全文获取类型
收费全文 | 228篇 |
免费 | 1篇 |
国内免费 | 2篇 |
专业分类
安全科学 | 7篇 |
废物处理 | 8篇 |
环保管理 | 6篇 |
综合类 | 88篇 |
基础理论 | 62篇 |
环境理论 | 1篇 |
污染及防治 | 50篇 |
评价与监测 | 5篇 |
社会与环境 | 4篇 |
出版年
2021年 | 3篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 5篇 |
2010年 | 7篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 15篇 |
2006年 | 6篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 4篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 4篇 |
1991年 | 3篇 |
1990年 | 9篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1972年 | 2篇 |
1970年 | 2篇 |
1969年 | 3篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 5篇 |
1965年 | 4篇 |
1964年 | 3篇 |
1963年 | 4篇 |
1962年 | 4篇 |
1961年 | 2篇 |
1960年 | 7篇 |
1959年 | 4篇 |
1958年 | 2篇 |
1957年 | 2篇 |
1955年 | 5篇 |
1954年 | 1篇 |
1946年 | 1篇 |
排序方式: 共有231条查询结果,搜索用时 78 毫秒
151.
Srividya Iyer Ruchir Shah Ashima Sharma Dieter Jendrossek Anjana Desai 《Journal of Polymers and the Environment》2000,8(4):197-203
The extracellular poly(-hydroxybutyrate) (PHB) depolymerase of Aspergillus fumigatus Pdf1 was purified by a new, simple, one-step affinity chromatography method using the substrate PHB. The purified enzyme was glycosylated, with the molecular mass of 40 KD, and exhibited a novel self-aggregation behavior by means of hydrophobic interaction that was resolved by Triton X-100 (TX-100) pretreatment of enzyme and also TX-100 incorporation in the native gel. The apparent K
m value of purified enzyme for PHB was 119 g/mL and 3-hydroxybutyrate was detected as the main endproduct of PHB hydrolysis. The depolymerase was insensitive to phenylmethyl sulfonyl fluoride (PMSF), sodium azide, ethylenediaminetetraacetic acid (EDTA), and para-chloromercuric benzoic acid (PCMB), but was inactivated by dithioerythritol (DTT) and showed specificity for short chain-length poly(-hydroxyalkanoates) (PHAs) such as PHB, poly(hydroxyvalerate) (PHV), and copolymers of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV). Medium-chain-length PHA failed to get hydrolyzed. The enzyme, however, exhibited strong cross reactivity with the Comamonas sp. PHB depolymerase antibodies, but not with PHV depolymerase antibodies of Pseudomonas lemoignei. Southern hybridization and dot blot analysis of A. fumigatus Pdf1 genomic DNA with alkaline phosphatase labeled probes of P. lemoignei PHB and PHV depolymerase genes revealed no homology, although the enzyme hydrolyzed both PHB and PHV. 相似文献
152.
Zusammenfassung Mit einem Bioaktivit?tssensor kann die Aktivit?t der Mikroorganismen im Belebtschlamm gemessen werden. Das Signal des Sensors
reagiert empfindlich auf eine Ver?nderung des Substratangebots und das Auftreten von toxischen Stoffen. Mit dem Bioaktivit?tssensor
ist es damit einerseits m?glich,online die Belebungsstufe hinsichtlich ihrer mikrobiellen Aktivit?t zu kontrollieren und andererseits die zuflie?enden Abw?sser
bezüglich ihres toxischen Potentials zu überwachen.
相似文献
153.
Dr Ingo Kennerknecht Sabine Krämer Dieter Grab Rainer Terinde Walther Vogel 《黑龙江环境通报》1993,13(4):257-269
Data in the literature suggest that confined placental mosaicism might be associated with intrauterine growth retardation. However, this association may be coincidental and due to bias of ascertainment. We therefore started a prospective study based on the cytogenetic evaluation of placentae derived from growth-retarded newborns. We further minimized possible bias by excluding those small-for-date infants displaying findings which already could explain intrauterine growth retardation (mothers who are smokers, multiple pregnancies, gestosis, dysmorphic infants). In a collection of 71 small-for-gestational age newborns, we did not see a single case of true confined placental mosaicism. 相似文献
154.
Biodegradation behavior and material properties of aliphatic/aromatic polyesters of commercial importance 总被引:2,自引:0,他引:2
Uwe Witt Rolf- Joachim Müller Wolf- Dieter Deckwer 《Journal of Polymers and the Environment》1997,5(2):81-89
Copolyesters of aliphatic monomers with a defined amount of terephthalic acid recently have been shown to be biodegradable.
This group of plastic materials exhibits very interesting material properties with regard to their technical application potential.
A tensile strength of 25 N/mm2 combined with elongations at break up to 1500% was achieved for BTA materials. Melting points varied from 80 to 140‡C. Biodegradation
rate under compositing conditions were determined, showing typical erosion rates of films, in the range of 5 to 10 Μm/week.
The material properties and the degradation rate as well can be adjusted by the copolymer composition. Stretching of the polymer
in the cold state leads to 10-fold higher mechanical strength of the material. The polyester chain can be extended to high
molar masses, resulting in melt viscosities suitable, e.g., for melt below extrusion. 相似文献
155.
156.
Klaus-Michael Wollin Helmut Höring Hermann H. Dieter 《Environmental Sciences Europe》1996,8(5):261-266
Risk assessment of contaminated sites from abandoned ammunition plants follows a multi-stage procedure with its own specific requirements for the toxicological assessment of chemical contaminants. Thus, the 22 explosives and related compounds (STVs) were classified according to carcinogenicity, genotoxicity and evaluation numbers for their toxicological potential (ENs). These characteristics permit a specific toxicological assessment and ranking at the stage of “historical reconnaissance”, independent of an evaluation of the contaminant concentrations. With a view to “orientative site evaluation” for the assessment of explosives and related compounds in groundwater and drinking water, toxicologically related guide values based on the ENs of toxicological potential as well as TDI-based guide values for STVs in soil were derived as based on toxicologically safe body doses and lifelong exposure (TDI=Tolerable Daily Intake). For regulatory purposes, substance related precautionary values are defined for probable carcinogens and contaminants with essential lacks in the toxicological data base. 相似文献
157.
158.
Martha M. Robbins Andrew M. Robbins Netzin Gerald-Steklis H. Dieter Steklis 《Behavioral ecology and sociobiology》2007,61(6):919-931
Over the past few decades, socioecological models have been developed to explain the relationships between the ecological
conditions, social systems, and reproductive success of primates. Feeding competition, predation pressures, and risk of infanticide
are predicted to influence how female reproductive success (FRS) depends upon their dominance rank, group size, and mate choices.
This paper examines how those factors affected the reproductive success of female mountain gorillas (Gorilla beringei beringei) of the Virunga Volcanoes, Rwanda from 1967–2004. Reproductive success was measured through analyses of interbirth intervals,
infant survival, and surviving infant birth rates using data from 214 infants born to 67 females. Mountain gorillas were predicted
to have “within-group scramble” feeding competition, but we found no evidence of lower FRS in larger groups, even as those
groups became two to five times larger than the population average. The gorillas are considered to have negligible “within-group
contest” competition, yet higher ranked mothers had shorter interbirth intervals. Infant survival was higher in multimale
groups, which was expected because infanticide occurs when the male dies in a one-male group. The combination of those results
led to higher surviving birth rates for higher ranking females in multimale groups. Overall, however, the socioecological
factors accounted for a relatively small portion of the variance in FRS, as expected for a species that feeds on abundant,
evenly distributed foliage. 相似文献
159.
160.