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91.
Mari Pau Balaguer Joaquin Gomez-EstacaJosep Pasqual Cerisuelo Rafael GavaraPilar Hernandez-Munoz 《LWT》2014
In this work a new methodology based on thermo-pressing a resin made from gliadins and glycerol has been developed to obtain water resistant films. The effect of processing temperature was studied on the functional properties of the films. The results of SDS-PAGE analysis of the molecular weight profiles of the resulting films were indicative of disulfide/sulfhydryl interchange reactions giving rise to the formation of intermolecular disulfide bonds between the gliadin units. These reactions augmented the degree of cross-linking of the matrix, which increased with thermo-pressing temperature, as evidenced by the residual reaction enthalpy values determined by MDSC as well as by cross-linking density values determined from tensile tests. In consequence the films produced at high temperature had better water resistance upon immersion, greater maximum tensile strength and Young's modulus values, and lower water vapor and oxygen permeabilities compared with cast films. Based on the analytical test results, thermo-pressing the resin in successive time/force steps along with a temperature of 130 °C produced gliadin films with improved properties. 相似文献
92.
Catalin Popa Yuki Okayasu Ken-ichi Katsumata Toshihiro Isobe Nobuhiro Matsushita Akira Nakajima Taisuke Kurata Kiyoshi Okada 《Journal of Materials Science》2013,48(2):941-947
Porous mullite ceramics with unidirectionally oriented pores were prepared by an extrusion method using rayon fibers as the pore formers. Rayon fibers of 8.1, 9.6, 16.8, and 37.6 μm in diameter were used as the pore formers and were kneaded with alumina powder, kaolin clay, China earthen clay, and water to form pastes. These pastes were extruded into cylindrical tubes, dried, and fired at 1500 °C for 4 h. The apparent porosities ranged from 45.7 to 48.2 %. The pore size distributions showed a sharp peak at 9.4, 10.0, 15.6, and 30 μm with increasing fiber diameters. The height of the capillary rise was 1780, 1670, 1320, and 950 mm with increasing fiber diameter. The maximum capillary rise is much higher than previously reported. The contact angle and effective pore radius that determine the capillary rise ability were calculated by fitting the capillary rise curves using the Fries and Dreyer’s equation. 相似文献
93.
This paper investigates, theoretically and experimentally, the applicability of the Space-Time Enlargement Law to vacuum-insulated systems. A discussion on how characteristics of possible vacuum breakdown mechanisms determine the distribution function of the breakdown voltage random variable is presented. By superimposing effects of electrode surface enlargement and inter-electrode gap enlargement, expressions for the mean value and standard deviation of the breakdown voltage random variable are obtained. In the case of time extensions, the assumption of complete independence of consecutive discharge processes is discussed. Experimental testing of the Enlargement Law was performed on Rogowski type two-electrode systems, with different electrode surface areas, inter-electrode gaps and vacuum pressures. Measurements were conducted using industrial ac voltage, dc voltage with 50 V/s rate of rise, standard atmospheric pulse voltage (1,2/50 μs), and commutational pulse voltage (250/2500 μs). The final conclusion, based on the comparison of theoretical considerations and the experimental results, is that the Space-Time Enlargement Law can be applied in the design phase during the development of vacuum devices, with certain limitations, regardless of the type of the applied voltage. 相似文献
94.
We describe a technique, simpler than earlier ones, for using SPICE in the computation of the 1/f, step, and delta noise indices of linear and time-valiant filters. The method is based on obtaining a weighting function from the results of simulation and is demonstrated for triangular and trapezoidal shapers. The results are compared with those obtained by direct calculation. The greatest discrepancies occur when the method is applied to gated integrators, but the errors are probably due to artifacts not related to the basic method described here 相似文献
95.
Mari K. N?ss David J. Young Jianqiang Zhang Jan Erik Olsen Gabriella Tranell 《Oxidation of Metals》2012,78(5-6):363-376
Small scale laboratory experiments on the oxidation of liquid silicon have reproduced important features of the industrial refining of liquid silicon: active oxidation led to the formation of amorphous silica spheres as a reaction product. The boundary condition for active oxidation in terms of maximum oxygen partial pressure in the bulk gas was found to lie between 2·10?3 and 5·10?3?atm at T?=?1,500?°C. The active oxidation of liquid silicon had linear kinetics, and the rate was proportional to bulk oxygen partial pressure and the square root of the linear gas flow rate, consistent with viscous flow mass transfer theory. Classical theory for unconstrained flow over a flat plate led to mass transfer rates for SiO(g) which were 2–3 times slower than observed. However, computational fluid dynamic modeling to take into account the effects of reactor tube walls on flow patterns yielded satisfactory agreement with measured volatilization rates. 相似文献
96.
Multi-objective Coverage-based ACO Model for Quality Monitoring in Large Water Networks 总被引:2,自引:2,他引:0
A numerical procedure is presented for the optimization of the position of water quality monitoring stations in a pressurized
water distribution system (WDS). The procedure is based on the choice of the set of sampling stations which maximizes the
monitored volume of water while keeping the number of stations at minimum. The optimization model is formulated in terms of
integer programming, and the solution of the mathematical problem is efficiently approximated by means of a multi-objective
multi-colony ant algorithm. A built-in routine is developed for calculation of the water fraction matrix and integrated into
the general modeling structure to facilitate data entry and storage to minimize problems associated with water fraction matrix
determination for varying scenarios and coverage criteria for any scenario. The proposed methodology is very robust in analyzing
the effects of different scenarios and/or number of potential monitoring stations by eliminating the need of employing an
off-line routine for coverage matrix identification. Robustness, ease of generalization, multi-objective nature, and computational
efficiency are the main characteristics and novelty of the proposed approach. Monitoring stations are optimally located in
a large-scale real-world network with 104 nodes and multiple demands using the proposed ACO models. The set of non-dominated
solutions forming the Pareto front for a number of monitoring stations and the total coverage of the system are also presented. 相似文献
97.
Daiki Honma Motoyuki Tagashira Tomomasa Kanda Mari Maeda‐Yamamoto 《Journal of the science of food and agriculture》2010,90(1):168-174
BACKGROUND: Tea (Camellia sinensis L.) is consumed all over the world and in especially large quantities in Japan and China, where it has been used not only as a daily beverage but also for medicinal purposes for thousands of years. Tea has been found to exhibit various bioregulatory activities, including antiallergic, anticarcinogenic, antimetastatic, antioxidative, antihypertensive, antihypercholesterolemic, anti‐dental caries and antibacterial effects, and to influence intestinal flora. RESULTS: Cha Chuukanbohon Nou 6 is a tea cultivar improved by the National Institute of Vegetable and Tea Science (NIVTS) in Japan. On comparing chemical constituents of 11 varieties of tea leaves by high‐performance liquid chromatography, we found two new major compounds in Cha Chuukanbohon Nou 6. Nuclear magnetic resonance spectroscopy revealed these compounds to be theogallin and 1,2‐di‐O‐galloyl‐4,6‐O‐(S)‐hexahydroxydiphenoyl‐β‐D ‐glucopyranose. The two were similar in chemical structure to strictinin, an inhibitor of immunoglobulin (Ig) production. Thus their effects on the production of Igs by peripheral blood lymphocytes were tested. Both compounds, like strictinin, inhibited IgE production. CONCLUSION: The results suggest Cha Chuukanbohon Nou 6 to be the basis of an antiallergic beverage. Copyright © 2009 Society of Chemical Industry 相似文献
98.
Impact of social comparisons on the developing self-perceptions of learning disabled students. 总被引:1,自引:0,他引:1
Learning disabled (LD) children's self-perceptions were investigated using the Perceived Competence Scale for Children. This self-report instrument taps children's perceptions of their scholastic and athletic competence, social acceptance, and feelings of global self-worth. Participants in the study were 86 students in Grades 3–8 who attended a public school LD resource room. Results indicated that social comparison processes play an important role in the formation of LD students' perceived academic competence. LD students perceived themselves as becoming less academically competent across the grade span tested when they compared themselves with normally achieving students in their regular classes. When they compared their abilities with LD peers in their resource room, they maintained high perceptions of their own academic competence. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
99.
Mari?l Droomers; Schrijvers Carola T. M.; Mackenbach Johan P. 《Canadian Metallurgical Quarterly》2002,21(3):263
This article describes the effect of educational level on the decision to continue smoking among 1,354 initially smoking participants (age≥20 years) in the Dutch GLOBE study. The effect of education continued smoking was explained from baseline information (1991) on smoking characteristics, individual characteristics, and environmental factors. Smoking status was reassessed after 6.5 years. Lower educated smokers more often continued smoking (odds ratio 2.09). Poor perceived health and earlier smoking initiation in lower educated groups were main predictors of educational differences in smoking maintenance. Educational differences in chronic illness, perceived control, neuroticism, and emotional support also contributed to the explanation of educational differences in continued smoking. These results have important implications for intervention programs and policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
100.
Shingo Hasegawa Shuji Isobe Hiroki Shizuya Katsuhiro Tashiro 《International Journal of Information Security》2009,8(5):347-355
The notion of pseudo-free group was first introduced by Hohenberger (Master’s thesis, EECS Dept., MIT, 2003). Rivest (TCC
2004. LNCS 2951, 505–521, 2004) formalized it and showed that several standard cryptographic assumptions hold on pseudo-free groups, such
as the RSA assumption, the strong RSA assumption and the discrete logarithm assumption. Rivest (TCC 2004. LNCS 2951, 505–521, 2004) also proposed some variations of pseudo-free group, and those were formalized by Hirano and Tanaka (Research
Reports, Series C: Computer Science, C-239, Tokyo Institute of Technology, 2007). In this paper, we study the relationships
among such variations of pseudo-free group. We show that the pseudo-freeness implies the weak pseudo-freeness, and that the
pseudo-freeness is equivalent to the pseudo-freeness with generalized exponential expressions. We also show that the computational
Diffie-Hellman assumption holds on pseudo-free groups in a slightly varied form. 相似文献