全文获取类型
收费全文 | 430篇 |
免费 | 4篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 12篇 |
废物处理 | 13篇 |
环保管理 | 41篇 |
综合类 | 179篇 |
基础理论 | 85篇 |
污染及防治 | 72篇 |
评价与监测 | 17篇 |
社会与环境 | 15篇 |
灾害及防治 | 3篇 |
出版年
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 8篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 16篇 |
2014年 | 17篇 |
2013年 | 19篇 |
2012年 | 11篇 |
2011年 | 20篇 |
2010年 | 13篇 |
2009年 | 14篇 |
2008年 | 12篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 4篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2000年 | 7篇 |
1998年 | 6篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1991年 | 6篇 |
1990年 | 8篇 |
1989年 | 6篇 |
1985年 | 5篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 5篇 |
1970年 | 7篇 |
1965年 | 4篇 |
1964年 | 5篇 |
1962年 | 4篇 |
1961年 | 4篇 |
1960年 | 5篇 |
1959年 | 5篇 |
1957年 | 7篇 |
1956年 | 4篇 |
1955年 | 9篇 |
1954年 | 3篇 |
1952年 | 3篇 |
1934年 | 4篇 |
排序方式: 共有437条查询结果,搜索用时 31 毫秒
271.
Maria Neofytou Nathalie Brison Kris Van den Bogaert Luc Dehaspe Koen Devriendt Anja Geerts Joris R. Vermeesch 《黑龙江环境通报》2018,38(2):148-150
Noninvasive prenatal testing (NIPT) can very accurately determine fetal sex during pregnancy. We present an exceptional case where NIPT contradicts the ultrasound-based sex determination. The pregnant woman was recipient of a liver transplant from a male donor. Graft-derived cell-free DNA released into the maternal circulation clouded the NIPT-based sex determination. Hence, NIPT is not advisable when the pregnant mother underwent an organ transplant. 相似文献
272.
273.
T. D. Seeley Susanne Kühnholz Anja Weidenmüller 《Behavioral ecology and sociobiology》1996,39(6):419-427
If a forager bee returns to her hive laden with high-quality nectar but then experiences difficulty finding a receiver bee
to unload her, she will begin to produce a conspicuous communication signal called the tremble dance. The context in which
this signal is produced suggests that it serves to stimulate more bees to function as nectar receivers, but so far there is
no direct evidence of this effect. We now report an experiment which shows that more bees do begin to function as nectar receivers
when foragers produce tremble dances. When we stimulated the production of tremble dances in a colony and counted the number
of bees engaged in nectar reception before and after the period of intense tremble dancing, we found a dramatic increase.
In two trials, the number of nectar receivers rose from 17% of the colony’s population before tremble dancing to 30–50% of
the population after the dancing. We also investigated which bees become the additional nectar receivers, by looking at the
age composition of the receiver bees before and after the period of intense tremble dancing. We found that none of the bees
recruited to the task of nectar reception were old bees, most were middle-aged bees, and some were even young bees. It remains
unclear whether these auxiliary nectar receivers were previously inactive (as a reserve supply of labor) or were previously
active on other tasks. Overall, this study demonstrates that a honey bee colony is able to rapidly and strongly alter its
allocation of labor to adapt to environmental changes, and it further documents one of the communication mechanisms underlying
this ability.
Received: 31 May 1996/Accepted after revision: 9 August 1996 相似文献
274.
The costs of courtship and mating may include increased risks of predation, the transmission of pathogens, and a loss of foraging opportunities. Thus, a female's decision to tolerate a courting male will depend upon how these costs offset the benefits of mating, which will depend on her reproductive and nutritional status. While these costs may be similar for mated and unmated females, the benefits of mating will be less for mated than virgin females. However, the cost of lost foraging opportunities may be higher for females with fewer nutritional reserves necessary for forming eggs. We examined how these costs and benefits influence the courtship and mating behaviour of male and female orb-web spiders, Argiope keyserlingi. In the field, females on webs that also contained a courting male intercepted fewer prey items per hour than females on webs without a male. In the laboratory, the presence of a courting male at the hub also attracted mantid predators to the web, increasing the risk of predation for both male and female. Staged mating experiments in the laboratory revealed that the frequency of female attacks and pre-copulatory cannibalism was greater among mated than virgin females. Feeding history did not affect aggression in virgin females but, among mated females, food-deprived spiders attacked and cannibalized males more frequently than sated females and only the latter ever remated. These differences in female behaviour influenced male mating strategies. Choice experiments demonstrated that males preferred to venture onto the silk threads of virgin rather than those of mated females. Similar patterns of mate selectivity were observed in the field; females with narrow abdomens attracted more males to the webs than females with broad abdomens, and copulations were observed more frequently among females with narrow abdomens. These smaller females are likely to be virgins that have recently molted. Males that preferentially mate with virgin females will not only avoid potentially fatal attacks but also obtain, on average, a higher fertilization success. 相似文献
275.
G. Schneider 《Die Naturwissenschaften》1981,68(11):535-541
During the last year, two earthquakes caused a great loss in human lives and much property damage in Algeria and Italy. These events raise the question of whether the engineering seismology methods currently in use are adequate. It can be shown that the seismic input parameters for planning and design of structures in earthquake-prone areas may be deduced from experience. The development of seismic response spectra on a statistical basis offers the possibility of making assumptions about future seismic loads taking the regional seismicity and the local underground situation into account. 相似文献
276.
Summary Seven neighborhoods adjacent to hazardous waste were surveyed. The authors found that respondents did not rate their neighborhoods as highly as Americans as a whole, but, like most Americans, they did rate their present neighborhood better, or the same as, their previous one. The adjacent hazardous waste site was mentioned as distressing more often than any other neighborhood characteristic. Yet in four of the seven neighborhoods, dilapidated buildings and streets, odors and smoke from sewage treatment plants and factories, noise from trains and traffic congestion, or another neighborhood characteristic was mentioned as more stressful than the hazardous waste site. It is argued that govemment needs to be more aggressive about understanding community viewpoints before proposing multi-million dollar hazardous waste remediation plans that could be resisted by a community.Professor Michael Greenberg and Dr Dona Schneider are regular contributors to this Journal. All three authors work in the Department of Urban Studies and Community Health, and support the New Jersey Graduate Program in Public Health at Rutgers University. 相似文献
277.
278.
279.
PD Dr. Rolf Altenburger Dr. Dana Kühnel Martin Bittens Dr. Birgit Daus Dr. Werner Brack Dr. Florian Centler Prof. Dr. Hauke Harms Dr. Martin Thullner Dr. Lukas Y. Wick Prof. Dr. Kai-Uwe Goss Prof. Dr. Frank-Dieter Kopinke Dr. Katrin Mackenzie Dr. Anja Miltner PD Dr. Matthias Liess Dr. Rainer Wennrich Dr. Anne E. Berns PD Dr. Peter Burauel 《Environmental Sciences Europe》2010,22(4):502-506
280.