大型锻件热处理过程的数值模拟研究

在对大型锻件传热分析的基础上 ,建立了大型锻件的物理模型 ,对其温度场的变化规律进行了模拟计算 ,同时将模拟结果和实验结果进行对比分析 ,最后利用模拟计算对材料为 2 6Cr2Ni4MoV的某一电机转子的调质处理进行了模拟计算 ,从而说明了热处理过程的数值模拟方法的准确性和优越性。为进一步分析此类工件的组织转变和应力应变等奠定了基础。     

大型锻钢支承辊锻后热处理工艺优化实践

根据近 1 0 0支锻钢支承辊的锻后热处理的工艺实践 ,摸索出了一套此类支承辊的锻后热处理工艺 ,缩短了生产周期 ,提高了效率 ,降低了成本 ,保证了质量。     

土壤环境中阴极保护电位对涂层的影响

通过电化学测试手段,研究了土壤中涂覆有涂层的钢样在不同阴极电位下的阴极极化行为,并探讨析氢阴极还原反应对涂层的影响,从而为阴极保护限制电位的确定提供依据。     

电网电能质量分析评价技术研究（续）

文中论述电能质量分析及其评价准则,电力谐波问题及其治理技术。     

一种可用于低COD石化废水处理的新型树脂

为了对低COD的石化废水进行深度处理,通过乳液聚合法将苯乙烯、丙烯酸丁酯、可聚合季铵盐进行三元共聚,以一步法合成了一种新型聚苯乙烯（PS）微球吸附树脂。采用IR、SEM、BET等手段对树脂进行表征,并与市售吸附树脂D301、XAD⁃4、NDA⁃150进行了结构和性能的对比。结果表明,合成树脂呈不规则球形,直径在0.2~0.4 mm,24 h内可将石化二级废水的COD从100 mg/L降至20 mg/L以下。该树脂对石化废水的吸附行为接近单分子层的吸附,饱和吸附量达到89.0 mg/g,高于市售树脂D301(85.5 mg/g)、NDA⁃150(30.4 mg/g)以及XAD⁃4(58.8 mg/g)。臭氧氧化再生结果表明,合成的PS树脂可循环再生4次以上,较其他几种传统的吸附树脂具有更好的再生性能。该材料可以作为处理石化废水的良好吸附剂应用于低COD废水的深度处理工艺中。     

Ozone based food preservation: a promising green technology for enhanced food safety

Extending shelf life of food products is a major concern of the producers, and the food industry requires ‘greener’ alternatives to the current technologies. Ozone-based food preservation may suit this niche. Ozone is an attractive alternative preservative that food industry needs due to its properties such as quick decomposition and little residual effect during food preservation. Ozone is the strongest molecule available for the disinfection of water and is second only to elemental fluorine in oxidizing power. Ozone is being used in the food industry in various applications such as decontamination of water and equipment surfaces. Several researchers have focused on the application of ozone to inactivate microorganisms on fresh produce, like fruits, vegetables, meat, poultry, fish, and eggs, and dry produce, such as cereals, pulses, and spices. This review comprehensively analyses appropriate ozone concentrations and exposure times and discusses various factors that affect the quality and safety of food products during ozonation.     

Ozone Synthesis and Decomposition in Oxygen-Fed Pulsed DBD System: Effect of Ozone Concentration,Power Density,and Residence Time

The process of ozone production in pure oxygen was studied. It was shown how the ozone concentration changes along the discharge gap, both during its generation and decomposition processes. The effect of ozone inlet concentration, power, and gas residence time on ozone concentration was analyzed. It has been shown that concentrated ozone is easily decomposed at very low discharge powers, i.e., when the increase of the average gas temperature in the gap is negligibly small. It was hypothesized that the most intense decomposition takes place in the microdischarge channels, because the process of gas heating in the gap begins inside them.     

Highly active OMS-2 for catalytic ozone decomposition under humid conditions

Four kinds of cryptomelane-type octahedral molecular sieve(OMS)-2-X(the X represents the molar ratio of KMnO_4/MnAc_2) were prepared as catalytic materials for ozone decomposition through a one-step hydrothermal reaction of KMnO_4 and MnAc_2, by changing their molar ratios. These samples were characterized by N_2 adsorption–desorption, X-ray di raction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), temperature programmed reduction by H_2(H_2-TPR) and X-ray photoelectron spectroscopy(XPS). Among them, the OMS-2-0.7 sample showed the best O_3 conversion of 92% under high relative humidity(RH) of 90% and gas hourly space velocity of 585,000 h-1. This was accordingly thought as a possible way for purifying ozone-containing waste gases under high RH atmospheres. The e ciency of ozone decomposition of the prepared OMS-2-X sample was found to be related to specific surface area, particle size, surface oxygen vacancies, and Mn~(3+) cation amounts. The one-step hydrothermal synthesis was shown to be a simple method to prepare the considerably active OMS-2 solids for ozone decomposition.     

高压直流接地极对埋地管道的电流干扰及人身安全距离

高压直流输电系统的直流接地极在运行初期或发生故障和检修时,会产生瞬间大电流,给附近埋地油气管道设施及操作人员带来极大的安全隐患。为了保障埋地管道附近人员的安全,对高压直流接地极对埋地管道的电流干扰及人身安全距离(以下简称安全距离)进行了研究。首先利用数值模拟技术建立了埋地管道受电磁干扰的模型,进而利用该模型计算了不同土壤电阻率、管线长度、管道防腐层、接地极入地电流、管道尺寸等情况下,高压直流接地极对埋地管道杂散电流干扰的安全距离,并分析了上述条件对高压直流接地极干扰程度的影响规律。研究结果表明:①管线长度对高压直流接地极干扰程度的影响较大,管线越长,安全距离越大,但当管线长度达到或超过600 km时,安全距离则基本不变;②管线涂层对高压直流接地极干扰程度的影响较大,随着涂层面电阻率的增加,安全距离逐渐增大;③对于多层土壤结构,可将最大的单层电阻率作为整体电阻率,其计算得到的安全距离最大,评价结果也更为保守。结论认为,利用计算结果得到的4类长度管线的安全距离图谱,可供高压直流接地极及管线设计时参考,并且可以作为拟建高压直流接地极或埋地管线安全距离选取的依据。     

制盐母液中高含量氯化镁提取工艺初探

采用目前的添加熟石灰 絮凝剂对母液中镁进行处理的方式既浪费镁资源,又给环境带来污染,而且还会增加经济成本,如将其进行综合利用或者回收其中大量的镁,不但会降低处理成本,还给企业和社会带来良好的经济效益和社会效益.本文针对自贡大安制盐母液,通过简单的探试试验阐述了提取制盐母液中的高含量氯化镁的工艺,将制盐母液中的镁转化成氯化镁的形式进行提取,以获得较纯的氯化镁产品.