基于HHT谐波与间谐波检测研究

为了削弱基于经验模态分解EMD（empirical mode decomposition）方法在谐波与间谐波检测中的端点效应,提出了采用自适应波形延拓的改进型希尔伯特-黄变换HHT（Hilbert-Huang transform）谐波与间谐波检测算法。在EMD过程中,采取分段三次Hermite插值函数取代三次样条插值函数,从而避免包络曲线产生的过冲与欠冲。待测信号经过EMD,获得一系列固有模态分量IMFs（intrinsic mode functions）,然后对各个IMF进行希尔伯特变换HT（Hilbert transform）,即可获得各次谐波的幅值与频率。通过与快速傅里叶变换FFT（fast Fourier transform）相比较,证明改进的HHT算法精度高,符合电力系统谐波和间谐波分析的要求。     

一种基于图形处理器加速的批量LU分解算法

潮流计算是电力系统计算的基础,其核心是LU分解计算,因此电力系统潮流计算加速的关键在于LU分解加速。当前,基于中央处理器(CPU)的并行算法已经成熟,性能提升空间有限。图形处理器(GPU)作为协处理器,在科学计算方面具有强大的优越性,被广泛应用到电力系统潮流计算中。文中首先分析了GPU结构和并行运行架构,然后介绍了LU分解原理,并选择了合适的矩阵排序算法和稀疏矩阵存储模型,借助统一计算设备架构(CUDA)编程模型实现了基于GPU的单个LU分解和批量LU分解并行加速,最后在仿真设备上测试了5个不同的案例,对比分析其并行算法的加速效果。仿真测试结果表明,基于GPU的批量稀疏LU分解并行算法,平均可以获得25～50倍的加速效果。     

组合励磁稀土永磁同步发电机的样机设计和试验验证

本文介绍了一种能解决永磁发电机调压问题的新型发电机——组合励磁永磁同步发电机的样机设计和对样机的试验,以验证这种新型发电机的设计思想.     

塑料注塑的CAD／CAE／CAM（Ⅴ）注塑模计算机辅助制造

给出了一个加工复杂注塑模的ＣＡＭ系统，包括从毛坯到合乎设计要求的模具成品的加工过程的多个环节，主要对加工的刀具轨迹的自动生成及干涉检查、曲面检测轨迹的自动生成及干涉检查、精加工的刀具轨迹的自动生成作了详细介绍。     

地质矿产分析测试元数据标准研究

元数据（Metadata）是说明数据内容、质量、条件、查询和其他有关特征的背景数据,在信息共享中有重要作用.本文重点介绍了地质矿产分析测试元数据标准和元数据库管理系统的研究.     

Grant-sizing-differentiated bandwidth allocation algorithm for the coexistence of ONUs with and without wavelength tunability in WDM/TDM PONs

Adopting the pay-as-you-grow approach to upgrade passive optical network (PON) facilities by WDM technology insures the smoothness of the upgrade, and also results in the coexistence of wavelength-fixed/tunable optical network units (ONUs) in WDM/TDM PONs. Dynamic bandwidth allocation (DBA) is the key to support such coexistence of heterogeneous ONUs. Thus, DBA is also the key to support the smooth evolution of PONs. To more fairly coordinate the bandwidth allocation among the coexisting heterogeneous ONUs, a differentiated grant sizing (DGS) scheme is proposed. In DGS, not only the fairness between the wavelength-fixed/tunable ONUs but also the fairness between the lightly/heavily loaded ONUs is taken into account. To further carry out load balancing among wavelengths, a grant scheduling scheme is also proposed to cooperate with the grant sizing scheme. In the grant scheduling scheme, a measure of the ONUs’ flexibility is given, and then the least flexible job first rule (LFJF) is adopted for joint wavelength and time-slot assignment. Finally, to demonstrate the effectiveness of the proposed algorithm, a series of comparative analyses is conducted based on simulation experiments.     

Robust Fabrication of Nonstick,Noncorrosive, Conductive Graphene‐Coated Liquid Metal Droplets for Droplet‐Based,Floating Electrodes

Nontoxic liquid metals (conductive materials in a liquid state at room temperature) are an emerging class of materials for applications ranging from soft electronics and robotics to medical therapy and energy devices. Their sticky and corrosive properties, however, are becoming more of a critical concern for circuits and devices containing other metals as these are easily destroyed or contaminated by the liquid metals. Herein, a feasible method for fabricating highly conductive graphene‐coated liquid metal (GLM) droplets is reported and their application as nonstick, noncorrosive, movable, soft contacts for electrical circuits is demonstrated. The as‐prepared GLM droplets consist of a liquid‐phase soft core of liquid metal and a slippery outer layer of graphene sheets. These structures address the issue of simultaneous control of the wettability and conductivity of a soft electronic contact by combining extraordinary properties, i.e., nonstick, noncorrosive, yet exhibiting high electronic conductivity while in contact with metal substrates, e.g., Au, Cu, Ag, and Ni. As proof‐of‐concept, the as‐prepared GLM droplets are demonstrated as floating electrodes for movable, recyclable electronic soft contacts in electrical circuits.     

Fabrication of dense barium zirconate fibers by electrospinning with different complex agents

Acetic acid, lactic acid, and trifluoroacetic acid were used as complex agents for the preparation of dense barium zirconate fibers with electrospinning method. The formation of lactate when lactic acid was used as complex agent led to a mild decomposition process which was beneficial for the fabrication of dense barium zirconate fibers. High temperature stable intermediate phase of BaF₂ appeared when trifluoroacetic acid was used. The intermediate phase of BaF₂ was disadvantageous for pure and dense barium zirconate formation. While water vapor preheat treatment for BaF₂ contained fibers was an effective way for the fabrication of pure and dense barium zirconate fibers.