云广特高压直流输电系统直流滤波器性能的若干问题

介绍实际工程中所用的直流滤波器的形式并讨论其参数的选择方式，同时介绍用于评价直流滤波器设计性能指标的等效干扰电流 Ieq 以及用于计算 Ieq 的三脉动谐波模型。以目前在研待建的云广特高压直流工程为例，利用Siemens公司的谐波分布计算程序HarmDistr进行计算，讨论分析各种因素对 Ieq 的影响。最后针对不同的直流系统运行工况、不同的直流滤波器的投切组合进行直流滤波器性能计算，比较 Ieq 的大小并进行分析讨论。     

转移法色交换

将图Ｇ的着色由一种变为中一种，通常用Ｋｅｍｐｅ法以交换。但是，对于某些情况，用此法无效。针对这个问题，本文提出了一种转移法色交换，它适用于平面图着色，方法直观，清晰且有效。     

岩石样品中铷的中子活化分析

研究了苦味酸溶液的ｐＨ变化对用１８－Ｃ－６（１８Ｃ６）的硝基苯溶液定量萃取Ｒｂ的影响及１８Ｃ６浓度变化对定量萃取Ｒｂ的影响，确定了定量反萃Ｒｂ的实验条件。作出了磷酸锆无机离子交换柱上的Ｒｂ－Ｃｓ分离曲线。测定了岩石样品的微量Ｒｂ和痕量＾８４Ｒｂ。     

心理资本对酒店员工留职意愿的影响 ——以心理授权为中介变量

酒店行业离职率高,提高留职率成为酒店人力资源管理的一大难题.文章对苏锡常地区76家酒店306名员工进行问卷调查,检验心理资本三维度对留职意愿的影响,也检验心理授权在心理资本与酒店员工留职意愿关系中的中介作用.结果表明:心理资本对酒店员工留职意愿有正向影响;心理资本三维度对心理授权三维度有正向影响;心理授权对酒店员工留职意愿有正向影响;心理授权在心理资本与留职意愿的关系中起部分中介作用.因此,从心理资本开发、增强心理授权感知两方面给酒店管理者及员工个人提出建议,以期为酒店提高留职率提供新的管理方向.     

Parametric Stabilization of Quantized Interconnected Systems with Application to Coupled Inverted Pendulums

This paper studies the analysis of parametric stability and decentralized state feedback control of a kind of quantized interconnected systems. The output of each controller is quantized logarithmically before it is input to the subsystem, and the quantized density would affect the stability of the systems. First, a decentralized state feedback controller is designed for interconnected systems without quantization and the corresponding stable region is obtained. Second, for a given controller, the lower bound of the quantization density is evaluated from parameters of local controllers. Finally, the proposed method is applied to coupled inverted pendulums systems which can be viewed as quantized interconnected systems. The simulation results show that by using the proposed quantized controllers, the interconnected inverted pendulum systems are parametrically stabilized.     

Reduced Graphene Oxides Modified Bi2Te3 Nanosheets for Rapid Photo-Thermoelectric Catalytic Therapy of Bacteria-Infected Wounds

Temperature variation-induced thermoelectric catalytic efficiency of thermoelectric material is simultaneously restricted by its electrical conductivity, Seebeck coefficient, and thermal conductivity. Herein, Bi₂Te₃ nanosheets are in situ grown on reduced graphene oxides (rGO) to generate an efficient photo-thermoelectric catalyst (rGO-Bi₂Te₃). This system exhibits phonon scattering effect and extra carrier transport channels induced by the formed heterointerface between rGO and Bi₂Te₃, which improves the power factor value and reduces thermal conductivity, thus enhancing the thermoelectric performance of 2.13 times than single Bi₂Te₃. The photo-thermoelectric catalysis of rGO-Bi₂Te₃ significantly improves the reactive oxygen species yields, resulting from the effective electron–hole separation caused by the unique thermoelectric field and heterointerfaces of rGO-Bi₂Te₃. Correspondingly, the electrospinning membranes containing rGO-Bi₂Te₃ nanosheets exhibit high antibacterial efficiency in vivo (99.35 ± 0.29%), accelerated tissue repair ability, and excellent biosafety. This study provides an insight into heterointerface design in photo-thermoelectric catalysis.     

电力变压器励磁涌流仿真计算的瞬时功率法

本文提出一种基于变压器铁芯材料的基本磁化曲线Ｂ＝ｆ（Ｈ）、变压器铁芯的几何尺寸、空载损耗数值及瞬时功率的概念，对变压器空载合闸时，在各种不同的合闸角及各种不同剩磁的情况下所产生的励磁涌流进行计算的新方法。通过对计算结果的分析，得出励磁涌流的特征，如峰值、波形及间断角的大小同剩磁和合闸角的关系等。本文所提出的方法有助于对电力变压器设计的正确性进行校验及变压器保护的研究。     

Optimization leads to symmetry

The science of complexity studies the behavior and properties of complex systems in mture and human society.Particular interest has been put on their certain simple common properties. Symmetry is one of such properties. Symmetric phenomena can be found in many complex systems. The purpose of this paper is to reveal the internal reason of the symmetry.Using some physical systems and geometric objects,the paper shows that many symmetries are caused by optinfizadon under certain criteria. It has also been revealed that an evolutional process may lead to symmetry.