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1.
接近室温的更高工作温度是第三代红外探测器发展的重要方向。本文论述了用MBE在InSb(100)衬底上外延生长制备P-i-N型三元In1-xAlxSb薄膜合金材料,并通过制备单元器件进行了验证。采用RHEED振荡和X射线双晶衍射对In1-xAlxSb薄膜的Al组分进行了调控和检测。5.3 μm厚薄膜的FWHM≈50 arcsec,Al组分约1.9%。10 μm×10 μm原子力表面粗糙度RMS≈0.6 nm。制备的单元器件获得了预期的理想效果,为下一步面阵焦平面的制备奠定了基础。 相似文献
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应对第三代红外焦平面技术挑战的HgCdTe分子束外延 总被引:1,自引:0,他引:1
叙述了围绕第三代红外焦平面的需求所进行的HgCdTe分子束外延的一些研究结果.75mm HgCdTe薄膜材料的组分均匀性良好,80K下截止波长偏差为0.1μm.对所观察到的HgCdTe表面缺陷成核机制进行了分析讨论,获得的75mm HgCdTe材料平均表面缺陷密度低于300cm-2.研究发现As的表面黏附系数很低,对生长温度十分敏感,在170℃下约为1×10-4.计算表明,As在HgCdTe中的激活能为19.5meV,且随(Na∑Nd)1/3的增大呈线性下降关系,反比系数为3.1×10-5meV·cm.实验发现Hg饱和蒸汽压下,对应不同的温度240,380,440℃,As在HgCdTe中的扩散系数分别为(1.0±0.9)×10-16,(8±3)×10-15,(1.5±0.9)×10-13cm2/s.采用分子束外延生长的HgCdTe材料已用于红外焦平面探测器件的研制,文中报道了一些初步结果. 相似文献
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Ning Zhuo Feng Qi Liu Jin Chuan Zhang Li Jun Wang Jun Qi Liu Shen Qiang Zhai Zhan Guo Wang 《Nanoscale research letters》2014,9(1):144
We demonstrated an unambiguous quantum dot cascade laser based on InGaAs/GaAs/InAs/InAlAs heterostructure by making use of self-assembled quantum dots in the Stranski-Krastanow growth mode and two-step strain compensation active region design. The prototype generates stimulated emission at λ ~ 6.15 μm and a broad electroluminescence band with full width at half maximum over 3 μm. The characteristic temperature for the threshold current density within the temperature range of 82 to 162 K is up to 400 K. Moreover, our materials show the strong perpendicular mid-infrared response at about 1,900 cm-1. These results are very promising for extending the present laser concept to terahertz quantum cascade laser, which would lead to room temperature operation.
PACS
42.55.Px; 78.55.Cr; 78.67.Hc 相似文献5.
Felix Schubert Steffen Wirth Friederike Zimmermann Johannes Heitmann Thomas Mikolajick 《Science and Technology of Advanced Materials》2016,17(1):239-243
Growth conditions have a tremendous impact on the unintentional background impurity concentration in gallium nitride (GaN) synthesized by molecular beam epitaxy and its resulting chemical and physical properties. In particular for oxygen identified as the dominant background impurity we demonstrate that under optimized growth stoichiometry the growth temperature is the key parameter to control its incorporation and that an increase by 55?°C leads to an oxygen reduction by one order of magnitude. Quantitatively this reduction and the resulting optical and electrical properties are analyzed by secondary ion mass spectroscopy, photoluminescence, capacitance versus voltage measurements, low temperature magneto-transport and parasitic current paths in lateral transistor test structures based on two-dimensional electron gases. At a growth temperature of 665?°C the residual charge carrier concentration is decreased to below 1015 cm?3, resulting in insulating behavior and thus making the material suitable for beyond state-of-the-art device applications. 相似文献
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A practical computing algorithm has been developed for calculating the reflection high-energy electron diffraction (RHEED) from the molecular beam epitaxy growing surface. The calculations are based on the use of the dynamical diffraction theory in which the electrons are taken to be diffracted by a potential, which is periodic in the dimension perpendicular to the surface. The computer program presented in this paper enables calculations for three basic types of diffuse potential for crystalline heteroepitaxial structures, including the possible existence of various diffuse scattering models through the layer parallel to the surface. 相似文献
7.
Na-H in-situ codoping in single crystalline ZnO films was carried out by plasma assisted molecular beam epitaxy. It is found that Na-H codoping dramatically enhances the formation of substitutional Na (NaZn) in ZnO lattice due to the unchanged Fermi level. The annealing temperature needed to kick out H, however, is very high, which would concurrently result in a notable decrease of Na concentration to its solution limit in ZnO, namely, in the range of 1017 cm−3. Our results suggest that Na-H codoping method has a limited effect on enhancing the p-type conductivity of ZnO. 相似文献
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M. El Kazzi D.J. WebbL. Czornomaz C. RosselC. Gerl M. RichterM. Sousa D. CaimiH. Siegwart J. FompeyrineC. Marchiori 《Microelectronic Engineering》2011,88(7):1066-1069
Experiments to increase the specific capacitance of MOS capacitors consisting of HfO2 on a passivating interfacial layer (IL) of amorphous Si (a-Si) on GaAs are described. XPS analysis of the layers and electrical measurements on the capacitors are combined to study the evolution of the gate stack during deposition and subsequent heat treatments. It is shown that oxidation of the a-Si IL is a major factor in preventing the attainment of a scaled capacitance equivalent thickness (CET). By controlling the deposition of the layers, the gate metal and the heat treatments, a highly scaled gate stack with a CET of 1.2 nm and a leakage reduction of more than 4 orders of magnitude with respect to SiO2/Si was realized. 相似文献
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