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   388篇
  免费   7篇
  国内免费   4篇
安全科学   17篇
废物处理   16篇
环保管理   70篇
综合类   22篇
基础理论   102篇
污染及防治   106篇
评价与监测   47篇
社会与环境   19篇
  2022年   2篇
  2021年   8篇
  2020年   3篇
  2019年   5篇
  2018年   9篇
  2017年   14篇
  2016年   11篇
  2015年   5篇
  2014年   18篇
  2013年   32篇
  2012年   22篇
  2011年   16篇
  2010年   15篇
  2009年   17篇
  2008年   29篇
  2007年   14篇
  2006年   22篇
  2005年   16篇
  2004年   12篇
  2003年   6篇
  2002年   22篇
  2001年   8篇
  2000年   16篇
  1999年   10篇
  1998年   3篇
  1997年   3篇
  1996年   4篇
  1995年   4篇
  1994年   5篇
  1993年   6篇
  1992年   2篇
  1991年   5篇
  1990年   2篇
  1986年   3篇
  1983年   1篇
  1982年   4篇
  1981年   2篇
  1979年   3篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
  1974年   2篇
  1973年   1篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
  1965年   2篇
排序方式: 共有399条查询结果,搜索用时 15 毫秒
1.
Environment, Development and Sustainability - Our society faces mounting pressure regarding the necessity of green consumption as issues related to the environment will likely become a severe...  相似文献   
2.

Landslide poses severe threats to the natural landscape of the Lesser Himalayas and the lives and economy of the communities residing in that mountainous topography. This study aims to investigate whether the landscape change has any impact on landslide occurrences in the Kalsi-Chakrata road corridor by detailed investigation through correlation of the landslide susceptibility zones and the landscape change, and finally to demarcate the hotspot villages where influence of landscape on landslide occurrence may be more in future. The rational of this work is to delineate the areas with higher landslide susceptibility using the ensemble model of GIS-based multi-criteria decision making through fuzzy landslide numerical risk factor model along the Kalsi-Chakrata road corridor of Uttarakhand where no previous detailed investigation was carried out applying any contemporary statistical techniques. The approach includes the correlation of the landslide conditioning factors in the study area with the changes in land use and land cover (LULC) over the past decade to understand whether frequent landslides have any link with the physical and hydro-meteorological or, infrastructure, and socioeconomic activities. It was performed through LULC change detection and landslide susceptibility mapping (LSM), and spatial overlay analysis to establish statistical correlation between the said parameters. The LULC change detection was performed using the object-oriented classification of satellite images acquired in 2010 and 2019. The inventory of the past landslides was formed by visual interpretation of high-resolution satellite images supported by an intensive field survey of each landslide area. To assess the landslide susceptibility zones for 2010 and 2019 scenarios, the geo-environmental or conditioning factors such as slope, rainfall, lithology, normalized differential vegetation index (NDVI), proximity to road and land use and land cover (LULC) were considered, and the fuzzy LNRF technique was applied. The results indicated that the LULC in the study area was primarily transformed from forest cover and sparse vegetation to open areas and arable land, which is increased by 6.7% in a decade. The increase in built-up areas and agricultural land by 2.3% indicates increasing human interference that is continuously transforming the natural landscape. The landslide susceptibility map of 2019 shows that about 25% of the total area falls under high and very high susceptibility classes. The result shows that 80% of the high landslide susceptible class is contained by LULC classes of open areas, scrubland, and sparse vegetation, which point out the profound impact of landscape change that aggravate landslide occurrence in that area. The result acclaims that specific LULC classes, such as open areas, barren-rocky lands, are more prone to landslides in this Lesser Himalayan road corridor, and the LULC-LSM correlation can be instrumental for landslide probability assessment concerning the changing landscape. The fuzzy LNRF model applied has 89.6% prediction accuracy at 95% confidence level which is highly satisfactory. The present study of the connection of LULC change with the landslide probability and identification of the most fragile landscape at the village level has been instrumental in delineation of landslide susceptible areas, and such studies may help the decision-makers adopt appropriate mitigation measures in those villages where the landscape changes have mainly resulted in increased landslide occurrences and formulate strategic plans to promote ecologically sustainable development of the mountainous communities in India's Lesser Himalayas.

  相似文献   
3.
Biochar derived from partial combustion of vegetation is ubiquitous and potentially effective in sequestration of environmental contaminants.Biochars were prepared by burning of red gum(Eucalyptus spp.) woodchips at 450 and 850°C(labeled as BC450 and BC850).These two biochars were found to possess markedly different properties in terms of surface area and porosity.Short-term equilibration tests(24 hr) were conducted to assess the sorption-desorption behavior of pyrimethanil in the soil amended with various amounts of biochar of each type,with a special focus on the desorption behavior of the sorbed pesticide through four times successive desorption by dilution.Sorption coefficient and isotherm nonlinearity of the amended soils progressively increased with the content of biochar in the soil.Biochar BC850 with higher surface area and microporosity showed a stronger effect on the reversibility of sorption pesticide.The soils amended with 5% BC450 and 1% BC850 had nearly the same sorption capacity for pyrimethanil;however,their desorption processes were very different with 13.65% and 1.49% of the sorbed pesticide being released,respectively.This study suggested that biochar in soil could be an important factor for immobilization of a pesticide and thus affecting its environment fate in soil.  相似文献   
4.
Making index insurance attractive to farmers   总被引:1,自引:0,他引:1  
There are several factors that influence whether people will want to participate in index insurance programs. A number of these influence their attractiveness on economic grounds, including both the size and timing of the premium and potential payouts, and the degree of risk aversion of the potential customers. Other factors make programs attractive for reasons that are not economic, but no less valid. These have to do with the trust that people have in the insurance product and the organizations involved in selling and managing it. Indeed, data from India, Africa, and South America show that these factors may be more important than the economic ones in influencing demand. Index insurance pilot projects, in order to estimate demand for alternative products, have typically involved a great deal of interaction with potential customers. It is important to recognize that such interaction is crucial not just as a research tool, but also as a means to build understanding and trust in the products. When scaling up from isolated pilots to operational programs, it is vital to recognize this trust building function by replicating participation efforts in every community. In this paper, we examine the role of field games in establishing and building trust in three important aspects of these projects for participants: trust in the insurance product, trust in the participating organizations, and trust in their own ability to make good decisions. While games have previously been used as a way to gauge interest in the product and to identify design features, we argue that these games are also valuable tools for constructing these kinds of trust.  相似文献   
5.
Environment, Development and Sustainability - COVID-19 has affected the global economy like no other crisis in the history of mankind. It forced worldwide lockdown and economic shutdown to the...  相似文献   
6.
7.
Conservation policy sits at the nexus of natural science and politics. On the one hand, conservation scientists strive to maintain scientific credibility by emphasizing that their research findings are the result of disinterested observations of reality. On the other hand, conservation scientists are committed to conservation even if they do not advocate a particular policy. The professional conservation literature offers guidance on negotiating the relationship between scientific objectivity and political advocacy without damaging conservation science's credibility. The value of this guidance, however, may be restricted by limited recognition of credibility's multidimensionality and emergent nature: it emerges through perceptions of expertise, goodwill, and trustworthiness. We used content analysis of the literature to determine how credibility is framed in conservation science as it relates to apparent contradictions between science and advocacy. Credibility typically was framed as a static entity lacking dimensionality. Authors identified expertise or trustworthiness as important, but rarely mentioned goodwill. They usually did not identify expertise, goodwill, or trustworthiness as dimensions of credibility or recognize interactions among these 3 dimensions of credibility. This oversimplification may limit the ability of conservation scientists to contribute to biodiversity conservation. Accounting for the emergent quality and multidimensionality of credibility should enable conservation scientists to advance biodiversity conservation more effectively.  相似文献   
8.
9.
East African cichlids display extensive variation in sex determination systems. The species Astatotilapia calliptera is one of the few cichlids that reside both in Lake Malawi and in surrounding waterways. A. calliptera is of interest in evolutionary studies as a putative immediate outgroup species for the Lake Malawi species flock and possibly as a prototype ancestor-like species for the radiation. Here, we use linkage mapping to test association of sex in A. calliptera with loci that have been previously associated with genetic sex determination in East African cichlid species. We identify a male heterogametic XY system segregating at linkage group (LG) 7 in an A. calliptera line that originated from Lake Malawi, at a locus previously shown to act as an XY sex determination system in multiple species of Lake Malawi cichlids. Significant association of genetic markers and sex produce a broad genetic interval of approximately 26 megabases (Mb) using the Nile tilapia genome to orient markers; however, we note that the marker with the strongest association with sex is near a gene that acts as a master sex determiner in other fish species. We demonstrate that alleles of the marker are perfectly associated with sex in Metriaclima mbenjii, a species from the rock-dwelling clade of Lake Malawi. While we do not rule out the possibility of other sex determination loci in A. calliptera, this study provides a foundation for fine mapping of the cichlid sex determination gene on LG7 and evolutionary context regarding the origin and persistence of the LG7 XY across diverse, rapidly evolving lineages.  相似文献   
10.
Abstract

To determine covariates of radon testing behavior, we surveyed by mail a random sample of all Boston University employees (N = 915) six to nine months after they had been informed of the availability of radon testing services through the University's medical center. The response rate was 58%. Analysis suggests blue collar workers were underrepresented within the response rate. Slightly more than half of the respondents (51%) were men. The majority (69%) were under the age of 45. Twenty-seven percent of the respondents (N = 143) had tested their homes for radon. Bivariate analysis revealed important differences between radon testers and nontesters. Testers were 12 times more likely to be home owners than renters (p = 0.00), and were more knowledgeable about radon's characteristics and testing procedures (p = 0.00). Testers were more likely to view radon as a serious problem (p = 0.00), to consider radon testing efficacious (p = 0.00), and to consider themselves susceptible to exposure (p = 0.00). Testers were also less likely to perceive barriers to radon testing. We used logistic regression to compare the usefulness of the Health Belief Model and the Diffusion of Innovations Model in predicting radon testing. We concluded that the knowledge deficits and barriers to radon testing identified in this study should be targeted in radon educational interventions.  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