全文获取类型
收费全文 | 403篇 |
免费 | 12篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 86篇 |
金属工艺 | 16篇 |
机械仪表 | 10篇 |
建筑科学 | 4篇 |
能源动力 | 8篇 |
轻工业 | 25篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 42篇 |
一般工业技术 | 119篇 |
冶金工业 | 41篇 |
原子能技术 | 2篇 |
自动化技术 | 55篇 |
出版年
2023年 | 4篇 |
2022年 | 14篇 |
2021年 | 7篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 11篇 |
2016年 | 12篇 |
2015年 | 9篇 |
2014年 | 18篇 |
2013年 | 27篇 |
2012年 | 17篇 |
2011年 | 12篇 |
2010年 | 8篇 |
2009年 | 5篇 |
2008年 | 11篇 |
2007年 | 12篇 |
2006年 | 15篇 |
2005年 | 10篇 |
2004年 | 11篇 |
2003年 | 10篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 14篇 |
1994年 | 7篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 7篇 |
1985年 | 3篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1976年 | 5篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1969年 | 4篇 |
排序方式: 共有416条查询结果,搜索用时 0 毫秒
411.
A numerical procedure, based on the parametric differentiation and implicit finite difference scheme, has been developed for a class of problems in the boundary-layer theory for saddle-point regions. Here, the results are presented for the case of a three-dimensional stagnation-point flow with massive blowing. The method compares very well with other methods for particular cases (zero or small mass blowing). Results emphasize that the present numerical procedure is well suited for the solution of saddle-point flows with massive blowing, which could not be solved by other methods. 相似文献
412.
The plasmid profiles of oxytetracycline- and streptomycin-resistant isolates of Aeromonas salmonicida, Vibrio anguillarum, and Vibrio ordalii were examined by agarose gel electrophoresis. Bacterial isolates were from disease outbreaks in fish on the Atlantic and Pacific coasts. Resistant isolates were examined when grown in the presence and absence of antibiotic. Alkaline lysis methods were used for plasmid isolation. Vibrio spp. were predominantly plasmidless, except for a 47-kilobase (kb) plasmid. Atlantic coast isolates of A. salmonicida possessed four or six plasmids, with four smaller plasmids ranging in size from 4.3 to 8.1 kb being consistently observed. The plasmid profiles of antibiotic-sensitive ATCC strains were identical. The plasmid profiles of the Pacific coast isolates of A. salmonicida varied slightly from those of the Atlantic coast isolates with six plasmids observed, ranging in size from 4.2 to 8.9 kb. Resistance to the antibiotics was not altered following plasmid curing experiments and resistance was not transferable to Escherichia coli. Thus, resistance to oxytetracycline and streptomycin did not appear to be plasmid mediated. 相似文献
413.
Explosive crystallization of rf-sputtered amorphous CdTe films 总被引:1,自引:0,他引:1
S. V. Krishnaswamy R. Messier P. Swab L. L. Tongson K. Vedam 《Journal of Electronic Materials》1981,10(3):433-443
Explosive crystallization of about 2-μm thick amorphous CdTe films prepared by rf-sputtering in an Ar-N2 ambient has been observed. The transformation can be initiated with or without external thermal or mechanical impulses depending
on the oxygen content of the films. The crystallization is accompanied by a light flash. X-ray diffraction, Auger analysis,
and resistivity measurements were made on these films to arrive at a qualitative model to explain the observations. 相似文献
414.
Monomeric products of the 5,6-dihydroxy-dihydrothymine type are produced in the DNA by both ultraviolet and ionizing radiations. The capacity of nuclear preparations from normal and Xeroderma pigmentosum (XP) cells (Complementation groups A, B, C and D) to excise such products from ultraviolet or gamma-irradiated T7DNA was comparable and was independent of radiation induced strand breaks. 相似文献
415.
Hassan K. Sreenath Kadambi R. Sudarshanakrishna Niranjan N. Prasad Krishnaswamy Santhanam 《Starch - St?rke》1996,48(2):72-76
The dietary fibers were mainly isolated from seed hull of field beans (Phaseolus vulgaris), waste pulp of pineapple (Ananas camosus) as well as from whole wheat flour and, the fiber yields were 16.8, 2.0 and 7.0g/100g, respectively. These isolated fibers were included in sponge cake preparation by partially replacing all-purpose flour (maida) by 5% (w/w). Cakes and cake batter were evaluated for pH change, specific gravity, volume, moisture content, and color. The sensory characteristics and volume of the cakes were not altered with the inclusion of isolated fiber in the cake. The sensory quality evaluation showed that the fiber incorporated cakes were acceptable similar to the cake without added fiber. Incorporation of various fibers in the cake preparation increased the total dietary fiber content of the product by 4-6%. 相似文献
416.
This work concerns a novel means to generate wholly thermoplastic composites based on low-melting thermoplastics reinforced with high-melting thermotropic liquid crystalline polymers (TLCPs). A novel dual extrusion process was employed to generate nylon-11 fibers that are reinforced with continuous fibrils of a hydroquinone-based liquid crystalline polyester (DuPont TLCP, HX8000). These composite fibers display tensile properties significantly higher than those predicted by composite theory. These fibers were subsequently woven into a fabric, which in turn serves as a composite preform. Several layers of the fabric preform were stacked and consolidated to yield a composite plaque. The consolidation was carried out at temperatures just high enough for nylon-11 to melt, but well below the melting temperature of HX8000. Fabric preform composites based on the composite fibers with ∼35 wt% HX8000 gave modulus values close to five and one half times that of nylon-11, and strength values approximately two and one half times that of nylon-11. The tensile and flexural properties of these composites are superior to continuous glass-fiber reinforced composites at comparable loadings on a volume basis. Moreover, as the reinforcing fibrils are already encapsulated by the matrix, fiber wetting and fabric impregnation issues that are critical in the fabrication of continuous glass and carbon fiber composites are eliminated. 相似文献