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391.
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To analyze China’s actual urbanization level, we iden- tified two statistical approaches: using the population living within the administrative boundaries (administrative-based method) and within the urbanized or built-up areas (infrastructure-based method) of cities and towns as urban population. To illustrate the two approaches and the associated problems, we used data for Tangshan City as a case study. The estimates on the administrative-based method were unreliable and the infrastructurebased method pro... 相似文献
393.
A Radon Potential Map as well as a mean indoor Radon Concentration Map is available from the Austrian National Radon Project (1992-2002). These maps are based on the average Radon Potential/Concentration within every municipality and they sort municipalities into three radon ‘risk’ classes. This is a convenient way for the administration, but it does not describe the real radon risk distribution within a municipality because of the often inhomogeneous geological situation. Therefore, a combination of indoor radon data with all relevant parameters such as house type, storey and ventilation rates along with geological information should be used to improve the existing radon maps. The method, described here, uses Bayes' theory to combine the Radon Potential derived from indoor radon measurements with information from geology. The existing Radon Potential Map was improved by using available soil gas radon data at certain geological units and extrapolated transfer factors. The modifications of the map are shown and several problems arising with the application of this technique are discussed. 相似文献
394.
Charles L. Dow 《Journal of the American Water Resources Association》1999,35(2):349-362
ABSTRACT: An established trend analysis methodology was applied to the problem of identifying and quantifying stream base flow impacts from water withdrawals and water loss through interbasin transfers. Impacts were simulated using base flow values selected from two U.S. Geological Survey (USGS) continuous record streamflow sites located within the Pinelands of southern New Jersey. Study site base flows were regressed against index site base flows with monotonic and step trend tests applied to the residuals from the regression model. The smallest, significantly detectable (α= 0.10) percentage reduction within a given simulation was used as an estimate of the sensitivity of a trend test. Evaluation of the trend analysis methodology led to the following practical considerations regarding trend test sensitivity. The proportion of study site base flow variability explained by index site base flows should be maximized, while at the same time minimizing positive, first-order autocorrelation in the regression residuals. Given the importance of detecting autocorrelation, missing values should be avoided or minimized. The quarterly (three-month) interval reduced the magnitude of autocorrelation relative to a shorter two-month sampling interval. Sensitivity appeared to improve when equalizing the number of values before and after a base flow impact(s) while seasonally biased sampling appeared to reduce sensitivity. Based primarily on past trend detection studies, nonparametric tests were deemed a better choice over their parametric counterparts, due to the lack of stringent data distributional requirements coupled with little or no loss of power even when applied to normally distributed data. 相似文献
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环境中的放射性数据处理是一项重要的基础工作,在辐射环境常规监测中放射性数据运用科学的方法进行处理,避免数据处理工作中的主观性、随意性。本文例举说明如何运用数理统计的方法进行放射性数据的分析评判。 相似文献
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398.
危险化学品公路运输事故新特点及对策研究 总被引:5,自引:2,他引:3
统计分析了2008年1月~2010年5月我国发生的485起危险化学品公路运输事故。从事故发生的原因、事故涉及的化学品、事故造成的危害、事故发生的月份分布及年份变化等几个方面,分析了近年来危险化学品公路运输事故的新特点及变化规律。经统计分析,道路交通事故是引发危险化学品运输事故的主要原因之一;侧翻是危险化学品车辆最容易发生的道路交通事故;而随着我国高速公路的迅猛发展,追尾造成的危险化学品运输事故数量呈上升趋势;危险化学品公路运输过程中易燃液体事故起数最多,爆炸品和毒性物质事故造成的人员伤亡最严重;春节前后取代夏季,成为近两年危险化学品运输事故高发期。针对这些特点,对我国危险化学品公路运输安全管理与监控提出了建议。 相似文献
399.
Urban disaster recovery: a measurement framework and its application to the 1995 Kobe earthquake 总被引:1,自引:0,他引:1
Stephanie E. Chang 《Disasters》2010,34(2):303-327
This paper provides a framework for assessing empirical patterns of urban disaster recovery through the use of statistical indicators. Such a framework is needed to develop systematic knowledge on how cities recover from disasters. The proposed framework addresses such issues as defining recovery, filtering out exogenous influences unrelated to the disaster, and making comparisons across disparate areas or events. It is applied to document how Kobe City, Japan, recovered from the catastrophic 1995 earthquake. Findings indicate that while aggregate population regained pre‐disaster levels in ten years, population had shifted away from the older urban core. Economic recovery was characterised by a three to four year temporary boost in reconstruction activities, followed by settlement at a level some ten per cent below pre‐disaster levels. Other long‐term effects included substantial losses of port activity and sectoral shifts toward services and large businesses. These patterns of change and disparity generally accelerated pre‐disaster trends. 相似文献
400.