全文获取类型
收费全文 | 548篇 |
免费 | 13篇 |
专业分类
化学工业 | 79篇 |
金属工艺 | 9篇 |
机械仪表 | 12篇 |
建筑科学 | 8篇 |
能源动力 | 6篇 |
轻工业 | 41篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 41篇 |
一般工业技术 | 120篇 |
冶金工业 | 136篇 |
原子能技术 | 27篇 |
自动化技术 | 75篇 |
出版年
2022年 | 5篇 |
2021年 | 8篇 |
2020年 | 4篇 |
2018年 | 6篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 13篇 |
2013年 | 26篇 |
2012年 | 28篇 |
2011年 | 22篇 |
2010年 | 17篇 |
2009年 | 19篇 |
2008年 | 21篇 |
2007年 | 15篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 16篇 |
2003年 | 11篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 13篇 |
1999年 | 11篇 |
1998年 | 36篇 |
1997年 | 26篇 |
1996年 | 14篇 |
1995年 | 14篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 9篇 |
1989年 | 4篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 6篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1982年 | 5篇 |
1981年 | 4篇 |
1980年 | 7篇 |
1979年 | 6篇 |
1977年 | 4篇 |
1976年 | 10篇 |
1975年 | 6篇 |
1973年 | 6篇 |
1969年 | 4篇 |
1967年 | 4篇 |
1965年 | 3篇 |
1908年 | 4篇 |
排序方式: 共有561条查询结果,搜索用时 15 毫秒
1.
2.
R Beyer H Burghardt R Reich E Thomas T Gessner D.R.T Zahn 《Microelectronics Reliability》1998,38(2):144
Thin SiO2 and SiOxNy layers were grown on silicon using Rapid Thermal Processing (RTP) in either O2 or N2O ambient. Subsequent annealing or nitridation was performed in order to improve the electrical stability. The composition of the films, in particular the incorporation of nitrogen and hydrogen, has been studied. We obtained the distribution of states at the Si/insulator interface through the evaluation of CV measurements and investigated the charge trapping in the layers analysing the voltage–time behaviour during Fowler–Nordheim constant current injection. Furthermore, assuming a trap assisted tunneling mechanism, the influence of near interface trap states on the current voltage characteristic was used to derive an effective insulator state distribution. 相似文献
3.
A procedure and underlying algorithm for extracting knowledge from production and inventory databases to support engineering management activities is described. The process searches for, detects and isolates behaviour patterns inherent in the data. It relates these patterns to production irregularities, suggests connections with specific causes and helps propose possible corrective or preventive actions. The approach is based on a four-phase procedure: (1) the decision-maker focuses on the subject or difficulty at issue, represented by a target concept; (2) the KEDB algorithm, based on a machine learning approach, processes the relevant database and provides knowledge characterizing and classifying the target concept; (3) the output is interpreted in Pareto fashion as a series of possible circumstances explaining the target concept behaviour; and (4) based on these causes, the decision-maker decides on possible corrective actions to improve the situation, or preventive actions to forestall unfavourable conditions. A case study based on an actual quality control database is detailed. 相似文献
4.
C Oddoux E Reich F Axelrod A Blumenfeld C Maayan S Slaugenhaupt J Gusella H Ostrer 《Canadian Metallurgical Quarterly》1995,15(9):817-826
Familial dysautonomia (FD), a recessively inherited disease, has been mapped to chromosome 9q31. Highly polymorphic dinucleotide repeat markers flanking the genetic locus and at the same genetic location have been identified. We describe the prenatal diagnosis of FD using linkage and linkage disequilibrium analyses with these markers. Twelve families were analysed for informativeness and of these, seven went on to have prenatal testing (a total of eight fetuses tested). All of these fetuses were predicted to be heterozygous unaffected (FD carriers). Seven fetuses have come to term and are normal. In the absence of a recombinant proband, a panel of three proximal and three distal markers is sufficient to provide informative flanking markers and an 87-96 per cent likelihood of a highly predictive test. In an additional family at 1:4 risk for FD, no DNA was available from the propositus. This family was analysed using linkage disequilibrium to the #18 allele of the tightly linked marker D9S58 in conjunction with linkage analysis using data from two unaffected children. Prenatal diagnosis in this family indicated an affected fetus. 相似文献
5.
A. Krell T. Reich A. Beger G. A. Gogotsi Y. L. Groushevsky 《Journal of Materials Science》1991,26(17):4637-4642
At room temperature, SiO2 additions may increase the fracture toughness, K
IC, by diminishing the tetragonal phase contents to about 50%, but with ground surfaces the influence on strength is small.
A pronounced decrease in strength is observed with rising temperature in the high toughness region from 20°C to M
s, the starting temperature for martensitic transformation. Beyond M
s at lower toughness, the strength behaviour is very similar to nontransforming alumina ceramics, and an even modest increase
of the silicate concentration intensively promotes propagation-controlled failure in the brittle creep region (> 900°C) and
inelastic deformation. With less than 1% amorphous grain boundary phases, damage-free superplasticity is restricted to small
strains of less than 10%. The significance of high-temperature data for tool applications is considered by cutting tests with
high feeding rates. 相似文献
6.
W. Klas U. Herpers M. Reich R. Michel R. Droste R. Holm E.-M. Horn G. Müller 《工业材料与腐蚀》1991,42(11):570-575
The radiotracer technique as a means to investigate the corrosion of zirconium, tantalum, and a Ta-40Nb alloy in fluoride containing azeotropic nitric acid Zirconium and tantalum as well as the tantalum 40% niobium alloy are of considerable technical importance due to their high corrosion resistance against numerous corrosive media. With respect to corrosion testing in analytically pure azeotropic nitric acid in the temperature range between 20 and 121°C, corrosion rates were determined for zirconium: 7 · 10?6 to 5 · 10?4 mm/y, for tantalum: 10?8 to 4 · 10?6 mm/y, and for the Ta-40Nb alloy: 2 · 10?7 to 8 · 10?6 mm/y [1]. These corrosion rates will be markedly increased by adding small amounts of fluorides or by fluoride impurities. The radiotracer method after neutron activation was applied to determine the corrosion rates in azeotropic fluoride containing nitric acid. Even minute additions of fluorides strongly affect the corrosion resistance of zirconium. In the range between 0.15 and 10 ppm F? and at a temperature of 108°C, corrosion rates between 5.3 · 10?3 and 3.1 mm/y were measured. It was impossible to establish a limit for the fluoride concentration, below which the corrosion rate of zirconium will not be adversely influenced. The corrosion rates of tantalum and the Ta-40Nb alloy are considerably increasing above a fluoride concentration of 10 ppm. The highest corrosion rates measured were between 8.4 · 10?3 mm/y at 50°C/280 ppm F? and 1.4 · 10?2 mm/y at 110°C/320 ppm F?. Within the range of this investigation, the corrosion resistance of tantalum was higher than that of the Ta-40Nb alloy by one order of magnitude. The corrosion resistance of zirconium and tantalum was not influenced by any treatment of the samples before testing. 相似文献
7.
S. Reich 《Journal of Materials Science》1987,22(9):3391-3394
Bare and copper-coated polystyrene (PS) beads are mixed to give various volume fractions of electrically conducting and insulating spheres. This random mixture is subsequently sintered under pressure in a hot dye. The resulting solid is a polymer body in which thin (0.3 m) copper shells form a tightly packed cellular cluster which exhibits electrical continuity. This continuity is detected by inductive coupling via eddy currents to a coil at r.f. frequency. The percolation threshold for both two- and three-dimensional systems is observed by changing the thickness of the samples in a range in which it is comparable to the size of the beads. The observed thresholds for percolation are in good agreement with the theory. 相似文献
8.
9.
Although client satisfaction surveys can assess client satisfaction with IT service quality, they cannot easily be used to pinpoint how internal IT behaviors influence client satisfaction and prescribe solutions. This research fills the gap by introducing a concept— IT Service Climate—and a validated ten-item instrument that significantly explained client ratings of IT service quality. We recommend this measure as an effective diagnostic tool for managers aiming to improve quality and client satisfaction. 相似文献
10.
To select an operating system, an organization must consider several essential characteristics during its initial evaluation process. The analytic hierarchy process (AHP) offers an appropriate solution; the author illustrates it with a realistic case study in which an organization evaluates and ranks Windows XP, Linux, and Mac OS X 10.4. 相似文献