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71.
Deep levels in AlGaN/GaN high electron mobility transistors (HEMTs) on SiC substrate are known to be responsible for trapping processes like: threshold voltage shift, leakage current, degradation current, kink effect and hysteresis effect. The related deep levels are directly characterized by conductance deep level transient spectroscopy (CDLTS) method. Hereby, we have detected five carrier traps with activation energy ranging from 0.84 to 0.07 eV. In this study, we have revealed the presence of two hole-like traps (HL1 and HL2) observed for the first time by CDLTS with activations energy of 0.40 and 0.84 eV. The localisation and the identification of these traps are presented. Finally, the correlation between the anomalies observed on output and defects is discussed. 相似文献
72.
Ⅲ-Ⅴ族GaN基材料以其在紫外光子探测器、发光二极管、高温及大功率电子器件等方面的应用潜能而被广为研究.其中,低阻欧姆接触是提高GaN基器件光电性能的关键.金属/GaN界面上较大的欧姆接触电阻一直是影响器件性能及可靠性的一个问题.对于各种应用来说, GaN的欧姆接触需要得到改进.通过对相关文献的归纳分析,本文主要介绍了近年来在改进n-GaN工艺,提高欧姆接触性能等方面的研究进展. 相似文献
73.
74.
Hareesh Chandrasekar Towhidur Razzak Caiyu Wang Zeltzin Reyes Kausik Majumdar Siddharth Rajan 《Advanced Electronic Materials》2020,6(8)
A negative‐capacitance high electron mobility transistor (NC‐HEMT) with low hysteresis in the subthreshold region is demonstrated in the wide bandgap AlGaN/GaN material system using sputtered BaTiO3 as a “weak” ferroelectric gate in conjunction with a conventional SiNx dielectric. An enhancement in the capacitance for BaTiO3/SiNx gate stacks is observed in comparison to control structures with SiNx gate dielectrics directly indicating the negative capacitance contribution of the ferroelectric BaTiO3 layer. A significant reduction in the minimum subthreshold slope for the NC‐HEMTs is obtained in contrast to standard metal‐insulator‐semiconductor HEMTs with SiNx gate dielectrics—97.1 mV dec−1 versus 145.6 mV dec−1—with almost no hysteresis in the ID–VG transfer curves. These results are promising for the integration of ferroelectric perovskite oxides with III‐Nitride devices toward NC‐field‐effect transistor switches with reduced power consumption. 相似文献
75.
Chujun Yi Yibo Chen Zhe Kang Yanan Ma Yang Yue Weijie Liu Meng Zhu Yihua Gao 《Advanced Electronic Materials》2021,7(5):2000955
Due to their excellent electrical conductivity, high transmittance, and adjustable work function, 2D transition-metal carbides and nitrides have shown great promise in optoelectronic applications, especially in MXene-semiconductor devices. In this work, Ti3 C2TX /(n/p)-GaN van der Waals heterostructures are fabricated and studied. The Ti3 C2TX /(n/p)-GaN Schottky junctions are confirmed by ultraviolet photoelectron spectroscopy (UPS) with a work function ≈4.2 eV of Ti3 C2TX . Based on the Ti3 C2TX /(n/p)-GaN Schottky junctions, high-speed photodetectors and stable orange light emitting diodes (LEDs) are fabricated. The Ti3 C2TX /n-GaN heterostructure photodetector shows a short rise time (60 ms) and decay time (20 ms), a high responsivity (44.3 mA W−1) and on/off ratio (≈11300) under a light source of 365 nm wavelength and 96.9 µW cm−2 power density. And the Ti3 C2TX /p-GaN heterostructure LED remains a stable orange light emission under bias voltage from 4 to 22 V. The chromaticity coordinates and color temperature of EL spectrum under 22 V are further calculated to be 0.4541, 0.4432, and 2953 K, respectively. The authors believe that this work provides fundamental insight into the applications of MXene in optoelectronic devices. 相似文献
76.
François Templier 《Journal of the Society for Information Display》2016,24(11):669-675
High‐brightness GaN‐based emissive microdisplays can be fabricated with different approaches that are listed and described. They consist either of hybridizing a GaN LED array on a CMOS circuit or building a monolithic component on a single substrate. Using the hybridization approach, two types of 10‐μm pixel pitch GaN microdisplay prototypes were developed: (1) directly driven, 300 × 252 pixels and (2) active‐matrix, 873 × 500 pixels. Brightness as high as 1 × 106 and 1 × 107 cd/m2 for blue and green arrays, respectively, were reached. GaN‐based emissive microdisplays are suitable for augmented reality systems or head‐up displays, but some challenges remain before they can be put in production. 相似文献
77.
This article analyzes the bias dependence of gate‐drain capacitance (Cgd) and gate‐source capacitance (Cgs) in the AlGaN/GaN high electron mobility transistors under a high drain‐to‐source voltage (Vds) from the perspective of channel shape variation, and further simplifies Cgd and Cgs to be gate‐to‐source voltage (Vgs) dependent only at high Vds. This method can significantly reduce the number of parameters to be fitted in Cgd and Cgs and therefore lower the difficulty of model development. The Angelov capacitance models are chosen for verifying the effectiveness of simplification. Good agreement between simulated and measured small‐signal S‐parameters, large‐signal power sweep, and power contours comprehensively proves the accuracy of this simplification method. 相似文献
78.
79.
通过高温Hall测量研究了GaN和AlxGa1-xN/GaN异质结从室温到500℃高温下的输运性质.实验发现GaN背景载流子浓度随着温度的升高而升高,载流子浓度变化的幅度和GaN的位错密度存在正比关系,持续光电导的跃迁幅度和GaN的位错密度也存在正比关系,说明位错相关的深施主或者陷阱对GaN在高温下的背景浓度有很大影响.实验发现AlxGa1-xN/GaN异质结中二维电子气的浓度在室温到250℃的范围内随着温度的升高而下降,然后随着温度的升高开始增加.前者主要是由于随着温度的升高,AlxGa1-xN/GaN异质结的导带不连续减小引起的,后者主要是由GaN层背景载流子浓度增加导致的.通过求解自洽的薛定谔和泊松方程得到的二维电子气浓度的温度关系和实验结果一致. 相似文献
80.