全文获取类型
收费全文 | 1903篇 |
免费 | 110篇 |
国内免费 | 711篇 |
专业分类
安全科学 | 170篇 |
废物处理 | 104篇 |
环保管理 | 173篇 |
综合类 | 1102篇 |
基础理论 | 314篇 |
污染及防治 | 642篇 |
评价与监测 | 68篇 |
社会与环境 | 59篇 |
灾害及防治 | 92篇 |
出版年
2024年 | 4篇 |
2023年 | 30篇 |
2022年 | 87篇 |
2021年 | 82篇 |
2020年 | 76篇 |
2019年 | 48篇 |
2018年 | 69篇 |
2017年 | 90篇 |
2016年 | 83篇 |
2015年 | 89篇 |
2014年 | 143篇 |
2013年 | 186篇 |
2012年 | 179篇 |
2011年 | 158篇 |
2010年 | 125篇 |
2009年 | 130篇 |
2008年 | 139篇 |
2007年 | 120篇 |
2006年 | 109篇 |
2005年 | 87篇 |
2004年 | 42篇 |
2003年 | 77篇 |
2002年 | 72篇 |
2001年 | 64篇 |
2000年 | 52篇 |
1999年 | 65篇 |
1998年 | 56篇 |
1997年 | 43篇 |
1996年 | 45篇 |
1995年 | 40篇 |
1994年 | 26篇 |
1993年 | 29篇 |
1992年 | 27篇 |
1991年 | 17篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 10篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
排序方式: 共有2724条查询结果,搜索用时 31 毫秒
861.
Hui Xie Lusheng Zhu Tingting M Jun Wang Jinhua Wang Jun Su Bo Shao 《环境科学学报(英文版)》2010,22(12):1930-1935
The free enzyme extracted from WZ-I,which was identified as Fusarium LK.ex Fx,could effectively degrade chlorpyrifos,an organophosphate insecticide.The methods of immobilizing this free enzyme and determined its degradation-related characteristics were investigated.The properties of the immobilized enzyme were compared with those of the free enzyme.The optimal immobilization of the enzyme was achieved in a solution of 30 g/L sodium alginate at 4°C for 4-12 hr.The immobilized enzyme showed the maximal activity at pH 8.0,45°C.The maximum initial rate and the substrate concentration of the immobilized enzyme were less than that of the free enzyme.The immobilized enzyme,therefore,had a higher capacity to withstand a broader range of temperatures and pH conditions than the free enzyme.With varying pH and temperatures,the immobilized enzyme was more active than the free enzyme in the degradation reaction.In addition,the immobilized enzyme exhibited only a slight loss in its initial activity,even after three repeated uses.The results showed that the immobilized enzyme was more resistant to different environmental conditions,suggesting that it was viable for future practical use. 相似文献
862.
863.
研究了以城市垃圾中3种典型的固体有机废弃物——锯木屑、纸张和塑料的热解产物(分别简称木炭、纸炭和塑料热解物)为原料,水蒸气为活化剂制备废弃物基活性炭时钙化物含量对活化过程、活性炭吸附性能(以碘值表征)及其孔结构的影响。结果表明,钙化物可加快活化反应的速度,且钙化物含量在1.5%时活化反应速度即已不再随钙化物含量的增加而增加;活性炭的吸附性能则随钙化物含量的增加而减少,同时钙化物对活性炭的孔径分布基本无影响,但降低了活性炭的比表面积、微孔孔容及中孔孔容;钙化物的2种前驱体(即CaO和Ca(OH)2)对活化过程具有相同的催化作用。 相似文献
864.
延迟焦化装置的定量风险评估 总被引:1,自引:0,他引:1
通过长岭分公司延迟焦化装置的定量风险评估,明确了装置中的主要危险设备,量化出装置的整体风险水平,促进了企业的安全生产. 相似文献
865.
工业废弃场地再开发的环境评估:Ⅱ健康风险评估 总被引:4,自引:0,他引:4
工业废弃场地往往受到严重的土壤地下水污染,再开发往往会给公众带来潜在健康风险。对河南某城市一工业废弃污染场地进行了健康风险评估。根据未来土地利用状况,分剐对居住场景和建筑场景的健康风险进行了评估。在居住场景下,总石油烃会引起较高的非致癌风险,而苯会通过口腔摄入和呼吸摄入导致较高的致癌风险。假如长期饮用MW—1附近区域的地下水时,苯和总石油烃会给居民带来不可接受的非致癌风险。同时苯还会带来较高的致癌风险。在建筑场景下,由于较短的暴露周期,场地污染不会带来不可接受的风险。为保护未来居民的健康,应当在场地开发为住宅小区前进行污染区域的修复。 相似文献
866.
氢化物发生原子荧光法测定地表水和饮用水中的痕量砷、汞、硒 总被引:3,自引:0,他引:3
文章研究了用SK-2002 AFS analyser氢化物发生原子荧光法测定地表水和饮用水中的砷、汞、硒的测定。在5%的酸度条件下加入5%硫脲+5%抗坏血酸,20g/L的硼氢化钾为还原剂,调整仪器的空气和辅气流量及分析条件为文中条件,取水样中分别添加砷,汞,硒,使它们的浓度分别为2μg/L,0.4μg/L,4μg/L,连续测定12次,以砷,汞,硒的相对标准偏差分别为0.4%,1.1%,1.2%。取水样加入As,Hg,Se标准分别为2.0ng,0.6ng,4.0ng,测定的添加标准回收率分别为99.5%,97.5%,95.8%。研究结果表明,该方法操作简便,快速,灵敏,干扰少,检出限低等特点,适合于测定地表水和饮用水中砷,汞,硒的测定。 相似文献
867.
西南喀斯特地区石漠化问题研究综述 总被引:3,自引:0,他引:3
喀斯特地区石漠化是在脆弱的生态地质背景基础上叠加了人类活动而出现的。西南地区的石漠化面积现仍约以2500km^2/a的速度进一步扩大。石漠化的生态治理工作的目的就是要在人为作用的干扰下,使这种逆向演替转变为顺向演替。石漠化治理思路设计的科学性、战略性、可行性决定了最后石漠化的治理结果。在喀斯特石漠化的治理中,要根据不同岩溶环境类型区及石漠化发育的不同程度和不同山地的立地条件,针对其特点,选择多种途径,运用恰当的恢复技术,制定出具体的开发治理措施,实行规模治理,以提高资源利用率,促进石漠化生态环境的综合治理。 相似文献
868.
介绍了齐齐哈尔市建华区环保局污染源普查工作,严格按照全国污染源普查办的统一要求,开展普查工作.主要工作流程有领导重视、大力宣传、统一思想、培训队伍、做好拉网清查,认真核实汇总,严格审查等工作流程.从而保证了污染源普查工作科学有序、高效优质的圆满完成. 相似文献
869.
Chunyan YU Xie QUAN Xiaoxia OU Shuo CHEN 《Frontiers of Environmental Science & Engineering in China》2008,2(3):291-296
Four fractions (A, B, C, and D) of humic acids (HAs) were separated based on the polarity from weak to strong. UV-vis absorption
and Fourier transform infrared spectroscopy (FTIR) analysis show that the fractions C and Dpossessedmore aromatic C=C content.
The influences of HAs and their fractions on the photolysis were investigated by the photodegradation of 2,4-D solutions under
simulated solar light irradiation. The degradation rate of 2,4-D was found to decrease in the presence of bulk HAs or their
fractions especially at high HAs concentration. The fractions of strong polarity C and D retarded the degradation rate more
than the fractions of weak polarity A and B. This could be attributed to the different absorption intensity of the four HAs
fractions in the order of D ⩾ C > A > B, and the stronger π-π electron donor-acceptor interactions between the strong polar
fractions and 2,4-D. 相似文献
870.
Occurrence of phthalate esters in water and sediment of urban lakes in a subtropical city, Guangzhou, South China 总被引:14,自引:0,他引:14
Extensive use of phthalate esters (PAEs) in both industrial processes and consumer products has resulted in the ubiquitous presence of these chemicals in the environment. This study reports the first data on the concentrations of 16 phthalate esters (PAEs) in water and sediments of the urban lakes in Guangzhou City. PAEs were detected in all samples analyzed, mainly originating from urban stormwater runoff, atmospheric deposition, as well as untreated discharge of industrial wastewater and municipal sewage. The Sigma(16)PAEs concentrations in water and sediments ranged from 1.69 to 4.72 microg L(-1) and 2.27 to 74.94 microg g(-1)-dry weight (dw), with the mean concentrations of 2.91 microg L(-1) and 20.85 microg g(-1)-dw, respectively, which indicates that sediment is a significant sink for PAEs. Variability of the Sigma 16PAEs concentrations in water and sediment in the urban lakes was almost consistent. The spatial distribution of PAEs was site-specific. Of the 16 PAEs, DMP, DEP, DnBP, DiBP, DMPP, and DEHP were present in all water and sediment samples. DnBP was abundant in water (53.0-81.2%), while no single dominant congener was found in sediments. The abundances of DiBP were similar to those of DEHP, and DiBP and DEHP collectively accounted for 77.2-97.6% of the Sigma 16PAEs concentrations. Congener specific analysis confirmed that DnBP was a predictive indicator for the dissolved summation operator16 PAEs concentration (correlation coefficient r=0.968, p<0.01), and that DiBP was a predictive indicator for the sediment summation operator16 PAEs concentration (r=0.975, p<0.01). As compared to the results for other studies, the urban lakes of Guangzhou were moderately polluted by PAEs. 相似文献