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291.
Aluminum salt coagulants were used prevalently in various water works.In this article,the effects of filtration on residual aluminum concentration and species distribution were researched by determining the concentration of diiferent aluminum species before and after single layer filter,double layer filter,and membrane filtration units.In the research,size exclusion chromatography(SEC)was used to separate colloidal and soluble aluminum,ion exchange chromatography(IEC)was used to separate organic and inorganic aluminum, and inductivity coupled plasma-atomic emission spectrometry(ICP-AES)was used to determine the aluminum concentration.The results showed that the rapid filtration process had the ability of removing residual aluminum from coagulant effluent water,and that double layer filtration was more effective in residual aluminum removal than single layer filtration,while nano filtration was more effective than micro filtration.It was found that when the residual aluminum concentration was below 1mg/L in sediment effluent,the residual aluminum concentration in treated water was above 0.2 mg/L.The direct rapid filtration process mainly removed the suspended aluminum.The removal of soluble and colloidal aluminum was always less than 10% and the natural small particles that adsorbed the amount of soluble or small particles aluminum on their surface were difficult to be removed in this process.Micro filtration and nano filtration were good technologies for removing aluminum;the residual aluminum concentration in the effluent was less than 0.05 mg/L.  相似文献   
292.
Various kinds of pathogenic bacteria derived from the intestinal tract of animals exist in compost material like cow dung.In order to sterilize the pathogenic bacteria completely in compost material,the cow dung was put into a heat treatment machine in pilot plan, and harmless condition in short time was examined.The results indicated,pathogenic indicator bacteria such as coliform bacteria, fecal coliform,Escherichia coli and salmonella were all 10~6 cfu/g dw at the beginning,died rapidly when cow dung temperature rose to above 50℃,and not detected at 54-68℃for 6-24 h heat treatment.Coliform bacteria and salmonella in heated cow dung were not detected by re-growth culture and enrichment culture examination.Moreover,it was hardly influenced on the fermentation ability of composting microbe,organic decomposition bacteria.During heat treatment,the mesophile decreased rapidly and the thermophile stabilized or increased,and the most of composting microbe were bacillus in cow dung by fluorescence microscope,this indicated that bacillus was dominator and composting microbe in composting process.  相似文献   
293.
不同稻渔系统对池塘养殖尾水的净化效果分析   总被引:1,自引:0,他引:1  
采用围隔实验法考察不同虾蟹共作稻渔系统对养殖尾水的净化效果.结果表明:稻田及分别投放小龙虾和河蟹等稻渔共作系统均对养殖尾水净化作用显著,且相互间基本无显著差异(P>0.05);稻渔系统对水体中氨氮、亚硝氮、TN和TP的最大去除率分别为67.48%、78.13%、37.97%和53.05%;养殖尾水中IMn与悬浮物于1 ...  相似文献   
294.
During the aging process, ferrihydrite was transformed into mineral mixtures composed of different proportions of ferrihydrite, goethite, lepidocrocite and hematite. Such a transformation may affect the fixed ability of arsenic. In this study, the stability of Fe-As composites formed with As(V) and the minerals aged for 0, 1, 4, 10 and 30 days of ferrihydrite were systematically examined, and the effects of molar of ratios Fe/As were also clarified using kinetic methods combined with multiple spectroscopic techniques. The results indicated that As(V) was rapidly adsorbed on minerals during the initial polymerization process, which delayed both the ferrihydrite conversion and the hematite formation. When the Fe/As molar ratio was 1.875 and 5.66, the As(V) adsorbed by ferrihydrite began to release after 6 hr and 12 hr, respectively. The corresponding release amounts of As(V) were 0.55 g/L and 0.07 g/L, and the adsorption rates were 92.43% and 97.50% at 60 days, respectively. However, the As(V) adsorbed by the transformation products aged for 30 days of ferrihydrite began to release after adsorbed 30 days. The corresponding release amounts of As(V) were 0.25 g/L and 0.03 g/L, and the adsorption rates were 84.23% and 92.18% after adsorbed 60 days, for the Fe/As=1.875 and 5.66, respectively. Overall, the combination of As(V) with ferrihydrite and aged products transformed from a thermodynamically metastable phase to a dynamically stable state within a certain duration. Moreover, the aging process of ferrihydrite reduced the sorption ability of arsenate by iron (hydr)oxide but enhanced the stability of the Fe-As composites.  相似文献   
295.
环境雌激素对男性生育因子的破坏作用   总被引:3,自引:0,他引:3  
魏爱雪  徐晓白 《环境化学》2004,23(6):707-712
本文介绍了环境雌激素多氯联苯(PCBs)和酞酸酯(PEs)对男性生育因子的破坏作用,以及PCBs和PEs对精液参数的作用机制.对生育和不育男性的精液参数间的差异、精液异雌激素和精液参数间的相关性,以及不同范畴的不育男性精液质量的分析表明,PCBs和PEs对无明显病原学的不育男性的精液质量可能有破坏作用.  相似文献   
296.
藻细胞不同生长阶段的海泡石凝聚除藻性能   总被引:10,自引:3,他引:7  
陈灏  潘纲  张明明 《环境科学》2004,25(6):85-88
对铜绿微囊藻(Microcystis aeruginosa 469)的4个不同生长阶段:延迟末期,对数中期,对数末期和衰老初期的表面疏水性(疏水分配法)和表面电性(Zeta电位)进行了测定,并利用0.2 g/L的海泡石进行了凝聚除藻性能实验.结果显示以上4个生长阶段的藻细胞表面疏水性平均为:64%, 48%, 58%和70%,而凝聚沉降60 min后的藻细胞去除效率为:97%, 87%, 81%和99%,表明藻细胞表面疏水性与粘土凝聚性能之间有较好的相关性(R=0.7~0.8),但与表面电性的关系不大.M.A.469各个生长阶段的表面疏水性和凝聚性能的强弱顺序可依次确定为:衰老期>延迟期>对数增长期.  相似文献   
297.
本文通过淮南台CZB-2型竖直摆钻孔倾斜仪二年观测资料分析,给出了该仪器的映震能力;震后效应;前兆异常的方向性特征,为捕捉淮南近区中强地震提供详实的短临预报依据。  相似文献   
298.
森林凋落物对土壤酸化缓冲作用的初步研究   总被引:6,自引:0,他引:6  
汪思龙  陈楚莹 《环境科学》1992,13(5):25-30,5
阔叶树木荷凋落物的灰分元素含量以及分解速率大大高于针叶树杉木凋落物。相比之下,木荷凋落物具有较高的缓冲酸化的潜在能力。覆盖木荷凋落物的土壤,其下渗液盐基含量和PH值与对照相比显著较高,而土壤本身的盐基饱和度和有机质含量也显著较高,土壤酸度和Al/Ca显著较低,即太荷凋落物对土壤酸化有较高的缓冲能力,而杉木凋落物则不然。  相似文献   
299.
关于新疆环境应急能力建设的探讨   总被引:3,自引:0,他引:3  
王保民 《干旱环境监测》2006,20(4):249-250,F0004
阐述了新疆环境应急能力建设的重要性,对新疆环境应急现状中存在的问题进行了分析,提出了加强环境应急能力建设的几点建议。  相似文献   
300.
1IntroductionThesoutheastareasofShanxiProvincestandinthesoutheastoftheLoesPlateauandhaveavariedtopography.Thesoiloftheseareas...  相似文献   
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