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101.
本文描述一种基于8031单片机和TC8830AF语音处理器的PC机智能语音卡,通过软硬件设计解决了PC-8031-TC8830AF结构中的通讯问题。该语音卡在进行语音的合成、编辑和播放时,仅占用极少的PC机CPU处理时间,能满足计算机系统进行实时语音合成的要求。 相似文献
102.
Uhm H.S. Lee P.H. Kim Y.I. Kim J.H. Chang H.Y. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1995,23(4):628-635
A theory is developed for the density profile of low temperature plasmas confined by applied magnetic field and an experiment of the electron-cyclotron-resonance (ECR) plasma is conducted to compare the theoretical prediction and experimental measurements. Due to a large electron mobility along the magnetic field, electrons move quickly out of the system, leaving ions behind and building a space charge potential, which leads to the ambipolar diffusion of ions. In a steady-state condition, the plasma generation by ionization of neutral molecules is in balance with plasma loss due to the diffusion, leading to the electron temperature equation, which is expressed in terms of the plasma size, chamber pressure, and the ionization energy and cross section of neutrals. The power balance condition leads to the plasma density equation, which is also expressed in terms of the electron temperature, the input microwave power and the chamber pressure. It is shown that the plasma density increases, reaches its peak and decreases, as the chamber pressure increases from a small value (0.1 mTorr). These simple expressions of electron temperature and density provide a scaling law of ECR plasma in terms of system parameters. After carrying out an experimental observation, it is concluded that the theoretical predictions of the electron temperature and plasma density agree remarkably well with experimental data 相似文献
103.
Zhengmao Ye Campbell J.C. Zhonghui Chen Eui-Tae Kim Madhukar A. 《Quantum Electronics, IEEE Journal of》2002,38(9):1234-1237
An InAs/AlGaAs quantum-dot infrared photodetector based on bound-to-bound intraband transitions in undoped InAs quantum dots is reported. AlGaAs blocking layers were employed to achieve low dark current. The photoresponse peaked at 6.2 /spl mu/m. At 77 K and -0.7 V bias, the responsivity was 14 mA/W and the detectivity, D*, was 10/sup 10/ cm/spl middot/Hz/sup 1/2//W. 相似文献
104.
Taesung Kim Sung Ho Wang Beomsup Kim 《Electronics letters》2002,38(17):950-951
A delay-locked loop (DLL) architecture capable of incorporating fast locking and low jitter features simultaneously is reported. A test chip was fabricated in a 0.6 μm CMOS process to prove its functionality. The proposed DLL can align the internal clock to the external reference clock within two cycles and maintain its locking state with the aid of feedback operation 相似文献
105.
106.
We predict that, for wavelength division multiplexing optical-network applications, an asymmetrically dilated configuration of a 2×2 cross-connect is significantly better in terms of overall crosstalk when the levels of the bar-port crosstalk and the cross-port crosstalk are significantly different from each other, as is the case with optical-frequency filters which utilize grating-assisted coupling. As a verification, we present a simulation study with 2×2 polarization-diversified acousto-optic tunable filters. We present a recursive method to extend the principle of asymmetric dilation to larger-size cross-connect switches, and make a recommendation for an asymmetrically dilated 4×4 cross-connect configuration 相似文献
107.
108.
本文论述了具有透明波导结构的量子阱半导体激光器及其光集成技术的其本原理及主要优点。尤其在实现高功率窄光束输出的光集成器件方面更显出其独特的优点。 相似文献
109.
Ki Hyun Kim Yong Hoon Kang Byoungho Lee 《Photonics Technology Letters, IEEE》1997,9(12):1610-1612
A photorefractive volume hologram was recorded and probed using light diffracted from a tapered optical fiber as a reference beam. A single-mode fiber (SMF) was chemically etched and tapered to give a complicated beam pattern, and it is shown that the tapered optical fiber can be utilized to increase the storage density of the volume hologram. Spatial selectivity of the volume hologram with this method was increased by two times compared to the normal SMF referencing, which is due to the fact that the complicated beam pattern has little correlation with its shifted version 相似文献
110.
制作压力传感器时,在二氧化硅层上淀积多晶硅膜,既可利用优良的机械特性,又可保证压敏电阻与衬底间具有良好的绝缘性,由此可大大提高器件的温度特性。介绍了一种多晶硅压力传感器的原理和设计。实验结果表明,这类传感器具有灵敏度好,精度高等特点,电路工作范围为0-250℃,且具有良好的温度稳定性。 相似文献