Degradation kinetics of 2,4-dichlorophenol by gamma ray irradiation in the presence of ozone

Gamma ray-induced degradation of 2,4-dichlorophenol(DCP) in the presence of ozone has been investigated.The results show that ozone can remarkably increase the degradation rate of 2,4-DCP in aqueous solution.The degradation kinetics of 2,4-DCP can be described by the first-order reaction model,and the rate constant was0.443,0.490 and 1.247 h~(-1),respectively,for γ-ray irradiation only,γ-ray irradiation+13 mg/L O_3 and γ-ray irradiation+30 mg/L O_3.High-performance liquid chromatography analysis shows that the dechlorinated products are 4-chlorophenol,2-chlorophenol and phenol;and the oxidation products are hydroquinone,benzoquinone,maleic,fumaric,acrylic,malonic,oxalic,acetic and formic acids.The possible pathways for 2,4-DCP degradation involving all these oxidation products are tentatively proposed.Combining γ-ray irradiation with ozonation is a promising technology for removing toxic pollutants from water and wastewater.     

汽车半轴锥齿轮的精密成形技术和机加工专用夹具研究

提出了采用普通锻压设备进行坯料准备、高精度冷摆辗机成形半轴锥齿轮精锻件的成形新工艺,研究了成形工步的坯料形状、成形工艺参数、模具结构以及精锻件后续加工的工装夹具结构等一系列技术问题。达到了齿形精度高、齿部强度高、啮合质量好、齿轮模具的使用寿命高、材料利用率高、生产成本降低及可以进行大批量工业生产的目的。     

Coupling solar photo-Fenton and biotreatment at industrial scale: main results of a demonstration plant

This paper reports on the combined solar photo-Fenton/biological treatment of an industrial effluent (initial total organic carbon, TOC, around 500mgL(-1)) containing a non-biodegradable organic substance (alpha-methylphenylglycine at 500mgL(-1)), focusing on pilot plant tests performed for design of an industrial plant, the design itself and the plant layout. Pilot plant tests have demonstrated that biodegradability enhancement is closely related to disappearance of the parent compound, for which a certain illumination time and hydrogen peroxide consumption are required, working at pH 2.8 and adding Fe(2+)=20mgL(-1). Based on pilot plant results, an industrial plant with 100m(2) of CPC collectors for a 250L/h treatment capacity has been designed. The solar system discharges the wastewater (WW) pre-treated by photo-Fenton into a biotreatment based on an immobilized biomass reactor. First, results of the industrial plant are also presented, demonstrating that it is able to treat up to 500Lh(-1) at an average solar ultraviolet radiation of 22.9Wm(-2), under the same conditions (pH, hydrogen peroxide consumption) tested in the pilot plant.     

通用智能积算仪

本文介绍一种采用单片计算机的集比例、开方、补偿三种积算仪功能于一体的通用智能流量积算仪。它具有结构简单、通用性强、精确度高、调校使用方便等优点。     

工业废水处理新技术与新方法的研究进展

概述了目前国内外工业有机废水治理现状、研究进展及其发展趋势,分析了高级氧化技术和生物处理技术的原理及特点,重点论述了液相高压脉冲放电技术、激光诱变育种技术及高级氧化-生化耦合技术的特点、现状及应用前景,指出今后应从实验、理论和数值模拟三方面开展高级氧化-生化耦合化工过程的集成优化技术研究。     

“固定相差分段” “多积分”捕获方案

文章根据“固定相差分段捕获”和“顺序多积分捕获”原理,提出了一种直接序列扩频通信系统中新的PN序列捕获方案,并给出了实现框图及工作过程说明。     

Information management in process-based organizations: a case study at Xerox Ltd

Abstract. The process-oriented holistic enterprise is a new organizational form in which the business process may be perceived as the basic organizational construct. Process management on an enterprise-wide scale implies a complex integration of business processes. The increased organizational complexity places heavy demands on a firm's information management capability, and this needs to be managed in a way that best supports the process model. This research has found that in the case of Xerox Ltd, a company that has adopted a holistic approach to process management, the information management process is key to supporting this method of organizing. The main finding is that, in order to support process management, a particular type of information management is required. This includes a need for enterprise-wide information systems and the centralization of systems development and maintenance. However, the process management is made possible by this type of information management. This may be referred to as the duality concept of information and process management. The research presents findings from an in-depth participant observation study conducted at the Xerox Ltd headquarters in the UK, and also includes data collected from Xerox France and Xerox UK.     

Microstructure development during constant-force drawing of poly(ethylene terephthalate) film

Structure development in PET film during high strain-rate, constant-force (CF) deformation in the temperature range 80–96°C is compared with structure development during lower strain rate, constant-extension-rate (CER) deformation in a similar temperature range. The higher (maximum) strain rates involved in CF drawing mean that much of the deformation takes place in a regime where the time available for orientational relaxation and crystallization is short. This results in high levels of ‘non-crystalline orientation' and low levels of crystallinity compared to structures obtained from CER drawing. In CER drawing, due to the lower strain rates, the degree of crystallinity always has time to reach pseudo-equilibrium values corresponding to a given level of non-crystalline orientation, and the amount of orientational relaxation occurring during drawing has the dominant influence on structure development. In CF drawing, pseudo-equilibrium crystallinity values are not reached, except when the deformation approaches the tail-end of the strain-rate spectrum. The results also provide confirmation that microstructure data obtained from rapidly quenched samples are consistent with microstructure data obtained from real-time experiments.     

On the Optimal Segment Length for Parameter Estimates for Locally Stationary Time Series

We discuss the behaviour of parameter estimates when stationary time series models are fitted locally to non-stationary processes which have an evolutionary spectral representation. A particular example is the estimation for an autoregressive process with time-varying coefficients by local Yule–Walker estimates. The bias and the mean squared error for the parameter estimates are calculated and the optimal length of the data segment is determined.