Effect of 80 MeV Au ions irradiation on CuInTe2 single crystals grown by CVT technique

Single crystals of CuInTe₂ (CIT) have been grown by the chemical vapor transport (CVT) technique using iodine as the transporting agent. CIT crystals were irradiated with 80 MeV Au⁸⁺ ions at room temperature at different fluences. The surface roughness was measured using an atomic force microscope (AFM). It was found to increase from 9.319 nm in the as-grown sample to 61.169 nm in the sample irradiated with a fluence of 1×10¹³ ions/cm². The intensities of the X-ray diffraction peaks corresponding to the (112) and (004/200) planes of the irradiated sample decrease with respect to the fluences. The full-width at half-maximum (FWHM) of X-ray rocking curves was measured as a function of different ion fluences. The FWHW increases with increase of ions fluences. This is attributed to the irradiation-induced partial amorphization of the top surface of the CIT crystals. The fall in absorption coefficients with photon energy is sharper for as-grown samples than irradiated samples. The band gap value gradually decreases from 1.04 to 0.977 eV upon Au⁸⁺ ions’ irradiation with a fluence of 1×10¹³ ions/cm². Photoluminescence (PL) measurements show a red shift compared to the as-grown CIT single crystals. The Raman modes of A₁ (high) and E and/or B₂ (LO) are observed at 123 and 173 cm⁻¹ in as-grown CIT single crystals, respectively. As the ion fluence is increased, the Raman frequency increases and the curves broaden. The above observed features are related to the large electronic energy transfer of the Au beam to the CIT crystals.     

地球站射频系统的基本原理及技术指标

根据广播电视卫星地球站的射频铁路，介绍机房内射频系统的基本原理及技术指标，使读者对地球站的上行链路有一定的了解。     

小型电台转播车的设计实践与思考

广播转播车是一个综合的广播业务技术系统,设计制作涉及到车型选择、车身布置、设备选择、供配电以及数字化播出系统的衔接等功能实现方法。详细介绍了珠海广播电视台广播转播车的设计实践。     

一种带曲率补偿的高精度带隙电压基准源

本文提出了一种带运放失调电压补偿结构和分压式二阶曲率补偿结构的低温度系数带隙基准电路。设计目标为对便携设备提供0.8V的电压。基于华虹CZ6H工艺在CADENCE软件TT模型下仿真,仿真结果表明,带隙基准电压源在-40℃-120℃温度范围内温度系数仅为1.77×10-6/℃,电源抑制比(PRSS)在低频下为86.9dB。在3V-6V的电源电压工作范围内,输出电压摆幅为0.171mV。     

Temperature dependence of the linewidth of the first-order Raman spectra for MnF2 crystal

The first-order Raman spectra ofE _gandA _1g modes in MnF₂ crystal were measured at temperatures from 4.2 to 563 K, and the values of the linewidths obtained. The temperature dependence of the linewidths was analyzed by the phonon dispersion curves based on the rigid ion model, and the result showed that it was caused approximately by the cubic anharmonic term in crystal potential energy.     

A Fast and Accurate Method of Redesigning Analog Subcircuits for Technology Scaling

In this paper, we present an efficient approach for technology scaling of MOS analog circuits by using circuit optimization techniques. Our new method is based on matching equivalent circuit parameters between a previously designed circuit and the circuit undergoing redesign. This method has been applied to a MOS operational amplifier. We were able to produce a redesigned circuit with almost the same performance in under 4 h, making this method 5 times more efficient than conventional methods.     

SH320大闭塞量低噪声视频放大器

本文介绍了ＳＨ３２０大闭塞量低噪声视频放大器的设计和研制。从对主要技术指标的分析入手，确定了合理的方案，并对电路进行了优化设计。在制作上，根据性能和结构要求，采用了高密度布线、多芯片组装的薄膜工艺。最后实现的是一种ＭＣＭ（多芯片组件）电路，在电性能上优于用户的要求，在工艺实现上也是采用ＭＣＭ技术的有益尝试。     

电流反馈运算放大器电路与性能综述

电流反馈型运算放大器开拓了一种与双极互补工艺相结合的精巧电路拓扑结构，具有极佳的动态特性。该电路是８０年代末期模拟集成电路新进展的研究成果之一，有较高实用价值和一定理论价值。文章全面剖析了电流反馈运算放大器的拓扑结构特点和电路工作机理，综述了其性能特点、应用领域及相关研究课题。     

江西信丰恐龙蛋化石碎片的显微喇曼光谱研究

本文分别采取两种激光波长激发(514.5nm和785nm),首次利用激光显微喇曼光谱对江西信丰的恐龙蛋化石碎片进行了研究。我们发现恐龙蛋化石的主要矿物成分是方解石。其次,某些样品中还含有少量的石英、α-石英和赤铁矿,其中石英晶体仅分布于蛋壳内表面。显微镜下观察到蛋壳内表面呈黑色的原生方解石以及银白色的次生方解石颗粒,另外,还观测到石英晶体颗粒。近红外激光激发下的喇曼光谱中出现了一些有机物的谱峰,它们分别位于1200cm-1、1300cm-1,和1500cm-1附近。该研究结果为揭示恐龙蛋石化过程中经历的地质环境提供了重要的依据。