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911.
In the European Union (EU), waste management is almost totally regulated by EU directives, which supply a framework for national regulations. The main target in view of sustainability is the prevention of direct disposal of reactive waste in landfills. The tools to comply with these principles are recycling and material recovery as well as waste incineration with energy recovery for final inertization. The adaptation of the principles laid down in EU directives is an ongoing process. A number of countries have already enacted respective national regulations and their realization shows that recycling and incineration are not in competition but are both essential parts of integrated waste management systems. In the EU, the amount of residual waste available for energy recovery can supply approximately 1% of the primary energy demand. About 50% of the energy inventory of municipal solid waste (MSW) in most EU countries is of biogenic origin, and MSW is to the same extent to be looked upon as regenerative fuel. Hence part of the CO2 released from waste incineration is climate neutral. In the EU, this share could produce savings of the order of 1% of annual CO2 emissions if energy from MSW replaced that derived from fossil fuel.  相似文献   
912.
Brominated high-impact polystyrene (HIPS-Br), which contained decabromodiphenyl ether flame retardant, and brominated acrylonitrile butadiene styrene (ABS-Br), which contained bromine-containing epoxy-type flame retardant, were degraded at 450°C individually and in a 1/1 mixture by a thermal and catalytic procedure using folded sheet mesoporous (FSM) and ZSM-5 zeolite in liquid phase contact mode. The two polymers produced similar degradation oils but at a higher yield for HIPS-Br. However, the composition and distribution of Br-, N-, and O-containing compounds depended on the type of flame retardant in HIPS-Br and ABS-Br. Multiphase catalytic systems consisting of FSM in liquid phase contact mode and various CaH-, FeO-, CoMo-, and NiMo-based catalysts, or combinations of these catalysts, in vapor phase contact mode were used to decrease the amount of heteroatoms (Br, N, and O) in the degradation oils. Each system gave particular results in terms of mass balance and concentrations of heteroatoms. A FSM (liquid phase contact)/CaHC (vapor phase contact) combination was the best catalytic system to remove Br-, N-, and O-containing compounds from degradation oils.  相似文献   
913.
To evaluate the hazard of combined hydrogen/dust explosions under severe accident conditions in International Thermonuclear Experimental Reactor (ITER), standard method of 20-L-sphere was used to measure the explosion indices of 4-μm fine graphite dust in lean hydrogen/air mixtures. The mixtures were ignited by a weak electric spark. The tested fuel concentrations were 8–18 vol% H2 and 25–250 g/m3 dust. If the hydrogen content is higher than 10 vol%, the dust constituent can be induced to explode by the hydrogen explosion initiated by a weak electric spark. Depending on the fuel component concentrations, the explosions proceed in either one or two stages. In two-stage explosions occurring at low hydrogen and dust concentrations, the mixture ignition initiates first a fast hydrogen explosion followed by a slower phase of the dust explosion. With increasing dust concentration, the dust explodes faster and can overlap the hydrogen-explosion stage. At higher hydrogen concentrations, the hybrid mixtures explode in one stage, with hydrogen and dust reacting at the same time scale. Maximum overpressures of hybrid explosions are higher than those observed with hydrogen alone; maximum rates of pressure rise are lower in two-phase explosions and, generally, higher in one-stage explosions, than those characteristic of the corresponding H2/air mixtures.  相似文献   
914.
A modeling concept, based on a network of ideal reactor elements, is illustrated with tracer data for the Passaic River of New Jersey. This approach to simulation permits evaluation of mixing without detailed knowledge of internal processes or concentration profiles. The effect of dispersion can be superimposed on first-order decay processes, such as oxygen demand, and evaluated with this method. Application as a water quality management tool extends present use of this concept to wastewater treatment plant analyses.  相似文献   
915.
This study observed privacy-seeking behavior in an elementary classroom, investigated individual differences in privacy seeking, and compared preferences for private spaces varying in degree of enclosure. Four privacy booths were placed in a fourth-grade classroom. A ticket system was used to assess booth use. Information on personality and background variables was obtained with self-report, peer, teacher, and parent questionnaires. After an initial period of enthusiasm, overall booth use declined sharply. However, analysis revealed substantial individual variation in booth use that remained consistent throughout the study. For boys, booth use was significantly correlated with teachers' ratings of sociability, aggressiveness, and distractibility. For girls, a significant positive relationship was found between privacy seeking at home and in school. Self-reported desire for privacy was uncorrelated with actual privacy-seeking behavior in the classroom. No significant differences in the use of the various booths were found, although self-reported preferences clearly favored the booth that allowed visual access to the rest of the classroom when desired.  相似文献   
916.
917.
Two studies were conducted to examine distance classes of vegetation (foreground, middleground and background) and scene composition (presence of vegetation in left, center or right section of the image) as predictors of perceived scenic beauty. In study one, 41 students rated 63 landscape scenes with regard to scenic beauty. The Scenic Beauty Estimation Method was used to derive interval scale beauty values (SBEs). For each landscape image, areal measures of vegetation in each distance class and for each vertical section were taken and used as predictors. Presence of haze, clouds and human impacts were also recorded. Among the most important contributors to scenic beauty were amount of center middleground vegetation, and center background vegetation. Left foreground vegetation and right foreground vegetation were found to have significant and opposing regression weight signs—negative for the left and positive for the right. Study two was conducted to determine whether these opposing regression weight signs for foreground vegetation were due to a perceptual right-left bias or to some specific content in the image itself. In the second study, the photographic slides used to present landscape scenes to subjects were reversed so that the content which was previously on the right was now left, and vice versa. Thirty-nine students rated the reversed slides with regard to their scenic beauty. The signs of the regression weights in study two shifted such that left foreground was now positively valued and right foreground was negatively valued. This finding suggests that viewers are sensitive to foreground content and its placement in the image, and not simply to one side of the field of vision.  相似文献   
918.
An experimental survey was undertakento explore the links between thecharacteristics of a moral issue, the degree ofmoral intensity/moral imperative associatedwith the issue (Jones, 1991), and people'sstated willingness to pay (wtp) for policy toaddress the issue. Two farm animal welfareissues were chosen for comparison and thecontingent valuation method was used to elicitpeople's wtp. The findings of the surveysuggest that increases in moral characteristicsdo appear to result in an increase in moralintensity and the degree of moral imperativeassociated with an issue. Moreover, there was apositive link between moral intensity/moralimperative associated with an issue andpeople's stated wtp for policy to address theissue. The paper discusses the relevance of thefindings of the survey in the context of thedebate concerning the relationship betweenmoral and economic values and the use of thecontingent valuation method to estimatepeople's wtp of policy options with moraldimensions.  相似文献   
919.
There is an ongoing debate in animalethics on the meaning and scope of animalwelfare. In certain broader views, leading anatural life through the development of naturalcapabilities is also headed under the conceptof animal welfare. I argue that a concern forthe development of natural capabilities of ananimal such as expressed when living freelyshould be distinguished from the preservationof the naturalness of its behavior andappearance. However, it is not always clearwhere a plea for natural living changes overinto a plea for the preservation of theirnaturalness or wildness. In the first part ofthis article, I examine to what extent theconcerns for natural living meet ``theexperience requirement.' I conclude that someof these concerns go beyond welfare. In thesecond part of the article. I ask whether wehave moral reasons to respect concernsfor the naturalness of an animal's living thattranscend its welfare. I argue that the moralrelevance of such considerations can be graspedwhen we see animals as entities bearingnon-moral intrinsic values. In my view the``natural' appearance and behavior of an animalmay embody intrinsic values. Caring for ananimal's naturalness should then be understoodas caring for such intrinsic values. Intrinsicvalues provide moral reasons for action iffthey are seen as constitutive of the good lifefor humans. I conclude by reinterpreting,within the framework of a perfectionist ethicaltheory, the notion of indirect dutiesregarding animals, which go beyond andsupplement the direct duties towardsanimals.  相似文献   
920.
人因事故纵深防御系统模型   总被引:13,自引:2,他引:13  
复杂社会技术系统发展的特征对系统中人因产生了极大的影响。对该系统中人因事故的防范采取基于多米诺骨牌原理的对策已难奏效 ,而须采用技术手段、组织手段、文化手段融为一体的纵深防御策略。笔者提出并建立了一个主动型人因事故纵深防御系统模型 ,它包含 5个阶段 :方针确立、预测分析、事故减少策略、运行、反馈 ,突出主动去探查与辨识可能的人因事故 ,并采取技术、组织和文化相结合的措施达到减少和预防事故的目的。  相似文献   
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