Mo-Ti体系合金的液相烧结与组织结构

设计了 Fe- Al烧结助剂进行 Mo- Ti体系合金的低温液相烧结 ,详细探讨合金在烧结过程中的组织结构变化以及 Mo- Ti合金的致密化机理。研究表明 ,Fe- Al添加剂对 Mo和 Ti的致密化均有明显的效果。Mo与 Ti在 Fe- Al添加剂的作用下发生了不完全的固溶反应 ,形成的部分 ( β- Ti,Mo)固溶体有效促进了不同组成配比的 Mo- Ti合金的烧结致密化     

Design of a permanent magnetic circuit with air gap in a magnetic refrigerator

We calculate the magnetic field distribution of a permanent magnetic circuit with an air gap in a magnetic refrigerator by a finite-element method, and compare the field strengths of different structural parameters of the magnetic circuit. We show how the structure of the magnetic circuit can be optimized and present some approaches to improve the structure for a specific magnetic circuit. The main purpose is to provide basic parameters for the design of a practical magnetic refrigerator.     

Effect of synthesis temperature on density and microstructure of MgB2 superconductor at ambient pressure

The experimental thermodynamic of MgB₂ synthesis process and phase compositions have been investigated by diffraction thermal analysis (DTA) technology and X-ray diffraction. The fabrication of MgB₂ bulks and superconducting properties at the temperatures range from 600 to 800°C were reported. And microstructure of MgB₂ bulks were observed by scanning electron microscope (SEM). A method was developed to determine the porosity of MgB₂ and the highest density can be obtained in MgB₂ prepared at 650°C at ambient pressure. It is found that the vapor pressure of Mg increases remarkably at high temperature, leading to the high porosity in MgB₂ samples. MgB₂ bulk with good superconducting property and fine microstructure was synthesized at 750°C.     

一种新型混合电力滤波器及其并联电感设计

介绍了一种由无源滤波器和有源滤波器组成的新型混合电力滤波器.由于在有源滤波器两端并联了一个电感,可使有源滤波器的容量极小.提出了该并联电感的设计原则.实验结果验证了理论分析和设计方法的正确性.     

运用不确定度对日常计量数据进行分析

一般来说在计量学不确定度用于标准装置的评定,而在日常生产过程中极少引用,本文是对不确定度在实际生产中运用的尝试.本文就不确定度评定、分析方法进行了阐述和实际分析,论述了在生产过程中,对使用温控系统达到预期效果:±3℃的效果.     

高压输电线路铁塔选型漫谈

本文结合近几年来,我国高压输电线路铁塔选型方面的基本情况,和作者本人从事高压输电线路铁塔结构设计中的一些经验和看法,简述了大负荷、新结构的塔型使用现状和铁塔选型应注意的一些问题。     

基于最小二乘拟合的不同探针测量线宽的比较

AFM探针的形貌和尺寸对纳米尺度线宽的测量有较大影响．首先建立了一个基于最小二乘的应用于AFM测量技术的线宽计量模型，并使用三种不同探针在NanoScopeⅢa型AFM上对设计线宽尺寸为1000nm的样本进行了测量．应用该模型和算法对线宽进行计算，揭示出探针尺寸对线宽测量结果的影响以及该模型对探针尺寸的依赖性．     

Effect of Exogenous Rare Earths on Microbial Characteristics in Paddy Soil

Duetoincreasingcropyieldsandimprovingcropquality ,REammoniumhydrogencarbonatecomplexfertilizerwereappliedwidelyinsoils ,whichacceler atetheaccumulationofREinsoilsafteragriculturalapplication[1,2 ] .Previousstudieshavereportedaccu mulationofREsinsoilissignificantafter 3monthsofagriculturalapplication[3] ,andREhardlymigratedownward[4 ] .Itiscertaintythatagriculturalapplica tionofREcanresultREaccumulationinsoilandmayhaveaneffectonsoilmicrobialactivities .Soilmicro bialbiomassisamarkerofthemi…     

Triboluminescence of A New Europate Complex

A new europium (Ⅲ)complex Eu(HFNH)3Phen (HFNH: 4, 4, 5, 5, 6, 6, 6-heptafluoro-l-(2-naphthyl)hexane-1,3-dione ; phen : 1, 10-phenanthroline) was synthesized and its tribolumineseent phenomenon was observed. Photoluminescence and tfiboluminescence spectra were successfidly determined. The most intense tfiboluminescent emission originates from the transition of the central Eu^3 ion from ^5D0 level to ^7F2 level. The tribolunlinescent spectrum is basically similar to that of photoluminescence, which correlates with the disorders of F atoms.     

"电子警察"管理信息系统初探

“电子警察”技术的发展和系统的扩展，到今天，各城市每天会采集大量的交通违法数据，原有的系统是难以对这些数据进行处理和管理，需要用新的系统来对这些数据进行管理。本文通过对广州市“电子警察”管理信息系统的现状及其存在问题进行了分析和探讨，并对系统体系架构和实现手段进行了研究，以供大家商榷。