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211.
从废弃资源特点和价值来源出发,分析了废弃资源正负价值来源,建立基于微观经济基础的循环经济分析框架,分析影响循环经济的近因和远因,并根据系统论及自组织理论,对远因进行分类,提出了影响循环经济的主导因素和次要因素等。 相似文献
212.
生态恢复过程中的种群遗传学考虑 总被引:9,自引:3,他引:6
陈小勇 《长江流域资源与环境》2000,9(3):313-319
生态恢复是生态科学的最终实验,从种群角度看,恢复的目标是使种群(尤其是优势种或建群种)到具有生长、繁殖和适应进化变化的能力。要达到这个目标,种群遗传学知识必不可少。遗传变异是物种适应变化环境的基础,而局部适应则是种群适应局部环境遗传分化的结果,它们在生态恢复中起着重要的作用。分析了生态恢复过程中影响种群遗传变异因素,主要有取样误差和小种群效应(主要是瓶颈或建立者事件及其以后的近交和漂变等),在进行 相似文献
213.
控制以CO2为主的温室气体排放,“力争2030年前实现碳达峰,争取2060年前实现碳中和”是我国近年来面临的重大任务。碳排放研究是实现“双碳”目标的基础和前提,从碳排放测算、碳排放影响因素分析、行业碳排放研究三个方面对我国碳排放研究现状进行梳理,对近年来研究的重点方向、主要成果和目前存在的主要问题进行分析,并结合我国的“双碳”目标提出现阶段我国“以完善政策标准与加大政府扶持为基础,以产业结构调整与新兴产业发展、能源结构调整与新能源技术发展为核心,以探索CCUS(碳捕集、利用与封存)技术和增加碳汇及对居民低碳消费倾向的引导和培养为导向”的碳减排路径。 相似文献
214.
Bhattacharyya P Mitra A Chakrabarti K Chattopadhyay DJ Chakraborty A Kim K 《Environmental monitoring and assessment》2008,139(1-3):299-306
The present investigation deals with the limnobiotic status of Almatti reservoir from February, 2003 to January, 2005. The
study revealed that, the distribution and population density of zooplankton species depend upon the physico-chemical factors
of the environment. Statistical analysis showed that there exists a significant relation between the biological and non-biological
factors. The benthic fauna constituting the food of fish can be utilized for extensive culture operation so that the nutrients
in the reservoir are not only properly cycled but also serve as a check on further eutrophication. 相似文献
215.
216.
Relation of waste generation and composition to socio-economic factors: a case study 总被引:3,自引:0,他引:3
Bandara NJ Hettiaratchi JP Wirasinghe SC Pilapiiya S 《Environmental monitoring and assessment》2007,135(1-3):31-39
To develop an effective waste management strategy for a given region, it is important to know the amount of waste generated
and the composition of the waste stream. Past research has shown that the amount of waste generated is proportional to the
population and the average mean living standards or the average income of the people. In addition, other factors may affect
the amount and composition of waste. These are climate, living habits, level of education, religious and cultural beliefs,
and social and public attitudes. This paper presents the findings of a study carried out in a suburban municipal area in Sri
Lanka to determine the solid waste generation rate and waste composition based on field surveys and to determine the related
socio-economic factors. A database was developed that included information on the quantity and composition of waste generated
in a sample of households in the study area over a time period. The collected data was analysed to relate waste generation
and composition data to various socio-economic factors. Over 400 sample households were selected for the study using a stratified
random sampling methodology based on municipal wards and property values. A technique that considers both the number of households
in a particular income group (property value range) and the standard deviation of property values within a given income group
was used to determine the appropriate sample size for each municipal ward. Through category and regression analyses, the quantities
of waste and waste composition were related to several socio-economic factors. The paper describes the basis for the sample
selection, the methodology adopted for data collection, the socio-economic parameters used for the analysis, and the relationships
developed from the analysis. 相似文献
217.
218.
Kelly A. Loringer Author Vitae Author Vitae 《Journal of Safety Research》2008,39(5):509-517
Problem
Between 1992 and 2005, 1412 workers on farms died from tractor overturns. A Rollover Protective Structure (ROPS) is a proven intervention to reduce overturn deaths. However, farm characteristics that are associated with the adoption of ROPS are not well understood.Methods
ROPS prevalence statistics were derived from National Institute for Occupational Safety and Health (NIOSH) surveys that tracked ROPS use on farms. Data were from the years 1993, 2001, and 2004.Results
In 1993, 38% of tractors were equipped with ROPS. This increased to 51% by 2004. ROPS prevalence rates were higher on farms in the Southern region of the United States, on farms where the operator was 25-34 years old, and on farms with $100,000 or more of farm sales. Low ROPS prevalence rates were associated with farm operators 65 years old or older and with farms with less than $10,000 of farm product sales.Summary
The increase in ROPS prevalence between 1993 and 2004 has not been sufficient to decrease the rate of tractor overturn deaths on farms. Incentive programs targeting older farm operators and low-income farm operations are suggested to increase ROPS use on tractors.Impact on Industry
The study provides farm characteristics associated with low ROPS prevalence rates. The results can be used to target farms for future ROPS promotion activities. 相似文献219.
针对湘西洛塔岩溶区特殊的地质环境所造成的干旱缺水、水土流失、生态环境恶化等问题的特点,在调查、分析洛塔自然条件与水土资源、生态环境基本条件的基础上,实施了13处岩溶水资源开发利用示范工程。通过系统总结洛塔地区岩溶水资源合理开发利用技术与方法及岩溶水资源开发利用成功经验,提出了以岩溶水小流域为单元对岩溶水资源进行综合开发利用的5种模式:①地下河堵洞引水开发利用模式;②地下河出口及岩溶大泉引水开发利用模式;③凿引水隧洞拦截地下河开发利用模式;④地表地下联合水库开发利用模式;⑤表层岩溶泉开发利用模式。通过对失败工程的案例分析,认为在岩溶水资源开发利用过程中,应查清工程的岩溶发育规律及工程地质条件,分析经济技术支持的可行性,然后采取相适应的开采方式与方法。岩溶水资源进行综合开发利用的5种模式的提出,为在湘西实施“水源〖DK1〗·土地〖DK1〗·生态”持续发展战略,发展生态经济,实现脱贫致富,促进社会经济、生态环境良性循环,提供了切实可行的实用技术与方法借鉴。 相似文献
220.