全文获取类型
收费全文 | 2285篇 |
免费 | 128篇 |
国内免费 | 701篇 |
专业分类
安全科学 | 179篇 |
废物处理 | 141篇 |
环保管理 | 166篇 |
综合类 | 1273篇 |
基础理论 | 375篇 |
污染及防治 | 683篇 |
评价与监测 | 132篇 |
社会与环境 | 83篇 |
灾害及防治 | 82篇 |
出版年
2024年 | 8篇 |
2023年 | 56篇 |
2022年 | 153篇 |
2021年 | 123篇 |
2020年 | 93篇 |
2019年 | 97篇 |
2018年 | 104篇 |
2017年 | 112篇 |
2016年 | 133篇 |
2015年 | 123篇 |
2014年 | 141篇 |
2013年 | 238篇 |
2012年 | 196篇 |
2011年 | 199篇 |
2010年 | 134篇 |
2009年 | 134篇 |
2008年 | 130篇 |
2007年 | 137篇 |
2006年 | 103篇 |
2005年 | 82篇 |
2004年 | 51篇 |
2003年 | 73篇 |
2002年 | 74篇 |
2001年 | 46篇 |
2000年 | 56篇 |
1999年 | 55篇 |
1998年 | 46篇 |
1997年 | 37篇 |
1996年 | 42篇 |
1995年 | 28篇 |
1994年 | 15篇 |
1993年 | 27篇 |
1992年 | 15篇 |
1991年 | 9篇 |
1990年 | 11篇 |
1989年 | 3篇 |
1988年 | 11篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1976年 | 1篇 |
1958年 | 1篇 |
1956年 | 2篇 |
1930年 | 1篇 |
排序方式: 共有3114条查询结果,搜索用时 15 毫秒
111.
Pretreatment of thickened waste activated sludge (TWAS) by combined microwave and alkaline pretreatment (MAP) was studied to
improve thermophilic anaerobic digestion efficiency. Uniform design was applied to determine the combination of target temperature
(110–210°C), microwave holding time (1–51 min), and NaOH dose (0–2.5 g NaOH/g suspended solids (SS)) in terms of their effect
on volatile suspended solids (VSS) solubilization. Maximum solubilization ratio (85.1%) of VSS was observed at 210°C with 0.2
g-NaOH/g-SS and 35 min holding time. The effects of 12 different pretreatment methods were investigated in 28 thermophilic batch
reactors by monitoring cumulative methane production (CMP). Improvements in methane production in the TWAS were directly related
to the microwave and alkaline pretreatment of the sludge. The highest CMP was a 27% improvement over the control. In spite of the
increase in soluble chemical oxygen demand concentration and the decrease in dewaterability of digested sludge, a semi-continuous
thermophilic reactor fed with pretreated TWAS without neutralization (at 170°C with 1 min holding time and 0.05 g NaOH/g SS)
was stable and functioned well, with volatile solid (VS) and total chemical oxygen demand (TCOD) reductions of 28% and 18%,
respectively, which were higher than those of the control system. Additionally, methane yields (L@STP/g-CODadded, at standard
temperature and pressure (STP) conditions of 0°C and 101.325 kPa) and (L@STP/g VSadded) increased by 17% and 13%, respectively,
compared to the control reactor. 相似文献
112.
Aged refuse from waste landfills closed for eight years was examined and found to contain rich methanotrophs capable of biooxidation
for methane. Specially, community structure and methane oxidation capability of methanotrophs in the aged refuse were
studied. The amount of methanotrophs ranged 61.97 103–632.91 103 cells/g (in dry basis) in aged refuse from Shanghai Laogang
Landfill. Type I and II methanotrophs were found in the aged refuse in the presence of sterilized sewage sludge and only Type I
methanotrophs were detected in the presence of nitrate minimal salt medium (NMS). The clone sequences of the pmoA gene obtained
from the aged refuse were similar to the pmoA gene of Methylobacter, Methylocaldum, and Methylocystis, and two clones were distinct
with known genera of Type I methanotrophs according to phylogenetic analysis. Aged refuse enriched with NMS was used for methane
biological oxidation and over 93% conversions were obtained. 相似文献
113.
Xinxin Wang Zhen Han Zhihui Bai Jingchun Tang Anzhou M Jizheng He Guoqiang Zhuang 《环境科学学报(英文版)》2011,23(11):1858-1864
The impact of petroleum on archaeal community in salinealkali soils was investigated, which will expand the knowledge of the archaeal population involved in the natural attenuation of hydrocarbons in extreme environments. 相似文献
114.
115.
116.
Catalytic oxidation is widely used in pollution control technology to remove volatile organic compounds. In this study, Pd/ZSM-5 catalysts with different Pd contents and acidic sites were prepared via the impregnation method. All the catalysts were characterized by means of N2 adsorption- desorption, X-ray fluorescence (XRF), HE temperature programmed reduction (H2-TPR), and NH3 temperature programmed desorption (NH3-TPD). Their catalytic performance was investigated in the oxidation of butyl acetate experiments. The by-products of the reaction were collected in thermal desorption tubes and identified by gas chromatography/mass spectrometry. It was found that the increase of Pd content slightly changed the catalytic activity of butyl acetate oxidation according to the yield of CO2 achieved at 90%, but decreased the cracking by-products, whereas the enhancement of strong acidity over Pd-based catalysts enriched the by-product species. The butyl acetate oxidation process involves a series of reaction steps including protolysis, dehydrogenation, dehydration, cracking, and isomerization. Generally, butyl acetate was cracked to acetic acid and 2- methylpropene and the latter was an intermediate of the other by-products, and the oxidation routes of typical by-products were proposed. Trace amounts of 3-methylpentane, hexane, 2-methylpentane, pentane, and 2-methylbutane originated from iso4merization and protolysis reactions. 相似文献
117.
The photocatalytic degradation of methylene blue(MB) over Fe-doped CaTiO3 under UV-visible light was investigated. The as-prepared samples were characterized using X-ray diffraction(XRD), scanning electron microscope(SEM) equipped with an energy dispersive spectrometer(EDS) system, Fourier transform infrared spectra(FT-IR), and UV-visible diffuse reflectance spectroscopy(DRS). The results show that the doping with Fe significantly promoted the light absorption ability of CaTiO3 in the visible light region. The Fe-doped CaTiO3 exhibited higher photocatalytic activity than CaTiO3 for the degradation of MB.However, the photocatalytic activity of the Fe-doped CaTiO3 was greatly influenced by the calcination temperature during the preparation process. The Fe-doped CaTiO3 prepared at500°C exhibited the best photocatalytic activity, with degradation of almost 100% MB(10 ppm)under UV-visible light for 180 min. 相似文献
118.
Higher concentrations of Hg can be emitted from coal pyrolysis or gasification than from coal combustion, especially elemental Hg. Highly efficient Hg removal technology from coal-derived fuel gas is thus of great importance. Based on the very excellent Hg removal ability of Pd and the high adsorption abilities of activated carbon(AC) for H2 S and Hg, a series of Pd/AC sorbents was prepared by using pore volume impregnation, and their performance in capturing Hg and H2 S from coal-derived fuel gas was investigated using a laboratory-scale fixed-bed reactor. The effects of loading amount, reaction temperature and reaction atmosphere on Hg removal from coal-derived fuel gas were studied. The sorbents were characterized by N2 adsorption, X-ray diffraction(XRD) and X-ray photoelectron spectroscopy(XPS). The results indicated that the efficiency of Hg removal increased with the increasing of Pd loading amount, but the effective utilization rate of the active component Pd decreased significantly at the same time. High temperature had a negative influence on the Hg removal. The efficiency of Hg removal in the N2-H2S-H2-CO-Hg atmosphere(simulated coal gas) was higher than that in N2-H2S-Hg and N2-Hg atmospheres, which showed that H2 and CO, with their reducing capacity, could benefit promote the removal of Hg. The XPS results suggested that there were two different ways of capturing Hg over sorbents in N2-H2S-Hg and N2-Hg atmospheres. 相似文献
119.
闫函 《中国ISO14000认证》2014,(3):9-13
概括了循环经济工业园区规划环境影响评价的框架思路。归纳总结了规划环评的主要内容,并以山西省长治市襄垣富阳循环经济工业园区为例,对规划环评指标体系的构建进行探讨。 相似文献
120.
增强多氯联苯(PCBs)的水溶性是强化PCBs微生物降解的主要控制因素之一,本研究选取了PCB5(2,3-CB)和PCB31(2,4',5-CB)作为低氯代PCBs的典型代表,以曲拉通100(TX-100)、吐温80(Tween 80)、鼠李糖脂粗提物(RL crude)3种表面活性剂和β-环糊精( HPCD)联合Burkholderia xenoνorans LB400构建PCBs好氧降解体系,测试了它们对PCB5和PCB31的溶出率及微生物生长的影响.结果表明,TX-100(CMC=194 mg·L-1)、 Tween 80(CMC=13.1 mg·L-1)、 RL crude(CMC=50 mg·L-1)浓度在1~7 CMC 时和 HPCD 浓度在500~1500 mg·L-1时对 PCB5和 PCB31溶出率分别达到54.7%~100%、59.8%~100%;10.5%~40.8%、6.8%~31.6%;10.3%~19.9%、3.3%~11.6%和19.5%~34.2%、4.2%~10.7%. TX-100浓度在1~7 CMC时对B. xenoνorans LB400生长的抑制率达到30.3%~45.8%,而Tween 80浓度在0.1~1 CMC时对其生长的抑制率为10.0%~15.4%; RL crude 本身能作为底物促进 LB400的生长,而 HPCD 对其生长无明显影响. B. xenoνorans LB400对PCB31(5 mg·L-1)的降解效率在添加表面活性剂后有不同程度的提高:TX-100,23.7%~65.5%; Tween 80,14.6%~44.3%;RL crude,9.6%~27.2%;HPCD,15.3%~20.7%;而表面活性剂对PCB5(10 mg·L-1)的降解效率则无明显影响.表面活性剂主要通过增大溶液中PCBs-表面活性剂的胶束浓度来提高LB400对PCBs的降解效率,在水溶液培养体系中当设置TX-100和Tween 80浓度分别在1和7 CMC时,PCB31的降解效率达到100%和81.7%,而此时B. xenoνorans LB400生长的抑制率为30.3%和5.4%. 相似文献