共查询到20条相似文献,搜索用时 62 毫秒
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从物理机制上分析了超高速InP/InGaAs SHBT碰撞电离与温度的关系,通过加入表示温度的参数和简化电场计算,得到一种改进的碰撞电离模型. 同时针对自有工艺和器件特性,采用SDD (symbolically defined device)技术建立了一个包括碰撞电离和自热效应的InP/InGaAs SHBT的直流模型. 模型内嵌入HP-ADS中仿真并与测试结果进行比较,准确地拟合了InP/InGaAs SHBT的器件特性. 相似文献
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在等离子体增强化学气相淀积(PECVD)系统中,采用等离子体氧化和等离子体氮化的方法,在单晶硅表面上成功制备厚度小于10nm的超薄硅基介质膜。通过X射线光电子谱(XPS)分析了超薄介质膜的化学结构,利用椭圆偏振仪测量了厚度以及折射率,同时对超薄介质膜进行了电容电压(C-V)和电流电压(I-V)特性的测量,研究其电学性质,探讨了C-V测量模式对超薄介质膜性质表征的影响,最后对两种介质膜的优缺点进行了比较。 相似文献
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利用磁控溅射方法制备了纳米Co/Cu多层膜。利用扫描探针显微镜(SPM)观测了其表面形貌和磁畴结构,并通过振动样品磁强计(VSM)测量了磁性。结果表明,薄膜的微结构和磁性随非磁性层厚度的变化有着非常显著的变化。超细Co颗粒构造的多层膜样品,颗粒尺寸逐渐增大,磁畴尺寸先减小后增大,最后发生明显的聚集。磁性金属和非磁性金属的比例对多层膜之间的交换耦合相互作用有显著影响。平行膜面方向上的饱和场明显小于垂直膜面方向。当体积比约为1∶80时,平行膜面方向饱和场为95.9 kA/m,垂直方向饱和场为328.1 kA/m。此时两个方向上的饱和场、剩磁、矫顽力和磁滞损耗均为最小值。 相似文献
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Dynamic Analysis of a High-Speed Train 总被引:2,自引:0,他引:2
Studies in modern high-speed traction need to develop detailed equations to formulate a complete electromechanical model that represents the dynamic coupling of electrical and mechanical phenomena. Starting from Lagrange and Park theories, and after recalling the general criteria for the setup of the two distinct mechanical and electrical subsystems, the new formalization of a complete dynamic model with specific reference to a train dedicated to high-speed services is hereby presented. Simulations are carried out with relation to two conditions of particular interest in the application side, i.e., the steady-state condition and the three-phase short-circuit fault at a speed of 100 km/h. Representative of the dynamics of each single component, the investigation in particular focuses on the transmission organs (rotor, Cardan joint, and gear case) and the relevant torques associated with the short-circuit dynamics. 相似文献
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从技术的角度,对有线电视网络上的一种增值业务一高速多媒体数据广播从内容、业务、运营各方面进行了介绍分析,最后简单介绍了太原有线电视网络中心开展数据广播业务的情况, 相似文献
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Jitendra S. Rathore Leonard V. Interrante Geraud Dubois 《Advanced functional materials》2008,18(24):4022-4028
Dense and porous hyperbranched carbosiloxane thin films (HBCSO) are obtained by sol–gel processing using methylene‐bridged hyperbranched polycarbosilanes (HBPCSs) with the general compositional formula {(OMe)2Si(CH2)}. Introduction of porosity is achieved using a porogen templating approach, allowing the control of the films' dielectric constant from 2.9 to as low as 1.8. Over the entire dielectric range, the HBCSO films exhibit exceptional mechanical properties, 2–3 times superior to those obtained for non‐alkylene bridged organosiloxanes such as methylsilsesquioxanes (MSSQs) of similar densities and k‐values. 相似文献
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综述了硅基锗硅薄膜的外延生长技术、设备及其在光电子器件上的应用,其中着重介绍了超高真空化学气相沉积系统(UHVCVD)。目前来说,UHVCVD是产业化制备高质量锗硅材料的最佳选择。 相似文献
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在超高清的技术参数中,HDR是其中尤其重要的组成部分,它提供了更多的画面细节和层次,能够同时展现极亮和极暗的亮度范围,提供更好的“沉浸感”;可在不同亮度级上提供更好的局部对比度,提升边缘锐度;搭配宽色域的扩展,可以提供丰富的色彩数量和更鲜亮的颜色. 相似文献
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Chun-Chieh Lin Chih-Yang Lin Meng-Han Lin Chen-Hsi Lin Tseung-Yuen Tseng 《Electron Devices, IEEE Transactions on》2007,54(12):3146-3151
In this paper, nonpolar resistive switching behavior is reported for the first time in a SZO-based memory device. The electrode materials used which have different conductivities affect the resistive switching properties of the device. The Al/V:SZO-LNO/Pt device shows nonpolar switching behavior, whereas the Al/V:SZO/LNO device has bipolar switching property. The resistance ratios of these two devices are quite distinct owing to the difference between the resistance of low resistance states. The Al/V:SZO-LNO/Pt device with lower resistive switching voltages (mnplus7 V turn on and mnplus2 V turn off) and higher resistance ratio is more suitable for practical applications compared to the Al/V:SZO/LNO device. The switching speed of the Al/V:SZO-LNO/Pt device is 10 ns, which is the fastest speed that has ever been reported. The conduction mechanisms, nondestructive readout property, retention time, and endurance of this device are also reported in this paper. 相似文献
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Crowell J. M. Hiebert R. D. Salzman G. C. Price B. J. Cram L. S. Mullaney P. F. 《IEEE transactions on bio-medical engineering》1978,(6):519-526
A flow-system instrument is described in which the light scattered by a biological cell is detected simultaneously at 32 angles in the forward direction as the cell passes through a focused laser beam at 10 m/s. Cluster analysis is applied to the scatter pattern data to enable discrimination among cell types. 相似文献
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《Microwave Theory and Techniques》1984,32(1):5-10
A source-coupled FET logic (SCFL) circuit is proposed for gigabit rate digital signaf processing. FET threshold voltage tolerance in the SCFL circuit and the SCFL circnit performance are presented. The speed of the SCFL gate depends on the operating region of the FET. For high-speed operation, FET's drain-to-source voltage fdgher than a pinchoff voltage has to be suppfied. The SCFL gate, which is composed of 1.5-pm gate-length FET's, showsthat the minimum propagation time is predicted to be 25 ps/gate. Mhimum rise time and fall time are expected to be S4 ps and 51 ps, respectively. Maximum RZ data rate is expected to be 5.6 Gb/s. The SCFL circnit is applicablefor high-speed dlgitaf sigmd processing. 相似文献