鱼尾型机头中熔体流动的三维流场分析

本文利用ANSYS和MATLAB软件，对鱼尾型片材机头中熔体的速度、压力、剪切应力和粘度的分布进行三维有限元模拟和分析。探知了熔体在流道内的运动规律及特点并分析其原因，对口模设计具有定的指导作用。     

N-甲基乙酰氧基乙酰苯胺的液谱分析

本文研究了高效液相色谱测定N－甲基乙酰氧基乙酰苯胺的方法。采用Hypersil C18柱，以甲醇：水＝60：40（V／V）为流动相。该方法的变异系数为0．43％，回收率为98．9％－100．6％。     

Using ontology-based text classification to assist Job Hazard Analysis

The dangers of the construction industry due to the risk of fatal hazards, such as falling from extreme heights, being struck by heavy equipment or materials, and the possibility of electrocution, are well known. The concept of Job Hazard Analysis is commonly used to mitigate and control these occupational hazards. This technique analyzes the major tasks in a construction activity, identifies all potential task-related hazards, and suggests safe approaches to reduce or avoid each of these hazards. In this paper, the authors explore the possibility of leveraging existing construction safety resources to assist JHA, aiming to reduce the level of human effort required. Specifically, the authors apply ontology-based text classification (TC) to match safe approaches identified in existing resources with unsafe scenarios. These safe approaches can serve as initial references and enrich the solution space when performing JHA. Various document modification strategies are applied to existing resources in order to achieve superior TC effectiveness. The end result of this research is a construction safety domain ontology and its underlying knowledge base. A user scenario is also discussed to demonstrate how the ontology supports JHA in practice.     

乙烯装置长周期运行安全风险分析与对策

分析了中国石化茂名石化公司化工事业部乙烯装置长周期运行的安全风险,讨论了风险控制措施。结果表明:乙烯装置连续运行6年,其安全风险属于可容许风险。     

Modified Indigo Method For Gaseous And Aqueous Ozone Analyses

The indigo method developed by Bader and Hoigné for aqueous ozone analysis was modified to allow for both gaseous and aqueous ozone determination. Gas or water samples were extracted with a gas-tight syringe containing a known volume of indigo reagent. The modified procedure provided a more consistent basis for gaseous and aqueous ozone determination allowing for more accurate ozone mass balance calculations. Direct gaseous ozone UV absorbance with molar absorptivity of 3,000 M^?1cm^?1 at 258 nm was used as primary standard to determine the molar absorptivity of the indigo reagent. The molar absorptivity of indigo reagent, assuming a 1:1 stoichiometric ratio for the reaction between indigo and ozone, was determined to be 23,150 ± 80 M^?1cm^?1, or approximately 16 percent higher than that of 20,000 M^?1cm^?1 suggested by Bader and Hoigné. An independently calibrated membrane-electrode ozone monitor showed good correlation with indigo method results using the molar absorptivity value determined in this study. The apparent molar absorptivity of aqueous ozone at the wavelength of 258 nm measured by the modified indigo method increased from 2,400 to 3,600 M^?1cm^?1 in the investigated ozone concentration range of 0.4 to 11.0 mg/L. This variation might have been caused by the inherent interference of unidentified ozone byproducts, which presence was supported with scanning spectra in the wavelength range of 200 to 300 nm.     

2D12型往复式压缩机气阀故障诊断的时频分析方法

分析了 2D12型往复式压缩机气阀的工作过程 ,针对气阀工作特点提取吸气阀与排气阀均关闭时刻的压缩阶段的局域声音信号 ,应用广义双线性时频法诊断气阀故障 ,给出了正常气阀和故障气阀的时频分析图     

Internal fracture of notched epoxy resins

The brittle fracture of round-notched epoxy resin bars subjected to plane strain bending has been studied at varying strain rates. Observations of fracture processes and surface morphologies revealed that the internal crack was nucleated at the plastic-elastic boundary when the plastic deformation zone at the notch root reached a certain size. A slip-line field theory allows calculation of the stress components at the plastic-elastic boundary from a knowledge of the location of the internal crack. An analysis of the data concluded that the triaxial stress level ahead of the plastic zone was raised by plastic constraints to an ideal fracture stress which is considerably larger than that of glassy thermoplastics.     

论搜索软件对网络安全的影响

随着我国互联网技术的快速发展,我们今天的学习、工作和生活各个方面都离不开互联网技术的支撑,互联网技术对我们每一刻都会产生很大的影响,那么随着互联网技术的发展,搜索软件也逐渐占领了一席之地,并且在发展过程中,逐渐渗透到了网络中心的每一个角落,对于互联网技术的发展带来很大的影响.在这些网络发展和利用过程中,很多的私人信息、重要数据等成为了病毒或者是黑客的攻击对象,那这些行为对于网络的安全使用带来了很大的威胁,因此正确的认识到这些漏洞所在,针对搜索软件对于网络安全使用的影响效果进行分析探讨,从而提出有效的解决方式来提高网络的安全使用性能.     

乙烯收率状况分析与对策

通过对广州石化乙烯厂裂解原料、收率、运行状况进行分析，揭示石脑油质量波动对乙烯收率的影响，研究了乙烯收率的偏低原因，并提出原料频繁变化条件下，原料优化运作和COT调整对策。     

GC/MS characterization of effluents front the ozone bleaching of eucalypt kraft pulps

Concerns regarding the possible environmental effects of organochlorine by‐products from bleaching of pulp with chlorine‐based compounds have led to the pulp and paper industry developing new bleaching sequences. Ozone, oxygen and hydrogen peroxide are the main reagents in these Totally Chlorine Free (TCF) bleaching processes.

In this study, eucalypt kraft pulps from a variety of Australian wood sources were subjected to bleaching sequences comprising oxygen, ozone and hydrogen peroxide/alkali extraction stages. The aqueous liquid effluents from each stage were analyzed by GC/MS for aldehydes, ketones, alcohols, carboxylic acids and other by‐products. Pentafluorobenzyl oxime derivatives of the aldehydes and ketones were analyzed by electron impact GC/MS. The major carbonyl compounds detected were formaldehyde, glyoxal, dimethylglyoxal and acetone. An homologous series of n‐aldehydes corresponding to cleavage of ω‐3, 6, 9 and 12 unsaturated fatty acids also was detected. Aromatic aldehydes were identified in the oxygen stage and high consistency ozone stages, but not in any medium consistency ozone or post‐ozone bleach stages. In all stages a series of saturated alkyl carboxylic acids from formic to octacosanoic acid was detected. Formic and acetic acids were present in the highest yield. Only trace quantities of unsaturated fatty acids were detected. Details of these and other compounds detected are discussed.