Growth of aligned single-walled carbon nanotubes under ac electric fields through floating catalyst chemical vapour deposition

Through floating catalyst chemical vapour deposition(CVD) method,well-aligned isolated single-walled carbon nanotubes (SWCNTs) and their bundles were deposited on the metal electrodes patterned on the SiO₂/Si surface under ac electric fields at relatively low temperature(280℃). It was indicated that SWCNTs were effectively aligned under ac electric fields after they had just grown in the furnace.The time for a SWCNT to be aligned in the electric field and the effect of gas flow were estimated. Polarized Raman scattering was performed to characterize the aligned structure of SWCNTs. This method would be very useful for the controlled fabrication and preparation of SWCNTs in practical applications.     

对“一维链状冠醚配合物[K(B18-C-6)]_2[M(SCN)_4](M=Pd,Pt)的合成与结构”一文的更正

我们合成、表征了苯并 1 8 冠 6(B1 8 C 6)与K2 [Pd (SCN) 4 ],K2 [Pt(SCN) 4 ]生成的一维链状配合物 [K(B1 8 C 6) ]2 [Pd(SCN) 4 ]( 1 ) ,[K(B1 8 C 6) ]2 [Pt(SCN) 4 ]( 2 )和[K(B1 8 C 6) ]2 [Pt(SCN) 4 ]·C2 H4Cl2 ( 3 ) .其中 3为三斜晶系 ,空间群P1 [化学学报 2 0 0 2 ,60 ( 8) ,1 465 ].厦门大学胡盛志教授认为该化合物的空间群应为P 1 .经将原始数据重新还原、修正 ,3的空间群的确为P 1 ,现予以更正 .配合物 3部分结构数据由表 1给出 ,其非氢原子坐标和热参数列于表 2 ,部分键长和键角列于表 3 .晶体结构和堆积图…     

基于LabVIEW的运动目标跟踪系统的研究

主要对创新实验室二维视觉跟踪转台的算法进行改进。传统的算法只能实现在白色背景下对黑色目标的识别与跟踪,为实现对不同目标复杂背景的跟踪,针对跟踪系统设备和系统指标要求,确定了图像预处理、图像分割、形心跟踪等算法。针对目标的特点,根据识别的目标用形心跟踪算法进行跟踪。文中所有控制程序都基于LabVIEW,在MFC框架下用C++编写图像处理程序。结果表明,在LabVIEW平台下的识别跟踪过程中,二维转台最终实现良好的控制,使整个系统快速、准确的跟踪运动的特征物体,完成了二维目标视觉检测与跟踪的目的。     

二氧化锡薄膜：制备及在室温下气敏性质

利用溶胶-凝胶法首先在玻璃基片上制备了氧化锡晶种膜,之后采用溶剂热法在其上生长了致密的氧化锡薄膜。利用扫描电子显微镜和X射线衍射技术对氧化锡薄膜的形貌和晶体结构进行了表征,结果表明构成薄膜的氧化锡晶粒具有四方锡石结构,尺寸在7~10nm之间。表面活性剂在溶剂热反应过程中对薄膜生长的研究表明,十二烷基苯磺酸钠可以显著提高薄膜的质量。对所制备的氧化锡薄膜进了气敏性质研究,结果表明,在温和的测试条件下,如室温、常压、干燥的空气背景等,该氧化锡薄膜对二氧化氮气体具有良好的探测能力,检测限为1.0μL·L^-1。     

Cabletel－503技术和综合网络工程

Ｃａｂｌｅｔｅｌ－５０３技术和综合网络工程窦维德（上海东电电子技术发展有限公司）Ｃａｂｌｅｔｅｌ－５０３技术是一个建立在ＣＡＴＶ基础上的同轴线通讯系统，其主要特点是：──在双向传输的ＣＡＴＶ网络上实现电视电话二网合一，同时运行，互不干扰。──系统由计...     

基于InAs单量子点的单光子干涉

利用分子束外延生长 InAs 单量子点样品,测量了温度为 5 K 时单量子点的荧光(PL)光谱.采用时间关联光子强度测量(HBT)验证了 PL 光谱具有单光子发射特性.单光子通过马赫曾德尔 (MZ) 干涉仪,验证了单光子自身具有干涉特性.测量了当 MZ 干涉仪两臂偏振方向的夹角改变时对应的单光子干涉及条纹可见度的变化. 关键词： 量子点单光子源 反群聚效应 马赫曾德尔干涉     

电气工程技术实践教学项目集成化建设浅议

实践教学项目建设是工程技术专业实践教学体系建设中的重要环节,以技术集成为核心规划建设实践教学系统,为构建内涵丰富、效能集成的工程实践教学体系奠定了比较扎实的基础。     

发射天线对毫米波全息成像雷达成像质量影响

基于菲涅耳(Fresnel)衍射理论和傅里叶(Fourier)光学理论建立了毫米波全息成像雷达理论模型,其中重点考虑发射天线波束宽度对成像质量的影响。采用矩阵实验室软件平台(Matlab)编制了仿真程序,分别考虑超窄波束、一般波束和超宽波束三种条件下的系统成像效果。仿真结果表明:适当地优化发射天线性能,有助于获得质量更佳的全息成像。     

Pressure- and temperature-dependent luminescence from Tm3+ ions doped in GdYTaO4

Luminescent properties of Tm³⁺-doped GdYTaO₄ are studied for exploring their potential applications in temperature and pressure sensing.Two main emission peaks from ³H₄→³H₆ transition of Tm³⁺are investigated.Intensity ratio between the two peaks evolves exponentially with temperature and has a highest sensitivity of 0.014 K^?1 at 32 K.The energy difference between the two peaks increases linearly with pressure increasing at a rate of 0.38 meV/GPa.Intensity ratio between the two peaks and their emission lifetimes are also analyzed for discussing the pressure-induced variation of the sample structure.Moreover,Raman spectra recorded under high pressures indicate an isostructural phase transition of GdYTaO₄ occurring at 4.46 GPa.     

Gate tunable Rashba spin-orbit coupling at CaZrO3/SrTiO3 heterointerface

High mobility quasi two-dimensional electron gas (2DEG) found at the CaZrO₃/SrTiO₃ nonpolar heterointerface is attractive and provides a platform for the development of functional devices and nanoelectronics. Here we report that the carrier density and mobility at low temperature can be tuned by gate voltage at the CaZrO₃/SrTiO₃ interface. Furthermore, the magnitude of Rashba spin-orbit interaction can be modulated and increases with the gate voltage. Remarkably, the diffusion constant and the spin-orbit relaxation time can be strongly tuned by gate voltage. The diffusion constant increases by a factor of ～ 19.98 and the relaxation time is reduced by a factor of over three orders of magnitude while the gate voltage is swept from -50 V to 100 V. These findings not only lay a foundation for further understanding the underlying mechanism of Rashba spin-orbit coupling, but also have great significance in developing various oxide functional devices.