全文获取类型
收费全文 | 181篇 |
免费 | 7篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 33篇 |
机械仪表 | 4篇 |
建筑科学 | 5篇 |
能源动力 | 4篇 |
轻工业 | 10篇 |
无线电 | 18篇 |
一般工业技术 | 19篇 |
冶金工业 | 61篇 |
自动化技术 | 29篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 8篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 13篇 |
2012年 | 7篇 |
2011年 | 6篇 |
2010年 | 2篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 3篇 |
2004年 | 2篇 |
2003年 | 3篇 |
2002年 | 2篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 4篇 |
1998年 | 16篇 |
1997年 | 19篇 |
1996年 | 18篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有188条查询结果,搜索用时 15 毫秒
41.
CE Neumaier F Onetto S Delucchi G Cittadini E Silvestri 《Canadian Metallurgical Quarterly》1997,52(4):310-311
Neurofibrosarcomas are rare neoplasms usually associated with von Recklinghausen's disease. In this paper we describe ultrasound (US), computed tomography (CT) and magnetic resonance (MR) appearances of an unusual isolated neurofibrosarcoma of the liver. 相似文献
42.
P. Russo A. Costantini G. Luciani F. Tescione M. Lavorgna F. Branda B. Silvestri 《应用聚合物科学杂志》2018,135(11)
In this work, experimental results about poly(butylene terephthalate) (PBT) based nanocomposites filled with various amounts of silica nanoparticles (NPs) are reported. Two different types of filler are used: silica gel NPs, produced through the Stöber method, and a commercial fumed silica, both coated by a PBT shell. Melt‐mixed samples have been thoroughly investigated by scanning and transmission electron microscopy, infrared Fourier transform spectroscopy (FTIR), thermal gravimetric analysis, differential scanning calorimetry, wide and small angle X‐ray diffraction, and dynamic mechanical analysis. A fine and very good dispersion of NPs into the polymeric matrix is revealed through the morphological analysis when Stöber NPs were used as filler with respect to systems including commercial fumed silica particles. This evidence, combined with matrix–filler interactions revealed by FTIR spectroscopy, justifies the enhancement of both storage modulus and glass transition temperature of the former samples in comparison with reference pristine PBT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46006. 相似文献
43.
Sheinwald, Lempel, and Ziv (1995,Inform. and Comput.116, 128–133) proved that the power of off-line coding is not useful if we want on-line decodable files, as far as asymptotical results are concerned. In this paper, we are concerned with the finite case and consider the notion of on-line decodable optimal parsing based on the parsing defined by the Ziv–Lempel (LZ2) compression algorithm. De Agostino and Storer (1996,Inform. Process. Lett.59, 169–174) proved the NP-completeness of computing the optimal parsing and that a sublogarithmic factor approximation algorithm cannot be realized on-line. We show that the Ziv–Lempel algorithm and two widely used practical implementations produce an O(n1/4) approximation of the optimal parsing, wherenis the length of the string. By working with de Bruijn sequences, we show also infinite families of binary strings on which the approximation factor isΘ(n1/4). 相似文献
44.
This article presents a novel band‐pass filter topology, based on the half‐mode substrate integrated waveguide (HMSIW), which allows for the simple design and easy manufacturing of filters with different bandwidth and number of poles. The design strategy, based on the modification of HMSIW cavity modes, is discussed in the case of two‐pole and four‐pole filters, and two prototypes are implemented and experimentally verified. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:72–79, 2016. 相似文献
45.
The electrochemical carboxylation of acenaphthylene totrans-acenaphthene-1,2-dicarboxylic acid and acenaphthene-1-carboxylic acid has been investigated. The yields of the synthesis are influenced by the cathode material by the current density and, in the case of acenaphthene-1-carboxylic acid, by the pressure of carbon dioxide. In preparative experiments, performed in a gas lift electrochemical cell, up to 100 g oftrans-acenaphthene-1,2-dicarboxylic acid were obtained at cathodic current densities of 40 mA cm–2 and with current yields greater than or equal to 80%. 相似文献
46.
Alessandro Pezzella Luigia Capelli Aniello Costantini Giuseppina Luciani Fabiana Tescione Brigida Silvestri Giuseppe Vitiello Francesco Branda 《Materials science & engineering. C, Materials for biological applications》2013,33(1):347-355
A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds.Here we report the use of the approach referred as “chimie douce”, involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO2. Two synthesis procedures were carried out to get DHICA-melanin coated TiO2 nanoparticles as well as mixed DHICA/TiO2 hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO2 nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10 nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO2 hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt. 相似文献
47.
48.
Abstract: During usual data gathering, the statistical analysis efficiency strongly depends on the noise level superimposed on the signal. It has been found that some well known statistical tests, commonly utilised in data acquisition in order to detect the presence of drift, can fail under some conditions. Thus, a statistical procedure for the predictive reliability estimation of the utilised statistical method could be useful in the design of experimental analysis. This paper reports the results of a simulation study carried out to evaluate the performance in drift detection of non-parametric tests such as the Wald-Wolfowitz run test, in comparison with the Mann-Whitney, reverse arrangement test. In order to detect the sensitivity of the tests to evaluate a monotonous drift, a simulation program was developed. In the program a Gaussian raw data sequence with a linear pattern of variable slope and with variable variance was simulated and given as the input to the tests. The capability to detect the presence of drift as a function of angular coefficient and variance of the noise superimposed on the signal was verified. The obtained data were synthesised in graphs so that the experimentalist could determine preliminarily the effectiveness of each of the considered statistical methods in terms of percentage of success in detecting the presence of drift phenomena as a function of drift relevance and the noise amplitude. Finally, the graphs permitted the elucidation of the causes of contradictory failing results observed in long term experimental analysis. 相似文献
49.
Antonio Forcina Luca Silvestri Gianpaolo Di Bona Alessandro Silvestri 《Quality and Reliability Engineering International》2020,36(6):2085-2107
The choice of a reliability allocation method is not always easy or straightforward, since it depends on several factors. Some factors are directly related to the characteristics of the analyzed system, such as the level of complexity or the reliability configuration; on the other hand, additional aspects constitute boundary conditions, such as budget or experimentation time. In this scenario, the purpose of the present research is to present a systematic literature review on reliability allocation, proposing a guideline to choose the optimal allocation method in respect to the desired application, available resources, and required accuracy. The proposed review analyzes allocation methods in literature, determining main features and area of application. Motivated by a lack of a comprehensive methods summarization present in literature, our research goal is to assist practitioners in choosing a well-suited method and to provide an overview, to support academics in conducting new research in this area. The results of the performed analysis are synthetized according to several criteria. The results are summarized and categorized in different clusters for each individuated application field. The proposed summarization design allows an easy and rapid consultation. 相似文献
50.
The questions of how and why individuals develop normal or abnormal interpersonal patterns have received nonconsistent answers in the behavioral sciences, perhaps because they were too much concerned with the semantics and the syntax aspects of the communication process that mediates human interaction. This paper demonstrates that a pragmatic approach is necessary and sufficient to answer the above questions. The information processing aspect of the “single bit of information exchange” model (P. De Giacomo and A. Silvestri, 1979) is developed to create a computer simulation procedure. Using both clinical data and normal population measurements of KALTEST (O. G. Pereira and C. P. Ferreira, 1984) as the basic criteria, it is found that the development of a stable normal pattern of interaction depends on the ability to share proposals with the other significant person in the environment and that the development of an abnormal pattern depends on refusal to share coupled with a tendency to escape from the ring of the interaction. 相似文献