Research on the longitudinal protection of a through-type cophase traction direct power supply system based on the empirical wavelet transform

This paper proposes a longitudinal protection scheme utilizing empirical wavelet transform(EWT)for a through-type cophase traction direct power supply system,where both sides of a traction network line exhibit a distinctive boundary structure.This approach capitalizes on the boundary’s capacity to attenuate the high-frequency component of fault signals,resulting in a variation in the high-frequency transient energy ratio when faults occur inside or outside the line.During internal line faults,the high-frequency transient energy at the checkpoints located at both ends surpasses that of its neighboring lines.Conversely,for faults external to the line,the energy is lower compared to adjacent lines.EWT is employed to decompose the collected fault current signals,allowing access to the high-frequency transient energy.The longitudinal protection for the traction network line is established based on disparities between both ends of the traction network line and the high-frequency transient energy on either side of the boundary.Moreover,simulation verification through experimental results demonstrates the effectiveness of the proposed protection scheme across various initial fault angles,distances to faults,and fault transition resistances.

Supply chain management research directions for future development

With the rapid development of electronic commerce, supply chain management is facing more and more new challenges. Therefore, it is particularly important to study the development of clear direction of supply chain. However, the supply chain is composed of different interest subjects, each subject in order to achieve the maximization of their own interests and adopt different measures, is a complex, huge system, has brought the huge challenge to the supply chain management. In this paper, the research on Supply Chain Management in the current situation, characteristics and the modem supply chain management are summarized, and combined with new challenges of supply chain management to predict future research direction is the development of supply chain management, in order to make the supply chain management to the greatest extent satisfy the consumer e-commerce mode increasingly popular.

Direct Supply of Daqing Oil to Harbin

TheoilpipelinefromDaqingtotheHarbinRefinerywasformallyputintooperation,thusputtinganendtothe24-yearlonghistoryofrawoiltransportationbytrain.Nowittakesonly48hourstomaketherawoilrunningfromtheTaobeioilstoreofNo.7PlantunderDaqingPetroleumAdministrationp...

Importance Analysis of a Multi-state System Based on Direct Partial Logic Derivatives and Multi-valued Decision Diagrams

Importance analysis quantifies the critical degree of individual component. Compared with the traditional binary state system,importance analysis of the multi-state system is more aligned with the practice. Because the multi-valued decision diagram( MDD) can reflect the relationship between the components and the system state bilaterally, it was introduced into the reliability calculation of the multi-state system( MSS). The building method,simplified criteria,and path search and probability algorithm of MSS structure function MDD were given,and the reliability of the system was calculated. The computing methods of importance based on MDD and direct partial logic derivatives( DPLD) were presented. The diesel engine fuel supply system was taken as an example to illustrate the proposed method. The results show that not only the probability of the system in each state can be easily obtained,but also the influence degree of each component and its state on the system reliability can be obtained,which is conducive to the condition monitoring and structure optimization of the system.

Geostatistical Studies of Space-Temporal Variation in Selected Quality Parameters in Klodzko Water Supply System （SW Part of Poland）

Selected results of research connected with the development of a （3D） geostatistical hydrogeocbemical model of the Klodzko city area, dedicated to the spatial and time variation in the quality parameters in the Klodzko water supply system （SW part of Poland） have been presented. The research covers the period 2007-2011. Spatial analyses of the variation in three quality parameters, i.e. Fe iron （g/m3） content, Mn manganese （g/m3） content and NI-I4＋ ammonium ion （g/m3） content, were carried out. Spatial and time variation in the parameters was analyzed on the basis of the data （2007-2011）. The input for the studies was the chemical determinations of the quality parameters of water samples taken in the Klodzko water supply system area （also treated water） in different periods of time. These data were subjected to spatial analyses using geostatistical methods. The parameters of the assumed theoretical models of directional semivariograms functions of the studied regionalized variables, were used in the ordinary （block） kriging estimation. Generally, the behaviour of the quality parameters in the Klodzko water supply system has been found to vary in space and time. Thanks to the multivariate spatial analyses some regularities in the variation in the water supply system in the Klodzko city area have been identified. In the considered time interval, the shapes of the directional Fe iron content semivariogram show a tendency to vary periodically. The courses of the directional semivariograms of Mn manganese content and NI-I4＋ ammonium ion content show some tendencies towards directional variation over the passing years. There are visible distinct increasing trends of variability for Mn content and stronger variation are observed for NH4＋ ion content. The kriging estimation results were used to determine the levels of elevated values 2＊ of the water quality parameters in the years 2007-2011 and to forecast these values for the years 2012-2014. The maximum values Z＊ of the quality parameters were stated for the years： 2007, 2008-2009 and 2012 （the decreasing trend in Fe iron content averages Z＊ variation towards the year 2012, the increasing trend in Mn content averages Z＊ variation towards the year 2012 and the increasing trend in NH4＋ ion content averages Z＊ variation towards the years 2008-2009 and then the decreasing trend towards the year 2012）.

Supply Side Management for Cost Optimization in Developing Countries Suffering with Power Outage

In this increasingly growing population especially in the developing countries, it is almost impossible to solve the energy crisis. This has led to the extreme growth of the back up power generation industry such as Diesel generators and home invertors. From the last couple of years the solar PV technology has started to penetrate in these geographies. This paper discusses on the supply side management of the electricity sources available to a consumer to manage his outage and also the over all cost optimization, as the cost of energy from every source is different and it also depends on the load curve, last but not the least also as to what time of the day what source or combination of sources have been used.

辅导员在高校“三全育人”中的角色定位与实现路径

构建全员全过程全方位育人格局是落实立德树人根本任务的内在要求和战略举措。高校辅导员在“三全育人”体系中肩负着重要使命,是全员育人中的主导者、全程育人中的统筹者、全方位育人中的串联者。然而,囿于思想认识、能力素质、边界划分等方面的现实困境问题,真正实现好这一角色担当,还需要从激发内生动力、加大资源供给、明确职责边界等方面持续用力,不断提升新时代辅导员育人能力和水平。

零售商促销努力驱动下供应商入侵决策

引入由单个供应商和单个零售商组成的两级供应链,考虑供应商拥有入侵能力和供应商没有入侵能力两种情形,构建了供应商与零售商之间的价格竞争模型,分析了零售商促销努力驱动下供应商的入侵决策方案.研究发现:供应商形成入侵能力所需的固定成本会对供应商的入侵决策产生影响,有入侵能力的供应商会在一定条件下向零售商承诺不入侵;零售商的促销策略会受供应商入侵能力的影响,选择促销对零售商来说并不总是有利的;零售商促销带来高收益的区域随着促销效率的增加而增加,零售商的促销效率越大,零售商利润也越高.

模块化多电平中压直流变换器的高可靠自供电架构研究

随着大容量中压直流配电技术的迅速发展,模块化多电平直流变换器受到工业界和学术界的广泛关注。然而,实现高可靠的辅助供电是实现直流变换器在中压直流配电场景中应用的关键技术瓶颈之一。为此,提出一种面向模块化多电平中压直流变换器的高可靠自供电系统架构。该架构实现主控制器、子模块等辅电系统的中压直联馈电,从而无需额外低压直流电源,并且大幅提升系统启动速度。基于此架构设计,模块化多电平直流变换器的子模块控制器和旁路开关辅助供电均实现3倍冗余,提高系统容错运行的能力。在子模块电容预充电阶段,提出一种基于辅助电源自主控制的子模块电容均压方法,保证模块化多电平直流变换器可靠预充电。最终通过实验验证所提辅助供电系统架构的可行性。

全面认识产业转移的新特征新模式——基于开放视角下的事实与分析

当前,全球产业链正向本地化、区域化、多元化、绿色化和数字化方向加速重构与调整。在此背景下,美欧等国家和地区陆续推出一系列政策措施,加速产业转移步伐,直接影响到我国的产业链供应链安全稳定。对此,文章利用fDi Markets、UN Comtrade等多个数据库,基于开放视角从来华投资、对外直接投资与中间品贸易三个关键维度对我国产业转移的理论与现状进行深入剖析,并归纳出当前产业转移的四种典型模式,进而在“分类研判”基础上提出“精准施策”的方案。研究发现:第一,在来华投资方面,尚未表现出大规模产业转移,法国等欧洲国家对华投资率先增长,但需警惕美日韩等地区以及电子元件、半导体和汽车设备等产业链较长行业的来华外资下降趋势。第二,在对外投资方面,总体呈现出稳中有进的态势,其中对墨西哥以及共建“一带一路”国家的投资增势最为突出,对电子元件、金属制品、汽车设备等高端制造行业以及矿产资源行业的投资也表现出了持续向好的态势。第三,在中间品贸易方面,近年来我国中间品出口在全球市场中的份额显著提升,其中对越南、印度和泰国等地区的出口比重大幅提高,高技术产品的出口增势也尤为突出。在此基础上,我们进一步归纳提出当前产业转移的四种主要模式:地缘政治驱动型、生产成本驱动型、产业链布局驱动型以及国际合作驱动型。最后,根据不同产业转移模式以及当前的产业转移新特征,提出相应的对策建议,为确保我国产业链供应链韧性与安全提供有益的支撑。

供应链部分整合对再制造产品渠道策略的影响分析

再制造的研究主要聚焦于集中和分散的供应链,但在现实商业实践中部分整合的供应链十分常见。本文分别在无供应链整合、供应链部分前向整合(PFI)和供应链部分后向整合(PBI)三种情况下探讨了再制造产品的销售渠道策略选择问题。研究发现,在无供应链整合和PFI下,直销再制造产品对于制造商而言总是占优策略,但不利于零售商,因而造成制造商赢零售商输(win-lose)的局面。在PBI下,直销再制造产品并不一定是制造商的占优策略,此时根据零售商持有股份的大小可能会出现制造商赢零售商输、双赢、制造商输零售商赢三种结果。当制造商直销再制造产品时,相较于无整合情形,在一定条件下PFI可以形成制造商赢零售商赢(win-win)的双赢局面,而PBI总是造成制造商输零售商赢(lose-win)的局面。从对环境的影响来看,由制造商直销再制造产品比零售商销售更环保,而此时不进行供应链部分整合是最环保的。

考虑物流时效的电商农产品供应链演化博弈研究

针对直播电商背景下农产品供应链中存在的生鲜农产品到货不及时以及消费者购买意向低等问题,对电商平台、物流企业和消费者构建三方演化博弈模型,分析各方的博弈行为和演化稳定策略。根据市场上物流企业存在的时效性较差和较好两种情形,运用MATLAB软件进行数值仿真,探究在不同主播努力水平下影响该动态系统演化趋势及演化稳定策略的关键因素。研究发现:平台押金和物流期望满意值的变化在物流时效性较差时影响物流企业和消费者的策略选择;主播佣金比率和平台增值服务投入与电商平台选择高效运营的概率在物流时效性较好时呈负相关关系;减少消费者增值服务有利于平台长期发展和降本增效。研究结果结合直播电商运营情况对农产品供应链提出建议。

车载逆变电源的设计与实现

为解决车载电源的转化问题,提出一种将汽车车载电源从直流12 V转化为交流220 V的车载逆变电源设计方法。该方法将直流12 V作为输入,通过前级升压和后级逆变2个功率转换电路,得到220 V/50 Hz的正弦交流电压。前级升压电路以SG3525作为主控芯片,采用推挽变换电路拓扑结构,利用高频变压器进行隔离升压,通过设计直流母线电压负反馈电路,避免出现直流母线电压的过压;后级逆变电路以EG8010作为主控芯片,采用全桥拓扑结构和SPWM控制技术,通过设计过压过流保护电路和过温保护电路,避免电路过压和过温。实验结果表明,该车载逆变电源在输入直流电压为(12±1.5) V的范围内均可输出稳定的交流电压(219.5~220.1 V),且整机测试效率保持在97.5%左右,具备良好的参数性能。

面向采购文件的跨模态图片文本命名实体识别

智慧供应链的数智化采购环节能够提高采购工作效率,节省大量人力成本。采购文件中包括大量证照资质等文件,针对其中图片文本中文字排版参差不齐、扫描图像不清晰等问题,设计了基于深度学习的端到端跨模态命名实体识别模型O2V2BLC(OCR-Vector-Bi-LSTM-CRF),从图片文本中识别命名实体。该模型针对光学字符识别技术识别出的图片文本字符,定义连续文本字符边界,将边界内每个文本字符映射为向量,设计双向长短期记忆(Bi-LSTM)网络捕获边界内字符序列的上下文语义,计算字符状态分数矩阵,并通过条件随机场约束字符标记序列规则,获得全局最优标记序列。针对训练集计算命名实体预测误差,动态优化O2V2BLC模型的参数,实现命名实体识别。将该方法应用于采购文件资质类型等图片文本数据,能够有效识别图片中的投标单位、专家姓名、专业名称等命名实体,与条件随机场、隐马尔可夫算法、Bert-Bi-LSTM-CRF模型进行对比,显著提高了实体识别准确率,为智慧供应链的数智化采购提供支持。

不同供电方向激励对多极距组合中梯装置三维激电探测效果的影响

本文基于直流点电源三维非结构有限元数值模拟技术和不完全高斯-牛顿三维反演方法,讨论近些年兴起的多极距组合中梯装置三维激电法不同供电方向激励对探测效果的影响,为中梯装置三维激电测量供电方向的合理选择提供依据。首先,设计了多个不同的三维地电模型,在横向供电(供电方向垂直于构造走向或目标体延伸方向)、纵向供电(供电方向平行于构造走向或目标体延伸方向)、横向和纵向双方向组合供电3种方式下,开展理论模型的三维正反演试算。然后,选取某矿区在这三种方式下获取的三维激电实测数据进行三维反演。最后,对理论模型合成数据和实测数据的三维反演结果及矿区已有地质资料进行综合对比分析。研究结果表明:横向供电、纵向供电、横向和纵向双方向组合供电三种方式激电数据的三维反演结果均能有效反映研究区的岩性分布和构造展布特征;但在揭示研究区的局部异常信息方面,横向和纵向双方向组合供电方式激电数据的三维反演结果展示的异常信息更为丰富、完整,而横向供电或纵向供电单方向供电方式激电数据的三维反演结果揭示的异常信息不完整,有可能漏掉部分有效异常信息。

济南市泉水直饮工艺与建设模式的探索与应用

济南市地下岩溶泉水丰富,富含钾、钠、钙、镁、锶以及偏硅酸盐等对人体有益的矿物元素,但水体总硬度超标,不符合现有高品质饮用水标准的要求。为满足济南市民对高品质饮用水的诉求,从泉水直饮实施的工艺路线层面,通过采用绿色无药剂“多介质过滤、精密过滤、超滤、纳滤和臭氧+紫外线双重消杀”技术处理后,出水经304不锈钢管线循环排布至用户,保证饮水安全同时充分保留泉水水质特色。从泉水直饮实施的建设模式层面,充分结合新建小区、既有小区等需求特点,制定了管线入户式和集中式的供水模式,最后指出泉水直饮是济南城市的特色,更是普惠的民生福祉,将按照济南市市民泉水直饮规划要求因地制宜分阶段分步骤推进。

电力需求侧响应在中国的实践和创新

近年来,中国陆续极端高温天气和用电紧张,对电力保供提出了更高的要求,电力需求侧响应作为电力保供的主要方式,对解决电力紧张、新型电力系统源荷双侧不确定、新能源消纳等问题,以及提高用户用电服务水平和实现“双碳”减排目标意义重大。结合中国现执行的电力需求侧响应政策和创新实践,针对用户端资源不足、政府端体制机制不完善、技术端智能化程度较低、建设端基础建设成本高等问题,从加快市场化运作、挖掘需求响应潜力资源、优化提升体制机制、提升关键技术攻关能力4个层面,为中国未来电力需求侧响应发展提出具体的实践路径。

中国对外直接投资与“一带一路”全球价值链质量

高质量共建“一带一路”背景下,中国对“一带一路”国家直接投资的东道国全球价值链升级效应需向质量效应拓展,然而缺少相关理论分析与实证检验。基于2007-2019年亚洲开发银行编制的世界投入产出表,从效率和稳定性两个方面构建指标并测算“一带一路”国家层面全球价值链质量数据,在此基础上实证分析中国对“一带一路”直接投资的东道国全球价值链质量效应。研究发现:中国对“一带一路”直接投资显著提升了东道国参与全球价值链质量,主要通过提高“一带一路”东道国中间品生产效率、中间品供应稳定性及中国与“一带一路”东道国间生产关联实现;异质性分析发现,中国OFDI的东道国全球价值链质量提升效应在“一带一路”发展中国家、与中国政治互信程度高、与中国拥有共同语言及海上丝绸之路等国家体现得更明显,同时“一带一路”倡议强化了中国对外直接投资的这种提升效应;拓展分析发现,中国对“一带一路”国家直接投资显著提升了东道国参与全球价值链效率和全球价值链稳定性。

老年人照料设施消防应急照明和疏散指示系统设计探讨

以老年人照料设施为例,对其中主要功能用房、走道等区域的消防应急照明和疏散指示系统设计要求进行分析,为设计同行提供一些设计思路。

直接空气捕集选址条件专家问卷调查

直接空气捕集技术(DAC)作为一种从空气中捕集CO_(2)的新兴负排放技术,对实现全球气候目标越来越重要。然而,如何优化DAC选址以支撑其大规模部署亟待解决。基于现有文献资料,构建了一个广泛适用的DAC项目选址指标体系,其中,一级指标可归纳为CO_(2)封存与运输、能源供应、环境特征、社会影响4方面,并覆盖21项二级指标。基于该指标体系,对从事相关领域的政府管理人员、科研人员和产业专家开展问卷调查,评估了各项指标影响DAC选址的重要性。结果表明,DAC选址是一个多因素决策过程,不同因素对不同技术类型的影响程度存在显著差异。针对高温吸收技术,一级指标的重要性依次为环境特征、能源供应、社会影响以及封存与运输;针对低温吸附技术,一级指标的重要性依次为环境特征、社会影响、能源供应以及封存与运输。特别地,温度对高温吸收技术选址至关重要,而土地利用和相对湿度对低温吸附技术尤为关键。此外,专家意见针对一些指标(如空气质量、核能供应)存在显著分歧,表明实际外界条件如何具体影响DAC性能研究尚不充分。未来应进一步加强多因素影响下DAC选址研究,对于实现负碳技术大规模推广具有重要意义。