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111.
The Journal of Supercomputing - Rapid advances in interconnection networks in multiprocessors are closing the gap between computation and communication. Given this trend, how can we utilize fast... 相似文献
112.
113.
In recent years, the state of the art in shape optimization has advanced due to new approaches proposed by various researchers. A fundamental difficulty in shape optimization is that the original finite element mesh may become invalid during large shape changes. Automatic remeshing and velocity field approaches are most commonly used for conventionalh-type finite element analysis to address this problem.In this paper, we describe a different approach to shape optimization based on the use of high-orderp-type finite elements tightly coupled to a parameterized computational geometry module. The advantages of this approach are as follows.Accurate results can be obtained with much fewer finite elements, so large shape changes are possible without remeshing.Automatic adaptive analysis may be performed so that accurate results are achieved at each step of the optimization process.Since the elements derive their geometric mapping from the underlying geometry, the fundamental equivalent of velocity field element shape updating may be readily achieved.Results are presented for sizing and shape optimization with this approach and contrasted with previous results from the literature. 相似文献
114.
King NL 《Meat science》1984,11(1):59-72
By extracting cooked meat products with 6 m guanidine hydrochloride and then dialysing the extract into 1 % Triton X-100, the activity of adenylate kinase (AK) and creatine kinase (CK) may be at least partly recovered, provided the meat was not heated above ≈120°C (AK) or ≈105°C (CK). A wide range of animal species may be identified in cooked meats by staining isoelectricfocusing gels for these two enzymes. However, if a sample consists of mixed flesh from different species, hybrid creatine kinase dimers form during dialysis and the additional bands complicate interpretation of gel patterns. 相似文献
115.
Summary The extent to which a low-aspect-ratio flat ship with a chined hull is wetted when planing at infinite Froude number is investigated. A numerical method of solution for the wetted area, which is applicable to more general planing problems, is presented. The results obtained by this method are compared with those found by solving the inverse problem of determining the hull shape which produces a given waterplane shape and are shown to be in excellent agreement. Results are also presented which indicate that a vertical chine may be used to fix the shape of the wetted region. 相似文献
116.
The rate of recession of the topochemical interface between a porous core and the product layer is shown to be given by
wherer
c is radial position of the interface,R(rc) the rate of the chemical reaction at the interface and (dC
s/dr)|r
s is the gradient of concentration profile of solid reactant in the porous core at the interface. The integration of the above
equation can sometimes be achieved analytically but can always be done numerically for even highly complex reaction mechanisms.
The equation correctly reduces to previously known solutions when the inner core is impervious to gas diffusion. The utility
of the equation is demonstrated by applying it to the industrially important multistage reduction process Mn3O4 → MnO — > Mn. The predictions from the theoretical model are compared successfully with experimental data for this reaction.
Formerly Student in Department of Metallurgy, University of Strathclyde, Scotland. 相似文献
117.
Crazes are produced on two orthogonal planes in both thin film and macroscopic samples of polystyrene by sequentially applying two orthogonal tensile strains
1 and
2. Although many crazes produced by the second strain
2 (secondary crazes) are stopped when they meet a primary craze, some intersections occur. The fraction of craze meetings resulting in intersection increases from 20% at
1=
2=3% to 55% at
1=
2=5%; intersections also occur preferentially in thin regions of primary crazes. The craze fibril structure in the intersection has a much lower fibril volume fraction, v
f, than either of the two crazes from which it formed. The fibril volume fraction in the intersection is approximately given by the product of the fibril volume fractions of the two crazes, in agreement with a prediction based on the surface drawing mechanism of craze thickening. At higher strain levels the v
fs of the intersections are lower, leading to higher fibril stresses and enhanced fibril fracture; an increasing fraction of intersections breaks down to form large voids at these higher strain levels. Fractography of macroscopic samples containing intersecting crazes demonstrates that voids formed at the intersections can act as nuclei for cracks causing premature fracture of the material. 相似文献
118.
Two simple and effective control strategies for a multi-axle heavy truck, modified skyhook damping (MSD) control and proportional-integration-derivative (PID) control, were implemented into functional virtual prototype (FVP) model and compared in terms of road friendliness and ride comfort. A four-axle heavy truck-road coupling system model was established using FVP technology and validated through a ride comfort test. Then appropriate passive air suspensions were chosen to replace the rear tandem suspensions of the original truck model for preliminary optimization. The mechanical properties and time lag of dampers were taken into account in simulations of MSD and PID semi-active dampers implemented using MATLAB/Simulink. Through co-simulations with Adams and MATLAB, the effects of semi-active MSD and PID control were analyzed and compared, and control parameters which afforded the best comprehensive performance for each control strategy were chosen. Simulation results indicate that compared with the passive air suspension truck, semi-active MSD control improves both ride comfort and road-friendliness markedly, with optimization ratios of RMS vertical acceleration and RMS tyre force ranging from 10.1% to 44.8%. However, semi-active PID control only reduces vertical vibration of the driver’s seat by 11.1%, 11.1% and 10.9% on A, B and C level roads respectively. Both strategies are robust to the variation of road level. 相似文献
119.
The rôle of carboxyl proteases in tenderising meat was investigated by injecting the inhibitors, pepstatin and EPNP, into pre-rigor muscle. The increase in shear force values induced by these inhibitors provided a minimum estimate of the extent to which endogenous carboxyl proteases normally tenderise meat at 60°C.Gel electrophoresis showed that connectin was hydrolysed to a greater extent than other muscle proteins at this temperature and that breakdown of connectin was inhibited by pepstatin and EPNP. Thus it is likely that, when intact, connectin may contribute to the strength of cooked meat. 相似文献
120.
An ontology of scientific experiments 总被引:1,自引:0,他引:1