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821.
选用生活垃圾作为试验物料,利用铝甑试验台、元素分析、红外分析(FTIR)等方法,对不同温度下垃圾热解液体产物的性质进行研究。结果表明:热解终温600℃,升温速率20℃/min时垃圾的热解液产率最高;600℃的垃圾热解油含氧量最低,为20.28%,热值达到31.42 MJ/kg;各温度下垃圾热解液的含水率为20%~30%,酸值大于30 mg/g(KOH),灰分在600℃时达到最大,为0.25%;通过热解油的FTIR分析,垃圾热解油中含有酚类、醛类、羧酸类、酮类、芳香烃类、脂肪族等多种组分,其中600℃下垃圾热解油的芳香烃类物质较多,羧酸类物质较少。  相似文献   
822.
潘忠成  李敏 《环境工程》2016,34(1):126-129
碱性过硫酸钾氧化紫外分光光度法(HJ 636—2012)测定水中总氮时,经常出现空白值偏高的现象。为此,从总氮的测定过程出发,探讨了影响总氮测定的因素。结果表明:过硫酸钾的纯度对空白值的影响最大;氢氧化钠的纯度对空白值也有一定的影响;实验中可用去离子水代替无氨水;当室温超过27℃时,碱性过硫酸钾溶液的存放时间最好不超过3 d;不同的消解设备对空白值的影响不明显。  相似文献   
823.
针对我国现有环境风险评价体系中缺乏对自然环境、人工环境损失进行量化评价这一问题,在以往研究的基础上,建立了符合我国特点的受体易损性区划指标体系与量化模型,结合事故影响预测,建立了风险值计算方法,并提出了基于Bootstrap算法的环境风险可接受水平确定方法,由此构建了一套新的环境风险综合评价方法体系。  相似文献   
824.
Solar energy is one of the major sources of alternative and green energies that humanity need now and will continue to need in the future. There are now a large number of R&D activities on solar power generation facilities and equipment around the world. Located in a subtropical region, Taiwan is rich in solar energy resources; therefore, how to effectively use and store solar energy is a research topic of great interest to Taiwan. The main purpose of this study explores the economic benefits of building-integrated photovoltaics (BIPV) facilities and equipment by analyzing the net present values (NPV) and payback period of the BIPV façade of a shopping mall in Taiwan over its lifecycle. The NPV and payback period analysis results both indicate that the BIPV façade in the case study reaches its breakeven point within 10 years of payback period and 16 years of NPV during a life cycle of 20 years. By showing BIPV investments can bring an acceptable range of benefits profits, this study hopes to provide references for promoting the photovoltaic (PV) industry.  相似文献   
825.
Decisions concerning the appropriate listing status of species under the U.S. Endangered Species Act (ESA) can be controversial even among conservationists. These decisions may determine whether a species persists in the near term and have long‐lasting social and political ramifications. Given the ESA's mandate that such decisions be based on the best available science, it is important to examine what factors contribute to experts’ judgments concerning the listing of species. We examined how a variety of factors (such as risk perception, value orientations, and norms) influenced experts’ judgments concerning the appropriate listing status of the grizzly bear (Ursus arctos horribilis) population in the Greater Yellowstone Ecosystem. Experts were invited to complete an online survey examining their perceptions of the threats grizzly bears face and their listing recommendation. Although experts’ assessments of the threats to this species were strongly correlated with their recommendations for listing status, this relationship did not exist when other cognitive factors were included in the model. Specifically, values related to human use of wildlife and norms (i.e., a respondent's expectation of peers’ assessments) were most influential in listing status recommendations. These results suggest that experts’ decisions about listing, like all human decisions, are subject to the use of heuristics (i.e., decision shortcuts). An understanding of how heuristics and related biases affect decisions under uncertainty can help inform decision making about threatened and endangered species and may be useful in designing effective processes for protection of imperiled species.  相似文献   
826.
Understanding what shape values (which ultimately shape human behavior) will help improve the effectiveness of conservation solutions that depend on public support. To contribute to this understanding, we investigated the influence of societal‐level changes, such as modernization, on values in a multilevel framework. We collected survey responses (n = 4183) to questionnaires mailed to a random selection of households within each county in Washington (U.S.A.) (response rate 32%). We used multilevel modeling to determine the relationship between modernization (e.g., county‐level urbanization, wealth, and education) and wildlife value orientations (values that shape thought about wildlife) while controlling for individual‐level sociodemographics. We then explored how values influence conservation support at different levels (e.g., individual and county) and how values explain conservation support in a case study of public responses to wolf (Canis lupis) recovery. We found positive associations between county‐level examples of modernization and mutualism (a wildlife value orientation that prioritizes the perceived needs of wildlife) independent of a respondent's sociodemographics, and negative associations between modernization and domination (a wildlife value orientation that prioritizes human needs). Our results suggest that context has an additive impact on one's values; certain locations exhibited domination values, whereas others exhibited a mix of value types. This finding is important because actions that restrict human interests to promote biodiversity were negatively associated with domination and positively associated with mutualism. In the wolf case study, mutualism was strongly correlated with less social conflict over wolf recovery in many, but not all, counties (e.g., Pearson's r correlation = 0.59 in one county and a nonsignificant correlation in another). Our findings suggest that modernization operates on values within a state with implications for biodiversity, but other factors in addition to values must be investigated to fully understand what leads to proconservation behavior.  相似文献   
827.
ABSTRACT: Bivariate and trivariate distributions have been derived from the logistic model for the multivariate extreme value distribution. Marginals in the models are extreme value type I distributions for two-component mixture variables (mixed Gumbel distribution). This paper is a continuation of the previous works on multivariate distribution in hydrology. Interest is focused on the analysis of floods which are generated by different types of storms. The construction of their corresponding probability distributions and density functions are described. In order to obtain the parameters of such a bivariate or trivariate distribution, a generalized maximum likelihood estimation procedure is proposed to allow for the cases of samples with different lengths of record. A region in Northern Mexico with 42 gauging stations, grouped into two homogeneous regions, has been selected to apply the models. Results produced by the multivariate distributions have been compared with those obtained by the Normal, log-Normal-2, log-Normal-3, Gamma-2, Gamma-3, log-Pearson-3, Gumbel, TCEV and General Extreme Value distributions. Goodness of fit is measured by the criterion of standard error of fit. Results suggest that the proposed models are a suitable option to be considered when performing flood frequency analysis.  相似文献   
828.
Abstract:  Biodiversity indicator species are needed for classifying biotopes and sites for conservation, and a number of methods have been developed for determining indicator species for this purpose. Nevertheless, in addition to site classification, there is sometimes a need to define an indicator species that indicates the occurrence of another species. For example, when a species of interest (target species) is difficult to detect or identify, a reliable indicator species can function as a tool that saves time and money. We derived a method that provides a quantitative measure of the indicator power (IP) of an indicator species for the target species or any species assemblage. We calculated the measure of IP from a presence–absence matrix that covered several sites. The method provided a list of indicator species, the presence of which reliably indicated the presence of another species (e.g., a threatened or rare species in a given area). The IP of the species was highest when the number of shared occurrences between the indicator species and the target species was high and, simultaneously, when the indicator species and the target species occurred separately in only a few cases. The IP was also positively influenced by the number of sites with no occurrences of either the indicator or the target species. Our method can also be used to quantify different types of species occurrence indications. We refer to these types as presence–presence, presence–absence, absence–presence, and absence–absence indications. To clarify the use of the method, we examined the situation with red-listed polypores in White-backed Woodpecker (Dendrocopos leucotos) habitats in Fennoscandia and found some suitable indicator species. Our method provides a new, objective way to evaluate the IP of an indicator species.  相似文献   
829.
罗尔斯顿把价值评价关系引入了自然系统,想从自然的创造性关系引出价值的关系,并把价值最重要的属性看作是创造性,因而,他也就偏离了主体设定的价值取向,把价值的生成看成是自然本身的事情了。  相似文献   
830.
重要基础设施脆弱性评价模型及其应用   总被引:2,自引:2,他引:0  
将重要基础设施脆弱性定义为威胁情景、保护作用和重要性的函数,并提出一种可定量化的重要基础设施脆弱性评价模型。模型结合系统理论知识分解系统,选取威慑、延迟、检测、响应4个评价因子评估系统各环节。模型由相关领域专家确定系统各环节权重以及为评价因子赋值,应用线性加权聚集模拟技术,综合评价因子信息;依据系统状况,建立系统各环节价值函数,运行模型得到脆弱性概率密度函数,以数学期望值表示系统脆弱性总值。并将模型应用于天津市部分供水系统,不仅得到系统各环节的实际评价值,而且可得整个供水系统脆弱性评价值,为更好地改进天津市供水系统各环节的安全运行提供了科学依据。  相似文献   
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