A novel multi-channel porous structure facilitating mass transport towards highly efficient alkaline water electrolysis

An advantageous porous architecture of electrodes is pivotal in significantly enhancing alkaline water electrolysis(AWE)efficiency by optimizing the mass transport mechanisms.This effect becomes even more pronounced when aiming to achieve elevated current densities.Herein,we employed a rapid and scalable laser texturing process to craft novel multi-channel porous electrodes.Particularly,the obtained electrodes exhibit the lowest Tafel slope of 79 mV dec^(-1)(HER)and 49 mV dec^(-1)(OER).As anticipated,the alkaline electrolyzer(AEL)cell incorporating multi-channel porous electrodes(NP-LT30)exhibited a remarkable improvement in cell efficiency,with voltage drops(from 2.28 to 1.97 V)exceeding 300 mV under 1 A cm^(-1),compared to conventional perforated Ni plate electrodes.This enhancement mainly stemmed from the employed multi-channel porous structure,facilitating mass transport and bubble dynamics through an innovative convection mode,surpassing the traditional convection mode.Furthermore,the NP-LT30-based AEL cell demonstrated exceptional durability for 300 h under 1.0 A cm^(-2).This study underscores the capability of the novel multi-channel porous electrodes to expedite mass transport in practical AWE applications.

Survivability model of LEO satellite constellation based on GERT with limited backup resources

Survivability is used to evaluate the ability of the satellite to complete the mission after failure,while the duration of maintaining performance is often ignored.An effective backup strategy can restore the constellation performance timely,and maintain good network communication performance in case of satellite failure.From the perspective of network utility,the low Earth orbit(LEO)satellite constellation survivable graphical eva-luation and review technology(GERT)network with backup satel-lites is constructed.A network utility transfer function algorithm based on moment generating function and Mason formula is proposed,the network survivability evaluation models of on-orbit backup strategy and ground backup strategy are established.The survivable GERT model can deduce the expected mainte-nance time of LEO satellite constellation under different fault states and the network utility generated during the state mainte-nance period.The case analysis shows that the proposed surviv-able GERT model can consider the satellite failure rate,backup satellite replacement rate,maneuver control replacement ability and life requirement,and effectively determine the optimal sur-vivable backup strategy for LEO satellite constellation with limi-ted resources according to the expected network utility.

Design of Cold-Junction Compensation and Disconnection Detection Circuits of Various Thermocouples and Implementation of Multi-Channel Interfaces Using Them-A Secondary Publication

Cold-junction compensation(CJC)and disconnection detection circuit design of various thermocouples(TC)and multi-channel TC interface circuits were designed.The CJC and disconnection detection circuit consists of a CJC semiconductor device,an instrumentation amplifier(IA),two resistors,and a diode for disconnection detection.Based on the basic circuit,a multi-channel interface circuit was also implemented.The CJC was implemented using compensation semiconductor and IA,and disconnection detection was detected by using two resistors and a diode so that IA input voltage became-0.42 V.As a result of the experiment using R-type TC,the error of the designed circuit was reduced from 0.14 mV to 3μV after CJC in the temperature range of 0°C to 1400°C.In addition,it was confirmed that the output voltage of IA was saturated from 88 mV to-14.2 V when TC was disconnected from normal.The output voltage of the designed circuit was 0 V to 10 V in the temperature range of 0°C to 1400°C.The results of the 4-channel interface experiment using R-type TC were almost identical to the CJC and disconnection detection results for each channel.The implemented multi-channel interface has a feature that can be applied equally to E,J,K,T,R,and S-type TCs by changing the terminals of CJC semiconductor devices and adjusting the IA gain.

Multi-channel terahertz focused beam generator based on shared-aperture metasurface

Most of existing metasurfaces usually have limited channel behavior,which seriouslyhinders their development and application.In this paper,we propose a multi-channel terahertz focused beam generator based on shared-aperture metasurface,and the generator consists of a top square metal strip,a middle layer of silica and a metal bottom plate.By changing the position and size of the shared-aperture array,the designed metasurface can generate any number of multi-channel focusing beams at different predicted positions.In addition,the energy intensity of focusing beams can be controlled.The full-wave simulation results show that the metasurface achieves four-channel vortex focused beam generation with different topological charges,and five-,six-,eight-channel focused beam generation with different energy intensities at a frequency of 1 THz,which are in good agreement with the theoretically calculated predictions.This work can provide a new idea for designing the terahertz multichannel devices.

Fast pre-stack multi-channel inversion constrained by seismic reflection features

Classical multi-channel technology can significantly reduce the pre-stack seismic inversion uncertainty, especially for complex geology such as high dipping structures. However, due to the consideration of complex structure or reflection features, the existing multi-channel inversion methods have to adopt the highly time-consuming strategy of arranging seismic data trace-by-trace, limiting its wide application in pre-stack inversion. A fast pre-stack multi-channel inversion constrained by seismic reflection features has been proposed to address this issue. The key to our method is to re-characterize the reflection features to directly constrain the pre-stack inversion through a Hadamard product operator without rearranging the seismic data. The seismic reflection features can reflect the distribution of the stratum reflection interface, and we obtained them from the post-stack profile by searching the shortest local Euclidean distance between adjacent seismic traces. Instead of directly constructing a large-size reflection features constraint operator advocated by the conventional methods, through decomposing the reflection features along the vertical and horizontal direction at a particular sampling point, we have constructed a computationally well-behaved constraint operator represented by the vertical and horizontal partial derivatives. Based on the Alternating Direction Method of Multipliers (ADMM) optimization, we have derived a fast algorithm for solving the objective function, including Hadamard product operators. Compared with the conventional reflection features constrained inversion, the proposed method is more efficient and accurate, proved on the Overthrust model and a field data set.

Opportunistic Routing with Multi-Channel Cooperative Neighbour Discovery

Due to the scattered nature of the network,data transmission in a dis-tributed Mobile Ad-hoc Network(MANET)consumes more energy resources(ER)than in a centralized network,resulting in a shorter network lifespan(NL).As a result,we build an Enhanced Opportunistic Routing(EORP)protocol architecture in order to address the issues raised before.This proposed routing protocol goal is to manage the routing cost by employing power,load,and delay to manage the routing energy consumption based on theflooding of control pack-ets from the target node.According to the goal of the proposed protocol techni-que,it is possible to manage the routing cost by applying power,load,and delay.The proposed technique also manage the routing energy consumption based on theflooding of control packets from the destination node in order to reduce the routing cost.Control packet exchange between the target and all the nodes,on the other hand,is capable of having an influence on the overall efficiency of the system.The EORP protocol and the Multi-channel Cooperative Neighbour Discovery(MCCND)protocol have been designed to detect the cooperative adja-cent nodes for each node in the routing route as part of the routing path discovery process,which occurs during control packet transmission.While control packet transmission is taking place during the routing path discovery process,the EORP protocol and the Multi-channel Cooperative Neighbour Discovery(MCCND)protocol have been designed to detect the cooperative adjacent nodes for each node in the routing.Also included is a simulation of these protocols in order to evaluate their performance across a wide range of packet speeds using Constant Bit Rate(CBR).When the packet rate of the CBR is 20 packets per second,the results reveal that the EORP-MCCND is 0.6 s quicker than the state-of-the-art protocols,according to thefindings.Assuming that the CBR packet rate is 20 packets per second,the EORP-MCCND achieves 0.6 s of End 2 End Delay,0.05 s of Routing Overhead Delay,120 s of Network Lifetime,and 20 J of Energy Consumption efficiency,which is much better than that of the state-of-the-art protocols.

风光储参与电网预防-紧急控制策略研究

基于风光储有功功率连续平滑调节能力,提出一种风光储协同切负荷优化的电网预防-紧急控制策略。首先,分析风光储参与电网预防-紧急控制原理,给出风光储参与电网预防-紧急控制策略。在故障发生前通过削减风光出力预留有功备用容量,通过调整发电机机组出力、储能充放电状态平抑风光出力改变引起的系统功率波动;在故障发生后,优先考虑风光预留有功备用量填补系统功率不平衡量,若风光预留有功备用量不足,则采取切负荷措施进行紧急控制。然后,综合考虑风光有功备用成本、预防、紧急控制措施成本,分别建立风光储参与电网预防、紧急控制模型,采用Matlab/CPLEX求解模型。最后在改进IEEE 39节点系统进行仿真验证本文所提控制策略的有效性。

支撑辊边部圆角参数有限元数值模拟

冷轧厂镀锌生产线在生产1600 mm宽规格新镀层产品过程中,带钢边部出现通卷条状色差缺陷,分析认为缺陷原因是四辊光整机支撑辊辊面有效宽度不足所致。利用有限元软件对光整机支撑辊边部圆角参数进行数值模拟,将边部圆角长度由75 mm降至45 mm后,支撑辊辊面有效宽度达到1600 mm,可解决带钢边部通卷条状色差缺陷问题,同时可避免支撑辊辊面过度磨损。

突发疫情下考虑供应中断风险的制造商采购策略研究

突如其来的新冠肺炎疫情给我国人民的生命安全与经济活动带来了巨大的影响,供应链作为经济活动的重要组成部分,不可避免地遭受了冲击,如何应对供应链中断风险是企业面临的重要挑战。论文研究供应链中断风险情况下制造商采购策略,通过引入期权契约,构建不同情形下由低价不可靠的主供应商、高价可靠的后备供应商和风险规避制造商组成的采购模型,并得出以下结论:市场需求和采购价格是影响制造商最优采购量的重要因素,其中当主供应商出现中断时,其可靠性也是影响制造商采购的因素;当市场需求,主供应商的可靠性和成本等影响因素变化时,制造商对主供应商的最优采购决策、对供应链中断应急策略的选择都将发生变化;当且仅当主供应商的供应价格小于制造商向市场销售该产品销售价格和自身制造成本之差时制造商的最优采购量随着期权执行价格增加而增加。

基于SRIO的双备份数据传输

为了解决在特殊条件下数据通道受到外界因素影响导致数据无法传输的问题,提出一种基于SRIO的双备份数据传输设计方案。设计中使用两个独立的SRIO IP核来实现主路通道和备份通道数据的独立传输,同时通过通道选择模块对数据传输通道进行备份选择。该方案以Xilinx的Kintex 7系列FPGA为SRIO的连接设备,物理层以FPGA芯片内部集成的GTX高速串行收发器作为传输基础;传输链路采用“光模块+光缆”代替电缆实现数据的高速可靠传输,该方案已运用到遥测系统数据采集装置项目,实现了FPGA设备间双备份数据传输。

架空线耐张线夹断连对安全备用线夹冲击试验及数值分析

为了探究耐张线夹断连时安全备用线夹承受的冲击载荷及线路关键位置的力学响应,建立了耐张线夹-安全备用线夹-导线耦联瞬断有限元模型。以JL/G1A-630/45-45/7导线为对象,模拟了耐张线夹断连后安全备用线夹单独承受冲击载荷的过程,分析多种档距和高差下耐张线夹断连后安全备用线夹关键位置张力变化。为了验证模型的有效性,开展了多组安全备用线夹受耐张线夹断连冲击试验。研究发现,高差与档距的增加会使安全备用线夹附近节点张力极值和导线振动周期增大。在档距500 m时张力极值和振动周期相较档距为150 m时分别增大了32.08%和140.23%。脱冰跳跃现象的发生会使安全备用线夹附近节点张力极值和导线振动周期减小。增大建立的有限元模型可用于耐张线夹断连冲击数值仿真,在工程当中为避免耐张线夹断连冲击对导线的损伤应减小大档距至500 m以下并降低悬挂点的高度。

考虑5G基站备用储能优化调控的配电网重构双层优化方法

5G基站建设数量激增带来的大量负荷影响了配电网的运行经济性,但基站备用储能在保证可靠性的动态备电前提下能够参与削峰填谷,如何利用配电网重构和储能调控提高双方运行经济性亟待研究。该文首先分析了5G基站备用储能的调控潜力,建立了基站储能可调控容量模型。针对配电网不同拓扑结构的节点可靠性,利用序贯蒙特卡洛法进行评估,提出了考虑节点可靠性的基站储能备电时长确定方法。在此基础上,构造了考虑5G基站备用储能优化调控的配电网重构双层优化模型。通过算例说明,该文提出的重构模型考虑了基站备用储能削峰填谷,使配电网运行经济性更高;重构提高了节点的可靠性,使基站储能拥有更大的调控空间,有效地降低了基站运行成本,实现了双方的互利共赢。

基于退役电池分级互备自适应控制的一次调频

目的“双碳”目标下新能源大量并网导致电力系统等效惯量降低、电能供应不确定性增加,给电网频率安全带来挑战。电池储能响应快速、调节灵活,近年来在电网调频中得到广泛关注。考虑到目前新能源汽车发展迅猛,随之而来的是汽车电池大量退役,计及电池配置成本问题,本文开展如何在安全使用的前提下,充分利用退役电池参与到电网调频应用的研究。方法首先,构建退役电池参与电网一次调频的AGC模型,并分析退役电池充放电深度对其剩余寿命的影响,确定其运行的SOC阈值范围;其次,通过设计出力比例系数,将虚拟惯性和虚拟下垂优势最大化,同时以退役电池SOC为切换条件进行分级自适应控制;然后,引入频率偏差分配系数使另一组退役电池参与备用配合,避免一组电池频繁切换充放电状态损耗电池剩余使用寿命;最后,在MATLAB/Simulink中搭建仿真模型,设置多组参数并对比。结果仿真结果证明,合理利用退役电池能够有效替代新电池参与到电网调频控制中,对电网频率的稳定性及安全运行提供有效支撑。结论本文所提方案中,退役电池能够有效降低电网最大频率偏差,避免电池SOC越限及频率二次跌落。同时,该方案显著减少了退役电池在负荷波动时的充放电切换次数,有利于延长退役电池剩余使用寿命。

含双馈机组风电场备用电缆位置和容量优化方法

链状结构风电场中电缆故障后,故障串部分风电机组将被迫停运。在两串末端增加备用电缆,可以为故障下游风电机组提供输电通道,但对非故障串电缆容量要求较大,利用率低。文章提出一种备用电缆位置和容量优化方法。首先定义最小路矩阵,评估随机风速/电缆故障时风电场输出。根据备用电缆位置对风电场分区。提出有限容量模型解决故障串输电优先性顺序,以确定备用电缆最佳位置。然后引入双馈感应发电机(doubly-fed induction generator,DFIG)稳态约束,采用主从分裂算法,求解风电场潮流。以利用率和成本为目标,提出备用电缆容量的优化模型。最后给出算例分析结果,验证所提方法的有效性。

勒索软件对科技信息安全的影响研究

在国家促进数据安全产业发展的新环境下,科技信息在其数字化转型过程中面临勒索软件的威胁。从科技信息管理者的角度分析勒索软件攻击科技信息的成因,以及造成的区别于以往安全威胁的后果。依据数据安全与网络安全的相关理论和技术,分析被勒索软件Mallox攻击过程中产生的28597条相关日志数据和121539个被加密文件,从而了解Mallox的攻击及加密流程,提出预防勒索软件的方法:自查向互联网开放的服务和网络安全策略,评估服务器被入侵的风险;在日常监测中关注ID 4625的日志数量和安全设备日志,可识别攻击过程;采用异地存储备份、部署EDR服务、使用VPN等方式提高科技信息的安全性。

中国石油地球物理数据共享与数字化转型设想

地球物理数据是油气田公司的核心数据资产,是可持续挖掘的宝贵数据资源。中国石油天然气集团有限公司在几十年的油气勘探开发过程中,获取了海量地球物理数据。大数据时代数据为王,为了更好地保护地球物理数据资产,挖掘数据潜力,提高数据价值,盘活数据资产,中国石油成立了地球物理数据与软件共享中心,对地球物理数据集中统一实施异地备份和资产化共享管理,为海量数据超级计算奠定基础,促进地球物理数据共享使用,解决协同研究工作中的数据孤岛问题,助推地球物理业务实现数字化转型,更好地支撑服务油田公司上游业务发展。

MySQL备份策略

在MySQL数据库的日常维护工作中,经常要做的就是数据库的备份、还原以及导入、导出等操作,也可以说定期对数据库进行备份是保证数据安全的有效措施。基于此,本文主要探讨了MySQL数据库最常见的几种备份方式及策略,并对其优缺点进行了详细分析。

抽水蓄能电站厂用电系统备自投设计及实现

大中型水电站厂用电系统接线复杂,备自投动作逻辑也不简单,同时还需考虑两级备自投之间的动作配合。针对某抽水蓄能电站10 kV及0.4 kV厂用电系统备自投的设计原则、动作逻辑等方面开展了研究,提出两级厂用电系统备自投间的定值及动作时间配合方案,可以保证电站厂用电系统的安全可靠运行。

基于主动防御的电子信息档案灾难恢复系统

针对电子信息档案的可靠性以及安全性的保障问题,提出一种基于主动防御的电子信息档案灾难恢复系统。主动防御机制的构建主要结合拟态马尔科夫博弈理论实现,同时为保证电子信息档案面临灾难能够可靠快速回复,提出基于WLC调度的云灾难备份方案。研究重点针对电子信息档案灾难恢复的主动防御机制进行,以保证电子信息档案的安全可靠,提升数据安全,同时由此进行对比实验,实验结果表明研究系统防御效果更好,文件恢复速度更快。

量子直接通信在商业银行同城数据备份领域的应用研究

量子直接通信是一种利用量子态直接传输信息的通信技术。相较于传统通信技术,其具有更高的安全性,因为它能够发现和阻止窃听。量子直接通信不仅可以实现直接传输机密信息,还可以进行密钥协商、密钥分发等其他任务。基于此,针对商业银行业务实践,本文将量子直接通信技术创新应用于银行同城数据备份领域,为商业银行探索受物理学定律保护的高度信息安全传输新模式,形成量子科技时代银行数据安全新方案。