全文获取类型
收费全文 | 1719篇 |
免费 | 20篇 |
国内免费 | 47篇 |
专业分类
安全科学 | 22篇 |
废物处理 | 126篇 |
环保管理 | 164篇 |
综合类 | 153篇 |
基础理论 | 317篇 |
环境理论 | 2篇 |
污染及防治 | 583篇 |
评价与监测 | 307篇 |
社会与环境 | 108篇 |
灾害及防治 | 4篇 |
出版年
2023年 | 62篇 |
2022年 | 179篇 |
2021年 | 122篇 |
2020年 | 26篇 |
2019年 | 49篇 |
2018年 | 89篇 |
2017年 | 93篇 |
2016年 | 113篇 |
2015年 | 48篇 |
2014年 | 82篇 |
2013年 | 189篇 |
2012年 | 76篇 |
2011年 | 96篇 |
2010年 | 69篇 |
2009年 | 72篇 |
2008年 | 79篇 |
2007年 | 63篇 |
2006年 | 64篇 |
2005年 | 39篇 |
2004年 | 25篇 |
2003年 | 20篇 |
2002年 | 32篇 |
2001年 | 8篇 |
2000年 | 9篇 |
1999年 | 5篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1979年 | 2篇 |
1969年 | 1篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1964年 | 2篇 |
1962年 | 2篇 |
1961年 | 4篇 |
1958年 | 3篇 |
1957年 | 3篇 |
1956年 | 2篇 |
1955年 | 4篇 |
1953年 | 1篇 |
排序方式: 共有1786条查询结果,搜索用时 281 毫秒
821.
Xinquan Zhang A. Senthil Kumar Mustafizur Rahman Chandra Nath Kui Liu 《Journal of Manufacturing Processes》2012,14(3):378-387
The elliptical vibration cutting (EVC) technique has been found to be a promising technique for ultraprecision machining of various materials. In each overlapping EVC cycle, the thickness of cut (TOC) of work material, and the tool velocity get continuously varied. These two inherent phenomena, in fact, introduce transient characteristics into its cutting mechanics, which are considered to be different from the one applied for conventional cutting technique. Recently, a few theoretical models have been developed to understand the material removal mechanism with the EVC technique; however, in those studies, the transient phenomena were not considered. In the present research, an analytical force model for the orthogonal EVC process was developed in order to fully understand the EVC mechanism, and to more accurately predict the transient cutting force values. Three important factors: (i) transient TOC, (ii) transient shear angle, and (iii) transition characteristic of friction reversal were investigated and analyzed mainly based on geometric modeling and the Lee and Shaffer's slip-line solution. Mathematical evaluation shows that they may have significant influence on EVC process, and thus on its output performance. In order to validate the proposed force model, a series of low-frequency orthogonal EVC tests were conducted. The experimental transient cutting force values were compared with the predicted values calculated using the proposed model, and they are found to be in a good agreement with each other. 相似文献
822.
Sarkar Santosh Kumar Mondal Priyanka Biswas Jayanta Kumar Kwon Eilhann E. Ok Yong Sik Rinklebe Jörg 《Environmental geochemistry and health》2018,40(1):567-567
Environmental Geochemistry and Health - Unfortunately, in the original publication of the article, Prof. Yong Sik Ok’s affiliation was incorrectly published. The author’s affiliation is... 相似文献
823.
Goel Abhishek Kumar Singh Shailendra Narayan 《Environmental science and pollution research international》2021,28(16):19958-19958
Environmental Science and Pollution Research - A Correction to this paper has been published: https://doi.org/10.1007/s11356-021-12458-z 相似文献
824.
Shrivas Vijay Laxmi Choudhary Anil Kumar Hariprasad Puttaswamy Sharma Shilpi 《Environmental science and pollution research international》2023,30(10):25141-25147
Environmental Science and Pollution Research - Antimicrobial resistance (AMR) in cattle is widespread because of the increased use of antibiotics to combat microbial diseases and enhance milk... 相似文献
825.
Subas Chandra Asa Prasanta Rath Unmesh Chandra Panda Pankaj Kumar Parhi Satyanarayan Bramha 《Environmental monitoring and assessment》2013,185(8):6719-6737
In the present study, concentration of some selected trace metals (Fe, Mn, Ni, Co, Pb, Zn, Cu, Cr and Cd) are measured in Brahmani, Baitarani river complex along with Dhamara estuary and its near shore. Chemical partitioning has been made to establish association of metals into different geochemical phases. The exchangeable fraction is having high environmental risk among non-lithogeneous phases due to greater potential for mobility into pore water. The metals with highest bio-availability being Cd, Zn and Cr. The metals like Mn, Zn, Cd and Cu represent an appreciable portion in carbonate phase. Fe–Mn oxides act as efficient scavenger for most of the metals playing a prime role in controlling their fate and transport. Among non-lithogeneous phases apart from reducible, Cr showed a significant enrichment in organic phase. Risk assessment code values indicate that all metals except Fe fall under medium-risk zone. In estuarine zone Cd, Zn, Pb and Cr are released to 32.43, 26.10, 21.81 and 20 %, respectively, indicating their significant bio-availability pose high ecological risk. A quantitative approach has been made through the use of different risk indices like enrichment factor, geo-accumulation index and pollution load index. Factor analysis indicates that in riverine zone, Fe–Mn oxides/hydroxides seem to play an important role in scavenging metals, in estuarine zone, organic precipitation and adsorption to the fine silt and clay particles while in coastal zone, co-precipitation with Fe could be the mechanism for the same. Canonical discriminant function indicates that it is highly successful in discriminating the groups as predicted. 相似文献
826.
Dev K. Mandal Haripada Bhunia Pramod K. Bajpai Anil Kumar Gaurav Madhu Golok B. Nando 《Journal of Polymers and the Environment》2018,26(3):1061-1071
The biodegradability of calcium stearate (CaSt) and cobalt stearate (CoSt) filled polypropylene (PP) films were investigated in this work. The PP films were prepared using melt blending technique followed by hot press moulding. On the basis of their tensile properties, the optimum amount of pro-oxidants was taken as 0.2 phr. Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used for the characterization of optimized films. Presence of pro-oxidant in the PP was confirmed by the FTIR studies. Addition of pro-oxidants in the films decreased the thermal stability as revealed by TGA analysis. Crystallinity of the pro-oxidant filled PP decreased with addition of pro-oxidants as showen by DSC. The maximum biodegradation of CaSt and CoSt containing PP films was showen 7.65 and 8.34%, respectively with 0.2 phr. Both the microbial test and plant growth test (on corn and tomato) indicated that biodegradation intermediates were non toxic. 相似文献
827.
Kumar Vinay Dwivedi Shiv Kumar 《Environmental science and pollution research international》2021,28(9):10375-10412
Environmental Science and Pollution Research - Industrial processes and mining of coal and metal ores are generating a number of threats by polluting natural water bodies. Contamination of heavy... 相似文献
828.
John A. Simon Stew Abrams Tim Bradburne Dan Bryant Matthew Burns Daniel Cassidy John Cherry Sheau‐Yun Chiang Douglas Cox Michelle Crimi Elizabeth Denly Bill DiGuiseppi Jim Fenstermacher Stephanie Fiorenza Joseph Guarnaccia Nathan Hagelin Linda Hall John Hesemann Erika Houtz Stephen S. Koenigsberg Francois Lauzon Jeffrey Longsworth Tom Maher Angus McGrath Ravi Naidu Charles J. Newell Beth L. Parker Tadbir Singh Paul Tomiczek Rick Wice 《补救:环境净化治理成本、技术与工艺杂志》2019,29(4):31-48
Sixty leading members of the scientific, engineering, regulatory, and legal communities assembled for the PFAS Experts Symposium in Arlington, Virginia on May 20 and 21, 2019 to discuss issues related to per‐ and polyfluoroalkyl substances (PFAS) based on the quickly evolving developments of PFAS regulations, chemistry and analytics, transport and fate concepts, toxicology, and remediation technologies. The Symposium created a venue for experts with various specialized skills to provide opinions and trade perspectives on existing and new approaches to PFAS assessment and remediation in light of lessons learned managing other contaminants encountered over the past four decades. The following summarizes several consensus points developed as an outcome of the Symposium:
- Regulatory and policy issues: The response by many states and the US Environmental Protection Agency (USEPA) to media exposure and public pressure related to PFAS contamination is to relatively quickly initiate programs to regulate PFAS sites. This includes the USEPA establishing relatively low lifetime health advisory levels for PFAS in drinking water and even more stringent guidance and standards in several states. In addition, if PFAS are designated as hazardous substances at the federal level, as proposed by several Congressional bills, there could be wide‐reaching effects including listing of new Superfund sites solely for PFAS, application of stringent state standards, additional characterization and remediation at existing sites, reopening of closed sites, and cost renegotiation among PRPs.
- Chemistry and analytics: PFAS analysis is confounded by the lack of regulatory‐approved methods for most PFAS in water and all PFAS in solid media and air, interference with current water‐based analytical methods if samples contain high levels of suspended solids, and sample collection and analytical interference due to the presence of PFAS in common consumer products, sampling equipment, and laboratory materials.
- Toxicology and risk: Uncertainties remain related to human health and ecological effects for most PFAS; however, regulatory standards and guidance are being established incorporating safety factors that result in part per trillion (ppt) cleanup objectives. Given the thousands of PFAS that may be present in the environment, a more appropriate paradigm may be to develop toxicity criteria for groups of PFAS rather than individual PFAS.
- Transport and fate: The recalcitrance of many perfluoroalkyl compounds and the capability of some fluorotelomers to transform into perfluoroalkyl compounds complicate conceptual site models at many PFAS sites, particularly those involving complex mixtures, such as firefighting foams. Research is warranted to better understand the physicochemical properties and corresponding transport and fate of most PFAS, of branched and linear isomers of the same compounds, and of the interactions of PFAS with other co‐contaminants such as nonaqueous phase liquids. Many PFAS exhibit complex transport mechanisms, particularly at the air/water interface, and it is uncertain whether traditional transport principles apply to the ppt levels important to PFAS projects. Existing analytical methods are sufficient when combined with the many advances in site characterization techniques to move rapidly forward at selected sites to develop and test process‐based conceptual site models.
- Existing remediation technologies and research: Current technologies largely focus on separation (sorption, ion exchange, or sequestration). Due to diversity in PFAS properties, effective treatment will likely require treatment trains. Monitored natural attenuation will not likely involve destructive reactions, but be driven by processes such as matrix diffusion, sorption, dispersion, and dilution.
829.
830.