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961.
The environmental situation in Ghana is characterized by desertification, land degradation, deforestation, soil erosion, and
inadequate water supply in the northern regions of the country. The population as a whole is growing at a rate of 3% per annum,
with even greater urban growth rates, due to rural out-migration. Large parts of the coastal zone in the south are rapidly
developing to become one large suburbanized area. Water quality is particularly threatened in the urban and industrialized
areas, which are mainly located in the southern part of the country. The coastal lagoons and coastal waters are moderately
to heavily polluted. Erosion extends along the whole Ghanaian coast with excesses, for example, in the Keta area, where during
the last century over 90% of the original buildings have been washed awayby the sea. The obvious environmental consequences
of the mining sector are illustrative of the environmental threats caused by a fast growing industry and industrializing agriculture,
in a country where environmental policy is only in its formative years. Desertification, food insecurity and coastal erosion
all contribute to an increasing number of environmental refugees.
Environmental policy in Ghana is a post-Rio phenomenon. Environmental laws, a Ministry of Environment, Science and Technology,
an advisory National Committee for the Implementation of Agenda 21, and a fully mandated environmental administration have
been established. This administration advocates a progressive attitude towards environmental legislation and points out the
specific utility of economic and legal instruments in environmental management in this relatively fast developing country.
The choice of instruments for environmental management is increasingly influenced by the specific state of African environmental
and technological capacity and by a call for the recognition of the role of traditional customs in nature conservation. This
African perspective on environmental management is further intensified by an unmet need for regional, transboundary cooperation
in the West African subcontinent. This specific West African context calls for an elaboration of an effective capacity-building
program for environmental management in the area. 相似文献
962.
963.
焦国太 《中国安全科学学报》1999,9(5):74-77
安全性与作用可靠性是引信的两项重要技术指标。引信的工作过程和工作环境比较特殊,不同于一般的机电产品。在一般机电产品的安全可靠性建模过程中,环境因素不被考虑,但对于引信而言,其可靠性与环境力却有着密切关系。笔者根据引信工作的特殊性,对环境力及其作用时间的安全可靠度及作用可靠度进行了计算。 相似文献
964.
Thomas Hruby 《Environmental management》1999,23(1):75-85
/ Many methods have been developed over the last two decades to provide information about wetland functions, but there has been little discussion of the models and algorithms used. Methods for generating information about wetlands were analyzed to understand their similarities, differences, and the type of information provided. Methods can first be grouped by the type of information they provide-classifications, characterizations, ratings, assessments, and evaluations. Methods that characterize, rate, or assess wetlands may generate information using one of two conceptual approaches-logic and mechanistic. Most methods that generate a numeric assessment of performance or value of wetland functions rely on the mechanistic approach to constructing models. Rapid assessment methods based on mechanistic models, however, do not assess the rates or dynamics of ecological processes occurring in wetlands. Rather, they provide a clear and concise way of organizing our current, and often subjective, knowledge about wetland functions. This is one limitation of current methods that is often misunderstood both by wetland managers and the scientific community. The advantages and limitations of the assumptions and the computational elements inherent in these approaches are discussed to provide wetland managers and regulators a better understanding of the information they are using. KEY WORDS: Wetlands; Functions; Assessment; Models; Methods 相似文献
965.
乌鲁木齐市市民环境意识万人问卷调查报告 总被引:3,自引:0,他引:3
为贯彻全国和自治区第4次环保会议精神,了解和提高全市各族群众的环境意识,使环境保护基本国策深入人心,乌鲁木齐市环保局在1998年“六·五”世界环境日之际开展了以“关心环境保护,共建美丽首府”为主题的市民环境意识万人问卷活动。由全市7区1县及2个开发区环保局(站)协助,分别在政府机关、厂矿、学校、街头、摊点进行发放问卷活动。调查结果初步摸清了乌鲁木齐市在环境宣传教育中所取得的成效和存在的问题,为今后更好地加强环境宣传教育,普及环境科学知识,提高社会各界环境意识提供了参考信息。 相似文献
966.
Alan F. Hamlet Dennis P. Lettenmaier 《Journal of the American Water Resources Association》1999,35(6):1597-1623
ABSTRACT: As part of the National Assessment of Climate Change, the implications of future climate predictions derived from four global climate models (GCMs) were used to evaluate possible future changes to Pacific Northwest climate, the surface water response of the Columbia River basin, and the ability of the Columbia River reservoir system to meet regional water resources objectives. Two representative GCM simulations from the Hadley Centre (HC) and Max Planck Institute (MPI) were selected from a group of GCM simulations made available via the National Assessment for climate change. From these simulations, quasi-stationary, decadal mean temperature and precipitation changes were used to perturb historical records of precipitation and temperature data to create inferred conditions for 2025, 2045, and 2095. These perturbed records, which represent future climate in the experiments, were used to drive a macro-scale hydrology model of the Columbia River at 1/8 degree resolution. The altered streamflows simulated for each scenario were, in turn, used to drive a reservoir model, from which the ability of the system to meet water resources objectives was determined relative to a simulated hydrologic base case (current climate). Although the two GCM simulations showed somewhat different seasonal patterns for temperature change, in general the simulations show reasonably consistent basin average increases in temperature of about 1.8–2.1°C for 2025, and about 2.3–2.9°C for 2045. The HC simulations predict an annual average temperature increase of about 4.5°C for 2095. Changes in basin averaged winter precipitation range from -1 percent to + 20 percent for the HC and MPI scenarios, and summer precipitation is also variously affected. These changes in climate result in significant increases in winter runoff volumes due to increased winter precipitation and warmer winter temperatures, with resulting reductions in snowpack. Average March 1 basin average snow water equivalents are 75 to 85 percent of the base case for 2025, and 55 to 65 percent of the base case by 2045. By 2045 the reduced snowpack and earlier snow melt, coupled with higher evapotranspiration in early summer, would lead to earlier spring peak flows and reduced runoff volumes from April-September ranging from about 75 percent to 90 percent of the base case. Annual runoff volumes range from 85 percent to 110 percent of the base case in the simulations for 2045. These changes in streamflow create increased competition for water during the spring, summer, and early fall between non-firm energy production, irrigation, instream flow, and recreation. Flood control effectiveness is moderately reduced for most of the scenarios examined, and desirable navigation conditions on the Snake are generally enhanced or unchanged. Current levels of winter-dominated firm energy production are only significantly impacted for the MPI 2045 simulations. 相似文献
967.
968.
石油化工项目环境风险评价实例分析 总被引:6,自引:0,他引:6
环境风险评价是石油化工项目环境影响评价的一项重要内容。笔者以某拟建沥青厂为例,利用有关事故统计资料类比分析和世界银行推荐的爆炸危害关系式,对石油化工项目环境风险半定量评价进行了初步探讨。结果表明,该厂发生泄漏事故不会波及外环境,爆炸事故将造成厂区严重破坏并对局地大气环境产生一定影响。 相似文献
969.
提出将单项污染物测值反映的信息量表示为相对重要性和将单项污染物的相对重要性综合为多项污染物的综合相对重要性的计算公式。根据测点信息的综合相对重要性,再用主成分子集合选择法优化选点。该方法不仅减少了计算量,也易于确定多项污染物的综合优化点。该方法用于贵阳市大气环境测点优选出的测点能反映该市的环境质量。 相似文献
970.