全文获取类型
收费全文 | 19017篇 |
免费 | 172篇 |
国内免费 | 163篇 |
专业分类
安全科学 | 448篇 |
废物处理 | 776篇 |
环保管理 | 2202篇 |
综合类 | 3420篇 |
基础理论 | 5047篇 |
环境理论 | 7篇 |
污染及防治 | 4784篇 |
评价与监测 | 1300篇 |
社会与环境 | 1267篇 |
灾害及防治 | 101篇 |
出版年
2022年 | 159篇 |
2021年 | 158篇 |
2020年 | 124篇 |
2019年 | 139篇 |
2018年 | 248篇 |
2017年 | 281篇 |
2016年 | 402篇 |
2015年 | 305篇 |
2014年 | 546篇 |
2013年 | 1482篇 |
2012年 | 599篇 |
2011年 | 847篇 |
2010年 | 709篇 |
2009年 | 725篇 |
2008年 | 802篇 |
2007年 | 850篇 |
2006年 | 712篇 |
2005年 | 614篇 |
2004年 | 617篇 |
2003年 | 618篇 |
2002年 | 582篇 |
2001年 | 750篇 |
2000年 | 555篇 |
1999年 | 310篇 |
1998年 | 203篇 |
1997年 | 238篇 |
1996年 | 229篇 |
1995年 | 280篇 |
1994年 | 261篇 |
1993年 | 213篇 |
1992年 | 228篇 |
1991年 | 214篇 |
1990年 | 245篇 |
1989年 | 221篇 |
1988年 | 178篇 |
1987年 | 188篇 |
1986年 | 174篇 |
1985年 | 183篇 |
1984年 | 170篇 |
1983年 | 174篇 |
1982年 | 148篇 |
1981年 | 158篇 |
1980年 | 142篇 |
1979年 | 153篇 |
1978年 | 121篇 |
1977年 | 132篇 |
1976年 | 101篇 |
1975年 | 107篇 |
1973年 | 113篇 |
1972年 | 108篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
151.
152.
E. S. Zakharov V. M. Safronov L. P. Koryakina N. N. Smetanin 《Russian Journal of Ecology》2016,47(4):392-398
The population of foxes in the central regions of Yakutia has grown by a factor of four to five during the period from 2000 to 2011–2012, following an increase in the abundance of voles from the genus Microtus. A total of 130 carcasses of foxes taken in 2007–2012 have been examined. Age- and sex-related variation in morphological features has been described. The demographic structure of the population has been studied by estimating animal age from annual layers in the recording structures. Changes in female fertility and involvement in reproduction depending on age and feeding conditions have been analyzed. Changes in the composition of fox diet caused by long-term population depression in the mountain hare and their effect on the dynamics of fox abundance have been revealed. Age- and sex-related characteristics of the condition factor in foxes and sex-related differences in their dietary preferences have been demonstrated. 相似文献
153.
N. P. Korablev M. P. Korablev P. N. Korablev I. L. Tumanov 《Russian Journal of Ecology》2016,47(3):289-295
A comparative analysis of epigenetic variation has been performed in nine European populations and population groups of the American mink. It has been shown that differentiation of samples in nonmetric characters is due mainly to endogenous processes that have occurred in introduced populations in the course of colonization of new territory by the invasive species. Environmental factors have played a secondary role, with the influence of the geographic (latitudinal) origin of a given sample being considerable and stronger than that of macroclimatic factors. 相似文献
154.
V. G. Tereshchenko D. S. Khrystenko G. O. Kotovska L. I. Tereshchenko 《Russian Journal of Ecology》2016,47(4):364-370
The probable source of stone moroko, Pseudorasbora parva (Temminck & Schlegel, 1846), populations in lake- and stream-type Dnieper reservoirs was revealed. The dynamics and specific growth rates of these populations over 20 years were analyzed. The dynamic phase portrait method was used to determine the timing of stages in the process of invader naturalization and the periods when its populations were in equilibrium. The potential growth rates of P. parva populations in the Kremenchug and Dneprodzerzhinsk reservoirs were estimated. 相似文献
155.
156.
Polybrominated diphenyl ethers (PBDEs) in leachates from selected landfill sites in South Africa 总被引:2,自引:0,他引:2
The last few decades have seen dramatic growth in the scale of production and the use of polybrominated diphenyl ethers (PBDEs) as flame retardants. Consequently, PBDEs such as BDE -28, -47, -66, -71, -75, -77, -85, -99, -100, -119, -138, -153, -154, and -183 have been detected in various environmental matrices. Generally, in South Africa, once the products containing these chemicals have outlived their usefulness, they are discarded into landfill sites. Consequently, the levels of PBDEs in leachates from landfill sites may give an indication of the general exposure and use of these compounds. The present study was aimed at determining the occurrence and concentrations of most common PBDEs in leachates from selected landfill sites. The extraction capacities of the solvents were also tested. Spiked landfill leachate samples were used for the recovery tests. Separation and determination of the PBDE congeners were carried out with a gas chromatograph equipped with Ni63 electron capture detector. The mean percentage recoveries ranged from 63% to 108% (n=3) for landfill leachate samples with petroleum ether giving the highest percentage extraction. The mean concentrations of PBDEs obtained ranged from ND to 2670pgl(-1), ND to 6638pgl(-1), ND to 7230pgl(-1), 41 to 4009pgl(-1), 90 to 9793pgl(-1) for the Garankuwa, Hatherly, Kwaggarsrand, Soshanguve and Temba landfill sites, respectively. Also BDE -28, -47, -71 and BDE-77 were detected in the leachate samples from all the landfill sites; and all the congeners were detected in two of the oldest landfill sites. The peak concentrations were recorded for BDE-47 at three sites and BDE-71 and BDE-75 at two sites. The highest concentration, 9793+/-1.5pgl(-1), was obtained for the Temba landfill site with the highest BOD value. This may suggest some influence of organics on the level of PBDEs. Considering the leaching characteristics of brominated flame retardants, there is a high possibility that with time these compounds may infiltrate into the groundwater around the sites since most of the sites are not adequately lined. 相似文献
157.
Importance Measures (IMs) are used to rank the contributions of components or basic events to the system performance, e.g. its reliability or risk. Most times, IMs are calculated without due account of the uncertainties in the model of the behavior of the system. The objective of this work is to investigate how uncertainties can influence IMs and to develop a method for giving them due account in the corresponding ranking of the components or basic events. The uncertainties considered in this work affect the model parameters values and are assumed to be described by probability density functions. The method for ranking the contributors to the system performance measure is applied to the auxiliary feedwater system of a nuclear pressurized water reactor. 相似文献
158.
In The Netherlands, construction and demolition (C&D) waste is already to a large extent being reused, especially the stony fraction, which is crushed and reused as a road base material. In order to increase the percentage of reuse of the total C&D waste flow to even higher levels, a new concept has been developed. In this concept, called 'Closed Cycle Construction', the processed materials are being reused at a higher quality level and the quantity of waste that has to be disposed of is minimised. For concrete and masonry, the new concept implies that the material cycle will be completely closed, and the original constituents (clay bricks, gravel, sand, cement stone) are recovered in thermal processes. The mixed C&D waste streams are separated and decontaminated. For this purpose several dry separation techniques are being developed. The quality of the stony fraction is improved so much, that this fraction can be reused as an aggregate in concrete. The new concept has several benefits from a sustainability point of view, namely less energy consumption, less carbon dioxide emission, less waste production and less land use (for excavation and disposal sites). One of the most remarkable benefits of the new concept is that the thermal process steps are fuelled with the combustible fraction of the C&D waste itself. Economically the new process is more or less comparable with the current way of processing C&D waste. On the basis of the positive results of a feasibility study, currently a pilot and demonstration project is being carried out. The aim is to optimise the different process steps of the Closed Cycle Construction process on a laboratory scale, and then to verify them on a large scale. The results of the project are promising, so far. 相似文献
159.
Ramalina maciformis and Ramalina lacera were exposed to different solutions and UV-B to seek for alterations in the PSII photosynthetic quantum yield (F(v)/F(m)), in response to chemicals and radiation. For R. maciformis, significant alterations of the F(v)/F(m) ratio occurred only in response to different bisulphite solutions. The F(v)/F(m) ratio decreased most in R. maciformis and R. lacera following exposure to 5 and 1 mM bisulphite, respectively. Significant differences in F(v)/F(m) ratios were observed for R. lacera in response to different solutions and light at different wavelengths, this being synergistic. The PSII system was unaffected by simulated acid rain in both lichens. R. maciformis, in particular, may survive limited acid rain exposure owing to high Ca oxalate accumulation. The F(v)/F(m) ratio decreased most in R. lacera following short-term exposures to CuSO(4), suggesting that this species is more sensitive to Cu ions under acidic conditions. 相似文献
160.
Participatory environmental governance in China: public hearings on urban water tariff setting 总被引:1,自引:0,他引:1
In the late 1990s China started to expand its market economic reform to the public sector, such as water services. This reform led to major changes in urban water management, including water tariff management. The reforms in water tariff management relate not only to tariffs, but also to the decision-making on tariffs. Water tariff decision-making seems to move away from China's conventional mode of highly centralized and bureaucratic policy- and decision-making. The legalization, institutionalization and performance of public hearings in water tariff management forms a crucial innovation in this respect. This article analyzes the emergence, development and current functioning of public hearings in water tariff setting, and assesses to what extent public hearings are part of a turning point in China's tradition of centralized bureaucratic decision-making, towards more transparent, decentralized and participative governance. 相似文献