全文获取类型
收费全文 | 979篇 |
免费 | 11篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 24篇 |
废物处理 | 24篇 |
环保管理 | 224篇 |
综合类 | 102篇 |
基础理论 | 275篇 |
污染及防治 | 275篇 |
评价与监测 | 33篇 |
社会与环境 | 31篇 |
灾害及防治 | 5篇 |
出版年
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 27篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 70篇 |
2012年 | 39篇 |
2011年 | 41篇 |
2010年 | 26篇 |
2009年 | 48篇 |
2008年 | 36篇 |
2007年 | 47篇 |
2006年 | 37篇 |
2005年 | 30篇 |
2004年 | 37篇 |
2003年 | 45篇 |
2002年 | 29篇 |
2001年 | 23篇 |
2000年 | 31篇 |
1999年 | 30篇 |
1998年 | 32篇 |
1997年 | 23篇 |
1996年 | 24篇 |
1995年 | 13篇 |
1994年 | 24篇 |
1993年 | 22篇 |
1992年 | 8篇 |
1991年 | 9篇 |
1990年 | 15篇 |
1989年 | 9篇 |
1988年 | 10篇 |
1987年 | 8篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 6篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 8篇 |
1977年 | 6篇 |
1976年 | 4篇 |
1973年 | 3篇 |
1967年 | 4篇 |
1965年 | 3篇 |
排序方式: 共有993条查询结果,搜索用时 15 毫秒
91.
Rainer Brüggemann Gerhard Ginzel Christian Steinberg 《Environmental Sciences Europe》1997,9(6):339-343
Conflict are frequently observed when drinking water protection areas are to be defined and when many variants of how to protect these area are to be found. Using ten potential scenarios, a method is presented here which shows how such conflicts concerning these variants may be handled in a systematic manner. The technique is derived from the use of partially ordered sets and their visualization by Hasse diagrams. The first step is to define rankings of different variants according to each aim of protection. A further step is to define an appropriate relationship of order. It is then possible to visualize the extent of consensus and of dissension through the use of a Hasse diagram. The final step is to quantify the importance of each protection aim and the initialization of an iteration. Should a complete consensus be found, this would result in a chain of (connected) variants. Should a complete dissension be found on the other hand, an antichain would then result (i.e. where all variants are isolated). 相似文献
92.
From 35 therapeutic abortions performed because rubella had occurred at 2–19 weeks of pregnancy, 120 fetal organs, 12 specimens of mixed products of conception, and 15 placentae were tested for rubella virus. Virus was isolated from 10 out of 11 fetuses (91 per cent) from women infected at 2–8 weeks, from 5 out of 8 (63 per cent) infected at 9–10 weeks, and from 2 out of 16 (13 per cent) infected at 11–19 weeks. Hybridization tests for viral RNA on 39 fetal organs from eight cases revealed infection in four additional fetuses. Virus was isolated from only 3 out of 15 aborted placentae, but hybridization tests on six placentae revealed infection in three additional specimens. Hybridization was superior to virus isolation for detecting rubella infection in products of conception and is therefore potentially the better method for examining chorionic villus biopsies. Rubella virus was isolated from the throats of 4 out of 9 infants (44 per cent) infected during the first 12 weeks of gestation, but from none of 13 infected after 17 weeks. Infants in the latter group are unlikely to infect susceptible contacts. 相似文献
93.
Stefan Pudenz Rainer Brüggemann Kristina Voigt Gerhard Welzi 《Umweltwissenschaften und Schadstoff-Forschung》2003,15(1):20
Zur Unterstützung von Bewertungs- und Entscheidungsprozessen über die Nachhaltigkeit von Managementstrategien, deren Auswirkungen
durch unterschiedlich dimensionierte Indikatoren gemessen werden, gibt es verschiedene mathematische Methoden. In diesem Beitrag
werden die Prinzipien dieser sog. multikriteriellen Bewertungs- und Entscheidungshilfeinstrumente beispielhaft anhand einer
Auswahl von Strategien für ein Nachhaltiges Wassermanagement vorgestellt, sowie Vor- und Nachteile herausgearbeitet. Es wird
gezeigt, dass sich die Verfahren insbesondere in Transparenz, Objektivit?t und durch den Grad an Partizipation durch Akteure
z.T. erheblich unterscheiden. W?hrend die Hassediagrammtechnik sich an den naturwissenschaftlich begründbaren Datenmatrix
orientiert und somit eine objektive und transparente Bewertung und Datenanalyse liefert, haben Konkordanzanalyse, Nutzwertanalyse,
PROMETHEE und AHP ihre St?rken in der M?glichkeit, Akteure bzw. Stakeholder am Entscheidungsprozess partizipieren zu lassen.
*** DIRECT SUPPORT *** A00OI029 00003 相似文献
94.
95.
96.
In view of their possible involvement in ammonium assimilation in the coral/algal symbiosis, we have purified two distinct glutamate dehydrogenase isoenzymes from the symbiotic dinoflagellate Symbiodinium microadriaticum (Freudenthal) extracted from the staghorn coral Acropora formosa collected from Magnetic Island, North Queensland, Australia, in 1986–1987. An NADPH-specific glutamate dehydrogenase (GDH) displayed biphasic kinetics with respect to ammonium as the variable substrate; at low substrate concentrations the apparent K
m was below 1 mM, whereas at high substrate concentrations the corresponding value was approximately 200 mM. The NADPH-GDH displayed extremely low activity in the direction of glutamate oxidation; together with the kinetic data this suggests a probable role in ammonium assimilation. A second (NADH-specific) GDH was found to have both amination and deamination activities, and presumably functions in vivo in glutamate oxidation. Kinetic constants are reported for both GDH isoenzymes. 相似文献
97.
98.
99.
A Konoplev S Kaminski E Klemt I Konopleva R Miller G Zibold 《Journal of environmental radioactivity》2002,58(1):1-11
The methodology for estimating radiocaesium distribution between solid and liquid phases in lakes is applied for three prealpine lakes: Lake Constance (Germany), Lake Lugano (Switzerland) and Lake Vorsee (Germany). It is based on use of the exchangeable distribution coefficient and application of the exchangeable radiocaesium interception potential (RIPex). The methodology was tested against experimental data. Good agreement was found between estimated and measured 137Cs concentrations in Lake Constance and Lake Lugano, whereas for Lake Vorsee a discrepancy was found. Bottom sediments in Lake Vorsee are composed mainly of organic material and probably cannot be described in terms of the specific sorption characteristics attributed to illitic clay minerals. 相似文献
100.
H. F. Frolander C. B. Miller M. J. Flynn S. C. Myers S. T. Zimmerman 《Marine Biology》1973,21(4):277-288