The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of mana...The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.展开更多
Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development.Under high pressure conditions,small molecular components of natural gas dissolve into the polymer inner liner of the flexib...Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development.Under high pressure conditions,small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space,incurring annular pressure build-up and/or production of acidic environment,which poses serious challenges to the structure and integrity of the flexible pipes.Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature,annular structure,external temperature.In a long-distance gas flexible pipe,moreover,gas permeation exhibits non-uniform features,and the gas permeated into the annular space flows along the metal gap.To assess the complex gas transport behavior in long-distance gas flexible pipes,a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes,the diffusion of gas in the inner liner,and the gas seepage in the annular space under varying permeable properties of the annulus.In addition,the effect of a variable temperature is accounted.A numerical calculation method is accordingly constructed to solve the coupling mathematical equations.The annular permeability was shown to significantly influence the distribution of annular pressure.As permeability increases,the annular pressure tends to become more uniform,and the annular pressure at the wellhead rises more rapidly.After annular pressure relief followed by shut-in,the pressure increase follows a convex function.By simulating the pressure recovery pattern after pressure relief and comparing it with test results,we deduce that the annular permeability lies between 123 and 512 m D.The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.展开更多
As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crud...As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.展开更多
This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of ...This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of China toward European investment and trade,and in particular,has expanded with the continuous progress of the One Belt and One Road(OBOR)initiative.In addition to improving the service quality of CR Express,the operating costs must be reduced for developing“smart railways”that serve“smart cities”.We propose a dualobjective-based function mathematical optimization model;the satisfaction of the cargo owner is considered,and the timeliness,transportation capacity,and goods category constraints of CR Express transportation are designed.Moreover,we present the normalized equivalent method of the two-objective function of the model.Finally,a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study.展开更多
The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for...The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for hydrogen production.Despite remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle.This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment.To address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system.Compared to constant voltage electrolysis(hydrogen production rate:51.6 m L h^(-1),energy consumption:5.37 kWh Nm-^(3)H_(2)),this strategy(hydrogen production rate:66 m L h^(-1),energy consumption:3.83 kWh Nm-^(3)H_(2))increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic(PV)system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V.The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis(PDE)dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface.As such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport processes.This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.展开更多
Facilitated transport membranes for post-combustion carbon capture are one of the technologies to achieve efficient and large-scale capture.The central principle is to utilize the affinity of CO_(2) for the carrier to...Facilitated transport membranes for post-combustion carbon capture are one of the technologies to achieve efficient and large-scale capture.The central principle is to utilize the affinity of CO_(2) for the carrier to achieve efficient separation and to break the Robson upper bound.This paper reviews the progress of facilitated transport membranes research regarding polymer materials,principles,and problems faced at this stage.Firstly,we briefly introduce the transport mechanism of the facilitated transport membranes.Then the research progress of several major polymers used for facilitated transport membranes for CO_(2)/N_(2) separation was presented in the past five years.Additionally,we analyze the primary challenges of facilitated transport membranes,including the influence of water,the effect of temperature,the saturation effect of the carrier,and the process configuration.Finally,we also delve into the challenges and competitiveness of facilitated transport membranes.展开更多
(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport propert...(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport properties of(Mg,Fe)SiO_(3) with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa.We thoroughly examine the effects of pressure,temperature,and iron content on the bond lengths,coordination numbers,viscosities,and electrical conductivities of(Mg,Fe)SiO_(3).Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths,while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa,after which they are almost unchanged.The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa.The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of(Mg,Fe)SiO_(3).The increased temperatures slightly decrease the coordination numbers and viscosities,as well as obviously increase the diffusion coefficients and electrical conductivities of(Mg,Fe)SiO_(3).Additionally,iron doping facilitates the diffusion of Si and O,reduces the viscosities,and enhances the electrical conductivities of(Mg,Fe)SiO_(3).These findings advance fundamental understanding of the structural and transport properties of(Mg,Fe)SiO_(3) under high temperature and high pressure,which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.展开更多
This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer p...This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer patients.Our research reveals that phloretin inhibits typeⅡglucose transporter(GLUT2)activity,significantly reducing cancer cell glucose uptake.We confirmed the overexpression of GLUT1 and GLUT2 mRNA in paired human breast tumor tissues,with GLUT2 overexpression associated explicitly with poorer survival rates in breast cancer patients.Treatment with phloretin was observed to increase the interaction between GLUT2 and HER2 proteins,attenuate glycolysis,and enhance the binding affinity of anti-HER2 antibody drugs to target human breast cancer cells.Furthermore,the efficacy of the combination therapy involving phloretin and antibody drugs was reaffirmed in a cell-derived xenograft tumor animal model,particularly in suppressing the growth of trastuzumab-resistant HER2-positive(HER2+)breast cancer.These significant findings suggest that targeting GLUT2 activity with phloretin in combination with anti-HER2 antibody drugs may help mitigate the development of drug-resistant breast cancer,offering valuable insights for enhancing tumor treatment strategies and contributing to developing more effective therapies.展开更多
Transportation problem has many real world applications, it can be solved by linear programming model, but in most time the model exists more for less paradox, this paper considers the reasons for the paradox and s...Transportation problem has many real world applications, it can be solved by linear programming model, but in most time the model exists more for less paradox, this paper considers the reasons for the paradox and search the way to eliminate the phenomenon. First this paper formulates a loose constrained linear programming model for the transportation problem, and gives the definition of the paradox which exists in it, some preliminary notions and one example is also given. Then it gives a table based algorithm for the loose constrained model, the steps of the algorithm and example will follow. The examples show that: (1) It is not a contradictory that transportation problem exists more for less paradox. (2) The loose constrained model is better used in practice for its less total cost. (3) The algorithm is easy to calculate, to study and highly speed to convergence. Finally, comparied with other ways it shows that the loose constrained model can thoroughly eliminate the paradox.展开更多
Evacuated Tube Transport Technologies （ET3） offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to susta...Evacuated Tube Transport Technologies （ET3） offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to sustainably displace most global transportation by car, ship, truck, train, and jet aircraft. To do this, ET3 standards should adhere to certain key principals： maximum value through efficiency, reliability, and simplicity; equal consideration for passenger and cargo loads; optimum size; high speed/high frequency operation; demand oriented; random accessibility; scalability; high granularity; automated control; full speed passive switching; open standards of implementation; and maximum use of existing capacities, materials, and processes.展开更多
Evacuated tube transportation （ETT） will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT： （1） how to construct ultra-large-scale vacuum chamber ...Evacuated tube transportation （ETT） will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT： （1） how to construct ultra-large-scale vacuum chamber with lower cost and high reliability, （2） how to evacuate gas out of the ETT tube in short time, （3） how to release heat or reduce temperature in the vacuum tube, （4） how to avoid vacuum discharge, （5） how to make vehicles with airproof shells and life support system, and （6） how to detect leaks and find leak positions efficiently. At the same time, some solutions are proposed.展开更多
This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transporta...This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure （connected vehicles）. A major knowledge gap exists in AV technology with respect to routing behaviors. Connected- vehicle technology provides a great opportunity to imple- ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization literature on two fronts： （i） This study contributes to the it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and （ii） it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.展开更多
The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this...The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.展开更多
Based on the factors impact strength model(FISM), we studied on calculation formulas of influence strength and key elements of FISM, and analyzed the turnover time of railway freight transportation of China. The resul...Based on the factors impact strength model(FISM), we studied on calculation formulas of influence strength and key elements of FISM, and analyzed the turnover time of railway freight transportation of China. The results show that wagon transfer time is the most critical factor among the three subjective factors of wagons turnover time. The FISM based analysis of wagon transfer time show that the wagon turnover time is significantly correlated with transit time with resorting. Among the seven factors of detention time of transit time with resorting, the time of waiting to departing, converging, and waiting to break-up are key factors, while the time of make-up, break-up, arrival and departure are general factors. We carried out one empirical research based on the data of Baoji East Railway Station in 2015. The results of empirical research and FISM are consistent completely.展开更多
The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different fac...The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different factors on the aerodynamic drag of a train running at subsonic speed in an evacuated tube. Firstly, we present the assumption of a steady state, two dimensional, incompressible viscous flow with lubricity wall conditions. Subsequently, based on the Navier-Stokes equation and the k-c turbulent models, we calculate the aerodynamic drag imposed on the column train with a 3-meter diameter running under different pressure and blockage ratio conditions in an evacuated tube transporta- tion （ETT） system. The simulation is performed with FLUENT 6.3 software package. An analyses of the simulation re- sults suggest that the blockage ratio for ETT should be in the range of 0.25-0.7, and the tube internal diameter in the range of 2-4 m, with the feasible vacuum pressure in the range of 1-10 000 Pa for the future subsonic ETT trains.展开更多
Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmo- spheric turbulence over a long-distance uplink path are studied by numerical simulation. A linear coordinatio...Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmo- spheric turbulence over a long-distance uplink path are studied by numerical simulation. A linear coordination trans- formation is introduced to overcome the window effect and the loss-of-resolution problem. The beam spreading, beam wandering, and intensity scintillation as functions of turbulence strength, source correlation length, and change fre- quency of random phase that models the partial coherence of the source are analyzed. It is found that the beam spreading and the intensity scintillation of the partially coherent beam are less affected by the turbulence than those of the coherent one, but it suffers from a more severe diffractive effect, and the change frequency of random phase has no evident influence on it. The beam wandering is insensitive to the variation of source correlation length, and decreases firstly then goes to a fixed value as the change frequency increases.展开更多
This paper concerns the weak solutions of some Monge-Amp^re type equa- tions in the optimal transportation theory. The relationship between the Aleksandrov solutions and the viscosity solutions of the Monge-Ampere typ...This paper concerns the weak solutions of some Monge-Amp^re type equa- tions in the optimal transportation theory. The relationship between the Aleksandrov solutions and the viscosity solutions of the Monge-Ampere type equations is discussed. A uniform estimate for solution of the Dirichlet problem with homogeneous boundary value is obtained.展开更多
A novel structure of silicon-riched nitride(SRN)/silicon-riched oxide(SRO) is proposed and prepared using RF reactive magnetron co-sputtering. High temperature annealing of SRN/SRO multilayers leads to formation of Si...A novel structure of silicon-riched nitride(SRN)/silicon-riched oxide(SRO) is proposed and prepared using RF reactive magnetron co-sputtering. High temperature annealing of SRN/SRO multilayers leads to formation of Si nanocrystals(NC) from isolating SRN and SRO layers simultaneously, which efficiently improves carrier transport ability compared to conventional SRN/Si_3N_4 counterpart. Micro-Raman scattering analysis reveals that SRN layer has dominating number of denser and smaller Si NCs, while SRO layer has relatively less, sparser and bigger Si NCs, as confirmed by high resolution transmission electron microscopy observation. The substitute SRO layers for Si_3N_4 counterparts significantly increase the amount of Si NCs as well as crystallization ratio in SRN layers; while the average Si NC size can be well controlled by the thickness of SRN layers and the content of N, and hence an obvious stronger absorption in UV region for the novel structure can be observed in absorption spectra. The I-V characteristics show that the current of hybrid SRN/SRO system increases up to 2 orders of magnitude at 1 V and even 5 orders of magnitude at 4 V compared to that of SRN/Si_3N_4 structure. Si NCs in Si Oylayers provide a transport pathway for adjacent Si NCs in Si Nxlayers. The obvious advantage in carrier transportation suggests that SRN/SRO hybrid system could be a promising structure and platform to build Si nanostructured solar cells.展开更多
A methodology is proposed to evaluate and rank potential sites for facilities dealing with hazardous materials(HAZMAT).The proposed methodology incorporates HAZMAT route planning into facility siting while considering...A methodology is proposed to evaluate and rank potential sites for facilities dealing with hazardous materials(HAZMAT).The proposed methodology incorporates HAZMAT route planning into facility siting while considering transportation preferences and challenges.The area of interest is divided into smaller zones representing potential sites for a HAZMAT facility.A multimodal transportation network including railways and roads is considered for transportation of HAZMAT.Each zone is evaluated based on its accessibility from a set of selected points of interests(POIs),which are defined as potential origin/destination points for transportation of HAZMAT.The shortest routes between each POI and potential zones are evaluated based on a cost function which can accommodate multiple criteria to determine the associated disutility for each potential zone.Finally,zones are ranked based on their cumulative disutility scores.The proposed analysis method is quantitative,and at the same time it is adequately flexible to allow inclusion of subjective criteria.Application of the proposed methodology is demonstrated for identifying optimal locations for a HAZMAT facility(e.g.,a nuclear facility)using the Canadian province of Saskatchewan as an example.Three scenarios were evaluated including(1)all network segments and POIs were treated equally,(2)network segments were rank ordered based on their functional classification while POIs were treated equally and(3)network segments were rank ordered based on their functional classification with preferences given to specific POI(s).展开更多
in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6～35.6℃) and 10 km running (WBGT 25.0～31.1℃) were performed in laboratory and field under hot climate.Ten to twelve ...in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6～35.6℃) and 10 km running (WBGT 25.0～31.1℃) were performed in laboratory and field under hot climate.Ten to twelve times (days) of training were carried out展开更多
基金support of this work by National Key Research and Development Program of China(2019YFC19059003)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(23KJB430024)+1 种基金Jiangsu Funding Program for Excellent Postdoctoral Talent(2023ZB680)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)are gratefully acknowledged.
文摘The Janus fabrics designed for personal moisture/thermal regulation have garnered significant attention for their potential to enhance human comfort.However,the development of smart and dynamic fabrics capable of managing personal moisture/thermal comfort in response to changing external environments remains a challenge.Herein,a smart cellulose-based Janus fabric was designed to dynamically manage personal moisture/heat.The cotton fabric was grafted with N-isopropylacrylamide to construct a temperature-stimulated transport channel.Subsequently,hydrophobic ethyl cellulose and hydrophilic cellulose nanofiber were sprayed on the bottom and top sides of the fabric to obtain wettability gradient.The fabric exhibits anti-gravity directional liquid transportation from hydrophobic side to hydrophilic side,and can dynamically and continuously control the transportation time in a wide range of 3–66 s as the temperature increases from 10 to 40℃.This smart fabric can quickly dissipate heat at high temperatures,while at low temperatures,it can slow down the heat dissipation rate and prevent the human from becoming too cold.In addition,the fabric has UV shielding and photodynamic antibacterial properties through depositing graphitic carbon nitride nanosheets on the hydrophilic side.This smart fabric offers an innovative approach to maximizing personal comfort in environments with significant temperature variations.
基金supported by the Natural Science Research Project of Guangling College of Yangzhou University,China (ZKZD18004)General Program of Natural Science Research in Higher Education Institutions of Jiangsu Province,China (20KJD430006)。
文摘Gas flexible pipes are critical multi-layered equipment for offshore oil and gas development.Under high pressure conditions,small molecular components of natural gas dissolve into the polymer inner liner of the flexible pipes and further diffuse into the annular space,incurring annular pressure build-up and/or production of acidic environment,which poses serious challenges to the structure and integrity of the flexible pipes.Gas permeation in pipes is a complex phenomenon governed by various factors such as internal pressure and temperature,annular structure,external temperature.In a long-distance gas flexible pipe,moreover,gas permeation exhibits non-uniform features,and the gas permeated into the annular space flows along the metal gap.To assess the complex gas transport behavior in long-distance gas flexible pipes,a mathematical model is established in this paper considering the multiphase flow phenomena inside the flexible pipes,the diffusion of gas in the inner liner,and the gas seepage in the annular space under varying permeable properties of the annulus.In addition,the effect of a variable temperature is accounted.A numerical calculation method is accordingly constructed to solve the coupling mathematical equations.The annular permeability was shown to significantly influence the distribution of annular pressure.As permeability increases,the annular pressure tends to become more uniform,and the annular pressure at the wellhead rises more rapidly.After annular pressure relief followed by shut-in,the pressure increase follows a convex function.By simulating the pressure recovery pattern after pressure relief and comparing it with test results,we deduce that the annular permeability lies between 123 and 512 m D.The results help shed light upon assessing the annular pressure in long distance gas flexible pipes and thus ensure the security of gas transport in the emerging development of offshore resources.
基金This work was financially supported by the National Natural Science Foundation of China(52074089 and 52104064)Natural Science Foundation of Heilongjiang Province of China(LH2019E019).
文摘As the main link of ground engineering,crude oil gathering and transportation systems require huge energy consumption and complex structures.It is necessary to establish an energy efficiency evaluation system for crude oil gathering and transportation systems and identify the energy efficiency gaps.In this paper,the energy efficiency evaluation system of the crude oil gathering and transportation system in an oilfield in western China is established.Combined with the big data analysis method,the GA-BP neural network is used to establish the energy efficiency index prediction model for crude oil gathering and transportation systems.The comprehensive energy consumption,gas consumption,power consumption,energy utilization rate,heat utilization rate,and power utilization rate of crude oil gathering and transportation systems are predicted.Considering the efficiency and unit consumption index of the crude oil gathering and transportation system,the energy efficiency evaluation system of the crude oil gathering and transportation system is established based on a game theory combined weighting method and TOPSIS evaluation method,and the subjective weight is determined by the triangular fuzzy analytic hierarchy process.The entropy weight method determines the objective weight,and the combined weight of game theory combines subjectivity with objectivity to comprehensively evaluate the comprehensive energy efficiency of crude oil gathering and transportation systems and their subsystems.Finally,the weak links in energy utilization are identified,and energy conservation and consumption reduction are improved.The above research provides technical support for the green,efficient and intelligent development of crude oil gathering and transportation systems.
基金supported by the National Natural Science Foundation of China(Grant No.62102032)the R&D Program of Beijing Municipal Education Commission(Grant No.KM202211417010).
文摘This paper describes the development and optimization plans for the China Railway Express(CR Express).As a new type of international land transport organization,CR Express has emerged with the continuous expansion of China toward European investment and trade,and in particular,has expanded with the continuous progress of the One Belt and One Road(OBOR)initiative.In addition to improving the service quality of CR Express,the operating costs must be reduced for developing“smart railways”that serve“smart cities”.We propose a dualobjective-based function mathematical optimization model;the satisfaction of the cargo owner is considered,and the timeliness,transportation capacity,and goods category constraints of CR Express transportation are designed.Moreover,we present the normalized equivalent method of the two-objective function of the model.Finally,a case study is conducted against the background of certain trains in the western corridor of CR Express to validate the effectiveness of the model and research methods proposed in this study.
基金National Natural Science Foundation of China(No.52476192,No.52106237)Natural Science Foundation of Heilongjiang Province(No.YQ2022E027)。
文摘The transition of hydrogen sourcing from carbon-intensive to water-based methodologies is underway,with renewable energy-powered proton exchange membrane water electrolysis(PEMWE)emerging as the preeminent pathway for hydrogen production.Despite remarkable advancements in this field,confronting the sluggish electrochemical kinetics and inherent high-energy consumption arising from deteriorated mass transport within PEMWE systems remains a formidable obstacle.This impediment stems primarily from the hindered protons mass transfer and the untimely hydrogen bubbles detachment.To address these challenges,we harness the inherent variability of electrical energy and introduce an innovative pulsed dynamic water electrolysis system.Compared to constant voltage electrolysis(hydrogen production rate:51.6 m L h^(-1),energy consumption:5.37 kWh Nm-^(3)H_(2)),this strategy(hydrogen production rate:66 m L h^(-1),energy consumption:3.83 kWh Nm-^(3)H_(2))increases the hydrogen production rate by approximately 27%and reduces the energy consumption by about 28%.Furthermore,we demonstrate the practicality of this system by integrating it with an off-grid photovoltaic(PV)system designed for outdoor operation,successfully driving a hydrogen production current of up to 500 mA under an average voltage of approximately 2 V.The combined results of in-situ characterization and finite element analysis reveal the performance enhancement mechanism:pulsed dynamic electrolysis(PDE)dramatically accelerates the enrichment of protons at the electrode/solution interface and facilitates the release of bubbles on the electrode surface.As such,PDE-enhanced PEMWE represents a synergistic advancement,concurrently enhancing both the hydrogen generation reaction and associated transport processes.This promising technology not only redefines the landscape of electrolysis-based hydrogen production but also holds immense potential for broadening its application across a diverse spectrum of electrocatalytic endeavors.
文摘Facilitated transport membranes for post-combustion carbon capture are one of the technologies to achieve efficient and large-scale capture.The central principle is to utilize the affinity of CO_(2) for the carrier to achieve efficient separation and to break the Robson upper bound.This paper reviews the progress of facilitated transport membranes research regarding polymer materials,principles,and problems faced at this stage.Firstly,we briefly introduce the transport mechanism of the facilitated transport membranes.Then the research progress of several major polymers used for facilitated transport membranes for CO_(2)/N_(2) separation was presented in the past five years.Additionally,we analyze the primary challenges of facilitated transport membranes,including the influence of water,the effect of temperature,the saturation effect of the carrier,and the process configuration.Finally,we also delve into the challenges and competitiveness of facilitated transport membranes.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12174352 and 12111530103)the Fundamental Research Funds for the Central Universities,China University of Geosciences(Wuhan)(Grant No.G1323523065)。
文摘(Mg,Fe)SiO_(3) is primarily located in the mantle and has a substantial impact on geophysical and geochemical processes.Here,we employ molecular dynamics simulations to investigate the structural and transport properties of(Mg,Fe)SiO_(3) with varying iron contents at temperatures up to 5000 K and pressures up to 135 GPa.We thoroughly examine the effects of pressure,temperature,and iron content on the bond lengths,coordination numbers,viscosities,and electrical conductivities of(Mg,Fe)SiO_(3).Our calculations indicate that the increase of pressure leads to the shortening of the O-O and Mg-O bond lengths,while the Si-O bond lengths exhibit the initial increase with pressure up to 40 GPa,after which they are almost unchanged.The coordination numbers of Si transition from four-fold to six-fold and eventually reach eight-fold coordination at 135 GPa.The enhanced pressure causes the decrease of the diffusion coefficients and the increase of the viscosities of(Mg,Fe)SiO_(3).The increased temperatures slightly decrease the coordination numbers and viscosities,as well as obviously increase the diffusion coefficients and electrical conductivities of(Mg,Fe)SiO_(3).Additionally,iron doping facilitates the diffusion of Si and O,reduces the viscosities,and enhances the electrical conductivities of(Mg,Fe)SiO_(3).These findings advance fundamental understanding of the structural and transport properties of(Mg,Fe)SiO_(3) under high temperature and high pressure,which provide novel insights for unraveling the complexities of geological processes within the Earth's mantle.
基金supported by the Science and Technology Council,Taiwan,China(NSTC 112-2320-B-039-057 and MOST 111-2320-B-039-067-MY3)the China Medical University,Taiwan,China(CMU112-S-18),awarded to Yuan-Soon Ho+1 种基金the China Medical University,Taiwan,China(CMU112-N-02),awarded to Li-Ching Chenthe Science and Technology Council,Taiwan,China(MOST 110-2320B-039-079)。
文摘This study presents novel findings on the potential of phloretin,an apple polyphenol,to enhance the effectiveness of anti-human epidermal growth factor receptor-2(HER2)antibody therapy in HER2-positive breast cancer patients.Our research reveals that phloretin inhibits typeⅡglucose transporter(GLUT2)activity,significantly reducing cancer cell glucose uptake.We confirmed the overexpression of GLUT1 and GLUT2 mRNA in paired human breast tumor tissues,with GLUT2 overexpression associated explicitly with poorer survival rates in breast cancer patients.Treatment with phloretin was observed to increase the interaction between GLUT2 and HER2 proteins,attenuate glycolysis,and enhance the binding affinity of anti-HER2 antibody drugs to target human breast cancer cells.Furthermore,the efficacy of the combination therapy involving phloretin and antibody drugs was reaffirmed in a cell-derived xenograft tumor animal model,particularly in suppressing the growth of trastuzumab-resistant HER2-positive(HER2+)breast cancer.These significant findings suggest that targeting GLUT2 activity with phloretin in combination with anti-HER2 antibody drugs may help mitigate the development of drug-resistant breast cancer,offering valuable insights for enhancing tumor treatment strategies and contributing to developing more effective therapies.
文摘Transportation problem has many real world applications, it can be solved by linear programming model, but in most time the model exists more for less paradox, this paper considers the reasons for the paradox and search the way to eliminate the phenomenon. First this paper formulates a loose constrained linear programming model for the transportation problem, and gives the definition of the paradox which exists in it, some preliminary notions and one example is also given. Then it gives a table based algorithm for the loose constrained model, the steps of the algorithm and example will follow. The examples show that: (1) It is not a contradictory that transportation problem exists more for less paradox. (2) The loose constrained model is better used in practice for its less total cost. (3) The algorithm is easy to calculate, to study and highly speed to convergence. Finally, comparied with other ways it shows that the loose constrained model can thoroughly eliminate the paradox.
文摘Evacuated Tube Transport Technologies （ET3） offers the potential for more than an order of magnitude improvement in transportation efficiency, speed, cost, and effectiveness. An ET3 network may be optimized to sustainably displace most global transportation by car, ship, truck, train, and jet aircraft. To do this, ET3 standards should adhere to certain key principals： maximum value through efficiency, reliability, and simplicity; equal consideration for passenger and cargo loads; optimum size; high speed/high frequency operation; demand oriented; random accessibility; scalability; high granularity; automated control; full speed passive switching; open standards of implementation; and maximum use of existing capacities, materials, and processes.
基金provided by National Natural Science Foundation of China (No.50678152)Scientific Plan Fund of Shaanxi Province (No.2009K09-24)
文摘Evacuated tube transportation （ETT） will be one of the ultra-large-scale vacuum application areas. This paper lists some key vacuum technology issues in ETT： （1） how to construct ultra-large-scale vacuum chamber with lower cost and high reliability, （2） how to evacuate gas out of the ETT tube in short time, （3） how to release heat or reduce temperature in the vacuum tube, （4） how to avoid vacuum discharge, （5） how to make vehicles with airproof shells and life support system, and （6） how to detect leaks and find leak positions efficiently. At the same time, some solutions are proposed.
文摘This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure （connected vehicles）. A major knowledge gap exists in AV technology with respect to routing behaviors. Connected- vehicle technology provides a great opportunity to imple- ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization literature on two fronts： （i） This study contributes to the it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and （ii） it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.
基金the Indian Institute of Technology (Indian School of Mines), Dhanbad for providing necessary laboratory facilities and financial support
文摘The most economical way to overcome flow assurance problems associated with transportation of heavy crude oil through offshore pipelines is by emulsifying it with water in the presence of a suitable surfactant.In this research,a novel surfactant,tri-triethanolamine monosunflower ester,was synthesized in the laboratory by extracting fatty acids present in sunflower（Helianthus annuus）oil.Synthesized surfactant was used to prepare oil-in-water emulsions of a heavy crude oil from the western oil field of India.After emulsification,a dramatic decrease in pour point as well as viscosity was observed.All the prepared emulsions were found to be flowing even at 1°C.The emulsion developed with 60%oil content and 2wt%surfactant showed a decrease in viscosity of 96%.The stability of the emulsion was investigated at different temperatures,and it was found to be highly stable.The effectiveness of surfactant in emulsifying the heavy oil in water was investigated by measuring the equilibrium interfacial tension（IFT）between the crude oil（diluted）and the aqueous phase along with zeta potential of emulsions.2wt%surfactant decreased IFT by almost nine times that of no surfactant.These results suggested that the synthesized surfactant may be used to prepare a stable oil-in-water emulsion for its transportation through offshore pipelines efficiently.
基金Funded by the Fundamental Research Funds for the Central Universities of China(No.26816WTD23)the National United Engineering Laboratory of Integrated and Intelligent Transportation of Southwest Jiaotong University,P.R.China(No.2682017ZT11)
文摘Based on the factors impact strength model(FISM), we studied on calculation formulas of influence strength and key elements of FISM, and analyzed the turnover time of railway freight transportation of China. The results show that wagon transfer time is the most critical factor among the three subjective factors of wagons turnover time. The FISM based analysis of wagon transfer time show that the wagon turnover time is significantly correlated with transit time with resorting. Among the seven factors of detention time of transit time with resorting, the time of waiting to departing, converging, and waiting to break-up are key factors, while the time of make-up, break-up, arrival and departure are general factors. We carried out one empirical research based on the data of Baoji East Railway Station in 2015. The results of empirical research and FISM are consistent completely.
基金supported by the National Natural Science Foundation of China (No. 50678152)the Scientific Plan Fund of Shaanxi Province(No. 2009K09-24)
文摘The aerodynamic drag on a train running in an evacuated tube varies with tube air pressure, train speed and shape, as well as blockage ratio. This paper uses numerical simulations to study the effects of different factors on the aerodynamic drag of a train running at subsonic speed in an evacuated tube. Firstly, we present the assumption of a steady state, two dimensional, incompressible viscous flow with lubricity wall conditions. Subsequently, based on the Navier-Stokes equation and the k-c turbulent models, we calculate the aerodynamic drag imposed on the column train with a 3-meter diameter running under different pressure and blockage ratio conditions in an evacuated tube transporta- tion （ETT） system. The simulation is performed with FLUENT 6.3 software package. An analyses of the simulation re- sults suggest that the blockage ratio for ETT should be in the range of 0.25-0.7, and the tube internal diameter in the range of 2-4 m, with the feasible vacuum pressure in the range of 1-10 000 Pa for the future subsonic ETT trains.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 61107066 and 40805006)
文摘Propagation properties of spatially pseudo-partially coherent Gaussian Schell-model beams through the atmo- spheric turbulence over a long-distance uplink path are studied by numerical simulation. A linear coordination trans- formation is introduced to overcome the window effect and the loss-of-resolution problem. The beam spreading, beam wandering, and intensity scintillation as functions of turbulence strength, source correlation length, and change fre- quency of random phase that models the partial coherence of the source are analyzed. It is found that the beam spreading and the intensity scintillation of the partially coherent beam are less affected by the turbulence than those of the coherent one, but it suffers from a more severe diffractive effect, and the change frequency of random phase has no evident influence on it. The beam wandering is insensitive to the variation of source correlation length, and decreases firstly then goes to a fixed value as the change frequency increases.
基金supported by National Natural Science Foundation of China(11071119)
文摘This paper concerns the weak solutions of some Monge-Amp^re type equa- tions in the optimal transportation theory. The relationship between the Aleksandrov solutions and the viscosity solutions of the Monge-Ampere type equations is discussed. A uniform estimate for solution of the Dirichlet problem with homogeneous boundary value is obtained.
基金supported by the National Natural Science Foundation of China(No.61036001,51072194and 60906035)
文摘A novel structure of silicon-riched nitride(SRN)/silicon-riched oxide(SRO) is proposed and prepared using RF reactive magnetron co-sputtering. High temperature annealing of SRN/SRO multilayers leads to formation of Si nanocrystals(NC) from isolating SRN and SRO layers simultaneously, which efficiently improves carrier transport ability compared to conventional SRN/Si_3N_4 counterpart. Micro-Raman scattering analysis reveals that SRN layer has dominating number of denser and smaller Si NCs, while SRO layer has relatively less, sparser and bigger Si NCs, as confirmed by high resolution transmission electron microscopy observation. The substitute SRO layers for Si_3N_4 counterparts significantly increase the amount of Si NCs as well as crystallization ratio in SRN layers; while the average Si NC size can be well controlled by the thickness of SRN layers and the content of N, and hence an obvious stronger absorption in UV region for the novel structure can be observed in absorption spectra. The I-V characteristics show that the current of hybrid SRN/SRO system increases up to 2 orders of magnitude at 1 V and even 5 orders of magnitude at 4 V compared to that of SRN/Si_3N_4 structure. Si NCs in Si Oylayers provide a transport pathway for adjacent Si NCs in Si Nxlayers. The obvious advantage in carrier transportation suggests that SRN/SRO hybrid system could be a promising structure and platform to build Si nanostructured solar cells.
基金supported by Sylvia Fedoruk Canadian Centre for Nuclear Innovation
文摘A methodology is proposed to evaluate and rank potential sites for facilities dealing with hazardous materials(HAZMAT).The proposed methodology incorporates HAZMAT route planning into facility siting while considering transportation preferences and challenges.The area of interest is divided into smaller zones representing potential sites for a HAZMAT facility.A multimodal transportation network including railways and roads is considered for transportation of HAZMAT.Each zone is evaluated based on its accessibility from a set of selected points of interests(POIs),which are defined as potential origin/destination points for transportation of HAZMAT.The shortest routes between each POI and potential zones are evaluated based on a cost function which can accommodate multiple criteria to determine the associated disutility for each potential zone.Finally,zones are ranked based on their cumulative disutility scores.The proposed analysis method is quantitative,and at the same time it is adequately flexible to allow inclusion of subjective criteria.Application of the proposed methodology is demonstrated for identifying optimal locations for a HAZMAT facility(e.g.,a nuclear facility)using the Canadian province of Saskatchewan as an example.Three scenarios were evaluated including(1)all network segments and POIs were treated equally,(2)network segments were rank ordered based on their functional classification while POIs were treated equally and(3)network segments were rank ordered based on their functional classification with preferences given to specific POI(s).
文摘in order to verify the heat-tolerance effect, two trainings, 90 min marching with load (WBGT 24. 6～35.6℃) and 10 km running (WBGT 25.0～31.1℃) were performed in laboratory and field under hot climate.Ten to twelve times (days) of training were carried out
