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排序方式: 共有3416条查询结果,搜索用时 15 毫秒
1.
Chou Y.C. Leung D. Lai R. Grundbacher R. Barsky M. Kan Q. Tsai R. Wojtowicz M. Eng D. Tran L. Block T. Liu P.H. Nishimoto M. Oki A. 《Electron Device Letters, IEEE》2003,24(6):378-380
The authors have investigated the reliability performance of G-band (183 GHz) monolithic microwave integrated circuit (MMIC) amplifiers fabricated using 0.07-/spl mu/m T-gate InGaAs-InAlAs-InP HEMTs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel on 3-in wafers. Life test was performed at two temperatures (T/sub 1/ = 200 /spl deg/C and T/sub 2/ = 215 /spl deg/C), and the amplifiers were stressed at V/sub ds/ of 1 V and I/sub ds/ of 250 mA/mm in a N/sub 2/ ambient. The activation energy is as high as 1.7 eV, achieving a projected median-time-to-failure (MTTF) /spl ap/ 2 /spl times/ 10/sup 6/ h at a junction temperature of 125 /spl deg/C. MTTF was determined by 2-temperature constant current stress using /spl Delta/G/sub mp/ = -20% as the failure criteria. The difference of reliability performance between 0.07-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with pseudomorphic In/sub 0.75/Ga/sub 0.25/As channel and 0.1-/spl mu/m InGaAs-InAlAs-InP HEMT MMICs with In/sub 0.6/Ga/sub 0.4/As channel is also discussed. The achieved high-reliability result demonstrates a robust 0.07-/spl mu/m pseudomorphic InGaAs-InAlAs-InP HEMT MMICs production technology for G-band applications. 相似文献
2.
Dynamic Programming (DP) applies to many signal and image processing applications including boundary following, the Viterbi algorithm, dynamic time warping, etc. This paper presents an array processor implementation of generic dynamic programming. Our architecture is a SIMD array attached to a host computer. The processing element of the architecture is based on an ASIC design opting for maximum speed-up. By adopting a torus interconnection network, a dual buffer structure, and a multilevel pipeline, the performance of the DP chip is expected to reach the order of several GOPS. The paper discusses both the dedicated hardware design and the data flow control of the DP chip and the total array.This work was supported in part by the NATO, Scientific and Environmental Affairs Division, Collaborative Research Grant SA.5-2-05(CRG.960201)424/96/JARC-501. 相似文献
3.
This is a study of the differences in the risk factors for being either hepatitis B surface antigen positive [HBsAg(+)] or antibody to hepatitis C virus positive [Anti-HCV(+)] in A-Lein, a rural area in southern Taiwan, an area which also has a high hepatoma mortality rate. Three hundred eighty-five patients age > or =40 years participated in hepatoma screening at the A-Lein Community Health Center during 1995. Those who were HBsAg(-) and anti-HCV(-) or had coinfection of HBsAg(+) and anti-HCV(+) were excluded, leaving 293 patients: 109 HBsAg(+) and 184 anti-HCV(+). The anti-HCV(+) patients had a lower socioeconomic status (as defined by level of education and type of occupation) and were older than HBsAg(+) patients (P < 0.05). Those with higher alanine aminotransferase levels (ALT) also had a higher anti-HCV(+) to HBsAg(+) odds ratio (OR), and a dose response relationship was found, P < 0.0001. Anti-HCV(+) patients were more likely than HBsAg(+) patients to have a spouse who shared the infection, OR = 5.11; 95% CI, 2.30-11.28. Anti-HCV(+) patients were more likely than HBsAg(+) patients to have had blood transfusions (OR = 2.66; 95% CI, 1.20-5.89), frequent medical injections (OR = 2.64; 95% CI, 1.62-4.31), or injections by non-licensed medical providers (OR = 1.91; 95% CI, 1.18-3.09). Multiple logistic regression analysis showed that the significant factors for anti-HCV(+) patients vs. HBsAg(+) patients are drinking habit (OR = 3.45; 95% CI, 1.02-11.60), age (OR = 6.33; 95% CI, 2.93-13.68), and frequent medical injections (OR = 2.88; 95% CI, 1.65-5.03). The transmission of hepatitis C in A-Lein is closely related to low socioeconomic status, age, alcohol abuse, spouses being anti-HCV(+), and frequent medical injections, especially from non-licensed medical providers, including both pharmacists and those with no medical licensing whatsoever. These nonlicensed medical providers sometimes reuse needles to save money, which is a likely route of infection. 相似文献
4.
The tool portfolio of a plant refers to the makeup, in quantity and type, of processing machines in the plant. It is determined by taking into consideration the future trends of process and machine technologies and the forecasts of product evolution and product demands. Portfolio planning is also a multicriteria decision-making task involving tradeoffs among, investment cost, throughput, cycle time, and risk. Tool portfolio planning is a complex task that has strong bearing on manufacturing efficiency. In the first part of this paper, a multicriteria economic decision model is presented for optimal configuration. of the portfolio and to determine the optimal factory loading. The second and third parts of the paper contain applications of the model. If plants are closely located or have a twin-plant design, portfolio planning at multiple plants can be integrated to enhance the overall effectiveness of portfolios. In the second part, a novel methodology for arbitrating capacity backup between plants is described. Because the economic model is constructed upon a valuation of both cycle time and throughput, it is a suitable method for the evaluation of cycle time reduction projects. The application procedure is outlined in the third part. 相似文献
5.
The stress buffer layer (SBL) is a widely applied improvement in many advanced packages used to release the stress concentration at solder joints. However, it has been generally found that the metal line adjacent to the SBL may suffer larger deformation and its reliability should be addressed. In this study, the panel level package (PLP) technology with solder on polymer (SOP) structure is selected as the testing sample to investigate the effect of SBL. The ball shear strength test is conducted first to investigate the reliability of metal trace in PLP. In addition, finite element (FE) analysis is applied to understand the actual thermo-mechanical behavior of PLP after its assembly. The package-level and board-level reliability assessments are compared, and the suggested layout of the redistribution layer on the SBL is provided herein. 相似文献
6.
Tahui Wang Chimoon Huang Chou P.C. Chung S.S.-S. Tse-En Chang 《Electron Devices, IEEE Transactions on》1994,41(9):1618-1622
A two-dimensional numerical simulation including a new interface state generation model has been developed to study the performance variation of a LDD MOSFET after a dc voltage stress. The spatial distribution of hot carrier induced interface states is calculated with a breaking silicon-hydrogen bond model. Mobility degradation and reduction of conduction charge due to interface traps are considered. A 0.6 μm LDD MOSFET was fabricated. The drain current degradation and the substrate current variation after a stress were characterized to compare the simulation. A reduction of the substrate current at Vg ≃0.5 Vd in a stressed device was observed from both the measurement and the simulation. Our study reveals that the reduction is attributed to a distance between a maximum channel electric field and generated interface states 相似文献
7.
8.
Thick films of superconducting oxides, YBa2Cu3O7-, were successfully made by conventional screen-printing technology on Al2O3, MgO, and ZrO2 substrates. Interdiffusion between the superconductive film and substrate was investigated using analytical electron microscopy. The results indicate that MgO and ZrO2 are superior to Al2O3 for substrate materials. 相似文献
9.
The structure of silica gels derived from tetraethoxysilane (TEOS) with molar compositions of TEOSH2OHNO3=1100.4 and then aged in various solvents, was studied. The effect of various solvents having different physical properties on the gel structure, as well as the relationship between the solvent properties and the dried gel structure, were investigated. The density, surface area and pore-size distribution were measured. The results of the pore structure and SEM showed the aged gels to have a slit-shaped micropore, narrow pore-size distribution, and homogeneous microstructure. The density, surface area, pore size and pore volume of dried gels changed as the gels were subjected to ageing in various solvents. The surface area could be related to the polarity parameter of the ageing solvent. 相似文献
10.
Process simulation and fabrication of advanced multi-step three-dimensional braided preforms 总被引:3,自引:0,他引:3
The fundamentals of multi-step braiding for the fabrication of three-dimensional fibre preforms for composites have been studied. To facilitate the understanding of the complex multi-step braiding processes, a computer simulation algorithm has been developed. The simulation acts as a tool to allow the identification of individual yarn paths, number and location of yarn groups, and braid geometry. It was found that individual control of the rows and columns of yarn carriers on a Cartesian braiding bed allows for the fabrication of advanced multi-step braids; the micro-structural possibilities of three-dimensional braids are thus greatly extended. Some basic relationships of the braiding parameters have been identified. It has been concluded that the traditional four-step and two-step braidings are special cases of multi-step braidings. To verify the feasibility of the structures, experimental investigations have also been carried out. Innovative braid architectures have been designed and fabricated using a prototype multi-step braiding machine. 相似文献