全文获取类型
收费全文 | 332篇 |
免费 | 12篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 14篇 |
化学工业 | 52篇 |
金属工艺 | 4篇 |
机械仪表 | 5篇 |
建筑科学 | 14篇 |
矿业工程 | 7篇 |
能源动力 | 24篇 |
轻工业 | 16篇 |
水利工程 | 4篇 |
石油天然气 | 6篇 |
无线电 | 51篇 |
一般工业技术 | 51篇 |
冶金工业 | 82篇 |
自动化技术 | 26篇 |
出版年
2023年 | 6篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 7篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 16篇 |
2011年 | 22篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 10篇 |
2007年 | 8篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 7篇 |
1998年 | 22篇 |
1997年 | 15篇 |
1996年 | 8篇 |
1995年 | 12篇 |
1994年 | 5篇 |
1993年 | 3篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 5篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 5篇 |
1976年 | 2篇 |
1974年 | 2篇 |
1972年 | 3篇 |
1961年 | 1篇 |
1960年 | 1篇 |
1949年 | 1篇 |
1943年 | 1篇 |
排序方式: 共有356条查询结果,搜索用时 296 毫秒
21.
A human study of the effects of topical nystatin (Mycostatin) therapy of oral candidiasis showed that effects of treatment were limited to the time in which the drug was used. Two weeks of therapy resulted in significant reduction in number of organisms and marked improvement in signs and symptoms of candidiasis. The condition recurred rapidly following cessation of treatment. No change in specific anticandida antibody in saliva or in adherence of Candida albicans to mucosal epithelium (in vitro) was seen with treatment. 相似文献
22.
23.
Elliott MR Arbogast KB Menon R Durbin DR Winston FK 《Accident; analysis and prevention》2003,35(6):833-840
Estimated traveling speed and speed limit have typically been used in population-based surveillance data to estimate crash severity. The accuracy of these measures in predicting crash severity is unknown. The Partners for Child Passenger Safety (PCPS) surveillance system offers a unique opportunity to compare these measures, as well as a novel measure of crash severity, “self-report” delta-V, to the accepted measure of delta-V estimated during detailed crash-investigations in 118 crashes. This “self-report” delta-V was computed from the estimated traveling speeds and direction of impact obtained from telephone interviews with drivers. These “self-reported” delta-V estimates are modestly associated with crash-investigation delta-V estimates, with the degree of association a function of the direction of impact: when the respondent was struck from the rear, the degree of association is strong; frontal, side, and single-vehicle crashes yield weaker associations. This “self-reported” delta-V measure, however, is a substantial improvement over use of estimated traveling speed or speed limit only. 相似文献
24.
Lanlin Zhang In-Soo Park Krenar Shqau W. S. Winston Ho Henk Verweij 《JOM Journal of the Minerals, Metals and Materials Society》2009,61(4):61-71
Supported inorganic membranes hold the promise of highly effective separation and purification, and stable operation in harsh
environments. Examples are thin films of paladium alloy for H2, mixed conducting oxides for O2, amorphous silica for CO2 and zeolites for hydro-carbons, and meso-porous titania for water purification. However, compared to organic membranes, large-scale
production of inorganic membranes requires improvements in reproducibility and cost processes. This short overview provides
terminology, concepts, and important criteria for performance, stability, reproducibility, and cost of supported inorganic
membranes. Also discussed are possible approaches to address the challenges, and examples for designing gas separation and
water purification. 相似文献
25.
PURPOSE: To evaluate the efficacy of topical mitomycin C in treating conjunctival and corneal epithelial dysplasia and neoplasia. METHODS: Seven eyes of seven patients with conjunctival and corneal epithelial dysplasia and neoplasia were treated with one drop of topical mitomycin C 0.04% four times a day for 7 days in alternate weeks. The patients' charts were reviewed retrospectively. Patients with either multiple recurrences or extensive ocular surface involvement were treated. In all eyes, the diagnosis of epithelial dysplasia or neoplasia was confirmed by histopathology before the onset of therapy. Patients were examined at least every 14 days during treatment and examined at intervals after completion of treatment. RESULTS: With topical mitomycin C, six eyes of seven patients had complete clinical regression of their conjunctival and corneal epithelial dysplasia and neoplasia. One eye of one patient had partial clinical regression of conjunctival and corneal epithelial dysplasia. Follow-up after completion of topical mitomycin C therapy and excision of residual disease ranged from 2 to 16 months (mean, 9 months; SD, 4.3 months) and was without clinical sign of recurrence. Topical mitomycin C therapy was associated with transitory ocular discomfort, conjunctival injection, tearing, photophobia, and punctate epithelial keratopathy. CONCLUSION: In this small series of eyes, topical mitomycin C was effective as a treatment for conjunctival and corneal epithelial dysplasia and neoplasia. 相似文献
26.
Dong S. Park Michael J. McNallan Chan Park Winston W. Liang 《Journal of the American Ceramic Society》1990,73(5):1323-1329
The active corrosion of sintered α-silicon carbide from heat exchanger tubes in the temperature range 900° to 1100°C in gas mixtures containing 2% Cl2 by volume with additions of O2 or H2 has been investigated by thermogravimetric analysis and subsequent examination of the corrosion products. The presence of a small amount of oxygen accelerated rapid active corrosion in chlorine-containing gas mixtures, but the corrosion was suppressed by an active-to-passive transition when the concentration of oxygen in the gas mixture was too high. Low rates of attack were observed in the environments containing H2 even when the chlorine potential was high. The concentration of oxygen necessary to produce the active-to-passive transition was found to vary from one material to another and may be related to the amount of excess carbon in the sintered silicon carbide. 相似文献
27.
28.
Jie Zhong Shuquan Liang Juan Zhao Winston Duo Wu Wenjie Liu Huanting Wang Xiao Dong Chen Yi-Bing Cheng 《Journal of the European Ceramic Society》2012,32(12):3407-3414
Novel mesoporous TiC microspheres with uniform size are synthesized via a sol–gel combined carbothermal reduction process. A microfluidic aerosol nozzle was used to produce droplets which were subsequently dried into gel microspheres under different conditions. The influence of drying temperatures and sol aging time on the diameters of obtained gel microspheres was investigated. The spherical morphology of TiC spheres can be maintained after a two-step heat treatment. Moreover, the TiC microspheres exhibit a high surface area of 267 m2/g and consist of 30–50 nm nano TiC grains and 4.5 nm pores. This unique nanostructure is directly formed from the carbothermal reduction of non-porous and template-free titania/carbon spheres. 相似文献
29.
30.
Skim and whole milk powders were manufactured at lab scale by spray freeze drying (SFD), using liquid nitrogen as the cryogen. The polydispersity of droplet/particle sizes was limited using an encapsulator nozzle to atomize the feed. Particle morphology was examined using a scanning electron microscope. Samples were compared with equivalent spray-dried powders in tests of wettability and dissolution in water. The spray freeze-dried powders were found to be highly porous, with a uniform structure of pores throughout the entire particles. When tested in water, SFD skim milk powders wetted roughly three times as fast as industrially spray-dried agglomerated skim milk powders and were observed to dissolve rapidly by breaking down into smaller particles. 相似文献