全文获取类型
收费全文 | 1290篇 |
免费 | 19篇 |
国内免费 | 193篇 |
专业分类
安全科学 | 50篇 |
废物处理 | 78篇 |
环保管理 | 110篇 |
综合类 | 345篇 |
基础理论 | 292篇 |
污染及防治 | 445篇 |
评价与监测 | 87篇 |
社会与环境 | 73篇 |
灾害及防治 | 22篇 |
出版年
2024年 | 1篇 |
2023年 | 10篇 |
2022年 | 55篇 |
2021年 | 18篇 |
2020年 | 21篇 |
2019年 | 23篇 |
2018年 | 83篇 |
2017年 | 32篇 |
2016年 | 59篇 |
2015年 | 65篇 |
2014年 | 59篇 |
2013年 | 79篇 |
2012年 | 50篇 |
2011年 | 84篇 |
2010年 | 61篇 |
2009年 | 67篇 |
2008年 | 82篇 |
2007年 | 96篇 |
2006年 | 71篇 |
2005年 | 38篇 |
2004年 | 79篇 |
2003年 | 54篇 |
2002年 | 50篇 |
2001年 | 105篇 |
2000年 | 47篇 |
1999年 | 26篇 |
1998年 | 10篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 11篇 |
1994年 | 8篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1964年 | 1篇 |
1960年 | 1篇 |
1951年 | 1篇 |
排序方式: 共有1502条查询结果,搜索用时 703 毫秒
881.
This paper investigates the relationship between pupils' environmental perception (in terms of preservation and utilisation of nature) and personality (in terms of risk-taking). 713 secondary school pupils in Switzerland were investigated. Environmental perception was assessed via three factors: Preservation, Utilisation of Nature and Consideration for Conservation. Risk-taking was evaluated via six factors: Positive Risking, Ambivalence, Thrill in Gambling, Ineffective Control, Effective Control, and Anger Reaction. Analysis of the correlation matrix between Risk-taking and Environmental perception revealed three profiles (types): the high scorer on Preservation is the controlled and cautious gambler. The Utiliser (anthropocentric) profile is essentially a mirror image of the first: the Utiliser does not enjoy unpredictable risks, reacts with anger when risks fail and has little control over his/her own risk-taking behaviour. The Consideration for Conservation (ecocentric) profile assumes a position between these two profiles. 相似文献
882.
Xiaodan Xue Yan You Jianhui Wu Bin Han Zhipeng Bai Naijun Tang Liwen Zhang 《环境科学学报(英文版)》2014,26(2):448-457
To investigate the levels of exposure to particulate-bound polycyclic aromatic hydrocarbon(PAH) and to estimate the risk these levels pose to traffic assistants(TAs) in Tianjin(a megacity in North China), a measurement campaign(33 all-day exposure samples, 25 occupational-exposure samples and 10 indoor samples) was conducted to characterize the TAs' exposure to PAHs, assess the cancer risk and identify the potential sources of exposure. The average total exposure concentration of 14 PAHs was approximately 2871 ± 928 ng/m3(on-duty), and 1622 ± 457 ng/m3(all-day). The indoor PAHs level was 1257 ± 107 ng/m3. After 8000 Monte Carlo simulations, the cancer risk resulting from exposure to PAHs was found to be approximately 1.05 × 10-4. A multivariate analysis was applied to identify the potential sources, and the results showed that, in addition to vehicle exhaust, coal combustion and cooking fumes were also another two important contributors to personal PAH exposure. The diagnostic ratios of PAH compounds agree with the source apportionment results derived from principal component analysis. 相似文献
883.
磷钨酸光催化六氟苯脱氟的研究 总被引:1,自引:1,他引:1
选择六氟苯作为目标化合物,利用266 nm脉冲激光照射磷钨酸与六氟苯的混合溶液证实了光催化转化六氟苯的可行性.结果表明,氟离子生成率与光照时间、pH值、磷钨酸初始投加量和添加物的量有关.氟离子生成率随激光脉冲次数的增加而升高.在溶液pH=1.0的条件下,氟离子生成率最高.2.0×10-4mol/L的六氟苯与5.0×10-6mol/L的磷钨酸的混合溶液在接受脉冲激光后,氟离子生成率可达208.1%.外加的氧化剂O2、KMnO4、K2S2O8可以有效氧化还原态的磷钨酸,实现整个光催化循环.溶液中存在的醇类及芳香族有机化合物不利于磷钨酸光催化转化六氟苯. 相似文献
884.
885.
886.
土地开发生态适宜度分析是区域土地利用规划的重要基础,本研究利用GIS技术,以营口某经济区为研究对象,将土地利用生态适宜度评价应用到开发区规划的环境影响评价中,在现状调查的基础上,利用了开发区生态适宜度评价指标体系的不同因子开展了评价,并借助GIS技术将数值计算和图形叠置有机结合,为开发区的合理规划提供决策依据。 相似文献
887.
888.
Greenhouse gas emissions during cattle feedlot manure composting 总被引:11,自引:0,他引:11
The emission of greenhouse gases (GHG) during feedlot manure composting reduces the agronomic value of the final compost and increases the greenhouse effect. A study was conducted to determine whether GHG emissions are affected by composting method. Feedlot cattle manure was composted with two aeration methods--passive (no turning) and active (turned six times). Carbon lost in the forms of CO2 and CH4 was 73.8 and 6.3 kg C Mg-1 manure for the passive aeration treatment and 168.0 and 8.1 kg C Mg-1 manure for the active treatment. The N loss in the form of N2O was 0.11 and 0.19 kg N Mg-1 manure for the passive and active treatments. Fuel consumption to turn and maintain the windrow added a further 4.4 kg C Mg-1 manure for the active aeration treatment. Since CH4 and N2O are 21 and 310 times more harmful than CO2 in their global warming effect, the total GHG emission expressed as CO2-C equivalent was 240.2 and 401.4 kg C Mg-1 manure for passive and active aeration. The lower emission associated with the passive treatment was mainly due to the incomplete decomposition of manure and a lower gas diffusion rate. In addition, turning affected N transformation and transport in the window profile, which contributed to higher N2O emissions for the active aeration treatment. Gas diffusion is an important factor controlling GHG emissions. Higher GHG concentrations in compost windrows do not necessarily mean higher production or emission rates. 相似文献
889.
890.