全文获取类型
收费全文 | 942篇 |
免费 | 98篇 |
国内免费 | 276篇 |
专业分类
安全科学 | 135篇 |
废物处理 | 74篇 |
环保管理 | 71篇 |
综合类 | 510篇 |
基础理论 | 127篇 |
污染及防治 | 243篇 |
评价与监测 | 145篇 |
社会与环境 | 7篇 |
灾害及防治 | 4篇 |
出版年
2024年 | 10篇 |
2023年 | 22篇 |
2022年 | 41篇 |
2021年 | 34篇 |
2020年 | 39篇 |
2019年 | 28篇 |
2018年 | 31篇 |
2017年 | 47篇 |
2016年 | 59篇 |
2015年 | 63篇 |
2014年 | 76篇 |
2013年 | 125篇 |
2012年 | 88篇 |
2011年 | 85篇 |
2010年 | 46篇 |
2009年 | 48篇 |
2008年 | 43篇 |
2007年 | 54篇 |
2006年 | 66篇 |
2005年 | 39篇 |
2004年 | 31篇 |
2003年 | 37篇 |
2002年 | 30篇 |
2001年 | 32篇 |
2000年 | 25篇 |
1999年 | 24篇 |
1998年 | 28篇 |
1997年 | 21篇 |
1996年 | 13篇 |
1995年 | 3篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1983年 | 1篇 |
排序方式: 共有1316条查询结果,搜索用时 23 毫秒
91.
92.
采用固体平板和液体摇瓶培养方法,研究了赤霉素、2,4-D、吲哚乙酸和萘乙酸4种激素对平菇-126菌丝生长及酶活性的影响。结果表明,吲哚乙酸虽然能提高发酵液胞外蛋白的含量和过氧化物酶活性,但对菌丝的生长起抑制作用,这与吲哚乙酸能引起平菇菌丝裂解和细胞膜渗漏有关;萘乙酸、低浓度2,4-D能促进菌丝的伸长;萘乙酸、赤霉素在低浓度下也能促进菌丝的分枝,对菌丝的生长整体上起促进作用。除吲哚乙酸外,其他3种激素对平菇菌丝生长影响都有两重性:低浓度下能促进菌丝的生长,浓度过高则会对菌丝生长产生毒害作用。 相似文献
93.
Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH3 in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors. 相似文献
94.
Brazil has a great potential for use renewable raw materials in biorefineries. It is one of the largest producers of agricultural and animal commodities, which produce large amounts of residues and wastes. These agricultural residues and animal waste can be effectively transformed to energy and other products in systems similar to a ethanol refinery where an integrated process involves conversion for biomass into fuel, energy and chemicals, integrated in the context of a biorefinery. The objective of this work is the determination of the actual availability of main agricultural residues and animal wastes generated in Brazil and of their generation potential index and their prospects for 2020. The results indicate that the sugarcane has the highest agronomic availability, reaching 157 million tons of fresh material and an estimated reuse potential of 19.6 million tons (dry basis), followed by soybeans, rice, maize, orange, wheat, cotton, cassava and tobacco. 相似文献
95.
马建华 《中国环境管理干部学院学报》2005,15(1):38-41
采用顶空气相色谱法测定食品中甜蜜素含量,探讨了气液相平衡条件及色谱条件的选择,实验结果表明甜蜜素的标准溶液在0.1-0.4μg/l范围内具有良好的线性关系,回收率为87.5%-101.8%,相对标准偏差为2.6%. 相似文献
96.
地面水中叶枯灵的高效液相色谱测定 总被引:2,自引:0,他引:2
本文采用反相高效液相色谱法,在质控条件下,对河水,塘水两种地面水中叶枯灵的检验方法进行了测试,用Shimapck ODS柱为分析柱,以甲醇:水=50:50为流动相,并用冰醋酸调PH至4-5,紫外检测波长281nm,两种水样的平均回收率分别为91.7-96.3%,90-95.8%,相对标准偏差为4.3%,最低检出限为0.0261mg/l,为地面水中叶枯灵卫生标准的实施提供了简便,灵敏,正确的配套测试手段。 相似文献
97.
环境水样阴离子表面活性剂光度测定法 总被引:2,自引:0,他引:2
杨四海 《中国环境管理干部学院学报》1999,(4)
本文通过实验研究,提出了对河水及生活废水阴离子表面活性剂的水相直接测定方法,此方法具有简便、快速的特点,且有良好的准确性和再现性。 相似文献
98.
高浓度酒精糟液经厌氧生物处理后排出的消化液COD浓度为4500—6000mg/L,SS浓度高这1500—2.600mg,/L,且由于微小沼气泡附着在厌氧污泥上,沉降性能很差,难以与消化液相分离,对后续处理十分不剁。本研兜采用预曝气.化学混凝沉淀组合工艺,对该消化液进行去除高浓度SS的顸处理试验,研究探讨了曝气时间、混凝剂种类和投加量对SS和COD去除效果的影响。试验结果表明,预曝气.化学混凝沉淀组合工艺对消化液SS的去除效果十分显著。当预曝气时间为6.0h,FeCl3投加量为100mg/L时,消化液的SS去除率75.4%,COD去除率24.3%,可为后续的好氧生物处理提供较为有利的水质和负荷条件。 相似文献
99.
A. A. Al‐Mihanna A.K. Salama M.Y. Abdalla 《Journal of environmental science and health. Part. B》2013,48(6):693-704
Abstract Biodegradation of chlorpyrifos was studied in liquid culture media amended with either single or combined eight different plant pathogenic fungi isolated from the continuous cropping wheat fields. The average recovery of chlorpyrifos from the liquid media was found to be 86.1%. The detection limit of chlorpyrifos by the analytical method used was 19 ppb. Data showed that the growth of mixed fungi at concentrations up to 200 ppm of chlorpyrifos was higher than in the control treatment. Chlorpyrifos concentrations declined in the medium of combined fungi more than it did in the medium of any single fungus with increase in the incubation period. The amount of chlorpyrifos recovered was 79.8 ppm (39.9%) in the combined fungal cultures after 21 days. However, those recovered from the media of Fusarium graminearum, F. oxysporum, Rhizoctonia solani, Cladosporhim cladosporiodes, Cephalosporium sp., Trichoderma viridi, Alternaria alternata, and Cladorrhinum brunnescens, ranged from 48.0 to 74.8%. The half‐life value (T1/2) for chlorpynfos was 15.8 day in the medium amended with mixed fungi. However, for the single cultures it ranged from 19.3 to 33.0 day. 相似文献
100.
Paula Paíga Kaline Amaral Wanderley Severino Alves Júnior C.M. Delerue-Matos 《毒物与环境化学》2015,97(6):687-699
Carbamate compounds are an important group of cholinesterase inhibitors. There is a need for creating awareness regarding the risks of the inadequate carbamate use in the residential areas due to potential adverse human effects. Carbaryl is a commonly used pesticide worldwide. A simple, fast, and high-throughput method was developed employing liquid chromatography with fluorescence detector to determine carbaryl residues in rat feces. The extraction was performed by using a rapid, easy, cheap, effective, reliable, and safe (QuEChERS) method, using acetonitrile as the extracting solvent. The parameters for the performance of the extraction method were optimized, such as ratio of mass of sample per volume of extraction solvent, QuEChERS content, and cleanup columns. Linear response was obtained for all calibration curves (solvent and matrix-matched) over the established concentration range (5–500 μg/L) with a correlation coefficients higher than 0.999. The achieved recovery was 97.9% with relative standard deviation values of 1.1% (n = 4) at 167 μg/kg fortified concentration level and the limits of detection and quantification were 27.7 and 92.3 µg/kg, respectively. 相似文献