宝玉石颜色的呈色机理

本文从宝玉石的化学结构出发，运用晶体场理论和配住场理论，对宝玉石颜色的产生机理进行了论述和探讨，解释了颜色产生的奥秘．     

论赛博空间中的学习革命

计算机和网络迅速普及为人类创造出一个新型的虚拟生存空间——赛博空间。其独特性质和在教育中的广泛应用引发了一场新的学习革命 ,导致了学习时空、学习基石、学习形态的重大变革。这必将产生新的学习理念 :开放学习 ,个性化学习 ,终身学习 ,虚拟学习 ,学会学习 ,学会创造。新世纪的学习者应积极迎接这场新的学习革命 ,努力培养自己的“电子学习”的能力 :学好计算机和网络的有关知识 ,提高信息实践能力 ,重视英语学习 ,提高信息免疫力。     

有顾客时间窗和发货量变化的车辆调度干扰管理研究

为解决由顾客需求变化引发的物流配送干扰问题,提出基于干扰管理思想构建扰动恢复策略和方案.应用虚拟多车场实现车辆调度扰动恢复问题转化.提出车辆调度扰动恢复策略和扰动度量方法,以作为车辆调度干扰管理建模的基础;分析顾客时间窗和发货量变化造成的扰动并进行辨识.建立相应的干扰管理模型,提出归一化处理办法对VRPTW、MD-VRPTW和MDVRPTW干扰管理问题进行有效兼容;结合干扰管理模型的特点,改进基于顾客的编码表示方法,可以反映出车辆调度扰动恢复策略;根据干扰管理思想,设计遗传算法对干扰管理模型进行求解.给出了一个具有代表性的算例试验结果,算例结果及其分析表明干扰管理模型和遗传算法的有效性.     

基于需求预测的两级动态配送路径优化研究

针对传统响应式配送难以应对海量动态客户需求的困境,在此提出基于需求预测的两级动态配送路径优化方法。利用历史数据从需求预测、需求聚类和需求配额三个维度,处理电商物流配送过程中的动态需求;建立基于需求预测的单阶段和多阶段两级车辆配送路径优化模型,并针对问题特性利用分支定界算法与CW-禁忌搜索算法生成两个阶段的最优配送路径。最后结合实验案例对模型与算法的有效性进行验证,试验结果表明本文设计方法具有较好的动态场景适应度和客户响应能力。     

Topological Performance Measures as Surrogates for Physical Flow Models for Risk and Vulnerability Analysis for Electric Power Systems

Critical infrastructure systems must be both robust and resilient in order to ensure the functioning of society. To improve the performance of such systems, we often use risk and vulnerability analysis to find and address system weaknesses. A critical component of such analyses is the ability to accurately determine the negative consequences of various types of failures in the system. Numerous mathematical and simulation models exist that can be used to this end. However, there are relatively few studies comparing the implications of using different modeling approaches in the context of comprehensive risk analysis of critical infrastructures. In this article, we suggest a classification of these models, which span from simple topologically‐oriented models to advanced physical‐flow‐based models. Here, we focus on electric power systems and present a study aimed at understanding the tradeoffs between simplicity and fidelity in models used in the context of risk analysis. Specifically, the purpose of this article is to compare performance estimates achieved with a spectrum of approaches typically used for risk and vulnerability analysis of electric power systems and evaluate if more simplified topological measures can be combined using statistical methods to be used as a surrogate for physical flow models. The results of our work provide guidance as to appropriate models or combinations of models to use when analyzing large‐scale critical infrastructure systems, where simulation times quickly become insurmountable when using more advanced models, severely limiting the extent of analyses that can be performed.     

低碳环境下的车辆路径问题及禁忌搜索算法研究

基于节能减排的新视角,本文研究了低碳环境下由第三方提供运输服务的车辆路径问题,在安排车辆路径时,同时考虑了能耗、碳排放和租车费用,而这些费用不仅与距离有关,也与客户点的需求量和车辆速度有关。提出了考虑车辆运量和速度的能耗计算方法,建立了非满载运输方式下的低碳路径模型——LCRP。设计了基于路径划分的禁忌搜索算法RS-TS对问题进行求解,该算法引入了一种新颖的路径编码与解码算法WSS,采用了三种邻域搜索方法。通过基准测试实例验证了算法能有效地找到满意解,并揭示了距离、能耗、行驶时间等参数之间的关系,实验分析表明采用低碳路径安排更加经济环保且选择中低的交通速度更有利于节约能耗和降低碳排放。     

ANP-Fuzzy方法在电力企业绩效考核中的应用研究

本文针对我国电力企业绩效考核指标间具有相互影响关系,且大多定性指标难以精确界定的特点,给出了一种ANP-Fuzzy的综合评价法。首先,建立系统的绩效考核指标体系及具体的考核标准,为考核员工提供规范化的评价框架。其次,设计能够准确反映考核指标间相互关系的ANP网络结构,以此确定具有联系性的指标权重。在此基础上,设计能够精确界定定性指标的Fuzzy多层次评价结构,以此评价具有模糊性的员工绩效。最后,运用Super Decisions软件和Matlab软件,给出了基于ANP-Fuzzy方法的电力企业员工绩效考核实证研究。结果表明,该方法合理可行,能够真实反映员工绩效,并且能够有效区分员工自身不同方面的绩效差异以及员工之间的绩效差异。这对帮助员工发现绩效改进空间,不断提升自身绩效具有明显效果。同时,该方法可以借助软件实现,将其应用于电力企业绩效考核具有较强的操作性。     

基于联合配送的开放式动态车辆路径问题及算法研究

针对跨区域多配送中心多车型开放式动态联合配送问题,通过引入时间轴概念将动态问题转化为静态问题,建立考虑车载率的开放式车辆路径模型,提出多配送中心问题的整体算法和多车型的使用原则,强化物流资源整合和跨区域路径整体优化.利用云模型中云滴的随机性与稳定倾向性,改进遗传算法中交叉与变异概率的设置方式,采取“初始优化+实时优化”的两阶段求解策略,对开放式动态车辆路径问题进行实时再优化.最后,结合算例对模型和算法的有效性进行验证.     

An evaluation of the tandem configuration automated guided vehicle system

The performance of a tandem automated guided vehicle (AGV) system is compared with that of conventional AGV track systems. In the tandem system the track is divided into non-overlapping, single-vehicle closed loops. Using simulation it is shown that, because of trips requiring delivery across loops, the tandem system has a higher expected travel time per load and thus a greater average time in system. When the loads are delivered within the original loop only, the tandem system has a lower average time in system than in conventional systems, although the difference is modest. Track layout appears to influence the average time in system much more than docs the dispatching rule invoked. The success of the tandem system is highly dependent on approximately even AGV utilization, which may be difficult to obtain in practice.     

稳恒电流条件下导线上的电荷分布

本文叙述了在稳恒电流条件下导线内部电荷密度分布，并指出了稳恒电流的磁效应对导线内部电荷分布的影响。