全文获取类型
收费全文 | 814篇 |
免费 | 24篇 |
国内免费 | 70篇 |
专业分类
安全科学 | 45篇 |
废物处理 | 38篇 |
环保管理 | 76篇 |
综合类 | 235篇 |
基础理论 | 174篇 |
环境理论 | 4篇 |
污染及防治 | 235篇 |
评价与监测 | 41篇 |
社会与环境 | 50篇 |
灾害及防治 | 10篇 |
出版年
2024年 | 3篇 |
2023年 | 13篇 |
2022年 | 20篇 |
2021年 | 20篇 |
2020年 | 19篇 |
2019年 | 13篇 |
2018年 | 35篇 |
2017年 | 28篇 |
2016年 | 28篇 |
2015年 | 26篇 |
2014年 | 30篇 |
2013年 | 49篇 |
2012年 | 34篇 |
2011年 | 57篇 |
2010年 | 41篇 |
2009年 | 43篇 |
2008年 | 40篇 |
2007年 | 52篇 |
2006年 | 39篇 |
2005年 | 26篇 |
2004年 | 38篇 |
2003年 | 27篇 |
2002年 | 31篇 |
2001年 | 12篇 |
2000年 | 11篇 |
1999年 | 8篇 |
1998年 | 16篇 |
1997年 | 18篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 15篇 |
1993年 | 7篇 |
1992年 | 7篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1980年 | 3篇 |
1976年 | 3篇 |
1966年 | 3篇 |
1964年 | 3篇 |
1963年 | 3篇 |
1962年 | 2篇 |
1961年 | 3篇 |
1960年 | 3篇 |
1959年 | 2篇 |
1957年 | 5篇 |
1956年 | 6篇 |
1955年 | 4篇 |
1954年 | 2篇 |
1951年 | 3篇 |
1922年 | 3篇 |
排序方式: 共有908条查询结果,搜索用时 687 毫秒
731.
Stasinakis AS Thomaidis NS Nikolaou A Kantifes A 《Environmental pollution (Barking, Essex : 1987)》2005,134(3):431-438
The biodegradation behavior of four organotin (OT) compounds, namely tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT) and triphenyltin (TPhT), was studied in lab-scale activated sludge batch reactors. The activated sludge was spiked with the OT compounds at a level of 100 microg l(-1) as Sn. Determination of the OT compounds by GC-FPD after ethylation in the dissolved and particulate phase revealed that 24 h after the start of the experiments, almost the total of OT compounds has been removed from the dissolved phase and is associated with the suspended solids. Calculation of mass balance in batch reactors showed that OT compounds biodegradation was performed via a sequential dealkylation process. Removals due to biodegradation were differentiated according to the parent compound. In experiments with non-acclimatized biomass, a percentage of 27.1, 8.3, 73.8 and 51.3 was still present as TBT, DBT, MBT and TPhT, respectively, at the end of the experiment (18th day). Half-lives (t1/2) of 10.2 and 5.1 days were calculated for TBT and DBT, respectively, whereas apparent t1/2 values could not be determined for MBT and TPhT (t1/2>18 days). The capacity of activated sludge to biodegrade OT compounds in the absence of supplemental substrate indicated that these compounds can be metabolized as single sources of carbon and energy in activated sludge systems. Excluding TBT, the presence of low concentrations of supplemental substrate did not affect the biodegradation potential of activated sludge. The acclimatization of biomass on OT compounds enhanced significantly biodegradation, resulting in significant decreases of half-lives of OT compounds. As a result in the presence of acclimatized biomass, half-lives of 1.4, 3.6, 9.8 and 5.0 days were calculated for TBT, DBT, MBT and TPhT, respectively. 相似文献
732.
Patrick Riefer Timm Klausmeyer Burkhard Schmidt Andreas Schäffer 《Journal of environmental science and health. Part. B》2017,52(8):584-599
The incorporation of xenobiotics into soil, especially via covalent bonds or sequestration has a major influence on the environmental behavior including toxicity, mobility, and bioavailability. The incorporation mode of 4-chloro-2-methylphenoxyacetic acid (MCPA) into organo-clay complexes has been investigated under a low (8.5 mg MCPA/kg soil) and high (1000 mg MCPA/kg soil) applied concentration, during an incubation period of up to 120 days. Emphasis was laid on the elucidation of distinct covalent linkages between non-extractable MCPA residues and humic sub-fractions (humic acids, fulvic acids, and humin). The cleavage of compounds by a sequential chemical degradation procedure (OH?, BBr3, RuO4, TMAH thermochemolysis) revealed for both concentration levels ester/amide bonds as the predominate incorporation modes followed by ether linkages. A possible influence of the soil microbial activity on the mode of incorporation could be observed in case of the high level samples. Structure elucidation identified MCPA as the only nonextractable substance, whereas the metabolite 4-chloro-2-methylphenol was additionally found as bioavailable and bioaccessible compound. 相似文献
733.
734.
Guangli Xiu Ji Cai Wenying Zhang Danian Zhang Andreas Büeler Shuncheng Lee Yan Shen Lihang Xu Xuejuan Huang Ping Zhang 《Atmospheric environment (Oxford, England : 1994)》2009,43(19):3145-3154
Size-fractionated particles were collected at two sites from July 2004 to April 2006 in Shanghai. The mercury in particles was extracted and divided operationally into four species: exchangeable particulate mercury (EXPM), HCl-soluble particulate mercury (HPM), elemental particulate mercury (EPM) and residual particulate mercury. The total particulate Hg concentration during the study period ranged from 0.07 ng m?3 to 1.45 ng m?3 with the average 0.56 ± 0.22 ng m?3 at site 1, while 0.20 ng m?3–0.47 ng m?3 with the average 0.33 ± 0.09 ng m?3 at site 2, which is far higher than some foreign cities and comparable to some cities with heavy air pollution in China. The Hg mass content also displayed evident size distribution, with higher value in PM1.6–3.7, somewhat higher or lower than the source profile. EXAM was only found in the summer, HPM have higher percentage in summer and fall rather than in winter and spring. The different mercury species showed different correlation to temperature, relative humidity, wind speed. HPM positively depends on temperature at both sites which implies the importance of mercury transformation on particles. In foggy days TPM increased greatly, but HPM didn't vary greatly as anticipated. Instead, RPM gained a distinguished increase. It demonstrated that aqueous reaction and complex heterogenic reactions in droplet might happen in acidic environment. The correlation of mercury with other pollutants including SO2, NO2, CO and PM10 varies with the different mercury forms. Hybrid single-particle lagrangian integrated trajectories (HYSPLIT) model was used to back trace air mass at different representative days and results indicated that transportation from Huabei Plain will increase mercury concentration in winter and fall to some extent. The possible existing compounds and their atmospheric behavior of HPM, EPM and RPM were calculated and the compared to analyze its implication on atmospheric mercury cycle. 相似文献
735.
Mats Gustafsson Göran Blomqvist Anders Gudmundsson Andreas Dahl Per Jonsson Erik Swietlicki 《Atmospheric environment (Oxford, England : 1994)》2009,43(31):4699-4702
Accelerated pavement wear is one of the major environmental disadvantages of studded tyres in northern regions and results in increased levels of PM10. Measurements of PM10 in a road simulator hall have been used to study the influence of pavement properties, tyre type and vehicle speed on pavement wear. The test set-up included three different pavements (one granite and two quartzite with different aggregate sizes), three different tyre types (studded, non-studded, and summer tyres) and different speeds (30–70 km h?1). The results show that the granite pavement was more prone to PM10 production compared to the quartzite pavements. Studded winter tyres yield tens of times higher PM10 concentrations compared to non-studded winter tyres. Wear from summer tyres was negligible in comparison. It was also shown that wear is strongly dependent on speed; every 10 km h?1 increase yielded an increase of the PM10 concentration of 680 μg m?3 in one of the simulator experiments. 相似文献
736.
改进型升流式固体反应器处理猪粪污新工艺研究 总被引:6,自引:1,他引:5
对传统升流式固体反应器(USR)进行改进,反应器内设置专用搅拌器,搅拌器间歇开启,在保留USR各项优势的前提下,使料液与厌氧微生物接触更充分,反应温度更均匀,提高产气率,同时还解决了传统USR的“结壳”问题,提高了反应器的传质效率、甲烷产气率和COD去除效果。进料含固量在12.1%时,水利停留时间为17 d,反应器最高容积负荷达到4.9 kg COD/(m3·d),产气速率为2.55 m3/(m3·d),产气率达到0.359 m3/kg干猪粪。 相似文献
737.
Nicolai D. Jablonowski Stephan Köppchen Andreas Schäffer 《Environmental pollution (Barking, Essex : 1987)》2009,157(7):2126-2131
Twenty-two years after the last application of ring-14C-labeled atrazine at customary rate (1.7 kg ha−1) on an agriculturally used outdoor lysimeter, atrazine is still detectable by means of accelerated solvent extraction and LC-MS/MS analysis. Extractions of the 0-10 cm soil layer yielded 60% of the residual 14C-activity. The extracts contained atrazine (1.0 μg kg−1) and 2-hydroxy-atrazine (42.5 μg kg−1). Extractions of the material of the lowest layer 55-60 cm consisting of fine gravel yielded 93% of residual 14C-activity, of which 3.4 μg kg−1 was detected as atrazine and 17.7 μg kg−1 was 2-hydroxy-atrazine. The detection of atrazine in the lowest layer was of almost four times higher mass than in the upper soil layer. These findings highlight the fact that atrazine is unexpectedly persistent in soil. The overall persistence of atrazine in the environment might represent a potential risk for successive groundwater contamination by leaching even after 22 years of environmental exposure. 相似文献
738.
Gerhard Lammel Jana Klánová Roman Prokeš Andreas Stohl 《Environmental pollution (Barking, Essex : 1987)》2009,157(12):3264-3271
On Zugspitze (2670 m a.s.l.), Alps, higher concentrations were observed during a winter than during a summer measurement campaign of PAHs, chlorobenzenes (43.6 vs. 2.0 pg m−3) and DDTs (3.7 vs. 1.2 pg m−3), while hexachlorocyclohexanes and PCBs were found at similar levels. The PCB, HCH and DDT levels are among the lowest ever reported from outside the Arctic. Mostly lower levels were found in samples collected in summer than in winter despite a significant boundary layer air influence, but no such influence on samples collected during the winter campaign. Boundary layer influence was quantified by Lagrangian particle dispersion model retroplume analyses. Photochemical lifetimes corresponding to kOH < 1.5 × 10−12 cm3 molec−1 s−1 are found for p,p′-DDT, kOH < 0.75 × 10−12 cm3 molec−1 s−1 for p,p′-DDE and kOH < 1.0 × 10−12 cm3 molec−1 s−1 for p,p′-DDD. 相似文献
739.
Chunyan Liu Jirko Holst Zhisheng Yao Nicolas Brüggemann Klaus Butterbach-Bahl Shenghui Han Xingguo Han Bart Tas Andreas Susenbeth Xunhua Zheng 《Atmospheric environment (Oxford, England : 1994)》2009,43(19):3086-3095
We present a methane (CH4) budget for the area of the Baiyinxile Livestock Farm, which comprises approximately 1/3 of the Xilin river catchment in central Inner Mongolia, P.R. China. The budget calculations comprise the contributions of natural sources and sinks as well as sources related to the main land-use in this region (non-nomadic pastoralism) during the growing season (May–September). We identified as important CH4 sources floodplains (mean 1.55 ± 0.97 mg CH4–C m?2 h?1) and domestic ruminants, which are mainly sheep in this area. Within the floodplain significant differences between investigated positions were detected, whereby only positions close-by the river or bayous emitted large amounts of CH4 (mean up to 6.21 ± 1.83 mg CH4–C m?2 h?1). Further CH4 sources were sheepfolds (0.08–0.91 mg CH4–C m?2 h?1) and pasture faeces (1.34 ± 0.22 mg CH4–C g?1 faeces dry weight), but they did not play a significant role for the CH4 budget. In contrast, dung heaps were not a net source of CH4 (0.0 ± 0.2 for an old and 0.0 ± 0.3 μg CH4–C kg?1 h?1 for a new dung heap). Trace gas measurements along two landscape transects (volcano, hill slope) revealed expectedly a mean CH4 uptake (volcano: 76.5 ± 4.3; hill: 28.3 ± 5.3 μg CH4–C m?2 h?1), which is typical for the aerobic soils in this and other steppe ecosystems. The observed fluxes were rarely influenced by topography.The CH4 emissions from the floodplain and the sheep were not compensated by the CH4 oxidation of aerobic steppe soils and thus, this managed semi-arid grassland did not serve as a terrestrial sink, but as a source for this globally important greenhouse gas. The source strength amounted to 1.5–3.6 kg CH4–C ha?1 during the growing season, corresponding to 3.5–8.7 kg C ha?1 yr?1. 相似文献
740.
Eleni?NanouEmail author Chrissanthi?Hountala Argiro?Maganioti Charalabos?Papageorgiou Vassilis?Tsiafakis Andreas?Rabavilas Christos?Capsalis 《The Environmentalist》2009,29(2):205-209
The present study investigated the influence of electromagnetic fields (EMF), similar to that emitted by mobile phones, on
brain activity. Ten women and ten men, matched for age and educational level, performed a short memory task (Wechsler test),
with simultaneous Electroencephalogram (EEG) recordings at 15 scalp electrodes, both without (baseline) and with exposure
to an 1,800 MHz signal. The EEG energy was found concentrated at the four basic EEG bands [α (8–13 Hz), β (14–30 Hz), δ (0–4 Hz), and θ (5–7 Hz)]. The analysis revealed that in the presence of EMF, the energy of the β band was significantly greater for females than for males at the majority of the electrodes. Since beta oscillation is associated
with the shift of attention during the perception, these findings may indicate that the particular EMF (1,800 MHz signal)
exerts an influence on this brain activity, which appears to be gender-related. 相似文献