全文获取类型
收费全文 | 204篇 |
免费 | 0篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 9篇 |
机械仪表 | 2篇 |
建筑科学 | 3篇 |
能源动力 | 9篇 |
轻工业 | 9篇 |
石油天然气 | 4篇 |
无线电 | 7篇 |
一般工业技术 | 12篇 |
冶金工业 | 137篇 |
自动化技术 | 10篇 |
出版年
2015年 | 2篇 |
2013年 | 4篇 |
2012年 | 1篇 |
2011年 | 1篇 |
2010年 | 3篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 6篇 |
2006年 | 1篇 |
2004年 | 1篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 28篇 |
1997年 | 19篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 11篇 |
1992年 | 8篇 |
1991年 | 5篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 3篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1961年 | 1篇 |
1957年 | 1篇 |
1931年 | 1篇 |
排序方式: 共有204条查询结果,搜索用时 15 毫秒
31.
If carefully planned for and managed, turnkey graphics can boost the productivity of design and drafting departments. 相似文献
32.
EM Cornford S Hyman ME Cornford RT Damian MJ Raleigh 《Canadian Metallurgical Quarterly》1998,57(7):699-713
Cellular distribution of the Glut1 glucose transporter in normal primate brains was analyzed by immunogold electron microscopy. Two configurations of endothelial Glut1 glucose transporter (high and low density capillaries) have been found in resections of traumatically injured and epileptogenic human brain; the objective of the present study was to ascertain whether these same 2 capillary populations, expressing high and low glucose transporter densities, were the common configuration in normal brain. The relative numbers of Glut1 glucose transporter-associated gold particles on luminal and abluminal endothelial cell membranes were determined within the cerebral cortex of several normal, nonhuman primates. Low Glut1 densities were seen in brain endothelia of both the rhesus and squirrel monkey cortex, with slightly greater quantities of Glut1 in vervet monkey cortices. The Glut1 transporter was most highly expressed in the baboon cortex, approaching the concentrations seen in human brains. In the rhesus, squirrel, and vervet monkeys, Glut1 concentrations were greater on the abluminal than luminal capillary membranes. In contrast, mean luminal membrane Glut1 concentrations were greater in baboons, resembling the distribution seen in the human brain. Brain regional differences in transporter concentration were seen in comparing membrane densities in the baboon cortex (approximately 15 Glut1-gold particles per micrometer), hippocampus (approximately 12 Glut1 gold particles per micrometer), cerebellum (approximately 6 Glut1-gold particles per micrometer), and retinal microvasculature (approximately 20 Glut1-gold particles per micrometer). We conclude that a single, uniform Glut1 distribution characterizes brain capillaries of normal nonhuman primates, and hypothesize that the presence of high and low density glucose transporter endothelial cells (seen in human traumatic injury and seizure resections) represents a pathologic response to brain insult. 相似文献
33.
34.
35.
In this paper, we have examined the recovery of current leads for superconducting magnets after loss of coolant. It is found that if a lead is without cooling for longer than a time τmax, thermal runaway can be prevented by an increase in cooling or a decrease in current through the lead. It is evident that designing a lead away from its optimal values can make the lead significantly less susceptible to problems of thermal runaway. 相似文献
36.
37.
The mechanical behavior of a wrought high strength aluminum alloy is examined as a function of the concentration of second-phase
microconstituents. These second-phase particles are located in grain boundaries and interdendritic sites. Their concentration
was varied by thermal-mechanical processing. In the areas of strengths, ductility, crack toughness, fatigue, and stress corrosion
cracking, empirical results are presented and discussed. Observations are made on changes in the anisotropic character of
this category of material with lower concentrations of second phases.
Formerly Research Advisor, Frankford Arsenal.
This paper is based on an invited talk presented at a symposium on Homogenization of Alloys, sponsored by the IMD Heat Treatment
Committee, and held on May 11,1970, at the spring meeting of The Metallurgical Society of AIME, in Las Vegas, Nev. 相似文献
38.
Hyman D. Gesser Om Vaidya W. George Baldwin Arthur Chow Ernest Bock David W. McBride 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1980,30(1):415-422
The gaseous reduction of gallium in white mica has been studied using natural gas as the reducing gas. From a study at three temperatures, the initial extraction was observed to be linear with time and independent of particle size. The results suggest that delamination of the mica lattice is important. The measured activation energy for the loss of gallium from the white mica is 184 × 21 kJ mol?1. 相似文献
39.
Phosphorylation of both tyrosine and serine residues of focal adhesion kinase (FAK) was stimulated by the adhesion of BALB/c mouse 3T3 cells to fibronectin, but phosphorylation of threonine was not detectable. Acidic and basic fibroblast growth factors also stimulated the phosphorylation of serine and tyrosine of FAK in cells adhered to poly-L-lysine, but epidermal growth factor and platelet-derived growth factor did not. A fusion protein of fibronectin and basic fibroblast growth factor effectively induced the phosphorylation of FAK. Phosphorylation of FAK in the rat myoblast L-6 cell line, which lacks fibroblast growth factor receptors, was not stimulated by fibroblast growth factors, suggesting that the interaction of fibroblast growth factors with their receptors might cause the phosphorylation of FAK. 相似文献
40.
Stimulated Raman scattering (SRS) experiments in hydrogen have been performed with a collimated beam from ane -beam pumped XeF laser operating at 353 nm. An unstable resonator provided good beam quality at energies of about 1.2 J and pulse lengths of about 320 ns. A folded-path Raman cell allowed cell lengths to be continuously varied up to 11 m at a hydrogen pressure of 10 atm. Energy conversion efficiencies of >45 percent to first Stokes (S1 ) at 414 nm and >40 percent to second Stokes (S2 ) at 500 nm were observed with no indication of significant four-wave processes. 相似文献