全文获取类型
收费全文 | 1521篇 |
免费 | 8篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 49篇 |
废物处理 | 59篇 |
环保管理 | 141篇 |
综合类 | 256篇 |
基础理论 | 378篇 |
环境理论 | 2篇 |
污染及防治 | 468篇 |
评价与监测 | 98篇 |
社会与环境 | 76篇 |
灾害及防治 | 6篇 |
出版年
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 20篇 |
2020年 | 22篇 |
2019年 | 15篇 |
2018年 | 30篇 |
2017年 | 48篇 |
2016年 | 47篇 |
2015年 | 47篇 |
2014年 | 39篇 |
2013年 | 71篇 |
2012年 | 58篇 |
2011年 | 91篇 |
2010年 | 50篇 |
2009年 | 56篇 |
2008年 | 80篇 |
2007年 | 81篇 |
2006年 | 72篇 |
2005年 | 55篇 |
2004年 | 55篇 |
2003年 | 59篇 |
2002年 | 51篇 |
2001年 | 32篇 |
2000年 | 41篇 |
1999年 | 20篇 |
1998年 | 11篇 |
1997年 | 11篇 |
1996年 | 14篇 |
1995年 | 19篇 |
1994年 | 15篇 |
1993年 | 17篇 |
1992年 | 16篇 |
1991年 | 8篇 |
1990年 | 12篇 |
1989年 | 10篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 17篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 12篇 |
1979年 | 22篇 |
1978年 | 11篇 |
1977年 | 19篇 |
1976年 | 25篇 |
1975年 | 12篇 |
1937年 | 4篇 |
排序方式: 共有1533条查询结果,搜索用时 15 毫秒
201.
Jørn Cruickshank 《Journal of Environmental Policy & Planning》2018,20(3):313-327
In the Lister region in the southern part of Norway, attempts are currently being made to facilitate for a green shift. The paper discusses two different approaches towards such a challenge. The first is procedural, where success or failure hinges on the methods applied in the effort to convince locals to incorporate climate considerations. The alternative is to reflect upon how a green ideology blends into pre-existing ideological elements in the region. It is claimed that an important reason for the failure so far to place the environment at the core of regional development, is that too much emphasis has been put on the first approach, on procedure and dialogue, whereas few efforts have been made to understand the structure of the discursive terrain in the region. What prevents a green shift has less to do with methods and is more connected to the dominance of a logic of economic growth and the fact that locals are confident that nature is already dealt with in a sensible manner. The conclusion is that we need to understand what people are concerned about and what prevents them to change, before we start telling them how to think and do development. 相似文献
202.
203.
Mert Glm Murat Kadir Yesilyurt Atilla Bilgin 《Environmental science and pollution research international》2020,27(10):10351-10366
Among alternative fuels, biodiesel has been emphasized as a substantial candidate for diesel engines because of many advantages. However, the main shortcomings preventing more widespread use of biodiesel are high production cost and viscosity. In order to simultaneously overcome both of these shortcomings, the reaction conditions for the transesterification of waste cooking oil (WCO) were optimized using Taguchi and the full factorial design approaches. The analyses of signal to noise ratio and variance were also performed to identify the dominance of reaction conditions on viscosity and biodiesel yield. As a result, the optimal reaction conditions giving the lowest kinematic viscosity (3.991 cSt) and the highest biodiesel yield (98.19%) were determined to be as follows: sodium methoxide amount of 1.00 wt%, reaction time of 60 min, reaction temperature of 55 °C, and methanol to oil molar ratio of 6:1. The catalyst amount and methanol to oil molar ratio were found to be the most significant conditions influencing on the viscosity (10.36% and 78.87% contributions) and the yield (58.48% and 20.17% contributions), respectively. Finally, all physicochemical properties of final waste cooking oil biodiesel (WCOB) produced under optimal reaction conditions were found to meet the EN 14214. 相似文献
204.
205.
206.
207.
208.
Voluntary and active participation by a wide variety of actors is a prerequisite for successful societal transitions towards sustainability. The ‘Commitment to Sustainable Development 2050’ is a national-level initiative in Finland, aiming to mobilise a large-scale transition involving various societal actors through openly communicated commitments to concrete actions. Each commitment should focus on at least one of the eight nationally defined sustainability objectives connected to the global Sustainable Development Goals. This article assesses the implementation and the development needs of the commitment process based on a range of materials. The results highlight the importance of securing adequate resources for long-term coordination and continuous development of the commitment process, trust creation through long-term and open communication, and flexibility allowing for experimentation aimed at finding new modes of interaction between the public and private sectors. 相似文献
209.
Certainty of paternity covaries with paternal care in birds 总被引:5,自引:0,他引:5
Summary Male investment in parental care has been hypothesized to be affected or not to be affected by their certainty of paternity, depending on the particular assumptions of theoretical models. We used data on paternal care and extra-pair paternity from 52 bird species to determine whether male parental care was related to certainity of paternity. Paternal care was measured as the relative male contribution to nest building, courtship feeding, incubation, and feeding of nestlings, respectively. Males of avian taxa did not provide less parental care during nest building, courtship feeding and incubation if the frequency of extra-pair paternity was high. However, male participation in feeding of offspring was significantly negatively related to the frequency of extra-pair paternity. This was also the case when the effects of potentially confounding variables such as developmental mode of offspring (which may result in males being freed from parental duties), extent of polygyny (which may result in less paternal care), and the frequency of multiple clutches during one breeding season (which may increase the probability of finding fertile females during the nestling period) were controlled statistically. These results suggest that the extent of paternal care has been affected by certainty of paternity, and that sex roles during the energetically most expensive parts of reproduction have been shaped by sperm competition. 相似文献
210.
Adaptations of meadow pipits to parasitism by the common cuckoo 总被引:4,自引:0,他引:4
Summary The meadow pipit Anthus pratensis is one of the most frequent hosts in Europe parasitized by the common cuckoo Cuculus canorus. The cuckoo normally removes one or more of the host eggs and replaces them with one of its own. The aim of the present study, which was conducted in an upland area of Central Norway, was to test the following question: assuming the cuckoo has laid a mimetic egg (which is slightly larger than and slightly different in color from that of a meadow pipit egg), under what circumstances are the parent meadow pipits able to detect such parasitism? The reaction of the meadow pipits to artificial parasitism was tested. Plastic model cuckoo eggs were used that bore a striking resemblance to real cuckoo eggs found in other meadow pipit nests in the same area. In addition, in some experiments a stuffed cuckoo dummy was used. The meadow pipits tolerated the experimental procedures and remained in their nests when given an artificial cuckoo egg, with or without removal of one of the host's eggs. However, when a host egg was removed and replaced with an artificial cuckoo egg, and at the same time a stuffed cuckoo dummy was presente, 50% of the birds deserted their nests. The difference between this result and the results of the other experiments was statistically significant. When only the stuffed cuckoo was presented, without any egg manipulations, the meadow pipits reacted in the same way as in the egg experiments. We conclude that the meadow pipit is capable of detecting whether or not its nest has been parasitized, provided it has observed the cuckoo near the nest site. Furthermore, because of the results of our experiments, we reject the hypothesis that the cuckoo has evolved egg removal behavior in order to prevent the host from assessing an increase in egg numbers. 相似文献