全文获取类型
收费全文 | 10885篇 |
免费 | 41篇 |
国内免费 | 16篇 |
专业分类
安全科学 | 74篇 |
废物处理 | 808篇 |
环保管理 | 1506篇 |
综合类 | 1063篇 |
基础理论 | 3478篇 |
环境理论 | 2篇 |
污染及防治 | 1933篇 |
评价与监测 | 1093篇 |
社会与环境 | 960篇 |
灾害及防治 | 25篇 |
出版年
2023年 | 11篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 24篇 |
2019年 | 26篇 |
2018年 | 1514篇 |
2017年 | 1403篇 |
2016年 | 1241篇 |
2015年 | 158篇 |
2014年 | 62篇 |
2013年 | 98篇 |
2012年 | 516篇 |
2011年 | 1417篇 |
2010年 | 736篇 |
2009年 | 653篇 |
2008年 | 944篇 |
2007年 | 1276篇 |
2006年 | 62篇 |
2005年 | 72篇 |
2004年 | 65篇 |
2003年 | 96篇 |
2002年 | 155篇 |
2001年 | 41篇 |
2000年 | 40篇 |
1999年 | 21篇 |
1998年 | 27篇 |
1997年 | 13篇 |
1996年 | 17篇 |
1995年 | 23篇 |
1994年 | 19篇 |
1993年 | 17篇 |
1992年 | 12篇 |
1991年 | 9篇 |
1990年 | 12篇 |
1989年 | 7篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 3篇 |
1985年 | 13篇 |
1984年 | 21篇 |
1983年 | 23篇 |
1982年 | 8篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 8篇 |
1977年 | 3篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 4篇 |
1935年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
81.
R.H. Brown 《Agriculture, ecosystems & environment》1985,12(4):371-388
Several genera and species of plant-parasitic nematodes cause losses in grain yield in cereals; some are of relatively minor importance (e.g. Anguina tritici (Steinbuch) Chitwood, the cause of “ear cockle” in wheat), while others such as the cereal cyst nematode (CCN) (Heterodera avenae Woll.) have a wide geographic distribution, infest extensive areas, and may cause losses valued at millions of dollars. Some of these nematodes are difficult to control because the measures that might be used are uneconomic to apply or are impractical. The control of CCN, however, can be achieved, and several successful strategies have been developed in parts of Europe and in Australia. The various measures available to Australian cereal growers include: crop rotation, resistant cultivars, manipulation of sowing dates, use of nematicides, and reduced cultivation. The selection of an appropriate management strategy for the control of CCN is influenced by factors such as: climate, cereal species grown, yield potential, rotations practised and the availability of alternative crops, pathotype present, farm size, availability of resistant cultivars, nematicides registered, and the availability of suitable equipment for their application. 相似文献
82.
中国的美国梦会变成世界的恶梦吗?对于中国13亿人口,美国梦正在变成中国梦。数百万的中国人已经过上美国式的生活:食用更多肉类,开私家车,出国旅游,像美国人那样把迅速增加的收入用于其他开销。尽管这些美国生活方式的消费者还只是中国人口的一小部分,但中国对世界资源的需求已经变得相当可观。 相似文献
83.
Bosch J 《Die Naturwissenschaften》2002,89(12):575-578
Female midwife toads (genus Alytes) emit highly variable reciprocal calls of unclear function prior to and during courtship. In some species, female-female competition, expressed as physical fighting, has been reported. Males of Majorcan midwife toads (Alytes muletensis) show phonotactic response to female calls, and females of Iberian midwife toads (Alytes cisternasii) respond differently according to the male call characteristics. In this study, I test the hypothesis of female-female acoustic competition as an additional function of female reciprocal calls. Playback tests indicate that female calls are not clearly involved in female acoustic competition in the Iberian midwife toad, therefore female calls could be directed at males rather than towards competitive females. 相似文献
84.
近来巴西大豆生产的增长引发了环境保护团体以及一些学者对于亚马孙盆地的热带自然环境正在向大豆种植地转换的关注.大豆生产的支持者则认为大豆是区域的一种可行性农产品;对于环境的关注是没有根据的,因为新的大豆种植地正在替代已经被砍伐的林地或者是转换了的土地.两种观点虽被提出却都没有对大豆生产扩充区的土地利用与土地覆被(LULC)状况进行过综合研究与估量.本案例研究是在巴西的朗多尼亚州,亚马孙盆地西南部的维列纳市(Vimena),通过遥感手段对1996~2001年以来该市大豆种植面积的大幅度增加所伴随的土地利用与土地覆被变化状况进行评估.结果表明虽然森林变成了大豆生产基地,但是大部分的大豆生产的增长归功于对已有土地的微量扩充、已伐林地的转换以及更高的单位产量. 相似文献
85.
Gamergates (i.e. mated reproductive workers) are mostly known from ant species within the Ponerinae. We report here the discovery of gamergates in two species of the subfamily Myrmicinae. Until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. However, in two species of the myrmicine Metapone (Metapone madagascarica and a newly discovered, not yet described Metapone species) all workers have six ovarioles and a spermatheca; and some of them are mated. There are no morphological differences between mated and non-mated workers. Field observations and laboratory studies indicate that colonies of the Metapone species can reproduce with gamergates only. 相似文献
86.
Although amphibians are highly vocal, they generally emit only a limited number of acoustic communication signals. We report here the extraordinarily rich vocal repertoire of Amolops tormotus, a ranid species in China. These frogs produce countless vocalizations, some of which share features of birdsong or primate calls, e.g., ultrasonic frequency components, multiple upward and downward FM sweeps, and sudden onset and offset of selective harmonic components within a call note. Frame-by-frame video analysis of the frog's calling behavior suggests the presence of two pairs of vocal sacs that may contribute to the remarkable call-note complexity in this species. Electronic supplementary material to this paper can be obtained by using the Springer LINK server located at http://dx.doi.org/10.1007/s00114-002-0335-x. 相似文献
87.
Aysen Müezzinoğlu Tolga Elbir Abdurrahman Bayram 《Environmental Engineering and Policy》1998,1(2):109-116
In this study, an inventory of air pollutant emission estimates from major air polluting sources in Turkey for period between 1985 and 2005 with 5-year intervals were estimated. Inventory covers anthropogenic sources of five major air pollutants of particulate matter, sulfur dioxide, carbon monoxide, nitrogen oxides and non-methane volatile organic compounds. Their break-down with respect to main activity sectors were shown and their distribution by the largest industrial source categories were worked out as annual estimates. This inventory and its analysis point to serious environmental implications of air pollutants and a need to develop a policy plan for reducing these emissions. 相似文献
88.
89.
Dr. O. W. Jones Nolan E. Penn Stephen Shuchter Claire A. Stafford Teri Richards Colleen Kernahan Jennifer Gutierrez Patricia Cherkin Sylvia Reinsch Barbara Dixson 《黑龙江环境通报》1984,4(4):249-256
This article reports the results of a retrospective study designed to examine the responses of couples to genetic amniocentesis and subsequent therapeutic abortions due to birth defects. Fourteen women and 12 men were interviewed by experienced interviewers using a structured format designed by the authors, and each interview was audiotaped for later rating. The 5 raters (all women) were instructed to independently rate each interview using forms designed by the authors to elicit information about many aspects of the participant's individual responses as well as perceptions of spouse's responses to the process of pregnancy, amniocentesis, therapeutic abortion, and sequelae. Ratings of all 5 raters were conjoined and an homogeneous narrative was constructed for each interview. Results indicate, in general, that the respondent couples coped well with this experience. In fact 70 per cent of the respondent couples described their marital relationships as becoming closer as a result of their experience. Only a few participants reported long-term deleterious effects. Most couples coped by relying on relatives, friends, and occasionally, professional counsellors. In addition, most participants in this study suggested ways to improve the medical and psychological aspects of this experience. 相似文献
90.
Independent teams undertook environmental monitoring of particular concentrations of major construction projects forming part of Hong Kong’s U.S. $20 billion airport infrastructure programme located in dense urban areas. The team combination of environmental specialists with experienced civil engineers enabled pragmatic mitigation measures to be developed and accepted by the construction personnel with the result that potentially significant adverse impacts were averted. The authors discuss the mechanism and success of this innovative approach. 相似文献