首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   221篇
  免费   2篇
电工技术   1篇
化学工业   18篇
金属工艺   11篇
机械仪表   17篇
建筑科学   1篇
矿业工程   1篇
能源动力   2篇
轻工业   1篇
水利工程   6篇
石油天然气   8篇
无线电   17篇
一般工业技术   67篇
冶金工业   42篇
原子能技术   12篇
自动化技术   19篇
  2021年   3篇
  2020年   2篇
  2019年   2篇
  2018年   7篇
  2017年   9篇
  2016年   7篇
  2015年   4篇
  2014年   9篇
  2013年   10篇
  2012年   5篇
  2011年   6篇
  2010年   4篇
  2009年   4篇
  2008年   3篇
  2007年   7篇
  2006年   12篇
  2005年   2篇
  2002年   4篇
  2000年   3篇
  1998年   7篇
  1997年   3篇
  1996年   8篇
  1995年   9篇
  1994年   4篇
  1993年   7篇
  1992年   6篇
  1991年   4篇
  1990年   3篇
  1989年   2篇
  1988年   2篇
  1987年   3篇
  1985年   3篇
  1984年   2篇
  1983年   2篇
  1981年   3篇
  1980年   4篇
  1979年   3篇
  1977年   2篇
  1976年   3篇
  1975年   4篇
  1973年   2篇
  1972年   4篇
  1970年   2篇
  1969年   3篇
  1968年   4篇
  1966年   2篇
  1963年   2篇
  1962年   3篇
  1961年   2篇
  1960年   1篇
排序方式: 共有223条查询结果,搜索用时 19 毫秒
91.
92.
A glycoprotein, with apparent molecular weight in SDS-polyacrylamide gels of 37 kDa, has been isolated from the excretory-secretory (ES) products of the adult stage of Trichostrongylus colubriformis, a parasitic nematode. This protein is the major ES product recognized in immunoblots by lymph from a naturally infected sheep. A synthetic oligonucleotide, based on peptide sequence data from a digest of the purified protein was used to successfully screen a cDNA library. A cDNA clone was isolated which encoded a presumptive protein precursor of 220 amino acids that contained a 63 amino acid region of which more than 35% of the residues were proline, three peptide sequences determined from the natural component, and three potential N-glycosylation sites, consistent with the protein being isolated from the lectin-bound fraction of the adult ES products. The presumptive, processed, amino terminus encoded by the cDNA clone was preceded by a signal-like, hydrophobic-rich region of 16 amino acids.  相似文献   
93.
94.
95.
96.
The authors give the results of an analytical and experimental investigation of heat transfer between an axisymmetric jet and a plate normal to the flow for laminar boundary layer conditions.  相似文献   
97.
The first step in determining whether a fluorescent dye can be used for antibody labeling consists in collecting data on its physical interaction with the latter. In the present study, the interaction between the 2-(2-hydroxy-5-nitrobenzylidene)-1,3-indanedione (HNBID) dye and the IgG1 monoclonal mouse antibody anti-human heart fatty acid binding protein (anti-hFABP) has been investigated by fluorescence and circular dichroism spectroscopies and complementary structural results were obtained by molecular modeling. We have determined the parameters characterizing this interaction, namely the quenching and binding constants, classes of binding sites, and excited state lifetimes, and we have predicted the localization of HNBID within the Fc region of anti-hFABP. The key glycosidic and amino acid residues in anti-hFABP interacting with HNBID have also been identified. A similar systematic study was undertaken for the well-known fluorescein isothiocyanate fluorophore, for comparison purposes. Our results recommend HNBID as a valuable alternative to fluorescein isothiocyanate for use as a fluorescent probe for IgG1 antibodies.  相似文献   
98.
Single nucleotide polymorphism (SNP) associations with milk production traits found to be significant in different screening experiments, including SNP in genes hypothesized to be in gene pathways affecting milk production, were tested in a validation population to confirm their association. In total, 423 SNP were genotyped across 411 Holstein bulls, and their association with 6 milk production traits--Australian Selection Index (indicating the profitability of an animal's milk production), protein, fat, and milk yields, and protein and fat composition--were tested using single SNP regressions. Seventy-two SNP were significantly associated with one or more of the traits; their effects were in the same direction as in the screening experiment and therefore their association was considered validated. An over-representation of SNP (43 of the 423) on chromosome 20 was observed, including a SNP in the growth hormone receptor gene previously published as having an association with protein composition and protein and milk yields. The association with protein composition was confirmed in this experiment, but not the association with protein and milk yields. A multiple SNP regression analysis for all SNP on chromosome 20 was performed for all 6 traits, which revealed that this mutation was not significantly associated with any of the milk production traits and that at least 2 other quantitative trait loci were present on chromosome 20.  相似文献   
99.
Khomchenko  V. S.  Kushnirenko  V. I.  Papusha  V. P.  Savin  A. K.  Lytvyn  O. S. 《Semiconductors》2010,44(5):685-690
ZnO-Ag thin films were prepared by a two-stage method on glass and sapphire substrates. Ag doping was carried out by a method of close space sublimation at atmospheric pressure. The film thickness is varied from 0.6 to 7 μm. The structural and radiative properties were explored by X-ray diffraction technique, atomic force microscopy, photoluminescence and cathodoluminescence spectroscopy. The influence of the fabricating conditions on the properties of ZnO-Ag films is studied. It is found that the Ag doping modifies the crystalline structure of the films and promotes the oriented growth of monocrystalline blocks with the size of 500–2000 nm in the [0002] direction. Improvement of the crystalline quality correlates with the change of the radiative characteristics of the films. The origin of emission centers is discussed.  相似文献   
100.
Addresses the problem of designing optimal stack filters by employing an L(p) norm of the error between the desired signal and the estimated one. It is shown that the L(p) norm can be expressed as a linear function of the decision errors at the binary levels of the filter. Thus, an L(p)-optimal stack filter can be determined as the solution of a linear program. The conventional design of using the mean absolute error (MAE), therefore, becomes a special ease of the general L(p) norm-based design developed here. Other special cases of the proposed approach, of particular interest in signal processing, are the problems of optimal mean square error (p=2) and minimax (p-->infinity) stack filtering. Since an Linfinity optimization is a combinatorial problem, with its complexity increasing faster than exponentially with the filter size, the proposed L(p ) norm approach to stack filter design offers an additional benefit of a sound mathematical framework to obtain a practical engineering approximation to the solution of the minimax optimization problem. The conventional MAE design of an important subclass of stack filters, the weighted order statistic filters, is also extended to the L(p) norm-based design. By considering a typical application of restoring images corrupted with impulsive noise, several design examples are presented, to illustrate the performance of the L(p)-optimal stack filters with different values of p. Simulation results show that the L(p)-optimal stack filters with p=/>2 provide a better performance in terms of their capability in removing impulsive noise, compared to that achieved by using the conventional minimum MAE stack filters.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号