全文获取类型
收费全文 | 7320篇 |
免费 | 858篇 |
国内免费 | 3582篇 |
专业分类
安全科学 | 513篇 |
废物处理 | 343篇 |
环保管理 | 1003篇 |
综合类 | 5978篇 |
基础理论 | 1405篇 |
环境理论 | 1篇 |
污染及防治 | 1617篇 |
评价与监测 | 519篇 |
社会与环境 | 312篇 |
灾害及防治 | 69篇 |
出版年
2024年 | 13篇 |
2023年 | 133篇 |
2022年 | 244篇 |
2021年 | 321篇 |
2020年 | 268篇 |
2019年 | 343篇 |
2018年 | 366篇 |
2017年 | 359篇 |
2016年 | 458篇 |
2015年 | 479篇 |
2014年 | 570篇 |
2013年 | 702篇 |
2012年 | 760篇 |
2011年 | 804篇 |
2010年 | 621篇 |
2009年 | 789篇 |
2008年 | 479篇 |
2007年 | 534篇 |
2006年 | 579篇 |
2005年 | 484篇 |
2004年 | 339篇 |
2003年 | 339篇 |
2002年 | 290篇 |
2001年 | 251篇 |
2000年 | 225篇 |
1999年 | 190篇 |
1998年 | 142篇 |
1997年 | 125篇 |
1996年 | 121篇 |
1995年 | 122篇 |
1994年 | 70篇 |
1993年 | 57篇 |
1992年 | 57篇 |
1991年 | 33篇 |
1990年 | 23篇 |
1989年 | 8篇 |
1988年 | 12篇 |
1987年 | 12篇 |
1986年 | 7篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 7篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1978年 | 1篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
541.
考察了微波-活性炭联合处理技术对模拟染料废水中亚甲基蓝和Cd2+的去除效果。对于100 mL浓度为1 000 mg/L的亚甲基蓝溶液、活性炭用量为10 g时,新活性炭对亚甲基蓝的去除率为99.99%;采用700 W微波对吸附亚甲基蓝的活性炭辐射10 min进行再生并回用,经微波辐射再生10次后活性炭对亚甲基蓝的去除率为99.68%,未经微波作用反复使用10次的活性炭对亚甲基蓝的去除率为85.41%。结果表明:微波处理有效地减缓了活性炭吸附能力的下降速率,实现了活性炭再生和反复使用。在吸附过程中,Cd2+使活性炭对亚甲基蓝的吸附能力略有下降,而共存的亚甲基蓝则促进了活性炭对Cd2+的吸附,对新炭和再生后活性炭物理化学特性的表征证明了活性炭对亚甲基蓝的吸附为物理吸附,对Cd2+的吸附为化学吸附。 相似文献
542.
Kornelia Zemke Axel Liebscher Maren Wandrey the COSINKGroup 《International Journal of Greenhouse Gas Control》2010,4(6):990-999
To test the injection behaviour of CO2 into brine-saturated rock and to evaluate the dependence of geophysical properties on CO2 injection, flow and exposure experiments with brine and CO2 were performed on sandstone samples of the Stuttgart Formation representing potential reservoir rocks for CO2 storage. The sandstone samples studied are generally fine-grained with porosities between 17 and 32% and permeabilities between 1 and 100 mD.Additional batch experiments were performed to predict the long-term behaviour of geological CO2 storage. Reservoir rock samples were exposed over a period of several months to CO2-saturated reservoir fluid in high-pressure vessels under in situ temperature and pressure conditions. Petrophysical parameters, porosity and the pore radius distribution were investigated before and after the experiments by NMR (Nuclear Magnetic Resonance) relaxation and mercury injection. Most of the NMR measurements of the tested samples showed a slight increase of porosity and a higher proportion of large pores. 相似文献
543.
There is increasing concern that agricultural intensification in China has greatly increased N2O emissions due to rapidly increased fertilizer use. By linking a spatial database of precipitation, synthetic fertilizer N input, cropping rotation and area via GIS, a precipitation-rectified emission factor of N2O for upland croplands and water regime-specific emission factors for irrigated rice paddies were adopted to estimate annual synthetic fertilizer N-induced direct N2O emissions (FIE-N2O) from Chinese croplands during 1980-2000. Annual FIE-N2O was estimated to be 115.7 Gg N2O-N year−1 in the 1980s and 210.5 Gg N2O-N year−1 in the 1990s, with an annual increasing rate of 9.14 Gg N2O-N year−1 over the period 1980-2000. Upland croplands contributed most to the national total of FIE-N2O, accounting for 79% in 1980 and 92% in 2000. Approximately 65% of the FIE-N2O emitted in eastern and southern central China. 相似文献
544.
Arturo Rodríguez-Blanco Virginie Antoine Emilien Pelletier Jean-François Ghiglione 《Environmental pollution (Barking, Essex : 1987)》2010,158(3):663-1031
The dynamics of total and active microbial communities were studied in seawater microcosms amended with crude or diesel oil at different temperatures (25, 10 and 4 °C) in the presence/absence of organic fertilization (Inipol EAP 22). Total and hydrocarbon-degrading microbes were enumerated by fluorescence microscopy and Most Probable Number (MPN) method, respectively. Total (16S rDNA-based) vs. active (16S rRNA) bacterial community structure was monitored by Capillary-Electrophoresis Single Strand Conformation Polymorphism (CE-SSCP) fingerprinting. Hydrocarbons were analyzed after 12 weeks of incubation by gas chromatography-mass spectrometry. Total and hydrocarbon-degrading microbial counts were highly influenced by fertilization while no important differences were observed between temperatures. Higher biodegradation levels were observed in fertilized microcosms. Temperature and fertilization induced changes in structure of total bacterial communities. However, fertilization showed a more important effect on active bacterial structure. The calculation of Simpson's diversity index showed similar trends among temperatures whereas fertilization reduced diversity index of both total and active bacterial communities. 相似文献
545.
Xiaosong Chang Xiaoyun Liu Hao Chen Zhiqun Qiu Jia Cao 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1444-6108
Sewage samples from 4 hospitals, 1 nursery, 1 slaughter house, 1 wastewater treatment plant and 5 source water samples of Chongqing region of Three Gorge Reservoir were analyzed for macrolide, lincosamide, trimethoprim, fluorouinolone, sulfonamide and tetracycline antibiotics by online solid-phase extraction and liquid chromatography-tandem mass spectrometry. Results showed that the concentration of ofloxacin (OFX) in hospital was the highest among all water environments ranged from 1.660 μg/L to 4.240 μg/L and norfloxacin (NOR, 0.136-1.620 μg/L), ciproflaxacin (CIP, ranged from 0.011 μg/L to 0.136 μg/L), trimethoprim (TMP, 0.061-0.174 μg/L) were commonly detected. Removal range of antibiotics in the wastewater treatment plant was 18-100% and the removal ratio of tylosin, oxytetracycline and tetracycline were 100%. Relatively higher removal efficiencies were observed for tylosin (TYL), oxytetracycline (OXY) and tetracycline (TET)(100%), while lower removal efficiencies were observed for Trimethoprim (TMP, 1%), Epi-iso-chlorotetracycline (EICIC, 18%) and Erythromycin-H2O (ERY-H2O, 24%). Antibiotics were removed more efficiently in primary treatment compared with those in secondary treatment. 相似文献
546.
Ruowei Ma 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1354-5700
The study reported in this paper examined the concentrations of nineteen perfluorochemicals (PFCs), including perfluoroalkyl sulfonates, carboxylates, and sulfonamides in samples collected from Hong Kong wastewater treatment plants (WWTPs) and sediments. The study was the first to use an external isolator column to assist in the quantification of PFCs in environmental samples without having to make internal modifications to a liquid chromatography system. Perfluorooctanesulfonate was found to be the dominant PFC pollutant in Hong Kong, and the WWTP sludge was the major sink of PFCs discharged from the urban areas. Compared to discharge influenced by industrial activities, much less perfluorooctanoate was found in waste streams. The significantly lower level of perfluorodecanesulfonate in WWTP sludge reflects the important influence of consumer products on PFC distribution. The dominance of even-chain length perfluoroalkyl carboxylates in all of the WWTP sludge samples investigated further suggests the strong aerobic degradation of fluorotelomer alcohols in WWTPs. 相似文献
547.
Magnus Bergknut Hjalmar Laudon 《Environmental pollution (Barking, Essex : 1987)》2010,158(7):2518-2525
The aim of this study was to explore how atmospherically derived soil pollution is affected by environmental processes at two typical boreal catchment landscape type settings: wetlands and forested areas. Measurements of hydrophobic organic compounds (HOCs) in forest soil and peat from an oligotrophic mire at various depths were performed at a remote boreal catchment in northern Sweden. HOCs in peat were evenly distributed throughout the body of the mire while levels of HOCs in the forest soil increased with increased amount of organic matter. Evaluation of HOC composition by principal component analysis (PCA) showed distinct differences between surface soils and deeper soil and peat samples. This was attributed to vertical transport, degradation and/or shifting sources over time. The calculated net vertical transport differed between surface layers (0.3%) and deeper soils (8.0%), suggesting that vertical transport conditions and processes differ in the deeper layers compared to the surface layers. 相似文献
548.
Francisca F. del Campo 《Environmental pollution (Barking, Essex : 1987)》2010,158(9):2906-108
Microcystins (MCs) are toxic cyclic heptapeptides produced by various cyanobacteria genera, especially Microcystis. We identified 10 out of 12 MCs produced by three Microcystis aeruginosa strains from cyanobacteria collections, UTEX 2666, UTEX 2670 and UAM 1303, by using two analytical methods: Matrix-assisted Laser Desorption Ionization Time of Flight Mass Spectrometry (MALDI-TOF/MS) and HPLC Photodiode Array Detector coupled to a hybrid Quadrupole Time of Flight Mass Spectrometry (HPLC-PDA-QTOF/MS). MALDI-TOF/MS failed to detect non-polar MCs, such as MC-LY and MC-LW. HPLC-QTOF/MS permitted the accurate identification of most MCs present in methanolic extracts. Besides, three new MCs, namely: [D-Glu(OCH3)6, D-Asp3] MC-LAba, MC-YL and MC-YM were detected by HPLC-QTOF/MS. 相似文献
549.
Hua-Yun Xiao Cong-Guo Tang Hong-Wei Xiao Yan-Li Wang Xue-Yan Liu Cong-Qiang Liu 《Environmental pollution (Barking, Essex : 1987)》2010,158(5):1726-1732
In urban cities in Southern China, the tissue S/N ratios of epilithic mosses (Haplocladium microphyllum), varied widely from 0.11 to 0.19, are strongly related to some atmospheric chemical parameters (e.g. rainwater SO42−/NH4+ ratios, each people SO2 emission). If tissue S/N ratios in the healthy moss species tend to maintain a constant ratio of 0.15 in unpolluted area, our study cities can be divided into two classes: class I (S/N > 0.15, S excess) and class II (S/N < 0.15, N excess), possibly indicative of stronger industrial activity and higher density of population, respectively. Mosses in all these cities obtained S and N from rainwater at a similar ratio. Sulphur and N isotope ratios in mosses are found significantly linearly correlated with local coal δ34S and NH4+-N wet deposition, respectively, indicating that local coal and animal NH3 are the major atmospheric S and N sources. 相似文献
550.
采用浸渍法制备了CuO/BiVO4光催化剂,通过X射线衍射(XRD)、热重/差示扫描量热(TG/DSC)和傅立叶红外光谱(FTIR)对其进行了表征,并在可见光照射下考察了其光催化氧化亚甲基蓝(MB)的动力学特性。结果表明,Cu的掺杂并未改变BiVO4的晶型结构;Cu(NO3)2/BiVO4在热处理(30~300℃)过程中,NO3-已经完全分解,Cu最终以CuO的形式存在于CuO/BiVO4光催化剂体系中;掺杂不同量Cu的CuO/BiVO4中的Cu2+/Bi+(摩尔比)实测值与理论值相近,该系列光催化剂的合成过程具有较高的可信度;在可见光照射下,CuO/BiVO4光催化降解MB反应符合表观一级反应动力学特征;当Cu2+/Bi+为0.050时,反应动力学速率常数(k)达到最高值(0.4334h-1),此时的k比单体BiVO4作用下的提高了1.04倍;由于异质结的存在,CuO/BiVO4与单体BiVO4相比,电子和空穴的利用率大大增加,使得CuO/BiVO4的光催化活性较单体BiVO4有了大幅度提高。 相似文献