全文获取类型
收费全文 | 610篇 |
免费 | 77篇 |
国内免费 | 390篇 |
专业分类
安全科学 | 26篇 |
废物处理 | 27篇 |
环保管理 | 69篇 |
综合类 | 572篇 |
基础理论 | 224篇 |
污染及防治 | 133篇 |
评价与监测 | 13篇 |
社会与环境 | 10篇 |
灾害及防治 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 18篇 |
2021年 | 27篇 |
2020年 | 27篇 |
2019年 | 32篇 |
2018年 | 38篇 |
2017年 | 48篇 |
2016年 | 44篇 |
2015年 | 55篇 |
2014年 | 40篇 |
2013年 | 86篇 |
2012年 | 75篇 |
2011年 | 48篇 |
2010年 | 51篇 |
2009年 | 61篇 |
2008年 | 35篇 |
2007年 | 54篇 |
2006年 | 50篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 35篇 |
2002年 | 19篇 |
2001年 | 30篇 |
2000年 | 23篇 |
1999年 | 14篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 10篇 |
1995年 | 10篇 |
1994年 | 6篇 |
1993年 | 12篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 7篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有1077条查询结果,搜索用时 32 毫秒
71.
为了提高厌氧流化床微生物燃料电池(AFB-MFC)的性能,并为双室MFC寻找价廉、易得、无污染的阴极液,在曝气量16~24 L/h、温度(35±2)℃、回流量10.2 L/h、阴极底边距阴极室内底部17.3 cm、外电阻250 Ω、水力停留时间(HRT)14.0~14.9 h以及进水pH 7.81~8.37下,研究了阴极液及底物浓度对系统产电及废水处理性能的影响。结果表明,使用缓冲溶液、阳极室出水和自来水作阴极液时,自来水的产电性能最佳,阴极液种类不影响系统有机基质的去除。以自来水为阴极液时,阴极液pH及电导率随运行时间增加而增加,COD去除率为80.11%~89.29%,输出电压及功率密度开始随运行时间增加而增加,之后稳定在440~452 mV和48.40~51.08 mW/m2之间。增加底物浓度对COD去除率影响不大,而输出电压及功率密度随底物浓度增加而下降;底物COD浓度由3 307.09 mg/L增至9 520 mg/L时,COD去除率在85.77%~94.44%之间,输出电压及功率密度则分别由449 mV和50.40 mW/m2下降至406 mV和41.21 mW/m2。自来水作阴极液可避免二次污染及阴极液对阳极室微生物的影响,并得到高的产电能力。 相似文献
72.
为考察较低温度(<17℃)条件下添加微量金属元素对厌氧发酵产气量的影响,在发酵底物TS(含固率)为10%下采用10 L玻璃瓶作反应器,以牛粪为原料,向厌氧生物反应器中分别添加MnSO4、FeSO4·7H2O、电解锰渣,分析了厌氧消化系统运行过程中的产气量、COD(化学需氧量)和pH的变化。结果表明,锰元素能促进低温下牛粪的厌氧发酵,加速反应启动。当添加6 g MnSO4、100 g电解锰渣时,单位质量VS产气率分别为0.26 mL/g和0.64 mL/g,添加6 g FeSO4·7H2O与空白对照组均未见明显产气。 相似文献
73.
74.
《Journal of environmental science and health. Part. B》2013,48(4):533-549
Abstract The biotransformation of the nonylphenol isomer [ring-U-14C]-4-(3′,5′-dimethyl-3′-heptyl)-phenol (4-353-NP, consisting of two diastereomers) was studied in soybean and Agrostemma githago cell suspension cultures. With the A. githago cells, a batch two-liquid-phase system (medium/n-hexadecane 200:1, v/v) was used, in order to produce higher concentrations and amounts of 4-353-NP metabolites for their identification; 4-353-NP was applied via the n-hexadecane phase. Initial concentrations of [14C]-4-353-NP were 1 mg L?1 (soybean), and 5 and 10 mg L?1 (A. githago). After 2 (soybean) and 7 days (A. githago) of incubation, the applied 4-353-NP was transformed almost completely by both plant species to four types of products: glycosides of parent 4-353-NP, glycosides of primary 4-353-NP metabolites, nonextractable residues and unknown, possibly polymeric materials detected in the media. The latter two products emerged especially in soybean cultures. Portions of primary metabolites amounted to 19–22% (soybean) and 21–42% of applied 14C (A. githago). After liberation from their glycosides, the primary 4-353-NP metabolites formed by A. githago were isolated by HPLC and examined by GC-EIMS as trimethylsilyl derivatives. In the chromatograms, eight peaks were detected which due to their mass spectra, could be traced back to 4-353-NP. Seven of the compounds were side-chain monohydroxylated 4-353-NP metabolites, while the remaining was a (side-chain) carboxylic acid derivative. Unequivocal identification of the sites of hydroxylation/oxidation of all transformation products was not possible. The main primary metabolites produced by A. githago were supposed to be four diastereomers of 6′-hydroxy-4-353-NP (about 80% of all products identified). It was concluded that plants contribute to the environmental degradation of the xenoestrogen nonylphenol; the toxicological properties of side-chain hydroxylated nonylphenols remain to be examined. 相似文献
75.
Vera Garaj-Vrhovac Višnja Oreščanin Goran Gajski Marko Gerić Damir Ruk Robert Kollar Sandra Radić Brkanac Petra Cvjetko 《Chemosphere》2013
In this research, toxicological safety of two newly developed methods for the treatment of landfill leachate from the Piškornica (Croatia) sanitary landfill was investigated. Chemical treatment procedure combined chemical precipitation with CaO followed by coagulation with ferric chloride and final adsorption by clinoptilolite. Electrochemical treatment approach included pretreatment with ozone followed by electrooxidation/electrocoagulation and final polishing by microwave irradiation. Cell viability of untreated/treated landfill leachate was examined using fluorescence microscopy. Cytotoxic effect of the original leachate was obtained for both exposure periods (4 and 24 h) while treated samples showed no cytotoxic effect even after prolonged exposure time. The potential DNA damage of the untreated/treated landfill leachate was evaluated by the comet assay and cytokinesis-block micronucleus (CBMN) assay using either human or plant cells. The original leachate exhibited significantly higher comet assay parameters compared to negative control after 24 h exposure. On the contrary, there was no significant difference between negative control and chemically/electrochemically treated leachate for any of the parameters tested. There was also no significant increase in either CBMN assay parameter compared to the negative control following the exposure of the lymphocytes to the chemically or electrochemically treated landfill leachate for both exposure periods while the original sample showed significantly higher number of micronuclei, nucleoplasmic bridges and nuclear buds for both exposure times. Results suggest that both methods are suitable for the treatment of such complex waste effluent due to high removal efficiency of all measured parameters and toxicological safety of the treated effluent. 相似文献
76.
Hu Z 《Chemosphere》2008,72(2):312-318
The biokinetics of attached and suspended bacteria are an essential component of activated sludge models, anaerobic digestion models and biofilm models. These parameters are often assumed or “confirmed” based on the goodness-of-fit of the bioprocess models. Using a microbial fuel cell with a baffled reactor chamber, the attached- and mixed-growth microbial decay coefficients were evaluated under anaerobic conditions. The capability for real-time voltage recording allows easy and accurate measurement of the anaerobic microbial decay coefficients (bL, lysis-regrowth approach), which were determined to be 0.11 ± 0.01 and 0.15 ± 0.01 d−1 for attached (to anode) and mixed (present in the anode chamber) growth microorganisms, respectively. The corresponding half-saturation constants using glucose as a substrate were 204 ± 10 and 123 ± 1 mg COD l−1. Hence, like an oxygen uptake rate-based approach to measure the microbial kinetics under aerobic conditions, the electrochemical recording provides an attractive method to measure anaerobic microbial decay coefficients. 相似文献
77.
78.
Cadmium has been recognized as pollutant of the environment for many years and numerous studies on its toxic effects have been carried out. Little, however, is known about its metabolic behaviour e.g. why the metal is accumulated so extremely rapidly into the organs of men and animals. Since the study of the individual metabolic steps is very difficult in vivo cell cultures may be used to obtain first indications of what happens in the whole animal. We used CHO cells in monolayer culture to study the conditions under which the uptake of cadmium occurs. From serumfree medium the metal is accumulated rapidly in the cells. The uptake is inhibited very strongly by the presence of serum or albumin. Accumulation occurs against a concentration gradient and is dependent on the incubation temperature. Below 10°C no cadmium uptake is seen. Several substances which are known to affect cell metabolism have been used to influence cadmium accumulation. Neither inhibitors of energy production nor microtubule or microfilament disruptors showed any substantial effect. In contrast SH‐group blocking agents markedly reduced cadmium uptake. The results show that cadmium uptake does not occur by passive diffusion but by some active mechanism. 相似文献
79.
采用机械球磨法对膨润土、硅藻土、高岭土3种天然黏土材料进行预处理,通过超声法将纳米TiO_2附着于其上制得复合材料,考察了不同复合材料加入量及养护时间条件下复合材料对电解锰渣中Mn的吸附固定效果。3种天然黏土材料中,硅藻土的平均粒径最小,比表面积和总孔隙度最大,对水中Mn的吸附量也最大。黏土材料附着纳米TiO_2后对电解锰渣中Mn的吸附固定效果较单纯黏土材料有明显改善。在养护时间为12 d、硅藻土附着纳米Ti O_2复合材料加入量为10%(w)的最佳条件下,Mn的TCLP浸出量较原电解锰渣下降了83.04%。 相似文献
80.