全文获取类型
收费全文 | 11669篇 |
免费 | 842篇 |
国内免费 | 1375篇 |
专业分类
安全科学 | 1846篇 |
废物处理 | 299篇 |
环保管理 | 1485篇 |
综合类 | 8019篇 |
基础理论 | 469篇 |
污染及防治 | 695篇 |
评价与监测 | 708篇 |
社会与环境 | 215篇 |
灾害及防治 | 150篇 |
出版年
2024年 | 61篇 |
2023年 | 204篇 |
2022年 | 256篇 |
2021年 | 370篇 |
2020年 | 370篇 |
2019年 | 371篇 |
2018年 | 257篇 |
2017年 | 283篇 |
2016年 | 416篇 |
2015年 | 504篇 |
2014年 | 959篇 |
2013年 | 587篇 |
2012年 | 703篇 |
2011年 | 737篇 |
2010年 | 554篇 |
2009年 | 526篇 |
2008年 | 591篇 |
2007年 | 716篇 |
2006年 | 586篇 |
2005年 | 525篇 |
2004年 | 420篇 |
2003年 | 566篇 |
2002年 | 429篇 |
2001年 | 393篇 |
2000年 | 329篇 |
1999年 | 330篇 |
1998年 | 302篇 |
1997年 | 265篇 |
1996年 | 263篇 |
1995年 | 228篇 |
1994年 | 191篇 |
1993年 | 155篇 |
1992年 | 116篇 |
1991年 | 112篇 |
1990年 | 115篇 |
1989年 | 92篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
在对兰州市主城区机动车保有量进行深入调查的基础上,就兰州市机动车尾气排放对大气环境的影响进行了分析和评估,并对汽车尾气排放污染物进行了对比;阐述了机动车尾气是造成兰州市城市大气污染的重要因素。同时,借鉴国内外先进的预防、控制和处理机动车尾气污染的方法,对机动车尾气排放污染控制措施进行了研究,提出了合理减缓、控制机动车尾气污染等措施。 相似文献
72.
73.
74.
水质分析化验是我国环境保护工作中非常重要的组成部分。水质分析化验数据准确性与科学管理实验室质量控制密不可分,因此质量控制在水质分析化验过程中具有非常重要的意义。本文就水质分析中影响质量控制的因素进行了分析,并且对质量控制的具体措施进行了阐述,希望对水质分析化验中的质量控制工作有一定的参考价值。 相似文献
75.
76.
本文主要介绍了城市隧道口废气排放对周边环境影响的问题,通过对城市隧道口废气排放问题的污染现状、研究方法、污染因子的选取、控制方案等方面进行分析与总结,得出现阶段主要研究结论及下一步研究内容,为城市隧道口交通废气的治理提供依据。 相似文献
77.
78.
79.
Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential 总被引:6,自引:0,他引:6
Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles (58.4 Gg). The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles. 相似文献
80.
Carbon dioxide(CO2) emissions are a leading contributor to the negative effects of global warming. Globally, research has focused on effective means of reducing and mitigating CO2 emissions. In this study, we examined the efficacy of eco-industrial parks(EIPs) and accelerated mineral carbonation techniques in reducing CO2 emissions in South Korea.First, we used Logarithmic Mean Divisia Index(LMDI) analysis to determine the trends in carbon production and mitigation at the existing EIPs. We found that, although CO2 was generated as byproducts and wastes of production at these EIPs, improved energy intensity effects occurred at all EIPs, and we strongly believe that EIPs are a strong alternative to traditional industrial complexes for reducing net carbon emissions. We also examined the optimal conditions for using accelerated mineral carbonation to dispose of hazardous fly ash produced through the incineration of municipal solid wastes at these EIPs. We determined that this technique most efficiently sequestered CO2 when micro-bubbling, low flow rate inlet gas, and ammonia additives were employed. 相似文献