低氧分压系统及其在二元合金选择性氧化中的应用

根据氧化锆陶瓷管材在高温（＞８７３Ｋ时，因管壁内外的氧分压不同形成氧浓差电池［Ｐｔ，Ｏ２（Ｐ）｜ＺｒＯ２｜空气（Ｐ），Ｐｔ］的原理，研制了可控氧分子（Ｏ２）发射量的低氧分压发生系统。用该系统对Ｎｉ２０Ｃｒ合金进行低氧分压顶氧化处理后，促进了Ｃｒ在１２７３Ｋ时的选择性氧化，提高了合金的抗氧化性能。在低氧分压下，Ｃｕ１．５Ａｌ合金发生了Ａｌ的选择性内氧化。

电力工程母线PT爆炸引起供电系统失压分析

在电力及工业用电系统中,为了监视系统中各相对地的绝缘情况以及计量和保护的需要,在每个变电站、配电房的母线上均装有电磁式电压互感器(PT)。PT的一次线圈并联在高压电路中,其作用是将一次高压电变换成额定电压100V的低电压,用作测量和保护等的二次回路电源,其一次装有熔断器、二次侧装有小型快分断路器对PT本身进行保护。

Ag-In合金在不同氧分压下的氧化现象

利用低氧分压控制系统 ,研究了两种In含量的Ag -In合金在 5 5 0℃和不同氧分压条件下的氧化行为 .结果表明 :在可以发生内氧化的实验条件下 ,合金外表面上都有In2 O3 生成 ,不同氧分压下所生成的In2 O3 表现出明显的形状差异 .0 .2 1× 10 5Pa氧分压下合金试样氧化后表面有颗粒状In2 O3 和纯银块生成 ,而在低氧分压下试样表面只有丝状的In2 O3 生成 .随着合金中In含量的提高或系统内氧分压的降低 ,均可起到促进In2 O3 在试样表面生成的作用 .

特高压气体绝缘组合开关设备中特快速瞬态过电压测量系统的标定

气体绝缘组合开关设备(gas insulated switchgear,GIS)中隔离开关操作会产生特快速瞬态过电压(very fast transient overvoltage,VFTO)。VFTO的全波形包含数十MHz的高频成分和准直流的低频成分。因此,VF-TO测量系统要有良好的瞬态响应和稳态响应特性,这就要求对测量系统的频率响应特性和分压比进行严格的标定。为此,利用阶跃波在均匀传输线中传输的原理,自行设计了阶跃电压行波发生装置,根据电容分压式测量系统输入和输出信号的关系,推导了在输入为理想阶跃信号的情况下,输出信号上升时间和测量系统3dB高频截止频率的关系,标定了测量系统的高频特性。根据测量系统低压臂时间常数和3dB低频截止频率的关系,标定了低频特性,测量系统带宽为0.003Hz～87.5MHz。对安装于实际GIS中的测量系统,使用已知幅值的工频和雷电波标定测量系统的分压比为6.6×105。可见,该测量系统满足对VFTO全过程波形进行测量的要求。

电子式电压互感器谐波准确度试验系统的建立

谐波对电网的计量、品质测量和继电保护均有影响,而电子式互感器由于具有频带宽的优点,为电力系统中的谐波测量提供了解决方式。但国内尚无法进行电子式互感器谐波准确度试验。为此建立了电子式电压互感器谐波准确度试验系统,利用标准电容器组成了分压系统,测量不同频率下电容量,得出分压系统的实际分压比,设定了分压系统的标称分压比。研制出了连接分压系统与校验系统的电压跟随装置,以提高测量准确性,并通过自校准的方法测量了电压跟随器的误差。最终对由分压系统与电压跟随器组成的测量标准系统进行整体的误差分析,将量值溯源到现有标准体系,并对误差结果的不确定度进行了分析。试验数据表明该电子式电压互感器谐波准确度试验系统在2~13次谐波频率下能够满足标准GB/T 20840.8—2007和IEC 60044-8：2002的要求,可对1 000k V及以下电压等级电子式电压互感器的谐波误差进行测量。

IPSEN真空炉电磁阀故障分析与维修

美国IPSEN真空卧式正压气淬炉分压系统工作原理。根据分压系统故障,阐述分压系统的维修和改进过程。

一种基于等离子体的串联补偿电容器间隙技术

针对串联补偿电容器(以下简称"串补")间隙在运行过程中频繁出现误触发的现象,提出一种等离子体串补间隙技术。根据间隙击穿电压分散性大的特点,利用等离子技术大幅度提高间隙距离,避免间隙误触发。为了避免电容分压元件参数变化引起分压系数变化导致间隙误触发的现象,取消了电容分压系统。由于从长电缆耦合进来的干扰会导致间隙控制设备损坏、间隙误触发等问题,利用超级电容、激光供能等措施避免长电缆的使用,降低干扰的影响。通过研究新型的间隙结构,利用重力避免了污秽的产生,从而避免污秽对间隙放电电压的影响。所研制的串补间隙经过三次区内故障、两次区外故障考验均能正确动作。

热电离同位素质谱计负离子检测关键技术的研究

用热电离质谱仪检测负离子 ,因技术上的原因 ,一直是国际质谱界关注的热点问题之一。近几年来 ,在此领域的探索取得突破 ,发展迅速。新型号的质谱上已大量使用这一技术。国内也填补了这一领域的空白 ,并将这一技术成功运用于老质谱仪的升级改造。本文重点阐述了作者本人在探索过程中遇到的疑难问题及解决问题的有效方法。

支撑负离子检测的关键技术

本文重点阐述了本人在探索过程中遇到的疑难问题及解决问题的有效方法:消除电子流对高压系统的影响,负高压的产生和提高荷载能力,磁场反相,离子信号反向和自动控制的改造。

Instantaneous rotation speed measurement and error analysis for variable speed hydraulic system

In order to monitor the working state of piston motor and measure its instantaneous rotation speed accurately, the measuring principle and method of instantaneous rotation speed based on industrial personal computer and data acquisition card are introduced, and the major error source, influence mechanism and processing method of data quantization error are dis- cussed. By means of hybrid programming approach of LabVIEW and MATLAB, the instantaneous rotation speed measurement system for the piston motor in variable speed hydraulic system is designed. The simulation and experimental results show that the designed instantaneous speed measurement system is feasible. Furthermore, the sampling frequency has an important influ- ence on the instantaneous rotation speed measurement of piston motor and higher sampling frequency can lower quantization er- ror and improve measurement accuracy.

一种新型励磁功率电路的研究

提出了一种基于斩波技术的新型励磁功率电路,理论分析表明方案可行,且达到简化装置、提高性能、降低造价的目的,给出了计算机仿真结果。

A New Measurement System for Static and Dynamic Clothing Pressure

This study aims to develop a system and measurement method for investigating the static and dynamic pressure behavior of compression products. The self-designed measurement system, named "cloth-press" (LLY-56B), is a direct measurement method, which is based on a rigid hemisphere with three pressure sensors distributed on its surface. The static pressure is measured at predetermined press depth, and the dynamic pressure is measured under the processing of fabric 3D deformation. The pressure distributions at the basic three sites are accepted as the measurement results. The measurement results provide much information in the field of compression fabric assessment, and the measurement system can be used in scientific research institutes and factories, contributing to optimize process parameters and quality control of compression garment.

Comparison of continuous homogenous azeotropic and pressure-swing distillation for a minimum azeotropic system ethyl acetate/nhexane separation

Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the entrainer and the PSD process with the pressures of 0.1 MPa and 0.6 MPa in two columns are designed and simulated by Aspen Plus. The operating conditions of the two processes are optimized via a sequential modular approach to obtain the minimum total annual cost(TAC). The computational results show that the partially heat integrated pressure-swing distillation(HIPSD) has reduced in the energy cost and TAC by 40.79% and 35.94%, respectively, than the conventional PSD, and has more greatly reduced the energy cost and TAC by 62.61% and 49.26% respectively compared with the CHAD process. The comparison of CHAD process and partially HIPSD process illustrates that the partially HIPSD has more advantages in averting the product pollution, energy saving, and economy.

An extraction method for pressure beat vibration characteristics of hydraulic drive system based on variational mode decomposition

In the pump-controlled motor hydraulic transmission system,when the pressure pulsation frequencies seperately generated by the pump and the motor are close to each other,the hydraulic system will generate a strong pressure beat vibration phenomenon,which will seriously affect the smooth running of the hydraulic system.However,the modulated pressure signal also carries information related to the operating state of the hydraulic system,and a accurate extraction of pressure vibration characteristics is the key to obtain the operating state information of the hydraulic system.In order to extract the pressure beat vibration signal component effectively from the multi-component time-varying aliasing pressure signal and reconstruct the time domain characteristics,an extraction method of the pressure beat vibration characteristics of the hydraulic transmission system based on variational mode decomposition(VMD)is proposed.The experimental results show that the VMD method can accurately extract the pressure beat vibration characteristics from the high-pressure oil pressure signal of the hydraulic system,and the extraction effect is preferable to that of the traditional signal processing methods such as empirical mode decomposition(EMD).

Modeling of D-STATCOM in distribution systems load flow

This paper presents modeling of Distribution STATCOM (D-STATCOM) in load flow calculations for the steady- state voltage compensation. An accurate model for D-STATCOM is derived to use in load flow calculations. The rating of this device as well as the direction of required reactive power injection for voltage compensation in the desired value (1 p.u.) is de- rived and discussed analytically and mathematically by the phasor diagram method. Furthermore, an efficient method for node and line identification used in load flow calculations is presented. The validity of the proposed model is examined by using two standard distribution systems consisting of 33 and 69 nodes, respectively. The best location of D-STATCOM for under voltage problem mitigation approach in the distribution networks is determined. The results validate the proposed model for D- STATCOM in large distribution systems.

Application of a fuzzy analytical hierarchy process to the prediction of vibration during rock sawing

A new predictive model for evaluating the vibration of a sawing machine was developed using a new rock classification system. The predictors are machine parameters and a rock sawability index. The new rock classification system includes four major parameters of the rock： uniaxial compressive strength, abrasiv- ity index, mean MoWs hardness, and Young＇s modulus. The FAHP approach was used when determining the weights of these parameters by six decision makers. Two groups of carbonate rocks were sawn using a fully-instrumented laboratory sawing rig at different feed rates and depths of cut. During the sawing trials system vibration was monitored as a measure of saw performance. Then, a new statistical model was obtained by multiple regression on the machining parameters and the rock sawability index. The model is very useful for the evaluation of the system vibration, and for selecting suitable machining parameters, from a limited set of mechanical properties.

Research on synchronous gear pump

Based on a comprehensive analysis of the structure and existing problems ofthe gear pump, provided a structure principle of a synchronous gear pump.The discussionsfocused on the working principle, construction features and finite element analysis ofthe hydraulic gear.The research indicates that the new pump has such advantages aslower noise, better distributed flow and a high work pressure, and it can be widely used inhydraulic systems.

Stability study on naturally filling body in gob-side entry retaining

In the construction of the filling gob-side entry retaining in a lane, we utilize the self-slide natural phenomenon of a falling gangue in an inclined coal seam goaf. First, we put the falling gangue of goal above the laneway and made it the main filling material by adopting the measurement of flexible supporting system combined with those of rigid supporting system. Then we made the filling material gunited and solidified to maintain the filling goal of the gob-side entry retaining beside the lane. Considering the law of energy conservation and law of pressure distribution for retaining the active and Static soil of the wall, we analyzed the reliability of a gangue blocking facilities and the stability of the filling mate- rial in the lane. We analyze the figures to see the stability. The result shows that the gangue block sup- porting system is reliable, and has been successfully practically applied.

The study on measures to improve the reliability of the hydraulic systems of shearers

The authors indicate that the failure of hydraulic systems of shearers can drop greatly, its’ reliability and service life can be increased by the use of a field oil contamination analyser and filter device to control the oil contamination of the hydraulic systems of shearers. Experimental provement of silting theory contamination analyser are carried out.The filter effect of portable hydraulic driving oil filter model YLJ 21 is examinationed in laboratory and field experiment. From January to August 1992, on site experimental research using a silting theory contamination analyser and oil filter model YLJ 21 to control the oil contamination was carried out in the Datong Coal Mining Bureau.

Quantitative Evaluation on Urban Ecosystem Carrying Capacity in Tianjin Binhai New Area

Based on the concept of ecosystem carrying capacity,the indicator system of quantitative assessment was set up,which consisted of support indicator system and pressure indicator system.And the factor analysis method was used to screen the indicator system.Different from the traditional indicator weight determination based on the absolute values of the coefficients of regression equation,the squares of factor loadings in the rotated component matrix were attempted to determine the weights of 40 assessment indicators.The result shows that ecological support system and pressure system in Binhai New Area are relatively balanced among six years,and the developing level of urban ecosystem is basically healthy on the whole.However,due to continuously increasing pressure of the resources consumption caused by the rapid growth of the second industry,which is the Leading Industry of Binhai New Area,the ecosystem carrying capacity reached the minimum in 2005.