HIL testing of wheel slide protection systems:criteria for continuous updating and validation

Assessment of railway wheel slide protection(WSP) systems involves the execution of complex experimental activities that are quite expensive and time-consuming, since they involve the physical reproduction of degraded adhesion conditions on a real railway line. WSP is devoted to regulating applied braking forces to avoid excessive wheel sliding in case of degraded adhesion conditions between wheel and rail. WSP must be also compliant to safety specifications related to assured braking performances and consumed air. Hardware in the loop(HIL) testing offers an affordable and sustainable way to accelerate these activities optimizing cost, duration and safety of experimental activities performed online. HIL test rigs are subjected to continuous updates, customization and natural ageing of their components. This work investigates the criteria that can be adopted to assure a continuous monitoring and validation of a real WSP test rig, the Italian test rig of Firenze Osmannoro.

Liver protection strategies in liver transplantation

BACKGROUND： Liver transplantation is the therapy of choice for patients with end-stage liver diseases. However, the gap between the low availability of organs and high demand is continuously increasing. Innovative strategies for organ protection are necessary to expand donor pool and to achieve better outcomes for liver transplantation. The present review analyzed and compared various strategies of liver protection.DATA SOURCES： Databases such as PubM ed, Embase and Ovid were searched for the literature related to donor liver protection strategies using following key words： ＂ischemia reperfusion injury＂, ＂graft preservation＂, ＂liver transplantation＂, ＂machine perfusion＂ and ＂conditioning＂. Of the 146 studies identified,only those with cutting edge strategies were analyzed.RESULTS： A variety of therapeutic approaches were proposed to alleviate graft ischemia/reperfusion injury, which included static cold storage, machine perfusion （hypothermic, normothermic and subnormothermic）, manual conditioning （pre,post and remote）, and pharmacological conditioning. Evidences from animal experiments and clinical trials suggested that all these strategies could potentially protect liver graft; however, their clinical applications are limited partially due to their own disadvantages.CONCLUSIONS： There are a plenty of methods suggested to decrease the degree of donor liver transplantation-related injury. However, none of these approaches is perfect in clinical practice. More translational researches （molecular and clinical studies） are needed to improve the techniques in liver graft protection.

Research on Hidden Failure Reliability Modeling of Electric Power System Protection

Aiming at digital relay protection system, a novel hidden failure Markov reliability model is presented for a single main protection and double main protection systems according to hidden failure and protection function under Condition-Based Maintenance (CBM) circumstance and reliability indices such as probability of protection system hidden failure state are calculated. Impacts of different parameters (containing impacts of human errors) to hidden failure state probability and the optimal measures to improve reliability by variable parameter method are also analyzed. It’s demonstrated here that: Compared to a single main protection, double main protection system has an increased hidden failure probability, thus the real good state probability decreases, two main protections’ reliability must be improved at the same time, so configuration of the whole protection system for the component being protected can’t be complicated. Through improving means of on-line self-checking and monitoring system in digital protection system and human reliability, the real application of CBM can decrease hidden failure state probability. Only through this way can we assure that the protection systems work in good state. It has a certain reference value to protection system reliability engineering.

A Design of 220 kV Line Protection Action Deduction System Based on Numerical Simulation

Accurate conditions monitoring and early wrong action warnings of relay protection in the Smart Substation is the basic guarantee to realize the normal operation of primary and secondary system of the power grid.At present,the traditional operation and maintenance monitoring methods of relay protections have poor timeliness,while some automatic monitoring methods have insufficient early warning performance,and lack the online action deduction function independent of the actual device.In this paper,a design method of integrated action deduction system including protection logic reasoning and software and hardware operation condition is proposed.The system can receive real-time operation information of protection online,simulate different types of faults,and output the recording information of sub modules belongs to the action deduction system.It can realize the online monitoring of device faults such as deducing the correctness of setting values at a certain time in the future,giving the wrong action warnings and predicting the probability of them as well,which effectively improves the operation and maintenance efficiency of the secondary system in the intelligent substation.

Research on the Protection of World Heritage in China

The world heritage is the resource and wealth shared by the people of the world,and it has very important value.With beautiful scenery and splendid culture,China is a country which has a wealth of heritage resources.By 2016,50world heritage sites in China were named the World Natural and Cultural Heritage by the UNESCO including35world culture heritages,11world natural heritages and 4both cultural and natural heritages.This paper summarizes the general situation of the world heritage sites in China,describes protective measures of Chinese world heritage sites,analyzes the exiting problems and then puts forward proposals to further strengthen the protection of world heritages.

Survival Analysis Using Cox Proportional Hazards Regression for Pile Bridge Piles Under Wet Service Conditions

This paper studies the deterioration of bridge substructures utilizing the Long-Term Bridge Performance(LTBP)Program InfoBridge^(TM)and develops a survival model using Cox proportional hazards regression.The survival anal­ysis is based on the National Bridge Inventory(NBI)dataset.The study calculates the survival rate of reinforced and prestressed concrete piles on bridges under marine conditions over a 29-year span(from 1992 to 2020).The state of Maryland is the primary focus of this study,with data from three neighboring regions,the District of Columbia,Vir­ginia,and Delaware to expand the sample size.The data obtained from the National Bridge Inventory are condensed and filtered to acquire the most relevant information for model development.The Cox proportional hazards regres­sion is applied to the condensed NBI data with six parameters:Age,ADT,ADTT,number of spans,span length,and structural length.Two survival models are generated for the bridge substructures:Reinforced and prestressed concrete piles in Maryland and reinforced and prestressed concrete piles in wet service conditions in the District of Columbia,Maryland,Delaware,and Virginia.Results from the Cox proportional hazards regression are used to construct Markov chains to demonstrate the sequence of the deterioration of bridge substructures.The Markov chains can be used as a tool to assist in the prediction and decision-making for repair,rehabilitation,and replacement of bridge piles.Based on the numerical model,the Pile Assessment Matrix Program(PAM)is developed to facilitate the assessment and main­tenance of current bridge structures.The program integrates the NBI database with the inspection and research reports from various states’department of transportation,to serve as a tool for condition state simulation based on mainte­nance or rehabilitation strategies.

我国设施园艺病虫害发生特点与绿色防控策略

我国设施园艺发展迅速,对促进农业现代化、乡村振兴和都市农业发展具有重要作用。本文结合我国设施园艺产业的发展现状,总结设施环境下病虫害发生特点,并从农业防治、物理防治、生物防治、生态调控、生物技术和科学用药等方面概述了病虫害防治技术,最后对设施园艺病虫害防治提出建议,以期为我国设施园艺的健康可持续发展提供参考。

大型抽水蓄能发电电动机变压器组保护的研发与应用

针对抽水蓄能机组的特点,本文给出了发电电动机变压器组保护的配置方案;介绍了基于采样数据源分区的全工况保护算法,满足抽水蓄能机组保护算法的需求;提出了抽水蓄能机组工况综合判别方法,引入断路器、电气隔离开关以及监控信息的双位置辅助接点,同时设计了一种状态机机制、电气量辅助判别和开关位置报警功能,保证了抽水蓄能机组工况识别的准确性和可靠性;介绍了一种电气量和开入量综合判别的相序保护方案。研制的发电电动机变压器组保护装置已在300MW抽水蓄能机组投入应用,应用效果良好。

基于Prometheus的隧道防护门智能监测系统

隧道是铁路运输过程的重要环节,隧道防护门是隧道中的重要安全防护设备。目前针对隧道防护门的日常检测仍依靠人工巡检,工作效率低。文中根据铁路隧道防护门的特点,研究并构建了一套基于云端、边缘端、采集端一体的监测系统,用于实现对隧道防护门的状态监测与故障告警。系统使用SLS、Prometheus、Grafana等技术对数据进行分析处理,并对相关故障进行检测和告警。本系统的实现验证了云端、边缘端、采集端一体架构在隧道防护门监测中的实用性和可行性。

复杂大电网非预设性运行工况下的继电保护动作适应性仿真分析

非预设性运行工况下的突发事件多,导致继电保护逻辑的适应性较差,不合理区域较多,为此,进行复杂大电网非预设性运行工况下继电保护动作适应性仿真分析。分析历史常规故障,标记故障点最常发生位置,构建零序、负序方向元件模型、距离元件模型、纵联电流差动元件模型,观察复杂大电网非预设性运行工况下的电网参数变化情况,第一时间掌握电网的耦合性,不断选择电网所需的继电保护动作逻辑,确认继电保护动作适应性。仿真实验表明,将故障点设置在保护区域内和区域外,继电保护动作能够根据故障选择不同保护模型进行故障母线切除或者保护不动作,适应性好。

正念认知疗法结合强化自能护理对糖尿病肾病血液透析患者疲乏状况及自护行为的影响

目的:探讨正念认知疗法结合强化自能护理对糖尿病肾病(DN)血液透析患者疲乏状况及自护行为的影响。方法:选取2021年3月—2023年2月厦门市中医院收治的125例DN血液透析患者作为研究对象,随机分为对照组62例和研究组63例,对照组给予常规护理干预,研究组给予正念认知疗法结合强化自能护理干预。对比两组心理状态[焦虑、抑郁自评量表(SAS、SDS)]、疲乏状况[修订版Pieper疲劳量表(PRFS)]、自护行为[糖尿病自护行为量表(SDSCA)]、生活质量[肾脏病生活质量量表(KDQOL-SF)]。结果:护理后研究组SAS、SDS评分较对照组低,差异有统计学意义(P<0.05);护理后研究组PRFS各维度评分较对照组低,差异有统计学意义(P<0.05);护理后研究组SDSCA各维度评分较对照组高,差异有统计学意义(P<0.05);护理后研究组KDQOL-SF评分较对照组高,差异有统计学意义(P<0.05)。结论:正念认知疗法结合强化自能护理能改善DN血液透析患者心理状态,缓解其疲乏,提高患者自我行为、生活质量。

现代稳定型氧化锌压敏陶瓷的直流老化研究进展

现代稳定型氧化锌压敏陶瓷的直流老化功耗随时间持续降低,完全不同于功耗不断上升的传统老化现象,给基础老化理论和工程应用均带来了巨大挑战。这种反常的老化现象已经超出了经典离子迁移老化理论的范畴,其非阿雷尼乌斯特征也使实际状态评估和寿命预测难以开展。文中详述了现代稳定型氧化锌压敏陶瓷的直流老化及恢复特征:正向伏安特性在直流老化后存在“交叉”现象;老化过程可逆,试样充分恢复后能达到其未老化状态。离子重排(donorionredistribution,DIR)老化模型可合理解释氧化锌压敏陶瓷的直流老化现象。氧化锌压敏陶瓷的老化功耗取决于界面态消耗与耗尽层离子“U”型分布之间的竞争,前者导致功耗上升而后者有利于功耗降低。稳定型氧化锌压敏陶瓷的势垒界面态在高温、缺氧气氛等条件下不能保持稳定,其原本下降的功耗也能转变为不断上升。此外,广为应用的功耗(泄漏电流)具有显著的电压依赖特性,并不能反映氧化锌压敏陶瓷真实的老化状态,反向老化系数则有望成为一种有效的老化状态表征参数。通过深化现代稳定型氧化锌压敏陶瓷的老化现象、老化机制及状态评估的认识,本文旨在推进我国高性能氧化锌压敏陶瓷生产制造和高端避雷器发展。

植物乳杆菌发酵三华李果汁工艺优化及贮藏期内品质变化

应用植物乳杆菌对三华李果汁进行发酵。通过益生菌保护剂筛选和发酵工艺优化,建立最优的植物乳杆菌发酵三华李果汁工艺,并在此基础上将三华李发酵果汁在4℃和25℃下进行贮藏实验。结果表明,植物乳杆菌发酵三华李果汁的最适益生菌保护剂为低聚异麦芽糖,最优添加量为0.50%,最优发酵条件为:接种量3%、发酵温度37℃、发酵转速200 r/min,在此条件下三华李发酵果汁中植物乳杆菌活菌数可达108 CFU/mL,显著高于未优化之前。不同温度下贮藏的三华李发酵果汁植物乳杆菌活菌数在10^(7)~10^(8)CFU/mL,符合益生菌发酵果汁要求。贮藏期间,植物乳杆菌均能不同程度地消耗三华李发酵果汁中苹果酸,代谢产生乳酸或乙酸。4℃贮藏28 d后,三华李发酵果汁中可溶性固形物、总酚、总黄酮、总花色苷、ABTS^(+)·清除率和FRAP分别下降了0.20 Brix°、3.71%、1.52%、30.52%、6.22%和0.08 g TE/L,但其可溶性固形物含量、活性物质含量及抗氧化活性均高于25℃贮藏。因此在实际生产中,植物乳杆菌发酵三华李果汁更适合贮藏在4℃。研究结果为植物乳杆菌发酵三华李果汁的工业化生产和应用提供理论基础。

不同气候条件下土壤有机碳水热响应驱动机制研究

土壤有机碳(SOC)是陆地生态系统中最大的碳库,其对气候变化的响应直接影响全球碳循环。然而,关于土壤有机碳对长期水热变化的响应及其微生物调控机制尚不清楚。借助跨气候带土壤移置试验平台,开展了一项8年的土壤移置试验,其中将寒温带地区(中国海伦)的黑土剖面移置到温带和中亚热带地区(即封丘和鹰潭)来模拟土壤水热条件增加。水热增加提高了植被生物量,地上部植株C/N与微生物酶活性;降低了土壤有机碳、全氮、微生物残体碳(MNC)和活性矿物的相对含量。并且,微生物残体碳对有机碳的贡献也随着水热条件的增加而降低。通过计算ΔMNC/ΔSOC以表征水热增加后微生物残体碳损失速率。结果发现,ΔMNC/ΔSOC随着水热条件的增加而显著增加,封丘地区为72.50%±9.35%,而在鹰潭达到了82.67%±2.37%。重要的是,土壤活性矿物的变化与ΔMNC/ΔSOC呈强烈的负相关关系,突出了矿物保护在调控ΔMNC/ΔSOC发挥的关键作用。这些结果表明,水热增加降低了土壤矿物对微生物残体碳的保护和/或刺激了土壤中微生物对微生物残体碳的利用,通过减少微生物残体碳促进了有机碳的显著损失。

水文水质条件对河段纳污能力的影响---以乌东德库尾攀枝花河段为例

定量分析水文水质条件变化下河段纳污能力变化,对于流域或区域水资源保护和水污染防治具有显著现实意义。以金沙江乌东德库尾攀枝花市三堆子—拉鲊河段为研究对象,探究水文水质条件变化对研究河段氨氮纳污能力的影响。结果表明,三堆子断面流量介于900~2000 m^(3)/s、氨氮浓度介于0.10~0.50 mg/L时,研究河段氨氮纳污能力介于235.12~4670.38 t/a,三堆子断面流量和氨氮浓度变化与河段氨氮纳污能力变化基本呈线性相关关系。三堆子断面流量和氨氮浓度较小时,综合纳污能力变化介于0.86~64.23 t/a,水文要素流量占主导作用;流量和氨氮浓度较大时,综合纳污能力变化介于-105.34~-1.84 t/a,水质要素氨氮浓度占主导作用。研究成果可为流域或区域水资源保护和水污染防治提供对策措施和参考依据。

一种条件隐私保护的V2G无证书高效聚合签密方案

针对无证书签名方案不能满足消息机密性,大多数签密方案又存在安全功能不完善、效率低等问题,基于椭圆曲线加密技术提出一种适用于车辆到电网(vehicle-to-grid,V2G)的无证书聚合签密方案。车辆的部分公私钥由自身生成,避免了密钥托管问题。本地聚合器通过聚合解签密,提高了验证效率。通过假名机制提供条件隐私保护,保证合法车辆的匿名性与对恶意车辆的追溯和撤销。采用二元多项式实现车辆假名自主更新。在随机预言机模型下,证明了方案在自适应选择密文攻击下满足不可区分性(IND-CCA2),在自适应选择消息攻击下存在不可伪造性(EUF-CMA)。Scyther形式化分析工具证明了方案的安全性。性能分析表明,与近年签密方案相比,所提方案平均减少了约12.9%的通信开销和84.4%的聚合解签密计算开销,同时具有更高的安全要求。

矿井提升机控制系统的完善及改进

针对现用矿井提升机控制系统在日常运行过程中存在的磁性开关误动作、安全保护触发条件不全及保护动作条件不合理等问题,设计并完善相关控制工艺及程序,使提升机安全保护的监测更加全面,动作更加灵敏、可靠,进而确保提升机的安全、稳定运行。

论发展权视域下残疾人的权利保障

保障残疾人发展权不仅体现了马克思主义人权观,也体现出国家尊重和人权保障。在全面推进依法治国的进程中,当前我国保障残疾人发展权的条件已然具备,在此基础上,针对现有的条件和不足,立足于中国式现代化,进一步提升残疾治理能力和水平。通过激发残疾人内生动力,深入推进农村残疾人社会保障和公共服务等路径进行完善,从而更高质量地保障残疾人发展权。

计及隐私保护的弱中心化多产消者能量共享机制

在双碳目标的背景下,虚拟电厂、微电网等形式的产消者大规模涌现。多产消者之间的能量共享能够提升整体的经济效益与新能源消纳水平。在计及各产消者数据隐私的基础上,文中提出弱中心化模式下的多产消者能量共享协同运行机制。首先,构建含多种分布式资源的产消者内部调度模型,并考虑负荷需求以及新能源出力的波动性与随机性,基于条件风险价值(conditional value at risk,CVaR)量化不确定性带来的风险。然后,提出多产消者弱中心化电价迭代机制,利用供需关系引导电价更新。同时考虑到产消者隐私保护,基于Paillier同态加密算法和秘密共享原理设计电量数据聚合方法。该方法能够在各方主体隐私得到保护的前提下获取系统的供需信息。最后,通过算例验证了文中所提机制的有效性与合理性,且经过能量共享后多产消者整体成本降低12.6%。

变电站继电保护设备状态检修技术分析

简要介绍了变电站继电保护设备状态检修技术,并围绕历史运行情况分析、实时运行情况分析、综合分析、离线检修技术、在线检修技术、断路器状态检测技术、多样化应用场景、状态检修管理系统构建与运行等维度,探讨了相应的技术应用要点。