全文获取类型
收费全文 | 1602篇 |
免费 | 67篇 |
国内免费 | 485篇 |
专业分类
安全科学 | 87篇 |
废物处理 | 109篇 |
环保管理 | 128篇 |
综合类 | 794篇 |
基础理论 | 290篇 |
污染及防治 | 539篇 |
评价与监测 | 81篇 |
社会与环境 | 68篇 |
灾害及防治 | 58篇 |
出版年
2024年 | 1篇 |
2023年 | 16篇 |
2022年 | 69篇 |
2021年 | 54篇 |
2020年 | 40篇 |
2019年 | 45篇 |
2018年 | 60篇 |
2017年 | 60篇 |
2016年 | 65篇 |
2015年 | 74篇 |
2014年 | 104篇 |
2013年 | 135篇 |
2012年 | 130篇 |
2011年 | 135篇 |
2010年 | 101篇 |
2009年 | 88篇 |
2008年 | 72篇 |
2007年 | 80篇 |
2006年 | 90篇 |
2005年 | 65篇 |
2004年 | 64篇 |
2003年 | 62篇 |
2002年 | 46篇 |
2001年 | 51篇 |
2000年 | 65篇 |
1999年 | 52篇 |
1998年 | 56篇 |
1997年 | 42篇 |
1996年 | 47篇 |
1995年 | 42篇 |
1994年 | 28篇 |
1993年 | 24篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 12篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 12篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1978年 | 4篇 |
排序方式: 共有2154条查询结果,搜索用时 328 毫秒
291.
Osmotic distillation (OD) was found to be a coupled process in membrane absorption (MA) for the treatment of high strength ammonia wastewater. As a result, ammonia could not be concentrated in absorption solution(AS) as expected. The inhibition of the coupled OD in MA process was investigated as well as various factors affecting the inhibition. The results indicated that the coupled OD can be effectively inhibited by heating concentrated solution and cooling dilute solution. It was also found that experimental minimum inhibition temperature difference(MITD) between concentrated and dilute solutions was different when using polyvinylidene fluoride(PVDF) and polypropylene(PP) membranes respectively, which could be ascribed to material properties, such as OD and membrane distillation (MD) coefficients of the membranes. Experimental MITDs were found to be higher than theoretical MITDs which were calculated using a simplified method. 相似文献
292.
The experiments on pollutant movement in surf zone were conducted on the two gentle beaches(with slope of 1:100 and 1:40, respectively), for diverse wave cases. The movement contours and direction of pollutants, under the action of regular and random waves with diverse wave amplitudes, were provided and studied in this paper. It was shown that, due to complicated hydrodynamics in surf zone, the pollutant movement state is quite complicated and different from that in pure current zone. 相似文献
293.
The genetic composition of Poa annua L, populations with a series of traffic pollution was studied by starch electrophoresis. Five enzyme systems were stained. The results showed that: (1) Traffic pollution can dramatically change genotypic frequencies at some loci of P. annua populations. Significant deviations from HardyWeinberg equilibrium were observed on loci Fe - 1 and Me due to the excess of heterozygotes in some populations.(2) The effective number of alleles per locus and the observed and expected heterozygosity were higher in the pollution series than in the clear control site(Botanic Park population), but the increase was not related with the pollution extent. (3) Most genetic variation was found within populations, and only 6.21% was among populations of the polluted series. Slightly higher differentiation( FST = 7.98%) was observed when the control population was included. (4) The calculated gene flow(Nm) is 2.8841 per generation. The mean of genetic identity is 0.9864 and the genetic distance average to 0.0138. 相似文献
294.
沈广义 《中国个体防护装备》2010,(2):27-30
现代高科技武器的发展以及日益复杂的作战环境对防弹衣的防弹性能和穿着舒适性提出了更高要求。新材料仍将成为下一代新型防弹衣的开发方向。本文介绍的碳钠米管纤维早在20世纪90年代就已经被发现。由于其制造成本贵比黄金而一直未被广泛使用。近年来随着工艺技术的改进及生产规模的扩大,碳纳米管的生产成本大幅降低,其开发潜能和应用前景逐渐受到材料科学界和高新技术产业部门的关注。本文在分析现代常用防弹衣防弹机理的基础上着重论述碳钠米管作为超级纤维的独特性能在防弹领域中的应用优势。 相似文献
295.
296.
采集了全国14个稀土施用区3种不同施用条件(土施、喷施、拌种)下的成熟小麦样品及未施用稀土对照样品,利用等离子体质谱法(ICP-MS)测定了小麦植株的根、茎、叶及籽粒中14种稀土元素的含量。分别探讨了不同外源下小麦植株各部位稀土元素的含量及分布特征,并与有关文献中的报道进行了对比。研究结果表明,土施和拌种的小麦各部位没有发现明显残留,施用样各部位稀土总量比对照样增加约5%-10%,其分布模式与土壤类似;喷施的小麦样品的根、茎、叶中稀土残留严重,其含量比对照样高一个数量级,其分布模式与土壤及对照完全不同,表现为轻稀土更富集;3种施用方法的小麦籽粒中稀土残留均不明显。 相似文献
297.
Tao Liu Yudong Song Zhiqiang Shen Yuexi Zhou 《Frontiers of Environmental Science & Engineering》2021,15(6):119
298.
Huachang Hong Qianyun Song Asit Mazumder Qian Luo Jianrong Chen Hongjun Lin Haiying Yu Liguo Shen Yan Liang 《Environmental geochemistry and health》2016,38(6):1303-1312
The purpose of this study was to develop the multiple regression models to evaluate the formation of trihalomethanes (THMs) and haloacetonitriles (HANs) during chlorination of source water with low specific ultraviolet absorbance (SUVA) in Yangtze River Delta, China. The results showed that the regression models of THMs exhibited good accuracy and precision, and 86–97 % of the calculated values fell within ±25 % of the measured values. While the HANs models showed relatively weak evaluation ability, as only 75–83 % of the calculated values were within ±25 % of the measured values. The organic matter [dissolved organic carbon (DOC) or UV absorbance at 254 nm] and bromide exerted the most important influence on the formation of HANs. While for THMs, besides the organic matter and bromide, reaction time was also a key factor. Comparing the models for total THMs (T-THMs) in this study with others revealed that the regression models from the low SUVA waters may have low DOC coefficients, but high bromide coefficients as compared with those from the high SUVA waters. 相似文献
299.
300.
采用批实验研究了蒙脱石对左氧氟沙星的吸附机理及对左氧氟沙星抗菌作用的影响。结果表明,中性条件下存在培养基时,左氧氟沙星在蒙脱石上前2 h即达到吸附平衡,吸附等温线符合Langmuir吸附方程,吸附率达90%以上;蒙脱石吸附左氧氟沙星存在阳离子交换作用、氢键作用、疏水作用、阳离子键桥作用、静电吸附作用等物理化学过程;蒙脱石本身不具有抑菌、杀菌活性,且由于蒙脱石增大了微生物附着的比表面积,在特定情况下可以促进微生物的生长;扣除其对微生物生长的促进作用后,蒙脱石吸附左氧氟沙星降低了后者的毒性效应,其抑菌率降低约25%。上述结果为进一步研究抗生素在环境中的毒理效应提供了基础依据。 相似文献