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排序方式: 共有1370条查询结果,搜索用时 15 毫秒
1.
以调质高炉渣为原料在实验室进行了四辊离心法制备矿渣棉实验.研究高炉渣滴落温度、粘度、离心辊径及转速等工艺参数对矿渣棉成纤效果的影响规律.结果表明,高炉渣滴落温度应控制在1 290~1 420℃之间,高炉渣粘度在1~3 Pa.s;四辊直径分别为1# 213 mm、2# 295 mm、3# 295 mm和4# 295 mm时,转速控制在1# 2 707~3 000 r/min、2# 3 093~4 000 r/min、3# 4 350~4 500 r/min和4# 5 000~5 800 r/min,成纤率较高,成纤效果良好. 相似文献
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地震应急是地震救援工作的重要组成部分,科学的制订地震应急救援预案是做好应急工作的前提.本文分析了目前我国地震应急预案体系的现状,总结了地震应急预案体系中存在的问题,对于丰富和完善地震应急预案体系,使政府及社会高效、有序地做好应急响应,减少人员伤亡和财产损失具有重要的现实意义. 相似文献
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Xiaolong Li Congcong Ding Jiali Liao Liang Du Qun Sun Jijun Yang Yuanyou Yang Dong Zhang Jun Tang Ning Liu 《环境科学学报(英文版)》2017,29(3):9-15
The microbial reduction of U(VI) by Bacillus sp. dwc-2, isolated from soil in Southwest China, was explored using transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge spectroscopy (XANES). Our studies indicated that approximately 16.0% of U(VI) at an initial concentration of 100 mg/L uranium nitrate could be reduced by Bacillus sp. dwc-2 at pH 8.2 under anaerobic conditions at room temperature. Additionally, natural organic matter (NOM) played an important role in enhancing the bioreduction of U(VI) by Bacillus sp. dwc-2. XPS results demonstrated that the uranium presented mixed valence states (U(VI) and U(IV)) after bioreduction, which was subsequently confirmed by XANES. Furthermore, the TEM and high resolution transmission electron microscopy (HRTEM) analysis suggested that the reduced uranium was bioaccumulated mainly within the cell and as a crystalline structure on the cell wall. These observations implied that the reduction of uranium may have a significant effect on its fate in the soil environment in which these bacterial strains occur. 相似文献
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Jun Zhang Ding Gao Tong-Bin Chen Guo-Di Zheng Jun Chen Chuang Ma Song-Lin Guo Wei Du 《Waste management (New York, N.Y.)》2010,30(10):1931-1938
To simulate the substrate degradation kinetics of the composting process, this paper develops a mathematical model with a first-order reaction assumption and heat/mass balance equations. A pilot-scale composting test with a mixture of sewage sludge and wheat straw was conducted in an insulated reactor. The BVS (biodegradable volatile solids) degradation process, matrix mass, MC (moisture content), DM (dry matter) and VS (volatile solid) were simulated numerically by the model and experimental data. The numerical simulation offered a method for simulating k (the first-order rate constant) and estimating k20 (the first-order rate constant at 20 °C). After comparison with experimental values, the relative error of the simulation value of the mass of the compost at maturity was 0.22%, MC 2.9%, DM 4.9% and VS 5.2%, which mean that the simulation is a good fit. The k of sewage sludge was simulated, and k20, k20s (first-order rate coefficient of slow fraction of BVS at 20 °C) of the sewage sludge were estimated as 0.082 and 0.015 d?1, respectively. 相似文献
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应用时间破裂分析方程中表征地震距释放程度的m值,选取不同空间尺度进行时空扫描研究,得到震前1年以每2个月为时间间隔的空间m值随时间变化的分布图像,运用不同参数设置计算了地震前Benioff累积应变释放特征。通过对比这些变化找出研究区内m值空间分布搜索主震破裂点扫描效果较好的参数模型,尝试性地给出了"矩释放程度空间扫描"方法应用于地震预测的经验指标。并结合与矩加速释放具有相同物理机制的加卸载响应比(Load/Unload Response Ratio)方法进行综合分析,利用这两种方法对地震进行中短期预测,达到两种方法互相检验、相互辅助的目的。考虑到本文仅对6个震例进行研究,无法给出具有统计显著性的结论,所以仍需结合其他方法进行点、线、面的综合分析。 相似文献
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Long-lasting expansion of haze pollution in China has already presented a stern challenge to regional joint prevention and control. There is an urgent need to enlarge and reconstruct the coverage of joint prevention and control of air pollution in key area. Air quality models can identify and quantify the regional contribution of haze pollution and its key components with the help of numerical simulation, but it is difficult to be applied to larger spatial scale due to the complexity of model parameters. The time series analysis can recognize the existence of spatial interaction of haze pollution between cities, but it has not yet been used to further identify the spatial sources of haze pollution in large scale. Using econometric framework of time series analysis, this paper developed a new approach to perform spatial source apportionment. We applied this approach to calculate the contribution from spatial sources of haze pollution in China, using the monitoring data of particulate matter (PM2.5) across 161 Chinese cities. This approach overcame the limitation of numerical simulation that the model complexity increases at excess with the expansion of sample range, and could effectively deal with severe large-scale haze episodes. 相似文献
10.
秦皇岛地热能梯级利用状况与前景分析 总被引:2,自引:0,他引:2
在对秦皇岛地热能资源现状和开发利用调查的基础上,对秦皇岛地区的地热资源分布特征进行了分类,通过对相应的地热资源利用现状进行调查,掌握了地热能利用的现状以及存在的种种问题和不足。为了更加合理高效地利用地热能资源,进行开发利用前景分析,制定了地热能综合梯级利用的规划建议。 相似文献