首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1314篇
  免费   150篇
  国内免费   398篇
安全科学   133篇
废物处理   88篇
环保管理   252篇
综合类   880篇
基础理论   142篇
环境理论   5篇
污染及防治   177篇
评价与监测   30篇
社会与环境   154篇
灾害及防治   1篇
  2024年   5篇
  2023年   22篇
  2022年   42篇
  2021年   53篇
  2020年   72篇
  2019年   54篇
  2018年   54篇
  2017年   73篇
  2016年   95篇
  2015年   98篇
  2014年   91篇
  2013年   136篇
  2012年   144篇
  2011年   153篇
  2010年   92篇
  2009年   88篇
  2008年   64篇
  2007年   88篇
  2006年   94篇
  2005年   59篇
  2004年   54篇
  2003年   40篇
  2002年   38篇
  2001年   32篇
  2000年   27篇
  1999年   25篇
  1998年   8篇
  1997年   10篇
  1996年   7篇
  1995年   8篇
  1994年   8篇
  1993年   7篇
  1992年   3篇
  1991年   1篇
  1990年   2篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1984年   1篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1978年   1篇
  1972年   1篇
  1971年   1篇
排序方式: 共有1862条查询结果,搜索用时 15 毫秒
1.
This paper examines long-run and short-run dynamics of renewable energy consumption on carbon dioxide (CO2) emissions and economic growth in the European Union. This study employs cointegration tests, Granger causality tests and vector error correction estimates to examine the direction of Granger causality, the long-run dynamics of economic growth and energy variables on carbon emissions. This study analyses time series data from the World Development Indicators over the period from1961 to 2012. The results of this study support a link between renewable energy consumption, economic growth, industrialization, exports and CO2 emissions in the long-run and short-run. The results support that the sign of the long-run dynamics from the endogenous variables to the CO2 emissions variable is negative and significant, which implies that the energy and environmental policies of the European Union aimed at curbing CO2 emissions must have been effective in the long-term. Furthermore, renewable energy consumption and exports have significant negative impact on CO2 emissions in the short-run. However, industrialization and economic growth have positive impact on CO2 emissions in the short-run. The results suggest that both economic growth and industrialization must have been achieved at the cost of harming the environment. The finding suggests that the increasing consumption of renewable energy tends to play an important role in curbing carbon emissions in the region.  相似文献   
2.
李楠  王鹏  宋伦  邵泽伟  赵海勃 《化工环保》2018,38(3):300-304
以颗粒活性炭(GAC)为载体、铜为活性组分、铈为助剂组分、草酸钠为沉淀剂,采用浸渍焙烧法制得CuO_x-CeO_2/GAC催化剂。以H_2O_2为氧化剂,微波强化催化湿式过氧化氢氧化(CWPO)处理二甲亚砜(DMSO)初始质量浓度为1 000 mg/L的废水,处理3 min后DMSO去除率达93.8%。催化剂第7次使用时DMSO去除率仍保持在75%以上。初始废水pH在3~9范围内,DMSO去除率均在85%以上。助剂Ce的加入提高了催化剂表面活性组分的分散性和稳定性,使催化剂的活性稳定性和使用寿命显著提高。  相似文献   
3.
ABSTRACT

The calculation of the combined uncertainty of the international estimated short-term intake (IESTI) of ethephon residues in apples is shown as an example. The ethephon residues in apples were reported by the Joint FAO (Food and Agriculture Organization of the United Nations)/WHO (World Health Organization) Meeting on Pesticide Residues (JMPR). The apple consumption data were taken from the IESTI (international short-term intake) calculation template used by the JMPR. The IESTI was calculated with the currently used method (case 2a) and a proposed one recommended by the EFSA (European Food Safety Authority)/RIVM (Dutch National Institute for Public Health) Scientific Workshop co-sponsored by FAO and WHO. In this example, the ratio of IESTIproposed/IESTIcurrent and their combined relative uncertainty are about 2.8, and 1.7, respectively. The larger IESTI and uncertainty obtained with the proposed equation are the consequence of calculation only with the large portion (LP) instead of its combination with unit mass, and the MRL instead of the highest residue (HR). The LP is the major contributor to the combined uncertainty. Both the calculated IESTI and its combined uncertainty depend on the actual food – pesticide residue combination, and should be calculated for each case.  相似文献   
4.
The materiality of digital communication inflicts substantial environmental damage: the extraction of resources needed to produce digital devices; the toxicity of e-waste; and the rapidly increasing energy demands required to sustain data generated by digital communication. This damage, however, is paradoxically under-theorized in scholarship on environmental sustainability. Despite the existing critique of the “techno-fix” approach in sustainability studies, digitization – and digital communication in particular – continue to be celebrated as the tool for environmental sustainability; an approach we coin “digital solutionism.” The article presents the first systematic review of the literature to map the implicit assumptions about the relationships between digital communications and environmental sustainability, in order to examine how digital solutionism manifests, and why it persists. We propose a concept matrix that identifies the key blind spots with regards to environmental damages of the digital, and call for a paradigmatic shift in environmental sustainability studies. An agenda for future research is put forward that advocates for the following: (1) a systematic account of material damages of devices, platforms and data systems adopted into sustainability research and practice, resulting in changes in both research framing and methodological foundations; (2) a reconceptualization and denaturalization of the digital itself as a promising solution; (3) a theoretical dialogue between sustainability studies and environmental communication. (4) an expansion of environmental communication as a field, from focusing on the communication aspect of environmental change to include the environmental footprint of communication itself.  相似文献   
5.
为了测定煤层硫化氢(H2S)含量,防治矿井H2S涌出,提出一种通过钻屑法测定煤层H2S含量的方法。在未受采动影响的新鲜煤壁,采用钻屑法取样,通过测定煤样H2S解吸量、取样过程损失量和H2S残存量确定煤层H2S含量。根据溶于水中H2S的p H值和色谱分析解吸气体中H2S体积分数,确定H2S解吸量;根据煤样解吸规律和气样H2S体积分数,确定H2S损失量;根据色谱分析残存气体中H2S体积分数,确定其残存量。用此方法,对山西某矿H2S涌出煤层进行现场和实验室测定。研究表明,该矿H2S含量为(4.465~6.701)×10-3m3/t。钻屑法测定煤层H2S含量是可行的,可以为矿井H2S治理提供基础数据。  相似文献   
6.
Explosion indices and explosion behaviour of Al dust/H2/air mixtures were studied using standard 20 l sphere. The study was motivated by an explosion hazard occurring at some accidental scenarios considered now in ITER design (International Thermonuclear Experimental Reactor). During Loss-of-Vacuum or Loss-of-Coolant Accidents (LOCA/LOVA) it is possible to form inside the ITER vacuum vessel an explosible atmosphere containing fine Be or W dusts and hydrogen. To approach the Be/H2 explosion problem, Be dust is substituted in this study by aluminium, because of high toxicity of Be dusts. The tested dust concentrations were 100, 200, 400, 800, and 1200 g/m3; hydrogen concentrations varied from 8 to 20 vol. % with 2% step. The mixtures were ignited by a weak electric spark. Pressure evolutions were recorded during the mixture explosions. In addition, the gaseous compositions of the combustion products were measured by a quadruple mass-spectrometer. The dust was involved in the explosion process at all hydrogen and dust concentrations even at the combination ‘8%/100 g/m3’. In all the other tests the explosion overpressures and the pressure rise rates were noticeably higher than those relevant to pure H2/air mixtures and pure Al dust/air mixtures. At lower hybrid fuel concentrations the mixture exploded in two steps: first hydrogen explosion followed by a clearly separated Al dust explosion. With rising concentrations, the two-phase explosion regime transits to a single-phase regime where the two fuel components exploded together as a single fuel. In this regime both the hybrid explosion pressures and pressure rise rates are higher than either H2 or Al ones. The two fuels compete for the oxygen; the higher the dust concentration, the more part of O2 it consumes (and the more H2 remains in the combustion products). The test results are used to support DUST3D CFD code developed at KIT to model LOCA or LOVA scenarios in ITER.  相似文献   
7.
介绍了甘肃省的风力资源及风力发电的发展现状,重点阐述了白银地区、玉门地区、酒泉瓜州、金昌地区、敦煌地区和武威地区等几个具有代表性地区的风能资源优势及风电建设情况,指出了甘肃省风力发电在技术和政策等方面目前还存在的主要问题,分析了产生这些问题的原因,提出了促进甘肃省风力发电事业发展的对策。  相似文献   
8.
杨进  郦和生  王岽  王彬 《化工环保》2021,41(2):140-145
CaO2具有很好的稳定性,可在水和土壤中逐步分解生成H2O2成为氧化反应的氧化剂,已作为H2O2的替代物用于环保领域的研究中。介绍了CaO2的作用机理,综述了CaO2用于处理含卤代物、染料、抗生素、苯系物等废水的研究进展,以及CaO2用于治理含石油烃、多环芳烃、苯系物和农药的污染土壤的研究进展。提出未来的研究方向:充分利用CaO2水解生成O2和H2O2的特性,探索化学与生物联合修复技术;探究CaO2与其他氧化剂联用技术,从而增加CaO2修复技术的适用性和经济性。  相似文献   
9.
在研究影响我国CO 2排放因素领域,基于投入产出技术的分解模型已成为主要的分析工具,现有研究多分别基于消费视角或收益视角展开分析。为全面评估各行业收益与消费对其上游、下游行业碳排放的综合影响,整合基于收益与基于消费两个视角,运用2012年与2015年我国投入产出表,构建两层嵌套式结构分解分析模型(SDA),比较分析消费规模效应、收益规模效应、行业流入、流出增加值变动效应、增加值结构变动效应等14个影响各行业碳排放变动的关键因素,并借助对消费者原则碳排放估算公式的重构,更准确地实现从增加值视角对各行业消费者原则碳排放变动的关键影响因素分析。研究发现:①研究期内,我国在总产出增长29.14%的同时碳排放量上升1.46%,各行业碳排放强度下降是主要的减排因素,其中建筑业减排贡献最大。②增排效应方面,影响从大到小依次为消费规模、收益规模、完全投入结构与完全消费结构四项效应,且前两个规模效应的影响是后两个结构效应的2倍以上,尤其建筑业消费规模效应、煤炭采选产品业收益规模效应增排较大。③消费规模扩大导致增排的原因并非行业本身生产规模扩大,而主要在于建筑业、服务业等行业规模扩张时吸收其他行业流入的增加值量增多。④收益规模扩大导致的增排效应方面,细分来说从大到小依次为劳动者报酬、生产税净额、固定资产折旧、营业盈余四项效应,且行业差异显著,如煤炭采选产品业的劳动者报酬效应,石油、炼焦产品和核燃料加工品业的生产税净额效应以及电力、热力生产和供应业的营业盈余效应增排贡献较大,而煤炭采选产品业的营业盈余效应、批发、零售业和住宿、餐饮业的生产税净额效应则减排贡献较大。  相似文献   
10.
氢能具有储运便捷、来源多样、洁净环保等突出优点,许多国家把发展氢能作为重要的能源战略。氢安全是氢能大规模商业化应用的重要保障。在分析国内外氢安全领域近年来最新研究进展的基础上,依次从氢泄漏与扩散、氢燃烧与爆炸、氢与金属材料相容性及氢风险评价等方面,系统总结了国内外氢安全研究面临的挑战,并对我国氢安全的发展提出了建议。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号