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151.
W. Harry Doyle 《Journal of the American Water Resources Association》1981,17(2):225-232
ABSTRACT: Urban storm water data from four catchments near Miami, Florida, were collected and compiled by the U.S. Geological Survey and were used for testing the applicability of deterministic modeling for characterizing storm water flows from small land use areas. The four sites were:
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152.
国外几次震后火灾的对比研究 总被引:1,自引:0,他引:1
震后起火是国外几次大的普遍现象。本文通过对国外几次震后火灾的对比分析,归纳总结了引发震后火灾的主要因素及震后火灾的特点。震后火灾与生命线系统的破坏有密切关系,本文从震后火灾的机理出发,提出了用事件树模型预测供气供电系统引发震后火灾的方法。 相似文献
153.
ABSTRACT: Existing discrete, linear rainfall-runoff models generally require the effective rainfall of a given storm as the input for computing the runoff hydrograph. This paper proposes a method for estimating, simultaneously, the optimal values of model parameters and the rainfall losses frem the measured rainfall hyetograph and the runoff hydrograph. The method involves an ARMA model for the rainfall-runoff process and a nonlinear iterative technique. The number of model parameters to be estimated for the ARMA model is much less than the unit hydrograph model. Applications of the model to three different watersheds show that the computed runoff hydrographs agree well with the measurements. 相似文献
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157.
HUANG Jin-liang DU Peng-fei AO Chi-tan LEI Mui-heong ZHAO Dong-quan HO Man-him WANG Zhi-shi 《环境科学学报(英文版)》2007,19(2):148-152
Characteristics of surface runoff from a 0.14-km^2 urban catchment with separated sewer in Macau was investigated. Water quality measurements of surface runoff were carried out on five rainfall events during the period of August to November, 2005. Water quality parameters such as pH, turbidity, TSS, COD, TN, Zn, Pb, and Cu were analyzed. The results show that TN and COD are the major pollutants from surface runoff with mean concentration of 8.5 and 201.4 mg/L, both over 4-fold higher compared to the Class V surface water quality standard developed by China SEPA. Event mean concentration (EMC) for major pollutants showed considerable variations between rainfall events. The largest rainfall event with the longest length of antecedent dry weather period (ADWP) produced the highest EMC of TN, TSS and COD. From the pollutographs analysis, the peak concentration of TN precedes the peak runoff flow rate for all three rainfall events. The tendency of the concentration of TSS, turbidity and COD changing with runoff flow varies between rainfall events. The relationship between TSS and other parameters were analyzed to evaluate the efficiency of the physical treatment process to control the surface runoff in the urban catchment. Based on the correlation of parameters with TSS, high treatment efficiency of TSS, TN and COD was expected. The most significant event in term of first flush is the one with the strongest rainfall intensity and longest length of ADWP. TN always showed first flush phenomenon in all three rainfall events, which suggested that the surface runoff in the early stage of surface runoff should be dealt with for controlling TN losses during rainfall events. 相似文献
158.
为了减少重大突发事件造成的损失,以"4.20"雅安地震为例,分析了重大突发事件具有突发性强、影响范围大且后果严重、救援紧迫性强、参与主体多元化等特点。与汶川地震比较,雅安地震在救灾反应速度、救灾手段和救灾效率3个方面有比较大的进步,但也存在管理混乱、信息混乱、角色混乱等问题。在此基础上,阐述了面对重大突发事件时值得人们思考的问题,为类似事件应急管理提供参考与思路。 相似文献
159.
网络事件空间聚类分析可发现供水、排水、燃气、电力等生命线工程爆管、漏损事件的高发区域。生命线工程事件由网络边约束,可抽象为网络事件。若不考虑网络拓扑关系,将产生网络事件空间聚类结果与实际分类不符的问题。基于事件网络距离,提出了一种通用的网络事件空间聚类方法,给出了核心概念的形式化定义以及算法描述,可广泛应用于生命线工程事件高发区域的发现,具有较强的实用性。并结合供水管网生命线工程爆管事件高发区域分析实例,给出算法参数的确定原则和范围,验证了所提出的算法的有效性。 相似文献
160.
Rare events often result in large impacts and are hard to predict. Risk analysis of such events is a challenging task because there are few directly relevant data to form a basis for probabilistic risk assessment. Due to the scarcity of data, the probability estimation of a rare event often uses precursor data. Precursor-based methods have been widely used in probability estimation of rare events. However, few attempts have been made to estimate consequences of rare events using their precursors. This paper proposes a holistic precursor-based risk assessment framework for rare events. The Hierarchical Bayesian Approach (HBA) using hyper-priors to represent prior parameters is applied to probability estimation in the proposed framework. Accident precursor data are utilized from an information theory perspective to seek the most informative precursor upon which the consequence of a rare event is estimated. Combining the estimated probability and consequence gives a reasonable assessment of risk. The assessed risk is updated as new information becomes available to produce a dynamic risk profile. The applicability of the methodology is tested through a case study of an offshore blowout accident. The proposed framework provides a rational way to develop the dynamic risk profile of a rare event for its prevention and control. 相似文献