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51.
We present a new signal processing and testing technique by using a higher statistical moment, the bispectrum, to determine the damping ratio and natural frequency of offshore structures excited by both unexpected Gaussian forces and known non-Gaussian driving forces. Due to unexpected exciting forces, such as turbulence, in the ocean, environment, the transfer functions of offshore structures are not determined through operating a known driving force and measuring its response. In order to overcome this problem, some of the existing techniques try to model the unexpected forces as white Gaussian forces or almost white Gaussian forces and determine the modal parameters from the response only. Others try to average the input and output to suppress unexpected parts. Our method uses third-order moments to keep the influence of the unexpected Gaussian forces away from the determination of the transfer function of the structure which has linear properties. We model the third-order moment property of the response function with a bispectral model. The modal parameters can be calculated from the estimated model's coefficients. The method has been proven by a number of simulations. 相似文献
52.
BACKGROUND: Tacrolimus (FK506) may represent a major advance in the management of allograft rejection after solid organ transplantation. In August 1994 a European heart transplantation pilot study was initiated to assess the efficacy and safety of tacrolimus when administered exclusively through an oral route. METHODS: Eighty-two heart transplant recipients were randomized to treatment (2:1 ratio) with either tacrolimus- (n=54) or cyclosporine-based therapy (n=28). RESULTS: No significant differences were evident between the two treatment groups in either rejection or survival rates at 1 year. Kaplan-Meier estimates of the freedom from rejection were 26.3% and 18.5%, respectively, for the tacrolimus and cyclosporine treatment groups (p=.444). Survival rates were 79.6% and 92.9% (p=.125). At 3 of the 5 centers, patients received antithymocyte globulin during the immediate postoperative period and fared better than those who did not (with acute rejection-free rates of 49.2% and 26.7% for tacrolimus and cyclosporine, respectively [p=.080], as opposed to 7.1% and 8.3% [p=.965]; patient survival rates of 84.6% and 93.3% [p=.382] vs 75.0% and 92.3% [p=.243]). The overall rates of infection, impaired renal function (31.5% vs 21.4%), and glucose intolerance (7.0% vs 4.3%) did not differ significantly between the tacrolimus and cyclosporine treatment groups. Tacrolimus seemed to possess an advantage with regard to a reduced requirement for antihypertensive therapy (59.5% vs 87.5%, p=.025). CONCLUSIONS: Immunosuppression with oral tacrolimus provides a viable alternative to treatment with cyclosporine, particularly when administered in conjunction with antibody therapy. Further studies are warranted to optimize the administration of tacrolimus in this indication. 相似文献
53.
Two different schemes, i.e. adaptive and nonadaptive systems, are developed for intrafield transform (2d-DCT) image processing of a digital NTSC color composite video signal, sampled at three times the color subcarrier frequency. The fast transform algorithm for 2d-DCT (8 × 8 subblock) is used. Based on the statistics of the transform coefficients, variable word length quantizers, optimized for minimizing the mean square error, are developed. These techniques lead to reduced bit rates for transmitting color video at broadcast standards. The performance of adaptive system is much better than that of nonadaptive system. Although the necessary hardware will likely exceed what is needed for a nonadaptive system, the benefits will more than offset the hardware complexity. The effect of channel noise in the adaptive system is investigated in terms of severity and propagation patterns. This is carried out by using a forced error scheme which selectively forces the error to occur in the different types of coding bits. Error propagation patterns are studied by series of computer printouts. 相似文献
54.
An approach is presented to estimate the surface aerosol radiative forcing by use of collocated cloud-screened narrowband spectral and thermal-offset-corrected radiometric observations during the Puerto Rico Dust Experiment 2000, South African Fire Atmosphere Research Initiative (SAFARI) 2000, and Aerosol Characterization Experiment-Asia 2001. We show that aerosol optical depths from the Multiple-Filter Rotating Shadowband Radiometer data match closely with those from the Cimel sunphotometer data for two SAFARI-2000 dates. The observed aerosol radiative forcings were interpreted on the basis of results from the Fu-Liou radiative transfer model, and, in some cases, cross checked with satellite-derived forcing parameters. Values of the aerosol radiative forcing and forcing efficiency, which quantifies the sensitivity of the surface fluxes to the aerosol optical depth, were generated on the basis of a differential technique for all three campaigns, and their scientific significance is discussed. 相似文献
55.
Yi‐Bing Lin Ren‐Huang Liou Yuan‐Kai Chen Zheng‐Han Wu 《Wireless Communications and Mobile Computing》2013,13(12):1111-1119
Call forwarding is a traditional telecom service that allows a user to forward incoming calls to another telephone number. This service requires the user to manually activate and deactivate the feature and therefore may not be very convenient. This paper proposes an automatic call‐forwarding algorithm (CFA) for mobile phones. By installing a software in a smartphone, call forwarding is automatically triggered (e.g., when the phone is plugged in a charger or is turned off) or disabled (e.g., when the phone is unplugged from the charger or is turned on). We investigate the performance of the CFA through analytic analysis, simulation, and measurement. Our study indicates that CFA is very feasible for commercial usage. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
56.
Dr. Hsueh‐Yun Lee Dr. Chia‐Ron Yang Dr. Mei‐Jung Lai Han‐Li Huang Yi‐Ling Hsieh Yi‐Min Liu Dr. Teng‐Kuang Yeh Yu‐Hsuan Li Samir Mehndiratta Dr. Che‐Ming Teng Dr. Jing‐Ping Liou 《Chembiochem : a European journal of chemical biology》2013,14(10):1248-1254
A series of 1‐arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines ( 7 – 15 ) has been developed; the compounds exhibited potent histone deacetylase (HDAC) inhibitory activities. Notably, almost all of this series exhibited better HDAC‐inhibitory and antiproliferative activities than 3‐(1‐benzenesulfonyl‐1H‐indol‐5‐yl)‐N‐hydroxyacrylamide ( 6 ), as reported in a previous study. Among these compounds, 3‐[1‐(4‐methoxybenzenesulfonyl)‐2,3‐dihydro‐1H‐indol‐5‐yl]‐N‐hydroxyacrylamide ( 9 ) showed a two‐ to tenfold increase in activity compared to SAHA ( 1 ) in the suppression of lipopolysaccharide‐induced cytokine production. Compound 9 also caused a marked reduction in carrageenan‐induced acute inflammation in a rat model. Taken together, these data indicated that 1‐arylsulfonyl‐5‐(N‐hydroxyacrylamide)indolines HDAC inhibitors exhibit potent anti‐inflammatory activity. 相似文献
57.
James J.H. Liou Jolanta Tamošaitienė Edmundas K. Zavadskas Gwo-Hshiung Tzeng 《国际生产研究杂志》2016,54(1):114-134
Greening the supply chain is an increasingly important concern for many business enterprises and a challenge for logistics management. Critical functions within green supply chain management are internal improvements and selection of green suppliers. This study proposes a novel, hybrid model that addresses dependent relationships between various criteria and the vague information coming from decision-makers. The Decision-making Trial and Evaluation Laboratory (DEMATEL) technique structures the relationships among criteria, thereby constructing an influential network relationship map (INRM). Meanwhile the DEMATEL-based, analytical network process (ANP) method aids in obtaining influential weights of the criteria. Decision-makers may hold diverse opinions and preferences due to incomplete information, differences in knowledge or simply conflicts that are inherent between various departments. This can make it difficult to judge the performance of alternatives. One remedy is to apply a modified COmplex PRoportional ASsessment of alternatives with Grey relations. Next, this is applied to improve each criterion for integration of the performance values obtained in closing the aspiration level from different expert opinions based on INRM. An empirical example using data from a Taiwanese electronics company is provided to demonstrate our proposed method. The results can provide firms with a knowledge-based understanding of the source of some problems, thus reducing the performance gaps and closing the aspiration levels. Finally, there is a discussion on certain managerial implications. 相似文献
58.
Shyy's multiple one-dimensional adaptive grid method is modified to improve the grid skewness. A test problem of steady isotropic heat conduction illustrates that both the grid distortion and the accuracy of temperature distribution are improved significantly. 相似文献
59.
本文分析和证明了微量调速阀在实现2-100ml/min 的微量控制时,其压力补偿器的结构性自动抗污染机理和阀具有的综合抗污染性能、其抗污染的机理和性能对设计和研究低污染敏感度的液压元件有实际的指导意义. 相似文献
60.
Nan-Chyuan Tsai Jiun-Sheng Liou Chih-Che Lin Tuan Li 《Sensors and actuators. A, Physical》2010,157(1):68-76
For micro-gyroscopes, the angular rate detection components have to oscillate forwards and backwards alternatively. An innovative design of micro-electromagnetic drive module is proposed to make a Π-type thin disc reciprocally and efficiently rotate within a certain of angular interval. Twelve EM (Electromagnetic) poles, with iron cores at the center and wound by electroplated copper wires, enclosing the thin disc are designed to provide the magnetic drive power. Isotropic etching technique is employed to fabricate the high-aspect-ratio trench, housing of the follow-up electroplated copper, so that the contact angle of wire against trench can be increased and the potential defect of cavities and pores within the wire can be prevented. On the other hand, a Π-type thin disc, with a central bearing and a set of auxiliary bushing, is designed to conduct the pitch motion as an angular excitation, in addition to spinning, is exerted on the gyroscope. That is, the angular motion of the disc is two-dimensional: spinning, driven by the EM poles, and tilting, to respond to the exerted angular rate due to Coriolis effect.The efficacy of the micro-magnetic drive module is verified by theoretical analysis and computer simulations by the commercial software, Ansoft Maxewll. In comparison with the conventional planar windings in micro-scale systems, the magnetic drive force is increased by 150%. 相似文献