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991.
The influence of the chemical structures of the polyamides on chlorine resistance was studied by measuring their chlorine uptake rates. They were prepared from isophthaloyl dichloride and aliphatic, cycloaliphatic, or aromatic diamines by the solution or interfacial polycondensation method. This study showed that the chlorine resistance was dependent on the chemical structures of the diamine compounds used in the synthesis of the polyamides. We concluded that the polyamides comprising the diamine components with the following chemical structures had higher chlorine resistance: aliphatic or cycloaliphatic diamine compounds with a secondary amino group, aliphatic or cycloaliphatic diamine compounds with a shorter methylene chain length between end amino groups, and aromatic diamine compounds with methyl or chlorine substituents at the ortho position of the amino groups. Chlorine resistance is related to the basicity of the aliphatic and aromatic diamines used. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 201–207, 2000 相似文献
992.
A molecular dynamics simulation has been performed for a two‐dimensional Lennard–Jones (12‐6) fluid. A saturated liquid at low temperature, compressed liquid, and fluid at supercritical temperatures with various densities were analyzed. Number of bonds per molecule, lifetime of bonds, connectivity of molecules to form clusters, stability of clusters, and their responses to temperature and density are compared with those of a hydrogen bond in water. © 2000 Scripta Technica, Heat Trans Asian Res, 29(3): 218–232, 2000 相似文献
993.
Takashi Yasuno Takuya Kamano Takayuki Suzuki Kazuo Uemura Hironobu Harada Yu Kataoka 《Electrical Engineering in Japan》2000,131(2):30-39
This paper introduces a human skill base control algorithm using artificial neural networks and fuzzy reasoning for an autonomous mobile robot. Neural networks are used to select a suitable motion control pattern in actual environments. The back propagation algorithm adjusts the weights of the neural networks so that the selected motion control pattern corresponds to the action, which is obtained by the operator's behavior decision skill. To realize the selected motion control pattern, the orientation angle and the speed of the mobile robot are determined by fuzzy reasoning in which fuzzy rules are also automatically tuned so as to simulate the operator's control skill. We have implemented and tested the proposed control algorithm on an autonomous mobile robot and some experimental results demonstrate the effectiveness of the proposed control algorithm for the autonomous mobile robot. © 2000 Scripta Technica, Electr Eng Jpn, 131(2): 30–39, 2000 相似文献
994.
995.
Hiromichi Watanabe Hideki Azuma Hiroyuki Nakano Takashi Sato Masashi Ohkawa Takeo Maruyama Minoru Shimba 《Electrical Engineering in Japan》1998,125(2):44-51
The frequency stability of a semiconductor laser deteriorated under direct frequency shift keying (FSK) when stabilization depended entirely upon an external frequency reference. Therefore, the PEAK method was devised for the purpose of improving frequency stability. This method requires two distinct frequency components and, therefore, will not work effectively in a communications system that produces a succession of identical frequencies, as does the FSK method on occasion. This paper, then, explains the results of our comparative analysis of the two modulation methods. The evaluation of frequency stability requires us to use a beat note between two stabilized laser beams, referred to here, as “signal” and “reference,” lasers. The reference laser is stabilized by a method that takes advantage of the magneto-optical effect. This laser restrains the tendency of the beat note frequency to broaden in other stabilization methods, and even makes it possible to predetermine the beat frequency to be employed. The improvement in frequency stability obtained is about one order of magnitude. © 1998 Scripta Technica, Electr Eng Jpn, 125(2): 44–51, 1998 相似文献
996.
Naoyuki Harada Katsuyoshi Toyoda Tsuneaki Minato Tadashi Ichihara Takuya Kishida Tatsuo Koike Toru Izumi Yoshishige Murakami 《Electrical Engineering in Japan》1997,121(3):44-52
An Nb3Sn superconducting magnet to store 400 kJ was developed as a unit magnet for a 2.4-MJ SMES system used for stabilization studies of electrical power systems. The superconducting magnet consists of a cryostat and an Nb3Sn coil. The dimensions of the coil are: 340 mm inner diameter, 700 mm outer diameter and 177 mm axial length. The pool-cooled coil is a stack of 20 Nb3Sn double pancakes, and the cooling channels are aligned between pancake coils. To reduce Joule loss in electrical power converters, the maximum operating current of the coil is designed to be 350 A, which is one order of magnitude less than the operating currents of similar scale coils for pulse use. The conductor is an Nb3Sn monolithic conductor with cross section 1.50 × 2.38 mm. For good superconducting stability and high dielectric strength of the coil, the Nb3Sn double pancakes were wound by the react-and-wind technique. Operation of dc current to 105% (367.5 A) of the design operating current was achieved without quench. After the whole of the coil was exposed out of liquid helium, the coil did not quench under 120 A current operation for more than 2 hours. It was verified that the coil was stable for the SMES system. © 1998 Scripta Technica, Inc. Electr Eng Jpn, 121(3): 44–52, 1997 相似文献
997.
Hiroyuki Nishikawa Eiki Watanabe Daisuke Ito Yoshimichi Ohki 《Electrical Engineering in Japan》1997,121(3):9-19
The formation mechanisms of paramagnetic defect centers in amorphous SiO2 induced by excimer lasers, 60Co γ rays, and mechanical fracturing were investigated. Correlation between the paramagnetic defect centers and their precursors introduced during manufacture is discussed for the cases of excimer lasers and γ rays. For the case of mechanical fracturing, formation of strained Si·O·Si bonds as well as paramagnetic defects is examined. The mechanism of laser- or γ-ray-induced paramagnetic defect centers is compared with that of fracture-induced centers. © 1998 Scripta Technica, Inc. Electr Erg Jpn, 121(3): 9–19, 1997 相似文献
998.
999.
Makoto Shimoyamada Kayoko Tmatsu Kenji Watanabe 《Journal of the science of food and agriculture》1999,79(2):253-256
Soymilk prepared from soybean seed was heated and frozen. After thawing, precipitation was shown to occur in soymilk. Precipitation from heated and frozen soymilk increased with increase in heating time. Precooling treatment (−5°C) before freeze‐storage of heated soymilk resulted in gel‐like solidification of soymilk. The gel strength of the freeze‐gel formed from soymilk was related to the heating time and the viscosity of the soymilk before freezing. © 1999 Society of Chemical Industry 相似文献
1000.
In recent years, attention has been paid to the concept of FACTS (Flexible AC Transmission Systems), along with significant progress in power electronic technology. A high‐speed phase shifter, which is one of the most promising devices in the FACTS concept, has the potential of power flow control and/or voltage stability in power transmission systems. In this paper, theory and experiment reveal that conventional high‐speed phase shifters may cause power swings in a transient state as a result of coupling between instantaneous active and reactive power control loops. Thus, two new control schemes for a high‐speed phase shifter are proposed to achieve both power flow control and power swing damping. The second proposed control scheme is based on the control scheme of an already proposed series active filter. Simulated and experimental results agree well with analytical results, not only in steady states but also in transient states. © 1999 Scripta Technica, Electr Eng Jpn, 128(2): 74–82, 1999 相似文献