全文获取类型
收费全文 | 359篇 |
免费 | 20篇 |
国内免费 | 52篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 2篇 |
环保管理 | 115篇 |
综合类 | 126篇 |
基础理论 | 115篇 |
污染及防治 | 25篇 |
评价与监测 | 16篇 |
社会与环境 | 20篇 |
灾害及防治 | 5篇 |
出版年
2024年 | 3篇 |
2023年 | 9篇 |
2022年 | 6篇 |
2021年 | 7篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 7篇 |
2014年 | 14篇 |
2013年 | 33篇 |
2012年 | 13篇 |
2011年 | 19篇 |
2010年 | 6篇 |
2009年 | 19篇 |
2008年 | 13篇 |
2007年 | 17篇 |
2006年 | 32篇 |
2005年 | 20篇 |
2004年 | 19篇 |
2003年 | 20篇 |
2002年 | 7篇 |
2001年 | 26篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 8篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1986年 | 1篇 |
1983年 | 1篇 |
排序方式: 共有431条查询结果,搜索用时 15 毫秒
301.
Use of Empirically Derived Source-Destination Models to Map Regional Conservation Corridors 总被引:4,自引:0,他引:4
SAMUEL A. CUSHMAN† KEVIN S. McKELVEY † MICHAEL K. SCHWARTZ† 《Conservation biology》2009,23(2):368-376
Abstract: The ability of populations to be connected across large landscapes via dispersal is critical to long-term viability for many species. One means to mitigate population isolation is the protection of movement corridors among habitat patches. Nevertheless, the utility of small, narrow, linear features as habitat corridors has been hotly debated. Here, we argue that analysis of movement across continuously resistant landscapes allows a shift to a broader consideration of how landscape patterns influence connectivity at scales relevant to conservation. We further argue that this change in scale and definition of the connectivity problem improves one's ability to find solutions and may help resolve long-standing disputes regarding scale and definition of movement corridors and their importance to population connectivity. We used a new method that combines empirically derived landscape-resistance maps and least-cost path analysis between multiple source and destination locations to assess habitat isolation and identify corridors and barriers to organism movement. Specifically, we used a genetically based landscape resistance model for American black bears ( Ursus americanus ) to identify major movement corridors and barriers to population connectivity between Yellowstone National Park and the Canadian border. Even though western Montana and northern Idaho contain abundant public lands and the largest wilderness areas in the contiguous United States, moving from the Canadian border to Yellowstone Park along those paths indicated by modeled gene flow required bears to cross at least 6 potential barriers. Our methods are generic and can be applied to virtually any species for which reliable maps of landscape resistance can be developed. 相似文献
302.
We develop a biologically correct cost system for production systems facing invasive pests that allows the estimation of population dynamics without a priori knowledge of their true values. We apply that model to a data set for olive producers in Crete and derive from it predictions about the underlying population dynamics. Those dynamics are compared to information on population dynamics obtained from pest sampling with extremely favorable results. 相似文献
303.
304.
Daniela Rabbie 《Journal of Agricultural and Environmental Ethics》2000,13(3-4):219-227
The influence of religious beliefs on people's attitudes andactions in the area of animal welfare was examined by interviewing dairyworkers on kibbutzim (communal agricultural settlements) in Israel.Workers on religiously observant kibbutzim were no more consistent intheir attitudes toward and treatment of dairy cows than workers onnon-observant and selectively observant kibbutzim. 相似文献
305.
Kristy M. Ferraro Anthony L. Ferraro A. Z. Andis Arietta Nathalie R. Sommer 《Conservation biology》2023,37(4):e14101
Conservation science is a morally motivated field, with implicit and explicit values built into its practice. As such, conservationists must engage with conservation ethics to interrogate underlying values. We examine cutting-edge ecological science and contemporary ethics to revisit two conservation norms that have become dogmatic in the field: ecological collectives, but not individual animals, are valuable and anthropomorphism should be staunchly avoided. Emerging studies demonstrate that individuals and their intraspecific variation can be instrumentally valuable for conservation science, and there is an emerging consensus within environmental philosophy around the moral worth of individuals. Thus, we suggest conservation science should explicitly recognize the value of individuals. We also argue that avoiding anthropomorphism is detrimental to conservation because critical anthropomorphism enables a more nuanced scientific approach—allowing conservationists to ask enlightened questions with creativity and compassion. We provide evidence that both dogmatic norms are scientifically and morally outdated and propose new normative values to push conservation towards more robust science and ethical practice. 相似文献
306.
Centner TJ 《Environmental management》2006,37(6):745-752
As point sources of pollution in the United States, concentrated animal feeding operations (CAFOs) are subject to the National
Pollution Discharge Elimination System permitting system requirements. Changes to federal regulations in 2003 and a 2005 court
decision have increased the governmental oversight of CAFOs. Manure application to fields from “large CAFOs” that results
in unpermitted discharges can be regulated under the Clean Water Act. The U.S. Environmental Protection Agency’s interpretation
of agricultural stormwater discharges was approved so that unpermitted discharges may arise if an owner or operator of a CAFO
fails to apply manure correctly. Owners and operators do not, however, have a duty to secure governmental permits in the absence
of a discharge. Turning to the federal provisions regarding nutrient management plans, a court found that they were deficient.
Moreover, the federal government needs to reconsider requirements that would reduce pathogens from entering surface waters.
Although these developments should assist in reducing the impairment of U.S. waters, concern still exists. Greater oversight
of nutrient management plans and enhanced enforcement efforts offer opportunities to provide greater assurance that CAFO owners
and operators will not allow a discharge of pollutants to enter surface waters. 相似文献
307.
猪场废弃物强制通风静态仓堆肥系统的试验研究 总被引:1,自引:0,他引:1
通过组织5个猪场废弃物堆肥试验,度量温度、表观性状、体积、重量损失、全氮、全磷、大肠杆菌值、蛔虫卵杀灭率和发芽指数等指标,检验了开发的强制通风静态仓堆肥系统的性能.结果表明,除起始含水率为80%试验堆体因起始含水率过高导致发生厌氧反应外,其余4个堆体均实现堆肥无害化、减量化、稳定化和资源化的处理目标;堆肥温度维持50℃以上5~7 d,或55℃以上3 d是大肠杆菌值达到国家粪便无害化卫生标准的必要条件;堆肥过程能有效脱除堆料的生物毒性,后腐熟阶段是必需阶段;氮、磷、钾等主要营养元素在堆肥前后呈现"浓缩效应".因此,堆肥化能提高猪场废弃物肥效和利用价值. 相似文献
308.
1980~1992年对大伙房水库6个站进行了不同季节底栖动物群落特征生态调查。共发现26种底栖动物,隶属于20属,3科。底栖动物密度由1980年的3335个/m2减少到1992年的829个/m2。共发现9种耐污种类,占总数的34.6%,密度占86.5%以上。水质生物学评价结果表明:1、2站动物种类少(10种),多样性指数低(1.2956),属α──中污染;5站动物种类多(16种),多样性指数高(1.4024),属β──中污染;大伙房水库只受到轻度污染。 相似文献
309.
310.
Occurrence and distribution of pharmaceuticals in wastewater from households, livestock farms, hospitals and pharmaceutical manufactures 总被引:3,自引:0,他引:3
Twenty-four pharmaceuticals were measured in wastewater from 12 municipal wastewater treatment plants (M-WWTPs), four livestock WWTPs (L-WWTPs), four hospital WWTPs (H-WWTPs) and four pharmaceutical manufacture WWTPs (P-WWTPs). The total concentration of pharmaceuticals in the influent samples was highest in the L-WWTPs followed by the P-WWTPs, H-WWTPs and M-WWTPs. The effluents had different patterns of pharmaceuticals than their corresponding influents because of the different fate of each compound in the WWTPs. Non-steroidal anti-inflammatory drugs (NSAIDs) were the most dominant in the influents from the M-WWTPs and P-WWTPs, while antibiotics were dominantly detected in the L-WWTP. In the H-WWTP influents, NSAIDs, caffeine and carbamazepine were dominant. In the P-WWTPs, the distribution of pharmaceuticals in the effluents varied with sampling sites and periods. The M-WWTP influents had the highest daily loads, while the effluents showed somewhat similar levels in all source types. 相似文献