全文获取类型
收费全文 | 2792篇 |
免费 | 197篇 |
国内免费 | 808篇 |
专业分类
安全科学 | 224篇 |
废物处理 | 133篇 |
环保管理 | 299篇 |
综合类 | 1318篇 |
基础理论 | 400篇 |
污染及防治 | 1031篇 |
评价与监测 | 158篇 |
社会与环境 | 130篇 |
灾害及防治 | 104篇 |
出版年
2024年 | 7篇 |
2023年 | 59篇 |
2022年 | 145篇 |
2021年 | 128篇 |
2020年 | 99篇 |
2019年 | 76篇 |
2018年 | 81篇 |
2017年 | 142篇 |
2016年 | 124篇 |
2015年 | 136篇 |
2014年 | 191篇 |
2013年 | 294篇 |
2012年 | 218篇 |
2011年 | 236篇 |
2010年 | 175篇 |
2009年 | 165篇 |
2008年 | 205篇 |
2007年 | 187篇 |
2006年 | 158篇 |
2005年 | 118篇 |
2004年 | 93篇 |
2003年 | 116篇 |
2002年 | 105篇 |
2001年 | 115篇 |
2000年 | 76篇 |
1999年 | 65篇 |
1998年 | 36篇 |
1997年 | 47篇 |
1996年 | 39篇 |
1995年 | 29篇 |
1994年 | 19篇 |
1993年 | 11篇 |
1992年 | 21篇 |
1991年 | 20篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 8篇 |
1987年 | 2篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 5篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1973年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有3797条查询结果,搜索用时 31 毫秒
941.
微波-Fenton对沼液中抗生素和激素的高级氧化 总被引:2,自引:1,他引:1
采用微波强化Fenton氧化处理系统,研究H2O2浓度、Fe2+浓度、初始pH、微波辐射时间和微波辐射功率对沼液中喹乙醇、土霉素、四环素及金霉素降解效果的影响.结果发现,采用微波强化Fenton氧化降解沼液中抗生素与激素的最优条件是:H2O2浓度为40 mg/L、Fe2+浓度为12 mg/L、初始pH为4、微波辐射时间为2 min、微波辐射功率为中火(445W),沼液中喹乙醇、土霉素、四环素、金霉素和COD的去除率分别达到67%、93%、91%、88%和46%.在水浴条件下,与单独微波辐射和单独Fenton相比,微波强化Fenton氧化有明显的优越性. 相似文献
942.
Based on the consumer questionnaires of the three traditional retailing centers,Qianmen,Wangfujing and Xidan in Beijing,this article analyzes the present features of consumer composition in the three retailing centers.What is more,the evolution course and function transition of traditional retailing centers is revealed based on the changing of consumer composition in different times.Lastly,the renewal method and development trends of traditional retailing centers are discussed based on the evaluation results in consumers' perspective. 相似文献
943.
近些年以来,我国的经济增长速度非常快,经济发展取得了一定的成绩。不过严重的环境污染问题也随之而来。积极开展环境质量的监测工作,有利于带给相关环境监测技术人员更多的借鉴和帮助,增强环境监测与污染治理的效果。所以,不断提高环境监测数据的质量可谓十分关键。本文通过阐释了环境监测的概念及内涵,说明了常见的环境监测数据分析方法,同时制定出提高环境监测数据质量的合理对策,从而有效提升了环境监测数据信息的整体质量。 相似文献
944.
Long Zhou Thomas Woodfin Tian Chen Kun Song 《Journal of Environmental Planning and Management》2018,61(3):430-450
A city's spatial footprint is covered by extensive impervious building roofs and paved surfaces, which contribute to greater storm-water runoff, more surface pollutants, and less carbon sequestration, hence, worse ecosystem services. This research conducts an empirical study on the ecological and economic impacts of a citywide adoption of green roofs and permeable pavements in Corvallis, OR. The effects on ecosystem services of using green roofs and pervious pavements for a low impact development are modelled using Integrated Value of Ecosystem Services Trade-offs and compared to those from the City's current conventional development without green roofs and pervious pavements. The differences are analysed for ecological impact by storm-water yield, storm-water purification, and carbon sequestration and economic impact by a cost-benefit comparison. The results indicate that low impact development, especially intensive green roofs on commercial/industrial buildings and permeable pavements for parking lots, plays a significant role, even with a higher initial implementation cost, for long-term urban sustainability. 相似文献
945.
In this work, a two-step method for the extraction of pectin and cellulose fiber from mulberry branch bark, a by-product of
sericultural industry, was described. The method was based on the acid extraction of pectin and subsequently alkali treatment
for obtaining cellulose fibers. The obtained pectin was high purity with the total galacturonic acid content of 85.46% ± 2.76%
and the degree of esterification of 71.13% ± 1.67%. The chemical composition analysis, FTIR spectroscopy, XRD and TG analysis
were used to characterize the cellulose fiber at different processing stages. After the two-step chemical process, the cellulose
content was increased from 37.38% in original bark to 92.60% in cellulose fiber. The FTIR spectra revealed the removal of
pectin, hemicelluloses and lignin from the bark by acid extraction and alkali treatment. The XRD and TG results indicated
that the obtained cellulose fibers were with the increased crystallinity and thermal stability, whose crystallinity and degradation
temperature were 86.36% ± 5.56% and 355 °C, respectively. This work may provide a new approach for high utilization of mulberry
branch bark. 相似文献
946.
947.
Bon-Jun Koo Andrew C. Chang Thomas C. Granato 《Environmental pollution (Barking, Essex : 1987)》2010,158(8):2582-574
Organic acids present in the rhizosphere of growing plants are widely recognized to be responsible for dissolving the solid phase metals in the soil and making them available for plant absorption. We proposed a root exudates-based model to assess the long-term phytoavailability of metals in biosolids-amended soils. The phytoavailability of biosolids-borne metals was defined in terms of a capacity factor and an intensity factor. The plant available metal pool, C0 (capacity factor, mg kg−1), can be estimated by fitting the successive organic acids extraction data to an exponential decay kinetic equation. The field metal removal rate, k (intensity factor, yr−1), can be estimated from the successive extraction-based metal release rate through an effective annual organic acid production in the rhizosphere which was found to be characteristic of plant species. The protocol was successfully used to assess the long-term phytoavailability of metals in biosolids-amended soil from two biosolids land application sites. 相似文献
948.
This research utilized the Ames test to determine the mutagenicity of water treated by advanced processes, including ozonation and granular activated carbon (GAC). Raw water samples for this research included those obtained from the Pan Hsin waterworks as well as samples containing humic acids. Treated samples were collected from the pilot‐scale advanced treatment plant. The Ames test was used to measure the mutagenicity of the water after each treatment process. For the Pan Hsin raw water samples treated with ozone or GAC, it was indicated that, regardless of whether samples were preozonated or not, they all showed a mutagenic potency less than 2 once the S9 enzyme was added. This level of mutagenicity is insignificant. The prepared humic acid samples, on the other hand, demonstrated a significant reduction in mutagenicity after the pre‐ozonation process, indicating that preozonation can lower the degree of mutagenicity. Furthermore, the mutagenicity of the prepared humic acid samples gradually decreased after the advanced treatment process. However, when chlorine was added later to these samples, the mutagenicity increased again. This research shows that the use of O3/GAC processes to treat water can successfully lower mutagenicity, indicating a great potential for applications in the treatment of drinking water. 相似文献
949.
Hao Chen Xiaosong Chang Ji-an Chen Yebin Guo Yao Tan 《Environmental pollution (Barking, Essex : 1987)》2010,158(7):2459-2464
The spreading of extended-spectrum β-lactamases (ESBL)-producing thermotolerant coliforms (TC) in the water environment is a threat to human health but little is known about ESBL-producing TCs in the Yangtze River. We received 319 ESBL-producing stains obtained from the Chongqing basin and we investigated antibiotic susceptibility, bla gene types and the presence of integrons and gene cassettes. 16.8% of TC isolates were ESBL-producing bacteria and blaTEM+CTx-M was the predominant ESBL type. 65.2% of isolates contained class 1 integrons, but only 3 carried intI 2. Gene cassettes were amplified and sequenced. aadA, drfA, cmlA, sat1, aar3 and two ORF cassettes were found. In conclusion, Yangtze River is heavily polluted by ESBL-producing TC bacteria and the combined bla gene type could enhance antibiotic resistance. Class 1 integrons were widespread in ESBL-producing isolates and play an important role in multi-drug resistance. Characterization of gene cassettes could reveal the dissemination of antibiotic resistance genes. 相似文献
950.
In this study, we examined the experimental catalytic oxidation of gaseous monochlorobenzene (MCBz) with O3 over Fe2O3 in a packed bed reactor to investigate the feasibility of economical low temperature decomposition at a high space velocity (SV). We investigated the effects of several reaction parameters (temperature, O3 concentration, and SV) on the MCBz oxidation. At 150 °C, the conversion of MCBz over Fe2O3 in the absence of O3 was only 3%; it increased to 91% over Fe2O3 in the presence of 1200 ppm of O3 at a high SV of 83 s−1. A long-term operation study revealed that the conversion of MCBz was stable for more than 96 h. In the steady state, the carbon and chlorine balances were 88% and 86%, respectively. Applying a Langmuir-Hinshelwood kinetic model, we estimated an activation energy of 16.7 kJ mol−1 for MCBz oxidation over Fe2O3 in the presence of O3. 相似文献