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排序方式: 共有361条查询结果,搜索用时 805 毫秒
151.
152.
采用生物膜与悬浮生长强化处理工艺,提高了高负荷生物滤池后续活性污泥的抗冲击负荷和可生化性.综合了生物滤池与活性污泥法各自的优越性,提高了处理效果. 相似文献
153.
Vinyl acetate monomer (VAM) is widely used as a chemical intermediate producing a variety of copolymer products. Besides, VAM has the tendency to readily decompose into free radicals and ions that initiates the self-sustaining polymerization reaction. The non-isothermal experiments of VAM were performed using differential scanning calorimetry (DSC), and the calculations of the kinetic parameters from temperature-programmed DSC curves have been evaluated by the isoconversional method. The thermal analysis of VAM was proceeded using the advanced thermal analysis software (AKTS) to figure out the time to maximum rate (TMR) and self-accelerating decomposition temperature (SADT) for a proactive safety design of VAM. Subsequently, the kinetic model is used to predict the potential thermal runaway in the VAM-PVAc polymerizing process. 相似文献
154.
为了解当岩体具有急倾斜构造和水平裂隙发育时,由该岩体形成顺层和逆层边坡情况下,不同坡角对该边坡稳定性的影响,使用基于颗粒流理论的PFC3D进行了模拟。利用PFC3D中的JSET和Bonds模拟了非连续性和连续性的岩体构造形式。构建了坡角为40°、50°、60°、70°和80°的顺层和逆层边坡,并对边坡稳定性进行了模拟。模拟结果表明,岩层的重力作用在逆层时有利于岩体外倾,顺层时抑制外倾。相同坡角时顺层较逆层更为稳定。大变形裂隙区的出现位置与岩体构造有很大关系。提出的修建边坡坡角建议为顺层时坡角不应大于60°,逆层时坡角不应大于50°。 相似文献
155.
Despite laboratory experiments that have been performed to study internal heavy metal release, our understanding of how heavy metals release in shallow eutrophic lakes remains limited for lacking in-situ evidence. This study used automatic environmental sensors and a water sampling system to conduct high-frequency in-situ observations (1-hr intervals) of water environmental variables and to collect water samples (3-hr intervals), with which to examine the release of internal heavy metals in Lake Taihu, China. Under conditions of disturbance by strong northerly winds, sediment resuspension in both the estuary area and the lake center caused particulate heavy metal resuspension. However, the patterns of concentrations of dissolved heavy metals in these two areas were complex. The concentrations of dissolved Se and Mo increased in both areas, indicating that release of internal dissolved Se and Mo is triggered by sediment resuspension. The concentrations of dissolved Ni, Zn, As, Mn, Cu, V, and Co tended to increase in the estuary area but decrease in the lake center. The different trends between these two areas were controlled by pH and cyanobacteria, which are related to eutrophication. During the strong northerly winds, the decrease in concentrations of dissolved heavy metals in the lake center was attributable primarily to absorption by the increased suspended solids, and to growth-related assimilation or surface adsorption by the increased cyanobacteria. The findings of this study suggest that, short-term changes of environmental conditions are very important in relation to reliable monitoring and risk assessment of heavy metals in shallow eutrophic lakes. 相似文献
156.
欧洲红豆杉细胞培养的研究 总被引:3,自引:0,他引:3
从欧洲红豆杉(Taxusbaccata)的嫩茎及什叶诱导出愈伤组织,并对之进行了愈伤组织培养及细胞悬浮培养研究;利用HPLC方法测定了培养物合成紫杉醇的能力.探索了提高培养细胞生长率及紫杉醇含量的一些措施.结果表明,欧洲红豆杉愈伤组织及悬浮培养细胞的生长速率已分别达到0.27g·L-1·d-1和0.35g·L-1·d-1,紫杉醇含量分别为0.0031%和0.017%。 相似文献
157.
石油在水中悬浮物上的吸附研究 总被引:7,自引:0,他引:7
采用青岛大沽河河口的泥沙为吸附剂,0号柴油和32号柴油为吸附质,以此来研究石油在水中悬浮物上的吸附特性。首先分析了水中分散油的浓度分布特点,提出了计算平衡浓度下吸附量的公式,然后分析了吸附动力学过程,研究了石油在不同温度、含沙浓度、盐度条件下的吸附特性以及不同油种对吸附特性的影响,并探讨了吸附机理,研究了石油在不同温度、含沙浓度、盐度条件下的吸附特性以及不同油种对吸附特性的影响,并探讨了吸附机理。本文的研究为揭示水环境中石油污染机理、评价溢油对水环境的影响作了有意义的探讨。 相似文献
158.
公交行业金属清洗废液处理工艺研究 总被引:3,自引:0,他引:3
清洗废液中含有各种形态的油份,污泥悬浮物及表面活性剂。经预处理及一级处理后,COD总去除率90%,浊度,油份总去除率95%以上,清洗液可循环回用。 相似文献
159.
Padmanathan Kathirgamanathan Robert McKibbin Robert I. McLachlan 《Environmental Modeling and Assessment》2004,9(1):33-42
The goal is to build up an inverse model capable of finding the release history of atmospheric pollution by using measured gas concentration data at just one location on the ground and identify the factors which affects the accuracy of the model predictions. The problem involves a non-steady point source of pollution at a known location in the atmosphere. This problem of finding the release rate is an ill-posed inverse problem and its solution is extremely sensitive to errors in the measurement data. Special regularisation methods, which stabilise the process of the solution, must be used to solve the problem. The method described in this paper is based on linear least-squares regression and Tikhonov regularisation, coupled with the solution of an advection-diffusion equation for a non-steady point source. The accuracy of the method is examined by imposing normally-distributed relative noise into the concentration data generated by the forward model as well as some real experimental data. 相似文献
160.