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991.
Kiyoshi Kurahashi Yoshiji Matsuda Yoshitsugu Miyashita Tsuyoshi Demura Asakiyo Ueda Katsumi Yoshino 《Electrical Engineering in Japan》2006,155(3):1-8
Having a higher melting temperature than polyethylene, polypropylene has been expected to be an insulation material for power cables. But isotactic polypropylene (i‐PP) used generally is unsuitable as cable insulation because it shows poor flexibility, low breakdown strength due to growing spherulites, and so on. But stereoregular syndiotactic polypropylene (s‐PP) newly developed with metallocene catalyst shows quite different properties than i‐PP. In our previous paper, we investigated the basic properties of s‐PP and the initial properties as a cable which was manufactured using s‐PP insulation. It was revealed that s‐PP had superior thermal and electrical properties to cross‐linked polyethylene and the s‐PP insulation table showed satisfactory initial properties. However, in order to apply to an actual cable, the properties must be maintainable over 30 years after construction. In this paper, we estimated the long‐term remaining properties for s‐PP insulation table. A series of experiments on long‐term properties gave the following results: (1) s‐PP cable shows longer life over 30 years; (2) the breakdown strength of s‐PP cable after a long‐term experiment equal to 30 years is slightly lower than the initial breakdown strength, but it is sufficient as a remaining property. Furthermore, water‐tree resistivity of s‐PP was investigated and it was revealed that s‐PP significantly suppressed the water tree propagation compared with XLPE. These results suggested that s‐PP cable would serve as a next‐generation cable. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(3): 1–8, 2006; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20114 相似文献
992.
Reactive wetting of hexagonal BN by molten Al at 1073–1273 K was studied using an improved sessile drop method. The temperature
and substrate surface roughness have a remarkable effect on the wetting behavior. Reasons for the large discrepancy in the
final contact angles reported in the literature were addressed. 相似文献
993.
An approach to control‐oriented uncertainty modeling is presented for a class of elastic vibrating systems such as flexible structures, beams and strings, described by partial differential equations. Uncertainty bounding techniques are developed using the upper and lower bounds of the unknown eigenparameters. The result forms a basis for a finite‐dimensional controller design in which closed loop stability and performance are guaranteed. A feasible set of systems is defined of all systems governed by a class of differential equations with certain norm bounds of the unknown input and output operators and with partially known bounds of the eigenparameters. Then the perturbation magnitude covering the feasible set is evaluated in the frequency domain where a standard truncated modal model is chosen as the nominal one. An upper bound to the truncated error magnitude which is calculated by linear programming is proposed. It is demonstrated that all the parameters formulating a feasible set are derived by finite element analysis for a flexible beam example, and feasibility of the proposed scheme is also illustrated by numerical bounding results. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 155(2): 36–44, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20272 相似文献
994.
995.
Kiyoshi Kishioka 《Electrical Engineering in Japan》2005,150(3):1-10
This paper describes a simple method of analysis of an optical resonator composed of a nonlinear directional coupler. Assuming the coupler is made in semiconductor‐doped glass by the K+‐ion diffused technique, the transmission and reflection characteristics are calculated and demonstrated. The parameter dependence of the bistability appearing in the transmitted and reflected light is also presented. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(3): 1–10, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20036 相似文献
996.
Intergranular stress corrosion cracking behavior of niobium-added Type 308 stainless steel weld overlay metal in a simulated BWR environment 总被引:1,自引:0,他引:1
Type 308 stainless steel weld metal as an internal cladding of reactor pressure vessels for boiling water reactors is subject to postweld heat treatment during fabrication and can suffer sensitization depending on carbon and ferrite contents. This sensitization can be avoided by using niobium-added Type 308 weld metal (specified as Type 308 NbL) which was developed for one-layer overlay welding application. In the present study, stress corrosion cracking (SCC) behavior of heat-treated Types 308 and 308NbL weld metals in oxygenated high temperature pure water was evaluated by slow strain rate test and U-bend tests with and without crevice. Every test showed that Type 308NbL weld metals were highly resistant to SCC compared to ordinary Type 308 weld metals. In single U-bend test, one-layer overlay weld metals of Type 308NbL produced by electroslag welding process using wide strip electrodes were crack free over 23,000 h. The U-bend test data of ordinary Type 308 weld metals were successfully analyzed by an SCC reaction model. Using this analysis, the SCC life margin for Type 308NbL over ordinary Type 308 weld metals, expressed as a ratio of respective times to SCC initiation, was estimated to be about 36. 相似文献
997.
Hirotaka Komoda Masaaki Yoshida Yoh Yamamoto Kouji Iwasaki Ikuko Nakatani Heiji Watanabe Kiyoshi Yasutake 《Microelectronics Reliability》2006,46(12):2085-2095
FIB-induced charging is one of the most critical issues for achieving successful circuit modifications of LSI. We have developed novel charge neutralization techniques applicable to a wide current range (from pico to nanoampere-order) of FIB processing in a FIB-SEM combined system. The method utilizes a 500 eV focused electron beam instead of an electron shower, and also a combination of microprobing and FIB-assisted deposition to make a current path from FIB processing point to the grounded microprobe. The effects of our techniques on charge neutralization capability were investigated using electrically erasable-programmable read-only memory devices and n-MOS transistors. For the low FIB current condition of less than 500 pA, it is found that the focused electron beam prevents threshold voltage shifts of both irradiated and neighboring transistors, and that the ratio of electron to ion beam currents is a key parameter to achieving effective charge neutralization. We also demonstrated that the combined method of microprobing and FIB-assisted deposition prevents parameter shifts of transistors even for high-current (nanoampere-order) FIB irradiation. Moreover, we evaluated the upper-limit resistance of the current path formed by FIB-assisted carbon deposition to prevent charging induced by a given FIB current. 相似文献
998.
Yuji Fujitani Katsumi Saitoh Yoshinori Kondo Akihiro Fushimi Akinori Takami Kiyoshi Tanabe 《Aerosol science and technology》2016,50(10):1055-1067
The effective density ρeff of particles emitted from various types of automobile engines was measured using a differential mobility analyzer (DMA)–aerosol particle mass analyzer method, and their morphology was investigated via transmission electron microscopy analysis. The measured exhaust particles were particles emitted from diesel engines (DEs), gasoline direct injection spark ignition (DISI) engines, gasoline port fuel injection (PFI) engines, and liquefied petroleum gas (LPG) engines. ρeff and the morphology of the particles were measured after classification with the DMA, and six electrical mobility diameters Dm ranging from 30 to 300 nm were selected. ρeff was found to decrease as Dm increased for all particles. A morphological study showed that DE and DISI particles were mainly agglomerates and PFI and LPG particles were mainly nonagglomerates. Numbers and diameters of the primary particles in the agglomerates showed no systematic differences between DE and DISI particles at a given Dm. Rather, the primary particle diameter dp increased with increasing Dm of the agglomerates; the empirical relationship between the two diameters was found to be dp = 8.498ln(Dm) – 12.781 for DE and DISI particles. The core (elemental carbon) diameters in the primary particles of the DE particles increased as Dm increased and were estimated to range from 8.5 nm for Dm = 70 nm to 22.1 nm for Dm = 300 nm. Although the primary particle diameter and core diameter depend on Dm, the organic coating (shell) thickness, which ranged from 5.1 to 7.4 nm, was found to be independent of Dm.
Copyright © 2016 American Association for Aerosol Research 相似文献
999.
We observed a novel type of airflow produced by an atmospheric rf discharge between asymmetric parallel rod electrodes. The electrodes were a bare metal rod 1 mm in diameter and a glass-coated metal rod 3.2 mm in diameter. The thrust, measured by a pendulum, increased with discharge input power. 相似文献
1000.
Masashi Miyakawa Kiyoshi Kobayashi Takashi Taniguchi 《Journal of the American Ceramic Society》2017,100(4):1285-1289
Solid solutions of 12CaO·7Al2O3 (C12A7) and 12SrO·7Al2O3 (S12A7) crystals were synthesized under high pressure. X‐ray diffraction patterns revealed that the lattice constants of the synthesized samples depend linearly on the compositional ratio of C12A7 and S12A7. Electron‐probe X‐ray microanalyses show that the chemical compositions of the crystals are represented by xC12A7·(1?x)S12A7 (0<x<1). These results indicate that the variation in the lattice constants is originated from a difference in the ionic radii of Ca2+ and Sr2+ ions. From impedance measurements, it was found that S12A7 has the highest conductivity (~1 × 10?3 Scm?1 at 550°C) among the solid solutions in the C12A7–S12A7 system. 相似文献