全文获取类型
收费全文 | 190篇 |
免费 | 8篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 24篇 |
金属工艺 | 3篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
能源动力 | 3篇 |
轻工业 | 7篇 |
石油天然气 | 6篇 |
无线电 | 42篇 |
一般工业技术 | 27篇 |
冶金工业 | 51篇 |
自动化技术 | 29篇 |
出版年
2023年 | 1篇 |
2021年 | 6篇 |
2020年 | 4篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 2篇 |
2014年 | 5篇 |
2013年 | 9篇 |
2012年 | 5篇 |
2011年 | 9篇 |
2010年 | 9篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 4篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1998年 | 20篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1983年 | 1篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
1964年 | 3篇 |
1963年 | 1篇 |
排序方式: 共有198条查询结果,搜索用时 515 毫秒
61.
62.
A new technique, whereby the so-called "iso-directional-force lines" may be illustrated directly, is proposed. The method is based on the levitation forces acting on a particle immersed in paramagnetic fluid in nonhomogeneous magnetic field. An ordered set of capillaries, each containing a small particle suspended in the fluid, may be used to depict the iso-directional-force lines by the equilibrium positions of the particles. Once the field is mapped (by a selected standard system), its characteristics are known, with respect to any other fluid particle combinations. The latter is of significance for research and technology. 相似文献
63.
64.
Simone L. Yaniv A. Sawla M. Peters 《Journal of research of the National Institute of Standards and Technology》1991,96(5):529-540
A comparison of force measurements performed at the National Institute of Standards and Technology, USA, and at the Physikalisch-Technische Bundesanstalt, Germany is reported. The focus of the study was the intercomparison of the forces realized by the two Institutes rather than the measurement process. The transfer standards used in the comparison consisted of force transducers and associated readout instrumentation. The results of the intercomparison reveal that over a range of 50 kN to 4.5 MN, the forces realized at NIST and at PTB compare favorably. For forces up to 900 kN the agreement is within ±40 ppm; above 900 kN the agreement is within ± 100 ppm. 相似文献
65.
A theory of second-viscosity phenomena in dilute solutions of3He in superfluid4He is presented. The theory considers only phonon and3He quasiparticle excitations and is therefore valid at temperatures below about 0.6 K. It is shown, by an exact calculation, that within the framework of the Landau-Pomeranchuck model for the3He quasiparticle excitation energy, the four second-viscosity coefficients are related to one another and that only one of them is actually an independent kinetic coefficient. The relations between the second-viscosity coefficients are applied to analyze the expressions for the dissipative function and the first- and the second-sound attenuation coefficients. It is shown that the second-viscosity contribution to the second-sound attenuation is smaller by an order of magnitude than its contribution to the first-sound attenuation. 相似文献
66.
Avishay Yaniv 《Journal of Low Temperature Physics》1973,13(1-2):105-111
A theory of the nuclear magnetic susceptibility of dilute solutions of
3
He in
4
He at low temperatures is presented. It is shown that
–1
is a linear function of the corresponding inverse free fermion magnetic susceptibility. It is also shown that the experimental Curie constant differs from the theoretical one by an amount which is of the order of the
3
He concentration. It follows that the existing experimental results are not adequate for the calculation of the Fermi liquid magnetic susceptibility enhancement factor. 相似文献
67.
68.
Doron Kornreich Yaniv Benbenisti H.B. Mitchell Paul Schaefer 《Signal Processing: Image Communication》1997,10(4):269-278
Recently multilayer neural networks have been used for still picture compression. In these networks it is necessary to normalize the gray levels in the input picture before they are fed into the neural network. In this paper we investigate six different normalization functions, of which four are new and appear for the first time in this paper. We show that the compression efficiency of a neural network depends on the normalization function used and that the new normalization functions consistently outperform the traditional normalization functions. 相似文献
69.
70.
Induction of tolerance by IL-10-treated dendritic cells 总被引:1,自引:0,他引:1
K Steinbrink M W?lfl H Jonuleit J Knop AH Enk 《Canadian Metallurgical Quarterly》1997,159(10):4772-4780
Dendritic cells (DC) form a specialized system for presenting Ag to naive or quiescent T cells and consequently play a central role in the induction of T and B cell immunity. In this study we used DC generated from peripheral progenitors to analyze the effect of IL-10 on the accessory function of human DC. We demonstrate that immature DC, harvested on days 9 to 11 and exposed to IL-10 for the last 2 days of culture, show a strongly reduced capacity to stimulate a CD4+ T cell response in an allogeneic MLR in a dose-dependent manner. In contrast, fully mature DC are completely resistant to the effects of IL-10. These results were obtained in both an alloantigen-induced MLR and an anti-CD3 mAb-induced response of primed and naive (CD45RA+) CD4+ T cells. FACS analysis revealed inhibition of the up-regulation of the costimulatory molecules CD58 and CD86 and the specific DC marker CD83 in DC pretreated with IL-10. These data suggest that IL-10 inhibited the development of fully mature DC. Furthermore, DC precultured with IL-10, but not controls, induced a state of alloantigen-specific anergy in CD4+ T cells and of peptide-specific anergy in the influenza hemagglutinin-specific T cell clone HA1.7. Analysis of the supernatants of these anergic T cells revealed a reduced production of IL-2 and IFN-gamma compared with that in control cells. Collectively, these data suggest that IL-10 converts immature DC into tolerogenic APC, which might be a useful tool in the therapy of patients with autoimmune or allergic diseases. 相似文献