全球十大环境问题

当前或即将为成为全球性的环境问题可归纳为１０类,即臭氧层耗损,温室效应用及全球变暖,酸沉降危害物剧,生物系统简化,土壤退化,森林锐减,水资源危机,海洋环境污染,固体废料的污染和有毒化学污染等。本文对这些环境问题的基本概念,内容,成因,趋势和对人类生存发展的影响,进行了综合分析和论述。     

锦州市生态环境问题及保护对策

本文阐述了锦州市生态环境存在的主要问题,并结合锦州市实际情况及自然概况,提出针对性的保护措施。     

An in-situ method of identifying ingredients of zeotropic refrigerants by inversion problem technique

An inversion method is applied to identify ingredients of zeotropic refrigerants in a circular duct. In the case of low Reynolds number and constant fluid pressure, the temperature distribution of direct heat transfer problem can be solved numerically. The thermophysical parameters of zeotropic refrigerants are determined by using inversion problem technique, the ingredients of refrigerants can be identified eventually. An in-situ experimental apparatus was proposed and three test samples with different composition refrigerants were conducted in this study. The experiment results show that the relative error of ingredients identification can be limited within 8.33%.     

Sharing conservation burdens fairly

We examined how, from the point of view of justice, the burdens of paying for conservation should be shared. I resisted simple answers to the question of who should pay for conservation that lean on a single moral principle. I identified 3 relevant principles that relate to who causes conservation challenges, who has greater capacity to carry burdens, and who stands to benefit from conservation. I argue for a distinctive pluralist framework for allocating conservation burdens that grants a proper role to all 3 principles. A multistep process can be used to put the framework into practice. First, identify cases in which conservation is necessary. Second, consider whether people knew or could have been expected to anticipate the consequences of their activities and whether they had reasonable alternatives to acting the way they did. Third, turn to facts about benefits; when no culprit for conservation challenges can be found, ask who benefits from acts of conservation. In the second and third stages, consideration must also be given to ability to pay.     

Simplified multiple equations' inverse problem of vented vessels subjected to internal gas explosions

This paper analyses the experimental data reported by Höchst and Leuckel (1998) for combustion in partially confined vessels and uses the data from these experiments to establish the burning rate based on a simplified model for the combustion process in such vessels. The model establishes three fundamental parameters which are necessary in characterizing the combustion process. These are: i) the burning rate, ii) the fraction of vent area occupied by burnt gas (or discharge sub-model), and iii) the vent area model (if cover mechanisms with variable vent areas are utilized). A set of independent equations is derived to determine the burning rate according to conservation of mass and volume for each gas fraction separately along with a general equation based on general volume conservation. Using this method we are able to describe the combustion process and examine the effect of various discharge models. The advantages of the model presented here include rapid applicability and a valuable analysis to derive mass burn rate and other useful parameters using experimental data from vented explosions with reasonable residual reactant values. Based on these results, the correct interpretation of the obtained burning rate can be used in order to explain the correct prediction of flame velocity and position according to a reasonable discharge model. The paper also evaluates the suitability of several discharge models for phenomenological models of vented explosions. The most appropriate is a Heaviside step function which considers that only unburnt gas is initially expelled, with that component decreasing and the burnt gas component increasing until finally only burnt gas is expelled. The obtained results in this study can be used to predict the burning rate behavior and the combustion process of similar problems.     

重庆市农业转型发展的时空演进及问题区识别——基于全要素生产率视角

研究农业全要素生产率时空演进规律对于合理制定农业转型升级政策具有重要意义。在使用DEA-Malmquist指数模型测算出重庆市37个县（区）2000-2016年农业全要素生产率增长的基础上,结合空间分析方法和核密度估计方法考察农业TFP的时空演进特征,并识别出问题区域。研究表明：（1）2000-2016年间重庆市农业全要素生产率呈上升趋势,农业TFP指数呈“U”型和阶段性波动的变化趋势,并且表现出明显的空间不平衡性。（2）农业TFP指数增减趋势与技术进步指数的变化趋势基本一致,技术进步是影响农业全要素生产率的主要因素。（3）从全市来看,农业TFP的核密度曲线不断向右移动,且波峰高度持续上升,波峰形态由“单峰”分布向“多峰”分布转变,说明重庆市农业全要素生产率的地区差距在考察期内呈增大趋势。（4）依据TFP增长、技术进步和技术效率的关联关系,识别出三种类型的问题区域,并针对每类问题区域提出农业转型发展的政策建议。     

地表水自动监测预警系统验收应注意的问题

以汇龙地面水厂水质自动监测预警系统为例,提出了水质自动监测预警系统验收中应注意的问题。指出,应在做好预验收工作的基础上,采用性能测试、对比试验、标准溶液核查等技术手段对系统考核验收。     

危险废物填埋场地下水污染风险评价的研究现状

介绍了地下水风险评价的基本概念,综述了国内外危险废物填埋场地下水污染风险评价指标体系和评价方法的研究现状,分析了目前国内危险废物填埋场地下水污染风险评价存在的主要问题,并提出相关建议。     

积业应激对炼钢工人健康的影响及其预防

本文主要介绍了职业应激的概念,以及高温、噪声、辐射、压力这些应激原给炼钢工人健康带来的影响,并提出了预防措施。     

常压热水锅炉的问题分析

详细地分析了常压热水锅炉在制造、安装、使用中出现的问题，有针对性地提出了可行的整改措施。