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111.
Quaternization of trans-dipyridylporphyrin with 1,4-butaneditrifluoromethane-sulfonate affords new polyionenes containing porphyrin units in the
main chain. The polymers exhibit chemical and electrochemical reversible redox activities. Weitz-type two-step redox processes
similar to those of viologens account for the redox properties of the polymers.
Received: 26 November 1996/Revised: 24 January 1997/Accepted: 10 February 1997 相似文献
112.
Hideki Hyuga Mark I. Jones Kiyoshi Hirao Yukihiko Yamauchi 《Journal of the American Ceramic Society》2004,87(5):894-899
Si3 N4 /carbon fiber composites have been produced with and without seeding by an extrusion and sintering process. In both cases the carbon fibers were aligned along the direction of extrusion, but the Si3 N4 grains were only aligned in the seeded material. The mechanical properties of the specimens showed anisotropy with respect to the grain alignment, with both strength and toughness being highest in the direction parallel to the extruding direction. In this direction the seeded specimen, where both the Si3 N4 grains and the carbon fibers were aligned, showed both higher fracture toughness and higher fracture strength than the nonseeded specimen where only the fibers were aligned. 相似文献
113.
Takeshi Yanagisawa Takeshi Kojima Tadamasa Koyanagi Kiyoshi Takahisa Kuniomi Nakamura 《Microelectronics Reliability》2002,42(2):219-223
Changes in the characteristics of CuInGaSe2 solar cells in response to light irradiation were investigated. Then these changes, which suggest long-term degradation, were clarified using the measurement technique by feeble light. The thin-film cell of this type is considered to be “ever stable”. A stable result over the short term was also obtained in the light accelerated test of 2-SUN performed in this experiment. On the other hand, it was found that the characteristics measured with feeble light show a remarkable change over time. As a result of measuring at 0.065–105 mW/cm2 light intensity, the change rate of cell output power was so intense the measurement light was weak. This finding reflects the increase in an internal defect and suggests a possibility that light irradiation exerts the influence on long-term cell performance. Moreover, by measuring with feeble light, we found that the changed output recovers by reverse voltage application. The phenomenon of recovery up on comparatively low reverse voltage can be considered as an application for maintaining stability. 相似文献
114.
Hiroshi Kawanabe Kiyoshi Kawasaki Toshio Seno Chihiro Kondo Masahiro Shioji 《亚洲传热研究》2007,36(5):303-313
The flow and mixing process of unsteady jets are fundamentally analyzed by large eddy simulations. The effects of nozzle velocity and turbulence intensity on the turbulent eddy structure and mixing process between the nozzle fluid and ambient fluid were investigated. The results show that a toroidal‐shaped vortex, which emerges around the jet tip, primarily accelerates the entraining flow. Also, increasing the turbulence intensity in the nozzle encourages mixing in the jet without changing the jet‐contour. Furthermore, when the rise‐up time of the initial nozzle velocity is elongated, turbulent mixing is suppressed. © 2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(5): 303–313, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20158 相似文献
115.
Toshihiro Isobe Yoshikazu Kameshima Akira Nakajima Kiyoshi Okada Yuji Hotta 《Journal of Porous Materials》2006,13(3):269-273
The effect of additives on paste rheology was investigated for preparation of porous ceramics with unidirectionally aligned
cylindrical pores. Ammonium poly-carboxylic acid (APA) used as a dispersant and it was adsorbed on alumina powder surface.
The adsorption isotherm of APA was fitted by Langmuir equation. The saturated monolayer adsorption was 5.9 mg/g. The apparent
viscosity became a minimum at 0.8 mass % of APA corresponding to 71.2 mPa⋅s. This APA amount of 5.6 mg/g, is in good agreement
with the observed APA amount. Since the nylon 66 fibers (0–35 vol. %) mixed with the alumina powder have a strong interaction
with each other, they became twisted and agglomerated. This agglomeration increased with increasing fiber content but decreased
by adding oleic acid. The pastes with added oleic acid were capable of being extruded at higher pressure. The obtained porous
alumina ceramics showed highly oriented cylindrical pores parallel to the extrusion direction. The pore orientation was higher
in the oleic acid added pastes than those without oleic acid. The added nylon 66 fibers are mostly converted to pores while
maintaining the original shape after sintering. The pore size distribution of the obtained porous ceramics measured by mercury
porosimetry method showed a peak at about 4 μm which is apparently smaller than that observed in the SEM photographs and the
obtained result is considered to be corresponding to the necks formed by fiber contacts. 相似文献
116.
School of Engineering, Duke University, Durham, North Carolina, 27706. The status of wafer bonding technology especially for
silicon-on-insulator (SOI) materials is reviewed. General advantages of wafer bonding as well as specific problems of wafer
bonding, such as interface bubble formation, and solutions for these problems are discussed. The specific requirements for
SOI materials in terms of SOI layer thickness and the appropriate thinning procedures are dealt with. Interface properties
such as bonding strength and electrical properties are also reviewed. Various device results are mentioned. 相似文献
117.
Hisato Okuda Kazuhisa Katayama Xiaojun Wang Katsumi Masugata Kiyoshi Yatsui 《Electrical Engineering in Japan》1991,111(4):46-51
Experimental studies have been carried out on triggering characteristics of the SF6 discharge gap switch by use of XeCl excimer laser (wavelength = 308 nm). First, laser irradiation characteristics are studied on a pure SF6 in the pressure range of p = 160 ~ 3,800 torr. Using a lens of f (focal length) = 133 mm, the laser is irradiated into the gas, where the energy absorption is studied. If the laser is injected into the gas with the energy above a certain threshold for the breakdown, the rate of energy absorption is found to be ~ 17 percent of the incident energy at p > 760 torr. Injecting the laser into the SF6-filled gap switch (gap length = 7 mm, p = 760 torr), we have studied the triggering characteristics. Excellent triggering characteristics were obtained; delay time for the discharge ~ 20 ns, and the jitter ~ 260 ps when the gap voltage is operated at 99 percent of the self-breakdown voltage. In addition, the triggering characteristics are studied by changing the focusing point axially. It is found that both the delay time and the jitter decrease when the focusing point tends to approach the high-voltage electrodes. 相似文献
118.
Electrochemical properties of iron carbide (Fe3C) for use as an alkaline battery anode were investigated during charge–discharge cycles. Results of electrochemical measurements and Mössbauer spectroscopy suggested that Fe3C is oxidized irreversibly to Fe3O4 during discharge processes and that the produced Fe3O4 is subsequently changed to Fe(OH)2 and Fe during the charging process, raising the discharge/charge capacity in further galvanostatic cycles. In addition, the electrode particles were observed to be less than 100 nm in diameter and to be highly dispersed on the surface of carbon black. These phenomena seems to be caused by dissolution and deposition of Fe(OH)2 and Fe via intermediate iron species, leading to exposure of a fresh Fe3C surface to the electrolyte after the second discharge. 相似文献
119.
Akio Tanaka Kensuke Futahashi Kiyoshi Takanabe Chikara Kurimura Jungo Kato Hidekiyo Hara 《International Journal of Pressure Vessels and Piping》2008
A 3-D virtual analysis system to analyze the motion of control rod drive mechanism (CRDM) was developed. The analysis system consists of a 3-D model established as per the actual dimensions and interfaces of CRDM parts and a routine to calculate the forces acting on the mechanism, and was verified by mock-up test using the same equipment as the actual product. The analysis system is useful for functional evaluation in maintenance or to factor out root causes in the case of malfunction of CRDM. 相似文献
120.
Kiyoshi Kawaguchi Kenichi Okui Takahiro Shimoura Takaki Ohkouchi Hiroyuki Osakabe Tosihide Ninagawa 《亚洲传热研究》2007,36(4):230-247
In recent years, the requirement for the reduction of energy consumption has been increasing to solve the problems of global warming and the shortage of petroleum resources. A latent heat recovery type heat exchanger is one of the effective methods for improving thermal efficiency by recovering latent heat. This paper describes the heat transfer and pressure loss characteristics of a latent heat recovery type heat exchanger having straight fins (fin length: 65 mm or 100 mm, fin pitch: 2.5 mm or 4 mm). These were clarified by measuring the exchange heat quantity, the pressure loss of the heat exchanger, and the heat transfer coefficient between the outer fin surface and gas. The effects of fin length and fin pitch on heat transfer and pressure loss characteristics were clarified. Furthermore, equations for predicting the heat transfer coefficient and pressure loss which are necessary for heat exchanger design were proposed. ©2007 Wiley Periodicals, Inc. Heat Trans Asian Res, 36(4): 230– 247, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20153 Copyright © 2004 Wiley Periodicals, Inc. 相似文献