全文获取类型
收费全文 | 250篇 |
免费 | 25篇 |
国内免费 | 71篇 |
专业分类
安全科学 | 17篇 |
废物处理 | 13篇 |
环保管理 | 36篇 |
综合类 | 160篇 |
基础理论 | 15篇 |
污染及防治 | 62篇 |
评价与监测 | 38篇 |
社会与环境 | 1篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 5篇 |
2017年 | 10篇 |
2016年 | 21篇 |
2015年 | 15篇 |
2014年 | 26篇 |
2013年 | 39篇 |
2012年 | 24篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 19篇 |
2008年 | 20篇 |
2007年 | 19篇 |
2006年 | 12篇 |
2005年 | 8篇 |
2004年 | 6篇 |
2003年 | 10篇 |
2002年 | 16篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 2篇 |
排序方式: 共有346条查询结果,搜索用时 281 毫秒
41.
42.
节水灌溉与控释肥施用对太湖地区稻田土壤氮素渗漏流失的影响 总被引:6,自引:0,他引:6
在太湖流域采用田间小区试验研究了干湿交替节水灌溉与控释肥(控释BB肥与树脂包膜尿素)施用对稻田30 cm深土壤渗漏水总氮(TN)、铵态氮(NH+4-N)、硝态氮(NO-3-N)和亚硝态氮(NO-2-N)浓度的动态变化及氮素淋失的影响.结果表明:各处理渗漏水TN、NH+4-N和NO-2-N浓度均在施肥后10 d内达到高峰,然后逐渐下降.渗漏水氮素以NH+4-N(0.22~15.15 mg·L-1)为主,平均占TN 70.1%,NO-3-N(0.10~0.95 mg·L-1)占TN比例较低,平均为13.0%,NO-2-N(0~0.24 mg·L-1)平均仅占TN 1.3%.与淹灌相比,节灌对稻田渗漏水氮素浓度及各氮素占总氮的比例影响不大,但降低了14.2%的渗漏水量和9.4%的TN淋失量.施氮显著提高了渗漏水氮素浓度以及NH+4-N和NO-2-N占TN的比例.控释BB肥和树脂包膜尿素较常规尿素处理水稻全生育期渗漏水TN平均浓度分别降低10.2%和43.3%,TN淋失量分别降低26.1%和39.5%.综上,干湿交替节灌结合树脂包膜尿素施用有利于降低氮素渗漏损失,促进农田面源污染减排. 相似文献
43.
A rapid and simple method for determination of persulfate in aqueous solution was developed. The method is based on the rapid reaction of persulfate with Methylene Blue(MB) via domestic microwave activation, which can promote the activation of persulfate and decolorize MB quickly. The depletion of MB at 644 nm(the maximum absorption wavelength of MB) is in proportion to the increasing concentration of persulfate in aqueous solution. Linear calibration curve was obtained in the range 0–1.5 mmol/L, with a limit of detection of 0.0028 mmol/L. The reaction time is rapid(within 60 sec), which is much shorter than that used for conventional methods. Compared with existing analytical methods, it need not any additives, especially colorful Fe2+, and need not any pretreatment for samples, such as p H adjustment. 相似文献
44.
Houyu Wang Chun-Gang Yuan Chenchen Liu Xuelei Duan Qi Guo Yiwen Shen Jingfu Liu Yongsheng Chen 《环境科学学报(英文版)》2022,34(5):286-293
The creation of an environmentally friendly synthesis method for silver nanomaterials (AgNPs) is an urgent concern for sustainable nanotechnology development. In the present study, a novel straightforward and green method for the preparation of silver nanoparticle/reduced graphene oxide (AgNP/rGO) composites was successfully developed through the combination of phytosynthesis, continuous flow synthesis and microwave-assistance. Oriental persimmon (Diospyros kaki Thunb.) extracts were used as both plant reducing and capping agents for fast online synthesis of AgNP/rGO composites. The experimental parameters were optimized and the morphologies of the prepared materials were investigated. The characterization results reveal that spherical AgNPs were quickly synthesized and uniformly dispersed on rGO sheets using the proposed online system. Fourier transform infrared spectroscopy analysis confirmed that phenols, flavonoids, and other substances in the plant extracts played a decisive role in the synthesis of AgNP/rGO composites. Using sodium borohydride (NaBH4) degradation of p-nitrophenol (4-NP) as a model, the catalytic activity of the prepared AgNP/rGO materials was evaluated. The complete degradation of 4-NP was achieved within 12 min through the use of AgNP/rGO materials, and the composite had a much better catalytic activity than the bare AgNPs and rGO had. Compared with the conventional chemical method, our online method is facile, fast, cost-efficient, and environmentally friendly. 相似文献
45.
畜禽粪便除臭及生物干燥技术研究进展 总被引:5,自引:0,他引:5
综述了近几年来国内外畜禽粪便除臭及脱水技术的研究进展,其中对生物干燥技术的发展进行了比较详细的介绍,以期推动我国畜禽粪便处理技术水平的提高。 相似文献
46.
47.
微波萃取技术在分析土壤中有机污染物的应用 总被引:13,自引:0,他引:13
介绍了微波萃取技术及其使用的试剂、设备和条件,对微波萃取在分析土壤中有机污染物的应用予以综述,阐述了微波萃取技术是分析土壤中有机污染物的好方法。 相似文献
48.
49.
采用以硫酸亚铁(FeSO4)为主要成分的复合脱水剂作为疏浚泥浆脱水剂(以下简称脱水剂),黄沙、炉渣、煤灰、石灰和粉煤灰分别作为疏浚底泥干化改良剂进行实验研究。结果表明,在脱水剂投加量为100 mg/L条件下,可以提高沉淀效率约20%;在投加脱水剂及5%石灰、粉煤灰、炉渣改良剂的条件下,底泥比阻值下降50%~70%;初期渗水速率提高6%~68%;与原泥相比,以黄沙、炉渣、煤灰为改良剂的底泥,经过4个月干化期后,承载力提高了30%~150%。本研究为疏浚底泥快速脱水干化提供了一种可行的技术途径。 相似文献
50.
Kwang V. Lo Winnie W. I. Chan Selina K. Yawson Ping H. Liao 《Journal of environmental science and health. Part. B》2013,48(4):362-367
This study investigated the treatment of dairy manure using the microwave enhanced advanced oxidation process (MW-AOP) at pH 2. An experimental design was developed based on a statistical program using response surface methodology to explore the effects of temperature, hydrogen peroxide dosage and heating time on sugar production, nutrient release and solids destruction. Temperature, hydrogen peroxide dosage and acid concentration were key factors affecting reducing sugar production. The highest reducing sugar yield of 7.4% was obtained at 160°C, 0 mL, 15 min heating time, and no H2O2 addition. Temperature was a dominant factor for an increase of soluble chemical oxygen demand (SCOD) in the treated dairy manure. The important factors for volatile fatty acids (VFA) production were microwave temperature and hydrogen peroxide dosage. Temperature was the most important parameter, and heating time, to a lesser extent affecting orthophosphate release. Heating time, hydrogen peroxide dosage and temperature were significant factors for ammonia release. There was a maximum of 96% and 196% increase in orthophosphate and ammonia concentration, respectively at 160°C, 0.5 mL H2O2 and 15 min heating time. The MW-AOP is an effective method in dairy manure treatment for sugar production, nutrient solubilisation, and solids disintegration. 相似文献