全文获取类型
收费全文 | 102篇 |
免费 | 1篇 |
专业分类
安全科学 | 5篇 |
环保管理 | 13篇 |
综合类 | 21篇 |
基础理论 | 31篇 |
污染及防治 | 21篇 |
评价与监测 | 8篇 |
社会与环境 | 3篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 2篇 |
2014年 | 2篇 |
2013年 | 7篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 5篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1974年 | 1篇 |
1943年 | 1篇 |
1941年 | 1篇 |
排序方式: 共有103条查询结果,搜索用时 15 毫秒
11.
Per Schubert Nils G. A. Ekelund Thomas H. Beery Christine Wamsler K. Ingemar Jönsson Andreas Roth 《Journal of Environmental Policy & Planning》2018,20(3):298-312
While ecosystem-based planning approaches are increasingly promoted through international and national policies, municipalities are still struggling with translating them into practice. Against this background, this paper aims to increase the knowledge of current advances and possible ways to support the implementation of the ecosystem services (ES) approach at the municipal level. More specifically, we analyze how ES have been integrated into comprehensive planning within the municipality of Malmö in Sweden over the last 60 years, a declared forerunner in local environmental governance. Based on a content analysis of comprehensive plans over the period 1956–2014 and interviews with municipal stakeholders, this paper demonstrates how planning has shifted over time toward a more holistic view of ES and their significance for human well-being and urban sustainability. Both explicit and implicit applications of the ES concept were found in the analyzed comprehensive plans and associated programs and projects. Our study shows how these applications reflect international, national, and local policy changes, and indicates how municipalities can gradually integrate the ES approach into comprehensive planning and facilitate the transition from implicit to more explicit knowledge use. 相似文献
12.
13.
14.
Numerous cases of hereditary diseases and disorders have been reported in wild animals bred in captivity, but little attention has been paid to the particular genetic management problems that arise when such defects occur. These problems include the obstacle of eliminating the deleterious allele(s) without contemporary loss of genetic variability. In this paper we use the statistical methods of pedigree analysis to address questions regarding a previously presumed hereditary form of blindness observed in a captive wolf population bred for conservation purposes in Scandinavian zoos. The most likely mode of inheritance coincides with an autosomal recessive allele with either a full penetrance or a reduced penetrance of 0.6 (depending on the reliability of studbook records). Using these two models of inheritance, we calculate the probability of carrying the blindness allele for each living animal. Analysis of the effect of removing high-probability carriers on founder allele survival and level of inbreeding demonstrates that the frequency of the deleterious allele can be significantly reduced without seriously affecting founder allele survival or current degree of inbreeding in the wolf population. 相似文献
15.
This paper reviews the experience and status of coastal aquaculture of seaweeds, mollusks, fish and crustaceans in eastern Africa and the islands of the western Indian Ocean. In many respects, coastal aquaculture is still in its infancy in the region, and there is a pressing need to formulate development strategies aimed at improving the income and assuring the availability of affordable protein to coastal communities. This paper also draws from positive and negative experiences in other parts of the world. The requirements of feed and fry, and the conversion of mangroves are used to illustrate how some aquaculture activities constitute a net loss to global seafood production. The paper presents both general and specific sustainability guidelines based on the acknowledgement of aquaculture as an ecological process. It is concluded that without clear recognition of its dependence on natural ecosystems, the aquaculture industry is unlikely to develop to its full potential in the region. 相似文献
16.
17.
Nils Holtug 《Journal of Agricultural and Environmental Ethics》2001,14(2):168-178
It is suggested that the Harm Principle can be viewedas the moral basis on which genetically modified (GM) food iscurrently regulated. It is then argued (a) that the concept ofharm cannot be specified in such a manner as to render the HarmPrinciple a plausible political principle, so this principlecannot be used to justify existing regulation; and (b) that evenif the Harm Principle were a plausible political principle, itcould not be used alone in the regulation of GM food, since itdoes not express a concern for the expected benefits of suchfood. 相似文献
18.
Spatial anatomy of species survival: effects of predation and climate-driven environmental variability 总被引:1,自引:0,他引:1
Ciannelli L Dingsør GE Bogstad B Ottersen G Chan KS Gjøsaeter H Stiansen JE Stenseth NC 《Ecology》2007,88(3):635-646
The majority of survival analyses focus on temporal scales. Consequently, there is a limited understanding of how species survival varies over space and, ultimately, how spatial variability in the environment affects the temporal dynamics of species abundance. Using data from the Barents Sea, we study the spatiotemporal variability of the juvenile Atlantic cod (Gadus morhua) survival. We develop an index of spatial survival based on changes of juvenile cod distribution through their first winter of life (from age-0 to age-1) and study its variability in relation to biotic and abiotic factors. Over the 25 years analyzed (1980-2004), we found that, once the effect of passive drift due to dominant currents is accounted for, the area where age-0 cod survival was lowest coincided with the area of highest abundance of older cod. Within this critical region, the survival of age-0 cod was negatively affected by its own abundance, by that of older cod, and by bottom depth. Furthermore, during cold years, age-0 cod survival increased in the eastern and coldest portion of the examined area, which was typically avoided by older conspecifics. Based on these results we propose that within the examined area top-down mechanisms and predation-driven density dependence can strongly affect the spatial pattern of age-0 cod survival. Climate-related variables can also influence the spatial survival of age-0 cod by affecting their distribution and that of their predators. Results from these and similar studies, focusing on the spatial variability of survival rates, can be used to characterize species habitat quality of marine renewable resources. 相似文献
19.
Rolanda Lange Johanna Werminghausen Nils Anthes 《Behavioral ecology and sociobiology》2013,67(8):1239-1247
Copulation in the simultaneous hermaphrodite Siphopteron sp. involves injection of prostate fluids into the mating partner with a stylet-shaped penile appendage before insemination. It has been hypothesised that such traumatic secretion transfer manipulates sex roles or the recipient’s short-term reproductive output. To test manipulative effects of traumatic secretion transfer, we ablated the stylet of male-acting individuals and then paired them to untreated focal individuals. Mating behaviour and egg output of focal individuals was then compared between this ‘no injection group’ and a ‘control group’ with sham-treated mating partners. We found that penile stylets were inserted at different areas prior to and during insemination, but prostate fluid injection was restricted to the first phase. Here, injections were into the anterior foot region, indicating that prostate secretions target the nearby male or female copulatory tracts. Our experimental manipulation of traumatic secretion transfer did not affect the exhibited mating roles. Matings in both treatments were usually reciprocal so that both partners acted in the male as well as female mating role. Moreover, sperm recipient reproductive output did not differ between treatments. We conclude that traumatic secretion transfer in this species either affects currently unmeasured traits, for instance the donor’s paternity share, or that these sea slugs are so well-adapted to traumatic secretion transfer that the effects were too subtle to be detected in our current assays. 相似文献
20.
Supportive Breeding and Variance Effective Population Size 总被引:2,自引:0,他引:2
The practice of supporting weak, wild populations through release of individuals bred in captivity is becoming an increasingly important conservation measure. A frequently recommended form of such breeding-release activity refers to supportive breeding: a fraction of the target population is brought into captivity for reproduction, and the resulting progeny are released to mix with the wild segment of the population. We derived an expression for the variance effective size of a population managed through supportive breeding and discuss its relationship to previously published equations that are based on the assumption of random mating. We show that the effect of supportive breeding may be quite different on the inbreeding and the variance effective sizes. Whereas supportive breeding always results in a reduction of the inbreeding effective number, the variance effective number may either decrease, increase, or remain unchanged. We discuss these observations in relation to conservation management and suggest some general guidelines for supportive breeding situations. Our recommendations include making a distinction between inbreeding and variance effective numbers; taking particular care when dealing with organisms with high reproductive potential; assuring that the amount of drift be no larger than it would be without supportive breeding; and focusing primarily on the variance effective size of a population-that is, on the effective number directly related to the rate of loss of gene diversity. 相似文献