Improving the estimate of wind energy input into the Ekman layer within the Antarctic Circumpolar Current

Based on the data and method offered by Liu et al. （2009）, the direct wind and Stokes drift-induced energy inputs into the Ekman layer within the Antarctic Circumpolar Current （ACC） area are reestimated since the results of the former have been proved to be underestimated. And the result shows that the total rate of energy input into the Ekman-Stokes layer within the ACC area is 852.41 GW, including 649.75 GW of direct wind energy input （76%） and 202.66 GW of Stoke drift-induced energy input （24%）. Total increased energy input, due to wave-induced Coriolis-Stokes forcing added to the classical Ekman model, is 52.05 GW, accounting for 6.5% of the wind energy input into the classical Ekman layer. The long-term variability of direct wind and Stokes drift-induced energy inputs into the Ekman layer within the ACC is also investigated, and the result shows that the Stokes drift hinders the decadal increasing trend of direct wind energy input. Meanwhile, there is a period of 4-5 a in the energy spectrums, as same as the Antarctic circumpolar wave.

Effects of hanging wall and footwall on demand of structural input energy during the 2008 Wenchuan earthquake

Systematic differences in the duration and frequency content of ground motions from the hanging wall and footwall during the 2008 Wenchuan earthquake are investigated,focusing on the influence of these differences on structural input energy based on the elastic and inelastic energy responses of structures.A comparison of the input energy spectra between the hanging wall and the footwall reveal that the structural input energy on the hanging wall is not amplified due to the short duration and low peak ground velocity to acceleration ratio（V/A）.However,the larger demand of structural input energy on the footwall in the range of medium and long periods is observed and the demand increases up to 50% relative to the average level of structural input energy for rupture distances larger than 30 km.The importance of considering the footwall effect on structural input energy when comparing ground motions in the range of medium and long periods is recognized.

Influence of laser energy input mode on joint interface characteristics in laser brazing with Cu-base filler metal

The flange butt joints of 1 mm-thick galvanized steel sheets were brazed with CuSi3 as filler metal at different laser heating modes.The microstructures and element distributions of joint interface were investigated by SEM and EDS.The results show that there is no obvious interface layer with the circular individual beam heating and lamellar Fe-Si intermetallic compound layer is found with dual-beam laser spot heating.With the irradiation of rectangular laser spot,the joint interface layer is also formed.The layer thickness is larger than that of dual-beam brazing and the layer shape is flat so that intermetallic compounds trend to grow into cellular crystals.Moreover,the interface layer shape also depends on its position in the joint.Under the high heat input,dendritic or granular intermetallic compounds dispersively distribute in brazing seam adjacent to the interface,which is caused by the melting or dissolving of the base metal.According to the results,the brazing quality can be controlled by laser heating mode and processing parameters.

Invariant Modulation of IMF Clock Angle on the Solar Wind Energy Input into the Magnetosphere

By use of the global PPMLR Magnetohydrodynamics(MHD) model,a serial of quasisteady-state numerical simulations were conducted to examine the modulation property of the interplanetary magnetic field clock angle θ on the solar wind energy input into the magnetosphere.All the simulations can be divided into seven groups according to different criteria of solar wind conditions.For each group,37 numerical examples are analyzed,with the clock angle varying from 0° to 360° with an interval of 10°,keeping the other solar wind parameters(such as the solar wind number density,velocity,and the magnetic field magnitude) unchanged.As expected,the solar wind energy input into the magnetosphere is modulated by the IMF clock angle.The axisymmetrical bell-shaped curve peaks at the clock angle of 180°.However,the modulation effect remains invariant with varying other solar wind conditions.The function form of such an invariant modulation is found to be sin(0/2)^(2.70) + 0.25.

Study on comparison between absolute and relative input energy spectra and effects of ductility factor

Based on 266 strong ground motion records, an attenuation relationship was developed for both absolute and relative input energy spectra. The comparison of the two kinds of input energy spectra constructed from the attenuation relationship was made in this paper. The results show that there is little difference between the absolute input energy spectra and relative input energy spectra at the periods of 0.5-1.0 s for elastic systems and at the period of 0.5 s for inelastic systems. The absolute input energy spectra are much larger than relative input energy spectra in very short period range but some less than relative input energy spectra in long period range. It is also found that the ductility factor has a significant effect on both absolute and relative input energy spectra. The absolute input energy spectra increase with the increasing of ductility factor in the period range of less than 0.3 s but decrease in the period range of larger than 0.3 s. The absolute input energy spectra for different ductility factor are almost equivalent at the period about 0.3 s, but for relative input energy spectra, the period is about 0.5 s. The effect of ductility on the relative input energy spectra in the short period range is much larger than that on the absolute input energy spectra, especially on the softer site class.

The Influences of Energy Price Variation on the Prices of Other Industries: A Study Based on Input-Output Price Model

Energy has laid material foundation for human society during its development. Meanwhile, any change of price in the energy industry may influence social production and people’s life at all levels via an input-output mechanism under which the change related to energy is surely transmitted to other industries. The price change thus incurred in all industries may adversely affect the realization of macroeconomic objective-maintaining prices at a stable level. It is, therefore, needed to conduct an empirical research related to the impact of price change in energy industry on that in other industries. According to the data coming from “China’s 2015 Input-Output Extension Table (42 Departments)” and four hypothetical basis, this article focuses on four energy sectors and analyzes how deeply the price change of them, by use of input-output model, affects that of other industrial products under five conditions where each of their price rises by 10% individually or simultaneously, and why such an influence occurs. The results show that the price rising of the energies in question leads to an upward growth in the prices of other industrial products, especially when their prices go up simultaneously. Besides, the price increase in the four energy sectors doesn’t influence other industries in an accumulation form but actually leads to a rollback in some of other industries. It is recommended to adopt diversified pricing strategies for different energy products, thus maximizing the value of each specific energy, and meanwhile achieving the goals of energy consumption reduction and price equilibrium.

Meta-analysis of CO_(2) conversion,energy efficiency,and other performance data of plasma-catalysis reactors with the open access PIONEER database

This paper brings the comparison of performances of CO_(2)conversion by plasma and plasma-assisted catalysis based on the data collected from literature in this field,organised in an open access online database.This tool is open to all users to carry out their own analyses,but also to contributors who wish to add their data to the database in order to improve the relevance of the comparisons made,and ultimately to improve the efficiency of CO_(2)conversion by plasma-catalysis.The creation of this database and database user interface is motivated by the fact that plasma-catalysis is a fast-growing field for all CO_(2)conversion processes,be it methanation,dry reforming of methane,methanolisation,or others.As a result of this rapid increase,there is a need for a set of standard procedures to rigorously compare performances of different systems.However,this is currently not possible because the fundamental mechanisms of plasma-catalysis are still too poorly understood to define these standard procedures.Fortunately however,the accumulated data within the CO_(2)plasma-catalysis community has become large enough to warrant so-called“big data”studies more familiar in the fields of medicine and the social sciences.To enable comparisons between multiple data sets and make future research more effective,this work proposes the first database on CO_(2)conversion performances by plasma-catalysis open to the whole community.This database has been initiated in the framework of a H_(2)0_(2)0 European project and is called the“PIONEER Data Base”.The database gathers a large amount of CO_(2)conversion performance data such as conversion rate,energy efficiency,and selectivity for numerous plasma sources coupled with or without a catalyst.Each data set is associated with metadata describing the gas mixture,the plasma source,the nature of the catalyst,and the form of coupling with the plasma.Beyond the database itself,a data extraction tool with direct visualisation features or advanced filtering functionalities has been developed and is available online to the public.The simple and fast visualisation of the state of the art puts new results into context,identifies literal gaps in data,and consequently points towards promising research routes.More advanced data extraction illustrates the impact that the database can have in the understanding of plasma-catalyst coupling.Lessons learned from the review of a large amount of literature during the setup of the database lead to best practice advice to increase comparability between future CO_(2)plasma-catalytic studies.Finally,the community is strongly encouraged to contribute to the database not only to increase the visibility of their data but also the relevance of the comparisons allowed by this tool.

Robust Input-Output Energy Decoupling for Uncertain Singular Systems

This paper addresses the robust input-output energy decoupling problem for uncertain singular systems in which all parameter matrices except E exist as time-varying uncertainties. By means of linear matrix inequalities (LMIs), sufficient conditions are derived for the existence of linear state feedback and input transformation control laws, such that the resulting closed-loop uncertain singular system is generalized quadratically stable and the energy of every input controls mainly the energy of a corresponding output, and influences the energy of other outputs as weakly as possible. Keywords Uncertain singular systems - generalized quadratical stability - input-output energy decoupling - linear matrix inequality (LMI) Xin-Zhuang Dong graduated from the Institute of Information Engineering of People’s Liberation Army, China, in 1994. She received the M. S. degree from the Institute of Electronic Technology of People’s Liberation Army, in 1998 and the Ph.D. degree from Northeastern University, China, in 2004. She is currently a post-doctoral fellow at the Key Laboratory of Systems and Control, CAS.Her research interests include singular and nonlinear systems, especially the control of singular systems such as H ∞ control, passive control and dissipative control. Qing-Ling Zhang received the Ph.D. degree from Northeastern University, China, in 1995. He is currently a professor with the Institute of Systems Science, Northeastern University. His research interests include singular systems, fuzzy systems, decentralized control, and H 2/H ∞ control.

基于输入均压与虚拟直流电机相结合的直流电能路由器控制策略

针对中压直流配电网接入下的直流电能路由器在新能源出力等工况下,使用传统控制策略对直流母线的控制效果一般、电压易越限等问题,基于模块化的输入串联输出并联(input-series output-parallel,ISOP)型拓扑结构,提出一种基于输入均压与虚拟直流电机相结合的直流电能路由器控制策略。首先,研究输入均压控制过程中模块间的功率均衡控制特性并与输出均流控制进行比较;接着,将虚拟直流电机控制应用到控制算法中,使变流器模拟出直流电机的惯性特性;然后,对虚拟直流电机建立小信号数学模型,分析其工作机理以及参数对系统的影响;最后,在MATLAB/Simulink中搭建仿真模型进行验证。结果表明:所提控制策略能够在实现直流电能路由器各模块间功率均衡的同时,具有类似直流电机的惯量特性与阻尼特性,可显著提高直流配电网直流母线电压稳定性。

用于射频能量收集的低阈值CMOS整流电路设计

基于TSMC 180 nm工艺,设计了一款高效率低阈值整流电路。在传统差分输入交叉耦合整流电路的基础上,提出源极与衬底之间增加双PMOS对称辅助晶体管配合缓冲电容的改进结构,对整流晶体管进行阈值补偿。有效缓解了MOS管的衬底偏置效应,降低了整流电路的开启阈值电压,针对较低输入信号功率,提高了整流电路的功率转换效率(PCE)。同时将低阈值整流电路三级级联以提高输出电压。测试结果显示,在输入信号功率为-14 dBm@915 MHz时,三级级联低阈值整流电路实现了升压功能,能稳定输出1.2 V电压,峰值PCE约为71.32%。相较于传统结构,该低阈值整流电路更适合用于射频能量收集。

协同创新中知识距离对知识融合过程的门槛效应研究——以新能源行业为例

从协同主体间知识距离视角,采用Hansen面板门槛模型,构建不同知识距离下知识基础与知识投入影响知识融合的门槛模型,并基于2015-2020年中国新能源行业上市公司面板数据进行实证分析。结果表明,知识距离在知识基础、知识投入影响知识融合的过程中均存在双重门槛效应。其中,随着知识距离扩大,知识基础宽度对知识融合具有“抑制-促进-抑制”的作用效果,且在高知识距离下抑制作用显著增强;知识基础深度对知识融合呈现出“促进-抑制”的作用效果;在知识距离的作用下知识投入对知识融合存在倒U型作用。因此,在协同创新中,组织应选择资源互补且领域相关的合作伙伴,以在融合过程中最大化激发组织知识潜能,促进新知识产生,提高组织创新能力。

新能源企业技术创新投入对全要素生产率的影响——基于融资约束和政府补助视角

选用沪深A股2009—2022年新能源企业的面板数据,采用主成分分析和固定效应模型,经过回归分析后发现:新能源企业技术创新投入与全要素生产率呈现U型关系,这意味着只有当技术创新投入超过极值点时才会促进全要素生产率的提升;融资约束对全要素生产率的提升具有抑制作用;政府补助能调节融资约束对技术创新投入与全要素生产率的抑制作用,使全要素生产率得到提升。建议新能源企业增加技术创新投入或积极获取政府补助,以降低融资约束带来的压力,从而实现全要素生产率的提升。

基于SWIPT的无小区大规模MIMO-NOMA系统能量效率研究

无小区大规模多输入多输出(Multiple-Input Multiple-Output,MIMO)与非正交多址接入(Non-Orthogonal Multiple Access,NOMA)都是未来6G的使能技术。无线携能通信(Simultaneous Wireless Information and Power Transfer,SWIPT)技术在进行信息解码的同时收集能量,与无小区大规模MIMO-NOMA优势互补。文中基于SWIPT研究无小区大规模MIMO-NOMA系统中的能量效率问题,通过联合优化功率分配系数和SWIPT的时隙切换(Time Switching,TS)系数,提高系统的能量效率。为了最大化能量效率,采用布谷鸟算法设计功率分配系数。考虑一种特殊情况,将所有终端的TS系数设置相同,进而推导了最佳TS系数的封闭表达式。仿真结果表明,相较于几种已有方案,文中提出的优化方案可以显著提升系统的能量效率。

基于模糊DEMATEL-超效率DEA的可再生能源发电技术综合效益评估方法

“双碳”目标下,各类可再生能源发电技术发展迅速,综合权衡不同可再生能源发电方案的综合效益对可再生能源的优化设计具有重要意义。综合考虑经济效益、环境效益、能源效益和社会效益4个层面,提出了一种基于模糊决策试验和评价实验(decision making trial and evaluation laboratory,DEMATEL)与超效率数据包络分析(data envelopment analysis,DEA)模型的可再生能源发电技术综合效益评估方法。该方法分为投入-产出指标体系构建和综合评估2个阶段。首先,利用三角直觉模糊数处理模糊评价信息,将其与DEMATEL相结合量化各指标之间相互影响关系,基于指标间逻辑分析结果建立投入-产出评估指标体系。然后,基于超效率DEA模型对各可再生能源发电方案进行评估排序,结合投入冗余和产出不足分析结果给出各方案的针对性改善建议,以期为进一步选择和确定可再生能源产业发展战略提供参考。最后以某省10类可再生能源发电单元为研究对象,基于所提研究方法进行综合评估和分析,并与多准则妥协解排序法和熵权法进行对比分析,验证了所提方法的有效性。

家用空调器产品监督检验中常见不合格项目解析

制冷量、制冷消耗功率、全年能源消耗效率(APF)和制冷季节能源消耗效率(SEER)、接地措施、连续骚扰(端子电压)这五个项目是家用空气调节器产品在监督检验中常见的不合格项目,本文通过列举具体案例,从标准要求和实测数据等方面,重点分析了导致不合格产生的客观及主观原因,并给出了相应的整改方案,为企业提升认识、完善设计、加强质控、规范制造提供了有效的改进建议,助力企业生产出符合国家标准要求的合格产品。

能量输入对捕收剂-煤泥颗粒吸附率的影响研究

捕收剂油滴与煤泥颗粒的有效碰撞粘附是提高浮选效率的重要前提。为了研究能量输入对油滴-煤泥颗粒吸附率的影响,采用改进式浮选机及单煤油液滴-煤泥颗粒碰撞试验系统,分析了不同能量输入因素下捕收剂动能的改变及其对药剂-煤泥吸附率的作用。结果表明:随着搅拌时间的增加,能量输入持续增多,捕收剂-煤泥吸附率随之增大,达到临界值后逐渐减小,这是由于煤油与颗粒之间的吸附作用属于物理吸附,当二者的吸附逐渐达到饱和状态后,能量持续输入打破了吸附平衡,使吸附的油滴发生脱附,最大吸附率为79.82%,对应搅拌时间为40 s。改变叶轮转速,捕收剂动能也随之改变,随着颗粒和药剂分散度逐渐增大,碰撞概率随之增大,吸附率逐渐提高,当叶轮转速由500 r/min增大至700 r/min时,捕收剂-煤泥吸附率由78.11%增大至79.82%。研究结果从多个可变因素角度出发探究了能量输入对捕收剂油滴-煤泥吸附率的影响,为揭示煤泥调浆机制与开发调控技术提供理论参考。

完全隐含能源与碳强度研究进展综述

节能减排是应对全球气候变暖的重要举措。由于不同国家和地区的经济发展水平存在明显差异,近年来能源与碳强度成为度量节能减排绩效的重要指标,受到了社会各界的广泛关注。在生产端强度控制的基础上,如何从根源上在消费端降低完全隐含能源与碳强度的研究越来越受到重视。针对消费端完全隐含能源与碳强度的研究特征与发展趋势展开综述,结果发现:(1)主要呈现出国家层面研究为主、全球层面研究显著增加、省市层面研究开始出现的特征,且国家或省市层面主要聚焦于中国;(2)相比完全隐含能源强度,现有文献更为关注完全隐含碳强度;(3)研究由不区分终端消费向细分各终端消费发展,隐含在出口中的完全隐含碳强度受到了重点讨论;(4)部分研究侧重于局部,比如深度参与到全球生产网络的部分经济部门或能源消费与碳排放在生产网络中传输的关键层级;(5)进行完全隐含碳强度变动的驱动因素的研究主要基于乘性结构分解分析模型,从时间轴和空间轴展开剖析。现有研究框架未来可以扩展到能源环境相关领域的其他指标。

DFA-ODENets:面向周期多阶段复杂系统的预测仿真框架

部分复杂系统受内外部因素影响在运行时会呈现出周期性的阶段变化,且在不同阶段具有完全不同的动态特性.因此在使用数据驱动方法解决此类系统的预测和仿真问题时,使用单一结构模型难以准确地学习系统在不同阶段的动态特性.本研究提出了基于确定性有限状态机-常微分方程网络的预测仿真框架(DFA-ODENets),以建模周期多阶段系统.该模型由多个ODENet组成,每个ODENet能够从不规则采样的序列数据中学习系统在各个阶段内的动态特性.同时模型集成了基于确定性有限状态自动机思想的阶段转换预测器以实现模型预测时在不同阶段之间自动转换.最后,将DFA-ODENet框架应用于某计算中心制冷系统的预测仿真场景中.模型能够在给定系统运行过程中的服务器负载和环境温度下模拟系统运行过程,并对系统的制冷功率、进气口温度等主要输出变量进行预测.其中,对于制冷系统能耗预测的平均相对误差在5%以内.同时,利用制冷系统仿真模型优化了系统停止制冷时的温度设定值,通过仿真实验表明该优化最高可以节省18%的制冷能耗.

超大规模MIMO阵列可视区域空间分布数据集

可视区域(VR)信息可用于降低超大规模多输入多输出(XL-MIMO)系统传输设计复杂度,但现有理论分析与传输设计多基于简化的VR统计分布模型。为评估分析XL-MIMO在实际物理传播场景中的性能,该文公开了XL-MIMO阵列VR空间分布数据集,其由环境参数设置、射线追踪仿真、天线场强数据预处理和VR判定准则等步骤构建。该数据集针对典型城区无线传播场景,建立了用户位置采样与场强数据、VR数据之间的关联,总数据条目数量达上亿级。进一步对其中VR形态、VR分布进行了可视化展示与分析,并以基于VR的XL-MIMO用户接入协议为例,利用该数据集对其在真实传播场景中的性能进行了仿真,为该数据集的应用提供了典型样例。