The Mechanism of Crack Formation in Rubbers under the Effect of Ozone

Abstract

The formation and growth of cracks under an effect of ozone were investigated in different types of rubbers, such as NR, PBR, BMSR, SBR and in composite materials based on these rubbers. The study was carried out by the reflection-light optical microscopy method with using the MMP-4 microscope. In the presence of microinhomogeneities in a surface structure the crack formation is shown to start from those defects. In the absence of inhomogeneities the cracks are formed uniformly over the whole surface of a specimen. It is found that even insignificant quantities of low-modulus rubber in the PBR-based composite material may result in changing the shape of a crack during its growth. An attempt is undertaken to describe the shape of formed cracks quantitatively. The calculational and experimental data are presented.

The influence of deformation on the number of cracks per surface unit, on their shape, geometrical size, cracking degree is studied for example of natural rubber specimen.     

超高分子量聚乙烯微孔膜的亲水改性研究——（I）臭氧活化接枝反应及其表征

利用O3处理超高分子量聚乙烯（UHMWPE）微孔膜，使其表面产生活性点，然后将甲基丙烯酸（MAA），甲基丙烯酸羟乙酯（胍MA）接枝在膜表面上．用ATR—FTIR、XPS等对O3活化及接枝前后的UHMWPE微孔膜结构进行了表征，接触角测试表明接枝后微孔膜具有较好的亲水性．     

Crystallographic Orientation Dependence of the Schottky Properties of Au/SrTiO3 Junctions

Crystallographic orientation dependence of the Schottky properties of Au/Nb-doped SrTiO₃ (STO:Nb) junctions has been investigated using single crystals of STO:Nb (1 0 0) and (1 1 1). It is found from electrical properties that the Schottky barrier height (SBH) of the Au/STO:Nb junctions estimated from current density (J)-voltage (V) characteristics shows crystallographic orientation dependence, while the flat band voltage estimated from capacitance (C)-voltage (V) characteristics is independent of the orientation. Displacement currents originated from the junction capacitance have been clearly observed at reverse bias voltage even in a condition of dV/dt 8.75 × 10^–3 [V/s] because of large electrostatic permittivity of the STO, and the displacement currents also showed crystallographic orientation dependence. The different response in the electrical properties of the Schottky junctions suggests that electric properties of intrinsic low permittivity layers, which exist at Au/STO:Nb interfaces, have the crystallographic orientation dependence.     

纯水生产中O3的在线管道氧化工艺

本文介绍了一种盘管在线式臭氧接触氧化处理RO纯水工艺。三年多的运行实验和一系列分析测试数据表明，该工艺用于RO纯净水生产具有投资少、几乎不占场地、臭氧气－液传质效率高、成品水中溶解氧含量高、免维修保养等优点，适用于饮用水少有关饲料生产中的消毒、杀菌和杀灭藻类，尤其是适合规模较小的生产厂家。     

Conductometric determination of sulfur in organic substances

A conductometric method is considered for determining sulfur contents in organic substances, in particular in diesel fuel. Ozone is proposed for oxidizing sulfur dioxide.Translated from Izmeritelnaya Tekhnika, No. 9, pp. 19–22, September, 2004.     

A method for assessing the effect of water quality changes on plumbosolvency using random daytime sampling

The Mann-Whitney U-test is used to demonstrate the impact of phosphate on lead concentrations measured at customer properties. This test is statistically robust and particularly efficient for the type of distributions encountered in lead random daytime sampling. This non-parametric technique is developed to provide a best estimate of the lead reduction that results from a change in plumbosolvency conditions. The method is illustrated with compliance data collected before and after the introduction of phosphate at customer properties in the north west of England. Limitations due to operational factors are highlighted. Using a Monte Carlo simulation of the variability of lead random daytime samples it is shown that the method might be practical when assessing the impact of incremental changes in phosphate concentration on plumbosolvency.     

分层模糊控制器在水厂混凝投药过程中的应用

水厂混凝投药过程在给水处理中占有重要的地位,直接关系到出水水质;而这一过程具有非线性、大滞后、多变量等特点,针对这一情况,提出了运用分层模糊控制器来实现混凝剂的最佳投加;论述了分层模糊控制器的设计原理和设计方法,并将其应用于水厂混凝投药这一具体过程;通过Matlab软件对水厂实际数据进行了仿真,结果表明这一方法不但有效可行,而且能避开复杂的数学模型,节约内存资源和计算时间,还能降低劳动强度,减少人为的操作失误,提高控制水平.     

气相中二甲苯的臭氧和光降解研究

用紫外线、臭氧降解气相中二甲苯(邻、间、对二甲苯),分别考察了在不同的反应条件下二甲苯的降解情况。比较了在空气或氮气的不同反应系统中二甲苯的降解情况,并对二甲苯在空气中的光降解产物及其反应历程进行了探讨;实验结果表明,在相同条件下邻二甲苯的光降解速率最大,二甲苯的光降解过程中都有中间产物生成。     

一种适用于臭氧发生器的变频电源的设计与分析

提出了一种主电路采用IGBT全桥结构，驱动电路采用M57962L模块，利用单片机控制技术的高频逆变电源的设计方法，同时对电路的工作原理作了分析与仿真，该电源系统为小型化和智能化臭氧发生器电源的研究提供了基础。     

基于专家控制器的水厂加氯串级控制系统

水厂加氯消毒是保证自来水品质的关键环节之一。由于加氯系统具有大时延和时变性的特点,加之系统的干扰因素较多,常规的PID控制器往往难以胜任。采用专家控制与传统串级控制相结合的加氯系统自动控制方案,能有效地解决上述问题。在工程上,通过将该方案与PLC和组态软件技术相结合,成功实现了对南京市某水厂加氯工艺的自动控制,并取得了良好的控制效果。