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651.
Pär Segerdahl 《Journal of Agricultural and Environmental Ethics》2007,20(2):167-193
Although the notion of natural behavior occurs in many policy-making and legal documents on animal welfare, no consensus has
been reached concerning its definition. This paper argues that one reason why the notion resists unanimously accepted definition
is that natural behavior is not properly a biological concept, although it aspires to be one, but rather a philosophical tendency
to perceive animal behavior in accordance with certain dichotomies between nature and culture, animal and human, original
orders and invented artifacts. The paper scrutinizes the philosophy of natural behavior as it developed in the organic movement
in response to a perceived contrast between industrialized and traditional agriculture. There are two reasons for focusing
on the organic movement: (i) the emphasis on “the natural” is most accentuated there and has a long history, (ii) everyday
life on organic farms presupposes human/animal interplay, which conflicts with the philosophical tendency to separate nature
from culture. This mismatch between theory and practice helps us see why, and how, the philosophy of natural behavior needs
to be reconsidered. The paper proposes that we understand farms as local human/animal cultures, and asks what we can mean
my natural behavior in such contexts. Since domestic animals adapt to agricultural environments via interaction with caretakers,
such interplay is analyzed as “hub” in these animals’ natural behavior. 相似文献
652.
The paper presents a semi-continuous preexposure procedure (SCEP) for use with surface water batch simulation biodegradability tests at low test substance concentrations (0.1-100 microg/l). Simple one step batch tests are normally used first of all for determining "initial rates" characteristic of the water as sampled, as by contrast to "adapted" rates obtained as a result of exposure of the microbial community to the test compound. The aim of the SCEP is to facilitate this adaptation and to become able to estimate reproducible "adapted rates" representing a steady state situation. This is accomplished by maintaining the microbial diversity and a supply of test substance and natural substrates. Conducting a SCEP involves regular renewal of part (e.g. one third) of the test suspension (e.g. every two weeks) adding freshly collected natural water with test compound of the initial concentration. An example study was performed with aniline, 4-nitrophenol, 2,4-dichlorophenoxyacetic acid, 4-chloroaniline, and water from the urban river M?lle?. Following preadaptation lag phases were considerably reduced and much more reproducible than obtained with simple batch tests. In tests at 100 microg/l lag phases for aniline decreased from 5.2 to <1 day, 4-nitrophenol from 10 to <1 day, 2,4-dichlorophenoxyacetic acid from 24 to <1 day, and 4-chloroaniline from 88 to 9 days, respectively. Adapted rates obtained with the SCECP were roughly the same as final rates in simple batch tests with successful adaptation. The adapted rate constant is perceived as an inherent characteristic of the test compound at a specific concentration and under environmental influence (temperature, natural substrates, etc.) but with no simple links back to the original microbial population. By contrast, the initial rates in one step batch tests are determined also by the microbial population initially present in the water sampled. 相似文献
653.
The cyanobacterial hepatotoxin nodularin is abundantly produced by the cyanobacterium Nodularia spumigena in the Baltic Sea during July-August. Nodularin is a potent hepatotoxin and a tumour promoter, distributed in various Baltic Sea environmental compartments, especially food webs involving mussels. Flounders receive nodularin through consumption of blue mussels. In this study nodularin concentrations in individual flounders (liver) were examined between July and September 2002 (six sample sets, four to 10 samples/set), providing information about contribution of sampling on estimates of bioaccumulation intensity. Toxin was determined using liquid chromatography/mass spectrometry (LC/MS) and enzyme-linked immunosorbent assay (ELISA). Additionally, liver histopathology was examined. Observed toxin concentrations were ND-390 microg kg(-1) dw (LC/MS) and 20-2230 microg kg(-1) dw (ELISA), with maximum concentrations in September (ELISA). The ELISA protocol generally resulted in higher, up to approximately 10-fold, toxin concentrations than LC/MS, with increasing difference toward September. This difference may have originated from different extraction solvents in LC/MS and ELISA, ion suppression in LC/MS, and temporal increase in nodularin metabolites detectable with ELISA. The differences in toxin concentrations between individual liver samples were considerable with relative standard deviation values of 20-154% (LC/MS) and 28-106% (ELISA). Since the precision of the ELISA method employed was <25% and that of LC/MS <10%, it can be concluded that the largest source of error in bioaccumulation estimates may be an inadequate number of samples. Although there were tissue lesions in several liver samples, occurrence of lesions was not related to toxin concentrations. 相似文献
654.
Assessing the environmental consequences of a chemical accident is a complex task. To date, the methods used to evaluate the environmental effects of an acute release of a chemical have often been based on measurements of chemical and physical variables deemed to be important, such as the concentration of the chemical. However, a broader strategy is needed to predict the environmental consequences of potential accidents during the planning process. An Environment-Accident Index (EAI), a simple tool based on such a strategy, has been developed to facilitate the consideration of a multitude of influential variables. The objectives of this study were to evaluate whether questionnaire-based expert panel's judgements could provide useful data on the environmental consequences of chemical spills, and an effective basis for further development of the EAI. As expected, the judgements did not agree perfectly, but they do give rough indications of the environmental effects, and highlight consistent trends that should be useful inputs for planning, prevention and decontamination processes. The different accidents were also judged to have caused everything from minor to very major effects in the environment, implying that a wide range of accident scenarios were represented in the material and covered by the EAI. Therefore, questionnaires and expert panel judgements can be used to collect useful data for estimating the likely environmental consequences of chemical accidents and for further development of the EAI. 相似文献
655.
Strandberg B Bandh C van Bavel B Bergqvist PA Broman D Ishaq R Näf C Rappe C 《Chemosphere》2000,40(9-11):1205-1211
Surface sediment, amphipods (Monoporeia affinis), isopods (Saduria entomon) and fourhorn sculpins (Oncocottus quadricornis) were collected at two coastal stations in the Gulf of Bothnia, one in the Bothnian Bay and the other in the Bothnian Sea. The objective was to study the concentrations, composition profiles, bioaccumulation features and spatial differences of organochlorine compounds such as hexachlorocyclohexanes (HCHs), DDTs, hexachlorobenzene (HCBz), chlordanes (CHLs), dieldrin, Mirex and polychlorinated biphenyls (PCBs). All groups of compounds were found in every sample investigated, with the exception of Mirex that was not detected in the sediment samples. The concentrations for e.g. PCBs and CHLs ranged from 700 to 2400 and 70 to 400 ng/g lipid in the specimens. For the corresponding sediments the results were 9.0-9.3 ng/g dw for PCBs and 0.54-0.57 ng/g dw for CHLs, respectively. Bioaccumulation differences between the species with regard to both degree of and type of compound were observed. The highest accumulation potential was found for the cyclodiene compounds including CHLs and Mirex in isopod. Finally, there were only small concentration and bioaccumulation differences between the two stations. 相似文献
656.
Tommy Gärling Anita Svensson-Gärling Jaan Valsiner 《Journal of environmental psychology》1984,4(3):235-252
One hundred and five parents and nonparents responded to a questionnaire consisting of evaluative ratings (general evaluation, social status and safety concern) of six familiar residential neighborhoods; ratings of the traffic accident risk children in the age ranges 2–4, 5–6, 7–9 and 10–12 years run in these neighborhoods; and, finally, ratings of the strengths attributed to factors as causes of traffic accidents (environment, children, parents, drivers and chance). Across neighborhoods and age ranges of children, risk perceptions were found to be related to the rated strengths of the causes. Low-traffic volume neighborhoods were perceived as less risky and were attributed as less strong causes than high-traffic volume neighborhoods were. Perceived risk increased with age of child to a maximum, then decreased. The same relationship with age was found for the attributed causes environment and drivers. The strength of parents as cause was rated to decrease while the strength of child as cause was rated to increase with age. Chance was rated as the weakest cause and the rated strength did not vary across neighborhoods or age. Neither parentship nor gender, singly or in combination, had any clear effects. For parents and nonparents alike the general evaluation of the neighborhoods was influenced by safety concern but not by the particular aspect investigated, i.e. perceived traffic accident risk to children. 相似文献
657.
Female nutritional state affects the rate of male incubation feeding in the pied flycatcher Ficedula hypoleuca 总被引:2,自引:0,他引:2
Smith H. G. Källander H. Hultman J. Sanzén B. 《Behavioral ecology and sociobiology》1989,24(6):417-420
Summary Male pied flycatches Ficedula hypoleuca regularly feed their mates during incubation. By experimentally supplying some females with extra food we studied how the female's nutritional state affected her incubation schedule and the rate at which her mate fed her. Females that received extra food spent more time on the nest and shorter periods away from it, compared with control females. This suggests that nest attentiveness is governed by the amount of energy available to the female. When females reccived extra food, males decreased their rate of incubation feeding. They also did so in response to increasing ambient temperatures, whereas incubation schedules were unaffected. We, therefore, conclude that our results support the female nutrition hypothesis, i.e., that the food provided by the male constitutes a significant nutritional contribution to the incubating female. 相似文献
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