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101.
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103.
LEUNG Shu-hung 《中国邮电高校学报(英文版)》2006,13(2):84-102
1Introduction OFDMisconsideredasoneofthekeytechnologiesfor nextgenerationwirelesscommunicationsbecauseofits abilitytoefficientlycombatInter SymbolInterference(ISI)anditsgoodimmunitytomultipathfading.Also itcanconvertafrequency selectivefadingchannelinto s… 相似文献
104.
For group III-nitrides with wurtzite structure the presence of fixed polarization interface charges yields new challenges in order to understand and control Schottky barrier heights, band offsets and 2D confinement in heterostructure FETs. In this short review experimental results obtained by in situ photoemission spectroscopy on MBE AlGaN/GaN heterostructures grown on 6H–SiC are discussed, with emphasis on the presence and interplay of surface electronic states. Schrödinger–Poisson calculations are performed to get the complete band scheme at the selected heterojunctions. Results on the polarity dependence of Pt/GaN Schottky barrier values from the literature are also discussed. 相似文献
105.
Massimo Conti Paolo Crippa Simone Orcioni Marcello Pesare Claudio Turchetti Loris Vendrame Silvia Lucherini 《Analog Integrated Circuits and Signal Processing》2003,37(2):85-102
In this paper a novel CAD methodology for yield enhancement of VLSI CMOS circuits including random device variations is presented. The methodology is based on a preliminary characterization of the technological process by means of specific test chips for accurate mismatch modeling. To this purpose, a very accurate position-dependent parameter mismatch model has been formulated and extracted. Finally a CAD tool implementing this model has been developed. The tool is fully integrated in an environment of existing commercial tools and it has been experimented in the STMicroelectronics Flash Memory CAD Group.As an example of application, a bandgap reference circuit has been considered and the results obtained from simulations have been compared with experimental data. Furthermore, the methodology has been applied to the read path of a complex Flash Memory produced by STMicroelectronics, consisting of about 16,000 MOSFETs. Measurements of electrical performances have confirmed the validity of the methodology, and the accuracy of both the mismatch model and the simulation flow. 相似文献
106.
双轴晶体主平面上倍频的相位匹配参量 总被引:1,自引:0,他引:1
根据折射率椭球方程及双光轴晶体中光波的传播与偏振特性,分析双轴晶体在主平面内激光倍频相位匹配的特性与方法,导出光波在主平面上传播时倍频的相位失配关系;给出双轴晶体中容许相位匹配倍频的相位匹配角及混频的有效非线性系数deff的表达式。利用可相位匹配的类型、相位匹配角公式和有效非线性系数deff表达式的表,容易对任意一具体晶体在一给定波长求出实际能实现相位匹配的类型或偏振组合,算出相位匹配角,比较不同的相位匹配类型或偏振组合的有效非线性系数,选择最佳的相位匹配类型与方向。从相位失配关系可以计算晶体主平面内倍频的接收角、接收光谱宽度等特性参量。 相似文献
107.
108.
S. P. Ahrenkiel M. W. Wanlass J. J. Carapella L. M. Gedvilas B. M. Keyes R. K. Ahrenkiel H. R. Moutinho 《Journal of Electronic Materials》2004,33(3):185-193
Low-bandgap, lattice-mismatched GaxIn1−xAs (GaInAs) grown using InAsyP1−y (InAsP) compositional-step grades on InP is a primary choice for lightabsorbing, active layers in high-efficiency thermophotovoltaic
(TPV) devices. The GaInAs/InAsP double heterostructures (DHs) show exceptional minority carrier lifetimes of up to several
microseconds. We have performed a characterization survey of 0.4–0.6-eV GaInAs/InAsP DHs using a variety of techniques, including
transmission electron microscopy (TEM). Dislocations are rarely observed to thread into the GaInAs active layers from the
InAsP buffer layers that terminate the graded regions. Nearly complete strain relaxation occurs in buried regions of the InAsP
grades. The buffer-layer strain prior to deposition of the active layer is virtually independent of the net misfit. Foreknowledge
of this buffer-layer strain is essential to correctly lattice match the buffer to the GaInAs active layer. 相似文献
109.
Su Weimin Gu Hong Ni Jinlin Liu Guosui Zhang Guangyi 《电子科学学刊(英文版)》1998,15(3):226-232
This paper presents the performance analysis of the MUSIC algorithm in the presence of channel amplitude and phase Error. Theoretical expression for the error of DOA estimating with MUSIC algorithm and Cramer-Rao bound are derived. It is compared with simulations performed for some representative cases. The results of theoretical expression and simulation show that existence of these errors will increase the error of DOA estimating and degrade its performance. 相似文献
110.
在GaSb衬底上用LPE法生长了晶格匹配的AlGaAsSb外延层。用室温光致发光和X射线双晶衍射分别测量了材料的禁带宽度和晶格常数,并与用内插法计算的结果进行了比较。用C-V和van der Pauw法测量了样品的电学参数。用激光喇曼散射和低温光致发光研究了材料的光学性质,观察到了类GaSb的LO模和类AlSb的LO模以及LO声子与等离子激元的耦合模L_-;对x=0.2,y=0.025的样品,由低温到室温的变温光致发光测量确定的禁带宽度的温度系数为-3.2×10~(-4)eV/K。此外对于晶格失配,P型的原因以及PL谱峰的展宽等问题进行了讨论。 相似文献