全文获取类型
收费全文 | 6410篇 |
免费 | 549篇 |
国内免费 | 1559篇 |
专业分类
安全科学 | 569篇 |
废物处理 | 196篇 |
环保管理 | 422篇 |
综合类 | 4291篇 |
基础理论 | 1050篇 |
污染及防治 | 760篇 |
评价与监测 | 867篇 |
社会与环境 | 272篇 |
灾害及防治 | 91篇 |
出版年
2024年 | 66篇 |
2023年 | 207篇 |
2022年 | 275篇 |
2021年 | 298篇 |
2020年 | 301篇 |
2019年 | 344篇 |
2018年 | 196篇 |
2017年 | 218篇 |
2016年 | 315篇 |
2015年 | 365篇 |
2014年 | 776篇 |
2013年 | 410篇 |
2012年 | 482篇 |
2011年 | 508篇 |
2010年 | 390篇 |
2009年 | 537篇 |
2008年 | 386篇 |
2007年 | 390篇 |
2006年 | 303篇 |
2005年 | 293篇 |
2004年 | 205篇 |
2003年 | 173篇 |
2002年 | 137篇 |
2001年 | 131篇 |
2000年 | 101篇 |
1999年 | 99篇 |
1998年 | 69篇 |
1997年 | 76篇 |
1996年 | 86篇 |
1995年 | 82篇 |
1994年 | 73篇 |
1993年 | 58篇 |
1992年 | 58篇 |
1991年 | 35篇 |
1990年 | 25篇 |
1989年 | 42篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 1篇 |
排序方式: 共有8518条查询结果,搜索用时 15 毫秒
881.
882.
883.
薄层色谱紫外分光光度法定量测定微生物发酵产物辅酶Q10 总被引:1,自引:0,他引:1
报道了一种微生物发酵液中辅酶Q10的定量检测方法.该方法分为两个步骤:第一步是离心收集菌体和结合使用超声波处理的辅酶Q10丙酮抽提;第二步是硅胶薄层色谱,根据标样位置取产物斑点乙醇洗脱后用紫外分光光度法测定辅酶Q10含量.结果表明,该方法具有操作简便、重复性好、相对误差小等优点,可用于细菌发酵生产辅酶Q10研究过程中发酵产物的快速定量检测.图2表2参6 相似文献
884.
885.
乌江干流中上游水电梯级开发水温累积效应 总被引:2,自引:0,他引:2
以乌江流域洪家渡库尾至乌江渡坝下的水电工程干扰典型段为研究区域,利用建坝前后的水温实测资料,采用建坝前天然水温和建坝后下泄水温比较法,对乌江干流梯级水库水温时空分布特征进行分析。研究结果表明:对天然水温改变最大的电站为洪家渡和乌江渡,前者是受水库水温结构自身影响,后者是梯级联合运行的结果;梯级联合运行使库区水温分层有所减弱,随着时间的推移或上游梯级电站的建成,电站下泄水温年变化过程趋于均化,与天然水温的延迟也越加明显;不同的水库水温结构对水温累积效应的影响也各不相同,稳定分层型水库对水温累积具有正效应,混合型水库具有负效应,过渡型水库处于两者之间,体现了梯级电站的水温累积影响,为研究减缓下泄低温水的对策措施提供依据和参考。 相似文献
886.
IonPac SCS1柱用于非抑制型电导检测或单柱离子色谱(SCIC).特别适用于分析常见无机阳离子、铵离子、选择性烷醇胺以及过渡金属,如锌和铜离子.应用领域为发电、化学、石化和环境等行业. 相似文献
887.
888.
以顶空气相色谱法测定了环境大气及水质听醇类污物。选择了最佳盐析条件及条件采样方法,用SE-5450m*530μm毛细管柱分离,给出了氢火焰离子化检测器。 相似文献
889.
This study was designed to clarify the influence of operating conditions on the formation and emissions of polychlorinated-pdibenzodioxins and dibenzofurans (PCDD/Fs) from a sintering process with hot flue gas recycling. A pilot scale sinter pot with simulated flue gas recycling was developed, and four key operational parameters, including temperature, oxygen content of the simulated waste flue gas, the coke rate of the sintering mixture, and the quicklime quality, were selected for exploring PCDD/Fs formation. The results showed that the temperature of the recycled flue gas had a major affect on PCDD/Fs formation, and a high temperature could significantly increase their formation during sintering. A clear linear correlation between the temperature of recycling flue gas and PCDD/Fs emission (r = 0.93) was found. PCDD/Fs could be reduced to a certain extent by decreasing the level of oxygen in the recycled flue gas, while sintering quality was unchanged. The coke rate had no significant influence on the formation of PCDD/Fs, but the quality of quicklime used in the sintering mixture could affect not only the amount of PCDD/Fs emissions but also the sintering productivity. Compared with a benchmark sinter pot test, PCDD/Fs emissions markedly decreased with improvements to quicklime quality. However, the reduction in PCDD/Fs emissions realized by using high-quality quicklime was limited by the temperature of the inlet gas. The highest reduction achieved was 51% compared with conventional quicklime when the temperature of the inlet gas was 150°C. 相似文献
890.
A GFP-based bacterial biosensor with chromosomally integrated sensing cassette for quantitative detection of Hg(II) in environment 总被引:3,自引:0,他引:3
Himanshu Priyadarshi Absar Alam Gireesh-Babu P Rekha Das Pankaj Kishore Shivendra Kumar Aparna Chaudhari 《环境科学学报(英文版)》2012,24(5):963-968
A mercury biosensor was constructed by integrating biosensor genetic elements into E. coli JM109 chromosome in a single copy number, using the attP/attB recombination mechanism of λphage. The genetic elements used include a regulatory protein gene (merR) along with operator/promoter (O/P) derived from the mercury resistance operon from pDU1358 plasmid of Serratia marcescens. The expression of reporter gene gfp is also controlled by merR/O/P. Integration of the construct into the chromosome was done to increase the stability and precision of the biosensor. This biosensor could detect Hg(II) ions in the concentration range of 100-1700 nmol/L, and manifest the result as the expression of GFP. The GFP expression was significantly different (P ≤ 0.05) for each concentration of inducing Hg(II) ions in the detection range, which reduces the chances of misinterpretation of results. A model using regression method was also derived for the quantification of the concentration of Hg(II) in water samples. 相似文献