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排序方式: 共有145条查询结果,搜索用时 15 毫秒
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Rogelio Cruz-Martínez Adolfo Etchegaray Saulo Molina-Giraldo Belen Nieto-Castro Enrique Gil Guevara Joaquin Bustillos Miguel Martínez-Rodríguez Alma Gámez-Varela Daniel Saldivar-Rodríguez Erendira Chávez-González Rodolfo Keller Ricardo Russo Eduardo Yepez-García Fausto Coronel-Cruz Johnatan Torres-Torres Alejandro Rojas-Macedo Daniel Ibarra-Ríos Ricardo Ordorica-Flores Jaime Nieto-Zermeño Manuel Alcocer-Alcocer 《黑龙江环境通报》2019,39(7):519-526
93.
We examine the role of food resources on split sex ratios in Formica exsecta. Models of resource-based sex allocation predict that greater resources will cause an increase in the production of reproductive females (gynes) and an increase in overall size of offspring. We experimentally increased food resources for a subset of colonies in a polygynous population with a very male-biased sex ratio. This increase in food availability caused colonies that were male specialists the prior year to switch to female production. Overall, a significantly greater proportion of food-supplemented colonies produced gynes, compared to control colonies. Moreover, food-supplemented colonies produced significantly larger workers and males (but not gynes), compared to those produced by control colonies. There was, however, no significant difference in the numerical productivity of food-supplemented and control colonies. We also measured the natural association between colony sex specialization and proximity to conifers, which typically harbor honeydew-bearing aphids (an important natural food source). In line with the view that resources play an important role for determining sex ratios in social insects, we found that female-producing colonies were significantly closer to conifers than were male-producing colonies. 相似文献
94.
Darcy L. Gray Rosaline Canessa Rick Rollins C. Peter Keller Philip Dearden 《Environmental management》2010,46(2):167-180
Marine protected areas (MPAs) and zoning plans require an understanding of stakeholders if they are to be successful at achieving
social and biological objectives. This study examines recreational boaters in a proposed MPA in British Columbia, Canada,
using the recreation opportunity spectrum (ROS) and models of recreation conflict as a basis for investigation. Boaters (n = 543) visiting the region during the summer completed face-to-face surveys. Results show variability in boater setting preferences,
supporting an ROS-based approach to MPA planning and zoning. While boaters as a whole placed the greatest importance on natural
settings, sailboat operators expressed stronger preferences for natural and quiet settings relative to motorboats, and motorboat
operators expressed stronger preferences for settings characterized by built facilities and extractive activities relative
to sailboats. Several marine activities emerged as sources of perceived conflict for boaters, including personal watercraft,
commercial whale watching vessels, and shellfish aquaculture. Our analysis indicates that while some of these may be addressed
through zoning, others are better addressed through education and communication. Recommendations for both MPA management and
future research are made. 相似文献
95.
Laurent Keller Liselotte Sundström Michel Chapuisat 《Behavioral ecology and sociobiology》1997,41(1):11-15
The relative number of workers and female sexuals fathered by two males mated with a queen were directly assessed using microsatellite
and allozyme markers in field colonies of the ants Formica exsecta and F. truncorum. In both species one of the two males consistently fathered more offspring than the other. There was, however, no evidence
that one male might be particularly successful in fathering a disproportionally high proportion of female sexuals relative
to the proportion of workers. Moreover, in F. exsecta, the proportions of worker pupae and worker adults fathered by each male did not differ significantly between cohorts. The
most likely explanation for this pattern is that females store different amounts of sperm from the two males they mated with.
Received: 10 January 1997 / Accepted after revision: 22 March 1997 相似文献
96.
Previous studies have shown that colony social organization in Solenopsis invicta is under strong genetic control. Colonies containing some proportion of workers with the Bb or bb genotypes at the gene Gp-9 display polygyne social organization (multiple reproductive queens per colony), whereas colonies with only BB workers express monogyne organization (single reproductive queen per colony). The hypothesis that the presence of workers bearing the b allele confers the polygyne social phenotype on a colony leads to the prediction that social organization can be manipulated by experimentally altering frequencies of adult workers bearing this allele. We did this by replacing queens in colonies of each social form with single queens of the alternate form, which differ in Gp-9 genotype. As worker Gp-9 genotype compositions changed, experimental colonies switched to the alternate social organization. These switches occurred when frequencies of workers with the b allele passed an identifiable threshold, such that colonies with fewer than 5% such workers behaved like monogyne colonies and those with more than 10% behaved like polygyne colonies. Our data thus confirm the prediction that colony social organization in this ant can be altered by manipulating adult worker genotype compositions, and thereby support the hypothesis that the expression of polygyny requires the presence of adult workers bearing the b allele at Gp-9. 相似文献
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