全文获取类型
收费全文 | 189篇 |
免费 | 1篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 41篇 |
金属工艺 | 16篇 |
机械仪表 | 4篇 |
建筑科学 | 6篇 |
石油天然气 | 8篇 |
无线电 | 10篇 |
一般工业技术 | 49篇 |
冶金工业 | 47篇 |
原子能技术 | 2篇 |
自动化技术 | 3篇 |
出版年
2022年 | 7篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 7篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 6篇 |
2014年 | 12篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 13篇 |
2010年 | 8篇 |
2009年 | 4篇 |
2008年 | 7篇 |
2007年 | 14篇 |
2006年 | 6篇 |
2005年 | 6篇 |
2004年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 2篇 |
1997年 | 8篇 |
1996年 | 4篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1987年 | 3篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1975年 | 4篇 |
排序方式: 共有190条查询结果,搜索用时 14 毫秒
11.
A. D. Pogrebnjak V. M. Rogoz O. V. Bondar N. K. Erdybaeva S. V. Plotnikov 《Protection of Metals and Physical Chemistry of Surfaces》2016,52(5):802-813
This review summarizes the present-day achievements in the study of the structure and properties of protective nanocomposite coatings based on NbN, NbAlN, and NbSiN prepared by a variety of modern deposition techniques. It is shown that a change in deposition parameters has a significant effect on the phase composition of the coatings. Depending on the magnitude of negative potential on the substrate, the pressure of nitrogen or a nitrogen–argon mixture in the chamber, and the substrate temperature, it is possible to obtain coatings containing different phases, such as NbN and SiNx (Si3N4), AlN, and NbAl2N. It is found that, in the case of formation of the ε-NbN phase, the coatings become very hard; their hardness achieves values on the order of 53 GPa. At the same time, they remain thermally stable at temperatures of up to 600°C, chemically inert, and resistant to wear. The effect of the nanograin size, the volume fraction of boundaries and interfaces, and the point defect concentration on the physicomechanical properties of these coatings is described. Niobium nitride-based coatings can be used in superconducting systems and single-photon detectors; they are capable of operating under the action of strong magnetic fields of up to 20 T; they can be used in integrated logic circuits and applied as protective coatings of machine parts, edges of cutting tools, etc. 相似文献
12.
13.
14.
V. N. Eremenko T. Ya. Velikanova A. A. Bondar 《Powder Metallurgy and Metal Ceramics》1989,28(11):868-873
Translated from Poroshkovaya Metallurgiya, No. 11(323), pp. 46–52, November, 1989. 相似文献
15.
16.
17.
The fluorescent probe Prodan has been widely used as a probe of model and biological membranes. Its fluorescent maxima in phospholipid bilayers vary as a function of phase state, with maxima at 485 for the liquid crystal Lalpha, 435 nm for the gel L'beta, and 507 nm for the interdigitated gel LbetaI phase, with excitation at 359 nm. These spectral changes have been used for the detection of phase changes among these phases. In the present study, the fluorescent properties and partition coefficients of Prodan in model membranes of phosphatidylcholines and phosphatidylethanols have been studied as a function of lipid phase state and cholesterol content. It is shown that the Prodan spectrum in the presence of cholesterol no longer reflects the known phase state of the lipid; in each phase state, the presence of cholesterol leads to a spectrum with the maximum at 435 nm, characteristic of the noninterdigitated gel phase. The partition coefficient of Prodan into these lipids also varies with the phase state, giving values of 0.35 x 10(4) in the interdigitated gel, 1.8 x 10(4) in the noninterdigitated gel, and 7. 6 x 10(4) in the liquid crystal phase. In the presence of cholesterol these partition coefficients are increased to 13 x 10(4) for the liquid crystal and the gel phase, and 5.1 x 10(4) in the presence of 100 mg/ml ethanol. These results suggest that Prodan has preferential interactions with cholesterol, and is thus not a randomly distributed fluorescent reporter probe in membranes containing cholesterol. These results suggest that Prodan should be used only with great caution in complex lipid mixtures, particularly biological membranes. 相似文献
18.
A. V. Gritsiv A. A. Bondar T. Ya. Velikanova V. M. Vereshchak 《Powder Metallurgy and Metal Ceramics》1999,38(3-4):166-171
The phase diagram for the Cr−Re system has been derived from published data in conjunction with measurements on alloys cast
and annealed at subsolidus temperatures (XRD, metallography, microprobe analysis, and measurement of the temperature for the
onset of melting by the Pirani—Alterthum method). The phase equilibria at solidus temperatures have been determined from studies
on alloys annealed at those temperatures. Phase homogeneity regions on the solidus have been identified: for (Cr) up to 43
at.% Re, for the σ phase −50–72 at.%Re, and for (Re) up to 17 at.%Cr; temperatures have also been determined for the invariant
equilibria L+σ ⇆ (Cr) at 2150±15°C and L+(Re)⇆σ at 2335±15°C.
Institute for Problems of Materials Science, Ukraine National Academy of Sciences, Kiev. Translated from Poroshkovaya Metallurgiya,
Nos. 3–4(406), pp. 65–71, March–April, 1999. 相似文献
19.
20.
V. Z. Kubliy A. A. Bondar S. V. Utkin V. M. Petyukh S. I. Lysenko T. Ya. Velikanova 《Powder Metallurgy and Metal Ceramics》2008,47(3-4):211-222
The Mo-Ni-B alloys prepared by arc-melting are examined in as-cast and annealed states using x-ray diffraction, scanning electron microscopy with electron probe microanalysis, and differential thermal analysis. The temperatures of invariant equilibria are refined. The projections of liquidus and solidus surfaces are plotted for the Ni-rich region. 相似文献