全文获取类型
收费全文 | 383篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
安全科学 | 1篇 |
废物处理 | 9篇 |
环保管理 | 11篇 |
综合类 | 222篇 |
基础理论 | 36篇 |
污染及防治 | 68篇 |
评价与监测 | 29篇 |
社会与环境 | 9篇 |
出版年
2017年 | 5篇 |
2016年 | 5篇 |
2014年 | 6篇 |
2013年 | 15篇 |
2012年 | 6篇 |
2011年 | 8篇 |
2010年 | 6篇 |
2009年 | 4篇 |
2008年 | 21篇 |
2007年 | 12篇 |
2006年 | 6篇 |
2005年 | 5篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 7篇 |
1997年 | 4篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1979年 | 5篇 |
1978年 | 7篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1969年 | 3篇 |
1968年 | 9篇 |
1967年 | 8篇 |
1966年 | 5篇 |
1965年 | 7篇 |
1964年 | 6篇 |
1963年 | 5篇 |
1961年 | 5篇 |
1958年 | 3篇 |
1957年 | 3篇 |
1956年 | 5篇 |
1954年 | 6篇 |
1952年 | 4篇 |
1943年 | 5篇 |
1934年 | 3篇 |
1924年 | 4篇 |
1919年 | 3篇 |
1918年 | 4篇 |
1917年 | 4篇 |
1913年 | 4篇 |
排序方式: 共有385条查询结果,搜索用时 15 毫秒
281.
282.
283.
284.
The Science of Nature - 相似文献
285.
The Science of Nature - 相似文献
286.
The main function of the spermatozoon is the transfer of the male haploid genome during fertilisation. In animals in general
and in fishes in particular, there is huge variation in sperm size. In fishes, sperm size ranges from 13 μm in Mugil cephlus to nearly 100 μm in the channel catfish Ictalurus punctatus. We examined intra-specific variation in sperm morphometry in the socially monogamous cichlid Pelvicachromis taeniatus using scanning electron microscopy. The mean total sperm length of nearly 70 μm was extraordinarily large for cichlids. Furthermore,
within-male variation was remarkably high. To our knowledge, P. taeniatus produces the longest cichlid sperm ever documented. Several hypotheses concerning the adaptive significance of these results
are presented. 相似文献
287.
Salminen-Paatero Susanna Thölix Laura Kivi Rigel Paatero Jussi 《Environmental science and pollution research international》2019,26(21):21511-21523
Environmental Science and Pollution Research - Radionuclides 137Cs and 90Sr and total beta activity were determined from air filters collected in Rovaniemi (Finnish Lapland) in 1965–2011.... 相似文献
288.
Sabine Grootenboer Claire Barro Thérèse Cynober P. Olivier Schischmanoff Jean-Marc Ayoubi Gil Tchernia Jean Delaunay Jean-Claude Pons 《黑龙江环境通报》2001,21(13):1114-1118
Dehydrated hereditary stomatocytosis (DHS) is a rare congenital hemolytic anemia. We observed that some patients had presented with different prenatal or perinatal forms of edema in some kindreds. Within weeks or months after birth, these exhibited a spontaneous, complete and definitive resorption. We assumed that some DHS patients, who were born without edema before ultrasound was available, might nonetheless have exhibited this during the prenatal period. The present report follows up the first pregnancy in a woman with overt DHS, but not herself having a known history of perinatal effusions. Ultrasound revealed that the fetus displayed ascites that disappeared prior to birth. The neonate had DHS. Prenatal edema must therefore be more frequent in DHS than known until now. DHS is another cause of prenatal edema to be considered in the differential diagnosis. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
289.
This study was supported by the Bundesministerium für Forschung und Technologie (BMFT), core program Einsatz neuer Technologien in den Geisteswissenschaften. 相似文献
290.
Timo Thünken Theo C. M. Bakker Sebastian A. Baldauf 《Behavioral ecology and sociobiology》2014,68(1):99-104
Kin discrimination in nepotistic as well as in sexual contexts is widespread in animals including humans. However, the underlying mechanisms of kin discrimination are assumed to vary between species and—within species—between contexts. During solitary life stages, kin recognition based on social learning is assumed to be less reliable because kin templates that are not continuously updated may get lost. Therefore, self-referent phenotype matching (“armpit effect”), i.e., the comparison of unknown phenotypes with own characteristics, should be particularly relevant when no social cues are available. However, experimental evidence for this mechanism is scarce. Here, we examine self-referent kin recognition in a mate-choice context in adult male Pelvicachromis taeniatus, a socially monogamous cichlid fish from West Africa with biparental brood care and pronounced kin-mating preferences. Juvenile P. taeniatus live in groups, whereas adult males compete for access to breeding sites which they aggressively defend against rivals. Using computer-animated females as standardized visual stimuli in combination with olfactory cues of related and unrelated females, we show that adult males reared isolated from kin since egg stage were able to discriminate sisters from unrelated females. As males could have learned kin cues only from themselves, our study provides evidence for self-referent kin recognition and indicates that the observed inbreeding preferences are mediated by self-derived olfactory cues. Male preferences for sisters were correlated with male body size. We discuss the implications of quality-related mate choice for the evolution of kin-mating preferences. 相似文献