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991.
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993.
G.K. DEY 《Mineral Processing and Extractive Metallurgy Review》2013,34(2):463-476
Abstract The processing of refractory metal intermetallic compounds by micropyretic synthesis has been discussed in this article. The advantages of this process have been elaborated with the synthesis of intermetallic compounds in view. Microstructures of the synthesized alloys have been examined in detail and compared with the conventionally produced microstructure. The effect of different process parameters on the process and on the synthesized microstructure has been described. Special emphasis is given on the synthesis of aluminides of Nb and Ti and NiTi. The mechanism of micropyretic synthesis of the aforementioned intermetallic compounds from elemental powders has been studied by arresting the synthesis process midway. This has resulted in preservation of the unsynthesized material on one side, the fully synthesized material on the other and intermediate stages of synthesis frozen in between. A detailed microstructural characterization has been carried out around the arrested synthesis front in order to establish the sequence of synthesis. 相似文献
994.
《Organic Electronics》2014,15(4):871-877
Transition metal oxides (TMOs) on organic semiconductors (OSs) structure has been widely used in inverted organic optoelectronic devices, including inverted organic light-emitting diodes (OLEDs) and inverted organic solar cells (OSCs), which can improve the stability of such devices as a result of improved protection of air sensitive cathode. However, most of these reports are focused on the anode modification effect of TMO and the nature of TMO-on-OS is not fully understood. Here we show that the OS on TMO forms a two-layer structure, where the interface mixing is minimized, while for TMO-on-OS, due to the obvious diffusion of TMO into the OS, a doping-layer structure is formed. This is evidenced by a series of optical and electrical studies. By studying the TMO diffusion depth in different OS, we found that this process is governed by the thermal property of the OS. The TMO tends to diffuse deeper into the OS with a lower evaporation temperature. It is shown that the TMO can diffuse more than 20 nm into the OS, depending on the thermal property of the OS. We also show that the TMO-on-OS structure can replace the commonly used OS with TMO doping structure, which is a big step toward in simplifying the fabrication process of the organic optoelectronic devices. 相似文献
995.
Dae-Woon Jeong Hyun-Suk Na Jae-Oh Shim Won-Jun Jang Hyun-Seog Roh Un Ho Jung Wang Lai Yoon 《International Journal of Hydrogen Energy》2014
Low temperature water–gas shift (WGS) reaction has been carried out at the gas hourly space velocity of 72,152 h−1 over Cu–CeO2 catalyst prepared by a co-precipitation method. Cu loading was optimized to obtain highly active co-precipitated Cu–CeO2 catalysts for low temperature WGS. 80 wt% Cu–CeO2 exhibited the highest CO conversion as well as the most stable activity (XCO > 46% at 240 °C for 100 h). The excellent catalytic performance is mainly due to a strong metal to support interaction, resulting in the prevention of Cu sintering. 相似文献
996.
Issei Fujimoto Nini Wang Rie Saito Yugo Miseki Takahiro Gunji Kazuhiro Sayama 《International Journal of Hydrogen Energy》2014
We report on the improvement in the water splitting efficiency of a WO3/BiVO4 composite photoelectrode by the application of an improved auto-combustion method to the preparation of porous BiVO4 thin films. The unique feature of this preparation method is the addition of both NH4NO3, as a strong oxidizing agent, and an organic additive into BiVO4 precursor solution. The local decomposition heat of the organic additive and oxidizing agent created a porous film with small, highly crystalline BiVO4 particles. The photoelectrode has many advantages over existing ones, such as the high light-harvesting efficiency (LHE), a single BiVO4 phase, the facile access of the holes to the photoelectrode/electrolyte interface, and the ease of water and oxygen diffusion. The maximum incident photon-to-current efficiency (IPCE) was estimated to be 64% (at 440 nm, 1.23 V vs. RHE) and the applied bias photon-tocurrent efficiency (ABPE) reached as high as 1.28%. This ABPE value is highest among all oxide semiconductor photoelectrodes reported previously, except for the case of a stacking photoelectrode system. 相似文献
997.
The effect of transition metal ions(M~(2+)=Mn~(2+),Ni~(2+),Co~(2+),Cu~(2+)) on the chemical synthesis of polyaniline(PANI) used as a platinum-free counter electrode(CE) in dye-sensitized solar cells(DSSCs) was investigated.PANI was synthesized by co-polymerization of aniline in the presence of different transition metal ions by using potassium dichromate in acidic medium. It was found that the ion doping of PANI showed a certain catalytic activity for the regeneration of traditional iodide/triiodide(I~-/I_3~-) redox couples. The power conversion efficiency(η) of PANI CEs doped with Mn~(2+),Ni~(2+),Co~(2+) (4.41%, 2.36% and 2.10%, respectively) were higher than 1.94%, the value measured for PANI CE without doping. Doping with Cu~(2+)decreased the power conversion efficiency of PANI CE(PANI-Cu~(2+) η = 1.41%). The electrical properties of the PANI, PANI-Ni~(2+), PANI-Co~(2+),PANI-Mn~(2+) and PANI-Cu~(2+) were studied by cyclic voltammetry(CV), impedance(EIS), and Tafel polarization curve. The experimental results confirmed that PANI was affected by the doping of different transition metal ions(M~(2+)=Mn~(2+),Ni~(2+),Co~(2+),Cu~(2+)). These results indicate a potential application of ion doped PANI as counter electrode in cost-effective DSSCs. 相似文献
998.
999.
This paper presents a combined experimental and numerical study of the properties of a liquid metal flow inside a cylinder driven by the application of a strong electrical current. The interaction between the electric current running through the melt and the corresponding induced magnetic field produces so-called electro-vortex flows. We consider here a configuration of two parallel pencil electrodes immersed at the free surface. Velocity measurements were performed by means of the Ultrasound Doppler method. A linear array of 25 singular transducers was used to determine the two-dimensional pattern of the vertical flow component. Numerical simulations of the magnetohydrodynamic (MHD) problem were conducted to calculate the Lorentz force, the Joule heating and the induced melt flow. Experimental and numerical results reveal a complex three-dimensional flow structure of the liquid metal flow. In particular, two pronounced downward jets are formed below both electrodes. The flow structure appears to be symmetrical with respect to two vertical cross sections being perpendicular to each other and one of the two planes contains the electrodes. The comparison between the experimental data and the numerical results shows a very good agreement. 相似文献
1000.