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51.
聚合氯化铝铁絮凝剂的性能研究 总被引:32,自引:2,他引:32
煤矸石是采煤过程之废料。本文利用煤矸石制备出了聚合氯化铝铁(PAFC):一种新型无机高分子絮凝剂,探讨了Fe^3+的稳定性与溶液离子强度之间的关系,发现溶液的离子强度越大,则产生Fe(OH)3沉淀时的PH越高。研究了PAFC水解产物的ζ电位及絮凝效果随PH的变化情况,比较了PAFC、PAC和PFS的除浊性能,PAFC在PH为7.0-8.2范围内除浊效果最佳,PAFC的除浊效果优于PAC。 相似文献
52.
城市污水回用三种处理工艺的选择 总被引:1,自引:0,他引:1
本文针对我国城市二级出水的特点,研究了污水深度处理的三种工艺:絮凝沉淀过滤、微絮凝过滤和直接过滤.装置采用网格反应池、翼片斜板沉淀池、气水同时冲洗粗砂滤池.药剂选用聚合硫酸铁,试验规模120m~3/d. 相似文献
53.
金属氢氧化物包被砂过滤柱吸附与去除水体中的微生物 总被引:1,自引:0,他引:1
郑耀通 《应用与环境生物学报》2004,10(4):475-479
以氢氧化铁与氢氧化铝原位沉积包被砂作介质的过滤柱 ,用于去除脱氯自来水中人为污染的高浓度脊髓灰质炎病毒PV1、脆弱拟杆菌噬菌体B .fp和大肠杆菌E .coli.结果显示 ,包被修饰砂颗粒表面Zeta电动势由原来的 - 4 2 .8mV上升到 5 4 .7mV ,并因此提高了对微生物的吸附去除能力 .修饰砂过滤柱经 12 .5d连续过滤 30 0L水样后 ,仍可使进水微生物浓度分别高达n(cfu) /mL-1=5 .2× 10 6、2 .4× 10 5、2 .3× 10 5的E .coli、B .fp和PV1去除 92 %、97.2 %和 99.6 % .而未修饰砂柱 ,在相同条件下仅分别去除 5 3%、5 9%和 70 .6 % .修饰砂柱可在较大pH变化下稳定高效地去除微生物且在中性条件下效果最佳 ,这与未修饰砂柱明显不同 .扫描电镜显示 ,两种砂具有明显不同的表面结构 .修饰砂柱流出液中检测不到用于包被的铁、铝金属 ,说明氢氧化铁、氢氧化铝修饰物同砂结合牢固并因此提高了砂过滤柱的使用寿命 .修饰砂过滤介质可为饮用水处理提供更为安全可靠的去除病原微生物方法 .图 4表 4参 19 相似文献
54.
Variation in the endospermal protein patterns of seeds amongst and between inland and coastal populations of the dune building
grassLeymus arenarius was examined in Iceland. Seeds were collected from six coastal populations and five inland populations in Iceland. Endospermal
proteins (prolamins) of seeds were extracted with Tris-buffered 2-propanol (50%) and β-mercaptoethanol (0.5% v/v). We used
8% and 12% sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to separate the prolamin protein bands, which
were stained with Coomassie Brilliant Blue R. Coastal populations were differentiated from inland populations on the basis
of high frequency of high molar weight (HMW) (110–150 kg mol−1) prolamins. Coastal populations had significantly higher proportions of their seed with more than two HMW prolamins, than
those of inland populations. Subtle differences were found among the HMW prolamins of coastal and inland populations indicating
limited intrapopulation variation. The dynamic environment of sand dunes probably influences the genetic composition of these
populations. The results suggest that seeds of the inland and coastal populations should be treated separately in sand dune
reclamation and restoration works 相似文献
55.
Anestis Filippidis Panagiotis Misaelides Alexander Clouvas Athanasios Godelitsas Nikolaos Barbayiannis Ioannis Anousis 《Environmental geochemistry and health》1997,19(2):83-88
A black-sand formation located at Touzla Cape, near Thessaloniki city, Greece, was investigated using optical microscopy, powder-XRD, SEM-EDS, INAA and in-situ -ray spectrometry. This black sand is mainly composed of ilmenite, magnetite, garnet, zircon and rutile. Also present, in minor or trace amounts, are quartz, sphene, pyroxenes, sillimanite, feldspars, biotite, haematite, tourmaline, chromite, niobian-rutile and pyrrhotite. Niobian-rutile and pyrrhotite were found as inclusions in ilmenite and magnetite respectively. The radioactivity measurements indicated contributions of the uranium and thorium radioactive series and of 40K and 137Cs, and the maximum value of the total absorbed dose rate in air was found to be 62, 172, 8 and 2 nGy h-1 respectively. The main radioactivity of the uranium and thorium series is attributed to the fractions of zircon (304 µg Th g-1 and 157 µg U g-1), of ilmenite (89 µg Th g-1) and to a lesser extent to the fraction of garnet (5 µg Th g-1). The zircon fraction also contained 5076 µg Hf g-1. Some minerals and elements (Ti, Zr, Hf, Th, U) contained in the black sand could be of potential economic value. The high proportions of monomineralic grains along with the variations observed in mineral phases, in colour, in sphericity, in roundness, in grain size, in composition and in mineral inclusions, imply that the minerals and grains were subjected to several cycles of weathering and sedimentation, as well as being derived from multiple source rocks and areas. 相似文献
56.
煤矸石复垦中的氮素积累途径 总被引:7,自引:0,他引:7
进行了煤矸石上种植接菌种草及加覆盖物种植牧草的盆栽和小区试验。结果表明,接菌种植可以显著提高植物的固氮酶活性和结瘤率,改善煤矸石的氮素贫瘠状况,促进牧草根系和地上部分的生长和煤矸石的进一步风化;这些结果在施氮量中等区w(N)=15g/100kg更为明显。同时在煤矸石上加薄层覆盖物种植豆科植物,对其氮素的积累提高和生物性状的同样具有明显的促进作用,并以黄土覆盖效果更佳。这些结果为解决煤矸石复垦中氮素缺乏的问题提供了有效途径。表3参4 相似文献
57.
聚硫氯化铝絮凝效果及在水处理中的应用 总被引:8,自引:0,他引:8
采用聚硫氯化铝(PACS)为絮凝剂进行废水处理试验,对其絮凝效果及影响因素进行了研究,试验结果表明,PACS的SO4^2-含量,碱化度,投加量和水的pH对絮凝效果有影响,当Al^3+/SO4^2-(摩尔比)为14 ̄16,碱化度为65% ̄70%,pH为6 ̄9、PACS投加量为2 ̄4mg/L时,絮凝效果最佳,试验结果还表明,PACS比聚氯化铝(PAC)的絮凝效果好。 相似文献
59.
食品生产废水属于高浓度有机废水,具有排水量大、污染物浓度、水质水量变化大的特点,如不处理就直接排放,将会对水环境造成严重的污染.本工程中废水原水水质参数为:CODCr<5000mg/L,BOD5<3000mg/L,SS<500mg/L,pH5.0~7.5,水温20~30℃.针对该废水水质特点,采用气浮-生化-砂滤工艺处理食品生产废水.运行结果表明,该处理工艺具有处理效率高、操作管理简便、抗冲击负荷、污泥量小、出水水质稳定、运行成本低等优点,处理后出水CODCr85mg/L,BOD524.3mg/L,SS56.2mg/L,pH6~8,达到<污水综合排放标准>(GB8978-1996)中的一级标准. 相似文献
60.
Large amounts of 137Cs have been accidentally released to the subsurface from the Hanford nuclear site in the state of Washington, USA. The cesium-containing liquids varied in ionic strengths, and often had high electrolyte contents, mainly in the form of NaNO3 and NaOH, reaching concentrations up to several moles per liter. In this study, we investigated the effect of ionic strengths on Cs migration through two types of porous media: silica sand and Hanford sediments. Cesium sorption and transport was studied in 1, 10, 100, and 1000 mM NaCl electrolyte solutions at pH 10. Sorption isotherms were constructed from batch equilibrium experiments and the batch-derived sorption parameters were compared with column breakthrough curves. Column transport experiments were analyzed with a two-site equilibrium-nonequilibrium model. Cesium sorption to the silica sand in batch experiments showed a linear sorption isotherm for all ionic strengths, which matched well with the results from the column experiments at 100 and 1000 mM ionic strength; however, the column experiments at 1 and 10 mM ionic strength indicated a nonlinear sorption behavior of Cs to the silica sand. Transport through silica sand occurred under one-site sorption and equilibrium conditions. Cesium sorption to Hanford sediments in both batch and column experiments was best described with a nonlinear Freundlich isotherm. The column experiments indicated that Cs transport in Hanford sediments occurred under two-site equilibrium and nonequilibrium sorption. The effect of ionic strength on Cs transport was much more pronounced in Hanford sediments than in silica sands. Effective retardation factors of Cs during transport through Hanford sediments were reduced by a factor of 10 when the ionic strength increased from 100 to 1000 mM; for silica sand, the effective retardation was reduced by a factor of 10 when ionic strength increased from 1 to 1000 mM. A two order of magnitude change in ionic strength was needed in the silica sand to observe the same change in Cs retardation as in Hanford sediments. 相似文献