全文获取类型
收费全文 | 1619篇 |
免费 | 82篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 37篇 |
化学工业 | 293篇 |
金属工艺 | 36篇 |
机械仪表 | 15篇 |
建筑科学 | 32篇 |
矿业工程 | 1篇 |
能源动力 | 50篇 |
轻工业 | 203篇 |
水利工程 | 8篇 |
石油天然气 | 3篇 |
无线电 | 173篇 |
一般工业技术 | 208篇 |
冶金工业 | 376篇 |
原子能技术 | 6篇 |
自动化技术 | 261篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 22篇 |
2020年 | 19篇 |
2019年 | 32篇 |
2018年 | 40篇 |
2017年 | 38篇 |
2016年 | 51篇 |
2015年 | 23篇 |
2014年 | 50篇 |
2013年 | 82篇 |
2012年 | 70篇 |
2011年 | 83篇 |
2010年 | 70篇 |
2009年 | 53篇 |
2008年 | 72篇 |
2007年 | 65篇 |
2006年 | 56篇 |
2005年 | 50篇 |
2004年 | 50篇 |
2003年 | 39篇 |
2002年 | 37篇 |
2001年 | 30篇 |
2000年 | 33篇 |
1999年 | 40篇 |
1998年 | 140篇 |
1997年 | 84篇 |
1996年 | 65篇 |
1995年 | 31篇 |
1994年 | 30篇 |
1993年 | 37篇 |
1992年 | 14篇 |
1991年 | 17篇 |
1990年 | 15篇 |
1989年 | 12篇 |
1988年 | 11篇 |
1987年 | 8篇 |
1986年 | 11篇 |
1985年 | 6篇 |
1984年 | 13篇 |
1983年 | 12篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1976年 | 16篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 5篇 |
排序方式: 共有1702条查询结果,搜索用时 15 毫秒
51.
Synthetic Modular Antibody Construction by Using the SpyTag/SpyCatcher Protein-Ligase System
下载免费PDF全文
![点击此处可从《Chembiochem : a European journal of chemical biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Dr. Md Kausar Alam Carolina Gonzalez Wayne Hill Dr. Ayman El-Sayed Dr. Humphrey Fonge Dr. Kris Barreto Prof. Dr. C. Ronald Geyer 《Chembiochem : a European journal of chemical biology》2017,18(22):2217-2221
Efforts to engineer recombinant antibodies for specific diagnostic and therapy applications are time consuming and expensive, as each new recombinant antibody needs to be optimized for expression, stability, bio-distribution, and pharmacokinetics. We have developed a new way to construct recombinant antibody-like “devices” by using a bottom-up approach to build them from well-behaved discrete recombinant antibody domains or “parts”. Studies on antibody structure and function have identified antibody constant and variable domains with specific functions that can be expressed in isolation. We used the SpyTag/SpyCatcher protein ligase to join these parts together, thereby creating devices with desired properties based on summed properties of parts and in configurations that cannot be obtained by using genetic engineering. This strategy will create optimized recombinant antibody devices at reduced costs and with shortened development times. 相似文献
52.
Angélica R. Jiménez‐Sánchez Israel Santillán Juvenal Rodriguez Resendiz Carlos A. Gonzalez‐Gutierrez Jorge D. Mendiola‐Santibañez 《International journal of imaging systems and technology》2012,22(2):137-144
In this article, a morphological contrast index based on the Weber's law is proposed to quantify the contrast in a processed image. This measure involves the contours of the image along with its background. The proposal made here is applied to detect the image with higher contrast, and also identify the enhanced image most similar to the original. Moreover, the contrast index is compared with other four indexes reported in the current literature. © 2012 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 22, 137–144, 2012 相似文献
53.
The aim of this paper is to review some of the parameters influencing the corrosivity of alkanolamine solvents used for natural gas purification or for CO2 capture. In the light of literature data and of new experimental results, the influences of temperature and of acid gas loading are discussed. These two parameters appear to have a strong impact on corrosion rates of carbon steel, with extrapolated corrosion rates of several tens of mm/year for the highest temperature and acid gas loading condition. It is then proposed to discuss about similarities and differences between natural gas processing and CO2 capture from flue gas. For both applications, alkanolamine processes are used. Still, differences can be found in operating parameters. The most significant gap concerns the lean amine sections. In acid gas treatment, the regeneration of the solvent is often performed down to zero loading. Under these conditions, an extremely low corrosivity of the lean solvent is expected. On the contrary, CO2 capture from flue gas requires only a partial stripping of the CO2 in the regeneration section, due to energy efficiency reasons. Then, the lean solvent still contains some acid gas, and subsequently a higher corrosivity. Finally, the general principles for material selection for the different parts of acid gas removal units are discussed, considering both cases of natural gas processing or CO2 capture. 相似文献
54.
Manganese peroxidase and biomimetic systems applied to in vitro lignin degradation in Eucalyptus grandis milled wood and kraft pulps
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
55.
56.
Christiane Chbib Adam J. Sobczak Mukesh Mudgal Cesar Gonzalez Daniel Lumpuy Justyna Nagaj 《Journal of Sulfur Chemistry》2016,37(3):307-327
4-C-Alkyl/aryl-S-ribosylhomocysteine (SRH) analogues were prepared by coupling of homocysteine with 4-substituted ribofuranose derivatives. The diastereoselective incorporation of the methyl substituent into the 4 position of the ribose ring was accomplished by the addition of methylmagnesium bromide to the protected ribitol-4-ulose yielding the 4-C-methylribitol in 85% yield as single 4R diastereomer. The 4-C hexyl, octyl, vinyl, and aryl ribitols were prepared analogously. Chelation controlled addition of a carbanion to ketones from the Si-face was responsible for the observed stereochemical outcome. Oxidation of the primary alcohol of the 4-C ribitols with catalytic amounts of tetrapropylammonium perruthenate in the presence of N-methylmorpholine N-oxide produced 4-C-alkylribono-1,4-lactones in high yields. Mesylation of the latter compounds at the 5-hydroxyl position and treatment with a protected homocysteine thiolate afforded protected 4-C-alkyl/aryl-SRH analogues as the lactones. Reduction with lithium triethylborohydride and successive global deprotections with TFA afforded 4-C-alkyl/aryl SRH analogues. These analogues might impede the S-ribosylhomocysteinase(LuxS)-catalyzed reaction by preventing β-elimination of a homocysteine molecule, and thus depleting the production of quorum sensing signaling molecule AI-2. 相似文献
57.
58.
A. Gonzalez del Campo P. Cañizares J. Lobato M.A. Rodrigo F.J. Fernandez 《International Journal of Hydrogen Energy》2012
In this work, the potential application of bio-hydrogen in a fuel cell was studied. To do that an activated sludge was acclimatized to an acidogenic culture producing bio-hydrogen. Once reached the steady state, several batch experiments were carried out by feeding a synthetic fruit juice industry wastewater to the acidogenic culture. The bio-hydrogen yield obtained when this synthetic fruit juice industry wastewater was fed was 1403 mol H2/mol hexose and the hydrogen percent in gas phase was 57%. In an average size fruit juice industry, this bio-hydrogen yield corresponds to a bio-hydrogen production of about 6000 mol H2/d. In the subsequent stage, a synthetic bio-hydrogen stream with the same composition of the cleaned bio-hydrogen obtained in the acidogenic fermentation was fed as fuel in a Fuel Cell, obtaining very similar power and polarization curves than that obtained when feeding pure hydrogen, differences lower than 10%. These results showed that the hydrogen stream obtained by the acidogenic fermentation could be used to produce electricity in a high temperature PEMFC. 相似文献
59.
M.A. Heckman K. Sherry E. Gonzalez De Mejia 《Comprehensive Reviews in Food Science and Food Safety》2010,9(3):303-317
ABSTRACT: The consumption of energy drinks is rapidly increasing, as demonstrated by their large market growth. The targeted demographic group is teenagers, young adults, 18 to 34 y old; although expansion into nontraditional markets is also occurring. It is claimed that energy drinks can offer an increased energy boost related to their ingredient profile of caffeine, taurine, herbal extracts, and vitamins. Research suggests that energy drink formulations, in addition to increasing energy utilization, may also improve mood, enhance physical endurance, reduce mental fatigue, and increase reaction time. However, in most cases, the corresponding mechanisms of action are not clear. In addition, concerns have been raised over their safety and with a currently weak regulatory environment, efforts need to be made to ensure consumer safety. The objective of this article is to review the current U.S. energy drink market with emphasis on its market size, target demographic, active ingredients, potential benefits, safety, and regulations. 相似文献