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91.
H. C. Yadav Rajeev Jain A. R. Singh P. K. Mishra 《The International Journal of Advanced Manufacturing Technology》2013,67(9-12):2137-2155
An amicable aesthetical design of a product is prudent for its wide acceptability and viability. Selection of shape parameters with customer satisfaction is critical in aesthetical design and a challenging task for designers. In the present work, the authors proposed a sequential approach to design a car profile with aesthetical aspects. The methodology is based on Kano model that provides a framework for incorporation of customer satisfaction with the design requirements. Further, Taguchi's robust design approach has been used to find the optimum level of the parameter to achieve initial design estimates and thereafter, response surface method (RSM) is applied to refine the optimum values, precisely. The methodology has been illustrated with a case study. 相似文献
92.
Abhijit P. Brahme Kaan Inal Raja K. Mishra Shigeo Saimoto 《Computational Materials Science》2011,50(10):2898-2908
This paper presents a crystal plasticity based finite element analysis employing the new microstructure-based strain hardening model recently presented by Saimoto and Van Houtte (2011) [7] to simulate formability and texture evolution in the commercial aluminum alloy 5754. Simulations are performed to compare the predictive capability of the new hardening model against the common work hardening models using a rate-dependent plasticity formulation. The parameters in the numerical models are calibrated using the X-ray data published by Iadicola et al. (2008) [9] for the aluminum sheet alloy 5754. The predictions of the model for balanced biaxial tension and in-plane plane-strain tests are compared against experimental observations presented in Iadicola et al. (2008) [9]. It is concluded that the new model provides the best predictions of the large strain behavior of Aluminum sheet alloy 5754 subjected to various strain paths. 相似文献
93.
Rowdra Ghatak Dipak R. Poddar Rabindra K. Mishra 《AEUE-International Journal of Electronics and Communications》2009,63(4):279-286
This article compares input impedances and radiation characteristics of half wavelength Koch fractal V–electric dipoles having included angles 60°, 90° and 120°. The study considers three structures. In the 1st structure the Koch arms open into the V-region, in 2nd structure they open away from the V-region and in the third structure, one arm opens into and the other away from the V-region. A first iteration, structure 1 of V-Koch electric dipole antenna with included angle of 120° was fabricated and the experimental return loss was in good agreement with simulation. At their first resonances the antennas’ gain and input resistance decrease with decrease in included angles, an observation synonymous to Euclidian electric dipoles. In terms of gain, the first structure is found to give better performance than the other two. For this structure, the pattern distortion at the second resonance was also less compared to the other structures. 相似文献
94.
Role of boron in low carbon aluminum-killed cold rolled batch annealed steels has been critically examined. It was found that
it is not the absolute boron but B/N ratio that controls the forming properties. Pancake shaped grains (high grain shape anisotropy)
are highly desirable for improving the desirable {111} texture, normal anisotropy, and draw ability of the steel sheets. Microstructural
analysis showed that the extent of pancaking decreases with increase in B/N atomic ratio and reaches ultimately to formation
of equiaxed grains. Low B/N ratio (upto 0.3) resulted in improved mean plastic anisotropy ratio (r
m) value and high grain shape anisotropy, which has been characterized through grain aspect ratio. The desirable orientation
in steel with low B/N ratio is attributed to sufficient availability of Al and N to precipitate during batch annealing. Optimum
amount of boron, aluminum, and nitrogen in steel has resulted in coarse pancake structure, which is ideally suited for improved
formability. 相似文献
95.
Jidong Kang David S. Wilkinson Raja K. Mishra J. David Embury Elhachmi Essadiqi Amjad Javaid 《Journal of Materials Engineering and Performance》2013,22(5):1386-1395
There are considerable data in the literature dealing with deformation mechanisms in AZ31 sheets. However, there is little information on the damage and fracture processes in this material. In this contribution, digital image correlation is used to follow deformation patterns occurring during tensile and v-bending tests at room temperature. A variety of surface analysis techniques and three-dimensional x-ray tomography have been used to examine the relationship between deformation, damage initiation, and the final fracture processes. The results show that premature diffuse necking occurs in the tensile tests without transit into localized necking. Deformation twins cluster by an autocatalytic process to form shear bands serving as preferential sites for strain localization and crack initiation. Damage appears in the form of microcracks within the shear bands at a late stage of necking and lead to the final fracture. The presence and the distribution of second-phase particles and their distributions help accelerate the final fracture processes. 相似文献
96.
Randhir Singh Kaushik Das Abhijeet K. Mishra Nabakishore Kalo 《Transactions of the Indian Institute of Metals》2017,70(7):1795-1804
Numerical models of a cathode block assembly in a Hall–Hèroult cell, comprising of liquid aluminium, carbon block, current collector, ramming paste and a copper insert were built and the finite element method simulations were carried out to model the cathode voltage drop (CVD), the current distribution and, the effect of geometrical parameters on the CVD. The objective of the study was to quantify the drop in the CVD for different cathode assembly design. Flat- and inclined-interface carbon block top-surface and a copper insert versus the conventional insert-free designs were simulated with a myriad of other geometrical parameters to optimise the design. The results informed about the optimum insert positioning to about 75 mm from the collector base and the energy saving possibilities due to reduction in the CVD with a cathode design with inclined-interface carbon block and copper insert in the collector bar. 相似文献
97.
Sediment TMDL Development for the Amite River 总被引:1,自引:0,他引:1
The Amite River is recognized as one of the 15 water bodies impaired by sediments in Louisiana, USA. Based on US EPA’s Protocol
sediment TMDL (Total Maximum Daily Load) development is conducted for the Amite River and described in this paper. The TMDL
development consists of four components: (1) development of a new model for cohesive sediment transport, (2) estimation of
sediment loads (sources) due to watershed erosion, (3) river flow computation, and (4) determination of sediment TMDL for
the Amite River. Using the mass conservation principle and Reynolds transport theorem a new 1-D model has been developed for
computation of suspended cohesive sediment transport. Sediment erosion in the Amite River Basin is calculated by combining
the USLE (Universal Soil Loss Equation) model with GIS and the digital elevation model of the Amite River Basin. Digital elevation
data was imported into the GIS which generated inputs for USLE. The calculated average annual rate of soil erosion in the
Amite River Basin is 13.368 tons per ha, producing a nonpoint sediment load of 103 mg/L to the Amite River. The flow computation
is performed using the HEC-RAS software. The computed sediment concentration in the Amite River varies in the range of 3–114 mg/L
and sediment TMDL is 281.219 tons/day. The reduction necessary to support beneficial uses of the river is 55% or 275.946 tons/day.
Results indicate that the combined application of the new 1-D sediment transport model, GIS, USLE model, and HEC-RAS is an
efficient and effective approach to sediment TMDL development. 相似文献
98.
The objective of this study was to compare the performance of cellulose acetate (CA) and ethylcellulose (EC)-HPMC combination coatings as semipermeable membranes (SPMs) for osmotic pump tablets (OPTs) of naproxen sodium (NPS) so as to deliver a constant, predetermined amount of drug in solution form over a fixed span of time, independent of external environmental conditions. Osmotic pump tablets were designed with different coating variables and optimized in terms of nature of plasticizer, membrane thickness, and orifice diameter. The effect of insertion of an inner microporous film around the NPS core to minimize deformation of the SPM due to peristaltic movement of the gut was also studied. Osmotic pump tablets composed of membranes with water-soluble plasticizer, propyleneglycol (PG), released drug mainly through diffusion, whereas those designed with CA and EC-HPMC (4:1) coats containing water-insoluble plasticizer, castor oil, released their contents by perfect zero-order kinetics over a prolonged period of time, though the average release rate that could be achieved with the EC-HPMC (4:1) membrane was only about half the rate achieved with the CA membrane for the same membrane thickness. Release rates for both the membranes decreased with increasing membrane thickness and were found to be independent of orifice diameter, agitation intensity, and pH of the dissolution medium. 相似文献
99.
A Nuclear Power Project is being set-up at KudanKulam in the state of Tamil Nadu, India in collaboration with the Russian Federation. The project comprises of two units each of 1000 MWe VVER type reactor. The design of the plant and supply of all the major equipment is in the scope of the Russian Federation while development of infrastructure and project construction is in Indian scope of works. The VVER (Version V-412) reactor that is under construction at KudanKulam site is an advanced PWR, which incorporates all the features of a modern PWR as per the current Russian, Western and IAEA standards. The KudanKulam site in the southern Indian state of Tamil Nadu was one among the several sites evaluated by the Site Selection Committee, which cleared KudanKulam site for setting up an installed capacity up to 6000 MWe. The design, construction and operation of the plant meets the regulatory and licensing requirements of Russian regulatory body “RTN” as also India's Atomic Energy Regulatory Board. The supply of the equipment from the Russian Federation is on schedule and the project construction work by various Indian agencies is also ahead of schedule. The two units of KudanKulam Nuclear Power Project (KKNPP) are scheduled to achieve first criticality in the year 2007–2008. The paper discusses various design features, project construction and management aspects. 相似文献
100.
Harmonic estimation for a signal distorted with additive noise has been an area of interest for researchers in many disciplines of science and engineering. This work presents a new algorithm based on the foraging behavior of E. coli bacteria in our intestine to estimate the harmonic components present in power system voltage/current waveforms. The basic foraging strategy is made adaptive, through a Takagi-Sugeno fuzzy scheme, depending on the operating condition to make the convergence faster. Besides, the harmonic estimation is linear in amplitude and nonlinear in phase. As the proposed algorithm does not rely on Newton-like gradient descent methods, this is used for phase estimation whereas the linear least square scheme estimates the amplitude, thereby presenting the hybrid method. The improvement in %error, as well as the processing time compared with the conventional discrete Fourier transform and genetic algorithm method is demonstrated in this paper. Besides, the performance is quite acceptable even in the presence of decaying dc component as well as to change in amplitude and phase angle of harmonic components. 相似文献