EDDS应用于Cu/Zn污染土壤电动处理的基础研究

重金属污染土壤的修复是当前的热点研究课题。通过研究可降解有机络合剂EDDS对铜矿区Cu/Zn污染土壤中Cu和Zn最适的浸提时间和浸提液的pH范围,并在此基础上初步研究了将EDDS应用于该污染土壤的电动处理过程。结果表明,24h浸提时间和pH5～8的EDDS浸提液可对污染土壤Cu和Zn的浸提率分别达到25%和10%以上;电动处理过程中用EDDS预先饱和土壤有利于Cu和Zn的溶解,但由于电渗流方向与EDDS及其络合物的迁移方向相反从而不利于EDDS络合物从土柱中的移出;同时较低用量的EDDS对土壤Cu和Zn的电动去除效果不明显。可见,诸多因素影响着EDDS在Cu/Zn污染土壤电动修复中的应用。

铜尾矿砂电动增强处理过程研究

采用电动处理装置,研究了施加不同电压和添加不同浓度EDTA对铜尾矿砂电动处理过程的影响。结果表明,在阴极池溶液pH为3.5的H2SO4且不施加电压的情况下,Cu的去除率仅为3.2%,而当电压升至30V时,去除率增加到43.8%;在采用阴极酸度控制的H2SO4+EDTA处理中,随添加EDTA浓度(0、0.5、1.0、2.0mmol·L-1)的增加,电动处理后尾矿砂中Cu的去除率分别可达19.6%、18.3%、31.5%和37.2%。加入EDTA和升高施加电压均可增强尾矿砂中Cu的活性,提高尾矿砂中Cu的去除率。EDTA的存在降低了电动处理电流,但增加了电渗流量,而提高施加电压则显著增加处理电流。随EDTA浓度的增加尾矿砂的pH也增加,同时其电导率下降。

用电动液压处理降低油井含水

根据文献НефтяноиХоэяйство,1990年第11期,第54～56页知原苏联罗马什金油田的油层具有多层和非均质性的地质构造特点。已对该油田的含水油井进行了各种近井地带处理,极大地提高了油井产能。对该油田含水油井近井地带处理方法之一是油水井的电动液压处理(ЭГВ)。该工艺是用测井电缆将直径为0.114m、可在60℃温度和30MPa压力下工作的电动液压冲击装置下入油井,正对着处理层进行高压放电。由于高压放电产生的脉冲压力在井液中是定向传播的,因此,它可间接地对地层或夹层中的流体进行选择性处理。另外。

浅谈电动机常见故障及处理方法

文章结合工作中生产运行与检修实践,对生产过程中矿用隔爆型三相异步电动机常见的一些问题及解决方案做一简要分析和介绍,供同行参考。

预处理污泥对Cr在玉米和土壤中迁移转移影响

为探究污泥肥料化安全农用的有效途径,有效分离污泥中包埋的重金属,文章设置了T1(污泥肥)、T2(臭氧化污泥)、T3(臭氧化+电动力处理污泥)、T4(普通有机肥)和不添加肥料的5个盆栽实验处理,通过对比不同处理对污泥中重金属Cr的赋存形态影响,研究污泥中Cr在玉米植株和根系土壤中的富集和迁移转化。结果表明,在玉米植株中,同处理不同器官中Cr含量均存在根系>茎秆>叶片>穗轴>籽粒的快速递减规律,而且不同器官之间还存在极显著差异,其中含量最高的T1根系为21.66 mg/kg,籽粒中CK处理的含量最低,为0.48 mg/kg,污泥处理中T3最低为0.65 mg/kg;通过Cr在植株中的分布来看,T1~T4中,T3处理下植株各器官中Cr含量均为最低,T2次之,说明臭氧及电动力处理有助于削弱Cr向植株地上部分的转移;T3处理在不同土层籽粒中Cr的富集均为最低,因此预处理能够有效削弱重金属Cr向植株中的富集以及向籽粒的转移。在土壤中,CK中的Cr含量最低,累积量为63.18 mg/kg,T4中的Cr含量最高,累积量为256.12 mg/kg,污泥处理组中Cr含量介于CK与T4之间,且有上层T3>T1>T2、中层T3>T2>T1、下层T3>T1≈T2的变化趋势;不同土层不同器官对Cr的富集存在较大差异,共同特征是籽粒和穗轴中T1处理富集水平最高,T3处理富集水平最低;各处理对Cr向地上部分转移能力整体比较,T1>CK>T4>T2>T3,电动力处理有助于削弱Cr向植株地上部分的转移。污泥的臭氧-电动联合处理可以有效削弱重金属Cr向玉米中的富集以及向籽粒的转移,保证污泥农用过程中Cr的安全性。

电动法消除船体焊接结构凸起类局部变形

凸起变形是船体焊接结构中常见的缺陷,相对于传统变形校正法,电动加工处理法有诸多优势。为了研究电动法对凸起类变形的影响,通过点状处理法、环形处理法和螺旋处理法等三种电动法处理АМг6铝合金和Ст3低碳钢试样。结果表明,点状处理法能耗最小,环形处理法和螺旋处理法的效率近似,但后者能耗更低,且螺旋法降低凸起变形的效果最好。通过对比分析,电动法的能耗远低于传统方法,符合耗能最小标准。采用铜衬垫的电动处理可消除其对加工金属结构表面的影响。

含油污泥处理技术进展

含油污泥主要来源于原油的开采、储存、运输以及加工等过程。对含油污泥组成、性质以及处理方法和现状进行介绍,分析相应的机理。含油污泥处理方法主要有热解、溶剂萃取、热水洗涤、超声处理、生物处理以及电动力学处理等,通过对含油污泥处理方法进行对比分析,总结了不同处理方法的应用范围及特点。根据含油污泥性质及环保要求,对含油污泥处理技术的发展提出了建议。在含油污泥实际处理过程中应结合含油污泥的性质、处理方法的特点以及处理需求等,借鉴优秀的技术采用复合手段处理,从而达到含油污泥处理资源化的目的。

重金属污染淤泥一维大变形电渗固结–离子迁移耦合模型

电动处理技术在淤泥高效脱水和重金属污染物同步去除方面潜力巨大。基于分段线性差分法,将电渗固结和溶质迁移理论相结合,建立了一维大变形电渗固结-重金属离子迁移耦合模型ECT1。该模型可以模拟电场、渗流场和化学场的耦合作用,可以考虑电动处理过程中土性参数的非线性变化,以及吸附/解吸、中和/电离、沉淀/溶解等多种化学反应。分别采用Alshawabkeh污染土电动修复试验及数值模拟、高含水率重金属污染土电动处理试验,验证分析了ECT1模型的可靠性。通过算例分析,进一步阐述了高含水率污染淤泥电动处理过程中重金属迁移与电渗固结的耦合机理。

氨络合法电化学捕集去除城市污泥中重金属的研究

采用自行设计的电动污泥处理装置,以城市污水厂污泥作为试验对象,设置氨水添加比分别为0、0.08、0.10、0.12(V:V,氨水/试样污泥),在恒定直流电压下运行120h,研究氨络合效应与直接利用阳极产酸对污泥中重金属捕集去除效果的影响.结果表明,阳极酸化对污泥中重金属有一定的溶出去除作用;氨水的添加对电动处理过程中污泥p H值的降低与电流密度的提高没有阻碍,但能够有效提高污泥中重金属的捕集去除率;当氨水添加比为0.12时,污泥中Zn和Cu的捕集去除效果最佳,分别达91.62%和71.49%.氨水添加比为0.08时,Pb的捕集去除率最佳,达47.85%.氨水的添加对污泥中重金属的形态和迁移性有明显影响,主要表现为稳定形态如残渣态、有机结合态的减少及可交换形态的增加.

Effect of electropulsing on dislocation mobility of titanium sheet

To investigate the effect of the electropulsing on dislocation mobility,specimens cut from the cold-rolled titanium sheet were treated by high density electropulsing with the maximum current density of 7.22,7.64,7.96 kA/mm 2 ,pulse period 110μs.The internal friction and elastic modulus were measured by a dynamic mechanical analyzer（DMA）.When strain amplitude lowers a certain critical one,the damping of the electropulsed titanium sheet is lower than that of the cold-rolled one.When the strain amplitude exceeds the critical one,the damping of the electropulsed titanium sheet is extraordinarily higher than that of the cold-rolled or conventional annealed one.Furthermore,it is found that the damping peak of the electropulsed titanium sheet shifts to lower temperature compared with the conventional annealed one.It is demonstrated that the electropulsing treatment can decrease dislocation tangles and enhance dislocation mobility.

MICROPROCESSOR BASED MODEL FOLLOWING ADAPTIVE CONTROL SYSTEM FOR CSIM DRIVES

A model following adaptive control system for CSIM is presented in this paper. A dynamic mathematical model of slip control based system is obtained. With the help of model reducing technique, full order model is reduced to simplify the design without degrading much of the performance. Model following adaptive control laws in discrete form are derived. These laws satisfy the hyperstability condition for taking care of the load and machine parameter changes of the drive. A microprocessor 8098 is used to develop the speed controller. The implementation of the control system uses only available variables of the reference model and the controlled plant. Experimental results are given to demonstrate the good performance of the system.

Design and Development of the DTC Induction Motor Drive for Electric Vehicle

The design and development of the traction controller for electric vehicle is introduced, which is based on the induction motor. This drive is developed by using a digital signal processor at low cost and carried out with the module design concept of both software and hardware. Nevertheless, a scheme of the sensorless direct torque control is based on the developed hardware, of which the feasibility is tested by a trial program. Additionally, both the interface function of the drive hardware and the feasibility of its software are proved to be good by the trail programs. A test motor can run about 18?r/min by a variable frequency program with the space vector pulse width modulation technology, of which the torque is visible pulsatile. In this presentation, based on the theoretical approach, the sensorless torque control is to be studied and applied to electric vehicles, of which the quick, smooth and stable torque response is emphasized because it quite benefits improving the drive performance of electric vehicles.

The Characteristics of Cloud-to-Ground Lightning Activity with Severe Thunderstorm Wind in South and North China

The characteristics of cloud-to-ground(CG) lightning activity with severe thunderstorm wind(STW) in South and North China are analyzed using CG lightning data, radar data, and serious weather reports. The percentage of positive CG(PCG) flashes with STW in North China is larger than that in South China. STW takes place during the period when the total CG and PCG density is increasing fastest. STW also occurs close to the high-value center of CG and PCG density. In North China, the CG and PCG density in the grid of STW maximizes approximately 20 minutes after the STW occurs; while in South China, the PCG density and percentage of PCG in the grid of STW maximizes about 10 minutes before the occurrence of STW. The high-value centers of CG density and PCG density in North China move slightly faster than those in South China, which is opposite to the rate of increasing CG activity.

Effect of T6I6 treatment on dynamic mechanical behaviour of Al-Si-Mg-Cu cast alloy and impact resistance of its cast motor shell

The effect of T6I6 treatment on the dynamic mechanical and microstructure behaviour of Al-Si-Mg-Cu cast alloy was investigated using split Hopkinson pressure bar(SHPB), transmission electron microscopy(TEM), and highresolution transmission electron microscopy(HRTEM). Besides, the impact resistances of T6I6 and T6 motor shells of new energy vehicles made of Al-Si-Mg-Cu cast alloy were compared using a trolley crash test. The results indicated that the main strengthening-phases of the T6 peak-aged and T6I6 peak-aged alloy were GP zone and β″ precipitates. T6I6treatment can increase the density and size of β″ precipitates in peak-aged alloy and enhance both its tensile strength(σb)and elongation(δ). The dynamic toughness values of T6I6 samples are 50.34 MJ/m^(3) at 2000 s^(-1) and 177.34 MJ/m^(3) at 5000 s^(-1) which are 20% and 12% higher than those of T6 samples, respectively. Compared with a T6 shell, the overall deformation of T6I6 shell is more uniform during the crash test. At an impact momentum of 3.5×10;kg·m/s, the T6I6shell breaks down at 0.38 s which is 0.10 s later than the T6 shell.

Position Sensorless Control for Permanent Magnet Synchronous Motor Using Sliding Mode Observer

An approach of position sensorless control for permanent magnet synchronous motor （ PMSM ） is put forward based on a sliding mode observer. The mathematical model of PMSM in a stationary αβ reference frame is adopted, and the system is controlled by the digital signal processor （ DSP; TMS320LF2407 according to the control achieve closed loop operation of the motor, the stator theory of sliding mode observer. In order to magnetic field should be vertical with the rotor magnetic field and be synchronous with rotor rotating, so the position and speed of PMSM is estimated in real time and the estimated position is modified continuously. The simulation results indicate that the proposed observer has high precision is more robust to the parametric variation and load in estimation of PMSM position and speed, and torque disturbance.

Degradation of Wastewater Containing Nitrobenzene by High Gravity-Ultrasonic/Ozonation/Electrolysis Technology

The integrated high gravity-ultrasonic/ozonation/electrolysis technology was applied in the pretreatment of wastewater containing nitrobenzene. The effect ofpH value, high gravity factor, liquid flow-rate and electric current density on removal of COD and nitrobenzene compounds was investigated. Experimental results have determined the optimal pro- cess regime involving a high gravity factor of 100, an electric current density of 20 mA/cm2, a liquid flow-rate of 100 L/h, and an initial liquid pH value of 11. After the wastewater had been treated for 180 rain, the degradation of nitrobenzene and COD reached 99% and 80%, respectively, with the biochemical coefficient （BOD/COD） equating to 0.64, and the subse- quent treatment of wastewater could be carried out by conventional biochemical means. Compared with traditional aeration- ozone contactors, a rotating packed bed with high mass transfer characteristics could be used to increase the ozonation treat- ment efficiency.

Intergranular Corrosion of UNS S31803 Heat Treated at 800 ℃ Varying Range Times

The aim of this work is evaluate the intergranular corrosion on UNS S31803 steel, with heat treatments at 800 ℃, varying treatment times of 30 mins, 360 mins and 1,440 mins. The results confirm the formation of o phases and secondary austenite （γ2）. For the analysis of the influence of o and γ2 phases, metallographic analysis were conducted through optical microscopy, potentiokinetic reactivation electrochemical techniques and potentiodynamic polarization in NaCI 3.5% solution. Microstructural analysis has shown a formation of γ2 and o phase in heat treatment, due to diffusion of chromium and molybdenum from δ phase to y phase, precipitating on δ/γ and δ/δ interfaces. The DL-EPR （Double loop electrochemical potentiokinetic reactivation） results have shown an increase of the DOS （degree of sensitization） for long periods of time on heat treatment. The results of potentiodynamic polarization showed a reduction of the corrosion and pitting potentials, followed by an increase of the current density when the UNS S31830 steel is heat treated during long periods of time.

Effects on Microstructure and Properties of Brass Treated by Laser Shock Processing

Laser shock processing （LSP） has been proposed as a new surface treatment for improving hardness, wear resistance and fatigue. In this paper, the effect of LSP on brass is investigated with experiment. Micro-hardness, roughness, microstructure, wear resistance and friction coefficient evolution are investigated for different parameters of LSP. The result shows that the roughness increases after LSP; no ablation is observed; the microstructure has no remarkable ehange; hardness and the wear resistance increase as the pulse density increases.

Large Area Flat-screen Liquid Crystal Television

A modular flat-screen liquid crystal television display is described.The picture elements of the modules may be emissive,reflective or transmissive.The flat-screen liquid crystal television also comprised of an electrical control circuit capable of categorizing incoming television picture signals corresponding to the modules in the array and directing the electrical signals to the drive circuits of each module according to the portion of the television picture to be reproduced by the picture elements of that module.The picture elements are preferably formed in a light modulating film composed of a liquid crystal dispersion in a polymeric binder.A color display was also produced by placing a patterned red-green-blue filter adjacent the active matrix so that each picture element could also be coordinated with the color components of a color video signal.

Large Area Flat-screen Liquid Crystal Television(continued 1 )

A modular flat-screen liquid crystal television display is described. The picture elements of the modules may be emissive, reflective or transmissive. The flat-screen liquid crystal television also comprised of an electrical control circuit capable of categorizing incoming television picture signals corresponding to the modules in the array and directing the electrical signals to the drive circuits of each module according to the portion of the television picture to be reproduced by the picture elements of that module. The picture elements are preferably formed in a light modulating film composed of a liquid crystal dispersion in a polymeric binder. A color display was also produced by placing a patterned red-green-blue filter adjacent the active matrix so that each picture element could also be coordinated with the color components of a color video signal.