全文获取类型
收费全文 | 137篇 |
免费 | 0篇 |
专业分类
安全科学 | 9篇 |
废物处理 | 2篇 |
环保管理 | 12篇 |
综合类 | 21篇 |
基础理论 | 48篇 |
污染及防治 | 24篇 |
评价与监测 | 12篇 |
社会与环境 | 9篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2011年 | 7篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 8篇 |
2007年 | 11篇 |
2006年 | 5篇 |
2005年 | 7篇 |
2004年 | 4篇 |
2003年 | 6篇 |
2002年 | 8篇 |
2001年 | 8篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有137条查询结果,搜索用时 93 毫秒
121.
Coexistence of species of Acartiidae (Copepoda) in the Cochin Backwater,a monsoonal estuarine lagoon 总被引:3,自引:0,他引:3
A study was made of copepods of the family Acartiidae which form the dominant component of the plankton in the Cochin Backwater (Kerala, India). At least nine species inhabit the backwater at one time or another, more than have been recorded for any other area. Reasons were sought for this diversity. The surface plankton was sampled from the head of the estuary to the mouth and from one season to another. There were large seasonal changes in salinity (0 to 35 ), due to monsoonal flooding, and associated changes in species composition. Species diversity was highest during the dry season and lowest in the wet. It is suggested that this annual catastrophic flooding leads, in the long run, to high species diversity by imposing a regular check on interspecific competition. 相似文献
122.
123.
Researchers have suggested the use of credibility intervals for identifying moderator effects in meta-analysis. In the present study, the accuracy of decisions derived from credibility intervals was determined from Monte Carlo generated correlations based on two series of meta-analyses, one containing 20 studies and the other, 100 studies. Within each study, the responses of 100 subjects were simulated. Although in some marginal cases the accuracy measures (Type I error rate and power) from the credibility intervals were better than those derived from the SH-75 per cent and U rules, the former technique was generally found to be a poor indicator of heterogeneity or homogeneity. Finally, the concept of a large interval was discussed and a rule of thumb for using it to detect moderators was suggested. 相似文献
124.
Lior C. Goldenberg Abraham J. Melloul Uri Zoller 《Journal of environmental management》1996,46(4):311-326
Based on the reality of (a) soil heterogeneity in the vadose zone, (b) enhanced desorption from soil and solubility in water of water insoluble contaminants in the presence of surfactants, and (c) wetting/drying cycles of groundwater recharge (a major cause of fractures formation), a coherent “short-cut” conceptual approach is advanced to account for enhanced groundwater contamination. This is an attempt to close the gap between theory, lab simulations and conventional modelling-based predictions, and observed higher concentrations and more rapid arrival times of contaminants reaching groundwater. Recent data concerning chloride ion and non-ionic surfactants concentrations in aquifers and groundwater wells, combined with previous results concerning the concentrations of tritium, chlorides, metals, organic hydrocarbons and surfactants in the unsaturated and saturated zones of Israel's aquifers, are accounted for in terms of the “short-cut” approach. The contradiction between predictions of groundwater contamination made with conventional, deterministic, homogeneous models and the actual observed behavior of contaminants in soils and aquifers is thus explaind. The “short cut” approach should not be perceived as a better type of model to guide modelling. Rather, it is a proposal for a conceptual change from the realistically invalid, but commonly accepted, conventional “buffer-protective soil/long-term groundwater contamination” to the “short cut” conceptual model to explain the enhanced groundwater contamination actually observed. Although the validity of the proposed approach is strongly supported by the data here presented for the case of Israel (serving as an illustrative case study), selected results and conclusions drawn from studies conducted worldwide suggest its general applicability and usefulness. A major conclusion evolved from the “short-cut” conceptual model is that contemporary groundwater management policies, based on the current perception of groundwater contamination processes and their modelling, may result in an irreversible detrimental effect on the environmental situation in the long run. In any case, prevention, rather than correction/remediation, is strongly recommended as the strategy of choice for rational long-term management of groundwater resources. 相似文献
125.
Paul M. Randall Abraham S.C. Chen 《Journal of the Air & Waste Management Association (1995)》2013,63(5):404-411
Abstract Two chromated copper arsenate (CCA) wood-treating plants were assessed for their waste reduction practices. The objectives of this study were to estimate the amount of hazardous wastes that a well-designed and well-maintained CCA treatment facility would generate and to identify waste reduction opportunities. These practices have been reflected in several areas, including facility designs, process controls, and management practices. The facility designs included enclosed treatment buildings, covered drip pads, a drip pan, an automatic lumber handling system, power rollers, computerized chemical mixing systems, spill containments, and air ventilation systems to minimize mist or droplet emissions from cylinders and work tanks. Management practices have included pretreatment quality control, improved housekeeping, resource recovery and recycling, and operator training. 相似文献
126.
Terry J. Dillon Abraham Horowitz John N. Crowley 《Atmospheric environment (Oxford, England : 1994)》2010,44(9):1186-1191
Although NF3, a trace gas of purely anthropogenic origin with a large global warming potential is accumulating in the Earth's atmosphere, little photochemical data exists from which to calculate its atmospheric removal rate. In this study, photodissociation quantum yields, Φ1, were derived following 193.3 nm laser photolysis of NF3, and quantitative conversion of the F-atom photoproducts to OH, which was detected by laser induced fluorescence. Values of Φ1(P, T) = (1.03 ± 0.05) were determined at pressures between 28 and 100 mBar of He or N2 and at either room temperature or 255 K. Absorption cross-sections, σ, obtained between 184 and 226 nm were combined with the values of Φ1(P, T) to confirm a long (≈700 year) photolysis lifetime for NF3. No evidence for reaction of OH with NF3 was found, indicating that this process makes little or no contribution to NF3 removal from the atmosphere. These results underpin recent calculations of an NF3 atmospheric lifetime τ ≈ 550 years, largely controlled by photolysis in the stratosphere. In the course of this work the rate coefficient k2(298 K) = (1.3 ± 0.2) × 10?11 cm3 molecule?1 s?1 was obtained for the reaction F + H2O. 相似文献
127.
Sigal Lahav Victoria Soroker Robert K. Vander Meer Abraham Hefetz 《Behavioral ecology and sociobiology》1998,43(3):203-212
This study compares two basic models for the origin and maintenance of colony gestalt odor in the polygynous ant species
Cataglyphis niger. In the first model, queens are centers of de novo biosynthesis and distribution of recognition odors (“queen-centered” model);
in the second, colony odors are primarily synthesized and distributed by workers (“worker-centered” model). We tested the
behavioral patterns that are predicted from each model, and verified by biochemical means the distributional directionality
of these signals. Encounters between nestmates originating from split colonies were as amicable as between nestmates from
non-split colonies; queenless ants were as aggressive as their queenright nestmates, and both were equally aggressed by alien
ants. These results indicate that queens have little impact on the recognition system of this species, and lend credence to
the worker-centered model. The queen-centered model predicts that unique queen substances should be produced in appreciable
quantities and that, in this respect, queens should be more metabolically active than workers. Analysis of the chemical composition
of postpharyngeal glands (PPGs) or cuticular extracts of queens and workers revealed high similarity. Quantitatively, queens
possessed significantly greater amounts of hydrocarbons in the PPG than workers, but the amount on the thoracic epicuticle
was the same. Queens, however, possess a lower hydrocarbon biosynthesis capability than workers. The biochemical evidence
thus refutes the queen-centered model and supports a worker-centered model. To elucidate the directionality of cue distribution,
we investigated exchange of hydrocarbons between the castes in dyadic or group encounters in which selective participants
were prelabeled. Queens tended to receive more and give less PPG content, whereas transfer to the epicuticle was low and similar
in all encounters, as predicted from the worker-centered hypothesis. In the group encounters, workers transferred, in most
cases, more hydrocarbons to the queen than to a worker. This slight preference for the queen is presumably amplified in a
whole colony and can explain their copious PPG content. We hypothesize that preferential transfer to the queen may reflect
selection to maintain her individual odor as close to the average colony odor as possible.
Received: 4 November 1997 / Accepted after revision: 5 February 1998 相似文献
128.
129.
This paper presents results of a social cost–benefit analysis (CBA) of afforestation and soil moisture treatment of common lands under an integrated watershed development programme in Karnataka State, India. The aim of the study was to find out if soil moisture conservation and afforestation measures were justified in terms of economic efficiency. The assessment was undertaken by calculating the economic internal rate of return (EIRR) for five village common lands in two watersheds, Uparhalla and Chinnahagari, in central Karnataka. Focused group discussions were organised, using a semi-structured questionnaire and various stakeholders, including project implementing agencies, self help groups and other community-based organisations. The attractiveness of the programme in both watersheds for landless and land owners was high in three out of five sampled villages, with an EIRR ranging from 19% to 91%, while two villages in Chinnahagari watershed had extremely low EIRR, reflecting poor management of soil moisture and afforestation interventions and lack of institutional cohesion to sustain investments made to develop common lands. Therefore, the CBA conducted in the KAWAD project, except for two villages, shows that the investment made to develop common lands should yield substantial economic returns in the long term under a business as usual scenario. 相似文献
130.
Merav Vonshak Tamar Dayan Julien Foucaud Arnaud Estoup Abraham Hefetz 《Behavioral ecology and sociobiology》2009,63(11):1667-1677
The little fire ant, Wasmannia auropunctata, constitutes one clonal supercolony throughout Israel, providing an opportunity to examine the effects of genotype versus
environment on nestmate recognition. Intraspecific encounters among field-collected or among laboratory-maintained colonies
were nonaggressive, but encounters between freshly collected and laboratory-maintained colonies were highly aggressive. Analyses
of cuticular hydrocarbons revealed that freshly field-collected colonies had distinguishable profiles. Moreover, freshly collected
colonies had profiles disparate from those of the same colonies after 4 months in the laboratory. These results indicate a
strong interplay between genetic-based and environmentally based effects on the recognition cues. We propose that in the field
the ants’ diet breadth is broad and consequently the incorporation of diet-borne substances is insufficient to mask the genetically
determined cues. In the laboratory, however, the restricted diet promoted the incorporation of alien hydrocarbons at high
levels, thus altering the genetically based cues to the point of alienation. These results shed a new light on the mechanisms
by which environmental cues may affect label and/or template formation in ants.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献