摘要：蜂窝结构具有周期性拓扑分布的特征.定制蜂窝结构可在满足特定工程要求的机械性能的同时保持其轻重量的优点.本文旨在探索在冲击荷载作用下,具有不同晶格结构的含缺陷蜂窝夹层板的动态屈曲行为.本文采用均质法来获得不同晶格结构配置的蜂窝芯层的有效材料特性,并采用正弦波、指数、矩形和阻尼脉冲来模拟不同的冲击载荷情况.同时,研究中考虑了两种常见的边界约束类型,即简单支撑和夹持边界.基于冯·卡门非线性理论和一阶剪切变形板理论建立控制方程,然后使用Galerkin方法和四阶Runge-Kutta方法进行求解,并进一步使用Volmir准则来确定结构的临界动态屈曲载荷.本文讨论了晶格结构形状、蜂窝芯相对密度、初始几何缺陷、边界条件、弹性基础系数和结构阻尼对夹层板模型的动态屈曲载荷的影响.此外,文章还给出了研究模型的载荷-重量比,有助于确定最佳晶格单元设计和蜂窝结构相对密度,可服务于工程中特定技术构件的轻量化.

摘要：镁离子电池因其高理论容量和丰富的自然资源被认为是下一代储能系统的潜在候选者.然而,镁离子电池的发展受到镁负极与常见的镁盐和传统有机液体电解液溶剂不相容的限制.因此,电解液的发展是开发高效镁离子电池的决定性因素.镁离子电池的进一步应用所面临的一个主要挑战是开发具有适当的电化学窗口、与镁负极兼容、安全性高的电解液.当前,用于镁离子电池的主要电解液类型包括有机液体电解液、水系电解液、离子液体电解液和固态电解质.本文强调了每个类别中高性能镁离子电池电解液的最新进展,对先进电解液的设计策略进行了系统评估,分析了每种电解液的优点和局限性以及对现有问题的解决方案,并从电解液合成的角度讨论了镁离子电池的发展;最后,讨论并设想了镁离子电池电解液的未来设计,这将对进一步提高镁离子电池的性能提供支持.

摘要：Run-length limited(RLL)codes can facilitate reliable data transmission and provide flicker-free illumination in visible light communication(VLC)*** propose novel high-rate RLL codes,which can improve error performance and mitigate *** RLL coding schemes are developed by designing the finite-state machine to further enhance the coding gain by improving the minimum Hamming distance and using the state-splitting method to realize small state *** our RLL code design,the construction of the codeword set is *** codeword set is designed considering the set-partitioning algorithm *** flicker control and minimum Hamming distance of the various proposed RLL codes are described in detail,and the flicker performances of different codes are compared based on *** are conducted to evaluate the proposed RLL codes in on-off keying modulation VLC *** results demonstrate that the proposed RLL codes achieve superior error performance to the existing RLL codes.

摘要：Software process is a framework for effective and timely delivery of software system. The framework plays a crucial role for software success. However, the development of large-scale software still faces the crisis of high risks, low quality, high costs and long cycle time. This paper proposed a three-phase parallel-pipelining software process model for improving speed and productivity, and reducing software costs and risks without sacrificing software quality. In this model, two strategies were presented. One strategy, based on subsystem-cost priority, was used to prevent software development cost wasting and to reduce software complexity as well; the other strategy, used for balancing subsystem complexity, was designed to reduce the software complexity in the later development stages. Moreover, the proposed function-detailed and workload-simplified subsystem pipelining software process model presents much higher parallelity than the concurrent incremental model. Finally, the component-based product line technology not only ensures software quality and further reduces cycle time, software costs, and software risks but also sufficiently and rationally utilizes previous software product resources and enhances the competition ability of software development organizations.

摘要：在电催化CO_(2)还原(CO_(2)RR)过程中,催化剂的重构经常发生.虽然合理的界面结构与催化位点调控有利于构建优异的电催化剂,但是仍面临诸多挑战.本文通过电化学还原和原位锚定策略合成了单原子铋与铟基底协同的原子桥接结构,从而提高CO_(2)RR的电催化性能.原位结构分析和理论研究表明,多孔碳载体上负载的Bi-In协同位点能够打破原有的结构对称,通过σ键和π*负反馈键形成的电荷密度梯度有利于甲酸盐中间体的吸附,从而实现了高达95.1%的甲酸选择性和持续电解9 d的稳定催化.在太阳能电池驱动下,将5-羟甲基糠醛氧化与CO_(2)RR相耦合,实现了阴极生产甲酸和阳极产生2,5-呋喃二羧酸(88.2%)的高效太阳能-燃料转换选择性.该工作对原子桥连结构活性位点的电催化本质与协同作用机制的理解,为合理设计高性能CO_(2)RR电催化剂提供了重要思路.

摘要：The safety of astronauts would be severely threatened if the lunar-landing spacecraft were under an emergency during the near moon phase of flight, which was far from the Earth. For the problem of mission abort caused by the main engine (service propulsion system, SPS) failure during lunar orbit insertion, firstly, the family of trajectories resulted from SPS premature shutdown and corresponding abort trajectories were analyzed; then an algorithm that can be applied to the near moon abort trajectories was proposed using patched-conic technique. The characteristics of the abort trajectory, such as energy consumption and return time of flight, were analyzed and presented. Finally, simulation examples were given to demonstrate various cases of near moon SPS failure. The results of the simulation have validated the approach proposed.

摘要：Marching-Graph是一种将图形隐喻技术和空间隐喻技术集成为一体的新的可视化方法.它为用户提供了高度可交互性地图,使用户可访问那些具有地理属性的信息的逻辑结构.它通过有效的人图交互和跨空间浏览为用户提供了一种可视分析和挖掘未知信息的机制,而不是将已知的信息呈现在地图上.然而,传统的力导向布局算法在达到力量均衡配置方面非常慢.为使一个图形布局收敛,它们通常需花费几十秒的时间.因此。当用户快速行进于地理区间时,那些力导向布局算法就不能满足快速绘制一系列图形的要求.提出了一种快速收敛布局方法,当用户在Marching-Graph中通过力导向布局逐步探究一系列图形时,它可以加速交互时间.通过结合辐射树绘图技术和力导向图形绘制方法来取得能量最小化的快速收敛.

摘要：The effect of rating scales and test parts of body on the fabric-evoked prickle evaluation results are studied by carrying out subjective evaluation tests under controlled environment conditions (24±1)℃,(65±5) %RH. Ten college female students aged about 20 were chosen as the subjects, who have participated a preliminary training on subjective prickle evaluation. The prickle of a range of 9 light-weight worsted woven wool and wool blend fabrics and a cotton fabric were tested by using a 15 rating scale and using a 010 rating scale respectively at different test parts of body respectively such as forearm, upper arm ball and neck back. The test results were statistically analyzed. It is found that there is a significant correlation coefficient between the evaluation results of using the 15 rating scale and of using the 010 rating scale. It is also found that there are highly significant correlation coefficients between the evaluation results of using the forearm prickle test and the neck back prickle test, between the evaluation results of using the neck back prickle test and the upper arm ball prickle test, and between the evaluation results of using the forearm prickle test and the upper arm ball prickle test. It is suggested that the forearm prickle test is preferable in evaluating fabric-evoked prickle for its convenience and sensitivity.

摘要：流量脉动会引起压力脉动,从而影响液压系统的工作性能,引起结构振动和辐射噪声,会造成液压元件和系统的疲劳破坏,因此仿真分析流量脉动和压力脉动函数对于有效抑制液压柱塞泵的振动和正确设计液压柱塞泵具有重要价值。笔者针对液压泵系统进行定量的振动与噪声分析时所必须具备的激励函数,首先,详细分析了液压泵系统的运行特性,采用傅里叶(Fourier)级数模拟液压泵系统激励函数;然后,建立了压力脉动函数模型;最后,模拟了压力脉动的函数曲线,解决了液压泵系统振动与噪声分析所必需的激励问题。该文为进一步研究液压柱塞泵的定量振动与噪声的响应提供了脉动激励描述,具有理论意义和实际应用价值。