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基于Power BI的绿色供应链环境成本管理研究 被引量:1
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作者 潘富玲 符丽美 《财会通讯》 北大核心 2025年第2期169-176,共8页
一味追求经济利益而忽略环境因素将不利于企业实现绿色可持续发展目标,同时也与当前国家大力号召的绿色低碳转型产业方向相背离。传统末端治理方法会导致事后阶段环境成本的比重不断增加,进而使企业面临着巨大的双重压力即经济和环境污... 一味追求经济利益而忽略环境因素将不利于企业实现绿色可持续发展目标,同时也与当前国家大力号召的绿色低碳转型产业方向相背离。传统末端治理方法会导致事后阶段环境成本的比重不断增加,进而使企业面临着巨大的双重压力即经济和环境污染治理负担。如何有效提升公司的环境成本管理效率和效果成为环保机构、企业及社会各界关注的重点问题。企业环境成本产生于绿色供应链各环节之中,为进一步提高绿色供应链环境成本管理的透明度、实时性、效率性,引入具有数据集中、数据预处理、结果直观可视化功能的Power BI技术,结合高污染、高耗能的钢铁行业企业展开具体分析。研究发现,利用Power BI实现各供应链环节之中的环境成本情况明晰化,进而通过提升每个环节的绿色化能够有效降低企业环境成本,减少环境污染问题。 展开更多
关键词 绿色供应链 环境成本管理 power BI
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轮式拖拉机静液压驱动PTO变速箱优化设计与验证 被引量:1
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作者 玉立新 《南方农机》 2025年第7期132-135,共4页
【目的】解决现有轮式拖拉机动力输出装置在作业过程中常出现的异响、振动及壳体松动漏油等故障问题,提升拖拉机作业效率及客户产品体验感。【方法】研发了一款静液压驱动PTO变速箱。首先,构建并优化了静液压驱动PTO变速箱传动系统动力... 【目的】解决现有轮式拖拉机动力输出装置在作业过程中常出现的异响、振动及壳体松动漏油等故障问题,提升拖拉机作业效率及客户产品体验感。【方法】研发了一款静液压驱动PTO变速箱。首先,构建并优化了静液压驱动PTO变速箱传动系统动力学模型,设计了变速箱动力传动路线,匹配了齿轮宏观参数,并运用虚拟分析方法进行了齿轮的微观修型;其次,优化设计了变速箱总成壳体结构,并运用ANSYS Workbench分析工具对变速箱壳体进行了结构静力学分析;最后,进行了轮式拖拉机PTO变速箱总成的台架性能试验。【结果】PTO变速箱可实现540 r/min和1 000 r/min两种动力输出转速,能满足整机设计需求。【结论】整个设计过程可以为同类型轮式拖拉机PTO变速箱的开发提供有益借鉴。 展开更多
关键词 轮式拖拉机 静液压 pto变速箱 优化设计
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Microwave power transmission technologies for space solar power station
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作者 YANG Bo SHINOHARA Naoki 《中国空间科学技术(中英文)》 北大核心 2025年第2期1-14,共14页
The microwave wireless power transmission technologies for space solar power station are a crucial field in the international space sector,where various countries are competing in its development.This paper surveys th... The microwave wireless power transmission technologies for space solar power station are a crucial field in the international space sector,where various countries are competing in its development.This paper surveys the research experiments and development efforts related to space solar power stations and microwave wireless power transmission technologies worldwide.The objective is to assess the progress and current state of this technological foundation,determine the necessary focus for developing high-power microwave wireless power transmission technology,and provide clarity on the direction of future technology development in these areas.Finally,a distributed space solar power station plan that is immediately feasible is proposed. 展开更多
关键词 microwave power transmission space solar power station wireless power transfer microwave transmitter phased array rectenna array
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An optimal design of the liquid-cooling plate channel in a power battery based on response surface methodology
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作者 Jinbo Zheng Jibin Jiang +2 位作者 Xiwei Yu Bingjun Yan Guofu Lian 《中国科学技术大学学报》 北大核心 2025年第2期52-65,51,I0002,共16页
The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the rel... The work takes a new liquid-cooling plate in a power battery with pin fins inside the channel as the object.A mathematical model is established via the central composite design of the response surface to study the relationships among the length,width,height,and spacing of pin fins;the maximum temperature and temperature difference of the battery module;and the pressure drop of the liquid-cooling plate.Model accuracy is verified via variance analysis.The new liquid-cooling plate enables the power battery to work within an optimal temperature range.Appropriately increasing the length,width,and height and reducing the spacing of pin fins could reduce the temperature of the power battery module and improve the temperature uniformity.However,the pressure drop of the liquid-cooling plate increases.The structural parameters of the pin fins are optimized to minimize the maximum temperature and the temperature difference of the battery module as well as the pressure drop of the liquid-cooling plate.The errors between the values predicted and actual by the simulation test are 0.58%,4%,and 0.48%,respectively,which further verifies the model accuracy.The results reveal the influence of the structural parameters of the pin fins inside the liquid-cooling plate on its heat dissipation performance and pressure drop characteristics.A theoretical basis is provided for the design of liquid-cooling plates in power batteries and the optimization of structural parameters. 展开更多
关键词 response surface methodology power battery cooling channel optimal design
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Performance analysis of scramjet including magnetohydrodynamic power generation after combustor
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作者 LIU Chenyuan WU Shaoxun MENG Hao 《推进技术》 北大核心 2025年第8期15-28,共14页
To investigate the overall performance of reverse energy bypass scramjet,firstly a variable spe⁃cific heat method combined with a chemical balance calculation module for combustion products were used to es⁃tablish a b... To investigate the overall performance of reverse energy bypass scramjet,firstly a variable spe⁃cific heat method combined with a chemical balance calculation module for combustion products were used to es⁃tablish a benchmark scramjet performance evaluation model.Based on the test data of typical flying point of Mach 7 with the altitude of 29 km,the reliability of the model was verified.The deviations of parameters such as the to⁃tal pressure loss of combustor between the model and the test data were analyzed.Furtherly,an analytical method for post-combustion magnetohydrodynamic power generation was established;by embedding the above method into the overall performance evaluation model,performance prediction considering the power generation effect was realized.Finally,based on the above model,variety regulations of the inlet and the outlet parameters of the power generation channel and performance parameters including the engine specific impulse and the unit thrust under different enthalpy extraction ratios and load factors were analyzed.It could be concluded that the model can reliably predict the variations of key parameters.As the value of the load factor increases,the value of the conduc⁃tivity required to reach the specified enthalpy extraction ratio first decreases and then increases,which is approxi⁃mately parabolic.In order to reduce the demand for the gas conductivity for MHD power generation,the load fac⁃tor should be around 0.5.When the load factor is 0.4 and the magnetic induction intensity is 2.5 T,if the enthalpy extraction ratio reaches 0.5%,the engine specific impulse performance reduces about 3.58%. 展开更多
关键词 SCRAMJET Energy bypass Magnetohydrodynamic power generation Chemical balance Performance evaluation
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A class of quasilinear equations with-1 powers
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作者 ZHANG Heng SUN Yijing 《中国科学院大学学报(中英文)》 北大核心 2025年第1期13-19,共7页
This paper deals with quasilinear elliptic equations of singular growth like-Δu-uΔ(u^(2))=a(x)u^(-1).We establish the existence of positive solutions for general a(x)∈L^(p)(Ω),p>2,whereΩis a bounded domain inℝ... This paper deals with quasilinear elliptic equations of singular growth like-Δu-uΔ(u^(2))=a(x)u^(-1).We establish the existence of positive solutions for general a(x)∈L^(p)(Ω),p>2,whereΩis a bounded domain inℝ^(N)with N≥1. 展开更多
关键词 quasilinear singular equation -1 power elliptic equation
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基于缓速器加载的移动式PTO功率试验台研发
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作者 王露 李华雷 +3 位作者 赵亚燊 唐鑫林 刘小锋 胡豪 《农业工程》 2025年第7期101-105,共5页
介绍一种可移动式动力输出轴(PTO)功率试验台,适用于野外试验测试、生产线末端检测、农机维修站等多种场景。试验台以电涡流缓速器为加载单元,配合分动箱实现加载功能,以满足拖拉机多种工作场景下的动力输出轴功率测试。该试验台具有体... 介绍一种可移动式动力输出轴(PTO)功率试验台,适用于野外试验测试、生产线末端检测、农机维修站等多种场景。试验台以电涡流缓速器为加载单元,配合分动箱实现加载功能,以满足拖拉机多种工作场景下的动力输出轴功率测试。该试验台具有体积小、质量小、适应性强及加载稳定可靠的特点。 展开更多
关键词 拖拉机 动力输出轴 可移动式 电涡流缓速器 功率试验台
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Discussion on Methods and Influence Factors for Minimum Propulsion Power Assessment
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作者 ZHAN Xing−yu MAO Xiao−fei LI Ting−qiu 《船舶力学》 北大核心 2025年第6期888-900,共13页
Currently,the International Maritime Organization(IMO)has approved and implemented the assessment requirement for Minimum Propulsion Power(MPP)of ships in adverse sea conditions.The assessment method and relevant infl... Currently,the International Maritime Organization(IMO)has approved and implemented the assessment requirement for Minimum Propulsion Power(MPP)of ships in adverse sea conditions.The assessment method and relevant influence factors will have a vital impact on ship's design and operation.On the other hand,MPP is essentially a criterion for manoeuvring safety at actual seas.However,the practical assessment methods adopted in IMO guidelines do not directly and accurately account for ship's coursekeeping ability in severe seas.A time-domain comprehensive method with supplementary course-keeping ability criteria has been proposed in the authors'preliminary research.Based on an updated mathematical model and criteria,this paper presents more detailed elaborations,results and discussions on the time-domain method,including the comparative analyses with a power line method and two steady-state equilibrium methods based on IMO guidelines and draft.Discussions on the influences of key factors,involving criterion conditions and calculation parameters,are also presented.The results indicate that different methods exhibit varying advantages and complexity in MPP assessment,thus constituting a multi-level assessment framework for MPP.In particular,the time-domain comprehensive assessment has a higher accuracy with more realistic description of manoeuvre behaviors,capable of offering a solution for the ships that cannot meet other assessments,or for the assessment requiring additional course-keeping ability.Furthermore,an expanded range of wave direction sets a stricter but potentially necessary requirement,while using the self-propulsion factors at low speeds can eliminate the unnecessary conservation of assessment result caused by those at design speed. 展开更多
关键词 manoeuvrability in actual seas minimum propulsion power comprehensive assessment manoeuvrability criterion course keeping
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Study, development and related application of a miniature compact pulsed power supply with high repetition frequency
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作者 Zhangfei Wang Jian Liu +1 位作者 Chunxia Yang Baoming Li 《Defence Technology(防务技术)》 2025年第5期304-318,共15页
Capacitor-based pulsed power supply(PPS)is widely used in fields related to electromagnetic launch,plasma,and materials'synthesis,modification and processing.As industrial applications place higher requirements on... Capacitor-based pulsed power supply(PPS)is widely used in fields related to electromagnetic launch,plasma,and materials'synthesis,modification and processing.As industrial applications place higher requirements on compact and portable pulsed power supplies,the National Key Laboratory of Transient Physics(NKLTP)recently developed a pulsed power supply consisting of a set of compact pulse-forming units(PFU),each with a capacitor energy storage of 220 kJ.This integrated PPS comes with a complete system configuration,a miniature compact structure,a high rate of repetition,and high power,with energy storage density exceeding 1.2 MJ/m^(3).This paper describes the device-level design of the unit,the system layout,the control system,the thermal management system,and the experimental results of the pulsed power supply.The experimental results verified the good reliability of the PPS at high repetition rates with each unit module delivering an output current of more than 100 kA.Additionally,flexible current pulse shapes can be formed by setting the charging voltage and the trigger sequence of the PFUs.The pulse forming network(PFN)developed from these PFUs was successfully applied to electromagnetic launch. 展开更多
关键词 Electromagnetic railgun Pulsed power supply Energy storage density Thermal management system Precision control system
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Optimal Receiver Operating Characteristic Curve of Classical Conditional Power under Normal Models
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作者 ZHANG Ying-Ying 《应用概率统计》 北大核心 2025年第2期277-304,共28页
A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment ... A Receiver Operating Characteristic(ROC)analysis of a power is important and useful in clinical trials.A Classical Conditional Power(CCP)is a probability of a classical rejection region given values of true treatment effect and interim result.For hypotheses and reversed hypotheses under normal models,we obtain analytical expressions of the ROC curves of the CCP,find optimal ROC curves of the CCP,investigate the superiority of the ROC curves of the CCP,calculate critical values of the False Positive Rate(FPR),True Positive Rate(TPR),and cutoff of the optimal CCP,and give go/no go decisions at the interim of the optimal CCP.In addition,extensive numerical experiments are carried out to exemplify our theoretical results.Finally,a real data example is performed to illustrate the go/no go decisions of the optimal CCP. 展开更多
关键词 area under the curve(AUC) classical conditional power(CCP) go/no go decisions historical and interim data receiver operating characteristic(ROC)curve
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拖拉机PTO湿式离合器控制阀的分析及改进 被引量:3
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作者 宋国风 裴高院 +3 位作者 赵鑫 陈静芳 杜东辉 朱晓宇 《拖拉机与农用运输车》 2024年第5期65-68,共4页
主要对几种常用的拖拉机PTO湿式离合器控制阀块进行了简单介绍,并针对拖拉机PTO湿式离合器控制阀块的工作原理及存在问题进行分析,提出一种性能更优的PTO湿式离合器电比例控制阀块。此控制阀块结构紧凑,冲击小,散热效果好,系统能耗较低... 主要对几种常用的拖拉机PTO湿式离合器控制阀块进行了简单介绍,并针对拖拉机PTO湿式离合器控制阀块的工作原理及存在问题进行分析,提出一种性能更优的PTO湿式离合器电比例控制阀块。此控制阀块结构紧凑,冲击小,散热效果好,系统能耗较低,且可实现湿式离合器的柔性结合。 展开更多
关键词 拖拉机 pto 离合器 电比例
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Power-V诱导的钻柱黏滑振动特征分析
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作者 王文昌 段浩宇 +2 位作者 李宁 王孝亮 狄勤丰 《上海大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期299-307,共9页
黏滑是石油钻井过程中影响钻井效率和井下钻柱安全的一种振动形式.垂直钻井系统Power-V在提供有效控斜力的同时,还会诱导钻柱黏滑振动.通过研究垂直钻井系统Power-V与井壁的接触作用及钻头与地层的相互作用模型,基于钻柱动力学有限元方... 黏滑是石油钻井过程中影响钻井效率和井下钻柱安全的一种振动形式.垂直钻井系统Power-V在提供有效控斜力的同时,还会诱导钻柱黏滑振动.通过研究垂直钻井系统Power-V与井壁的接触作用及钻头与地层的相互作用模型,基于钻柱动力学有限元方法,深入分析Power-V的作用机理,研究其对扭转振动的影响,指出Power-V和井壁间的相互作用会导致钻柱与井壁的摩阻显著增加,进而引起摩阻扭矩的增大,诱导井下黏滑振动.实测振动数据证实,Power-V与井壁间的相互作用是引起钻柱黏滑振动的关键因素.这对于揭示黏滑振动的成因和更好地发挥Power-V的作用具有重要意义. 展开更多
关键词 黏滑振动 钻柱动力学 振动信号测量 power-V
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Asymptotically Optimal Scenario Analysis and Wait-and-See Model for Optimal Power Flow With Wind Power 被引量:27
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作者 LI Jinghua WEI Hua MO Dong 《中国电机工程学报》 EI CSCD 北大核心 2012年第22期I0003-I0003,共1页
精确模拟风功率分布的场景,有效求解反映风电随机性的最优潮流模型,对大规模风电并网的经济调度、质量控制及安全运行均具有重要意义。引入风电随机变量,建立最优潮流的"wait-and-see"(WS-OPF)模型;采用优于其他指标的瓦瑟斯坦(Was... 精确模拟风功率分布的场景,有效求解反映风电随机性的最优潮流模型,对大规模风电并网的经济调度、质量控制及安全运行均具有重要意义。引入风电随机变量,建立最优潮流的"wait-and-see"(WS-OPF)模型;采用优于其他指标的瓦瑟斯坦(Wasserstein)距离为衡量指标,形成与风功率概率分布最优近似的场景模型,生成渐近最优场景,获得潮流分布及机组最优出力等指导调度安全经济运行的重要信息。最后,以IEEE 30和IEEE 300系统为例,对比各种距离指标的模拟精度,验证Wasserstein距离的优良性;同时,与不考虑风电随机性的模型相比,WS-OPF模型能更好地模拟风功率随机特性,提供与实际发生的风功率相近的调度方案,从而合理地规避风电接入电网的风险,提高风电的消纳能力。 展开更多
关键词 优化调度模型 渐近最优 最优潮流 风电 随机变量 电力系统
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基于液压加载的拖拉机PTO测试装置设计与试验 被引量:2
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作者 胡豪 张盼港 +2 位作者 潘华磊 赵亚燊 周豫鸽 《农业工程》 2024年第5期83-88,共6页
针对当前多数负荷车仅适用于拖拉机牵引试验测试,模拟完整田间作业状态不全面的现状,设计了一种可挂接负荷车的液压加载式拖拉机动力输出轴(PTO)测试装置,在满足负荷车牵引试验国家标准要求的基础上可以进行拖拉机PTO测试试验。该测试... 针对当前多数负荷车仅适用于拖拉机牵引试验测试,模拟完整田间作业状态不全面的现状,设计了一种可挂接负荷车的液压加载式拖拉机动力输出轴(PTO)测试装置,在满足负荷车牵引试验国家标准要求的基础上可以进行拖拉机PTO测试试验。该测试装置采用的液压测功机与应用普遍的直流电力测功机经过试验对比,系统响应和稳定速度更快,综合加载性能更好。对该测试装置进行拖拉机PTO田间转矩载荷谱模拟动态加载试验,结果表明,实际加载转矩与转矩载荷谱试验数据相关性良好,拟合优度0.83。数据分析得出,计算实际液压加载系统响应时间约2.1 s,最大超调量7.52%,均在可控范围内,说明该测试设备可以通过输入转矩载荷谱的形式有效模拟田间作业拖拉机PTO工作状态,为后续拖拉机牵引及转矩全面加载田间模拟试验提供参考。 展开更多
关键词 拖拉机 液压加载 动力输出轴 负荷车 转矩载荷谱
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Research on Verification Method of Motor Startups in Nuclear Power Plants Based on Topology Recognition
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作者 Li Baozhu Dong Weijie Chen Chao 《系统仿真学报》 CAS CSCD 北大核心 2024年第12期2813-2823,共11页
There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive softw... There are many motors in operation or on standby in nuclear power plants,and the startup of group motors will have a great impact on the voltage of the emergency bus.At present,there is no special or inexpensive software to solve this problem,and the experience of engineers is not accurate enough.Therefore,this paper developed a method and system for the startup calculation of group motors in nuclear power plants and proposed an automatic generation method of circuit topology in nuclear power plants.Each component in the topology was given its unique number,and the component class could be constructed according to its type and upper and lower connections.The subordination and topology relationship of switches,buses,and motors could be quickly generated by the program according to the component class,and the simplified direct power flow algorithm was used to calculate the power flow for the startup of group motors according to the above relationship.Then,whether the bus voltage is in the safe range and whether the voltage exceeds the limit during the startup of the group motor could be judged.The practical example was used to verify the effectiveness of the method.Compared with other professional software,the method has high efficiency and low cost. 展开更多
关键词 power supply for nuclear power plant automatic topology recognition startup of group motor simplified direct power flow algorithm verification method
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A review on recent development of space solar power
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作者 HOU Xinbin MANKINS John +2 位作者 SHINOHARA Naoki CHOI Joon-Min SOLTAU Martin 《中国空间科学技术(中英文)》 CSCD 北大核心 2024年第6期33-51,共19页
Space solar power(SSP)system,a major type of space-based power-generating equipment,is an important infrastructure providing massive,continuous,and stable green electricity by utilizing solar energy in space.Many coun... Space solar power(SSP)system,a major type of space-based power-generating equipment,is an important infrastructure providing massive,continuous,and stable green electricity by utilizing solar energy in space.Many countries and organizations consider SSP to be one of the most promising clean energy sources.The historical activities of SSP in the world are summarized.This review focuses on the significant development of SSP during the last 10 years,which is the most important period for SSP.The latest international SSP development programmes in the United States,ESA,Japan,China,UK and Korea are presented.Some significant solar power satellite(SPS)concepts proposed in the decade,including typical SPS-ALPHA,MR-SPS,CASSIOPeiA SPS,et al.,are introduced.The technical and non-technical challenges are also listed and several important in-space demonstration missions in recent years and in the near future are introduced.The conclusion is that the next 5 to 10 years will be an important period for rapidly developing the key technologies and conducting on-orbit demonstration and application.Controlling the mutual position relationship between the solar array and the transmitting antenna becomes a core issue to be considered in the innovative design of the SPS.Wireless power transmission technologies would be the demonstration focus for the first step.It is expected that the first commercial SPS would be constructed as early as 2040. 展开更多
关键词 space solar power solar power satellite REVIEW STRATEGY DEMONSTRATION
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Comparison of the Overall CO_(2) Emissions of Different Powertrain Systems Depending on the Energy Sector Emissions
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作者 Tobias STOLL Hans-Jürgen BERNER AndréCASAL KULZER 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第S01期46-50,共5页
A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defoss... A circular and sustainable economy for the private transport sector requires a holistic view of the emitted CO_(2) emissions.Looking at the energy supplied to the vehicle in terms of a circular economy leads to defossilisation.The remaining energy sources or forms are renewable electric energy,green hydrogen and renewable fuels.A holistic view of the CO_(2) emissions of these energy sources and forms and the resulting powertrain technologies must take into account all cradle-to-grave emissions for both the vehicle and the energy supply.In order to compare the different forms of energy,the three most relevant forms of powertrain technology are considered and a configuration is chosen that allows for an appropriate comparison.For this purpose,data from the FVV project“Powertrain 2040”are used[1]and combined with research data on the energy supply chain for passenger cars.The three comparable powertrain configurations are a battery electric vehicle,a fuel cell electric vehicle and an internal combustion engine hybrid vehicle fueled with electric fuel.First,the three selected powertrain configurations are presented in terms of their performance,weight,technology and other characteristics.A comparative analysis is carried out for different CO_(2) emissions of the electricity mix.The electricity mix is used for both the production of the vehicle and the energy.The results are presented in the form of cradle-to-wheel emissions,which consider the total CO_(2) emissions of the vehicle over its life cycle.Finally,the results are analyzed and discussed to determine which powertrain technology fits best into which energy sector CO_(2) emissions window. 展开更多
关键词 VEHICLES energy supply power system carbon emission
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电力多元转换(Power-to-X):技术路径、应用与挑战 被引量:5
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作者 李亚楼 王丹丹 +1 位作者 赵飞 李芳 《电网技术》 EI CSCD 北大核心 2024年第5期1809-1820,I0001,共13页
碳中和目标驱动下,新能源装机比重迅速提升,但其随机性与波动性将给电力系统消纳和安全运行带来巨大挑战。电力多元转换(Power-to-X)可以将可再生能源发电转换为其他各类绿色燃料,利用化学能实现对电能的吸收、储存和运输,为电力系统电... 碳中和目标驱动下,新能源装机比重迅速提升,但其随机性与波动性将给电力系统消纳和安全运行带来巨大挑战。电力多元转换(Power-to-X)可以将可再生能源发电转换为其他各类绿色燃料,利用化学能实现对电能的吸收、储存和运输,为电力系统电能储存和利用提供了新思路;同时,通过电力多元转换,也加强了各种能源形式的耦合,降低了不同领域的碳排放,对推进我国绿色低碳转型具有重要意义。该文着重介绍了Power-to-X涉及的各个关键环节,包括电解制储氢、碳捕集以及绿氢转换的技术发展现状;重点比较了4类典型Power-to-X路径——电转甲烷、电转甲醇、电转醚类和电转氨的技术流程;此外,该文针对当前国内外Power-to-X实施情况,具体介绍了各类示范项目的应用进展;进一步地,该文从能效、碳源以及制氢技术等方面出发,剖析了Power-to-X发展面临的主要问题与挑战;最后,针对当前问题,该文提出了相应应对措施,并对Power-to-X的未来发展进行了展望。 展开更多
关键词 可再生能源 电力多元转换 电解制氢 绿氢转换 绿色燃料
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Modified multiple-component scattering power decomposition for PolSAR data based on eigenspace of coherency matrix
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作者 ZHANG Shuang WANG Lu WANG Wen-Qing 《红外与毫米波学报》 SCIE EI CAS CSCD 北大核心 2024年第4期572-581,共10页
A modified multiple-component scattering power decomposition for analyzing polarimetric synthetic aperture radar(PolSAR)data is proposed.The modified decomposition involves two distinct steps.Firstly,ei⁃genvectors of ... A modified multiple-component scattering power decomposition for analyzing polarimetric synthetic aperture radar(PolSAR)data is proposed.The modified decomposition involves two distinct steps.Firstly,ei⁃genvectors of the coherency matrix are used to modify the scattering models.Secondly,the entropy and anisotro⁃py of targets are used to improve the volume scattering power.With the guarantee of high double-bounce scatter⁃ing power in the urban areas,the proposed algorithm effectively improves the volume scattering power of vegeta⁃tion areas.The efficacy of the modified multiple-component scattering power decomposition is validated using ac⁃tual AIRSAR PolSAR data.The scattering power obtained through decomposing the original coherency matrix and the coherency matrix after orientation angle compensation is compared with three algorithms.Results from the experiment demonstrate that the proposed decomposition yields more effective scattering power for different PolSAR data sets. 展开更多
关键词 PolSAR data model-based decomposition eigenvalue decomposition scattering power
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Numerical simulation on magnetohydrodynamic power generation channel of scramjet
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作者 LING Wenhui WU Shaoxun +2 位作者 ZHANG Yining LIU Chenyuan MENG Hao 《推进技术》 EI CAS CSCD 北大核心 2024年第11期255-268,共14页
The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distanc... The reverse magnetohydrodynamic(MHD)energy bypass technology is a promising energy redis⁃tribution technology in the scramjet system,in augmented with a power generation equipment to supply the neces⁃sary long-distance flight airframe power.In this paper,a computational model of the scramjet magnetohydrody⁃namic channel is developed and verified by using the commercial software Fluent.It is found that when the mag⁃netic induction intensity is 1,2,3,4 T,the power generation efficiency is 22.5%,22.3%,22.0%,21.5%,and decreases with the increase of the magnetic induction intensity,and the enthalpy extraction rate is 0.026%,0.1%,0.21%,0.34%,and increases with the increase of the magnetic induction intensity.The deceleration ef⁃fect of electromagnetic action on the airflow in the power channel increases with the increase of magnetic induc⁃tion intensity.The stronger the magnetic field intensity,the more obvious the decreasing effect of fluid Mach num⁃ber in the channel.The power generation efficiency decreases as the magnetic induction intensity increases and the enthalpy extraction rate is reversed.As the local currents gathering at inlet and outlet of the power generation area,total temperature and enthalpy along the flow direction do not vary linearly,and there are maximum and minimum values at inlet and outlet.Increasing the number of electrodes can effectively regulate the percentage of Joule heat dissipation,which can improve the power generation efficiency. 展开更多
关键词 SCRAMJET MAGNETOHYDRODYNAMICS power generation channel Ionized seeds Numerical simulation
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