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111.
This paper presents a Fuzzy Neural Network (FNN) control system for a traveling-wave ultrasonic motor (TWUSM) driven by a dual mode modulation non-resonant driving circuit. First, the motor configuration and the proposed driving circuit of a TWUSM are introduced. To drive a TWUSM effectively, a novel driving circuit, that simultaneously employs both the driving frequency and phase modulation control scheme, is proposed to provide two-phase balance voltage for a TWUSM. Since the dynamic characteristics and motor parameters of the TWUSM are highly nonlinear and time-varying, a FNN control system is therefore investigated to achieve high-precision speed control. The proposed FNN control system incorporates neuro-fuzzy control and the driving frequency and phase modulation to solve the problem of nonlinearities and variations. The proposed control system is digitally implemented by a low-cost digital signal processor based microcontroller, hence reducing the system hardware size and cost. The effectiveness of the proposed driving circuit and control system is verified with hardware experiments under the occurrence of uncertainties. In addition, the advantages of the proposed control scheme are indicated in comparison with a conventional proportional-integral control system. 相似文献
112.
The hot-working characteristics of wrought Co-Ni-Cr-Mo implant alloy during ingot-to-billet conversion were evaluated using a Gleeble-2000A simulator. The hot tensile test at 700–1 320 °C was used to determine the optimum hot-working parameters at a strain rate equivalent to that of conventional press forging to ensure acceptable hot workability. Hot ductility and deformation resistance as a function of temperature can be clearly established. The fracture surfaces of the tensile specimens were examined to correlate them with the hot tensile ductility values at various temperatures. The poor ductility at temperatures above 1300 °C was attributed to the incipient melting of grain boundaries. The effect of temperature and strain rate on the flow-stress behaviour and microstructures were investigated by uniaxial compression testing in the temperature range 900–1200 °C and strain rate, , range of 0.01–10s–1. The strain-hardening and steady-state behaviour were described from the measured true stress-true strain curves. 相似文献
113.
Formation of y hydrides in α titanium involves a hcp → fct lattice transformation with hydrogen as an interstitial diffusing
species. Since the crystallography of this reaction resembles that of a martensitic transformation and the hydrides form at
temperatures where both titanium and hydrogen atoms may have negligible mobility, many investigators have concluded that γ
hydrides form by a martensitic mechanism. In this study, the lengthening kinetics of
γ hydrides were determined using conventional transmission electron microscopy (TEM). The length of the hydrides was measured
as a function of time, temperature, and hydrogen concentration in samples isothermally aged in the range of 25 °C to 80 °C.
These measurements were compared with the Zener-Hillert model of volume-diffusion-controlled precipitate growth. The experimental
results indicate that y hydride growth is diffusionally controlled at 25 °C and possibly interfacially controlled at aging
temperatures of 50 °C and higher. These and other aspects of the transformation are discussed. 相似文献
114.
Wu-Chiang Chan Ping-Chuan Chen Meng-Chin Tsai Ting-Ko Chen 《Engineering Management Journal; EMJ》2017,29(2):87-98
Open innovation has transformed internal novel resource allocation and facilitated diverse interorganizational cooperation models. Previous studies have investigated open innovation archetypes and their formation. However, most researchers have neglected the crucial role that team leaders play in integrating internal and external resources and connecting creative ideas in open innovation. This study investigated the influence of open innovation archetypes and team leaders’ innovation traits on team performance. On the basis of the literature review, the analytical hierarchy process was applied to construct a framework for assessing and selecting team leaders in open innovation. The analysis was completed based on samples from 45 valid respondents (88% return rate) in Taiwan’s high-tech industry. The study results suggested that innovation knowledge is the most crucial innovation criterion for a leader, particularly core knowledge and advanced knowledge. Among the various sub-criteria, extrinsic motivation was the second most important sub-criterion. Leaders with strong innovation motivations are suitable to lead inbound open innovation projects. 相似文献
115.
Volodin V. N. Tuleushev Yu. Zh. Zhakanbaev E. A. Tsai K. V. Rofman O. V. 《Technical Physics Letters》2017,43(1):126-129
Carbon–lead solid solutions coexisting with amorphous carbon have been obtained for the first time in a film coating deposited by ion-plasma sputtering. During subsequent vacuum annealing of carbon–lead films containing more than 68.5 at % Pb, this element almost completely evaporates to leave an amorphous carbon coating on a substrate. During annealing at 1100°C, this amorphous carbon crystallizes into a new hexagonal lattice with unit cell parameters a = 0.7603 nm and c = 0.8168 nm. Characteristic X-ray diffraction data for the identification of this phase are determined.
相似文献116.
S. F. Tsai 《International Journal of Thermophysics》2016,37(3):31
The application of a thermal analysis model to estimate the temperature depression from the ideal fixed-point temperature is important, especially when the chemical analysis of the sample in a cell is insufficient or the cell might have been contaminated during fabrication. This study extends previous work, on thermal analysis with the tin point, to an investigation of the impurity dependence of the silver-point temperature. Close agreement was found between the temperature depression (\(-0.36\) mK) inferred from the thermal analysis of the measured fixed-point plateau and the temperature depression (\(-0.32\) mK) inferred using the sum of individual estimates (SIE) method with an impurity analysis based on glow discharge mass spectrometry. Additionally, the results of the thermal analysis manifest no significant dependence on the rate of solidification, and the scatter of observed gradients was within 0.36 mK among five plateaux with different temperature settings of the furnace. Although the results support the application of both the SIE method and thermal analysis for the silver point, further experiments with cell-to-cell comparisons linked to thermal analysis, a study of the thermometer-furnace systematic effects, the oxygen effect, and the locus of the freezing plateau should be investigated to reach a firm conclusion. 相似文献
117.
Reinforced concrete (RC) walls play an important role in resisting earthquakes, so understanding the lateral load-deformation response of an RC wall subjected to an axial load, shear, and moment is essential to nonlinear structural analysis. In this study, the moment-bending deformation response of an RC wall under an axial load and moment is obtained from moment–curvature analysis using the wall’s proper plastic hinge length. Furthermore, modified compression-field theory, adjusted according to the height–length ratio of the wall, is used to calculate the shear–shear deformation response of the wall under an axial load and shear. By integrating the moment-bending deformation and the shear–shear deformation responses, the lateral load-deformation response of the RC wall under axial load–moment–shear interaction can be reasonably determined. To confirm the reliability of the proposed method, experimental results for 67 RC walls are compared with analysis results from the proposed method. The statistical results show that the proposed method accurately predicts the lateral ultimate load but somewhat underestimates the lateral ultimate deformation. Finally, this paper gives an example using an equivalent column to simulate an RC wall using SAP2000 pushover analysis. 相似文献
118.
Control of the Metal–Insulator Transition at Complex Oxide Heterointerfaces through Visible Light 下载免费PDF全文
119.
Tomohiro Tabata Ou Zhang Yuna Yamanaka Peii Tsai 《Clean Technologies and Environmental Policy》2016,18(6):1735-1744
The paper discusses development of a method for estimating disaster waste that can be potentially generated by a natural disaster in the future for pre-disaster waste management. In particular, this research focuses on micro-disaster waste originating from household consumer durables. We documented the number of household consumer durables and built a mass per unit database of major consumer durables using web-based and statistical surveys. We also estimated present and future figures of disaster waste that can be generated in the study area. The estimated total amount of disaster waste that could be generated in 2015 was 24.1 kt (18.1–29.8 kt) and 108 kt (81.8–133 kt) for Kobe City and Ise-Shima region, respectively. The total quantities of TV sets, air conditioners, refrigerators, and washing machines generated in Kobe and Ise-Shima will range between 10.9 and 22.8 kt (247,000–545,000 units) in 2015, and 10.7 kt to 22.8 kt (249,000–550,000 units) in 2035. The quantity estimated for 2015 is equal to 61 % of the annual processing capacity of Plant A, Japan’s leading home appliances recycling plant. Finally, we discussed the contribution of the estimation results and geographic information systems in future recycling planning. 相似文献
120.