全文获取类型
收费全文 | 245篇 |
免费 | 5篇 |
国内免费 | 16篇 |
专业分类
安全科学 | 36篇 |
废物处理 | 7篇 |
环保管理 | 52篇 |
综合类 | 119篇 |
基础理论 | 14篇 |
污染及防治 | 11篇 |
评价与监测 | 16篇 |
社会与环境 | 10篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 6篇 |
2015年 | 10篇 |
2014年 | 17篇 |
2013年 | 20篇 |
2012年 | 6篇 |
2011年 | 25篇 |
2010年 | 16篇 |
2009年 | 12篇 |
2008年 | 12篇 |
2007年 | 17篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 3篇 |
2000年 | 9篇 |
1999年 | 13篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1988年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有266条查询结果,搜索用时 31 毫秒
81.
Iodine-131 concentrations in tap water higher than 100 Bq L−1 were reported by several local governments in Japan following the Fukushima Daiichi Nuclear Power Plant accident. Some individuals in the emergency-response community recommended the boiling of tap water to remove iodine-131. However, the tap water boiling tests in this study showed no iodine-131 loss from the tap water with either short-term boiling (1-10 min) or prolonged boiling (up to 30 min) resulting in up to 3-fold volume reductions. In this situation, boiling was shown to be not effective in removing iodine-131 from tap water; indeed even higher concentrations may result from the liquid-volume reduction accompanying this process. 相似文献
82.
乌江干流梯级电站生态调度现状分析 总被引:2,自引:0,他引:2
乌江是我国十三大水电基地之一,主要的开发任务为发电,其次为航运,兼顾防洪及其他。本研究在乌江干流上选取了4个具有代表性的断面,运用修正的Tennant法和综合法计算了维持乌江干流各代表性河段基本健康所需的生态需水量。研究表明,目前乌江干流梯级电站采取的调度措施能够满足各代表性河段所需的最小生态需水量。但目前的调度措施仍是建立在发电效益最大化基础上的,未能从干流生态环境系统的特殊要求进行调度,给干流生态环境造成了一定影响。本文最后提出了从多方面开展乌江干流梯级电站生态调度研究工作的建议。 相似文献
83.
The paper puts focus on the selection of an appropriate framework for benchmarking studies of power cycles with CO2 capture. The need for a reference power plant without CO2 capture in a benchmarking study is emphasized. The impact of the use of site-specific plant boundary conditions is discussed as well as the selection of computational assumptions to reflect future technology development. A significant part of the paper is dedicated to a study of how changes in the benchmarking framework to reflect technology development can give additional knowledge about the potential for different CO2 capture technologies. A major conclusion, based on the findings, is that it should be highly relevant for technology providers to investigate the future development potential for a CO2 capture technology before launching a product development program. 相似文献
84.
In the recent years concerns whether exposure to electromagnetic fields (EMF) from base station antennae can cause adverse
health effects are grown. Great attention is paid on risk of EMF exposure to people living in a close proximity of base stations.
In this issue, a point of interest is the personnel mounting, adjusting and maintaining base stations. Their working tasks
require stay in high EMF levels’ conditions. There are only few studies concerning this specific occupational group. The results
from our previous investigation (COST 281—Graz, 2006) show that in many cases on performing some specific tasks operators
are overexposed according to our national legislation, and ICNIRP guidelines. Here, we present an extended study covering
more base stations and more precise scenario for performed tasks and working positions. Results of exposure assessment are
presented. They include energetic load calculations on the basis of Bulgarian national legislation, and the corresponding
SAR values. Data are used to determine permissible time duration for each particular work operation and served as a base for
limiting the exposure and proposal for protective measures for the personnel. 相似文献
85.
Urban Environmental Management in Botswana: Toward a Theoretical Explanation ofPublic Policy Failure
ELISHA N. TOTENG 《Environmental management》2001,28(1):19-30
For the last three and half decades, Botswana has been widely acclaimed to be one of sub-Saharan Africa's longest and most
stable liberal democracies, coupled with and sustained by a growing economy. One of the major contradictions, however, within
this development scenario, has been the neglect of environmental problems in the country in general, and urban environmental
issues in particular.
Part of the problem fueling the misconception of environmental issues in Botswana is the state's domination of the country's
environmental agenda. This is linked to the power disjunction in decision-making and policy processes between state and nonstate
actors over the most appropriate course of action to tackle the problems. Without adopting appropriate analytical frameworks,
it is possible that the problem of urban environmental mismanagement in Botswana will persist. This article examines some
of the major urban environmental issues in Botswana from neighborhood, citywide, and urban–rural interface perspectives. Further,
the elite theory of public policy is used to explain constraints on policy change in the urban environmental management arena
in Botswana. 相似文献
86.
87.
介绍了新版排污许可证的主要特点和对油品销售企业全面覆盖的实现方式,阐明油品销售企业排污许可证申报类型和依据,从6个方面介绍了油库、加油站取得排污许可证后遇到的相关问题并列举部分例证,分析问题产生的根本原因,提出改进建议。 相似文献
88.
采用油指纹多元统计方法,对嘉兴市杭州塘和长山河水系沿岸加油站9个不同来源的轻质柴油进行了分类鉴别,并考察了风化的影响.结果表明:仅基于GC-MS谱图,很难对不同轻质柴油的来源进行鉴别;但基于GC-MS谱图,提取正构烷烃及多环芳烃特征比值,进一步采用多元统计方法,可以对不同来源的轻质柴油进行区分.考虑实际水环境中油污染物会风化,向河水中投入两种轻质柴油,考察了不同初始浓度和不同风化时间下的油指纹变化,发现油污染物初始浓度为0.5 mg·L~(-1)时,所有特征比值在风化过程中均极不稳定,无法用于分类鉴别;油污染物初始浓度达到1.0 mg·L~(-1)及以上时,特征比值C_(17)/Pr、C_(18)/Ph在风化5 d内可用作油指纹的鉴别指标,5 d后无法用于鉴别;特征比值Pr/Ph、(C_(19)+C_(20))/(C_(21)+C_(22))、CPI受风化时间影响小,始终可以作为油指纹鉴别的特征指标. 相似文献
89.
公众对手机基站电磁辐射投诉典型问题及解答 总被引:2,自引:0,他引:2
随着中国的移动通信网络进入3G时代,手机基站建设掀起了新一轮高潮.手机基站是手机用户之间信息传递的枢纽,而信息传输的承载方式就是电磁波,也就是通常所称的"电磁辐射".由于绝大多数公众对电磁辐射并不了解,因此"谈辐色变",对手机基站的电磁辐射投诉量逐年增加,一定程度上影响了社区和谐与移动通信业的顺利推进.本文将比较有代表... 相似文献
90.
In this paper, the power output of the cycle is taken as objective for performance optimization of an irreversible regenerated closed Brayton cycle coupled to constant-temperature thermal energy reservoirs in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM). The analytical formulae about the relations between power output and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers and the regenerator, the irreversible compression and expansion losses in the compressor and turbine, and the pressure drop loss in the piping. The maximum power output optimization is performed by searching the optimum heat conductance distribution corresponding to the optimum power output among the hot- and cold-side heat exchangers and the regenerator for the fixed total heat exchanger inventory. The influence of some design parameters, including the temperature ratio of the heat reservoirs, the total heat exchanger inventory, the efficiencies of the compressor and the turbine, and the pressure recovery coefficient, on the optimum heat conductance distribution and the maximum power output are provided. The power plant design with optimization leads to smaller size including the compressor, turbine, and the hot- and cold-side heat exchangers and the regenerator. 相似文献