测定化学物对乙酰胆碱酯酶抑制毒性的微板吸光法研究

随着化学污染物种类与数量的日益增多,高通量测试方法显得越来越重要。基于乙酰胆碱酯酶(ACh E)抑制法原理,以多功能酶标仪为测试设备,96孔微板为暴露反应载体,建立了测定化学物对ACh E抑制毒性的微板吸光法。系统研究了ACh E浓度、碘化硫代乙酰胆碱(ATCI)浓度、二硫代二硝基苯甲酸(DTNB)浓度对显色吸光度、吸光度变化速率、化学物测试毒性的影响。结果表明,随着ACh E、DTNB、ATCI的浓度增加,吸光度均增加;吸光度变化速率与ACh E浓度呈正相关,与DTNB浓度基本无关,与ATCI浓度呈现先增后减的双相关系;随着ATCI浓度增加,灭多威剂量-效应曲线(DRC)向右移动。最终建立的优化测试条件为DTNB 0.2 g·L~(-1)、ATCI 0.2 g·L~(-1)、ACh E 0.04 U·m L~(-1)、p H 6.8、反应温度29℃及暴露时间15 min;并与国标方法进行了对比与验证,发现试剂加样顺序对毒性测定结果有显著影响。基于ACh E的微板毒性测试结果表明,灭多威的DRC呈现良好的S型曲线,可用Weibull函数有效表征,拟合决定系数R2大于0.97,空白变异控制在了±10%以内。此方法可用于化学污染物的高通量毒性检测。     

资源环境基础论:中国人地关系研究的出发点

尽管已经跨入现代化发展的门槛,但是作为地球表层的一个物种,人类生存与发展的第一需求依然是最大限度地获取物质消费的满足。实际上,随着社会财富和人口的快速增长,与资源环境的协调已经成为各国持续发展的首要任务和基本目标。这种协调既是可持续理论也是人地关系研究的核心所在。作为世界上人类文明发育最早的国家之一,中国的实践再次表明,资源环境的空间格局变化始终是决定国家人口活动基本方向的基础所在。资源环境要素综合评价和人地关系模式的分析结果表明,东部(偏南)地区始终是中国国家人文活动的重心所在,而决定这一空间格局变化的正是国家和区域的资源环境状态。因此,认识资源环境的基础作用,是中国持续发展的基本出发点。     

跨区资源调配工程的区域利益关系探讨——以西电东送南通道为例

目前,我国跨区资源调配工程双方的区域利益关系尚未完全理顺,区域利益矛盾存在并有进一步激化的可能。西电东送南通道双方在价格水平与增长趋势、送电曲线和生态补偿等方面存在较大分歧,当前的资源交易与区域利益分配模式存在不合理的因素。西电东送的特殊性需要由市场和政府共同承担协调区域利益关系的任务,市场化是西电东送的必然取向,但政府应在体现西电东送综合效益、潜在效益和隐性效益及促进区域协调发展等方面发挥作用。     

从"两条主线论"考察中国文明进程

以可持续发展理论审视,在中国文明的发展进程中,除了存在传统史学所强调的“人与人”的关系这条主线外,还存在着“人与自然”关系的主线,本文以中国的若干重大历史事件为例证,初步论证了“人与人”和“人与自然”两条主线的相互作用关系是中国文明发展演变的主要驱动力。因此,实现人与人关系的公平和人与自然关系的和谐,是实现可持续发展的前提。     

PROMOTING GROUND WATER POLLUTION PREVENTION IN SMALL BUSINESSES1

ABSTRACT: Although they have not been the focus of major regulations, small businesses can contribute pollutants to ground water through routine practices. Because strict regulation of millions of micro firms is not likely, water resource professionals face a challenge of how to reach small business operators with effective pollution prevention messages. The purpose of this study was to examine the factors that influence a small business operator to adopt measures that reduce potential ground water pollution. We looked at how information delivery, internal business characteristics, and external relationships are associated with voluntary preventive measures. Mail surveys from small businesses in New Jersey municipalities and interviews with business owners provided data about business characteristics and current pollution prevention activities. Findings suggested that businesses doing the most to prevent ground water pollution were generally more connected to external organizations and had more financial and technical resources. The study also discovered that small business owners fear government involvement in their affairs. The study concludes with recommendations to encourage more voluntary adoption of prevention measures by businesses. These center on separating assistance programs from enforcement and involving industry peer groups in an effort to make information available in a non-threatening manner.     

Identifying Determinants of Nations' Wetland Management Programs Using Structural Equation Modeling: An Exploratory Analysis

Integrated management and policy models suggest that solutions to environmental issues may be linked to the socioeconomic and political characteristics of a nation. In this study, we empirically explore these suggestions by applying them to the wetland management activities of nations. Structural equation modeling was used to evaluate a model of national wetland management effort and one of national wetland protection. Using five predictor variables of social capital, economic capital, environmental and political characteristics, and land-use pressure, the multivariate models were able to explain 60% of the variation in nations' wetland protection efforts based on data from 90 nations, as defined by level of participation in the international wetland convention. Social capital had the largest direct effect on wetland protection efforts, suggesting that increased social development may eventually lead to better wetland protection. In contrast, increasing economic development had a negative linear relationship with wetland protection efforts, suggesting the need for explicit wetland protection programs as nations continue to focus on economic development. Government, environmental characteristics, and land-use pressure also had a positive direct effect on wetland protection, and mediated the effect of social capital on wetland protection. Explicit wetland protection policies, combined with a focus on social development, would lead to better wetland protection at the national level.     

太湖流域水环境演变与人类活动耦合关系

太湖流域水环境与人类活动之间存在相互制约、相互作用的关系。从 2 0世纪 6 0年代起 ,随着经济的发展、工业化与城市化进程的加速 ,流域水环境不断恶化 ,具有表征意义的太湖水体的TP ,TN ,COD浓度不断上升。本文把环境演变的人文驱动因素归纳为人口发展、经济发展、城市化、土地利用等 ,将其与太湖流域水环境耦合 ,得出探讨性结论 :太湖流域人类活动与水环境之间的互动关系大致经历了干预、干预—弱制约、干预—制约、干预—强制约四个阶段 ,每个阶段对应着不同的人类活动特征。流域水环境恶化经历了几十年 ,而水环境修复则需要人类更长时期的共同努力     

REVERSIBLE ADSORPTION OF AQUEOUS DIVALENT COPPER ION BY ESTUARINE SEDIMENTS1

Sediments were equilibrated with solutions containing divalent copper ion. A colorimetric method using the triethylenete-tramine complex of the metal ion was employed to measure changes in uptake of copper by the sediments. Studies were made with sediments from rivers in the British Isles which were in the proximity of areas which had been mined for metals for several hundred years. For comparison, similar studies were performed with a sample of sand and a soil with a high organic content. It was possible to follow the uptake of copper ion by the materials and estimate their abilities to adsorb copper ion. In particular, a strong correlation was observed between the organic content of the sediment and the total amount of copper adsorbed by the sample. Under the employed circumstances it was possible to demonstrate that the adsorption of the metal ion was reversible.     

乌江中上游底栖硅藻群落与阴阳离子、重金属间的关系

首次对乌江中上游底栖硅藻群落组成特点进行定量系统研究,得知其组成基本上呈种类多、丰度小,种类少、丰度大的分布状况。对底栖硅藻丰度和八种离子、重金属间关系进行定量分析后知Hg元素是影响底栖硅藻丰度的第一显著因子,建立了底栖硅藻丰度-汞元素曲线回归方程。可为用硅藻监测、评价河流水质提供理论基础,并为水质预警的硅藻生物指标的研究提供科学依据。     

新疆绿洲生态环境与经济发展的协调关系分析

建立新疆绿洲生态环境质量综合评价指标体系和经济发展水平综合评价指标体系,利用熵值法分别测度2000年-2010年新疆绿洲生态环境质量综合水平和经济发展综合水平,在此基础上利用协调模型,测度两者的协调度和协调发展度,进而分析两者的协调关系。分析结果显示:新疆绿洲生态环境质量综合水平缓慢下降,经济发展综合水平不断上升;两者的协调关系从中级协调-优质协调-中级协调,协调发展度表明两者的协调处于相对低层次的协调。