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951.
The accumulation and species of mercury (Hg) in mosses and lichens collected from high-altitude Tibetan Plateau were studied. The altitudes of the sampling sites spanned from 1983 to 5147 m, and a total of 130 mosses and 52 lichens were analyzed. The total mercury (THg) contents in mosses and lichens were in the ranges of 13.1–273.0 and 20.2–345.9 ng/g, respectively. The average ratios of methylmercury (MeHg) in THg in mosses and lichens were 2.4 % (0.3–11.1 %) and 2.7 % (0.4–9.6 %), respectively, which were higher than those values reported in other regions. The contents of THg in both mosses and lichens were not correlated with the THg in soils (p > 0.05). The lipid contents displayed a significantly positive correlation with concentrations of MeHg in mosses (r = 0.461, p < 0.01, n = 90), but not in lichens. The correlations between Hg contents in mosses and the altitudes, latitudes and longitudes of sampling sites indicated the mountain trapping and spatial deposition of Hg in the Tibetan Plateau.  相似文献   
952.
Journal of Material Cycles and Waste Management - The dry climate of the Qinghai–Tibet Plateau causes the rapid loss of moisture in composting piles, which affects dynamics of the composting...  相似文献   
953.
用黄姜皂素残渣制备活性炭   总被引:6,自引:0,他引:6  
以黄姜皂素残渣为原料,用ZnCl2为活化剂制备活性炭,研究了活化温度、活化剂浓度、液固比、活化时间对活性炭吸附性能的影响。在活化温度600℃、活化时间90min、ZnCl2质量分数40%、液固比(质量比)4条件下。制备的活性炭碘吸附值为933mg/g,苯酚吸附值为139mg/g,亚甲基蓝脱色力为150mL/g,性能优于对比的商业颗粒活性炭。  相似文献   
954.
对亚甲蓝分光光度法进行改进,用固体试剂快速测定水中的阴离子表面活性剂。在最大吸收波长652nm处,阴离子表面活性剂质量浓度为0~2.0m g/L时遵守比尔定律,表观摩尔吸光系数为1.56×104L/(m o.lcm),检出限为0.03m g/L。该方法用于自来水、河水和工业废水中阴离子表面活性剂的测定,取得了满意结果。环境水样的平均回收率为88.3%~108.0%,相对标准偏差不超过4.67%。  相似文献   
955.
煤浆洗涤法去除烟气中的SO2   总被引:2,自引:1,他引:1  
分别以高硫原煤、低硫原煤和中煤配制的煤浆作为洗涤介质,去除烟气中的SO2。反应温度高于40℃时,采用高硫原煤煤浆洗涤烟气,SO2去除率在90%以上;O2含量对SO2去除率影响不大;SO2去除率随其含量的增加而降低。低硫原煤煤浆同样可用于烟气脱硫,随温度的升高,煤浆pH的降低幅度和SO2去除率均增大,与用高硫原煤时的情况类似。中煤煤浆亦能有效去除烟气中的SO2,反应过程中煤浆pH的降低对SO2去除率的影响不大。在烟气脱硫的同时,3种煤中的黄铁矿均被不断浸出,浸出铁质量浓度随反应时间的延长和SO2去除率的增大而增加。  相似文献   
956.
城市面源污染特性及污染负荷预测模型研究   总被引:13,自引:0,他引:13  
通过分析城市面源污染的来源和污染特征,并针对城市土地利用和下垫面类型特点,建立城市面源污染预测模型,研究探讨城市降雨径流及污染负荷预测模拟和迁移规律。所建模型已成功地应用于武汉市汉阳地区城市面源污染控制技术研究,获得了满意的结果。该模型可为城市水环境规划、面源控制和管理研究提供科学手段。  相似文献   
957.
简述了全国机场的主要分类。根据近几年对各类型机场开展验收监测的实际情况及经验,指出了不同类型机场面临的主要环境问题;对机场项目验收中干线及以上规模机场飞机噪声污染、尾气排放,支线机场生态保护、中水回用、不同类型机场飞机噪声监测等问题进行了分析;就完善机场项目环保管理问题提出了建议。  相似文献   
958.
In recent years, high-molecular-weight anionic polyacrylamide (PAM) have been widely tested on a variety of soils, primarily in water erosion control. However, little information is available regarding the effectiveness of PAM on preventing soil loss from wind erosion. The research adopted room wind tunnel experiment, two kinds of soils were used which were from the agro-pastoral area of Inner Mongolia, the northwest of China, the clay content of soils were 22.0 and 13.7%, respectively. For these tests, all the treatments were performed under the condition of wind velocity of 14 m s(-1) and a blown angle of 8.75%, according to the actual situation of experimented area. The study results indicated that using PAM on the soil surface could enhance the capability of avoiding the wind erosion, at the same time, the effect of controlling wind soil erosion with 4 g m(-2) PAM was better than 2 g m(-2) PAM's. Economically, the 2 g m(-2) PAM used in soil surface can control wind erosion effectively in this region. The prophase PAM accumulated in soil could not improve the capability of avoiding the wind erosion, owing to the degradation of PAM in the soil and the continual tillage year after year. The texture of soil is a main factor influencing the capability of soil avoiding wind erosion. Soil with higher clay content has the higher capability of preventing soil from wind erosion than one with the opposite one under the together action of PAM and water.  相似文献   
959.
Factors regulating trophic status in a large subtropical reservoir, China   总被引:1,自引:0,他引:1  
We evaluated a 4-year data set (July 2003 to June 2007) to assess the trophic state and its limiting factors of Three-Gorges Reservoir (TGR), China, a large subtropical reservoir. Based on Carlson-type trophic state index (TSI)CHL, the trophic state of the system was oligotrophic (TSIS?< 40) in most months after the reservoir became operational, although both TSITP and TSITN were higher than the critical value of eutrophic state (TSIS?>?50). Using Carlson’s (1991) two-dimensional approach, deviations of the TSIS indicated that factors other than phosphorus and nitrogen limited algal growth and that nonalgal particles affected light attenuation. These findings were further supported by the significant correlation among the values of TSICHL ? TSISD and nonvolatile suspended solids and water residence time. The logarithmic model showed that an equivalent TSICHL and TSISD could be found at τ?=?54 days in the TGR (Fig. 7). Accordingly, nonalgal particulates dominated light attenuation and limited algal biomass of the reservoir when τ?<?54 days.  相似文献   
960.
This paper quantifies the allocation of ecosystem services value (ESV) associated with land use pattern and qualitatively examined impacts of land use changes and socio-economic factors on spatiotemporal variation of ESV in the Natural Wetland Distribution Area (NWDA), Fuzhou city, China. The results showed that total ESV of the study area decreased from 4,332.16?×?106 RMB Yuan in 1989 to 3,697.42?×?106 RMB Yuan in 2009, mainly due to the remarkable decreases in cropland (decreased by 55.3 %) and wetland (decreased by 74.2 %). Forest, water, and wetland played major roles in providing ecosystem services, accounting for over 90 % of the total ESV. Based on time series Landsat TM/ETM+ imagery, geographic information system, and historical data, analysis of the spatiotemporal variation of ESV from 1989 to 2009 was performed. It indicated that rapid expansion of urban areas along the Minjiang River resulted in significant changes in land use types, leading to a dramatic decline in ecosystem services. Meanwhile, because of land scarcity and unique ecosystem functions, the emergency of wetland and cropland protection in built-up area has become an urgent task of local authorities to the local government. Furthermore, there was still a significant negative correlation between ESV of cropland and wetland and the GDP. The results suggest that future planning of land use pattern should control encroachment of urban areas into cropland and wetland in addition to scientific and rational policies towards minimizing the adverse effects of urbanization.  相似文献   
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