In recent years, antibiotic pollution has become a serious threat to human health. In this study, a gas-liquid discharge plasma is developed to degrade ciprofloxacin hydrochloride in a multiphase mixed system containi...In recent years, antibiotic pollution has become a serious threat to human health. In this study, a gas-liquid discharge plasma is developed to degrade ciprofloxacin hydrochloride in a multiphase mixed system containing inorganic and organic impurities. The discharge characteristics are analyzed by diagnosing the applied voltage and discharge current waveforms, as well as the optical emission spectra. The work investigates how degradation efficiency is affected by applied voltage, gas flow rate, treatment time, initial concentration as well as the addition of γ-Al_(2)O_(3) pellets and peanut straw. After 70 min, the degradation efficiency of ciprofloxacin hydrochloride in the multiphase mixed system reached 99.6%. Its removal efficiency increases as the initial concentration decreases and the applied voltage increases. Besides, there is still a good degradation efficiency of ciprofloxacin hydrochloride with the addition of peanut straw.The degradation mechanism of ciprofloxacin hydrochloride is investigated through the analysis of degraded intermediates and reactive species.展开更多
Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant...Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.展开更多
This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissio...This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissions of passenger cars.The dynamic behaviors of these two types of vehicles are described using cellular automata(CA)models under open boundary conditions.Numerical simulations are carried out to obtain the phase diagrams of the bus system and the trajectories of buses and passenger cars before and after the implementation of the bus holding strategy under different probabilities of passenger cars entering a two-lane mixed traffic system.Then,we analyze the flow rate,satisfaction rate,and pollutant emission rates of passenger cars together with the performance of a mixed traffic system.The results show that the bus holding strategy can effectively alleviate bus bunching,whereas it has no significant impact on the flow rate and pollutant emission rates of passenger cars;the flow rate,satisfaction rate,and pollutant emission rates of passenger cars for either the traffic system or for each lane are influenced by the bus departure interval and the number of passengers arriving at bus stops.展开更多
Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a sim...Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge,due to the difficulty of achieving an optimal match between polymers and fillers.In this study,we incorporate a porous carbon-based zinc oxide composite(C@ZnO)into high-permeability polymers of intrinsic microporosity(PIMs)to fabricate MMMs.The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility,mitigating the formation of non-selective voids in the resulting MMMs.Concurrently,C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs.As a result,the CO_(2) permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer,while the CO_(2)/N_(2) and CO_(2)/CH_(4) selectivity reached 21.5 and 14.4,respectively,substantially surpassing the 2008 Robeson upper bound.Additionally,molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO_(2) affinity of C@ZnO.In summary,we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.展开更多
Aim To define a mixed redundant model(MRM), improving the reliability of C 3I system. Methods The model combined the technology characters of two? unit system with one warm stand by unit and function substitute s...Aim To define a mixed redundant model(MRM), improving the reliability of C 3I system. Methods The model combined the technology characters of two? unit system with one warm stand by unit and function substitute system. The reliability and availability equations of MRM were deduced. Results and Conclusion Compared with several other reliability models, it has obvious effect upon improving the system reliability. The effect? cost rate is very high among these models. The model can be used in reliability design, evaluation and check of C 3I system. Only a little attached cost is needed to improve C 3I system reliability effectively.展开更多
With using the cone and partial ordering t heory and mixed monotone operator theory, the existence and uniqueness for solut ion of systems of non-monotone binary nonliear operator equations are discussed. And the it...With using the cone and partial ordering t heory and mixed monotone operator theory, the existence and uniqueness for solut ion of systems of non-monotone binary nonliear operator equations are discussed. And the iterative sequences which converge to solution of systems of operator e quations and the error estimates are also given. Some corresponding results for the mixed monotone operations and the unary operator equations are improved and generalized.展开更多
This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investiga...This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investigated through in situ attenuated total reflectance Fourier transform infrared(ATRFTIR)spectroscopy combined with the two-dimensional correlation spectroscopy(2D-COS)and X-ray photoelectron spectroscopy(XPS).It has been found that BHA/DDA mixed collectors successfully separate ilmenite from titanaugite at a molar ratio of 8:1.Zeta potential experiments suggested that,in the presence of mixed collector system,the BHA-DDA complex adsorbed on the ilmenite surface via the chemically adsorbed BHA and the electrostatically adsorbed DDA,however,the complex adsorbed on the surface of titanaugite unstably.According to in situ ATR-FTIR combined with 2D-COS and XPS results,the interface assembly mechanism of BHA/DDA is summarized as:the function group of BHA molecules first binds to the metal sites on minerals to form bidentate ligand,then DDA co-adsorbed with BHA on the surface of minerals through hydrogen bonding.DDA may change the adsorption modes of some BHA on the ilmenite surface from four-membered ring to five-membered ring,while the modes on the titanaugite surface is true opposite.Finally,recommended adsorption configurations of the BHA/DDA complex on the two mineral surfaces are proposed.展开更多
A new temperature-resistant and salt-tolerant mixed surfactant system(referred to as the SS system)for enhancing oil recovery at the Tahe Oilfield(Xinjiang,China)was evaluated.Based on the analysis of the crude oil,th...A new temperature-resistant and salt-tolerant mixed surfactant system(referred to as the SS system)for enhancing oil recovery at the Tahe Oilfield(Xinjiang,China)was evaluated.Based on the analysis of the crude oil,the formation water and rock components in the Tahe Oilfield,the long-term thermal stability,salt tolerance and the ability to change the wettability,interfacial activity and oil washing efficiency of the mixed surfactant system were studied.The system contains the anionic surfactant SDB and another cationic surfactant SDY.When the total mass concentration of the SS solution is 0.15 wt%,m(SDB)/m(SDY)ratio is 1 to 1,and excellent efficiencies are achieved for oil washing for five kinds of Tahe Oilfield crude oils(more than 60%).In addition,after adding cationic surfactant,the adsorption capacity of the surfactant is further reduced,reaching 0.261 mg/g.The oil displacement experiments indicate that under a temperature of 150°C and a salinity of 24.6×104 mg/L,the SS system enhances the oil recovery by over 10%after water flooding.The SS anionic–cationic surfactant system is first presented in the open literature that can be successfully applied to obtain predictions of Tahe Oilfield carbonate reservoirs with a high temperature and high salinity.展开更多
This paper studies the phenomenon of stochastic resonance in an asymmetric bistable system with time-delayed feedback and mixed periodic signal by using the theory of signal-to-noise ratio in the adiabatic limit. A ge...This paper studies the phenomenon of stochastic resonance in an asymmetric bistable system with time-delayed feedback and mixed periodic signal by using the theory of signal-to-noise ratio in the adiabatic limit. A general approximate Fokker-Planck equation and the expression of the signal-to-noise ratio are derived through the small time delay approximation at both fundamental harmonics and mixed harmonics. The effects of the additive noise intensity Q, multiplicative noise intensity D, static asymmetry r and delay time T on the signal-to-noise ratio are discussed. It is found that the higher mixed harmonics and the static asymmetry r can restrain stochastic resonance, and the delay time τ can enhance stochastic resonance. Moreover, the longer the delay time τ is, the larger the additive noise intensity Q and the multiplicative noise intensity D are, when the stochastic resonance appears.展开更多
The interface phonon-polaritons in quantum well systems consisting of polar ternary mixed crystals are investi-gated. The numerical results of the interface phonon-polariton frequencies in the GaAs/AlxGa1-xAs, ZnSxSe1...The interface phonon-polaritons in quantum well systems consisting of polar ternary mixed crystals are investi-gated. The numerical results of the interface phonon-polariton frequencies in the GaAs/AlxGa1-xAs, ZnSxSe1-x/ZnS, and ZnxCd1-xSe/ ZnSe quantum well systems are obtained and discussed. It is shown that there are six branches of interface phonon-polariton modes distributed in three bulk phonon-polariton forbidden bands in the systems. The electric fields of interface phonon polaritons are also presented and show the interface locality of the modes. The effects of the ＇two-mode＇ and ＇one-mode＇ behaviours of the ternary mixed crystals on the interface phonon-polariton modes are shown in the dispersion curves.展开更多
This paper studies the nonlinear mixed problem for a class of symmetric hyperbolic systems with the boundary condition satisfying the dissipative condition about discontinuous data in higher dimension spaces, establis...This paper studies the nonlinear mixed problem for a class of symmetric hyperbolic systems with the boundary condition satisfying the dissipative condition about discontinuous data in higher dimension spaces, establishes the local existence theorem by using the method of a prior estimates, and obtains the structure of singularities of the solutions of such problems.展开更多
We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is ...We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is shown that the entanglement evolution is restricted by a set of monogamy relations. Furthermore, as quantified by the negativity, the entanglement dynamical property of the mixed entangled state of cavity photons is investigated. It is found that the three cavity photons can exhibit the phenomenon of entanglement sudden death （ESD）. However, compared with the evolution of a generalized three-qubit GHZ state which has the equal initial entanglement, the ESD time of mixed states is later than that of the pure state. Finally, we discuss the entanglement distribution in the multipartite system, and point out the intrinsic relation between the ESD of cavity photons and the entanglement sudden birth of reservoirs.展开更多
Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-e...Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-exist-ing species reponded similarly to climate factors,although S.saltuaria was more sensitive than A.faxoniana.The strong-est correlation was between S.saltuaria chronology and regional mean temperatures from June to November.Based on this relationship,a regional mean temperature from June to November for the period 1605-2016 was constructed.Reconstruction explained 37.3%of the temperature variance during th period 1961-2016.Six major warm periods and five major cold periods were identified.Spectral analysis detected significant interannual and multi-decadal cycles.Reconstruction also revealed the influence of the Atlantic Multi-decadal Oscillation,confirming its importance on climate change on the eastern Tibetan Plateau.展开更多
Considering the influences of collective dephasing, multilocal qutrit-flip, local qutrit-flip, and the combination of global mixed noise, we study the dynamics of entanglement and the phenomenon of distillability of s...Considering the influences of collective dephasing, multilocal qutrit-flip, local qutrit-flip, and the combination of global mixed noise, we study the dynamics of entanglement and the phenomenon of distillability of sudden death (DSD) in a qutrit-qutrit system under various decoherent noises. It is shown that the system always undergoes DSD when it interacts with multilocal and local qutrit-flip noise, and the time-determined bound entangled state is more dependent on different noises. Comparing with the cases of global mixed and collective dephasing noise,we conclude that the qutrit-flip noise is responsible for the DSD.展开更多
The necessity,basis,characteristic and methods of restoring and reestabling broadleaved/coniferous mixed forest ecosystem from the secondary forest of Mongolian oak(Quercus mongolica)are briefly set forth;then several...The necessity,basis,characteristic and methods of restoring and reestabling broadleaved/coniferous mixed forest ecosystem from the secondary forest of Mongolian oak(Quercus mongolica)are briefly set forth;then several effective methods of restoration and reestablishment are put forward and discussed as follows:openning up effect belt or island to establish horizontal order mixture;replenishing the blank niche to make vertical orderly mix-ture;planting artificial mixed forest to create biological diversity;developing ecological forestry,establishing integrated agroforestry ecosystem;and closing the land for forest and pre-serving some stands considering special conditions and demads.展开更多
Mixed matrix membranes(MMMs)could combine the advantages of both polymeric membranes and porousfillers,making them an effective alternative to conventional polymer membranes.However,interfacial incompatibility issues,s...Mixed matrix membranes(MMMs)could combine the advantages of both polymeric membranes and porousfillers,making them an effective alternative to conventional polymer membranes.However,interfacial incompatibility issues,such as the presence of interfacial voids,hardening of polymer chains,and blockage of micropores by polymers between common MMMsfillers and the polymer matrix,currently limit the gas sep-aration performance of MMMs.Ternary phase MMMs(consisting of afiller,an additive,and a matrix)made by adding a third compound,usually functionalized additives,can overcome the structural problems of binary phase MMMs and positively impact membrane separation performance.This review introduces the structure and fabrication processes for ternary MMMs,categorizes various nanofillers and the third component,and summarizes and analyzes in detail the CO_(2) separation performance of newly developed ternary MMMs based on both rubbery and glassy polymers.Based on this separation data,the challenges of ternary MMMs are also discussed.Finally,future directions for ternary MMMs are proposed.展开更多
Mixed redundancy strategies are generally used in cloud-based systems,with different node switch mechanisms from traditional fault-tolerant strategies.Existing studies often concentrate on optimizing a single strategy...Mixed redundancy strategies are generally used in cloud-based systems,with different node switch mechanisms from traditional fault-tolerant strategies.Existing studies often concentrate on optimizing a single strategy in cloud computing environment and ignore the impact of mixed redundancy strategies.Therefore,a model is proposed to evaluate and optimize the reliability and performance of cloud-based degraded systems subject to a mixed active and cold standby redundancy strategy.In this strategy,node switching is triggered by a continual monitoring and detection mechanism when active nodes fail.To evaluate the transient availability and the expected job completion rate of systems with such kind of strategy,a continuous-time Markov chain model is built on the state transition process and a numerical method is used to solve the model.To choose the optimal redundancy for the mixed strategy under system constraints,a greedy search algorithm is proposed after sensitivity analysis.Illustrative examples were presented to explain the process of calculating the transient probability of each system state and in turn,the availability and performance of the whole system.It was shown that the near-optimal redundancy solution could be obtained using the optimizationmethod.The comparison with optimization of the traditional mixed redundancy strategy proved that the system behavior was different using different kinds of mixed strategies and less redundancy was assigned for the new type of mixed strategy under the same system constraint.展开更多
The transient behaviors of traditional adaptive control may be very poor in general. A practically feasible approach to improve the transient performances is the adoption of adaptive switc- hing control. For a typical...The transient behaviors of traditional adaptive control may be very poor in general. A practically feasible approach to improve the transient performances is the adoption of adaptive switc- hing control. For a typical class of nonlinear systems disturbed by random noises, mixed multiple models consisting of adaptive model and fixed models were considered to design the switching con- trol law. Under certain assumptions, the nonlinear system with the switching control law was proved rigorously to be stable and optimal A simulation example was provided to compare the performance of the switching control and the traditional adaptive control.展开更多
Magnetic hysteresis and compensation behavior of a mixed spin-（1, 3/2） Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The e...Magnetic hysteresis and compensation behavior of a mixed spin-（1, 3/2） Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The effect of random crystal field, ferromagnetic and ferrimagnetic exchange interaction on hysteresis loops and compensation phenomenon are discussed. A number of characteristic phenomena have been reported such as the observation of triple hysteresis loops at low temperatures and for negative values of random crystal field. Critical and double compensation temperatures have been also found. The obtained results are also compared to some previous works.展开更多
Deep vein thrombosis(DVT)is a manifestation of venous thromboembolism,which can result from long-term bed and lead to pulmonary embolism(PE),stroke,mesenteric artery embolis,etc.Patients after surgery without bed-off ...Deep vein thrombosis(DVT)is a manifestation of venous thromboembolism,which can result from long-term bed and lead to pulmonary embolism(PE),stroke,mesenteric artery embolis,etc.Patients after surgery without bed-off activity may prone to thrombosis,but traditional anticoagulant therapy is a contraindication for them because of high risk of postoperative hemorrhage.Inferior vena cava filter(IVCF)implantation is the most effective method to intercept thrombosis from lower limb and to prevent PE.However,radiation and contrast agent limit its application.Our team have successfully performed an IVCF implantation guided by a mixed-reality(MR)system,[1]which is a chance for critically ill patients to allow the IVCF implantation exposed under no Xray and require no contrast agent.5G can help remote holographic projection images between distant range,meeting the needs of experts to guide the operation of critically ill patients.We describe a case of weak woman after neurosurgery who can not tolerate traditional interventional surgery to prevent DVT from falling off.We performed a mixed-reality system guided IVCF implantation under remote guidance of 5G communication.展开更多
基金supported by National Natural Science Foundations of China (Nos. 52307163 and 12305279)the China Postdoctoral Science Foundation (Nos. 2023M740498 and 2022M710590)Postdoctoral Fellowship Program of CPSF (No. GZC20230348)。
文摘In recent years, antibiotic pollution has become a serious threat to human health. In this study, a gas-liquid discharge plasma is developed to degrade ciprofloxacin hydrochloride in a multiphase mixed system containing inorganic and organic impurities. The discharge characteristics are analyzed by diagnosing the applied voltage and discharge current waveforms, as well as the optical emission spectra. The work investigates how degradation efficiency is affected by applied voltage, gas flow rate, treatment time, initial concentration as well as the addition of γ-Al_(2)O_(3) pellets and peanut straw. After 70 min, the degradation efficiency of ciprofloxacin hydrochloride in the multiphase mixed system reached 99.6%. Its removal efficiency increases as the initial concentration decreases and the applied voltage increases. Besides, there is still a good degradation efficiency of ciprofloxacin hydrochloride with the addition of peanut straw.The degradation mechanism of ciprofloxacin hydrochloride is investigated through the analysis of degraded intermediates and reactive species.
基金financially supported by National Natural Science Foundation of China(No.22302229)Beijing Municipal Excellent Talent Training Funds Youth Advanced Individual Project(No.2018000020124G163)。
文摘Emulsification is one of the important mechanisms of surfactant flooding. To improve oil recovery for low permeability reservoirs, a highly efficient emulsification oil flooding system consisting of anionic surfactant sodium alkyl glucosyl hydroxypropyl sulfonate(APGSHS) and zwitterionic surfactant octadecyl betaine(BS-18) is proposed. The performance of APGSHS/BS-18 mixed surfactant system was evaluated in terms of interfacial tension, emulsification capability, emulsion size and distribution, wettability alteration, temperature-resistance and salt-resistance. The emulsification speed was used to evaluate the emulsification ability of surfactant systems, and the results show that mixed surfactant systems can completely emulsify the crude oil into emulsions droplets even under low energy conditions. Meanwhile,the system exhibits good temperature and salt resistance. Finally, the best oil recovery of 25.45% is achieved for low permeability core by the mixed surfactant system with a total concentration of 0.3 wt%while the molar ratio of APGSHS:BS-18 is 4:6. The current study indicates that the anionic/zwitterionic mixed surfactant system can improve the oil flooding efficiency and is potential candidate for application in low permeability reservoirs.
基金Project supported by the National Natural Science Foundation of China(Grant No.52172314)the Natural Science Foundation of Liaoning Province,China(Grant No.2022-MS-150)the Special Funding Project of Taishan Scholar Engineering.
文摘This paper investigates the impacts of a bus holding strategy on the mutual interference between buses and passenger cars in a non-dedicated bus route,as well as the impacts on the characteristics of pollutant emissions of passenger cars.The dynamic behaviors of these two types of vehicles are described using cellular automata(CA)models under open boundary conditions.Numerical simulations are carried out to obtain the phase diagrams of the bus system and the trajectories of buses and passenger cars before and after the implementation of the bus holding strategy under different probabilities of passenger cars entering a two-lane mixed traffic system.Then,we analyze the flow rate,satisfaction rate,and pollutant emission rates of passenger cars together with the performance of a mixed traffic system.The results show that the bus holding strategy can effectively alleviate bus bunching,whereas it has no significant impact on the flow rate and pollutant emission rates of passenger cars;the flow rate,satisfaction rate,and pollutant emission rates of passenger cars for either the traffic system or for each lane are influenced by the bus departure interval and the number of passengers arriving at bus stops.
基金financial support from the National Natural Science Foundation of China(Nos.22108258 and 52003251)Program for Science&Technology Innovation Talents in Universities of Henan Province(24HASTIT004)+1 种基金Outstanding Youth Fund of Henan Scientific Committee(222300420085)Science and Technology Joint Project of Henan Province(222301420041)。
文摘Mixed matrix membranes(MMMs)have demonstrated significant promise in energy-intensive gas separations by amalgamating the unique properties of fillers with the facile processability of polymers.However,achieving a simultaneous enhancement of permeability and selectivity remains a formidable challenge,due to the difficulty of achieving an optimal match between polymers and fillers.In this study,we incorporate a porous carbon-based zinc oxide composite(C@ZnO)into high-permeability polymers of intrinsic microporosity(PIMs)to fabricate MMMs.The dipole–dipole interaction between C@ZnO and PIMs ensures their exceptional compatibility,mitigating the formation of non-selective voids in the resulting MMMs.Concurrently,C@ZnO with abundant interconnected pores can provide additional low-resistance pathways for gas transport in MMMs.As a result,the CO_(2) permeability of the optimized C@ZnO/PIM-1 MMMs is elevated to 13,215 barrer,while the CO_(2)/N_(2) and CO_(2)/CH_(4) selectivity reached 21.5 and 14.4,respectively,substantially surpassing the 2008 Robeson upper bound.Additionally,molecular simulation results further corroborate that the augmented membrane gas selectivity is attributed to the superior CO_(2) affinity of C@ZnO.In summary,we believe that this work not only expands the application of MMMs for gas separation but also heralds a paradigm shift in the application of porous carbon materials.
文摘Aim To define a mixed redundant model(MRM), improving the reliability of C 3I system. Methods The model combined the technology characters of two? unit system with one warm stand by unit and function substitute system. The reliability and availability equations of MRM were deduced. Results and Conclusion Compared with several other reliability models, it has obvious effect upon improving the system reliability. The effect? cost rate is very high among these models. The model can be used in reliability design, evaluation and check of C 3I system. Only a little attached cost is needed to improve C 3I system reliability effectively.
文摘With using the cone and partial ordering t heory and mixed monotone operator theory, the existence and uniqueness for solut ion of systems of non-monotone binary nonliear operator equations are discussed. And the iterative sequences which converge to solution of systems of operator e quations and the error estimates are also given. Some corresponding results for the mixed monotone operations and the unary operator equations are improved and generalized.
基金This work was supported by the National Natural Science Foundation of China(Nos.51904249 and 51922091)the Sichuan Science and Technology Program(No.SYZ202074)the Open Research Fund of State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization(No.CNMRCUKF2001).
文摘This paper researched the enhanced flotation separation performance of ilmenite and titanaugite using the mixed collector benzhydroxamic acid/dodecylamine(BHA/DDA).The interface assembly mechanism was mainly investigated through in situ attenuated total reflectance Fourier transform infrared(ATRFTIR)spectroscopy combined with the two-dimensional correlation spectroscopy(2D-COS)and X-ray photoelectron spectroscopy(XPS).It has been found that BHA/DDA mixed collectors successfully separate ilmenite from titanaugite at a molar ratio of 8:1.Zeta potential experiments suggested that,in the presence of mixed collector system,the BHA-DDA complex adsorbed on the ilmenite surface via the chemically adsorbed BHA and the electrostatically adsorbed DDA,however,the complex adsorbed on the surface of titanaugite unstably.According to in situ ATR-FTIR combined with 2D-COS and XPS results,the interface assembly mechanism of BHA/DDA is summarized as:the function group of BHA molecules first binds to the metal sites on minerals to form bidentate ligand,then DDA co-adsorbed with BHA on the surface of minerals through hydrogen bonding.DDA may change the adsorption modes of some BHA on the ilmenite surface from four-membered ring to five-membered ring,while the modes on the titanaugite surface is true opposite.Finally,recommended adsorption configurations of the BHA/DDA complex on the two mineral surfaces are proposed.
基金The support from the China National High Technology Research and Development Program(No.2013AA064301)the National Natural Science Foundation of China(51274210)the Research Start-up Fund of Karamay Campus of China University of Petroleum-Beijing(XQZX20200013)is greatly appreciated.
文摘A new temperature-resistant and salt-tolerant mixed surfactant system(referred to as the SS system)for enhancing oil recovery at the Tahe Oilfield(Xinjiang,China)was evaluated.Based on the analysis of the crude oil,the formation water and rock components in the Tahe Oilfield,the long-term thermal stability,salt tolerance and the ability to change the wettability,interfacial activity and oil washing efficiency of the mixed surfactant system were studied.The system contains the anionic surfactant SDB and another cationic surfactant SDY.When the total mass concentration of the SS solution is 0.15 wt%,m(SDB)/m(SDY)ratio is 1 to 1,and excellent efficiencies are achieved for oil washing for five kinds of Tahe Oilfield crude oils(more than 60%).In addition,after adding cationic surfactant,the adsorption capacity of the surfactant is further reduced,reaching 0.261 mg/g.The oil displacement experiments indicate that under a temperature of 150°C and a salinity of 24.6×104 mg/L,the SS system enhances the oil recovery by over 10%after water flooding.The SS anionic–cationic surfactant system is first presented in the open literature that can be successfully applied to obtain predictions of Tahe Oilfield carbonate reservoirs with a high temperature and high salinity.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10872165 and 10902085)
文摘This paper studies the phenomenon of stochastic resonance in an asymmetric bistable system with time-delayed feedback and mixed periodic signal by using the theory of signal-to-noise ratio in the adiabatic limit. A general approximate Fokker-Planck equation and the expression of the signal-to-noise ratio are derived through the small time delay approximation at both fundamental harmonics and mixed harmonics. The effects of the additive noise intensity Q, multiplicative noise intensity D, static asymmetry r and delay time T on the signal-to-noise ratio are discussed. It is found that the higher mixed harmonics and the static asymmetry r can restrain stochastic resonance, and the delay time τ can enhance stochastic resonance. Moreover, the longer the delay time τ is, the larger the additive noise intensity Q and the multiplicative noise intensity D are, when the stochastic resonance appears.
基金supported partly by the National Natural Science Foundation of China (Grant Nos.10764003 and 10947179)
文摘The interface phonon-polaritons in quantum well systems consisting of polar ternary mixed crystals are investi-gated. The numerical results of the interface phonon-polariton frequencies in the GaAs/AlxGa1-xAs, ZnSxSe1-x/ZnS, and ZnxCd1-xSe/ ZnSe quantum well systems are obtained and discussed. It is shown that there are six branches of interface phonon-polariton modes distributed in three bulk phonon-polariton forbidden bands in the systems. The electric fields of interface phonon polaritons are also presented and show the interface locality of the modes. The effects of the ＇two-mode＇ and ＇one-mode＇ behaviours of the ternary mixed crystals on the interface phonon-polariton modes are shown in the dispersion curves.
文摘This paper studies the nonlinear mixed problem for a class of symmetric hyperbolic systems with the boundary condition satisfying the dissipative condition about discontinuous data in higher dimension spaces, establishes the local existence theorem by using the method of a prior estimates, and obtains the structure of singularities of the solutions of such problems.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10905016 and 10971247)the Natural Science Foundation of Hebei Province of China (Grant Nos. A2012205062,A2012205013,and A2010000344)the Fund of Hebei Normal niversity
文摘We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state. For a composite system consisting of three cavities interacting with independent reservoirs, it is shown that the entanglement evolution is restricted by a set of monogamy relations. Furthermore, as quantified by the negativity, the entanglement dynamical property of the mixed entangled state of cavity photons is investigated. It is found that the three cavity photons can exhibit the phenomenon of entanglement sudden death （ESD）. However, compared with the evolution of a generalized three-qubit GHZ state which has the equal initial entanglement, the ESD time of mixed states is later than that of the pure state. Finally, we discuss the entanglement distribution in the multipartite system, and point out the intrinsic relation between the ESD of cavity photons and the entanglement sudden birth of reservoirs.
基金This study was supported by the National Key Research and Development Program of China(No.2018YFA0605601)Hong Kong Research Grants Council(No.106220169)+1 种基金the National Natural Science Foundation of China(Nos.41671042,42077417,42105155,and 42201083)the National Geographic Society(No.EC-95776R-22).
文摘Tree-ring chronologies were developed for Sabina saltuaria and Abies faxoniana in mixed forests in the Qionglai Mountains of the eastern Tibetan Plateau.Climate-growth relationship analysis indicated that the two co-exist-ing species reponded similarly to climate factors,although S.saltuaria was more sensitive than A.faxoniana.The strong-est correlation was between S.saltuaria chronology and regional mean temperatures from June to November.Based on this relationship,a regional mean temperature from June to November for the period 1605-2016 was constructed.Reconstruction explained 37.3%of the temperature variance during th period 1961-2016.Six major warm periods and five major cold periods were identified.Spectral analysis detected significant interannual and multi-decadal cycles.Reconstruction also revealed the influence of the Atlantic Multi-decadal Oscillation,confirming its importance on climate change on the eastern Tibetan Plateau.
基金Supported by the Natural Science Foundation of China under Grant Nos 11305114,11304226 and 11505126the Program for Innovative Research in University of Tianjin under Grant No TD13-5077
文摘Considering the influences of collective dephasing, multilocal qutrit-flip, local qutrit-flip, and the combination of global mixed noise, we study the dynamics of entanglement and the phenomenon of distillability of sudden death (DSD) in a qutrit-qutrit system under various decoherent noises. It is shown that the system always undergoes DSD when it interacts with multilocal and local qutrit-flip noise, and the time-determined bound entangled state is more dependent on different noises. Comparing with the cases of global mixed and collective dephasing noise,we conclude that the qutrit-flip noise is responsible for the DSD.
文摘The necessity,basis,characteristic and methods of restoring and reestabling broadleaved/coniferous mixed forest ecosystem from the secondary forest of Mongolian oak(Quercus mongolica)are briefly set forth;then several effective methods of restoration and reestablishment are put forward and discussed as follows:openning up effect belt or island to establish horizontal order mixture;replenishing the blank niche to make vertical orderly mix-ture;planting artificial mixed forest to create biological diversity;developing ecological forestry,establishing integrated agroforestry ecosystem;and closing the land for forest and pre-serving some stands considering special conditions and demads.
基金support from Sichuan Science and Technology Program(2021YFH0116)National Natural Science Foundation of China(No.52170112)DongFang Boiler Co.,Ltd.(3522015).
文摘Mixed matrix membranes(MMMs)could combine the advantages of both polymeric membranes and porousfillers,making them an effective alternative to conventional polymer membranes.However,interfacial incompatibility issues,such as the presence of interfacial voids,hardening of polymer chains,and blockage of micropores by polymers between common MMMsfillers and the polymer matrix,currently limit the gas sep-aration performance of MMMs.Ternary phase MMMs(consisting of afiller,an additive,and a matrix)made by adding a third compound,usually functionalized additives,can overcome the structural problems of binary phase MMMs and positively impact membrane separation performance.This review introduces the structure and fabrication processes for ternary MMMs,categorizes various nanofillers and the third component,and summarizes and analyzes in detail the CO_(2) separation performance of newly developed ternary MMMs based on both rubbery and glassy polymers.Based on this separation data,the challenges of ternary MMMs are also discussed.Finally,future directions for ternary MMMs are proposed.
基金supported by the National Natural Science Foundation of China(Grant No.61309005)the Basic and Frontier Research Program of Chongqing(Grant No.cstc2014jcyj A40015)
文摘Mixed redundancy strategies are generally used in cloud-based systems,with different node switch mechanisms from traditional fault-tolerant strategies.Existing studies often concentrate on optimizing a single strategy in cloud computing environment and ignore the impact of mixed redundancy strategies.Therefore,a model is proposed to evaluate and optimize the reliability and performance of cloud-based degraded systems subject to a mixed active and cold standby redundancy strategy.In this strategy,node switching is triggered by a continual monitoring and detection mechanism when active nodes fail.To evaluate the transient availability and the expected job completion rate of systems with such kind of strategy,a continuous-time Markov chain model is built on the state transition process and a numerical method is used to solve the model.To choose the optimal redundancy for the mixed strategy under system constraints,a greedy search algorithm is proposed after sensitivity analysis.Illustrative examples were presented to explain the process of calculating the transient probability of each system state and in turn,the availability and performance of the whole system.It was shown that the near-optimal redundancy solution could be obtained using the optimizationmethod.The comparison with optimization of the traditional mixed redundancy strategy proved that the system behavior was different using different kinds of mixed strategies and less redundancy was assigned for the new type of mixed strategy under the same system constraint.
基金Supported by the National Natural Science Foundation of China (60704002)
文摘The transient behaviors of traditional adaptive control may be very poor in general. A practically feasible approach to improve the transient performances is the adoption of adaptive switc- hing control. For a typical class of nonlinear systems disturbed by random noises, mixed multiple models consisting of adaptive model and fixed models were considered to design the switching con- trol law. Under certain assumptions, the nonlinear system with the switching control law was proved rigorously to be stable and optimal A simulation example was provided to compare the performance of the switching control and the traditional adaptive control.
文摘Magnetic hysteresis and compensation behavior of a mixed spin-（1, 3/2） Ising model on a square lattice are investigated in the framework of effective field theory based on a probability distribution technique. The effect of random crystal field, ferromagnetic and ferrimagnetic exchange interaction on hysteresis loops and compensation phenomenon are discussed. A number of characteristic phenomena have been reported such as the observation of triple hysteresis loops at low temperatures and for negative values of random crystal field. Critical and double compensation temperatures have been also found. The obtained results are also compared to some previous works.
基金supported by Capital Clinical Application Research Project(No.Z181100001718042)Cultivation and Enrichment of Front-Line Teachers,Battle Field Internal Medicine of Construction of Key Military Disciplines,13th Five Year Plan(No.A350109)。
文摘Deep vein thrombosis(DVT)is a manifestation of venous thromboembolism,which can result from long-term bed and lead to pulmonary embolism(PE),stroke,mesenteric artery embolis,etc.Patients after surgery without bed-off activity may prone to thrombosis,but traditional anticoagulant therapy is a contraindication for them because of high risk of postoperative hemorrhage.Inferior vena cava filter(IVCF)implantation is the most effective method to intercept thrombosis from lower limb and to prevent PE.However,radiation and contrast agent limit its application.Our team have successfully performed an IVCF implantation guided by a mixed-reality(MR)system,[1]which is a chance for critically ill patients to allow the IVCF implantation exposed under no Xray and require no contrast agent.5G can help remote holographic projection images between distant range,meeting the needs of experts to guide the operation of critically ill patients.We describe a case of weak woman after neurosurgery who can not tolerate traditional interventional surgery to prevent DVT from falling off.We performed a mixed-reality system guided IVCF implantation under remote guidance of 5G communication.
