Evaluation method for assessing the auxiliary service transaction mechanism in regional power markets

Accurate and seamless auxiliary services in the power market can guarantee smooth and continuous power system operation. China’s new round of power system reform has entered a critical period, and reform implementation requires comprehensive improvements in the maturity of the supporting auxiliary service market. This study reviews the development status and evolution path of the European unified power market and the US regional power market, provides experience for the development of China’s regional power market, then identifies the key influencing factors of auxiliary service trading mechanism design in regional power markets. To analyze the rationality of the auxiliary service trading evaluation index, this paper established an evaluation model for assessing regional power markets. Using combined weight optimization, the gray correlation TOPSIS method was applied to comprehensively evaluate auxiliary service trading in the regional power market. Finally, the application of the proposed evaluation method was briefly analyzed to examine four regional power markets in China and evaluate the effectiveness of current market construction in different regions and provide suggestions for future market construction.

A portable,auxiliary photovoltaic power system for electric vehicles based on a foldable scissors mechanism

In recent years,countries worldwide have actively advocated electric vehicles for environmental protection.How-ever,restrictions on the driving range and charging have hampered the promotion of electric vehicles.This study proposes a portable,auxiliary photovoltaic power system based on a foldable scissors mechanism for electric vehicles.The system includes a photovoltaic power generation module and an electricity transfer module.The photovoltaic power generation module built based on a foldable scissors mechanism is five times smaller than in its unfolded state,improving its portability in its folded state.The electricity transfer module transfers electricity into the cabin via wireless power transfer units and stores electricity in supercapacitors.Solar simulation exper-iments were conducted to evaluate the system’s performance:maximum output power of 1.736 W is measured when the load is 5Ω,while maximum wireless power transfer efficiency is up to 57.7% with 10Ω load.An elec-tric vehicle in Chengdu city was simulated for a case study.The results show that the annual output of a single photovoltaic power system can drive the MINIEV for 423.625 km,indicating that the proposed system would be able to supply power for electric vehicles as an auxiliary power supply system.

Research and Application for the Regularity of Distribution about Curvature Radius and Curvature Center of the Linkage Point Track in a Link Mechanism

It is illustrated that there exists an inflection circle on the linkage rigid body by the principle of relative motion. Confirmed methods of the inflection circle, curvature radius and curvature center of the point track on the linkage rigid body are given in the case of the different contact type of move instantaneous center line and static instantaneous center line. The regularity of distribution of curvature radius and curvature center of the point track is researched. The identification methods called determination parameters and auxiliary vertical line of the diameter and direction of the inflection circle in the four bar mechanism are pointed out. A design method of the crane hoisting mechanism is discussed in the end of this paper.

Microstructure and Mechanical Properties of Submicron-grained NiAl-Al_2O_3 Composite Prepared by Pulse Current Auxiliary Sintering

Dense and submicron-grained NiAl-Al2O3 composite was fabricated by pulse current auxiliary sintering（PCAS）.Its microstructure was analyzed by XRD,SEM and TEM,and its mechanical behavior was evaluated through compression test and fracture toughness test.The average grain sizes of NiAl and Al2O3 are about 200 nm and 100 nm respectively.The Al2O3 particles dispersed in NiAl matrix,forming intergranular structure and intragranular structure.During sintering,Al2O3 particles were remarkably spherized due to the unique sintering mechanism of PCAS,which is beneficial to the improvement of toughness.The NiAl-Al2O3 composite exhibits high compressive yield strength,whether at room temperature or elevated temperature.Its room-temperature（23 ℃） and elevated-temperature（1 200 ℃） compressive yield strength are up to 2 050 MPa and 140 MPa,respectively.Meanwhile,its fracture toughness is significantly enhanced,which is up to 8.2 MPa？m1/2.It is suggested that the main strengthening-toughening mechanisms are grain refinement strengthening and Al2O3 dispersion strengthening.The fracture of larger NiAl grain is the transgranular cleavage and this is induced by crack tip deflection and grain boundary weakening which are caused by intergranular and intragranular Al2O3 particles,respectively.

基于多尺度细节增强的脑瘤图像分割研究

针对脑瘤图像分割网络的跳跃连接引起的语义特征传递不平衡,以及多尺度特征关联不足,导致细节特征丢失,从而造成对细小目标肿瘤的分割精度不佳的问题,提出一种改进的Res-Unet框架的分割模型。该模型引入多尺度注意力融合模块,通过混合多尺度特征使模型更好地适应不同尺寸的肿瘤;该模型在跳跃连接中引入空间注意力模块,增强特征表达同时避免无用信息的干扰,保留特征图空间细节特征;最后通过辅助分类器模块,在解码器部分对不同尺度特征图进行特征预测。使用BraTS2020数据集进行实验和评估,使用Dice系数来评估模型分割效果。结果显示,改进的网络在全肿瘤区域、肿瘤核心区域和增强肿瘤区域的Dice系数分别为0.8877、0.8229、0.8027,相比于通道注意力模型增强肿瘤区域和肿瘤核心区域的系数分别提升2.6%和0.14%,证明改进模型在脑瘤核磁共振图像分割的有效性和精确性。

低碳复合胶凝材料对水泥和混凝土性能的影响

将粉煤灰和矿粉按不同质量比(m_(粉煤灰)∶m_(矿粉)=7∶3、6∶4、5∶5)制备成了低碳复合辅助性胶凝材料,研究了其等质量替代15%、30%的水泥对胶凝材料需水量比、流动度比和活性指数的影响,优选出了最佳m_(粉煤灰)∶m_(矿粉)。在此基础上,研究了低碳复合辅助性胶凝材料等质量替代0、10%、15%、20%、30%的水泥对胶凝材料标准稠度用水量和凝结时间的影响,以及等质量替代0、10%、20%、30%、40%的水泥对C50混凝土工作性和力学性能的影响。结果表明:在水泥中掺入适量低碳复合辅助性胶凝材料有效改善了胶凝材料体系的工作性,延缓了早期(3 d)水化速度,提高了胶砂7 d、28 d抗压强度,最佳m_(粉煤灰)∶m_(矿粉)为5∶5;随着低碳复合辅助性胶凝材料掺量的增加,胶凝材料的标准稠度用水量变化很小,凝结时间延长;C50混凝土的坍落度随着低碳复合辅助性胶凝材料掺量的增加而增大,7 d和28 d抗压强度先增大后减小,最佳掺量为30%。

基于农田运载平台的烟叶辅助采收机设计与试验

为解决根据成熟度分不同生长时段进行人工采收劳动强度大、采收效率低的问题,设计了一种基于农田运载平台的烟叶辅助采收机。充分考虑烟叶种植农艺规范,将人员乘坐高度调整及烟包提升机构融合设计,满足采摘位置高度调整的要求;设计主从双控电力提升控制电路,保证烟包提升运行效率;开发烟叶采收量定位监测系统,满足田间烟叶采收量分布信息获取的需求。开展了烟包提升系统提升能力性能试验,结果表明:烟叶提升净质量最大为15kg,提升时间最长为13s。烟叶采收量田间试验结果表明:烟叶辅助采收机烟包平均质量为6395g,标准差为1588g;相邻烟包定位点平均距离为5.64m,标准差为4.38m,并获得了烟草田间收获量分布图。烟叶收获效率对比田间试验结果表明:烟叶辅助采收车单人烟叶收获效率平均为30.46g/s,标准差为4.73g/s,与纯人工单人烟叶收获效率相比,烟叶收获平均效率提高78%,采收效率标准差降低1.80g/s,具有较好的采收效率的稳定性。研究结果可为省力、高效、智能烟叶采收机的研发提供技术支撑。

Review on laser directed energy deposited aluminum alloys

Lightweight aluminum(Al)alloys have been widely used in frontier fields like aerospace and automotive industries,which attracts great interest in additive manufacturing(AM)to process high-value Al parts.As a mainstream AM technique,laser-directed energy deposition(LDED)shows good scalability to meet the requirements for large-format component manufacturing and repair.However,LDED Al alloys are highly challenging due to their inherent poor printability(e.g.low laser absorption,high oxidation sensitivity and cracking tendency).To further promote the development of LDED high-performance Al alloys,this review offers a deep understanding of the challenges and strategies to improve printability in LDED Al alloys.The porosity,cracking,distortion,inclusions,element evaporation and resultant inferior mechanical properties(worse than laser powder bed fusion)are the key challenges in LDED Al alloys.Processing parameter optimizations,in-situ alloy design,reinforcing particle addition and field assistance are the efficient approaches to improving the printability and performance of LDED Al alloys.The underlying correlations between processes,alloy innovation,characteristic microstructures,and achievable performances in LDED Al alloys are discussed.The benchmark mechanical properties and primary strengthening mechanism of LDED Al alloys are summarized.This review aims to provide a critical and in-depth evaluation of current progress in LDED Al alloys.Future opportunities and perspectives in LDED high-performance Al alloys are also outlined.

染整工艺对麻纤维抗菌性能的影响

从麻纤维自身形态结构、化学组成出发,分析了影响麻纤维自身抗菌性的因素。概述了染整加工工艺中脱胶、染料种类和染料助剂对麻纤维抗菌性能的影响,总结了麻织物的物理抗菌整理和化学抗菌整理方式。认为:在麻纤维自身具备抗菌性的基础上,采用添加天然抗菌剂、物理抗菌整理、植物染料染色等方法,可有效降低麻纤维生产加工过程中抗菌成分的流失,进一步提高麻织物的抗菌性能。

基于多判别器辅助分类器生成对抗网络的故障诊断方法研究

在强冲击、强辐射、极高温等极端恶劣的工作环境下,机械设备的故障模式复杂多样,获得充足且有效的故障数据变得非常困难甚至难以实现,以致故障诊断的准确性受限,后续检修维护方案难以有效制定。针对这一问题,提出了一种多判别器辅助分类器生成对抗网络的数据增强算法。通过设置3个判别器、1个生成器并添加独立的分类器,构建了新的辅助分类器生成对抗网络模型。针对在该模型训练中存在的不稳定性问题,通过引入Wasserstein距离构造新的损失函数,并采用稳定性更具优势的单边软约束正则化项替换原有的L2梯度惩罚项来解决模型崩溃问题;在此基础上,采用高效通道注意力机制来进一步提高模型的特征提取能力。将所提出的模型应用于扩充机械设备故障数据集,辅助深度学习智能诊断模型的训练。多个故障数据集扩充实验表明,与现有模型相比,新模型所生成数据的质量更高,故障诊断的准确率也得到进一步提高,因此具有较高的应用价值。

基于对抗性双通道编码器的网络入侵检测算法

针对网络流量数据不平衡引起少数类攻击检测率低的问题,提出一种基于对抗性双通道编码器的入侵检测算法。分别采用正常流量和攻击流量来训练变分自编码器模型,构建基于自编码器派生流量数据的多通道表示形式的新特征向量,驱动生成对抗网络的生成过程朝向目标类,生成的少数类图像,有效地扩充数据集;通过引入CBAM模块来改进生成器的网络结构,融合通道和空间两个方向的特征,增强模型的特征提取能力;将判别器输出调整为单目标分类并加入softmax层,输出Fake、Normal和Attack结果,避免生成器生成无法与所需类型匹配的图像而获得奖励,提高生成图片的质量。实验结果表明,该方法能够有效降低误报率以及提高未知攻击的检测精度,尤其在不平衡数据集中具有更多的优势。

Performance-control-orientated hybrid metal additive manufacturing technologies:state of the art,challenges,and future trends

Metal additive manufacturing(AM)technologies have made significant progress in the basic theoretical field since their invention in the 1970s.However,performance instability during continuous processing,such as thermal history,residual stress accumulation,and columnar grain epitaxial growth,consistently hinders their broad application in standardized industrial production.To overcome these challenges,performance-control-oriented hybrid AM(HAM)technologies have been introduced.These technologies,by leveraging external auxiliary processes,aim to regulate microstructural evolution and mechanical properties during metal AM.This paper provides a systematic and detailed review of performance-control-oriented HAM technology,which is categorized into two main groups:energy field-assisted AM(EFed AM,e.g.ultrasonic,electromagnetic,and heat)technologies and interlayer plastic deformation-assisted AM(IPDed AM,e.g.laser shock peening,rolling,ultrasonic peening,and friction stir process)technologies.This review covers the influence of external energy fields on the melting,flow,and solidification behavior of materials,and the regulatory effects of interlayer plastic deformation on grain refinement,nucleation,and recrystallization.Furthermore,the role of performance-control-oriented HAM technologies in managing residual stress conversion,metallurgical defect closure,mechanical property improvement,and anisotropy regulation is thoroughly reviewed and discussed.The review concludes with an analysis of future development trends in EFed AM and IPDed AM technologies.

星罩组合体水平运输辅助支撑机构设计方案

针对星罩组合体水平运输条件下星箭分离装置的疲劳破坏问题,提出增加卫星辅助支撑机构的设计方案。建立辅助支撑机构力学模型,利用解析法计算得到辅助支撑机构设计的重要输入指标;并通过有限元仿真验证辅助支撑机构的性能是否满足使用要求。该辅助支撑机构的设计贯彻了从设计输入、建模、计算到验证的全流程研究方法,可为后续星罩组合体水平运输提供参考。

电力需求响应实施现状综述及展望

中国电力需求响应实施受政策及市场化程度影响,缺乏成熟的激励机制,导致激励不足影响了响应积极性,需求响应项目建设面临诸多挑战。因此,建立和完善需求响应激励机制,并深入挖掘更多的柔性可调节资源,是保证新型电力系统平衡的重要手段。首先,在基于电力需求响应激励方式、实施必要性及可行性等基本概念的基础上,从需求响应潜力评估方法、激励方式、市场主体实施策略以及响应效果评价角度对国内外电力需求响应理论研究成果进行调查分析。其次,基于对国外电力需求响应项目的建设现状的分析,总结了国内电力需求响应政策导向、实施现状及实践经验。最后,在综合考虑电力需求响应实施的理论成果和实践经验的基础上,针对未来中国电力需求响应提出相关建议。

综合能源系统低碳规划与运行研究述评

为提高综合能源系统(integrated energy system, IES)低碳规划及优化运行的技术水平,推进能源结构低碳转型及新型电力系统建设,梳理和总结研究学者在IES的模型构建、系统规划、运行调度等方面的研究成果,该文开展了相关领域的综述研究。首先,阐述了综合能源系统的典型架构、典型设备及其能流特性。其次,针对IES低碳规划和运行策略及其相关支撑技术,分别论述了多态不确定性模型及功率预测、柔性负荷调控策略、IES参与电力辅助服务及其低碳运营机制、优化模型及其求解算法等方面的技术路线及研究成果;研究表明,规划与运行策略是支撑IES低碳、高效、经济运行水平的关键技术,计及不确定性的高维、非线性、多目标、非凸问题的精确建模和快速求解等难点问题亟待深入研究。最后,展望了人工智能、大数据、电力物联网等新技术在IES低碳规划和运行方面的应用前景,归纳了该领域亟待应对的技术挑战和关键问题。

基于改进DDRNet网络的遥感影像山体滑坡识别

山体滑坡是一种极具毁灭性的自然灾害,滑坡灾害识别和调查是预防灾害工作的重要基础。传统山体滑坡识别方法、识别精度和自动化程度均较低,为此,本文提出一种基于深度学习分割网络的山体滑坡识别算法。首先,使用双分辨率网络模型作为主干网络,然后在主干网络中添加卷积注意力机制模块,以增加模型对滑坡特征提取能力,最后在训练阶段添加辅助损失函数,以增加模型对滑坡特征拟合能力。实验表明:与常用的分割模型相比,准确率、召回率、F1得分和平均交并比均有5%左右提升,参数量下降2/3左右;表示所提模型具有较好的滑坡检测能力,可高效精确定位滑坡位置。

辅助站立坐便器设计与试验

针对老龄人及行动不便患者在如厕时存在难以自行站立的问题,设计了一款辅助站立坐便器。首先在对人体自然站立阶段分析的基础上采集了关节运动轨迹数据,提出了辅助站立装置要尽可能地还原自然站立状态需要满足三个原则;其次对菱形传动机构进行分析计算,并对关节理论轨运动迹进行了评估;再次设计了辅助站立机构的功能尺寸,并对其运动稳定性进行了评价;最后通过搭建的原型装置完成了辅助站立实验,结果表明髋关节与肩关节位移幅值分别为22cm和46cm,与自然站立采集结果基本吻合。辅助装置可以还原自然站立状态。

具有机械角度辨识功能的带辅助齿SPMSM设计与研究

永磁同步电机因其高功率密度、高效率以及高可靠性,被广泛应用在各个领域。在对机械角度有要求的应用场合一般使用位置传感器来获取电机转子的机械位置信息,这样会降低控制系统的可靠性、集成度以及功率密度。为了在不借助位置传感器的情况下实现对永磁电机的机械角度辨识,设计了一台表贴式永磁同步电机(SPMSM)的电磁。通过在转子上添加不同高度的辅助齿,使得电机拓扑的电感包含转子机械角度信息。使用有限元仿真软件分析了添加辅助齿对电机反电动势、输出转矩以及三相电感的负面影响。最后在0.75 kW的SPMSM平台上验证了所提拓扑结构的机械角度辨识能力。

基于综合能源储能渗透率的碳排放调频辅助研究

“十四五”规划中强调未来我国的能源结构将发生变化,为降低碳排放量,风电、光伏等新能源装机容量将迎来大幅增长,系统的调频需求将进一步增加。调频辅助服务市场的定价及出清机制对电网调度和安全运行有着重大影响,合理的调频市场设计及定价机制有利于促进调频资源的优化配置,减少碳排放。考虑到储能资源具有良好的调频性能,文中主要探讨了联合出清模式下不同储能渗透率调频辅助服务机制。提出了含储能渗透率因子的调频市场的价格机制;以现有调频辅助服务市场为参考,提出基于层次分析法(APH)的调频性能指标计算方法。文章给出主能量市场与调频辅助服务市场的联合出清模型进行算例仿真,并与传统出清模型进行对比分析,验证了所提方法的有效性。

基于注意力残差网络的急性淋巴细胞白血病分类

当前在处理急性淋巴细胞白血病(acute lymphoblastic leukemia,ALL)分类时存在着背景信息杂乱和的差异性细微问题.由于在血液样本图像中,选取关键特征并减少背景噪声仍然困难,传统方法难以捕捉到重要且细微的特征,难以有效地分类和识别各种血液细胞类型,进而影响了结果的准确性与可靠性.本文提出一种基于ResNeXt50分类模型,采用图像增强来减少背景噪声对图像的影响,并通过改进空洞金字塔特征提取方法增强对各个尺度和上下文信息的感知能力,加入改进SA注意力机制,使得模型可以更好地关注并学习对结果影响较大的信息.本文提出的模型在伊朗德黑兰(Taleqani)医院的Blood Cells Cancer公开数据集进行了实验,准确率和精确率分别达到了98.39%,98.33%,结果表明该模型不仅具备一定的临床意义和实用价值,而且为ALL辅助诊断提供了新的思路.