全文获取类型
收费全文 | 549篇 |
免费 | 55篇 |
国内免费 | 215篇 |
专业分类
安全科学 | 47篇 |
废物处理 | 21篇 |
环保管理 | 108篇 |
综合类 | 355篇 |
基础理论 | 108篇 |
污染及防治 | 110篇 |
评价与监测 | 33篇 |
社会与环境 | 35篇 |
灾害及防治 | 2篇 |
出版年
2024年 | 6篇 |
2023年 | 15篇 |
2022年 | 24篇 |
2021年 | 42篇 |
2020年 | 24篇 |
2019年 | 17篇 |
2018年 | 28篇 |
2017年 | 25篇 |
2016年 | 34篇 |
2015年 | 31篇 |
2014年 | 42篇 |
2013年 | 85篇 |
2012年 | 50篇 |
2011年 | 53篇 |
2010年 | 32篇 |
2009年 | 38篇 |
2008年 | 29篇 |
2007年 | 42篇 |
2006年 | 35篇 |
2005年 | 23篇 |
2004年 | 28篇 |
2003年 | 22篇 |
2002年 | 18篇 |
2001年 | 17篇 |
2000年 | 11篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1979年 | 1篇 |
排序方式: 共有819条查询结果,搜索用时 234 毫秒
191.
Yi H. Liu Jian Chen Yi R. Guo Chun M. Wang Xiao Liang Guo N. Zhu 《Journal of environmental science and health. Part. B》2013,48(4):313-320
A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC50 and IC10 of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos. 相似文献
192.
193.
Gülden Z. Omurtag Duygu Yazicioğlu 《Journal of environmental science and health. Part. B》2013,48(6):797-807
Abstract The purpose of this study was to investigate the T‐2 toxin contaminated grain and grain products consumed especially by Turkish population. The T‐2 toxin was detected using the high performance liquid chromatography (HPLC) with UV detector at 208 nm and the identify of T‐2 was further confirmed by thin layer chromatography (TLC). The recovery was 91 ±4.24% for corn flour fortified with the known amount of T‐2 toxin (1 ppm). The detection limits of T‐2 toxin for the HPLC and the TLC were 25 ng and 50 ng, respectively. A total of 30 commercially available grain and grain product samples were analyzed. Two corn flour samples were found to contain detectable levels of T‐2 toxin at a level of 1.60 ppm and 4.08 ppm. 相似文献
194.
环境保护产品认证在我国的发展概况 总被引:1,自引:0,他引:1
本文介绍了环境保护产品的概念、特点及其认证范围,论述了环境保护产品认证在我国的发展与目前认证中存在的问题。 相似文献
195.
四川参与性体育旅游产品的创新开发 总被引:9,自引:0,他引:9
体育旅游产品体系庞大,能满足不同类型、不同层次旅游者的需要,具有较强的生命力.由于体育旅游产品深受大众喜爱,具有巨大的市场潜力和可观的经济效益,因此开发体育旅游产品是促进四川旅游业走向强大的重要战略.针对四川参与性体育旅游产品开发的问题以及发展体育旅游的条件,提出了创新开发四川参与性体育旅游产品的途径:①与其它类型的旅游产品有机结合,开发组合性体育旅游产品;②开发少数民族体育旅游资源;③深度开发著名景区的体育旅游资源. 相似文献
196.
Solid phase microextraction (SPME) as an effective means to isolate degradation products in polymers 总被引:2,自引:0,他引:2
Minna Hakkarainen Ann- Christine Albertsson Sigbritt Karlsson 《Journal of Polymers and the Environment》1997,5(2):67-73
A new sample preparation technique, solid phase microextraction (SPME), was compared with direct headspace-GC-MS with respect
to the type and amount of identified compounds. Three types of LDPE films containing photosensitising additives according
to the Scott-Gilead patents and pure LDPE were used as model substances. The polyethylene films were thermally aged at 80‡C
after the induction period was surpassed by subjecting the materials to 100 h of UV radiation. The new SPME method was developed
using nonpolar poly(dimethylsiloxane) and polar carbowax fibers to extract the low molecular weight products formed in the
polyethylene films during aging. Many more products were identified after SPME followed by GC-MS than after direct headspace-GC-MS
of the samples. The SPME method allowed the identification of homologous series of carboxylic acids, ketones, and furanones,
while direct headspace-GC-MS identified only a few carboxylic acids (C1-C6) and small amounts of some ketones and furanones.
In general, SPME was more effective in extracting less volatile products, and in particular, the polar carbowax fiber identified
also C7-C12 carboxylic acids and 4-oxopentanoic acid. By SEC and FTIR we confirmed that the number and amount of former degradation
products correlated well with the decrease in molecular weights and the amount of formed carbonyl compounds. 相似文献
197.
Honeybees and their products as potential bioindicators of heavy metals contamination 总被引:3,自引:0,他引:3
The concentrations of three representative heavy metals(cadmium, chromium and lead) were measured by atomic absorptionspectroscopy in honeybees and in apiary's products (honey,pollen, propolis, and wax). Samples were collected from fivedifferent sampling points: four from areas surrounding the cityof Rome, and the fifth in the city center which receives intensevehicular traffic. All apiaries employed for this study werespecifically constructed without any metal part in order toavoid the risk of contamination of the assayed materials.Sample collection was conducted over a 3-month period (6samplings for honey and pollen, 3 sampling for propolis and wax,2 samplings for honeybees, all of which were collected in duplicate). Experimental data revealed, in general,statistically significant differences between the backgroundlevels of heavy metals recorded from the reference sites and thelevels measured in the site located in the center of the city ofRome.These results indicate that honeybees and, to a lesser extent,some of their products (pollen, propolis, wax, but not honey),can be considered representative bioindicators of environmentalpollution. 相似文献
198.
SAGAR V. KRUPA 《Environmental monitoring and assessment》1997,46(1-2):73-88
Our knowledge of global climate change has many uncertainties.Whether global air temperature will increase, by how much, and when,are subject to debate, but there is little doubt that troposphericconcentrations of several trace gases are increasing. While possibleincreases in the average air temperature is a product of these changes,the increases in the trace gases alone will have an effect on agriculture.Increases in the ambient concentrations of carbon dioxide are expectedto have a positive net effect on crop production. In contrast, anyincreases in the penetration of surface-level ultraviolet-B (280–320 nm)radiation, and known increases in surface ozone concentrations, areconsidered to have adverse effects on certain crops. Our presentknowledge of the joint effects on crops of elevated levels of carbondioxide, ultraviolet-B radiation and ozone, and possible alterations in airtemperature and precipitation patterns, is virtually zero. Therefore, anypredictions of the effects of global climate change on agriculture aresubject to significant uncertainties. In contrast, coupling of climatechange (only temperature and precipitation) models to crop productionhas led to a number of future scenarios. In spite of theirpresent limitations, results from these efforts can be useful in planningfor future agriculture. 相似文献
199.
200.
The Impact of NTFP Sales on Rural Households’ Cash Income in India’s Dry Deciduous Forest 总被引:1,自引:1,他引:1
In recent years, researchers and policy makers have recognized that nontimber forest products (NTFPs) extracted from forests by rural people can make a significant contribution to their well-being and to the local economy. This study presents and discusses data that describe the contribution of NTFPs to cash income in the dry deciduous forests of Orissa and Jharkhand, India. In its focus on cash income, this study sheds light on how the sale of NTFPs and products that use NTFPs as inputs contribute to the rural economy. From analysis of a unique data set that was collected over the course of a year, the study finds that the contribution of NTFPs to cash income varies across ecological settings, seasons, income level, and caste. Such variation should inform where and when to apply NTFP forest access and management policies. 相似文献