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61.
Experimental verification of a low temperature (<20 °C), reactive plasma etch process for copper films is presented. The plasma etch process, proposed previously from a thermochemical analysis of the Cu-Cl-H system, is executed in two steps. In the first step, copper films are exposed to a Cl2 plasma to preferentially form CuCl2, which is volatilized as Cu3Cl3 by exposure to a H2 plasma in the second step. Plasma etching of thin films (9 nm) and thicker films (400 nm) of copper has been performed; chemical composition of sample surfaces before and after etching has been determined by X-ray photoelectron and flame atomic absorption spectroscopies. 相似文献
62.
63.
In this work, undoped and Zn-doped copper oxide films were deposited on glass substrates at a substrate temperature of 250 ± 5°C
by using an ultrasonic spray pyrolysis technique. Electrical, optical, and structural properties of the films were investigated,
and the effect of Zn incorporation on these properties are presented. The variations of electrical conductivities and electrical
conduction mechanisms of all films were investigated in the dark and in the light. Optical properties of the produced films
were analyzed by transmission, linear absorption coefficient, and reflection spectra. The band gaps of the films were determined
by an optical method. The film structures were studied by x-ray diffraction. To obtain information about structural properties
in detail, the grain size (D), dislocation density (δ), and lattice parameters for preferential orientations were calculated. The elemental analyses were performed using energy-dispersive
x-ray spectroscopy. It was concluded that Zn has a strong effect, especially on the electrical and structural properties,
and the undoped and Zn-doped copper oxide (at 3%) films may be used as absorbing layers in solar cells due to their low resistivities
and suitable linear absorption coefficient values. 相似文献
64.
65.
O. Dubreuil M. Cordeau Th. Mourier P. Chausse D. Bellet 《Microelectronic Engineering》2008,85(10):1988-1991
With the downscaling of feature dimensions, copper interconnects exhibit properties differing from bulk or film material. Resistivity increases and limits electrical performances, and reliability of interconnects becomes a more important challenge for each new technological node. In this study, we present an approach of copper grain growth control inside narrow wires by adding a step between the copper electro-chemical deposition (ECD) and the chemical-mechanical polishing (CMP). This step corresponds to a partial CMP step (pre-CMP) and is applied after ECD and before anneal in order to modify the copper overburden thickness. Depending on the targeted thickness, copper grain growth occurs during anneal with different efficiencies. Crystallization and grain growth behaviour inside wires is investigated with focused ions beam (FIB). We present here our methodology for sample preparation and characterization. Results are focused on electrical variations and on morphological aspects of copper crystallization and grain growth inside lines observed with various overburden thicknesses. 相似文献
66.
The microstructure of Cu interconnections fabricated by high-pressure annealing was evaluated using a field emission scanning
electron microscope/electron backscatter diffraction pattern (FE-SEM/EBSP) technique, and the results are compared with as-deposited
and normally annealed Cu films. The results show some grains extending from the bulk field to the via regions in the case
of the high-pressure annealed Cu films. The existence of via holes was also observed, in which all grains were (111) oriented.
This indicates that the high-pressure annealing process enables the Cu that in-fills the via holes to develop into favorable
microstructures, i.e., single-crystal and with (111) orientation. 相似文献
67.
Kai Xiao Rongjin Li Jing Tao Edward A. Payzant Ilia N. Ivanov Alex A. Puretzky Wenping Hu David B. Geohegan 《Advanced functional materials》2009,19(23):3776-3780
This paper describes a simple, vapor‐phase route for the synthesis of metastable α‐phase copper‐phthalocyanine (CuPc) single‐crystal nanowires through control of the growth temperature. The influence of the growth temperature on the crystal structures, morphology, and size of the CuPc nanostructures is explored using X‐ray diffraction (XRD), optical absorption, and transmission electron microscopy (TEM). α‐CuPc nanowires are successfully incorporated as active semiconductors in field‐effect transistors (FETs). Single nanowire devices exhibit carrier mobilities and current on/off ratios as high as 0.4 cm2 V?1 s?1 and >104, respectively. 相似文献
68.
69.
This paper addresses the effects of substrate temperature on electrical and structural properties of dc magnetron sputter-deposited copper (Cu) thin films on p-type silicon. Copper films of 80 and 500 nm were deposited from Cu target in argon ambient gas pressure of 3.6 mTorr at different substrate temperatures ranging from room temperature to 250 °C. The electrical and structural properties of the Cu films were investigated by four-point probe and atomic force microscopy. Results from our experiment show that the increase in substrate temperature generally promotes the grain growth of the Cu films of both thicknesses. The RMS roughness as well as the lateral feature size increase with the substrate temperature, which is associated with the increase in the grain size. On the other hand, the resistivity for 80 nm Cu film decreases to less than 5 μΩ-cm at the substrate temperature of 100 °C, and further increase in the substrate temperature has not significantly decreased the film resistivity. For the 500 nm Cu films, the increase in the grain size with the substrate temperature does not conform to the film resistivity for these Cu films, which show no significant change over the substrate temperature range. Possible mechanisms of substrate-temperature-dependent microstructure formation of these Cu films are discussed in this paper, which explain the interrelationship of grain growth and film resistivity with elevated substrate temperature. 相似文献
70.
An in-situ polymerization method has been employed to prepare CuO/PANI nanocomposite. The prepared samples have been characterized by X-ray diffraction (XRD), FTIR spectroscopy, field emission scanning electron microscopy (FESEM), and BET analysis. Application of the prepared samples has been evaluated as supercapacitor material in 1 M Na2SO4 solution using cyclic voltammetry (CV) in different potential scan rates, ranging from 5 to 100 mV s−1, and electrochemical impedance spectroscopy (EIS). The specific capacitance of CuO/PANI has been calculated to be as high as 185 F g−1, much higher than that obtained for pure CuO nanoparticles (76 F g−1). Moreover, the composite material has shown better rate capability (75% capacitance retention) in various scan rates in comparison with the pure oxide (30% retention). EIS results show that the composite material benefits from much lower charge transfer resistance, compared to CuO nanoparticles. Moreover, much better cyclic performance has been achieved for the composite material. 相似文献