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排序方式: 共有1318条查询结果,搜索用时 906 毫秒
981.
采用气浮-动态微电解—水解酸化—接触氧化工艺,对无锡某化工总厂丙烯酸废水原工艺和设备进行了改造,经过调试运行,监测结果表明,进水COD为6 000~10 000 mg/L时,处理出水COD小于60 mg/L。出水达到太湖地区重点工业行业主要水污染物排放标准。  相似文献   
982.
对溇水上游河湾岩溶渗漏研究中,在湘鄂交界的溇水河谷,发现了大型古滑坡体和堰塞湖沉积粘土层并对其进行了研究。对古滑坡体和堰塞湖作了简要介绍,对一些主要问题进行初步讨论和分析。古滑坡体约2000×104 m3,进入河道长度大于 1000 m;湖相沉积层厚度大于48 m,最大出露高程2841 m,根据14C测试,古堰塞湖形成于 10760±130~16880±250 a BP。通过分析认为堰塞湖水位大于285 m,堰塞湖沉积粘土层中出露的高硫酸盐地下水与当时沉积环境和粘土层本身无直接联系,沿河两岸粘土层产状变化可能与再次滑坡有关联;该研究成果对当前水电工程建设和研究溇水河流发育史、现代江河灾难性地质灾害的形成演化具有一定参考价值  相似文献   
983.
In semi-arid valleys of southwestern China, seasonal shortage of water is the major contributing factor to low and unstable crop yield. Harvesting of both rainwater and brooklets water in the semi-arid valleys of Ningnan county of Sichuan Province has brought about considerable economic and environmental change. Brooklet water is collected throughout the year but mainly during the rainy season in a series of ponds while rainwater is harvested in underground tanks constructed on road side or land boundaries with only a small opening above ground to save limited cropland. Increased water availability has promoted cultivation of sugarcane, tobacco, and mulberry, and increased per unit area yield of food crops. Sericulture, sugarcane and tobacco have become three important sources of farmers' income. The water harvesting has contributed considerably to increased rural income, poverty reduction, reduced soil erosion and improvement in overall environment. Government has played a key role in planning and implementation of water harvesting programmes. Financial support of government and clear ownership of water harvesting facilities are critical for the success of the programme. Application of similar water harvesting techniques in other areas with similar biophysical conditions would contribute to enhancing the rural economy and alleviating poverty.  相似文献   
984.
Based on the extraction method presented by Smith et al. (2008), this paper proposes an improved method, the multi-emission/flush regression method, to simultaneously determine the initial emittable concentration and the partition coefficient. Compared to the extraction method, the proposed method has the following advantages: (1) it is unnecessary for the target volatile organic compounds (VOCs) to emit completely from the material, thus greatly reducing experimental time; (2) it provides a simpler way to obtain the partition coefficients of VOCs for tested materials and can avoid the measurement uncertainties at low VOC concentrations which often occur during the last few cycles of the extraction method; (3) it does not require grinding the building material into powders thus making this method more convenient to use. Comparisons were made between the initial emittable VOC concentrations determined by the original extraction method and the proposed method. Results show good agreements between these two methods. To further validate the proposed method, the type of static chamber developed by Wang et al. (2006) was used to conduct the experiment for a type of medium density board, and formaldehyde was selected as the target compound. Based on the initial emittable concentration and partition coefficient obtained using the proposed method, and the diffusion coefficient obtained by the mercury intruding porosimetry, the chamber formaldehyde concentration was predicted and compared with the experimental measurements. Results show that the predicted chamber VOC concentration using the measured parameters agree well with the experimental data.  相似文献   
985.
The geological storage of CO2 in deep saline formations is increasing seen as a viable strategy to reduce the release of greenhouse gases to the atmosphere. There are numerous sedimentary basins in China, in which a number of suitable CO2 geologic reservoirs are potentially available. To identify the multi-phase processes, geochemical changes and mineral alteration, and CO2 trapping mechanisms after CO2 injection, reactive geochemical transport simulations using a simple 2D model were performed. Mineralogical composition and water chemistry from a deep saline formation of Songliao Basin were used. Results indicate that different storage forms of CO2 vary with time. In the CO2 injection period, a large amount of CO2 remains as a free supercritical phase (gas trapping), and the amount dissolved in the formation water (solubility trapping) gradually increases. Later, gas trapping decrease, solubility trapping increases significantly due to the migration and diffusion of CO2 plume and the convective mixing between CO2-saturated water and unsaturated water, and the amount trapped by carbonate minerals increases gradually with time. The residual CO2 gas keeps dissolving into groundwater and precipitating carbonate minerals. For the Songliao Basin sandstone, variations in the reaction rate and abundance of chlorite, and plagioclase composition affect significantly the estimates of mineral alteration and CO2 storage in different trapping mechanisms. The effect of vertical permeability and residual gas saturation on the overall storage is smaller compared to the geochemical factors. However, they can affect the spatial distribution of the injected CO2 in the formations. The CO2 mineral trapping capacity could be in the order of 10 kg/m3 medium for the Songliao Basin sandstone, and may be higher depending on the composition of primary aluminosilicate minerals especially the content of Ca, Mg, and Fe.  相似文献   
986.
基于ArcSDE的地震紧急救援数据库建设   总被引:4,自引:0,他引:4  
提出了建设地震紧急救援数据库的必要性,阐述了地震紧急救援数据库的建设目标,分析了ArcSDE的基础原理,以四川省紧急救援队为例,介绍了利用ArcSDE技术构建地震紧急数据库的建设方法。  相似文献   
987.
988.
为了研究使用随机化Pushover方法进行RC框架结构整体抗震可靠度计算过程中相关参数的适应性,使用Matlab调用SAP2000编制出基于随机化Pushover的结构整体抗震可靠度程序,以一榀11层RC框架结构为例,通过该程序统计出不同参数下结构最大层间位移角的分布情况及整体失效概率,并以大样本实际地震波进行时程分析所统计出的相应结果为基准进行对比。结果表明,在常规参数设置下随机化Pushover方法统计出的最大层间位移角分布情况和结构整体失效概率与大样本时程分析结果有较大差异,然后提出了一种修正方式,有效地减小了两者的差异,并以某算例验证了该修正方式的适用性。  相似文献   
989.
石墨粉末润湿特性及其表面自由能的研究   总被引:1,自引:0,他引:1  
利用毛细上升法测定了去离子水对石墨粉末的接触角,分析温度对石墨粉末润湿性的影响,并测算了石墨粉末的表面自由能,对将石墨用作净水滤料有指导作用.在20~40℃温度范围内接触角变化不大,平均为84.11°.其主要原因是表面张力σ和黏度η随温度变化对接触角的影响相反,综合作用结果导致接触角随温度变化不大.石墨粉末表面色散自由能为21.8 mJ·m-2,极性自由能为1.8 mJ·m-2,总的表面自由能约为23.6 mJ·m-2,以色散自由能为主.这是去离子水能够湿润石墨粉末,但湿润性相对较差的一个原因.可知极性流体对石墨粉末的润湿性比较差.  相似文献   
990.
木材胶粘剂生产中的污染及防治   总被引:3,自引:0,他引:3  
熊伟  王小妹  王占文 《化工环保》1999,19(4):213-215
阐述了木材胶粘剂-脲醛树脂胶粘剂(UF),密胺甲醛树脂胶粘剂(MF),酚醛树脂胶粘剂(PF)生产过程中产生的废气,釜垢及碱洗废液的污染,提出了从工艺上改善排放条件及治理的方法,同时提出了控制产品中游离甲醛的方法。  相似文献   
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