逆变焊机功率因数的研究

在对大多数逆变焊机的电网输入电路分析的基础上，对电网输入电流和焊机的功率因数进行理论分析和试验研究，提出了改善功率因数的几种方法。     

Influence of TiO_2 on the Alkali Resistance and Structure of Invert Glass

1　IntroductionTheinvertglassisakindofglasswhosenumberofbridgeoxygenyisnotbiggerthan 3.WhenthereisonlyoneglassformerSiO2 ,itsmolarcontentisnomorethan66 .7% .Onthisoccasion ,theglassstructuremaychangefromthree dimensionalconsecutivenetworktolaminarnetwork (y =3) ,chainstructure (y =2 ) ,andislandstructure (y =0 ) [1].TheinfluenceofTiO2 onthealkaliresistanceandstructureintheinvertglasshasnotbeenreported .Thispaperwilldiscussitindetail.2　ExperimentalThematerialsusedwerechemicalpureSiO2 ,TiO…     

Influence of TiO<Subscript>2</Subscript> on the alkali resistance and structure of invert glass

Through measuring the alkali resistance of the invert glass and the quanity of SiO₂ and TiO₂ migrating fron the glass into the solution, the influence of TiO₂ on the alkali resistance of the glass is discussed and its structure is also analyzed by infrared spectroscopy. It is concluded that TiO₂ has double functions for the alkali resistance of the invert glass. On the one hand, both TiO₂ polarizing the secondary ions in glass and TiO₂ isomorphism replacement of SiO₂ make the alkali resitance of the glass decrease. On the ther hand, TiO₂ patching network and anti-erosion covering help to increase the alkali resistance. ZHAO Qing-lin: Born in 1972 Funded by the National Natural Science Foundation of China(No. 59372081)     

谈太原市博物馆干挂铝板—玻璃肋幕墙施工

太原市博物馆为不规则的椭圆倒锥体,致使其外墙幕墙工程施工难度大。本工程采用了敞缝干挂铝板—玻璃肋幕墙方法施工,有效地解决了开缝铝板幕墙施工中的难点问题,取得了良好的经济效益和社会效益。     

高内相逆乳化钻井液体系的室内研究

为了有效降低油基钻井液的油相比例,研制了高内相逆乳化钻井液体系。该体系具有低油、低毒、低固相、较低成本的优异特性。该体系的配方为5#白油+30%CaCl2盐水+HFGEL-120型有机土(w=1%)+石灰(w=0.5%)+脂肪胺类乳化剂(w=3.6%)+自制酰胺类稳定剂(w=1%),油水体积比为50∶50,钻井液的密度为1.20~1.85g/cm3。室内性能评价结果表明:该高内相逆乳化钻井液体系性能良好,破乳电压为400~900V,抗温性达160℃,120~150℃高温高压滤失量≤10mL,流变性与传统逆乳化钻井液相当。进一步评价表明,该体系还具有良好的抗污染性、抑制性、储层保护性能。     

秦岭Ⅰ线隧道仰拱预制块施工技术

介绍了秦岭Ⅰ线隧道仰拱预制块的施工生产,对仰拱块的安装标准、安装方向的控制进行了初步探讨,供类似工程施工参考.     

行星齿轮减速器效率及自锁分析

既传递动力又传递运动的行星轮系,轮系效率是判定能量有效利用程度的重要指标,也是判定是否自锁的条件。由于在行星轮系中存在着效率、传动比和机构尺寸三者间相互制约的矛盾,本文针对2K—H型行星轮系,通过不同功率流向效率曲线的分析,得出了设计行星轮系时正确处理效率、传动比和机构尺寸三者关系的一些措施。     

软开关逆变点焊控制电路的设计

通过对逆变电阻点焊设备的现状分析，介绍了软开关逆变点焊的控制系统．讨论了主控系统、反馈系统的工作原理．并具体设计、实现了单片机对移相芯片UC3879的高精度控制，电流反馈的控制等。     

高电压带电清扫机器人液压调速系统设计

给出了高电压带电清扫机器人（HVCR）液压调速系统设计的详细过程,比较了2种常见的调速系统,介姆了3种变频控制方式,比较了它们的优缺点,并给出了详细的控制策略,对液压调速系统的设计有一定的参考价值。     

Study of Multi-Function Micro-Plasma Spraying Technology

A multi-functional micro-arc plasma spraying system was developed according to aerodynamics and plasma spray theory. The soft switch IGBT （Insulated Gate Bipolar Transistor） invert technique, micro-computer control technique, convergent-divergent nozzle structure and axial powder feeding techniques have been adopted in the design of the micro-arc plasma spraying system. It is not only characterized by a small volume, a light weight, highly accurate control, high deposition efficiency and high reliability, but also has multi-functions in plasma spraying, welding and quenching. The experimental results showed that the system can produce a supersonic flame at a low power, spray Al2O3 particles at an average speed up to 430 m/s, and make nanostructured AT13 coatings with an average bonding strength of 42.7 MPa. Compared to conventional 9M plasma spraying with a higher power, the coatings with almost the same properties as those by conventional plasma spray can be deposited by multi-functional micro-arc plasma spraying with a lower power plasma arc due to an improved power supply design, spray gun structure and powder feeding method. Moreover, this system is suitable for working with thin parts and undertaking on site repairs, and as a result, the application of plasma spraying will be greatly extended.