The modernization of the Traditional East Medicine industry has increasingly emphasized the role of collaborative innovation across the entire industrial chain.This paper investigates the mechanisms by which experts i...The modernization of the Traditional East Medicine industry has increasingly emphasized the role of collaborative innovation across the entire industrial chain.This paper investigates the mechanisms by which experts in cultivation,processing,R&D,production,and clinical application interact to enhance overall efficiency.By analyzing the bottlenecks in resource allocation,knowledge integration,and institutional design,the study proposes a comprehensive framework of collaborative mechanisms.The results highlight that multi-dimensional collaboration not only improves innovation efficiency but also accelerates the translation of scientific research into industrial outcomes.The findings provide theoretical support and practical implications for improving the synergy of experts in the Traditional East Medicine industry and contribute to the sustainable development of traditional medicine under modern industrial demands.展开更多
The multi-mode integrated railway system,anchored by the high-speed railway,caters to the diverse travel requirements both within and between cities,offering safe,comfortable,punctual,and eco-friendly transportation s...The multi-mode integrated railway system,anchored by the high-speed railway,caters to the diverse travel requirements both within and between cities,offering safe,comfortable,punctual,and eco-friendly transportation services.With the expansion of the railway networks,enhancing the efficiency and safety of the comprehensive system has become a crucial issue in the advanced development of railway transportation.In light of the prevailing application of artificial intelligence technologies within railway systems,this study leverages large model technology characterized by robust learning capabilities,efficient associative abilities,and linkage analysis to propose an Artificial-intelligent(AI)-powered railway control and dispatching system.This system is elaborately designed with four core functions,including global optimum unattended dispatching,synergetic transportation in multiple modes,high-speed automatic control,and precise maintenance decision and execution.The deployment pathway and essential tasks of the system are further delineated,alongside the challenges and obstacles encountered.The AI-powered system promises a significant enhancement in the operational efficiency and safety of the composite railway system,ensuring a more effective alignment between transportation services and passenger demands.展开更多
Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets it...Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets itself apart from existing research by applying a novel optimization technique to a basic ideal Rankine cycle,focusing on a specific power plant that has not been previously analyzed.Currently,this cycle operates at 41%efficiency and a steam quality of 76%,constrained by fixed operational parameters.The primary objectives are to increase thermal efficiency beyond 46%and raise steam quality above 85%,while adhering to operational limits:a boiler pressure not exceeding 15 MPa,condenser pressure not dropping below 10 kPa,and turbine temperature not surpassing 500℃.This study utilizes numerical simulations to model the effects of varying boiler pressure(Pb)and condenser pressure(Pc)within the ranges of 12MPa<Pb<15 MPa and 5 kPa<Pc<10 kPa.By systematically adjusting these parameters,the proposed aimto identify optimal conditions that maximize efficiency and performance within specified constraints.The findings will provide valuable insights for power plant operators seeking to optimize performance under real-world conditions,contributing to more efficient and sustainable power generation.展开更多
For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmissi...For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.展开更多
PEM （Proton Exchange Membrane） fuel cell is a promising renewable energy source to a wide range of applications for its clean products and high power density. However, controlling its humidity is a challenging probl...PEM （Proton Exchange Membrane） fuel cell is a promising renewable energy source to a wide range of applications for its clean products and high power density. However, controlling its humidity is a challenging problem due to the interdependence of several phenomena contributing in membrane＇s water content. This work deals with efficiency improvement of PEM fuel cells via humidity control. An innovative strategy of control based on the model of Ref. [1] is proposed. It consists on regulating gas humidification rates according to the power demand so that to minimize power losses. The proposed control takes into consideration constraints related to humidification in order to avoid dry out or flooding of the membrane. Simulations results show that time-phasing between hydrogen and oxygen humidification rates plays an important role in minimizing power losses. The proposed control shows significant improvement in the fuel cell＇s efficiency up to 20%.展开更多
In mammalians, the state of a somatic cell can be reversed from the terminal state to the totipotent state by means of somatic cell nuclear transfer （SCNT） （Gurdon, 1962） or induced pluripotent stem cells （iPSCs...In mammalians, the state of a somatic cell can be reversed from the terminal state to the totipotent state by means of somatic cell nuclear transfer （SCNT） （Gurdon, 1962） or induced pluripotent stem cells （iPSCs） （Takahashi and Yamanaka, 2006）. The DNA methylation and transcriptome profiles of embryonic stern cells （ESCs） derived from SCNT embryos （NT-ESCs） correspond closely to those of ESCs derived from in vitro fertilization embryos （IVF- ESCs）. In contrast, iPSCs differ from both NT-ESCs and IVF-ESCs in that they retain the residual DNA methylation patterns of their parental somatic cells. As SCNT can be used to faithfully reprogram human somatic cells to pluripotency, it is ideal for cell replacement therapies （Ma et al., 2014）. Following the successful production of the first human NT-ESCs （Tachibana et al., 2013） and the later gen- eration of human NT-ESCs based on cells from elderly adults or pa- tient cells （Chung et al., 2014; Yamada et al., 2014）, a version of the SCNT technique for human therapeutics comes closer to reality. However, no matter what animal species or donor cell types are used in the cloned process, the cloning efficiency remains undesir- able. Besides, there are many phenotypic abnormalities in cloned animals, containing frequent embryonic and perinatal death and placentomegaly, and the underlying mechanisms remain unclear （Yang et al, 2007）.展开更多
In my country, most of the mines are located in an area with a complex geological environment. Therefore, the mining and measurement of the mines are difficult and dangerous. Since the quality and efficiency of the mi...In my country, most of the mines are located in an area with a complex geological environment. Therefore, the mining and measurement of the mines are difficult and dangerous. Since the quality and efficiency of the mine are directly affected by the mine survey work during the mining process, the mining unit should pay attention to the development process of the mine survey work and to improve the efficiency of the mine survey work. At this stage, compared with the mine measurement technology of developed countries, my country's mine measurement technology still has a certain gap and a lot of room for improvement, and it is impossible to accurately guarantee the validity and standardization of mine measurement. Based on this, this paper explores how to improve the efficiency of mine surveying, aiming to provide some valuable references for mine surveying.展开更多
The conventional P ＆ O （perturb-and-observe） method, which is the most widely used as MPPT （maximum power point tracking） control, has the problem of low efficiency and unstable operation when solar radiation cha...The conventional P ＆ O （perturb-and-observe） method, which is the most widely used as MPPT （maximum power point tracking） control, has the problem of low efficiency and unstable operation when solar radiation changes drastically. Aiming at this problem, this paper improves the conventional P ＆ O method to reduce the bad effect of solar radiation by shortening the sampling interval of PV module＇s output power while keeping the operating period unchanged. Experiments are conducted to study efficiency gains of improved method when solar radiation changes drastically. The result shows that, by this method, the efficiency of MPPT control can be increased 17% in average when PV module simulator is used and 20% at maximum when actual PV module is used, compared with the conventional P ＆ O method.展开更多
In the high school mathematics classroom under the background of new curriculum reform, students are the main body of teaching, which is different from traditional teaching. Teachers need to clearly realize the signif...In the high school mathematics classroom under the background of new curriculum reform, students are the main body of teaching, which is different from traditional teaching. Teachers need to clearly realize the significance of students' main body status, pay attention to students' subjectivity in the classroom, and promote quality education from the perspective of students. In senior high school, students' learning background, learning style and character are quite different, so they are quite different when analyzing typical problems. In high school mathematics teaching, this kind of personalized difference will also affect students' learning ability. In this regard, teachers should start from the perspective of students' subject, pay attention to the differences of students, and create an efficient mathematics classroom. Under the new situation, to develop high school mathematics teaching well, only by exploring teaching problems from a new perspective and establishing new teaching concepts can the rapid development of mathematics teaching reform be promoted. Below, the article puts forward some suggestions on strategies to improve the efficiency of high school mathematics classroom teaching under the background of the new curriculum.展开更多
SPECIAL|Eyes on Academic Publishing in AI Era At a time when artificial intelligence(AI)is permeating many aspects of human life,academic publishing is faced with new challenges:How should academic journals safeguard ...SPECIAL|Eyes on Academic Publishing in AI Era At a time when artificial intelligence(AI)is permeating many aspects of human life,academic publishing is faced with new challenges:How should academic journals safeguard scholarly quality and research integrity against AI misuse?How should we improve efficiency with the aid of AI?展开更多
Computer analysis of electrocardiograms(ECGs)was introduced more than 50 years ago,with the aim to improve efficiency and clinical workflow.[1,2]However,inaccuracies have been documented in the literature.[3,4]Researc...Computer analysis of electrocardiograms(ECGs)was introduced more than 50 years ago,with the aim to improve efficiency and clinical workflow.[1,2]However,inaccuracies have been documented in the literature.[3,4]Research indicates that emergency department(ED)clinician interruptions occur every 4-10 min,which is significantly more common than in other specialties.[5]This increases the cognitive load and error rates and impacts patient care and clinical effi ciency.[1,2,5]De-prioritization protocols have been introduced in certain centers in the United Kingdom(UK),removing the need for clinician ECG interpretation where ECGs have been interpreted as normal by the machine.展开更多
We applied water releasing from rootstocks technique and Juglans sigillata in Yangbi was pruned in the shape of opened-heart or round-heart shape. By bal- anced fertilization, survival rate of grafted walnuts can be i...We applied water releasing from rootstocks technique and Juglans sigillata in Yangbi was pruned in the shape of opened-heart or round-heart shape. By bal- anced fertilization, survival rate of grafted walnuts can be improved. We reviewed technologies to enhance walnut quality and production efficiency in Gongshan Derung and Nu Autonomous County for reference.展开更多
With the rapid development of artificial intelligence technology,AIGC(Artificial Intelligence-Generated Content)has triggered profound changes in the field of high-level language programming courses.This paper deeply ...With the rapid development of artificial intelligence technology,AIGC(Artificial Intelligence-Generated Content)has triggered profound changes in the field of high-level language programming courses.This paper deeply explored the application principles,advantages,and limitations of AIGC in intelligent code generation,analyzed the new mode of human-computer collaboration in high-level language programming courses driven by AIGC,discussed the impact of human-computer collaboration on programming efficiency and code quality through practical case studies,and looks forward to future development trends.This research aims to provide theoretical and practical guidance for high-level language programming courses and promote innovative development of high-level language programming courses under the human-computer collaboration paradigm.展开更多
Hydrodynamic cavitation,as an efficient technique applied in many physical and chemical treatment methods,has been widely used by various industries and in several technological fields.Relevant generators,designed wit...Hydrodynamic cavitation,as an efficient technique applied in many physical and chemical treatment methods,has been widely used by various industries and in several technological fields.Relevant generators,designed with specific structures and parameters,can produce cavitation effects,thereby enabling effective treatment and reasonable transformation of substances.This paper reviews the design principles,performance,and practical applications associated with different types of cavitation generators,aiming to provide theoretical support for the optimization of these systems.It systematically analyzes the underpinning mechanisms and the various factors influencing the cavitation phenomena,also conducting a comparative analysis of the performance of different types of generators.Specific applications dealing with wastewater treatment,chemical reaction acceleration,and other fields are discussed together with the advantages,disadvantages,and applicability of each type of cavitation generator.We also explore research progress in areas such as cavitation stability,energy efficiency,and equipment design upgrades.The study concludes by forecasting the application prospects of intelligent design and computational fluid dynamics(CFD)in optimizing and advancing cavitation generators.It proposes new ideas for the further development of cavitation technology and highlights directions for its widespread future application.展开更多
In this paper,different stands in Xianzhong Nursery of Pingjiang were selected as the research object to study the runoff generation and soil loss characteristics of different stands.The results showed that the annual...In this paper,different stands in Xianzhong Nursery of Pingjiang were selected as the research object to study the runoff generation and soil loss characteristics of different stands.The results showed that the annual surface runoff of each model in Pingjiang was between 50.50 and 70.38 mm,and the annual surface runoff of each stand decreased with years.There was no significant difference in the annual runoff between each stand,nor between each stand and its control.There were significant differences in soil erosion modulus among the models,and the number ranged from 139.20 to 197.79 t/(km^(2)·y).展开更多
Parabolic trough collector is a promising technology for both domestic and industrial heat supplies.To enhance the collector efficiency,a modified trough receiver with dozens of V-grooved light traps incorporated into...Parabolic trough collector is a promising technology for both domestic and industrial heat supplies.To enhance the collector efficiency,a modified trough receiver with dozens of V-grooved light traps incorporated into its lower-half absorber was introduced.For assessing the performance of this receiver,a solar-thermal-stress coupled model was established.Using this model,firstly,the effects of the V-grooved light traps were investigated.The results reveal that,compared to the conventional trough receiver,the modified trough receivers equipped with different traps can reduce their optical losses by 81.9-138.0 Wm^(-1)(i.e.,15.0%-25.2%),improving their optical efficiencies by 1.60%-2.69%.However,these traps also result in increased thermal loss from the receiver.Therefore,there is no single optimal modified trough receiver that consistently outperforms all other receivers across all possible conditions.Nonetheless,the MTR30-3 and MTR60-3 receivers emerge as the optimized choices due to their better solar-thermal performance.Subsequently,performance evaluation reveals that the two optimized receivers can enhance the receiver efficiencies within the typical solar irradiance range by 0.02%-2.65%and 0.05%-1.70%when the inlet fluid temperatures are below 488 and 523 K,respectively.Consequently,the collector efficiencies can be improved by 0.02%-2.49%and 0.05%-1.60%,respectively.Additionally,thermal stress analysis verifies that the two optimized receivers remain within safe limits under all typical conditions.Given that the heating temperature of a typical solar collector for domestic or industrial heat supply is typically below 523 K,the integration of the two optimized receivers has the capability to effectively enhance the overall collector efficiency.展开更多
Proppant flowback in the post-fracturing flowback period not only reduces the fracture conductivity but also damages equipment.Due to the current lack of experimental or numerical simulation methods for proppant flowb...Proppant flowback in the post-fracturing flowback period not only reduces the fracture conductivity but also damages equipment.Due to the current lack of experimental or numerical simulation methods for proppant flowback in partial closure fracture,the mechanisms and patterns of proppant flowback remain unclear.This makes it difficult to predict the risks of proppant flowback,leaving flowback program design without theoretical guidance and resulting in high uncertainty in prevention effectiveness.This paper has further modified the CFD-DEM(Computational Fluid Dynamics-Discrete Element Method)coupling interface by introducing fracture closure pressure into the particle motion equation.Based on the dynamic mesh,the fracture width in the CFD model is adjusted in real time to establish a numerical simulation method that considers fracture closure and synchronous changes in the flow field.By establishing flow similarity at the perforations,a near-wellbore flow field is created in the scaled model that is representative of field conditions,ensuring the practical value of the experimental results.Based on proppant particle force analysis during flowback,we investigated the impact of closure pressure,friction coefficient,perforation parameters,fracture dip angle,proppant particle size combination on proppant flowback.The research indicates that the existence of a threshold closure pressure arises from the competition between the lateral force(driving flowback)exerted by fracture closure on particles and the frictional force(resisting flowback)acting on particles.Below this threshold,increasing closure pressure enhances near-wellbore proppant flowback;above this threshold,increased closure pressure reduces proppant flowback.This threshold value is determined to be 1 MPa under the simulation conditions of this paper.The friction coefficient between particles and the fracture wall has greater impact on particle flowback than the friction coefficient between particles.In the vertical direction of the fracture,flowback is more probable for particles above the perforation.There is higher risk of particle flowback in horizontal fractures.The lateral distribution of large and small particles is more effective in preventing flowback than the vertical distribution.In the horizontal direction,particles nearer to the perforation have a higher probability of flowback.Strategies for proppant flowback control:the flow rate should be kept low initially,and then increased after the bottomhole pressure has been appropriately reduced;perforations should be placed in the upper part of the reservoir(vertical well);the sand concentration should not be increased in the later stages of fracturing to reduce the accumulation of proppant above the perforations;different size proppants should be injected in smaller sizes followed by larger sizes,with a slug of clean fluid in between to achieve a side-by-side placement of larger and smaller proppant,thereby mitigating proppant flowback.展开更多
Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)...Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)extension and OEE improvement is proposed.First,grid-connected power signals are obtained.Second,a model to optimize capacity allocation for three battery groups(BGs)in BESS is established considering LL and OEE,and it is solved by the designed improved beetle swarm antennae search algorithm.Then,a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units(BUs)during operation to keep good sustainable dispatchability.Then,a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE,and also keeps consistency of state of charge for BUs simultaneously.The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined.The lower layer,considering PCS efficiency under different working conditions,finishes power allocation from each BG into BUs inside it.Subsequently,an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time.Finally,the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively,which verifies its correctness and validity.展开更多
As the core component of circulating fluidized bed boiler, the efficiency of separator directly affects the safe and economic operation of the unit. Two 300MW circulating fluidized bed boilers in Diaobingshan Gangue P...As the core component of circulating fluidized bed boiler, the efficiency of separator directly affects the safe and economic operation of the unit. Two 300MW circulating fluidized bed boilers in Diaobingshan Gangue Power Plant have been put into operation since 2009 and 2010. Because the separator is in a high temperature and high circulating ash operating environment, the inner cylinder of the separator is worn and deformed rapidly, and the efficiency of the separator is greatly reduced, resulting in excessively high bed temperature and separator temperature, an increase in the original amount of environmental protection, and an increase in the cost of environmental protection materials, which affects the safe and economic operation of the unit. In view of this phenomenon, Diaobingshan Coal Gangue Power Plant has improved the efficiency of two furnace separators. After the transformation and operation, the bed temperature and the outlet temperature of the separator have dropped significantly during the operation of the unit, and the original amount of environmental protection has dropped significantly, and the consumption of environmental protection materials has dropped significantly, and the energy-saving effect is remarkable.展开更多
Nitrogen （N） is one of most important nutrients for crop production, which makes up 1%-5% of total plant dry matter （Marschner, 2012）. Due to the limited availability of N in soil, application of N fertilizers has...Nitrogen （N） is one of most important nutrients for crop production, which makes up 1%-5% of total plant dry matter （Marschner, 2012）. Due to the limited availability of N in soil, application of N fertilizers has been an important agronomic practice to increase crop yield. However, over-application of N fertilizers has caused pollution of N in soil, water and air. It was estimated that the nitrogen use efficiency （NUE, the total biomass or grain yield produced per unit of applied fertilizer N） in cereal crops is as low as 33% （Raun and Johnson, 1999）. Therefore, improving NUE together with reducing application of N fertilizers is an important issue for environment and sustainable production of crops. This is especially important for rice, which is a staple food for half population in the world.展开更多
文摘The modernization of the Traditional East Medicine industry has increasingly emphasized the role of collaborative innovation across the entire industrial chain.This paper investigates the mechanisms by which experts in cultivation,processing,R&D,production,and clinical application interact to enhance overall efficiency.By analyzing the bottlenecks in resource allocation,knowledge integration,and institutional design,the study proposes a comprehensive framework of collaborative mechanisms.The results highlight that multi-dimensional collaboration not only improves innovation efficiency but also accelerates the translation of scientific research into industrial outcomes.The findings provide theoretical support and practical implications for improving the synergy of experts in the Traditional East Medicine industry and contribute to the sustainable development of traditional medicine under modern industrial demands.
基金supported by the National Key R&D Program of China(2022YFB4300500).
文摘The multi-mode integrated railway system,anchored by the high-speed railway,caters to the diverse travel requirements both within and between cities,offering safe,comfortable,punctual,and eco-friendly transportation services.With the expansion of the railway networks,enhancing the efficiency and safety of the comprehensive system has become a crucial issue in the advanced development of railway transportation.In light of the prevailing application of artificial intelligence technologies within railway systems,this study leverages large model technology characterized by robust learning capabilities,efficient associative abilities,and linkage analysis to propose an Artificial-intelligent(AI)-powered railway control and dispatching system.This system is elaborately designed with four core functions,including global optimum unattended dispatching,synergetic transportation in multiple modes,high-speed automatic control,and precise maintenance decision and execution.The deployment pathway and essential tasks of the system are further delineated,alongside the challenges and obstacles encountered.The AI-powered system promises a significant enhancement in the operational efficiency and safety of the composite railway system,ensuring a more effective alignment between transportation services and passenger demands.
文摘Enhancing the efficiency of Rankine cycles is crucial for improving the performance of thermal power plants,as it directly impacts operational costs and emissions in light of energy transition goals.This study sets itself apart from existing research by applying a novel optimization technique to a basic ideal Rankine cycle,focusing on a specific power plant that has not been previously analyzed.Currently,this cycle operates at 41%efficiency and a steam quality of 76%,constrained by fixed operational parameters.The primary objectives are to increase thermal efficiency beyond 46%and raise steam quality above 85%,while adhering to operational limits:a boiler pressure not exceeding 15 MPa,condenser pressure not dropping below 10 kPa,and turbine temperature not surpassing 500℃.This study utilizes numerical simulations to model the effects of varying boiler pressure(Pb)and condenser pressure(Pc)within the ranges of 12MPa<Pb<15 MPa and 5 kPa<Pc<10 kPa.By systematically adjusting these parameters,the proposed aimto identify optimal conditions that maximize efficiency and performance within specified constraints.The findings will provide valuable insights for power plant operators seeking to optimize performance under real-world conditions,contributing to more efficient and sustainable power generation.
基金Project(51405010)supported by the National Natural Science Foundation of ChinaProject(2011BAG09B00)supported by the National Science and Technology Support Program of China
文摘For the purpose of improving efficiency and realizing start–stop function, an electric oil pump(EOP) is integrated into an 8-speed automatic transmission(AT). A mathematical model is built to calculate the transmission power loss and the hydraulic system leakage. Based on this model, a flow-based control strategy is developed for EOP to satisfy the system flow requirement. This control strategy is verified through the forward driving simulation. The results indicate that there is a best combination for the size of mechanical oil pump(MOP) and EOP in terms of minimum energy consumption. In order to get a quick and smooth starting process, control strategies of the EOP and the on-coming clutch are proposed. The test environment on a prototype vehicle is built to verify the feasibility of the integrated EOP and its control strategies. The results show that the selected EOP can satisfy the flow requirement and a quick and smooth starting performance is achieved in the start–stop function. This research has a high value for the forward design of EOP in automatic transmissions with respect to efficiency improvement and start–stop function.
文摘PEM （Proton Exchange Membrane） fuel cell is a promising renewable energy source to a wide range of applications for its clean products and high power density. However, controlling its humidity is a challenging problem due to the interdependence of several phenomena contributing in membrane＇s water content. This work deals with efficiency improvement of PEM fuel cells via humidity control. An innovative strategy of control based on the model of Ref. [1] is proposed. It consists on regulating gas humidification rates according to the power demand so that to minimize power losses. The proposed control takes into consideration constraints related to humidification in order to avoid dry out or flooding of the membrane. Simulations results show that time-phasing between hydrogen and oxygen humidification rates plays an important role in minimizing power losses. The proposed control shows significant improvement in the fuel cell＇s efficiency up to 20%.
基金supported by grants from the National Natural Science Foundation of China(No.31471395)to Q.Z.the Key Research Projects of the Frontier Science of the Chinese Academy of Sciences(QYZDY-SSW-SMC002)to Q.Z
文摘In mammalians, the state of a somatic cell can be reversed from the terminal state to the totipotent state by means of somatic cell nuclear transfer （SCNT） （Gurdon, 1962） or induced pluripotent stem cells （iPSCs） （Takahashi and Yamanaka, 2006）. The DNA methylation and transcriptome profiles of embryonic stern cells （ESCs） derived from SCNT embryos （NT-ESCs） correspond closely to those of ESCs derived from in vitro fertilization embryos （IVF- ESCs）. In contrast, iPSCs differ from both NT-ESCs and IVF-ESCs in that they retain the residual DNA methylation patterns of their parental somatic cells. As SCNT can be used to faithfully reprogram human somatic cells to pluripotency, it is ideal for cell replacement therapies （Ma et al., 2014）. Following the successful production of the first human NT-ESCs （Tachibana et al., 2013） and the later gen- eration of human NT-ESCs based on cells from elderly adults or pa- tient cells （Chung et al., 2014; Yamada et al., 2014）, a version of the SCNT technique for human therapeutics comes closer to reality. However, no matter what animal species or donor cell types are used in the cloned process, the cloning efficiency remains undesir- able. Besides, there are many phenotypic abnormalities in cloned animals, containing frequent embryonic and perinatal death and placentomegaly, and the underlying mechanisms remain unclear （Yang et al, 2007）.
文摘In my country, most of the mines are located in an area with a complex geological environment. Therefore, the mining and measurement of the mines are difficult and dangerous. Since the quality and efficiency of the mine are directly affected by the mine survey work during the mining process, the mining unit should pay attention to the development process of the mine survey work and to improve the efficiency of the mine survey work. At this stage, compared with the mine measurement technology of developed countries, my country's mine measurement technology still has a certain gap and a lot of room for improvement, and it is impossible to accurately guarantee the validity and standardization of mine measurement. Based on this, this paper explores how to improve the efficiency of mine surveying, aiming to provide some valuable references for mine surveying.
文摘The conventional P ＆ O （perturb-and-observe） method, which is the most widely used as MPPT （maximum power point tracking） control, has the problem of low efficiency and unstable operation when solar radiation changes drastically. Aiming at this problem, this paper improves the conventional P ＆ O method to reduce the bad effect of solar radiation by shortening the sampling interval of PV module＇s output power while keeping the operating period unchanged. Experiments are conducted to study efficiency gains of improved method when solar radiation changes drastically. The result shows that, by this method, the efficiency of MPPT control can be increased 17% in average when PV module simulator is used and 20% at maximum when actual PV module is used, compared with the conventional P ＆ O method.
文摘In the high school mathematics classroom under the background of new curriculum reform, students are the main body of teaching, which is different from traditional teaching. Teachers need to clearly realize the significance of students' main body status, pay attention to students' subjectivity in the classroom, and promote quality education from the perspective of students. In senior high school, students' learning background, learning style and character are quite different, so they are quite different when analyzing typical problems. In high school mathematics teaching, this kind of personalized difference will also affect students' learning ability. In this regard, teachers should start from the perspective of students' subject, pay attention to the differences of students, and create an efficient mathematics classroom. Under the new situation, to develop high school mathematics teaching well, only by exploring teaching problems from a new perspective and establishing new teaching concepts can the rapid development of mathematics teaching reform be promoted. Below, the article puts forward some suggestions on strategies to improve the efficiency of high school mathematics classroom teaching under the background of the new curriculum.
文摘SPECIAL|Eyes on Academic Publishing in AI Era At a time when artificial intelligence(AI)is permeating many aspects of human life,academic publishing is faced with new challenges:How should academic journals safeguard scholarly quality and research integrity against AI misuse?How should we improve efficiency with the aid of AI?
文摘Computer analysis of electrocardiograms(ECGs)was introduced more than 50 years ago,with the aim to improve efficiency and clinical workflow.[1,2]However,inaccuracies have been documented in the literature.[3,4]Research indicates that emergency department(ED)clinician interruptions occur every 4-10 min,which is significantly more common than in other specialties.[5]This increases the cognitive load and error rates and impacts patient care and clinical effi ciency.[1,2,5]De-prioritization protocols have been introduced in certain centers in the United Kingdom(UK),removing the need for clinician ECG interpretation where ECGs have been interpreted as normal by the machine.
基金Supported by National Forestry Science and Technology Key Promotion Program([2014]TZYN01)~~
文摘We applied water releasing from rootstocks technique and Juglans sigillata in Yangbi was pruned in the shape of opened-heart or round-heart shape. By bal- anced fertilization, survival rate of grafted walnuts can be improved. We reviewed technologies to enhance walnut quality and production efficiency in Gongshan Derung and Nu Autonomous County for reference.
基金Education and Teaching Research Project of Beijing University of Technology(ER2024KCB08)。
文摘With the rapid development of artificial intelligence technology,AIGC(Artificial Intelligence-Generated Content)has triggered profound changes in the field of high-level language programming courses.This paper deeply explored the application principles,advantages,and limitations of AIGC in intelligent code generation,analyzed the new mode of human-computer collaboration in high-level language programming courses driven by AIGC,discussed the impact of human-computer collaboration on programming efficiency and code quality through practical case studies,and looks forward to future development trends.This research aims to provide theoretical and practical guidance for high-level language programming courses and promote innovative development of high-level language programming courses under the human-computer collaboration paradigm.
文摘Hydrodynamic cavitation,as an efficient technique applied in many physical and chemical treatment methods,has been widely used by various industries and in several technological fields.Relevant generators,designed with specific structures and parameters,can produce cavitation effects,thereby enabling effective treatment and reasonable transformation of substances.This paper reviews the design principles,performance,and practical applications associated with different types of cavitation generators,aiming to provide theoretical support for the optimization of these systems.It systematically analyzes the underpinning mechanisms and the various factors influencing the cavitation phenomena,also conducting a comparative analysis of the performance of different types of generators.Specific applications dealing with wastewater treatment,chemical reaction acceleration,and other fields are discussed together with the advantages,disadvantages,and applicability of each type of cavitation generator.We also explore research progress in areas such as cavitation stability,energy efficiency,and equipment design upgrades.The study concludes by forecasting the application prospects of intelligent design and computational fluid dynamics(CFD)in optimizing and advancing cavitation generators.It proposes new ideas for the further development of cavitation technology and highlights directions for its widespread future application.
基金Supported by Hunan Forestry Science and Technology Plan(OT-S-KTA5,2024YBC15)Science and Technology Plan of Hunan Province(2021SFQ19).
文摘In this paper,different stands in Xianzhong Nursery of Pingjiang were selected as the research object to study the runoff generation and soil loss characteristics of different stands.The results showed that the annual surface runoff of each model in Pingjiang was between 50.50 and 70.38 mm,and the annual surface runoff of each stand decreased with years.There was no significant difference in the annual runoff between each stand,nor between each stand and its control.There were significant differences in soil erosion modulus among the models,and the number ranged from 139.20 to 197.79 t/(km^(2)·y).
基金supported by the Natural Science Foundation of Hunan Province(Grant No.2024JJ4059)Changsha Outstanding Innovative Youth Training Program(Grant No.kq2306010)+1 种基金the National Natural Science Foundation of China(Grant No.52176093)the Central South University Innovation-Driven Research Programme(Grant No.2023CXQD055)。
文摘Parabolic trough collector is a promising technology for both domestic and industrial heat supplies.To enhance the collector efficiency,a modified trough receiver with dozens of V-grooved light traps incorporated into its lower-half absorber was introduced.For assessing the performance of this receiver,a solar-thermal-stress coupled model was established.Using this model,firstly,the effects of the V-grooved light traps were investigated.The results reveal that,compared to the conventional trough receiver,the modified trough receivers equipped with different traps can reduce their optical losses by 81.9-138.0 Wm^(-1)(i.e.,15.0%-25.2%),improving their optical efficiencies by 1.60%-2.69%.However,these traps also result in increased thermal loss from the receiver.Therefore,there is no single optimal modified trough receiver that consistently outperforms all other receivers across all possible conditions.Nonetheless,the MTR30-3 and MTR60-3 receivers emerge as the optimized choices due to their better solar-thermal performance.Subsequently,performance evaluation reveals that the two optimized receivers can enhance the receiver efficiencies within the typical solar irradiance range by 0.02%-2.65%and 0.05%-1.70%when the inlet fluid temperatures are below 488 and 523 K,respectively.Consequently,the collector efficiencies can be improved by 0.02%-2.49%and 0.05%-1.60%,respectively.Additionally,thermal stress analysis verifies that the two optimized receivers remain within safe limits under all typical conditions.Given that the heating temperature of a typical solar collector for domestic or industrial heat supply is typically below 523 K,the integration of the two optimized receivers has the capability to effectively enhance the overall collector efficiency.
基金support of the National Natural Science Foundation of China(Grant No.52474069)the National Natural Science Foundation of China(No.52104060).
文摘Proppant flowback in the post-fracturing flowback period not only reduces the fracture conductivity but also damages equipment.Due to the current lack of experimental or numerical simulation methods for proppant flowback in partial closure fracture,the mechanisms and patterns of proppant flowback remain unclear.This makes it difficult to predict the risks of proppant flowback,leaving flowback program design without theoretical guidance and resulting in high uncertainty in prevention effectiveness.This paper has further modified the CFD-DEM(Computational Fluid Dynamics-Discrete Element Method)coupling interface by introducing fracture closure pressure into the particle motion equation.Based on the dynamic mesh,the fracture width in the CFD model is adjusted in real time to establish a numerical simulation method that considers fracture closure and synchronous changes in the flow field.By establishing flow similarity at the perforations,a near-wellbore flow field is created in the scaled model that is representative of field conditions,ensuring the practical value of the experimental results.Based on proppant particle force analysis during flowback,we investigated the impact of closure pressure,friction coefficient,perforation parameters,fracture dip angle,proppant particle size combination on proppant flowback.The research indicates that the existence of a threshold closure pressure arises from the competition between the lateral force(driving flowback)exerted by fracture closure on particles and the frictional force(resisting flowback)acting on particles.Below this threshold,increasing closure pressure enhances near-wellbore proppant flowback;above this threshold,increased closure pressure reduces proppant flowback.This threshold value is determined to be 1 MPa under the simulation conditions of this paper.The friction coefficient between particles and the fracture wall has greater impact on particle flowback than the friction coefficient between particles.In the vertical direction of the fracture,flowback is more probable for particles above the perforation.There is higher risk of particle flowback in horizontal fractures.The lateral distribution of large and small particles is more effective in preventing flowback than the vertical distribution.In the horizontal direction,particles nearer to the perforation have a higher probability of flowback.Strategies for proppant flowback control:the flow rate should be kept low initially,and then increased after the bottomhole pressure has been appropriately reduced;perforations should be placed in the upper part of the reservoir(vertical well);the sand concentration should not be increased in the later stages of fracturing to reduce the accumulation of proppant above the perforations;different size proppants should be injected in smaller sizes followed by larger sizes,with a slug of clean fluid in between to achieve a side-by-side placement of larger and smaller proppant,thereby mitigating proppant flowback.
基金supported by the National Key Research and Development Program of China(No.2018YFE0122200)the National Natural Science Foundation of China(No.52077078)the Fundamental Research Funds for the Central Universities(No.2020MS090).
文摘Aiming at issues of life loss(LL)and overall energy efficiency(OEE)for battery energy storage system(BESS)in smoothing wind power fluctuations,a dynamic grouping control strategy of BESS for remaining useful life(RUL)extension and OEE improvement is proposed.First,grid-connected power signals are obtained.Second,a model to optimize capacity allocation for three battery groups(BGs)in BESS is established considering LL and OEE,and it is solved by the designed improved beetle swarm antennae search algorithm.Then,a dynamic grouping method is proposed to dynamically adjust the grouping state of battery units(BUs)during operation to keep good sustainable dispatchability.Then,a double-layer power allocation approach coordinated with multi-principle is designed to reduce LL and improve OEE,and also keeps consistency of state of charge for BUs simultaneously.The upper layer achieves power allocation from BESS into the three BGs and power allocation method for each BG is determined.The lower layer,considering PCS efficiency under different working conditions,finishes power allocation from each BG into BUs inside it.Subsequently,an RUL evaluation model based on the swing door trend algorithm is built to shorten required calculation time.Finally,the proposed control strategy is simulated and results compared with other strategies demonstrate the proposed strategy acquires the longest RUL and highest OEE with smoothing wind power fluctuations effectively,which verifies its correctness and validity.
文摘As the core component of circulating fluidized bed boiler, the efficiency of separator directly affects the safe and economic operation of the unit. Two 300MW circulating fluidized bed boilers in Diaobingshan Gangue Power Plant have been put into operation since 2009 and 2010. Because the separator is in a high temperature and high circulating ash operating environment, the inner cylinder of the separator is worn and deformed rapidly, and the efficiency of the separator is greatly reduced, resulting in excessively high bed temperature and separator temperature, an increase in the original amount of environmental protection, and an increase in the cost of environmental protection materials, which affects the safe and economic operation of the unit. In view of this phenomenon, Diaobingshan Coal Gangue Power Plant has improved the efficiency of two furnace separators. After the transformation and operation, the bed temperature and the outlet temperature of the separator have dropped significantly during the operation of the unit, and the original amount of environmental protection has dropped significantly, and the consumption of environmental protection materials has dropped significantly, and the energy-saving effect is remarkable.
文摘Nitrogen （N） is one of most important nutrients for crop production, which makes up 1%-5% of total plant dry matter （Marschner, 2012）. Due to the limited availability of N in soil, application of N fertilizers has been an important agronomic practice to increase crop yield. However, over-application of N fertilizers has caused pollution of N in soil, water and air. It was estimated that the nitrogen use efficiency （NUE, the total biomass or grain yield produced per unit of applied fertilizer N） in cereal crops is as low as 33% （Raun and Johnson, 1999）. Therefore, improving NUE together with reducing application of N fertilizers is an important issue for environment and sustainable production of crops. This is especially important for rice, which is a staple food for half population in the world.
