuel economy requirements. The dual injection system had higher combustion pressure than that of either a conventional or direct injection systems. Therefore, the engine power of a dual injection DISI engine would be higher than that of a single injection DISI engine. However, NOx emissions increased compared with the emission levels in both PFI and DISI systems.
基金supported by grant from the Capital health research and development of special project (2016-15011)
文摘Objective To observe the effect of Danhong injection(DI)in patients with acute ST-segment elevation myocardial infarction(STEMI)at a high risk of no-reflow(NR)during primary percutaneous coronary intervention(PCI).Methods Patients were placed in a DI group and control group.The DI group was given DI and the control group was given physiologic saline.The administration lasted 4 to 6 days in both groups after PCI.Cardiac magnetic resonance(CMR)was carried out during the perioperative period(7±2 days).The primary endpoint of the study was myocardial infarct size(IS)imaged on delayed-enhancement CMR.The secondary endpoint was major adverse cardiac events observed 6 months after PCI.Results In total,160 high-risk NR patients were enrolled,and 110 patients completed the CMR examination.According to postoperative CMR,the Myocardial Salvage Index and left ventricular ejection fraction were higher in the DI group(0.57±0.13 vs.0.48±0.17,P<0.01;49.3%±6.9%vs.46.2%±7.7%,P=0.03,respectively),whereas the IS was lower(19.7%±5.6%vs.22.2%±6.5%,P=0.04),compared with that in the control group.These differences were observed to be significant.After 6 months,the prevalence of major adverse cardiac events in the DI group decreased compared with that in the control group,but the differences were not observed to be significant(P>0.05).Conclusion The application of DI can reduce the myocardial infarct size in STEMI patients at a high risk of NR during primary PCI.
基金financial support provided by the National Natural Science Foundation of China(51604258)is greatly appreciated
文摘Surface subsidence is a typical ground movement due to longwall mining, which causes a series of environmental problems and hazards. In China, intensive coal extractions are commonly operated under dense-populated coalfields, which exacerbates the negative subsequences resulted from surface settlement. Therefore, effective approaches to control the ground subsidence are in urgent need for the Chinese coal mining industry. This paper presents a newly developed subsidence control technology: isolated overburden grout injection, including the theory, technique and applications. Relevant procedures such as injection system design, grouting material selection, borehole layout, grout take estimation and injection process design are proposed. The applicability of this technology has been demonstrated through physical modelling, field measurements, and case studies. Since 2009, the technology has been successfully applied to 14 longwall areas in 9 Chinese coal mines. The ultimate surface subsidence factors vary from 0.10 to 0.15. This method has a great potential to be popularized and performed where longwall mining are implemented under villages and ground infrastructures.
基金supported by National Natural Science Foundation of China (No. 11075188)the Chinese Academy of Sciences Knowledge Innovation Project: the study of neutral beam steady-state operation of the key technical and physical problems
文摘Neutral beam injection （NBI） system with two neutral beam injections will be con- structed on the Experimental Advanced Superconducting Tokamak （EAST） in two stages for high power auxiliary plasmas heating and non-inductive current drive. Each NBI can deliver 2-4 MW beam power with 50-80 keV beam energy in 10-100 s pulse length. Each elements of the NBI system are presented in this contribution.
基金supported by grants from the National Natural Science Foundation of China(81571940,81741125)the Guangzhou Science and Technology Planning Project of China(201504281714528)PLA Logistics Research Project of China(CWH17L020,17CXZ008,18CXZ030)
文摘Background:Intracranial infection after craniotomy is one of the most serious postoperative complications,especially multidrug-resistant(MDR)or extensively drug-resistant(XDR)bacterial meningitis,and strongly affects the prognosis of patients.Current treatment experience regarding these infections is scarce.Case presentation:We report a case of severe intracranial infection of XDR Acinetobacter baumannii(A.baumannii)that was treated by intravenous(IV)injection,sequential intraventricular(IVT)injection of tigecycline and polymyxin B,and other anti-infective drugs.Good results were obtained,and the patient was eventually discharged from the hospital.This case is characterized by intracranial infection.Conclusions:The polymyxin B IV+IVT pathway is an ideal treatment strategy for XDR A.baumannii.The tigecycline IVT pathway is also a safe treatment option.
