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排序方式: 共有1011条查询结果,搜索用时 15 毫秒
961.
Oleg Rybin Muhammad Raza Tahira Nawaz Tahir Abbas 《AEUE-International Journal of Electronics and Communications》2009,63(8):648-652
In this paper, analytical modeling and numerical simulation of the complex effective dielectric, magnetic constants and refractive index of a metallic rod metamaterial in microwave frequency range are presented. Analytical modeling has been done using modified mathematical models of the complex dielectric and magnetic constants obtained for rod metamaterial structure. Numerical simulation of the above-mentioned parameters has been made using S-parameters obtained with the help of finite-difference time-domain (FDTD) calculations. The numerical simulation has been carried out for different thickness of rods. Remarkable coincidence between analytical and numerical results was found. The effective dielectric constant enhancement of the considered composite has been obtained. Recommendations for the practical application of considered metamaterial structure for designing patch antennas have been discussed. 相似文献
962.
James Segala Donald M. Engelman Yana K. Reshetnyak Oleg A. Andreev 《International journal of molecular sciences》2009,10(8):3478-3487
The recurrence of certain cancers remains quite high due to either incomplete surgical removal of the primary tumor or the presence of small metastases that are invisible to the surgeon. Near infrared (NIR) fluorescence imaging might improve surgical outcomes by providing sensitive, specific, and real-time visualization of normal and diseased tissues if agents can be found that discriminate between normal and diseased tissue and define tumor margins. We have developed a new approach for revealing tumor borders by using NIR fluorescently labeled pH Low Insertion Peptide (pHLIP) and have created a computational program for the quantitative assessment of tumor boundaries. The approach is tested in vivo by co-localization of GFP-tumors and NIR emission from the fluorescently labeled pHLIP, and it is found that boundaries are accurately reported and that sub-millimeter masses can be detected. 相似文献
963.
Eungyeul Park Oleg Ostrovski Jianqiang Zhang Stuart Thomson Russell Howe 《Metallurgical and Materials Transactions B》2001,32(5):839-845
Iron carbide was prepared by iron ore reduction and iron cementation using Ar-H2-CH4 gas mixture with and without sulfur. Phases formed in the reduction/cementation process were examined by X-ray diffraction
(XRD), Mossbauer, and Raman spectroscopy. The sample surface was also analyzed by X-ray photoelectron spectroscopy (XPS).
XRD and Mossbauer analyses showed that iron oxide was first reduced to metallic iron, and then, metallic iron was carburized
to cementite. Addition of a small amount of H2S to the reaction gas retarded the cementite formation but made the cementite more stable. XPS analysis showed that the surface
of samples converted to iron carbide using sulfurcontaining gas consisted of mainly Fe3C and a small amount of graphitic carbon. Raman spectra of a sample produced in the iron carbide process showed the G and D bands, which are characteristic for carbon-carbon bonds. The intensity ratio of G/D bands depended on the sulfur content in the reducing/carburizing gas. 相似文献
964.
965.
In this paper, finite elements based on the absolute nodal coordinate formulation (ANCF) are studied. The formulation has
been developed by various authors for the dynamical simulation of large-displacement and large-rotation problems in flexible
multibody dynamics. This study introduces a procedure to track the general geometrical properties of ANCF elements back to
their prototypes in the conventional finite-element method (FEM), which deals with small-displacement problems. In this study,
it is shown that each known ANCF element can be derived from a conventional FEM using a universal transform. Moreover, some
important static and dynamic properties of the elements in small-displacement problems are automatically preserved. In the
past, the authors of each newly proposed ANCF element have made unnecessary efforts to show the consistency of the above mentioned
properties. 相似文献
966.
Irina Shiyanovskaya Seth Green Asad Khan Greg Magyar Oleg Pishnyak J. William Doane 《Journal of the Society for Information Display》2008,16(1):113-115
Abstract— This paper demonstrates the first substrate‐free cholesteric liquid‐crystal displays. The encapsulated cholesteric displays are ultra‐thin (with a total thickness around 20 μm) and ultra‐lightweight (0.002 g/cm2). The displays exhibit unprecedented conformability, flexibility, and drapability while maintaining electro‐optical performance and mechanical integrity. All functional display layers are sequentially coated on a preparation substrate and then lifted‐off from the preparation substrate to form a free‐standing display. The display fabrication process, electro‐optical performance, and display flexibility are discussed. 相似文献
967.
Thresholding algorithms, maxisets and well-concentrated bases 总被引:2,自引:1,他引:1
Gérard Kerkyacharian Dominique Picard Lucien Birgé Peter Hall Oleg Lepski Enno Mammen Alexandre Tsybakov G. Kerkyacharian D. Picard 《TEST》2000,9(2):283-344
The aim of this paper is to synthetically analyse the performances of thresholding and wavelet estimation methods. In this
connection, it is useful to describe the maximal sets where these methods attain a special rate of convergence. We relate
these “maxisets” to other problems naturally arising in the context of non parametric estimation, as approximation theory
or information reduction. A second part of the paper is devoted to isolate two very special properties especially shared by
wavelet bases, which allow them to behave almost as in an Hilbertian context even for L
p
risks. 相似文献
968.
Inna T Ermakova Natalya S Safrina Ivan I Starovoitov Yelena V Lyubun Alexander A Shcherbakov Oleg E Makarov Paul V Kosterin Alexander M Boronin 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2005,80(5):495-501
This work was undertaken to examine the possibility of biodegradation of the organic components of the ‘reaction masses’ (detoxification products) generated by destruction of the chemical warfare agent mustard. The composition of these components was analysed by gas chromatography and mass spectrometry. The major components formed during chemical detoxification were identified as 1,4‐perhydrothiazine derivatives. N‐(2‐Hydroxyethyl)‐2‐methyl‐1,4‐perhydrothiazine hydrochloride and N‐(2‐hydroxyethyl)‐3‐methyl‐1,4‐perhydrothiazine hydrochloride were predominant (about 70% of total 1,4‐perhydrothiazine derivatives). Pseudomonas putida strains that used some organic components of the mustard reaction masses as carbon sources for growth were isolated and selected. Growth cessation in this medium (with organic carbon still available) was due to the depletion of bioutilisable substrates, primarily monoethanolamine and ethylene glycol (the residual components of the detoxifying mixture). 1,4‐Perhydrothiazine derivatives were not used as carbon sources for growth of P putida strain SH1, but their concentration decreased during bacterial growth with monoethanolamine and ethylene glycol as the carbon substrates. It is suggested that 1,4‐perhydrothiazines undergo transformation by the microbial cells under these conditions. Copyright © 2005 Society of Chemical Industry 相似文献
969.
Nonisothermal Synthesis of Yttria-Stabilized Zirconia Nanopowder through Oxalate Processing: II, Morphology Manipulation 总被引:3,自引:1,他引:2
Oleg Vasylkiv Yoshio Sakka Hanna Borodians'ka 《Journal of the American Ceramic Society》2001,84(11):2484-2488
A novel, nontraditional route for controlling the morphology of yttria-stabilized zirconia nanopowders is explained. For understanding the real nature of yttrium zirconium oxalate nonisothermal decomposition and for the development of nanosize 3 mol% Y2 O3 ·97mol% ZrO2 , mass spectrometry, X-ray, and TEM investigation were used. Characteristics of zirconia crystallization under nonisothermal heating conditions were studied. Morphology evolution during Y-Zr oxalate nonisothermal decomposition was investigated to optimize the heating schedule of calcination. The nonlinear heating regime has been used to produce nanosized Y2 O3 -stabilized tetragonal ZrO2 powder with the finest primary crystallites and narrowest secondary aggregate size distribution. 相似文献
970.