全文获取类型
收费全文 | 5863篇 |
免费 | 66篇 |
国内免费 | 258篇 |
专业分类
安全科学 | 158篇 |
废物处理 | 300篇 |
环保管理 | 414篇 |
综合类 | 1163篇 |
基础理论 | 1414篇 |
环境理论 | 5篇 |
污染及防治 | 1942篇 |
评价与监测 | 433篇 |
社会与环境 | 312篇 |
灾害及防治 | 46篇 |
出版年
2023年 | 66篇 |
2022年 | 159篇 |
2021年 | 171篇 |
2020年 | 87篇 |
2019年 | 99篇 |
2018年 | 206篇 |
2017年 | 229篇 |
2016年 | 293篇 |
2015年 | 231篇 |
2014年 | 328篇 |
2013年 | 480篇 |
2012年 | 348篇 |
2011年 | 401篇 |
2010年 | 267篇 |
2009年 | 220篇 |
2008年 | 356篇 |
2007年 | 337篇 |
2006年 | 274篇 |
2005年 | 215篇 |
2004年 | 189篇 |
2003年 | 170篇 |
2002年 | 140篇 |
2001年 | 96篇 |
2000年 | 63篇 |
1999年 | 75篇 |
1998年 | 43篇 |
1997年 | 38篇 |
1996年 | 37篇 |
1995年 | 41篇 |
1994年 | 39篇 |
1993年 | 19篇 |
1992年 | 30篇 |
1991年 | 28篇 |
1990年 | 27篇 |
1989年 | 19篇 |
1988年 | 16篇 |
1987年 | 12篇 |
1986年 | 27篇 |
1985年 | 13篇 |
1984年 | 12篇 |
1983年 | 13篇 |
1982年 | 21篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1972年 | 9篇 |
1966年 | 16篇 |
1965年 | 10篇 |
1957年 | 9篇 |
1956年 | 11篇 |
1954年 | 9篇 |
排序方式: 共有6187条查询结果,搜索用时 15 毫秒
81.
Catherine Potvin Petra Tschakert Frédéric Lebel Kate Kirby Hector Barrios Judith Bocariza Jaime Caisamo Leonel Caisamo Charianito Cansari Juan Casamá Maribel Casamá Laura Chamorra Nesar Dumasa Shira Goldenberg Villalaz Guainora Patrick Hayes Tim Moore Johana Ruíz 《Mitigation and Adaptation Strategies for Global Change》2007,12(8):1341-1362
This paper is part of a two-year study to investigate the feasibility of initiating a Clean Development Mechanism (CDM) project
in an indigenous community of Eastern Panamá, Ipetí-Emberá. We use participatory mapping and matrices as well as household
surveys to develop a land-use/land-cover baseline scenario and examine the role of local participation in assessing land-use
change. In Ipetí, land-use change has not occurred in a linear way over the last decades, and our data unveils socio-economic
factors as potential key drivers of change. The concordance that we observed between geographic information and individual
and collective perceptions of land-use change substantiates the possibility of using local knowledge in the establishment
of baseline data for CDM projects. Our calculations suggest that the total carbon (C) stocks in the Tierra Colectiva (TC) of Ipetí-Emberá in 2004 represents a 47% reduction from the estimated C stock at the onset of settlement in the early
1970’s. Results from the participatory assessments predict that, in 2024 and in absence of a CDM project, the C stocks will
decline from 301,859 t C in 2004 to 155,730 t C, which constitutes a reduction of 52%. The scenario with CDM estimates C stocks
of 305,853 t C for 2024, a value slightly superior to the 2004 value. In the TC there is ground to believe that cattle ranching
is likely to become an ever more important activity as the population is young and growing and cannot easily move elsewhere.
Forests tend to be cleared for cultivation while pastures are established on short fallows. Our baseline scenario underlines
the potential for a CDM project to make a significant difference in the future C stocks of this landscape. 相似文献
82.
Muir DC Koczanski K Rosenberg B Béland P 《Environmental pollution (Barking, Essex : 1987)》1996,93(2):235-245
Blubber samples from 16 dead beluga whales (Delphinapterus leucas) collected during 1993-1994 in the St Lawrence River estuary were analysed for PCB congeners and other persistent organochlorines (DDT-group, chlorinated bornanes (toxaphene, CHB), chlordane SigmaCHL), hexachloro-cyclohexanes (SigmaHCH), chlorobenzenes (SigmaCBz), tris(p-chlorophenyl methane (TPMe) and mirex). Concentrations and relative proportions of major individual organochlorine components were within the same range as previous results for this population. Temporal trends were studied by combining the results with data from the analysis of 44 samples (1986-1990) and (for DDT and Aroclor PCBs only) with 20 samples (1982-1985) reported by Martineau et al., 1987. Results were lipid normalized and then age-adjusted by an ANCOVA model. Significant relationships between age and concentrations of most organochlorine groups were found for females but not for males. Significant declines were observed in SigmaDDT, and Aroclor PCBs (1.5- and 1.9-fold, respectively) in males between the 1982-1985 and 1993-1994 collection periods. Significant declines were also observed for SigmaHCH and SigmaCBz in males between 1986-1988 and 1993-1994. Mean concentrations of CHBs were significantly higher in 1993-1994 than in earlier years while dieldrin, SigmaCHL, mirex, and TPMe showed no trend. Declines in concentrations of major organochlorine groups were not observed in females possibly because of higher year to year, and within year, variation. The temporal trend in DDT and PCB concentrations in male beluga blubber paralleled trends in seals, eels, and seabirds in the St Lawrence estuary observed during the 1980s. 相似文献
83.
为了探讨玻璃纤维过滤器处理含DEP雾废气的效率问题,在实验室进行了DEP雾去除实验。考查了不同气体入口浓度、过滤流速下玻璃纤维过滤捕集装置对含DEP雾废气的净化能力,结果表明:利用玻璃纤维过滤器去除DEP雾,在DEP雾粒径主要分布为0.48~3.4μm之间,DEP雾浓度小于220 mg/m3,过滤流速小于10 cm/s情况下,玻璃纤维过滤器对DEP雾的去除率大于99%,最大气体流量下的压力降小于1610Pa;同时对含油(酸)雾废气除雾效果好,特别是对于粒径特别细微的油(酸)雾,捕集效率也很高,还可回收利用,不会产生二次污染。 相似文献
84.
85.
现代电化学技术与环境保护 总被引:2,自引:0,他引:2
介绍了电化学技术在清洁工艺的开发、清洁产品的制备、废水与废气的处理、被污染土壤的修复和环境污染物监测方面的应用情况。电化学技术具有能量利用率高、经济实用以及污染物产生量少或污染物去除率高等特点,在环境保护领域具有广阔的应用前景。 相似文献
86.
侯祺棕 《中国安全科学学报》1996,6(3):1-5
矿山呼吸性粉尘危害程度评价法研究侯祺棕(武汉工业大学资源与环境工程系)[摘要]通过对矿山呼吸性粉尘实际危害程度评价法的研究,并经实例检验,推荐两种具有可操作性和足够准确的评价法,这对矿山呼吸性粉尘监测新技术的推广具有重要意义。[关键词]呼吸性粉尘,危... 相似文献
87.
企业人力资源需求预测是人力资源管理的一项重要工作,它可以帮助企业明确未来人力需求趋势,做好人才储备工作;同时也可以帮助企业合理预测未来各部门、各类职位人员的需求情况,做好企业的定岗定编工作.面对日益复杂、变化更加剧烈的内外部环境,如何对动态环境中企业人力资源需求做出科学预测?本文介绍的目标规划法是预测企业在动态环境中的人力资源需求数量的一个实用性工具. 相似文献
88.
89.
Simple models for phosphorus loss from manure during rainfall 总被引:1,自引:0,他引:1
Mechanistic, predictive equations for phosphorus (P) transport in runoff from manure-applied fields constitute a critical knowledge gap for developing nonpoint-source pollution models. We derived two simple equations to describe the P release from animal manure during a rainfall event-one based on first-order P desorption kinetics and one based on second-order kinetics. The manure characteristics needed in the two kinetic equations are the maximum amount of water-extractable phosphorus (WEP) and a characteristic desorption time. Water-extractable P can be measured directly but currently the characteristic time can only be obtained by fitting experimental data. In addition, we evaluated two models usually used to estimate P loss from soil, the Elovitch equation and power function, both of which relate P loss to time. The models were tested against previously published data of P release from different manures under laboratory conditions. All equations fit the data well. Of the two kinetic equations, the second-order model showed better agreement with the data than the first-order model; for example, maximum relative differences between the model results and measured data were 2.6 and 4.7%, respectively. The characteristic times varied between 20 min for dairy manure and almost 100 min for poultry manure. The characteristic time did not appear to change with flow rate but decreased with smaller manure aggregates. The parameters for power-function relationships could not be related to measured manure characteristics. These results provide the first step to process-based approximations for predicting P release from manure with time during rainfall shortly after land application, when P losses are the greatest. 相似文献
90.
阐明了金属涂料生产中挥发性有机物(VOC)的危害性,介绍了一种工程造价低,处理效果较好的治理方法,供投资生产金属涂料的生产者参考。 相似文献