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71.
Strain evolutions of SiGe film during Ge condensation processes of SiGe on silicon-on-insulator were studied in detail with assistance of X-ray diffraction. At the beginning of Ge condensation, SiGe on silicon-on-insulator with low Ge fraction was oxidized at higher temperature of 1150 °C, the strong plastic deformation of buried SiO2 and Si-Ge intermixing relieved most of the strain in SiGe with increasing Ge fraction. When temperature was reduced to 900 °C for oxidation of SiGe layer with higher Ge fraction, Ge accumulation overmatched Si-Ge inter-diffusion, resulting in non-uniform profile of Ge in SiGe layer. During this period, plastic deformation of buried SiO2 can be neglected and dislocation gliding plays a significant role in relieving strain in SiGe, which enlarges the surface roughness. The strain in SiGe increases gradually with condensation time for the thickness of SiGe layer reduces close to its critical thickness, even with higher Ge fraction. Intensive over-oxidation of germanium-on-insulator materials was suggested to be effective to fully relax the compressive strain but should be precisely controlled to avoid surface deterioration. 相似文献
72.
Ki Yeol Byun Isabelle FerainJohn Hayes Ran Yu Farzan Gity Cindy Colinge 《Microelectronic Engineering》2011,88(4):522-525
In this work, an alternative method for producing the single crystalline Ge-Si Avalanche photodiodes (APD) with low thermal budget was investigated. Structural and electrical investigations show that low temperature Ge to Si wafer bonding can be used to achieve successful APD integration. Based on the surface chemistry of the Ge layer, the buried interfaces were investigated using high resolution transmission electron microscopy as a function of surface activation after low temperature annealing at 200 and 300 °C. The hetero-interface was characterized by measuring forward and reverse currents. 相似文献
73.
D. Tsoutsou Y. PanayiotatosS. Galata A. SotiropoulosG. Mavrou E. GoliasA. Dimoulas 《Microelectronic Engineering》2011,88(4):407-410
The molecular and atomic oxidation of molecular beam deposited Se passivating layers on Ge substrates was in situ investigated by X-ray photoelectron spectroscopy. It turns out that while Se is efficient in suppressing Ge oxidation upon molecular oxygen exposure, an extra thin Al layer is needed to protect the Ge surface from highly reactive atomic oxygen radicals. Electrical measurements performed on the Al-covered surfaces reveal that Se is beneficial in reducing the interface state density. 相似文献
74.
The change of strain in Si0.7Ge0.3 films was investigated with medium energy ion scattering (MEIS). Si was removed in the films by selective oxidation at 800 °C, resulting in the formation of a Ge pile-up layer on the surface. The relaxation and the thickness of the pile-up layer were closely related to the oxidation time. MEIS data demonstrated that relaxation of the Ge layer in the depth direction occurred partially, and that the rates of relaxation decreased with depth. In addition, the rate of relaxation increased with the oxidation time. Lastly, the relaxation of the Ge layer affected the strain of the remaining Si0.7Ge0.3 substrate. 相似文献
75.
徐国焱 《湖南工业职业技术学院学报》2010,10(1):78-79
在魏晋南北朝时期,道教神学理论进入了繁忙建设阶段。葛洪作为道教神学理论的奠基人,《抱朴子内篇》是其经典作品。在通过对神仙的有无,成仙的途径手段两个方面作出了创造性的阐述,从而在确立了神仙必有、长生可致的完整体系。 相似文献
76.
本文介绍了一种直接扣除峰下本底的技术,这个技术已在《SPAN Ge(Li)γ谱分析程序》中得到成功的应用。这个方法是积分峰本底技术的完善和发展,它对于十分复杂的包含有多重峰的Ge(Li)γ谱也能得出合理的本底线,并且能从γ谱中直接扣除。 相似文献
77.
R. Tyagi M. Bal M. Singh Satish Mohan T. Haldar A. Naik Premveer Singh M. Husain S. K. Agarwal 《Solar Energy Materials & Solar Cells》2003,76(3):257-261
Hydrogen passivation on MOCVD grown p-GaAs epilayers on Ge substrate have been studied by plasma and catalytic hydrogenation and the results were compared. The conversion efficiency of the GaAs/Ge solar cells was found to increase by 10% after catalytic hydrogenation at AM1.5. This increase in efficiency is probably due to passivation of surface dangling bonds. 相似文献
78.
79.
A. V. Morozkin 《Journal of Alloys and Compounds》2004,370(1-2):L1-L3
Phase equilibria in the Ce–Ti–Ge system were investigated by X-ray powder diffraction, electron probe X-ray analysis and the isothermal section at 1170 K was obtained. We confirmed the CeFeSi-type CeTiGe compound (a=0.4135 (1) nm, c=0.7921 (1) nm, space group P4/nmm, No. 129). A new compound, Ce20Ti20Ge60, was found (a=0.3967(6) nm, c=6.054 (2) nm, space group P4). It is obvious that the ThSi2-type Ce33Ti7Ge54 compound (a=0.4217 (1) nm, c=1.4184 (3) nm, space group I41/amd, No. 141) belongs to the extended solid solution region of the ThSi2-type CeGe2 compound. 相似文献
80.
微型反应堆辐照座内中子温度和超热指标的测定 总被引:4,自引:4,他引:0
一、引言对于高浓铀燃料、金属铍反射层,主要作为中子活化分析用的微型反应堆而言,对有关辐照座内的能谱和谱参数必须有所了解,中子温度是重要的谱参数,它基本上反映了反应堆热谱的特征。 相似文献