蜂窝陶瓷表面预处理对催化剂性能的影响

应用溶胶－凝胶技术对蜂窝陶瓷载体进行涂层,以ＣＯ氧化作反应模型,考察了浸渍次数、分散剂及Ｌａ,Ｃｅ,Ｚｒ,Ｙ,Ｃｏ等组分对催化剂活性的影响,同时考察了Ｌａ２Ｏ３对催化剂耐热性能的影响．实验表明:两次浸渍的催化剂活性较高,浸渍原液中加入分散剂提高了催化剂对ＣＯ的氧化活性,使最低完全转化温度降低了１３℃左右．在Ｌａ,Ｃｅ,Ｚｒ,Ｙ,Ｃｏ等组分中,Ｃｅ是最有效的活性助剂,当ＣｅＯ２含量占Ａｌ２Ｏ３涂层的１８%时,催化剂的活性最好．而Ｌａ和Ｚｒ的加入对催化剂活性无明显作用,Ｙ和ＣＯ的加入则降低了催化剂的活性．在７００℃下７ｈ的热老化实验表明:Ｌａ２Ｏ３的加入对催化剂热稳定性无明显影响,但是,１０５０℃温度下２４ｈ热老化后的活性评价表明:Ｌａ２Ｏ３的加入对催化剂热稳定性作用显著,与未加Ｌａ２Ｏ３的催化剂相比,最低完全转化温度降低了１５℃左右．     

基于神经网络的岩体边坡稳定性的灰色聚类空间预测法及其应用

针对岩体边坡稳定性与影响因素之间的非线性关系,提出了基于神经网络的岩体边坡稳定性的灰色聚类空间预测法,结合实例仿真分析,表明该方法能较好地处理岩体边坡稳定性与影响因素之间的灰色非线性关系,同时,能比较准确地预测岩体边坡的稳定性。     

Iron stability in drinking water distribution systems in a city of China

A field study on the estimation and analysis of iron stability in drinking water distribution system was carried out in a city of China. The stability of iron ion was estimated by pC-pH figure. It was found that iron ion was unstable, with a high Fe （OH）3 precipitation tendency and obvious increase in turbidity. The outer layer of the corrosion scale was compact, while the inner core was porous. The main composition of the scale was iron, and the possible compound constitutes of the outer scale were α-FeOH, γ-FeOOH, α-Fe2O3, γ-F2O3, FeCl3, while the inner were Fe3O4, FeCl2, FeCO3. According to the characteristics of the corrosion scale, it was thought that the main reason for iron instability was iron release from corrosion scale. Many factors such as pipe materials, dissolved oxygen and chlorine residual affect iron release. Generally, higher iron release occurred with lower dissolved oxygen or chlorine residual concentration, while lower iron release occurred with higher dissolved oxygen or chlorine residual concentration. The reason was considered that the passivated out layer of scale of ferric oxide was broken down by reductive reaction in a condition of low oxidants concentration, which would result more rapid corrosion of the nine and red water phenomenon.     

关于进一步完善我国作业场所职业卫生监管机制的研究

在研究分析我国作业场所职业卫生监管现状,学习和借鉴国外成功经验的基础上,针对我国当前作业场所职业卫生监管工作机制存在的主要不足,提出从4个方面进一步完善我国作业场所职业卫生监管工作机制的建议,即"建立涵盖职业安全卫生内容的三方协商机制;完善职业卫生法律法规与标准体系;确立'国家监察、企业负责、中介服务、群众监督、劳动者遵章守纪'的职业卫生监管工作机制;完善作业场所职业卫生监管相关的若干保障体系"。笔者有针对性地提出4方面建议,以期为政府主管部门学习和借鉴国际通常做法提供参考,进一步提高我国作业场所职业卫生监管的水平,从而实现我国作业场所职业卫生监管工作的有序与高效的发展。     

军事装备使用风险初探

装备的安全使用是部队安全和战斗力的重要组成部分。由于装备复杂性和使用环境的严酷性,使装备使用过程存在较大的风险性。本文提出了装备使用风险的概念,装备使用风险是装备事故可能性与后果严重度的度量,并划分了风险类型。重点对装备使用风险的特点、影响和因素进行了分析,认为装备使用风险因素复杂,对部队安全和任务的完成有重大影响,需要进行风险管理和控制。最后,讨论了装备使用风险管理的原则和要求,以期促进部队装备安全使用和风险管理工作,从而提高部队的战斗力。     

集散控制系统作业安全人机环工程研究

为了解集散控制系统作业安全人机环工程中存在的匹配情况,采用自制《集散控制系统作业安全人机环工程》调查表,对某石化企业390名DCS作业人员进行了问卷调查。结果85．5％的操作者认为操作室的空气不新鲜,57．4％的操作者认为DCS操作系统的性能不够完善,55．3％的操作者认为DCS操作劳动强度大,90．5％的操作者认为DCS显示屏产生直接眩光,87．2％的操作者认为下肢活动空间过小,85．2％的操作者认为下肢活动深度过浅,72．7％操作者认为下肢活动高度过低,56．6％的操作者认为装置区的噪声对控制室有影响。由此得出结论,集散控制系统在人-机-环诸方面不同程度的存在失配。     

某高尾矿坝设计期渗流与稳定分析

针对某上游式高尾矿坝,采用经验类推方法概化了尾矿坝沉积地层分布。根据经验及相关勘察报告估计了尾矿坝不同分区渗透系数,采用二维及三维有限元方法计算了尾矿坝在汛期和正常运行期不同干滩长度条件下渗流场分布,分别对堆积坝分段变坡及初期坝外甩尾碎石所形成的大型反压平台对渗流场及抗滑稳定的影响做了评估,给出了尾矿坝在不同工况下的渗透稳定性评估结果及抗滑稳定安全系数,为尾矿坝设计提供了依据。     

基于VEGETATION数据的区域生态系统质量评价之一——指标体系选择

目前,环境资源问题已经对我国建设"和谐社会"构成了严重挑战,如何选取合适的评价指标体系和构建生态评价模型对生态系统进行准确的评价是困难的,也是十分必要的.从生态系统的平衡、波动、干扰及阈值等基本特点出发,构建了区域生态质量评价指标体系包括生产能力指数、服务功能的稳定度指数和人口压力指数三大指标.     

Introduction of Relative Abundance Distribution (RAD) Indices, Estimated from the Rank-Frequency Diagrams (RFD), to Assess Changes in Community Diversity

Quantifying a relative abundance distribution based on thesampling of a set of species is a widespread problem in ecology.A number of diversity indices have been proposed and used in numerous works in spite of a lack of statistical characteristics and tests of comparison. The relative abundancedistribution can also be described using rank-frequency diagrams but fitting these diagrams to mathematical models such as the Zipf-Mandelbrot model remains problematic. Strong correlation between the Zipf-Mandelbrot model parameters prevent their estimation by optimization algorithm. In light of this, new indices of sampled communities are introduced here. These indices are two linear regression slopes estimated from rank-frequency diagrams. The numerous statistical studies that have been carried out on linear regression models are used to compare sampled communities. These new indices possesscharacteristic properties with an ecological meaning.Correlations between these indices, the Zipf-Mandelbrot modelparameters and an evenness diversity index are examined. Anecological application is made using entomological data as anexample. This example consists of a transect from the edge of apond to a dry forest along which 60,000 insects were sampledfrom six different sampling stations. Using the new indicesdescribed here, station C, located at the edge of that areasubject to influence from the pond, is differentiated from theother stations. This station would seem to present the lowestdegree of niche diversity and the lowest evenness, and recent observations confirm the deterioration of this station.     

牡蛎中多环芳烃(PAHs)标准物质的研制

介绍了牡蛎中多环芳烃标准物质的研究、制备方法 ,进行了均匀性检验、稳定性检验 ,统计计算了检验结果 ,基本确定主要参数。检验结果表明 ,研制的牡蛎中难降解有机物标准物质均匀 ,在一年保存期间内稳定 ,可用于海洋环境监测中