全文获取类型
收费全文 | 1291篇 |
免费 | 54篇 |
国内免费 | 315篇 |
专业分类
安全科学 | 70篇 |
废物处理 | 69篇 |
环保管理 | 139篇 |
综合类 | 570篇 |
基础理论 | 266篇 |
污染及防治 | 409篇 |
评价与监测 | 64篇 |
社会与环境 | 46篇 |
灾害及防治 | 27篇 |
出版年
2023年 | 11篇 |
2022年 | 57篇 |
2021年 | 37篇 |
2020年 | 26篇 |
2019年 | 27篇 |
2018年 | 37篇 |
2017年 | 56篇 |
2016年 | 52篇 |
2015年 | 45篇 |
2014年 | 80篇 |
2013年 | 142篇 |
2012年 | 109篇 |
2011年 | 86篇 |
2010年 | 63篇 |
2009年 | 76篇 |
2008年 | 100篇 |
2007年 | 70篇 |
2006年 | 90篇 |
2005年 | 39篇 |
2004年 | 33篇 |
2003年 | 45篇 |
2002年 | 41篇 |
2001年 | 29篇 |
2000年 | 29篇 |
1999年 | 36篇 |
1998年 | 31篇 |
1997年 | 27篇 |
1996年 | 23篇 |
1995年 | 28篇 |
1994年 | 15篇 |
1993年 | 19篇 |
1992年 | 24篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1975年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1660条查询结果,搜索用时 62 毫秒
231.
In the present study, a hydrophilic bifunctional polymeric resin (LS-2) with sulfonic groups was synthesized, and the adsorption performance of three aniline compounds, aniline, 4-methylaniline, and 4-nitroaniline onto LS-2 was compared with that on the commercial Amberlite XAD-4. The uptake of the aniline compounds on LS-2 is a procedure of coexistence of physisorption and chemisorption and obeys the pseudo-second order rate equation, while the uptake of the compounds on XAD-4 is merely a physical adsorption and follows the pseudo-first order rate equation. All the isothermal data fit well with the Freundlich model, and the values of K(F) of the compounds adsorbing on LS-2 are much higher than those on XAD-4 suggesting the higher adsorbing capacities on LS-2 than those on XAD-4, which may be attributed to the microporous structure and the polar groups on the network of LS-2 resin. Dynamic adsorption and desorption studies for aniline on LS-2 show that the breakthrough adsorption capacity and the total adsorption capacity are 0.96 and 1.24 mmol per milliliter resin, respectively. Nearly 100% regeneration efficiency for the adsorbent was achieved by 5% hydrochloric acid. 相似文献
232.
Estrogenicity and acute toxicity of selected anilines using a recombinant yeast assay 总被引:3,自引:0,他引:3
Suspected estrogen modulators include industrial organic chemicals (i.e., xenoestrogens), and have been shown to consist of alkylphenols, bisphenols, biphenylols, and some hydroxy-substituted polycyclic aromatic hydrocarbons. The most prominent structural feature identified to be important for estrogenic activity is a polar group capable of donating hydrogen bonds (i.e., hydroxyl) on an aromatic system. The present study was undertaken to explore the estrogenic activity and acute toxicity of chemicals containing a weaker hydrogen bond donor group on aromatic systems, i.e., the amino substituent. There is a great deal of chemical similarity between aromatic amines (anilines) and aromatic alcohols (phenols). The chemicals chosen for the current study contained an amino-substituted benzene ring with hydrophobic constituents varying in size and shape. Thus, 37 substituted aromatic amines were assayed for estrogenic activity EC50 and acute toxicity LC50 using the Saccharomyces cerevisiae recombinant yeast assay. While the EC50 of 17-beta-estradiol occurs at the 10(-10) range, the aniline with the greatest activity had an EC50 of 10(-6) M. Thus, anilines, in general, are capable only of very weak estrogenic activity in this assay. A comparison of estrogenic potency between the present group of anilines and a set of previously tested analogous phenols indicated that anilines are consistently less estrogenic than phenols. A comparison of hazard indices (EC50/LC50) of these chemicals revealed that, for the vast majority of anilines, the EC50 and LC50 were in the same order of magnitude. More specifically, estrogenic activity of para-substituted alkylanilines increases with alkyl group size up to 5 carbons in length, after which the acute toxicity of the larger alkyl-substituents precluded the ability of the compound to induce the estrogenic response. 相似文献
233.
Ott WR Klepeis NE Switzer P 《Journal of the Air & Waste Management Association (1995)》2003,53(8):918-936
This paper derives the analytical solutions to multi-compartment indoor air quality models for predicting indoor air pollutant concentrations in the home and evaluates the solutions using experimental measurements in the rooms of a single-story residence. The model uses Laplace transform methods to solve the mass balance equations for two interconnected compartments, obtaining analytical solutions that can be applied without a computer. Environmental tobacco smoke (ETS) sources such as the cigarette typically emit pollutants for relatively short times (7-11 min) and are represented mathematically by a "rectangular" source emission time function, or approximated by a short-duration source called an "impulse" time function. Other time-varying indoor sources also can be represented by Laplace transforms. The two-compartment model is more complicated than the single-compartment model and has more parameters, including the cigarette or combustion source emission rate as a function of time, room volumes, compartmental air change rates, and interzonal air flow factors expressed as dimensionless ratios. This paper provides analytical solutions for the impulse, step (Heaviside), and rectangular source emission time functions. It evaluates the indoor model in an unoccupied two-bedroom home using cigars and cigarettes as sources with continuous measurements of carbon monoxide (CO), respirable suspended particles (RSP), and particulate polycyclic aromatic hydrocarbons (PPAH). Fine particle mass concentrations (RSP or PM3.5) are measured using real-time monitors. In our experiments, simultaneous measurements of concentrations at three heights in a bedroom confirm an important assumption of the model-spatial uniformity of mixing. The parameter values of the two-compartment model were obtained using a "grid search" optimization method, and the predicted solutions agreed well with the measured concentration time series in the rooms of the home. The door and window positions in each room had considerable effect on the pollutant concentrations observed in the home. Because of the small volumes and low air change rates of most homes, indoor pollutant concentrations from smoking activity in a home can be very high and can persist at measurable levels indoors for many hours. 相似文献
234.
介绍了一种电除尘器脉冲供电的基本原理及其在锌沸腾炉电除尘器上的应用试验情况。结果表明,在基本保持同一工况条件下,脉冲供电比直流供电降低出口烟气含尘浓度50.4%~79.6%;脉冲供电能改善电除尘器运行性能,提高电除尘器改善系数达1.32;脉冲供电运行安全可靠。 相似文献
235.
研究了用Fenton试剂处理选矿废水中残余的黄药,分别考查了氧化时间、反应初始pH值、Fe2+浓度及H2O2用量对黄药降解效果的影响,用正交试验确定了4个因素的最好条件。结果表明:初始pH值和H2O2用量是影响去除效果的主要因素;氧化时间为60 m in,反应初始pH=4,[Fe2+]=20 mg/L,[H2O2]=20 mg/L,黄药的浓度为125 mg/L时,黄药的去除率达到99.5%;初步探讨了Fenton试剂净化废水中黄药的机理是.OH自由基先将黄药氧化为过氧化黄原酸盐,再将其氧化为CO2,黄药得到去除。 相似文献
236.
介绍了氧化铁黄生产中的废水治理情况,同时其产生的废渣可回收利用。经过治理产生的环境、经济和社会效益显著。 相似文献
237.
238.
239.
240.
各种影响因子对电解法预处理医药废水的影响研究 总被引:2,自引:0,他引:2
探讨了电解法预处理医药废水时停留时间、电解电压、废水初始浓度、温度和废水pH值等影响因子对去除色度、COD和提高废水可生化性等处理效果的影响,并考察了其应用于工业实际废水处理的可行性。实验结果表明:电解法更适合高浓度医药废水的处理,色度的去除率可达到90%以上;电解时间宜控制在40-60min;电解电压越高,废水COD和色度去除效果越好;在实验温度范围内,温度对色度和COD去除率的影响不大;废水pH值为7.5时电解效果最佳,工程运用宜控制在6—9之间。 相似文献