全文获取类型
收费全文 | 105篇 |
免费 | 2篇 |
专业分类
化学工业 | 6篇 |
金属工艺 | 2篇 |
建筑科学 | 2篇 |
轻工业 | 1篇 |
石油天然气 | 2篇 |
无线电 | 19篇 |
一般工业技术 | 29篇 |
冶金工业 | 35篇 |
自动化技术 | 11篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 5篇 |
2011年 | 3篇 |
2010年 | 4篇 |
2009年 | 1篇 |
2008年 | 6篇 |
2007年 | 4篇 |
2006年 | 10篇 |
2004年 | 1篇 |
2003年 | 7篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 4篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有107条查询结果,搜索用时 0 毫秒
51.
A New Nonparametric Pairwise Clustering Algorithm Based on Iterative Estimation of Distance Profiles
Dubnov Shlomo El-Yaniv Ran Gdalyahu Yoram Schneidman Elad Tishby Naftali Yona Golan 《Machine Learning》2002,47(1):35-61
We present a novel pairwise clustering method. Given a proximity matrix of pairwise relations (i.e. pairwise similarity or dissimilarity estimates) between data points, our algorithm extracts the two most prominent clusters in the data set. The algorithm, which is completely nonparametric, iteratively employs a two-step transformation on the proximity matrix. The first step of the transformation represents each point by its relation to all other data points, and the second step re-estimates the pairwise distances using a statistically motivated proximity measure on these representations. Using this transformation, the algorithm iteratively partitions the data points, until it finally converges to two clusters. Although the algorithm is simple and intuitive, it generates a complex dynamics of the proximity matrices. Based on this bipartition procedure we devise a hierarchical clustering algorithm, which employs the basic bipartition algorithm in a straightforward divisive manner. The hierarchical clustering algorithm copes with the model validation problem using a general cross-validation approach, which may be combined with various hierarchical clustering methods.We further present an experimental study of this algorithm. We examine some of the algorithm's properties and performance on some synthetic and standard data sets. The experiments demonstrate the robustness of the algorithm and indicate that it generates a good clustering partition even when the data is noisy or corrupted. 相似文献
52.
53.
Arnon Golan 《Housing Studies》1998,13(4):487-505
Since the middle of the 19th century, housing the growing number of Jews immigrating to Palestine demanded resources that were not available to all immigrants. Housing projects were initiated either by Jewish philanthropists or building associations established by leaders of local communities. Numbers of immigrants rose sharply with the increasing involvement of the Zionist national movement in Palestine and the establishment of the British Mandatory regime. Most houses were built then by the private sector, widening the gap among different socio-economic groups. Only after the 1948 war and the termination of the colonial regime, was the newly established State of Israel able to initiate large-scale housing projects, due to its control of former Arabowned lands. The distribution of those lands raised conflicts between different sectors of the Israeli society, such as in the following two cases of public housing projects initiated in the Tel Aviv metropolitan area. 相似文献
54.
Y. Li Y. Golan A. Martin-Herranz O. Pelletier M. Yasa J. N. Israelachivili C. R. Safinya 《International Journal of Thermophysics》2001,22(4):1175-1184
The structure of a fluid membrane system composed of surfactant-co-surfactant-oil-water mixtures has been investigated under confinement and shear conditions. Small angle x-ray scattering (SAXS) was employed with a second generation x-ray surface forces apparatus (XSFA-II) to study the time evolution of the orientational structure of the lamellar fluid under oscillatory shear. In a regime of relatively big confinement gap (800 m) and small shear amplitude (40 m), direct evidence of an orientational phase separation behavior, where a surface boundary layer adopts different orientation and separates from the bulk region, was observed for the first time. Under continuous shearing, the surface boundary layer grows in thickness and aligns towards a shear-favored (low friction) state while the bulk orientation remains unchanged. To further investigate the effects of surface confinement, we spatially mapped, in 1 m sections, the orientation structure of the lamellar fluid sample confined between two glass surfaces using a micro-focused x-ray beam produced by a linear Bragg–Fresnel lens at the Advanced Photon Source. The data confirmed the expected trend that the smectic domains align progressively better with respect to the surface as they approach the surface. 相似文献
55.
In this paper, an improved design of a tunable optical filter device which is driven by a piezoelectric actuator is proposed. The device can be used either as a tunable optical filter for discrete wavelength alignment or as a dynamic optical filter. The tunable filter is electrostatically driven and consists of three main parts: The electromechanical stage, the suspension and the thin film optical filter. The electromechanical stage and the suspension were designed using graph presentation methods, studied numerically using the finite element method (FEM). The thin film optical filter was designed by a thin film design software. The electromechanical stage was integrated with the suspension and tested as an angular driver of thin-film tilt interference filter for dense-wavelength division demultiplexing system applications. 相似文献
56.
57.
Vanadium oxide VO2 is a material that transforms from semiconductor to a metal state at a temperature of 67 °C. This phase transformation is accompanied by a dramatic change in its electrical and optical properties. Therefore, vanadium oxide thin films are most attractive for switching applications. Non-stoichiometric thin films of VOx, including VO2, also present such thermal response.This paper presents the optical and electrical properties of vanadium oxide thin films deposited by vacuum thermal evaporation of a metal vanadium with follows oxidation. We have studied the electro-physical behavior of these films during their phase transition. It was shown that the electrical transport mechanism of the obtained vanadium oxide films differ in low and high electrical fields. In low electrical fields, conductivity is obtained by the Schottky transport mechanism, whereas in high electrical fields, conductivity ranges from Ohmic, for medium fields, to Poole-Frenkel for higher fields. Also, FTIR and near IR reflectance characteristics of the obtained films are presented. 相似文献
58.
A Treister O Sagi-Assif M Meer NI Smorodinsky R Anavi I Golan T Meshel O Kahana R Eshel BZ Katz E Shevach IP Witz 《Canadian Metallurgical Quarterly》1998,77(2):306-313
Bradykinin-induced responses were studied in isolated porcine iliac arteries. Relaxation was endothelium dependent and seen at low concentrations (10(-10)-10(-8) M) of bradykinin. It was inhibited by the bradykinin B2-receptor antagonist icatibant (HOE-140) and by the nitric oxide synthase inhibitor Nomega-nitro-L-arginine. Bradykinin-induced relaxation was significantly potentiated by the kininase I carboxypeptidase inhibitor mergepta (10(-6) M). Bradykinin (>10(-7) M) elicited contraction of preparations with or without endothelium. The contraction was abolished by indomethacin but was not affected by the thromboxane A2/prostaglandin H2-receptor antagonist SQ 29,548. Icatibant and the bradykinin B1-receptor antagonist desArg9[Leu8]bradykinin significantly decreased bradykinin-induced contraction regardless of endothelial function. The contraction also was decreased by treatment with mergepta. The bradykinin B1-receptor agonist desArg9-bradykinin contracted endothelium-denuded arterial strips. This contraction was significantly decreased by desArg9[Leu8]bradykinin but not by icatibant. The desArg9-bradykinin-induced contraction also was inhibited by the protein-synthesis inhibitor cycloheximide. Neither bradykinin-induced relaxation nor contraction was affected by the ACE inhibitors enalaprilat or cilazaprilat. In conclusion, bradykinin-induced relaxation of isolated porcine iliac arteries was mediated by endothelial bradykinin B2 receptors and mainly nitric oxide. Bradykinin-induced contraction was endothelium independent, indomethacin sensitive, and probably mediated by bradykinin B1 (inducible) and B2 receptors located in the vascular smooth-muscle layer. Kininase I carboxypeptidase, and not ACE, is the main enzyme responsible for bradykinin degradation in these vessels. 相似文献
59.
GA Holl?nder S Zuklys C Morel E Mizoguchi K Mobisson S Simpson C Terhorst W Wishart DE Golan AK Bhan SJ Burakoff 《Canadian Metallurgical Quarterly》1998,279(5359):2118-2121
The lymphokine interleukin-2 (IL-2) is responsible for autocrine cell cycle progression and regulation of immune responses. Uncontrolled secretion of IL-2 results in adverse reactions ranging from anergy, to aberrant T cell activation, to autoimmunity. With the use of fluorescent in situ hybridization and single-cell polymerase chain reaction in cells with different IL-2 alleles, IL-2 expression in mature thymocytes and T cells was found to be tightly controlled by monoallelic expression. Because IL-2 is encoded at a nonimprinted autosomal locus, this result represents an unusual regulatory mode for controlling the precise expression of a single gene. 相似文献
60.
B Avidor Y Kletter S Abulafia Y Golan M Ephros M Giladi 《Canadian Metallurgical Quarterly》1997,35(8):1924-1930
Amplification of Bartonella henselae DNA has been proposed as a diagnostic test for cat scratch disease (CSD). The sensitivities of the following three PCR assays were compared. PCR/rRNA with universal primers amplifies part of the 16S rRNA gene, followed by hybridization with a specific B. henselae probe; PCR/CS and PCR/HSP amplify portions of the gltA and the htrA genes, respectively, each followed by restriction fragment length polymorphism analysis. The threshold of detection of B. henselae DNA in pus was 10(-4), 10(-3), and 10(-2) ng for PCR/rRNA, PCR/CS, and PCR/HSP, respectively. By these three assays, B. henselae DNA was detected in 100, 94, and 69% of 32 pus and lymph node specimens from CSD patients, respectively. The similar sensitivities of the PCR/rRNA and the PCR/CS assays for detecting B. henselae DNA in clinical specimens are in contrast to the 10-fold difference in sensitivities in favor of PCR/rRNA demonstrated with purified B. henselae DNA in sterile pus, suggesting that in the majority of cases, the bacterial load in clinical specimens is large enough to be identified by the PCR/CS assay. A two-step approach is suggested to achieve maximal sensitivity for detecting B. henselae in clinical specimens: initial testing by PCR/CS (which does not require hybridization), followed by PCR/rRNA with PCR/CS-negative specimens when CSD is strongly suspected. 相似文献