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101.
Yoon KJ Lee MH Kim GH Song SJ Seok JY Han S Yoon JH Kim KM Hwang CS 《Nanotechnology》2012,23(18):185202
A tri-stable memristive switching was demonstrated on a Pt/TiO?/Pt device and its underlying mechanism was suggested through a series of electrical measurements. Tri-stable switching could be initiated from a device in unipolar reset status. The unipolar reset status was obtained by performing an electroforming step on a pristine cell which was then followed by unipolar reset switching. It was postulated that tri-stable switching occurred at the location where the conductive filament (initially formed by the electroforming step) was ruptured by a subsequent unipolar reset process. The mechanism of the tri-stable memristive switching presented in this article was attributed to the migration of oxygen ions through the ruptured filament region and the resulting modulation of the Schottky-like interfaces. The assertion was further supported by a comparison study performed on a Pt/TiO?/TiO(2-x)/Pt cell. 相似文献
102.
Bo Gun Park Soohyun Kim Il-Doo Kim Yong Joon Park 《Journal of Materials Science》2010,45(14):3947-3953
LiMn2O4 thin films with three-dimensional (3D) structure were prepared by the sol–gel method. Polystyrene beads (300 nm) were dispersed
in the form of monolayers on Pt/Ti/SiO2/Si substrates, which were then used as templates for fabricating three-dimensionally ordered electrodes. A coating solution
prepared from acetylacetonate sources was dropped on the template-deposited substrates, which were then calcinated at 400 °C.
The templates were removed by calcinations, and a 3D structure was formed through an annealing process. The discharge capacity
of the 3D LiMn2O4 films was 1.63–3.03 μAh cm−2. The capacity loss over 100 cycles was approximately 18%, however, the 3D structure was not destroyed during cycling. 相似文献
103.
104.
本文主要论述了煤仓瓦斯自动排放系统的系统构成、系统工作原理及其应用效果,指出了该系统在高瓦斯矿井煤仓仓内瓦斯超限治理中具有很好的推广使用价值。 相似文献
105.
In this paper, the Self-Optimizing Inverse Method (Self-OPTIM) has been experimentally verified by identifying constitutive parameters solely based on prescribed boundary loadings without full-field displacements. Recently the Self-OPTIM methodology was developed as a computational inverse analysis tool that can identify parameters of nonlinear material constitutive models. However, the methodology was demonstrated only by numerically simulated testing with full-field displacement fields and prescribed boundary loadings. The Self-OPTIM is capable of identifying parameters of the chosen class of material constitutive models through minimization of an implicit objective function defined as a function of full-field stress and strain fields in the optimization process. The unique advantages of the Self-OPTIM includes: 1) model independency that is expected to open up a wide range of applications for various engineering simulations; 2) capabilities of parameter identification based solely on global measurements of boundary forces and displacements. In this paper, the Self-OPTIM inverse method is experimentally verified by using two different shapes of specimens made of AISI 1095 steel: 1) dog-bone and 2) notched specimens under a loading and unloading course. Parameters of a cyclic plasticity model with nonlinear kinematic hardening rule and associated flow theory are identified by the Self-OPTIM. Multiple tests and the inverse simulations are conducted to ensure consistent performance of the Self-OPTIM. The identified parameters are successively used to reconstruct the material response. 相似文献
106.
The solubility of red palm oil(RPO) in supercritical carbon dioxide(scCO_2) was determined using a dynamic method at 8.5–25 MPa and, 313.15–333.15 K and at a fixed scCO_2 flow rate of 2.9 g·min~(-1) using a full factorial design. The solubility was determined under low pressures and temperatures as a preliminary study for RPO particle formation using scCO_2. The solubility of RPO was 0.5–11.3 mg·(g CO_2)~(-1) and was significantly affected by the pressure and temperature. RPO solubility increased with pressure and decreased with temperature. The Adachi–Lu model showed the best-fit for RPO solubility data with an average relative deviation of 14% with a high coefficient of determination, R~2 of 0.9667, whereas the Peng–Robinson equation of state thermodynamic model recorded deviations of 17%–30%. 相似文献
107.
108.
Jung Tae ParkJoo Hwan Koh Dong Kyu RohYong Gun Shul Jong Hak Kim 《International Journal of Hydrogen Energy》2011,36(2):1820-1827
Bifunctional TiO2 nanoparticles with hygroscopic and proton-conductive properties were synthesized by grafting proton-conducting polymer, i.e. poly(styrene sulfonic acid) (PSSA) from TiO2 nanoparitlces via surface-initiated atom transfer radical polymerization (ATRP). These bifunctional TiO2-PSSA nanoparticles were blended with poly(vinylidene fluoride-co-chlorotrifluoroethylene)-graft-poly(styrene sulfonic acid), i.e. P(VDF-co-CTFE)-g-PSSA to give proton-conducting membranes for high temperature fuel cells. FT-IR, UV-visible spectroscopy and X-ray diffraction (XRD) results revealed bifunctional properties of TiO2-PSSA nanoparticles due to successful grafting of PSSA chains. Ion exchange capacity (IEC) of P(VDF-co-CTFE)-g-PSSA/TiO2-PSSA membranes was not significantly changed irrespective of TiO2-PSSA concentrations, representing almost fixed SO3− concentration in the membranes. In contrast, water uptake and proton conductivity of membranes continuously increased with increasing TiO2-PSSA concentrations, presumably due to hygroscopic, soft conducting property of nanoparticles. The results of thermal gravimetric analysis (TGA) also showed that all the membranes were stable at least up to 280 °C. 相似文献
109.
110.
Sumeyra Gun Mohan Edirisinghe Eleanor Stride 《Materials science & engineering. C, Materials for biological applications》2013,33(6):3129-3137
Magnetic microspheres were prepared using a single step coaxial electrohydrodynamic atomization technique at ambient temperature and pressure, with poly(lactic-co-glycolic acid) as the coating and iron oxide (Fe3O4) nanoparticles dispersed in polyethylene glycol as the encapsulated material. The morphology and particle size distributions of the prepared magnetic microspheres were investigated by scanning electron microscopy. The particles were spherical with mean diameters ranging from ~ 2 μm to 18 μm, depending on the combination of processing parameters (flow rate and applied voltage). Analysis by infrared spectroscopy and focused ion-beam sectioning confirmed incorporation of iron oxide nanoparticles into the microspheres and the prepared samples were shown to be responsive to an applied magnetic field. This study demonstrates a convenient method for the preparation of nanoparticle loaded microspheres, which could be used potentially as transverse relaxation contrast agents in magnetic resonance imaging, as well as for magnetically guided drug delivery. 相似文献