全文获取类型
收费全文 | 170篇 |
免费 | 9篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 30篇 |
金属工艺 | 1篇 |
机械仪表 | 3篇 |
建筑科学 | 6篇 |
能源动力 | 8篇 |
轻工业 | 8篇 |
水利工程 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 49篇 |
冶金工业 | 43篇 |
原子能技术 | 3篇 |
自动化技术 | 16篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 3篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 14篇 |
2012年 | 12篇 |
2011年 | 11篇 |
2010年 | 2篇 |
2009年 | 8篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 12篇 |
2005年 | 5篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 9篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 6篇 |
1994年 | 4篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1978年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有179条查询结果,搜索用时 31 毫秒
1.
2.
Galen R. Hatfield Beili Li Willis B. Hammond Franz Reidinger John Yamanis 《Journal of Materials Science》1990,25(9):4032-4035
Lanthanum silicon nitride (LaSi3N5) powder has been prepared under the relatively mild conditions of 1400 ° C and 1 atm nitrogen. Chemical, X-ray diffraction, solid state nuclear magnetic resonance spectra and morphological information on this powder is presented. The X-ray diffraction data and previously published information have been used to develop a more complete specification of the unit cell dimensions.29Si magic-angle spinning nuclear magnetic resonance spectra of LaSi3N5 show two chemical shifts at –64.5 and –56.5 p.p.m. These shifts reflect two electronically different types of silicon which have been attributed to the effects of quadrupolar139La nuclei and their spatial arrangements around silicon atoms. 相似文献
3.
Various examples of composite titania-based nanostructured materials exhibiting cooperative functionalities between different active components are presented. The fabrication of these integrated composite materials is based on one-pot supramolecular templating techniques combined with acidic sol-gel chemistry. The defined 3-D nanoscale organization and integration of various functional components results in advanced optoelectronic and photonic applications such as visible light sensitization of mesoporous titania photocatalysts with cadmium sulfide nanocrystals acting as sensitizing integral part of the mesopore wall structure, narrow bandwidth emission from rare earth ion activated nanocrystalline mesoporous titania films, and mirrorless lasing in dye-doped hybrid organic/inorganic mesostructured titania waveguides. 相似文献
4.
In the present study, the affective impact of earcons on stimulus classification is investigated. We show, using a picture-categorization task, that the affective connotation of earcons in major and minor mode (representing positive and negative valence, respectively) can be congruent or incongruent with response valence. Twenty participants classified pictures of animals and instruments in 256 trials, using positive and negative Yes or No responses. Together with the pictures, either a chord in major mode or minor mode was played. The affective valence of the chords either did or did not match the valence of responses. Response-time latencies show congruency effects of the matching and non matching sound and response valences, indicating that it is important to carefully investigate human-computer interfaces for potential affective congruency effects, as these can either facilitate or inhibit user performance. 相似文献
5.
6.
Lu Shen Yusheng Zhao Ali Tekeei Fu‐Hung Hsieh Galen J. Suppes 《Polymer Engineering and Science》2014,54(7):1503-1511
A model based on about a dozen fundamental differential equations is used to evaluate and simulate the urethane reactions and physical processes of urethane box foaming. This work focuses on quantitative modeling of foam density for foams using water and physical blowing agents. The final densities of foams range from 30 to 90% of the density as projected with full utilization of the blowing agent. The primary sources of inefficient use of blowing agent are loss of the physical blowing during open‐air mixing and degassing—basically, physical blowing agents with boiling points between 25 and 80°C will evaporate and experience cell rupture in box foams. This loss of blowing agent would not apply to in‐line mixers used for commercial production and should be taken into account with scaling up box or cup foams commercial processes. POLYM. ENG. SCI., 54:1503–1511, 2014. © 2013 Society of Plastics Engineers 相似文献
7.
This paper describes the development of a new low-cost phase-change material packaging concept for air conditioning systems. The realization of the promise of storage assisted air conditioning for saving oil and money is dependent upon the successful development of a low-cost storage subsystem and the adoption of time-of-day electricity rates. Time-of-day rates are currently under consideration or have been adopted in 27 different states and consideration of these rates has been required by federal legislation. The adoption of this low-cost thermal energy storage technology for storage assisted air conditioning and other storage assisted heat pump applications has the potential of saving 100 million barrels of oil over the next ten years and 12 million barrels of oil per year by 1985. These savings would accrue from a change in the summer air conditioning peak electricity load from oil and gas-fired peak electrical generators to the base load electrical generators fired by coal, nuclear and hydroelectric. This low-cost air conditioning storage concept is based on hydrated salt phase change material, specifically a mixture based on sodium sulphate decahydrate and a new low-cost packaging technology which uses a film laminate as the phase change material mixture's package and heat exchanger. In this paper. the relative economics of various technological options for air conditioning storage are compared. It is demonstrated that this economic analysis leads to the necessity to develop a low-cost film package and heat exchanger. An analysis of savings to homeowners based on current and planned off-peak rates is included. Since this is the first product developed utilizing this new low-cost material as a packaging film, it is anticipated that major improvements in both cost and performance specifically related to individual systems will be developed and implemented over the next ten years, with significant improvements coming in the next several years. 相似文献
8.
9.
Noncatalytic alcoholysis kinetics of soybean oil 总被引:1,自引:0,他引:1
Mohanprasad?A.?Dasari Michael?J.?Goff Galen?J.?SuppesEmail author 《Journal of the American Oil Chemists' Society》2003,80(2):189-192
Reaction kinetics for the alcoholysis of soybean oil with methanol, ethanol, and isopropanol were evaluated in the absence
of catalyst. Metal reactor surfaces catalyzed these reactions, so the reactions were conducted in glass capillary tubes at
120, 150, and 180°C. The reactivity of the alcohols increased with decreasing carbon number. Higher temperatures promoted
faster reactions. Higher alcohol stoichiometries did not significantly increase reaction rates; this was attributed to the
limited solubility of the alcohol in the soybean oil. At less than 20% conversion, the solubility of the alcohol in the oil
phase continuously increased, resulting in increased reaction rates. At approximately 20% conversion, the reaction systems
became homogeneous until a glycerine phase was formed at high conversions. In addition to their fundamental value, these data
provided a basis on which catalytic reactions can be investigated between 100 and 200°C. 相似文献
10.
Yusheng Zhao Michael J. Gordon Ali Tekeei Fu‐Hung Hsieh Galen J. Suppes 《应用聚合物科学杂志》2013,130(2):1131-1138
A theoretical model was developed to simulate the polyurethane foaming process for a rigid foam. In the model, multiple ordinary differential equations were solved by MATLAB and the model was able to predict temperature profiles by inputting foam recipe information. This initial study on foam modeling focusses on reaction kinetic parameters that were fitted to experimental temperature data as a function of time. The modeling was able to accurately model temperature profiles of single‐polyol polyurethane formulations and was able to accurately predict temperature profiles of mixtures based on pure component kinetic parameters. A primary goal of this work is to expedite the ability to develop new foam formulations by simulation—especially for incorporation of new bio‐based polyols into formulations. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1131‐1138, 2013 相似文献