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Research on a TOPSIS energy efficiency evaluation system for crude oil gathering and transportation systems based on a GA-BP neural network 被引量:1
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作者 Xue-Qiang Zhang Qing-Lin Cheng +2 位作者 Wei Sun Yi Zhao Zhi-Min Li 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期621-640,共20页
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
关键词 Crude oil gathering and transportation system GA-BP neural network Energy efficiency evaluation TOPSIS evaluation method Energy saving and consumption reduction
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OsNPF3.1,a nitrate,abscisic acid and gibberellin transporter gene,is essential for rice tillering and nitrogen utilization efficiency
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作者 Junnan Hang Bowen Wu +3 位作者 Diyang Qiu Guo Yang Zhongming Fang Mingyong Zhang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第4期1087-1104,共18页
Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone ... Low-affinity nitrate transporter genes have been identified in subfamilies 4-8 of the rice nitrate transporter 1(NRT1)/peptide transporter family(NPF),but the OsNPF3 subfamily responsible for nitrate and phytohormone transport and rice growth and development remains unknown.In this study,we described OsNPF3.1 as an essential nitrate and phytohormone transporter gene for rice tillering and nitrogen utilization efficiency(NUtE).OsNPF3.1 possesses four major haplotypes of its promoter sequence in 517 cultivars,and its expression is positively associated with tiller number.Its expression was higher in the basal part,culm,and leaf blade than in other parts of the plant,and was strongly induced by nitrate,abscisic acid(ABA)and gibberellin 3(GA_3)in the root and shoot of rice.Electrophysiological experiments demonstrated that OsNPF3.1 is a pH-dependent low-affinity nitrate transporter,with rice protoplast uptake assays showing it to be an ABA and GA_3 transporter.OsNPF3.1 overexpression significantly promoted ABA accumulation in the roots and GA accumulation in the basal part of the plant which inhibited axillary bud outgrowth and rice tillering,especially at high nitrate concentrations.The NUtE of OsNPF3.1-overexpressing plants was enhanced under low and medium nitrate concentrations,whereas the NUtE of OsNPF3.1 clustered regularly interspaced short palindromic repeats(CRISPR)plants was increased under high nitrate concentrations.The results indicate that OsNPF3.1 transports nitrate and phytohormones in different rice tissues under different nitrate concentrations.The altered OsNPF3.1 expression improves NUtE in the OsNPF3.1-overexpressing and CRISPR lines at low and high nitrate concentrations,respectively. 展开更多
关键词 rice tillering grain yield PHYTOHORMONE NITRATE transporter nitrogen utilization efficiency
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Indica rice restorer lines with large sink potential exhibit improved nutrient transportation to the panicle,which enhances both yield and nitrogen-use efficiency 被引量:2
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作者 TIAN Qing-lan HE Lian-hua +5 位作者 LIAO Shuang LI Wu DENG Fei ZHOU Wei ZHONG Xiao-yuan REN Wan-jun 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2021年第6期1438-1456,共19页
The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high... The yield and nitrogen use efficiency(NUE)of hybrid rice combinations are closely related to restorer line.Therefore,it is essential to evaluate the agronomic characteristics of restorer lines with high yield and high NUE(HYHN).However,it is unclear which restorer lines are HYHN,and neither have the common agronomic traits of the HYHN restorer lines been identified.Aiming to address this issue,we conducted two filed experiments using three nitrogen applications,which screened five HYHN restorer lines from 15 indica restorer lines.Yield,NUE and nutrient transportation of restorer lines with different yields and NUE types were examined.Yield and total nitrogen absorption in aboveground biomass(TNA)increased,whereas NUE for grain production decreased with increasing nitrogen application levels.The HYHN restorer lines had large spikelets and high weight per panicle that were significantly positively correlated with yield and NUE.Therefore,large sink potential may be beneficial for both yield and NUE.We further studied the differences in nutrient transportation to panicles between the HYHN and low yield and low NUE(LYLN)restorer lines and found that the former had a higher nitrogen absorption level and dry matter weight ratios of panicle in maturity.Moreover,the HYHN lines also had a higher root and neck-panicle node bleeding intensity per stem after heading and more developed vascular bundles of neck-panicle nodes and leaves than the LYLN lines,which could contribute to the transportation of nutrients from root to ground and from stem and leaf to spike.Therefore,the advantages of large sink potential of the HYHN restorer lines include large nutrient accumulation in and distribution to the panicles and smooth flow of nutrients along the transportation channels. 展开更多
关键词 indica hybrid rice restorer lines grain yield nitrogen-use efficiency sink potential nutrient transportation
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The heterogeneous impact of China-Europe railway express on the efficiency of logistics industry in node cities
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作者 Yanliang Niu Jin Liu +1 位作者 Xining Yang Chuan Wang 《Railway Sciences》 2024年第3期279-294,共16页
Purpose-The spatiotemporal compression effect of China-Europe Railway Express(CR-Express)can reduce the filow costs of resources between China's node cities.Additionally,it can break through the limitations of low... Purpose-The spatiotemporal compression effect of China-Europe Railway Express(CR-Express)can reduce the filow costs of resources between China's node cities.Additionally,it can break through the limitations of low-added-value marine products,significantly impacting the logistics industry efficiency.However,there are few literature verifying and analyzing its heterogeneity.This study explores the impact of CR-Express on the efficiency of logistics industry in node cities and analyzes the heterogeneity.Design/methodology/approach-First,this study uses panel data to measure the efficiency of node city logistics industry.Secondiy,this study discusses the impact of the opening of CR-Express on the efficiency of logistics industry in node cities based on the multi-period differential model.Finally,according to the node city difference,the sample city experimental group is grouped for heterogeneity analysis.Findings-The results show that CR-Express can promote the urban logistics industry efficiency,with an average effect of 4.55%.According to the urban characteristics classification,the heterogeneity analysis shows that the efficiency improvement effect of logistics industry in inland cities is more obvious.The improvement effect of node cities and central cities in central and western China is stronger,especially in the sample of megacities and type I big cities.Compared with non-value chain industrial products,the CR-Express has significant promotion effects on the logistics efficiency of the cities where main goods are value chain products.Originality/value-Under the background of double cycle development,this paper can provide a scientific basis for the investment benefit evaluation of CR-Express construction and the follow-up route planning. 展开更多
关键词 Logistics industry efficiency China-Europe railway express Difference-in-difference model HETEROGENEITY transportation infrastructure Paper type Research paper
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The Energy Efficiency Gap in Maritime Transport 被引量:2
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作者 Michele Acciaro Peter Nyegaard Hoffmann Magnus Strandmyr Eide 《Journal of Shipping and Ocean Engineering》 2013年第1期1-10,共10页
There is evidence that the shipping industry could achieve energy efficiency gains through the implementation of new technologies, with considerable reductions of fuel costs and emissions to air in the sector. Althoug... There is evidence that the shipping industry could achieve energy efficiency gains through the implementation of new technologies, with considerable reductions of fuel costs and emissions to air in the sector. Although the cost reducing effects of some new technologies are well established, companies appear reluctant to innovate despite the financial and societal benefits, as a result of what is referred to as the energy efficiency gap. The global emission impacts of the shipping industry, most notably of greenhouse gases, sulphur and nitrogen oxides are increasingly attracting the attention of regulators, non-governmental organisations and the media, and shipping companies are under pressure to find new ways to reduce their emission footprint. Understanding the determinants of the energy efficiency gap in shipping is then critical in improving the environmental profile of the industry. This paper presents the results of a survey among Norwegian shipping companies aimed at gaining a better understanding of the barriers to implementation of new cost saving technologies. The paper assesses the technical barriers that have traditionally been indicated as the main cause of the energy efficiency gap in shipping. The paper results indicate that next to technical factors, important barriers are constituted also by managerial practices and legal constraints. 展开更多
关键词 Energy efficiency gap emission reduction technologies barriers maritime transport.
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Spatial network structure of transportation carbon emission efficiency in China and its influencing factors 被引量:1
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作者 Haiqin Shao Zhaofeng Wang 《Chinese Journal of Population,Resources and Environment》 2021年第4期295-303,共9页
Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation indu... Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation industry and the relevant region.Based on the ideal point cross-efficiency(IPCE)model,the social network analysis method was employed herein to explore the spatial correlation network structure of China’s provincial TCEE and its influencing factors.The results obtained showed the following outcomes.(1)During the study period,China’s provincial TCEE formed a complex and multithreaded network association relationship,but its network association structure was still relatively loose and presented the hierarchical gradient characteristics of dense in the east and sparse in the west.(2)The correlation of China’s TCEE formed a block segmentation based on the regional boundaries,and its factional structure was relatively obvious.The eastern region was closely connected with the central region,and generally connected with the western and northeastern regions.The central region was mainly connected with the eastern and western regions,and relatively less connected with the northeastern region.Besides,the northeastern region was weakly connected with the western region.(3)Shanghai,Beijing,Zhejiang,Guangdong,Jiangsu,Tianjin,and other developed provinces were in the core leading position in the TCEE network,which significantly impacted the spatial correlation of TCEE.However,Heilongjiang,Jilin,Xinjiang,Qinghai,and other remote provinces in the northeast and northwest were at the absolute edge of the network,which weakly impacted the spatial correlation of TCEE.(4)Provincial distance,economic development-level difference,transportation intensity difference,and transportation structure difference had significant negative impacts on the spatial correlation network of China’s provincial TCEE.In contrast,the energy-saving technology level difference had a significant positive impact on it.The regression coefficients of transportation energy structure and environmental regulation differences were positive but insignificant;their response mechanism and effects need to be improved and enhanced. 展开更多
关键词 transportation carbon emission efficiency Spatial network structure Influencing factor Social network analysis
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Dimethyl acridine-based self-assembled monolayer as a hole transport layer for highly efficient inverted perovskite solar cells
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作者 Liufei Li Rongyao Lv +11 位作者 Guiqi Zhang Bing Cai Xin Yu Yandong Wang Shantao Zhang Xiaofen Jiang Xinyu Li Shuang Gao Xue Wang Ziqi Hu Wen-Hua Zhang Shangfeng Yang 《Energy Materials and Devices》 2024年第2期29-38,共10页
Self-assembled monolayers(SAMs)have recently emerged as excellent hole transport materials in inverted perovskite solar cells(PSCs)owing to their ability to minimize parasitic absorption,regulate energy level alignmen... Self-assembled monolayers(SAMs)have recently emerged as excellent hole transport materials in inverted perovskite solar cells(PSCs)owing to their ability to minimize parasitic absorption,regulate energy level alignment,and passivate perovskite defects.Herein,we design and synthesize a novel dimethyl acridinebased SAM,[2-(9,10-dihydro-9,9-dimethylacridine-10-yl)ethyl]phosphonic acid(2PADmA),and employ it as a hole-transporting layer in inverted PSCs.Experimental results show that the 2PADmA SAM can modulate perovskite crystallization,facilitate carrier transport,passivate perovskite defects,and reduce nonradiative recombination.Consequently,the 2PADmA-based device achieves an enhanced power conversion efficiency(PCE)of 24.01%and an improved fill factor(FF)of 83.92%compared to the commonly reported[2-(9H-carbazol-9-yl)ethyl]phosphonic acid(2PACz)-based control device with a PCE of 22.32%and FF of 78.42%,while both devices exhibit comparable open-circuit voltage and short-circuit current density.In addition,2PADmA-based devices exhibit outstanding dark storage and thermal stabilities,retaining approximately~98%and 87%of their initial PCEs after 1080 h of dark storage and 400 h of heating at 85°C,respectively,both considerably superior to the control device. 展开更多
关键词 perovskite solar cells hole transport layer self-assembled monolayer power conversion efficiency stability
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High Efficiency LSM with High Flux Density for Transportation
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作者 Nobuo Fujii Mitsunobu Terata Takeshi Mizuma 《Journal of Transportation Technologies》 2011年第4期102-106,共5页
A new linear synchronous motor (LSM) with permanent magnet (PM) is proposed to develop a linear motor for transportation with high efficiency. The LSM has very high air-gap flux density beyond the remanent magnetizati... A new linear synchronous motor (LSM) with permanent magnet (PM) is proposed to develop a linear motor for transportation with high efficiency. The LSM has very high air-gap flux density beyond the remanent magnetization of rare earth PM, which is generated by a special field structure with rare earth PM. Two PMs are arranged to form a triangle over each pole to concentrate the flux of PMs. The maximum value of air-gap flux density is limited to the magnetic saturated value in the core of field and armature, respectively, which is about 2T. The configuration is insusceptible to armature reaction because of large equivalent magnetic resistance in the flux path. The characteristics are analyzed using a two-dimensional finite element method (FEM) considering the core material. For high air-gap flux density and small armature reaction, the very high thrust density beyond the conventional maximum value of 100kN/m2 can be obtained. Using normal thrust density with small magneto-motive force (mmf) of armature, this LSM has efficiency and power factor that are as high as or higher than a rotational motor. 展开更多
关键词 Permanent Magnet SYNCHRONOUS MOTOR LINEAR SYNCHRONOUS MOTOR LSM HIGH flux Density HIGH efficiency LINEAR MOTOR transportATION
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Improving the efficiency of transport systems using simulation
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作者 Bushuev Sergey Valentinovich Kovalev Igor Alexandrovich +1 位作者 Permikin Vadim Yurievich Anashkina Nataliia Yurievna 《系统仿真学报》 CAS CSCD 北大核心 2020年第2期340-345,共6页
The article describes the possibilities of application of simulation modeling for the analysis of infrastructure and technology of transport services of enterprises. The main technological and possible economic effect... The article describes the possibilities of application of simulation modeling for the analysis of infrastructure and technology of transport services of enterprises. The main technological and possible economic effects for the enterprises arising at performance of modeling of a transport component of their work are resulted. 展开更多
关键词 SERVICE Improving the efficiency of transport systems using simulation
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Evaluation of the impacts of adaptive cruise control system on improving fuel efficiency of urban road traffic 被引量:2
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作者 李烨 王炜 +2 位作者 王昊 邢璐 刘善文 《Journal of Southeast University(English Edition)》 EI CAS 2017年第2期230-235,共6页
The impact of the adaptive cruise control( ACC)system on improving fuel efficiency is evaluated based on the vehicle-specific power. The intelligent driver model was first modified to simulate the ACC system and it ... The impact of the adaptive cruise control( ACC)system on improving fuel efficiency is evaluated based on the vehicle-specific power. The intelligent driver model was first modified to simulate the ACC system and it was calibrated by using empirical traffic data. Then, a five-step procedure based on the vehicle-specific power was introduced to calculate fuel efficiency. Five scenarios with different ACC ratios were tested in simulation experiments, and sensitivity analyses of two key ACC factors affecting the perception-reaction time and time headway were also conducted. The simulation results indicate that all the scenarios with ACC vehicles have positive impacts on reducing fuel consumption. Furthermore, from the perspective of fuel efficiency, the extremely small value of the perception-reaction time of the ACC system is not necessary due to the fact that the value of 0.5 and 0.1 s can almost lead to the same reduction in fuel consumption. Finally, the designed time headway of the ACC system is also proposed to be large enough for fuel efficiency, although its small value can increase capacity. The findings of this study provide useful information for connected vehicles and autonomous vehicle manufacturers to improve fuel efficiency on roadways. 展开更多
关键词 intelligent transportation system vehicle-specific power fuel efficiency ENERGY connected vehicle automated vehicle
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Network-level optimization method for road network maintenance programming based on network efficiency 被引量:5
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作者 张林雪 秦进 +2 位作者 贺钰昕 叶勇 倪玲霖 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4882-4889,共8页
To maintain their capacity,transportation infrastructures are in need of regular maintenance and rehabilitation.The major challenge facing transportation engineers is the network-level policies to maintain the deterio... To maintain their capacity,transportation infrastructures are in need of regular maintenance and rehabilitation.The major challenge facing transportation engineers is the network-level policies to maintain the deteriorating roads at an acceptable level of serviceability.In this work,a quantitative transportation network efficiency measure is presented and then how to determine optimally network-level road maintenance policy depending on the road importance to the network performance has been demonstrated.The examples show that the different roads should be set different maintenance time points in terms of the retention capacities of the roads,because the different roads play different roles in network and have different important degrees to the network performance.This network-level road maintenance optimization method could not only save lots of infrastructure investments,but also ensure the service level of the existing transportation system. 展开更多
关键词 transportation network maintenance policy network efficiency time point sensitivity analysis
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Composite electron transport layer for efficient N-I-P type monolithic perovskite/silicon tandem solar cells with high open-circuit voltage 被引量:2
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作者 Bingbing Chen Pengyang Wang +8 位作者 Renjie Li Ningyu Ren Yongliang Chen Wei Han Lingling Yan Qian Huang Dekun Zhang Ying Zhao Xiaodan Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2021年第12期461-467,I0011,共8页
Perovskite/silicon tandem solar cells(PSTSCs) have exhibited huge technological potential for breaking the Shockley-Queisser limit of single-junction solar cells. The efficiency of P-I-N type PSTSCs has surpassed the ... Perovskite/silicon tandem solar cells(PSTSCs) have exhibited huge technological potential for breaking the Shockley-Queisser limit of single-junction solar cells. The efficiency of P-I-N type PSTSCs has surpassed the single-junction limit, while the performance of N-I-P type PSTSCs is far below the theoretical value. Here, we developed a composite electron transport layer for N-I-P type monolithic PSTSCs with enhanced open-circuit voltage(VOC) and power conversion efficiency(PCE). Lithium chloride(Li Cl) was added into the tin oxide(SnO_(2)) precursor solution, which simultaneously passivated the defects and increased the electron injection driving force at the electron transfer layer(ETL)/perovskite interface.Eventually, we achieved monolithic PSTSCs with an efficiency of 25.42% and V_(OC) of 1.92 V, which is the highest PCE and VOCin N-I-P type perovskite/Si tandem devices. This work on interface engineering for improving the PCE of monolithic PSTSCs may bring a new hot point about perovskite-based tandem devices. 展开更多
关键词 Lithium chloride additive Electron transport layer High efficiency Perovskite/Si tandem solar cells
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Energy-Efficient and Reliable Transport Protocols for Wireless Sensor Networks: State-of-Art 被引量:1
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作者 Ahmed Ayadi 《Wireless Sensor Network》 2011年第3期106-113,共8页
New wireless sensor network applications (e.g., military surveillance) require higher reliability than a simple best effort service could provide. Classical reliable transport protocols like Transmission Control Proto... New wireless sensor network applications (e.g., military surveillance) require higher reliability than a simple best effort service could provide. Classical reliable transport protocols like Transmission Control Protocol (TCP) are not well suited for wireless sensor networks due to both the characteristics of the network nodes (low computing power, strong energy constraints) and those of the main applications running on those nodes (low data rates). Recent researches present new transport protocols for wireless sensor networks providing various type of reliability and using new mechanisms for loss detection and recovery, and congestion control. This paper presents a survey on reliable transport protocol for WSNs. 展开更多
关键词 WIRELESS Sensor Networks transport PROTOCOL Reliability CONGESTION Control Energy efficiency
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Using KELEA (Kinetic Energy Limiting Electrostatic Attraction) to Improve the Efficiency of Fuel Combustion 被引量:1
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作者 W. John Martin 《Open Journal of Air Pollution》 2017年第3期103-116,共14页
There are many reports of devices and fuel additives being able to enhance the performance of automobiles and other forms of transportation that rely upon the combustion of gasoline or diesel fuels. The claims extend ... There are many reports of devices and fuel additives being able to enhance the performance of automobiles and other forms of transportation that rely upon the combustion of gasoline or diesel fuels. The claims extend from increased mileage and power to significant reductions in toxic exhaust emissions of carbon monoxide and unburnt hydrocarbons. Progress towards more widespread applications of means of improving fuel efficiency has been impeded by the lack of a coherent explanation of the mechanism of action. Fuel combustion allows for the conversion of much of the available chemical energy in volatile hydrocarbons to mechanical energy, which moves the pistons within an engine. It is proposed that the amount of chemical energy in hydrocarbons can be increased by the absorption of an environmental force termed KELEA (kinetic energy limiting electrostatic attraction). In addition to providing greater mechanical energy with relatively less heat output, the combustion of KELEA activated fuels proceeds further with less toxic emissions of carbon monoxide and unburnt hydrocarbons from incomplete combustion. KELEA activation of fuels should become standard practice in the transportation industry, with potential additional benefits in slowing the rate of global warming. 展开更多
关键词 KELEA Chemistry transportation Hydrocarbons Combustion Fuel efficiency Air Pollution Exhaust Carbon MONOXIDE Gasoline Diesel Global WARMING PHOTOSYNTHESIS Hydrogen Electrical CHARGES
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Recombination Efficiency and Width in Bilayer Organic Light-emitting Devices
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作者 PAN Yan-zhi LI Hong-jian +3 位作者 DAI Xiao-yu FANG An-le LI jia ZHU Ru-hui 《Semiconductor Photonics and Technology》 CAS 2006年第1期5-9,共5页
A bilayer model with ohmic anode contact and injection limited cathode contact has been proposed to calculate the recombination efficiency and recombination zone width of the device. The effects of the thickness of ho... A bilayer model with ohmic anode contact and injection limited cathode contact has been proposed to calculate the recombination efficiency and recombination zone width of the device. The effects of the thickness of hole transport layer and the barriers of organic/organic interface on the combination efficiency and recombination width have been discussed. It is found that: (1) When the electrons are blocked fully and the holes are not blocked significantly at the organic/organic interface, for a given Lh/L, the recombination efficiency increases with increasing the applied voltage, but at a higher applied voltage, the recombination efficiency decreases with increasing Lh/L; (2) The recombination efficiency increases with increasing applied voltage and Hh', and when applied voltage and Hh' exceed some value, the recombination efficiency appears as a plateau; (3) The recombination width decreases with increasing the applied voltage and Lh/L. This model might explain the relative experiment phenomena. 展开更多
关键词 Organic light-emitting devices Hole transport layer Recombination efficiency Recombination width
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A Higher-Efficient Non-Hydrostatic Finite Volume Model for Strong Three-Dimensional Free Surface Flows and Sediment Transport 被引量:1
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作者 LIU Xin MA Dian-guang ZHANG Qing-he 《China Ocean Engineering》 SCIE EI CSCD 2017年第6期736-746,共11页
In order to accurately simulate strong three-dimensional (3-D) free surface flows and sediment transport, the fully 3- D non-hydrostatic pressure models are developed based on the incompressible Navier-Stokes equati... In order to accurately simulate strong three-dimensional (3-D) free surface flows and sediment transport, the fully 3- D non-hydrostatic pressure models are developed based on the incompressible Navier-Stokes equations and convection-diffusion equation of sediment concentration with the mixing triangle and quadrilateral grids. The governing equations are discretized with the unstructured finite volume method in order to provide conservation properties of mass and momentum, and flexibility with practical application. It is shown that it is first-order accurate on nonuniform plane two-dimensional (2-D) grids and second-order accurate on uniform plane grids. A third-order approximation of the vertical velocity at the top-layer is applied. In such a way, free surface zero stress boundary condition is satisfied maturely, and very few vertical layers are needed to give an accurate solution even for complex discontinuous flow and short wave simulation. The model is applied to four examples to simulate strong 3-D free surface flows and sediment transport where non-hydrostatic pressures have a considerable effect on the velocity field. The newly developed model is verified against analytical solutions with an excellent agreement. 展开更多
关键词 higher-efficient NON-HYDROSTATIC strong 3-D free surface flows sediment transport 3-D numerical model
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To Improve Energy Efficiency via Car Driving Deduction by Land Use Planning
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作者 Mohammad Malekizadeh M. F. M. Zain +1 位作者 Amiruddin Ismail Ahmad Hami 《Open Journal of Energy Efficiency》 2013年第3期133-138,共6页
Urban area consumes about main percentage of used energy. Cities need basic review in land management, structure and form to minimize the use of energy which creating environmental pollution. Urban planners and design... Urban area consumes about main percentage of used energy. Cities need basic review in land management, structure and form to minimize the use of energy which creating environmental pollution. Urban planners and designers are looking for a solution and essential agreement in urban planning and designing principles that can decrease the pollution from rapid urbanization. Travelling is essential for daily needs of most people in urban area. Issues arise when one considers the amount of necessary fossil fuels used in the majority of daily commuting for accessibility to services. It is necessary to design a city to minimize the use of energy which creating environmental pollution. Research conducted in Subang Jaya in Malaysia in 2012 finds a variable which influences on use of car, propose of use of car and commuting distance by car. However it tried to find effect of train station and density on use of car for accessibility to this services and facilities. Findings illustrate neighbourhood distance from train station influences distance to facilities and services in neighbourhoods. However it illustrates derived distance by car was affected by residential lots distance from restaurant, work place, school, park, house area per person, and car ownership. 展开更多
关键词 TOWN & City PLANNING RAILWAY Systems URBAN Design transport PLANNING POLLUTION Energy efficiency
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Nitrogen Accumulation and Transport Characteristics and Grain Protein Content of Wheat Varieties with Different Nitrogen Efficiencies and Their Responses to Irrigation
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作者 Weina HE 《Asian Agricultural Research》 2022年第10期44-47,共4页
[Objectives]To explore the differences in nitrogen accumulation and transport characteristics and grain protein content of wheat varieties with different nitrogen efficiencies and their responses to irrigation.[Method... [Objectives]To explore the differences in nitrogen accumulation and transport characteristics and grain protein content of wheat varieties with different nitrogen efficiencies and their responses to irrigation.[Methods]Under field conditions,using nitrogen-inefficient varieties Luohan 17 and Xinhua 818 and nitrogen-efficient varieties Bainong 418 and Bainong 419 as materials,this paper studied the nitrogen accumulation and transport characteristics,grain protein content and protein yield of wheat with different nitrogen efficiencies under rainfed and irrigated conditions.[Results]Compared with the nitrogen-inefficient wheat varieties,the pre-flowering nitrogen transport and the shoot nitrogen accumulation at the mature stage of nitrogen-efficient wheat varieties decreased by 15.08%and 28.25%,respectively,and the grain protein content decreased by 11.66%,under rainfed conditions.Compared with rainfed conditions,nitrogen accumulation in shoots of nitrogen-inefficient wheat varieties and nitrogen-efficient wheat varieties at the mature stage increased by 6.59%and 67.05%,respectively,and grain protein content decreased by 13.50%and 3.47%,respectively,under irrigated conditions.The two nitrogen efficiency types of wheat had different responses to irrigation after flowering.After irrigation,the nitrogen accumulation of nitrogen-efficient varieties increased by 274.80%,while that of nitrogen-inefficient varieties decreased by 51.15%.Finally,the grain protein yield of nitrogen-inefficient wheat varieties remained stable,while the grain protein yield of nitrogen-efficient wheat varieties increased by 40.37%.[Conclusions]The nitrogen accumulation and transport characteristics and grain protein content of wheat varieties with different nitrogen efficiencies are different under different irrigation conditions.In production,it is necessary to take different irrigation measures in accordance with the difference in nitrogen efficiency of wheat varieties,so as to increase the protein content of wheat grains. 展开更多
关键词 IRRIGATION Wheat NITROGEN efficiency NITROGEN ACCUMULATION and transport Protein content
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Path selection and mechanism innovation of improving railway energy efficiency–from foreign experience and Chinese practice
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作者 Xinjun Zhou 《Railway Sciences》 2022年第2期324-344,共21页
Purpose–Under the dual pressure of resources and environment,many countries have focused on the role of railways in promoting low-carbon development of integrated transportation and of even the whole society.This pap... Purpose–Under the dual pressure of resources and environment,many countries have focused on the role of railways in promoting low-carbon development of integrated transportation and of even the whole society.This paper aims to provide a comprehensive study on methods to improve railway energy efficiency in other national railways and achievements made by China’s railways in the past practice,and then to propose ways in which in the future China’s railways could rationally select the path of improving energy efficiency regarding the needs of the nation’s ever-shifting development and carry out the re-engineering for mechanism innovation in energy conservation and emission reduction process.Design/methodology/approach–This paper first studies other national railways that have tried to promote the improvement of railway energy efficiency by the ways of technology,management and structural reconstruction to reduce energy consumption and carbon emissions.Among them,the effect of structural energy conservation and emission reduction has become more prominent.It has become the main energy conservation and emission reduction measure adopted by foreign railway sectors.The practice of energy conservation and emission reduction of railways in various countries has tended to shift from a technical level to a structural one.Findings–Key aspects in improving energy efficiency include re-optimization of energy structure,reinnovation of energy-saving technologies and optimization of transportation organization.Path selection includes continuing to promote electrified railway construction,increasing the use of new and renewable energy sources,and promoting the reform of railway transportation organizations.Originality/value–This paper provides further challenges and research directions in the proposed area and has referential value for the methodologies,approaches for practice in a Chinese context.To achieve the expected goals,relevant supporting policies and measures need to be formulated,including actively guiding integrated transportation toward railway-oriented development,promoting innovation in energy-saving and emission reduction mechanisms and strengthening policy incentives,focusing on improving the energy efficiency of railways through market behavior.At the same time,it is necessary to pay attention to new phenomena in the railway industry for track and analysis. 展开更多
关键词 China’s railways Energy efficiency Energy consumption structure transport organization optimization ELECTRIFICATION New energy Renewable energy
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无人驾驶汽车技术发展对未来城市轨道交通影响研究
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作者 葛世平 《城市轨道交通研究》 北大核心 2025年第1期1-5,14,共6页
[目的]探讨无人驾驶汽车技术的发展对未来城市轨道交通可能产生的影响,并分析无人驾驶汽车在城市交通系统中的作用及其对现有城市交通结构的影响。[方法]概述了无人驾驶汽车的通行特征,分析了无人驾驶汽车对城市交通结构的影响,详细讨... [目的]探讨无人驾驶汽车技术的发展对未来城市轨道交通可能产生的影响,并分析无人驾驶汽车在城市交通系统中的作用及其对现有城市交通结构的影响。[方法]概述了无人驾驶汽车的通行特征,分析了无人驾驶汽车对城市交通结构的影响,详细讨论了无人驾驶汽车对城市轨道交通的具体影响。[结果及结论]无人驾驶汽车能提高交通效率和乘客体验,可能会导致城市轨道交通短途客流下降,但长途客流对其依赖性仍很强。无人驾驶汽车的普及将促使城市轨道交通规划更注重速度和效率,更注重优化中心城与卫星城间的交通联系方式,也更注重促进各种交通方式信息系统的互通与信息交互,提升城市交通一体化的强度。无人驾驶汽车的发展将引发城市交通的重大变革,需要城市规划者和交通管理者采取相应措施以适应技术发展。 展开更多
关键词 城市轨道交通 无人驾驶汽车 交通规划 出行效率
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