全文获取类型
收费全文 | 238篇 |
免费 | 5篇 |
专业分类
安全科学 | 20篇 |
废物处理 | 1篇 |
环保管理 | 58篇 |
综合类 | 54篇 |
基础理论 | 54篇 |
污染及防治 | 39篇 |
评价与监测 | 9篇 |
社会与环境 | 6篇 |
灾害及防治 | 2篇 |
出版年
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 10篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 7篇 |
2013年 | 18篇 |
2012年 | 8篇 |
2011年 | 11篇 |
2010年 | 14篇 |
2009年 | 14篇 |
2008年 | 17篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 10篇 |
2004年 | 5篇 |
2003年 | 13篇 |
2002年 | 7篇 |
2001年 | 4篇 |
2000年 | 3篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1983年 | 4篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
排序方式: 共有243条查询结果,搜索用时 281 毫秒
101.
Authors of socioecological models propose that food distribution affects female social relationships in that clumped food
resources, such as fruit, result in strong dominance hierarchies and favor coalition formation with female relatives. A number
of Old World monkey species have been used to test predictions of the socioecological models. However, arboreal forest-living
Old World monkeys have been understudied in this regard, and it is legitimate to ask whether predominantly arboreal primates
living in tropical forests exhibit similar or different patterns of behavior. Therefore, the goal of our study was to investigate
female dominance relationships in relation to food in gray-cheeked mangabeys (Lophocebus albigena). Since gray-cheeked mangabeys are largely frugivorous, we predicted that females would have linear dominance hierarchies
and form coalitions. In addition, recent studies suggest that long food site residence time is another important factor in
eliciting competitive interactions. Therefore, we also predicted that when foods had long site residence times, higher-ranking
females would be able to spend longer at the resource than lower-ranking females. Analyses showed that coalitions were rare
relative to some other Old World primate species, but females had linear dominance hierarchies. We found that, contrary to
expectation, fruit was not associated with more agonism and did not involve long site residence times. However, bark, a food
with a long site residence time and potentially high resource value, was associated with more agonism, and higher-ranking
females were able to spend more time feeding on it than lower-ranking females. These results suggest that higher-ranking females
may benefit from higher food and energy intake rates when food site residence times are long. These findings also add to accumulating
evidence that food site residence time is a behavioral contributor to female dominance hierarchies in group-living species. 相似文献
102.
Gritta Veit-Köhler Marleen De Troch Mateja Grego Tania Nara Bezerra Wendy Bonne Guy De Smet Christina Folkers Kai Horst George Chen Guotong Rudy Herman Rony Huys Nikolaos Lampadariou Jürgen Laudien Pedro Martínez Arbizu Armin Rose Michaela Schratzberger Sybille Seifried Paul Somerfield Jan Vanaverbeke Edward Vanden Berghe Magda Vincx Borut Vriser Leen Vandepitte 《Marine Biology》2010,157(8):1819-1835
A large-scale database concerning benthic copepods from the Arctic, Baltic Sea, North Sea, British Isles, Adriatic Sea and Crete was compiled to assess species richness, biodiversity, communities, ecological range size and biogeographical patterns. The Adriatic showed the highest evenness and the most species-rich communities. Assemblages from the North Sea, British Isles, Baltic and Crete had a lower evenness. The British Isles were characterised by impoverished communities. The ecological specificity of copepod species showed two diverging trends: higher specificity of species in more diverse assemblages was observed in the Adriatic, North Sea and Baltic. A uniformly high species specificity disregarding sample diversity was found on Crete and in the British Isles. Benthic copepod communities showed distinct patterns that clearly fit the predefined geographical regions. Communities were distinguishable and β-diversity was found to be high around Europe, indicating a high species turnover on the scale of this investigation. The British Isles and the North Sea were found to be faunistic links to the Baltic and the Arctic. 相似文献
103.
Iserbyt Arne Eens Marcel Baetens Wendy Vermeulen Anke Müller Wendt 《Behavioral ecology and sociobiology》2017,71(4):1-15
Behavioral Ecology and Sociobiology - An individual’s home range, or how much space it requires to obtain resources and meet its needs for survival and reproduction, affects the scale of many... 相似文献
104.
105.
Correlates of male mating success in the ruff Philomachus pugnax,a lekking shorebird 总被引:1,自引:0,他引:1
Wendy L. Hill 《Behavioral ecology and sociobiology》1991,29(5):367-372
Summary Male ruffs (Philomachus pugnax), a lekking shorebird, can generally be divided into two morphs according to behavior and plumage coloration. Predominantly dark-colored, independent male ruffs defend small territories on a lek, whereas lighter colored satellite males are non-territorial and less site-faithful to a particular lek. The traits associated with the mating success of independent male ruffs were studied at two leks during two seasons on the island of Öland, Sweden in May and June of 1985 and 1987. Using multivariate analyses, three characteristics were found to be significantly related to mating success: high frequency of visits by satellites to an independent male's residence, consistency of lek attendance, and low rates of aggressive behavior. In contrast, mating success was unrelated to the degree of darkness of the independent male nuptial plumage, territory location on the lek, or rate of courtship displays. The use of multivariate analyses helped to resolve conflicting conclusions from previous studies which employed simple statistical analyses, or none at all. Experimental manipulations are suggested which will help to further determine the influence of female mate choice in this lekking system. 相似文献
106.
Wendy M. Jackson 《Behavioral ecology and sociobiology》1993,32(2):119-126
Summary Conspecific nest parasitism is a common reproductive strategy in the northern masked weaver (Ploceus taeniopterus). Parasites appear to be females with nests of their own who lay an additional egg in another female's nest as a way to enhance their reproductive success. Brood size in the northern masked weaver is practically constrained to three: starvation in four-chick broods is very common. The constraint on brood size is probably imposed by the extreme hatching asynchrony characteristic of this species: the last egg in a four-egg clutch hatches 72 h after the first egg, and when a chick starves, it is almost always the youngest chick. Late-hatching chicks also grow more slowly than do early-hatching chicks. If a female were to lay a fourth egg in her own nest, there is little chance that it would succeed. However; if she places it in another female's nest before that host lays her third egg, then it may have a greater chance of success. 相似文献
107.
Weapon size versus body size as a predictor of winning in fights between shore crabs, Carcinus maenas (L.) 总被引:4,自引:0,他引:4
Lynne U. Sneddon Felicity A. Huntingford Alan C. Taylor 《Behavioral ecology and sociobiology》1997,41(4):237-242
Relative body size (carapace width) and weapon size (chela length) were used as indicators of resource holding potential (RHP)
in the agonistic behaviour of male shore crabs, Carcinus maenas (L.). Weapon size was found to be a more reliable predictor of the outcome of pairwise fights than body size. Crabs with
longer chelae than their opponents were more likely to win fights than crabs with relatively larger bodies. Body size had
less influence on the outcome of fights. Relative body and weapon size did not influence initiation of contests but did affect
the likelihood of winning; however, this was significant only for weapon size. Winning crabs had heavier claws with greater
surface area than losing crabs. There was no relationship between relative size and fight duration. The frequency of cheliped
display increased with chela length and win- ners performed significantly more displays than losers.
Received: 5 February 1997 / Accepted after revision: 20 May 1997 相似文献
108.
Green sea turtles (Chelonia mydas) are renowned for their long-distance migrations but have less fame for short-distance migrations or non-migratory behavior. We present satellite telemetric evidence from Cocos (Keeling) Islands, Indian Ocean for the first predominantly non-migratory green sea turtle (C. mydas) population. The mean migration distance from the nesting beach to the foraging grounds was 35.5 km with a maximum mean transit time of 3.4 days. The behavior of this population has major implications for our general understanding of green turtle behavior and their life cycle and for conservation. Firstly, these results indicate a level of juvenile or adult non-breeding homing behavior from the open ocean to foraging grounds adjacent to their natal nesting beach. Secondly, a non-migratory breeding phase reduces the consumption of reproductive energy utilized, potentially resulting in higher fecundity for this population. Thirdly, the close proximity of the nesting and foraging habitats allows for uniformity in management and conservation strategies rarely possible for wide-ranging green turtle populations. 相似文献
109.
OBJECTIVE: The objective of this study is to evaluate the potential of high back booster seats to provide effective protection to children in side impacts. METHOD: This article presents a series of side impact sled tests at a velocity change of 30.5 km/h and a peak deceleration of 15.2 g, using the Hybrid III 6-year-old dummy in two styles of commonly used high-back booster seats: a conventional polystyrene booster seat and a convertible child restraint/booster seat. A series of tests were also performed using alternative anchorage systems in combination with the boosters. Simulated side impact tests were conducted at 90 degrees and 45 degrees. RESULTS: The booster seats tested were found to be too short for the 6-year-old dummy and head contact with the side door occurred in all 90 degree tests, resulting in high HIC values. The greatest potential for achieving effective protection in side impact in this test series was observed when the convertible child restraint/booster was used in combination with a rigid anchorage system. Using this system, the body of the dummy was kept farther away from the door which resulted in a softer head impact with the side door. CONCLUSIONS: Results from this work indicate that current booster seats offer poor torso containment and no head protection for children within the recommended age range. They also showed that the level of protection provided by belt positioning booster seats can be improved through the use of rigid anchorage systems. However, for this potential to be fully realized, belt positioning booster seats must offer better containment of the occupant during the impact. 相似文献
110.
Wendy L. Golden PhD Bernard F. Schneider Karen M. Gustashaw Majida N. Jassani 《黑龙江环境通报》1989,9(10):683-689
In two cases of prenatally detected cystic hygroma with oligohydraminos, successful cytogenetic diagnosis of Turner syndrome was achieved using cells obtained from direct aspiration of the cystic hygroma. Exceptionally high levels of alpha-fetoprotein were found in the cystic hygroma fluid, as might be expected. However, the maternal serum alpha-fetoprotein levels were within normal limits. Elevated alpha-fetoprotein levels in ‘amniotic fluid’ noted previously in the literature may have resulted because of inadvertent tapping of the cystic hygroma. It is clear from our cases that maternal serum levels of alpha-fetoprotein will not necessarily be elevated and will not serve as a screening mechanism for cystic hygromas. 相似文献