全文获取类型
收费全文 | 163篇 |
免费 | 3篇 |
国内免费 | 31篇 |
专业分类
安全科学 | 5篇 |
废物处理 | 18篇 |
环保管理 | 5篇 |
综合类 | 102篇 |
基础理论 | 35篇 |
污染及防治 | 20篇 |
评价与监测 | 7篇 |
社会与环境 | 4篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 3篇 |
2014年 | 2篇 |
2013年 | 22篇 |
2012年 | 5篇 |
2011年 | 4篇 |
2010年 | 5篇 |
2009年 | 6篇 |
2008年 | 7篇 |
2007年 | 7篇 |
2006年 | 10篇 |
2005年 | 16篇 |
2004年 | 19篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 15篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有197条查询结果,搜索用时 15 毫秒
181.
Thomas M. Scherer R. Clinton Fuller Robert W. Lenz 《Journal of Polymers and the Environment》1994,2(4):263-269
The bacterial polyester, poly(p1/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxybutyrate-co-p1/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-hydroxyvalerate) (PHB/V), was cross-linked with 1, 5, 7, 10, 20, and 30 wt% benzoyl peroxide by thermal decomposition reactions. Solvent extractions were carried out to determine the cross-linked fractions of the films. The sol/gel data were used to estimate cross-link densities. Films of PHB/V cross-linked with 10% benzoyl peroxide were placed in contact with purified depolymerase A secreted byP. lemoignei. These samples exhibited weight loss rates which were half that of un-cross-linked PHB/V, but the network was degraded completely by the enzyme. The results of this study suggest that anendo-type enzymatic degradation may occur, in addition to theexo-type activity, which is normally presumed to occur with theP. lemoignei depolymerase system. 相似文献
182.
Plant volatiles affect oviposition by codling moths 总被引:4,自引:0,他引:4
Peter Witzgall Lena Ansebo Zhihua Yang Gino Angeli Benoit Sauphanor Marie Bengtsson 《Chemoecology》2005,15(2):77-83
Summary. Oviposition in wild codling moth females, collected as overwintering larvae from apple, pear and walnut, was stimulated by volatiles from fruit-bearing green branches of these respective hostplants. Analysis of headspace collections showed that eight compounds present in apple, pear and walnut elicited a reliable antennal response in codling moth females: (E)-p68655v3n2j553h0/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-ocimene, 4,8-dimethyl-1,(E)3,7-nonatriene, (Z)3-hexenyl acetate, nonanal, p68655v3n2j553h0/xxlarge946.gif" alt="beta" align="MIDDLE" BORDER="0">-caryophyllene, germacrene D, (E,E)-p68655v3n2j553h0/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene, and methyl salicylate. Any one of these compounds is found in many other non-host plants, and host recognition in codling moth is thus likely encoded by a blend of volatiles. A large variation in the blend proportion of these compounds released from apple, pear and walnut suggests a considerable plasticity in the female response to host plant odours. Wild females, collected as overwintering larvae in the field, laid significantly fewer eggs in the absence of host plant volatiles. The offspring of these females, however, reared on a semi-artificial diet in the laboratory, laid as many eggs with or without plant volatile stimulus. Tests with individual females showed that this rapid change in oviposition behaviour may be explained by selection for females which oviposit in the absence of odour stimuli, rather than by preimaginal conditioning of insects when rearing them on semi-artificial diet. Oviposition bioassays using laboratory-reared females are therefore not suitable to identify the volatile compounds which stimulate egglaying in wild females. 相似文献
183.
Summary Feeding by the homopteranPsylla pyricola on leaves of pear trees induces the production of volatile compounds, such as (E,E)-p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene and methyl-salicylate, as well as the production of polyphenols. The inference on induction is based on GC-MS and HPLC chromatograms from the same samples ofPsylla infested leaves, leaves from the same pear tree beforePsylla infestation and uninfested leaves from other pear trees.Psylla infestation greatly enhanced the production of volatiles ((E,E)-p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene, methyl-salicylate and others) and triggered the production of new polyphenols, characterized by much longer retention times.However, the responses to infestation depend critically on leaf age (defined by leaf distance to apex). With respect to the leaf volatiles it appears that infested, old leaves produce fewer compounds and lower amounts of the volatiles than infested, young leaves. Moreover, there seem to be differences in pattern. Relative to (E,E)-p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene, methyl-salicylate was found in much lower amounts in heavily infested, old leaves. With respect to polyphenols it was found that infested old leaves collected in August have polyphenols with the same retention times, but more or less equal amounts as uninfested young leaves collected in May. This shows thatPsylla infestation causes the induced response mostly in young leaves.The induced leaf volatiles may act as synomones to heteropteran bugs. As shown elsewhere,Anthocoris nemoralis responds significantly to (E,E)-p7500x79/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-farnesene and methyl-salicylate when offered in pure form against clean air in a Y-tube olfactometer. The effect of polyphenols on the performance ofP. pyricola is not yet known. Hence, a role in direct defence is still to be investigated. 相似文献
184.
Arie Nissenbaum Jürgen Rullkötter Yoseph Yechieli 《Environmental geochemistry and health》2002,24(4):327-335
Deep black clayey sediments of the Dead Sea, previously covered with water at times of higher sea level, are being mined for therapeutic purposes and for the preparation of cosmetic products under the name pv46n2p1m9p3k131/xxlarge8216.gif" alt="lsquo" align="BASELINE" BORDER="0">Black Mudpv46n2p1m9p3k131/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">. It was claimed that the beneficial properties are due to the presence of bitumen (asphalt) as attested by the colour. Less commonly, the curative properties have been ascribed to humic acids or to organic matter derived from algae in the lake. Asphalt from the Dead Sea has been of major economic importance to the region and was used as a medication for 2000 years until the mid-20th century. Geochemical analysis of the Black Mud showed that it contains relatively little organic matter (ca. 0.6–0.8% organic carbon) and that the organic matter is mostly derived from the land masses surrounding the lake. Asphalt was totally absent and the concentration of humic acids very low. The black colour of the mud is rather due to the poorly crystallised iron sulphides. Based on this, the therapeutic properties of the mud are ascribed to its content of reduced sulphur species, its physical and chemical properties and possibly its brine content, but not to the presence of organic matter. 相似文献
185.
186.
187.
188.
对氨基酚生产废水处理的研究状况 总被引:11,自引:1,他引:10
介绍了近10年来对氨基酚生产废水处理方法的研究现状及3种主要处理方法-物化法、生物法、化学法,评述了各自的优缺点。 相似文献
189.
The mechanism of health effects caused by organohalogen pollutants, e.g., toxins from electronic waste (e-waste), is poorly understood. We supposed that microRNAs (miRNAs), an important post-transcriptional regulator, could play a role in this process. In this study, fasting peripheral blood samples were collected from residents living at an e-waste site in northern China and a nearby reference population. Concentrations of e-waste related organohalogen pollutants in plasma from the exposure group were higher than the corresponding measurement in the reference group. Correspondingly, sixty miRNAs in plasma showed > 2-fold change between the two groups in microarray analysis. Among them, miR-125a-5p was confirmed to be upregulated by qRT-PCR and its validated targets were enriched in responses to xenobiotics and cancer related pathways. Furthermore, significant positive correlations were found between levels of miR-125a-5p in plasma and reactive oxygen species (ROS) in polymorphonuclear neutrophil leukocytes (P < 0.05). These evidences suggested oxidative stress might be an intermediate between e-waste related POPs exposure and alteration of plasma miRNA. 相似文献
190.
附载二氧化钛光催化降解水中对氯苯胺(PCA) 总被引:20,自引:1,他引:19
以紫外灯为光源 ,附载在镍网上的 TiO2 为催化剂 ,研究水中 PCA光催化降解动力学行为和机理 .结果表明 ,PCA的降解符合准一级动力学方程 ;初始 pH4~11对其反应速率影响较小 ;增大氧气浓度能加快 PCA的降解和脱氯速率 ;外加电位能大幅度提高 PCA的降解速率 .通过 GC-MS技术确定其降解中间产物主要有苯胺、硝基苯、对氯硝基苯、偶氮苯、4,4′-二氯偶氮苯等 ,它们最终矿化为 NHp>+ p>4、Clp>- p>、NOp>- p>3 和 CO2 .光催化能有效地降解 PCA但其矿化比降解需要更长的时间 . 相似文献