全文获取类型
收费全文 | 310篇 |
免费 | 0篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 3篇 |
废物处理 | 4篇 |
环保管理 | 27篇 |
综合类 | 220篇 |
基础理论 | 21篇 |
污染及防治 | 34篇 |
评价与监测 | 4篇 |
社会与环境 | 1篇 |
出版年
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 7篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1984年 | 5篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1975年 | 5篇 |
1968年 | 4篇 |
1964年 | 3篇 |
1963年 | 6篇 |
1961年 | 9篇 |
1960年 | 6篇 |
1959年 | 5篇 |
1958年 | 11篇 |
1957年 | 6篇 |
1955年 | 6篇 |
1954年 | 5篇 |
1953年 | 3篇 |
1947年 | 3篇 |
1943年 | 5篇 |
1941年 | 5篇 |
1939年 | 4篇 |
1938年 | 5篇 |
1937年 | 4篇 |
1935年 | 4篇 |
1934年 | 4篇 |
1933年 | 3篇 |
1932年 | 3篇 |
1929年 | 3篇 |
1928年 | 5篇 |
1926年 | 3篇 |
1925年 | 3篇 |
1923年 | 6篇 |
1921年 | 3篇 |
1920年 | 3篇 |
1919年 | 5篇 |
1916年 | 3篇 |
1915年 | 3篇 |
1914年 | 6篇 |
1913年 | 5篇 |
排序方式: 共有314条查询结果,搜索用时 15 毫秒
91.
Dr. Ernst Telschow 《Die Naturwissenschaften》1940,28(49):753-758
Das Jahr 1939 brachte mit dem Ausbruch des großen Kampfes um Deutschlands Freiheit und Zukunft auch für die Kaiser Wilhelm-Gesellschaft die Notwendigkeit gewisser Umstellungen, jedoch wird hiervon die der Tradition der Gesellschaft entsprechende Grundlagenforschung in keiner Weise berührt. Die folgenden Ausschnitte aus der Tätigkeit der Gesellschaft und ihrer Institute beweisen, daß die ihrem Aufbau zugrunde liegenden Gedanken — die ihren ersten Vorkämpfer schon inAlexander von Humboldt gefunden haben — auch in der jetzigen Zeit ihre Gültigkeit behalten, eine Tatsache, die im Hinblick auf die 30. Wiederkehr des Gründungstages der Kaiser Wilhelm-Gesellschaft am 11. Januar 1941 von besonderer Bedeutung ist. 相似文献
92.
Life-cycle phases of a zinc- and cadmium-resistant ecotype of Silene vulgaris in risk assessment of polymetallic mine soils 总被引:5,自引:0,他引:5
Short-term exposure of plants to heavy metals is often used for risk assessment of metal-enriched soils (OECD guideline 208) without considering the reliability of the assessment for long-term exposure, i.e. for the completion of a plant's life-cycle. In the present study with 15 orogenic soils three phases of the life-cycle of a Zn-Cd-resistant ecotype of Silene vulgaris were studied to improve risk assessment of metal-enriched soils. The first phase, i.e. emergence of seedlings was not related to the water-soluble or total metal concentration of the soils. Seedling mortality was low as long as the water-soluble metal concentration did not surpass 0.15 micromol Zn and 0.04 micromol Cu g(-1) dry soil. Curtailment of the life-cycle prior to flowering, i.e. the vegetative growth as second phase, occurred on those soils where roots and shoots were heavily enriched by Zn already in the seedling phase. In the third phase, i.e. the generative phase, time to flowering and yield differences between orogenic soils were substantial, but soil metal concentrations could not be directly related to timing of reproduction or biomass. Ranking of data showed a high inconsistency of the responses to metal exposure during the first phases of the life-cycle. It is concluded that total plant mass and seed mass are the only realistic endpoints of life-cycle bioassays in risk assessment as long as ranks are inconsistent between two successive early phases of the life-cycle. 相似文献
93.
Intrauterine treatment of 4 fetuses with urethral obstruction was attempted in the third trimester of pregnancy. The fetuses displayed varying sonographic findings including pyelectasis, caliectasis, hydroureter, bladder dilatation, ascites, hydrops, missing kidneys and oligohydramnios. Ultrasonically guided aspiration from the dilated structures was carried out to relieve pressure on the kidney parenchyme and to collect fluid samples for diagnostic purposes. Amino acid concentrations in the fetal urine showed a pattern similar to plasma in 2 fetuses, a pattern almost like urine in 1 fetus and an intermediate pattern in the 4th fetus. Only the fetus with normal amino acid concentrations in the urine survived: the other 3 died in uremia shortly after birth. In 3 cases cells from the aspirated urine were cultured and used for chromosome analysis. The cell cultures grew fast and karyotyping was possible within 1 week. In 2 fetuses an intrauterine catheter was inserted to drain the kidney permanently into the amniotic cavity. In the first case the catheter was displaced to the fetal abdomen after some days of successful drainage. In the second case the catheter tore the placenta, and the child had to be delivered immediately. 相似文献
94.
95.
96.
97.
Time series of polychlorinated dioxins and furans (PCDD/F) and polychlorinated biphenyls (PCB) in ambient air of a large conurbation in North-Western Germany are presented and analyzed. The trend of PCDD/F concentrations, starting from as early as 1988, shows a pronounced decrease by at least one order of magnitude, demonstrating that the emission reductions were effective. The PCDD/F depositions also have decreased by a factor of 5 since 1992. However, both trends have leveled out since 2005. Time series of PCB concentrations and depositions starting in 1994 show only slight decreases for the concentrations and almost no decrease for the depositions. From the decay rates following first order kinetics, half-lives in the order of 5-15 years for the PCDD/F and 15-31 years for the sum of the six indicator PCB could be calculated, which are much longer than the half-lives estimated from their reactivity towards the OH radical. Apparently, small fresh emissions (PCDD/F), considerable secondary emissions and evaporation from contaminated soils slow down their decay in the atmosphere of big conurbations. Analyzing the decay rates of individual PCB congeners shows that the lower chlorinated and more volatile ones are removed faster than the higher chlorinated congeners, probably via gas phase reactions with the OH radical. It can be concluded from the present study that the input of PCDD/F and PCB into the food chain via the air path will continue for another one or two decades in big conurbations. 相似文献
98.
99.
100.