Systems are inherently tied to uncertainty, which necessitates the development of designs and schedules that accommodate this unpredictability. Particularly in modern power systems, the variable efficiency of numerous factors, including pricing, underscores the need for uncertainty modeling. In the meantime, the incorporation of EVs (electric vehicles) into the electrical grid is advancing, with these vehicles being recognized for their role in reducing dependency on fossil energies and enhancing the resilience, stability and efficiency of the grid. However, the rapid growth of the EV sector necessitates thoughtful strategies from decision-makers to manage its expansion effectively, particularly considering the environmental implications associated with the life cycle of EVs, including their charging and discharging processes. This research introduces the conceptual design and optimization approach utilizing a hybrid bat algorithm and differential evolution algorithm (BA-DEA) to improve the efficiency and resilience of EV-smart parking lots under the unpredictable conditions caused by grid pricing fluctuations within the DRP (demand response program). The technique effectively modulates daily costs by adjusting loads among peak and off-peak periods. Key features of the proposed approach include a non-dominated sorting model, innovative variable identification, a memory-based selection process, and the application of fuzzy theory to identify optimal Pareto outcomes. This methodology is not only swift in converging to a solution but also demonstrates a high likelihood of reaching the global optimum. Modeling considerations for smart hydrogen storage systems (SHSSs) incorporate significant constraints, notably those associated with electrolyzers, fuel cells, and storage capacities. The algorithm's effectiveness is validated in scenarios involving parking facilities and multiple uncertain resources, demonstrating a robust reduction in specific cost indicators and adjustments in cost dynamics when DRP is considered. Specifically, the algorithm achieves a substantial 42% decrease in cost variability when DRP is excluded, and a 46.9% reduction in cost variability when DRP is included, despite a minor 5% increase in average cost. These outcomes underscore the proposed system's capability to improve resilience and thermal performance under fluctuating conditions, making it a promising solution for future smart energy systems. Further, the results exhibited the complex interplay between cost optimization and operational adjustments in response to demand-side management.

To improve the properties of AZ31B Mg alloy and for the first time, the rare earth cerium oxide (CeO2) and zirconium dioxide (ZrO2) were combined for synergistic benefits and introduced into the structural AZ31B magnesium alloy through the solid-state friction stir processing procedure to form the hybridized AZ31B Mg/ZrO2+CeO2 composites under variable levels of the tool's rotational speed up to 1200 rpm. The macro-/microstructure, hardness, shear punching strength, tensile strength, corrosion behaviours, and tribological characteristics such as weight/wear loss, wear rate, coefficient of friction, worn surfaces, and debris of the AZ31B Mg/ZrO2+CeO2 hybrid composites were investigated and compared. The results indicated that void, tunnel defect, and ZrO2+CeO2 agglomeration could not be prevented at low speed (800 rpm) while defect-free composites were obtained at high speed (1200 rpm). Grain refinement from 7.39 μm to 3.38 μm and the ZrO2+CeO2 fragmentation (4.52–2.49 μm) ensued after a rise in the tool's rotational speed owing to higher plastic straining, dynamic recrystallization, and ZrO2+CeO2 particle-aided pinning effects. Improvements in hardness (99–135 HV), shear punching strength (121–237 MPa), tensile strength (172–228 MPa) and wear properties of the composite were attained due to the defect elimination, inherent finer Mg grains, and the uniformly dispersed ZrO2+CeO2 particles. These attributes also enhanced the corrosion resistance of the AZ31B Mg/ZrO2+CeO2 composite at the elevated rotating speed of the tool. The combination of the CeO2 and ZrO2 particles is an effective particle-blend for improving the properties of Mg alloy to expand its application scope.

Limited due to the severe shuttle effect, the wide application of lithium-sulfur batteries is difficult to achieve. To overcome this problem, various materials with catalytic effect are developed to inhibit the polysulfide shuttle effect. Herein, we synthesized N-doped porous carbon/Fe2O3 composite (NPC/FO)–efficient catalysts to promote the polysulfide conversion during the electrochemical cycles. Owing to the superior catalytic effect of NPC/FO composite host, the polysulfide shuttle effect could be inhibited. As a result, the as-prepared NPC/FO@S cathode delivered initial high capacity of 1288 mAh/g at 0.1 C. In addition, the NPC/FO@S cathode exhibits excellent rate performance and stable cycling performance. Our finding demonstrates that the N-doped porous carbon/Fe2O3 composites are new efficient host materials for lithium-sulfur batteries.

Owing to the high-energy density and specific capacity, lithium-sulfur batteries are regarded as the most promising energy storage systems, whereas the wide applications of lithium-sulfur batteries are hindered by the severe "shuttle effect" and sluggish redox kinetics of lithium polysulfides. Many strategies have been applied to modify the electrochemical performance, including preparing suitable sulfur hosts, designing functional interlayer, and protecting the lithium anode. Among these strategies, designing functional interlayers is considered as an efficient method to inhibit the shuttle effect and improve the redox kinetics of lithium polysulfides. Herein, MoS2 nanofiber (MSNF) interlayers are prepared and used in the lithium-sulfur batteries. On the one hand, the polysulfide migration could be inhibited due to the chemical adsorption between MoS2 and polysulfide. On the other hand, due to the 3D nanofiber structure of MoS2, it could provide the rapid electron/ion transport and fast redox kinetics. As a result, the lithium-sulfur batteries with MSNF interlayers display high specific capacity and excellent cycling stability.

RV减速器是工业机器人的核心零部件,国产减速器在总体性能上有待提高.对一种新型可替代RV减速器的SG减速器开展测试与分析研究,利用机器人减速器综合测试系统,测试对比SG减速器与RV减速器在空载升速过程中振动、温度、噪声及传动效率等参数的差异,分析SG型减速器的优点与不足,并提出改进方案.研究发现SG减速器在温度、噪声及负载方面更有优势,但在振动及传动效率方面尚待改进.研究结果可为国内新型SG减速器的设计与优化提供参考.

In a multi-stage gear transmission system, the motion state of the system will change with the excitation frequency, and the frequency characteristics will also change accordingly. If this change is not taken into account, there is often a great deviation in identifying and judging system faults according to unified standards, especially when the system has such early undetectable fault as crack. In this paper, the dimensionless differential equations of motion of multistage gear transmission system are established. The stiffness model of gear tooth crack is established by potential energy method. The changes of the motion state of the system with the increase of excitation frequency are obtained by calculating the displacement bifurcation diagram of cracked gear tooth. The influences of crack fault on each motion state are studied by using time domain, frequency domain, phase diagram and Poincaré cross section, and the fault frequency characteristics are summarized. By comparing the theoretical and experimental data of the vibration response characteristics of the system, the motion state of the system can be effectively determined and the crack fault can be identified.

RV减速器是工业机械臂的核心组件,其性能参数对末端精度影响很大.该文以RV-40E减速器为研究对象,利用精密减速器综合测试平台探究RV减速器运行过程中驱动端负载和转速对空载摩擦转矩、空载跑合、定位精度和机械效率等指标的影响,实时监测关键参数的变化,并绘制分析相应测试曲线.研究表明试验台RV减速器四个参数的性能不仅满足国家标准,并且优于同类其他产品.本研究对RV减速器的性能测试与评价具有参考意义.

In the multistage gear transmission system, when multiple faults are coupled, the faults with weak signals are often hidden and hard to identify. Multi-fault coupling may also cause new coupling fault characteristics, such as new peaks or side bands in the spectrum. These characteristics are likely to contain fault information. Studying the sources of frequency components in coupled fault signals will help to decouple the signals and dig out the correlation characteristics between faults. The coupling fault of fixed-axis gear crack and planetary gear tooth broken was studied in this paper. The nonlinear dynamic model of the multi-stage gear transmission system was used for simulation, and the fault frequency characteristics of the system varying with the excitation frequency were obtained. The short-time Fourier transform (STFT) and waterfall plot analysis were applied to the experimental signals to separate the fault features. By comparing the theoretical and experimental signals, we found the natural frequency of the system, the side frequency characteristics of single fault and coupling fault, and the cause of new peaks. This study has a guiding significance for the separation and identification of coupling faults of the multi-stage gear transmission system.

以玻璃形成能力较强的Zr基非晶合金作为研究对象,对Zr41.2Ti13.8Ni12.5Cu10Be22.5非晶合金初始显微结构进行分析,采用热压法对Zr基非晶合金/纯铜的进行了焊接.研究结果表明:通过氩气保护热压法可成功实现Zr基非晶合金/纯铜的焊接,并达到原子级别的冶金结合.当扩散温度为653 K时,在界面附近非晶基体处基本保持非晶态,但是当温度为663 K时,在靠近非晶侧有大量纳米晶形成.因此,扩散温度是影响Zr基非晶合金/纯铜界面微结构的关键因素.

工程力学是近机类工科专业的一门重要专业基础课,也是一门理论与实践紧密结合的课程,结合西京学院新的人才培养目标,从课堂教学、实验教学及课程考核三个方面进行探讨与研究,为工程力学教学改革奠定坚实的基础.

随着塔式起重机广泛应用，焊缝质量检测越显重要。本文综述焊缝常用的无损检测方法，并结合塔式起重机自身结构特点，提出适合塔式起重机焊缝检测的方法，以供同行参考。

本文通过对依托单位现行机械设备管理现状的分析,结合实际的管理流程及用户需求,提出了公路机械设备信息管理系统的设计思想.并利用面向对象的可视化编程工具VB.NET和SQL server2000数据库进行编程,完成了设备信息管理系统的设计.系统对设备进行在线跟踪式管理,将管理人员和操作人员的实际工作纳入管理方案.通过统一的管理方式和规范的管理流程,减轻了管理工作量,同时又提高了工作效率.本系统功能齐全,接口友好,具有较好的实用价值.