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761.
Kwang Suk Jang Hee Man Yang Jonghun Kim Jong Duk Kim 《Nanotechnology, IEEE Transactions on》2008,7(2):115-119
We report the photorefractive effect of a layer-structured liquid crystal cell using N3-chemisorbed mesoporous TiO2 layers as photoconductive layers. Well-organized mesoporous thin films were prepared using surfactant templates. N3 was chemisorbed on the mesoporous TiO2 layer to effectively generate excited electrons, which could be injected in the TiO2 layer and participate in the generation of a space-charge field in the LC cell. The prepared liqud crystal cell shows unique characteristics of an inorganic photoconductive layer, a temporal diffraction grating formation. 相似文献
762.
D Olde Weghuis ME Stoepker B de Leeuw E van den Berg RF Suijkerbuijk WM Molenaar B de Jong A Geurts van Kessel 《Canadian Metallurgical Quarterly》1994,9(4):288-291
In this case-control study, we investigated the role of Cryptosporidium in gastroenteritis in children < 6 years old. Six hundred fresh stool specimens were examined for various pathogenic parasites, bacteria, and rotaviruses. Wet-mount preparations, formaline-ether concentrations, and Sheather's floatation techniques were used to recover the parasite oocysts. Permanent stained slides using acid-fast stain and trichrome stains were prepared. Of 300 children with gastroenteritis symptoms, 20 (6.7%) had Cryptosporidium oocysts; seven of the 20 had concomitant infections so they were excluded from the counts. This infection rate is significantly different (Z = 2; p < 0.05) from that found in the control group (1.7%) of children who reported no symptoms. The most frequent symptoms reported beside diarrhea were abdominal pain, cramps, anorexia, nausea, vomiting, and fatigue. Contaminated drinking water is suspected to be the source of infection; other possible factors are discussed. 相似文献
763.
R Keul PC Heinrich G Müller-newen K Muller P Woo 《Canadian Metallurgical Quarterly》1998,10(9):729-734
Investigation of the agonist and two antagonists to interleukin 6 (IL-6) and their possible role in the pathogenesis of different sub-groups of juvenile chronic arthritis (JCA). Sera of 54 patients and 10 age-matched controls were tested: 20 with pauci-articular JCA, 12 with polyarticular JCA, and 22 systemic JCA. Interleukin 6, soluble interleukin 6 receptor (agonist), soluble gp130 and autoantibodies to IL-6 (antagonist to IL-6) were measured, as well as C-reactive protein as an indicator of disease activity. In addition, during fever two systemic JCA patients were analysed longitudinally for these parameters. There was a significant increase in soluble IL-6 receptor (sIL-6R) concentrations. No difference in the levels of soluble gp130 and autoantibodies to IL-6 in the systemic JCA group was found. In two patients the fever curves corresponded to the IL-6 levels measured. sIL-6R serum concentrations also showed a tendency to follow the fever. The authors have shown that in systemic JCA, the levels of sIL-6R, agonist of IL-6, were increased significantly compared to the other groups, while levels of antagonists to IL-6 were not changed in the face of increased levels of IL-6 in systemic JCA. These results suggest an imbalance of IL-6 homeostasis. 相似文献
764.
765.
Myung Jong Lee Jianling Zheng Xuhui Hu Hsin-hui Juan Chunhui Zhu Yong Liu June Seung Yoon Tarek N. Saadawi 《Communications Magazine, IEEE》2006,44(11):116-123
Over the past decade, wireless multihop ad hoc networks have received a tremendous amount of research focus, at the core of which lies the design problem for efficient routing algorithms to meet various scenarios and applications. The axiom, "one size doesn't fit all," continues to stand firmly to this day. In light of this, we introduce a new routing design concept - the component approach. We examine existing routing protocols and break them down into smaller building blocks, namely, routing components. The component analysis and classification results show that most routing protocols can be functionally decomposed into several basic routing components. This fact indicates that it is feasible to design a component-based routing (CBR) protocol. With a different realization for each basic routing component, it is expected that the routing behavior of CBR can be tailored to different application profiles and time-varying environment parameters at a reasonable cost 相似文献
766.
Pan J. Woo C. Chih-Yuh Yang Bhandary U. Guggilla S. Krishna N. Hua Chung Hui A. Bin Yu Qi Xiang Ming-Ren Lin 《Electron Device Letters, IEEE》2003,24(5):304-305
This work reports the first replacement (damascene) metal gate NMOSFETs with atomic layer deposition (ALD) TaN/PVD and electroplated Cu as the stacked gate electrode. Transistors with PVD TaN and PVD Ta electrode are also fabricated. Our data show that ALD TaN has the right work function for the N-MOSFETs. The Cu damascene process can reduce the gate resistivity. The ALD process has the advantage of reducing the stress and radiation damage to the gate oxide. The damascene process flow bypasses high temperature steps (>600/spl deg/C)-critical for metal gate and high-k materials. 相似文献
767.
Dynamics of fast dislocations 总被引:1,自引:0,他引:1
Plastic deformation of crystalline solids at ultra-high strain rates may involve dislocations moving at supersonic speeds, the feasibility of which has been demonstrated via molecular dynamics simulation. The motion of these dislocations in a crystal depends on the defects they encounter, which may slow, or even pin, them down. Recently, we have conducted a series of investigations on the dynamics of transonic dislocations during their interactions with other dislocations, small voids and small interstitial loops, using the molecular dynamics method. The results indicate that a transonic dislocation will be slowed down to subsonic speed by a subsonic dislocation in front of it, and that approaching dislocations at sufficiently high velocities may not form a stable dipole. Small defects, like voids and interstitial clusters, on the other hand, will only temporarily slow down a segment of the transonic dislocation, which absorbs the interstitial loop by forming jogs, and sweeps the void into a few smaller defects of vacancy type. Upon release from the clusters, this segment of dislocation regains speed and becomes transonic again. In view of the possible important role played by high-speed dislocations during high-speed deformation, and from the point of scientific interest, we summarize this series of investigations, and discuss their implications in the present paper. 相似文献
768.
A two-parameter transmission technique is described for online, in situ measurement of the bulk moisture content of grains using microwaves. This noncontacting 4.9-GHz system is configured so that a well-collimated TEM beam is transmitted through a layer of grain, e.g., moving on a conveyer or flowing in a chute. The changes in attenuation and phase serve as two independent measurement parameters from which the wet and dry basis weights (grams per square centimeter) and moisture can be found using a linear model, independent of the layer thickness. If the layer thickness is also known, the wet and dry densities (grams per cubic centimeter) and complex dielectric constant can be found 相似文献
769.
Woo Young Choi Byung-Yong Choi Dong-Soo Woo Jong Duk Lee Byung-Gook Park 《Nanotechnology, IEEE Transactions on》2003,2(4):210-216
We proposed "reverse-order source/drain formation with double offset spacer" (RODOS) structure for low-power and high-speed applications. Both simulation and experimental data were used to evaluate the potential of the structure. It showed improved performance in terms of poly-depletion effect, dc characteristics, gate delay (CV/I), switching energy (CV/sup 2/) and linearity (V/sub IP3/). It satisfied all the requirements of LOP and LSTP for 90 nm technology node in ITRS 2002. Simulation predicted 794 /spl mu/A//spl mu/m in on-current, 0.1 nA//spl mu/m in off-current, 65 mV/V in DIBL, 80 mV/dec in SS, 1.29 ps in gate delay, 198 GHz in f/sub T/ and 0.151 fJ in switching energy in addition to enhanced linearity. Finally, we confirmed the high feasibility and potential of the RODOS MOSFET's for low-power and high-speed applications such as an LNA in portable communication appliances. 相似文献
770.
This article proposes a method for the global optimization of redundancy over the whole task period in a kinematically redundant manipulator. The necessary conditions based on the calculus of variations for integral-type criteria result in a second-order differential equation. For a cyclic task, the boundary conditions for conservative joint motions are discussed. Then, we reformulate a two-point boundary value problem to an initial value adjustment problem and suggest a numerical search method based on the iterative optimization for providing a globally optimal solution using the gradient projection method. Since the initial joint velocity is parameterized with the number of redundancy, we only search parameter values in the parameterized space using the configuration error between the initial and final time. We show through numerical examples that multiple nonhomotopic extremal solutions satisfying periodic boundary conditions exist according to initial joint velocities for the same initial configuration. Finally, we discuss an algorithm for topological liftings of the paths and demonstrate the generality of the proposed method by considering the dynamics of a manipulator. 相似文献