共查询到20条相似文献,搜索用时 156 毫秒
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各种外延技术已被用来在GaAs衬底上生长GaxIn1-xP外延单晶薄膜(GaInP2/GaAs).很多文献认为,在GaInP2/GaAs生长过程中会被C杂质污染.我们用高灵敏的CAMECAIMS4F型二次离子质谱仪直接测量的结果表明,污染GaInP2/GaAs的微量杂质是Si,而不是C.由GaInP2/GaAs在1.17eV附近的光致发光峰的峰值随激发强度的变化形状表明了它应属于施主-受主对复合发光.进一步分析表明,施主为处在Ga格位上的Si杂质(SiGa),受主为Ga空位(VGa). 相似文献
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尼龙1010-聚四氢呋喃多嵌段共聚物(PA-PTMG)是一种性能良好的聚合物。本文用X射线光电子能谱(ESCA)和计算机分峰技术研究了不同软硬段分子量的PA-PTMG的表面化学组成,进行了试样ESCA谱峰归属的确定。结果表明,本体嵌段效果较好,但在样品表面上O/N原子比大于体相O/N原子比,即软段富集于表面,并且分相程度高的试样较分相程度低的试样其软段在表面富集得更多。 相似文献
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利用脉冲激光法研究了在(100)SrTiO3(STO)、(100)LaAlO3(LAO)和(100)Y-ZrO2(YSZ)衬底上外延生长LaCuO4(LCO),La1.85Sr0.15CuO4(LSCO),Nd1.85Ce0.15CuO4(NCCO)和Pr2CuO4(PCO)薄膜的工艺技术。利用X光衍射仪检测了不同条件下制备的薄膜样品结构和取向。X射线衍结果表明,在事适的制膜条件下可以在这三种衬底 相似文献
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ICP/AES操作条件及氢化物发生条件对As、Se和Ge光谱信号影响的研究 总被引:1,自引:0,他引:1
本文较系统地研究了ICP/AES操作条件及酸介质。NaBH4溶液浓度对As、Se和Ge谱线强度以及信背比的影响,讨论了这些元素的最佳检测条件,考察了一些共存元素对氢化物光谱信号的影响,观察到As、Se和Ge氢化物发生中Ge的光谱信号的一些特殊行为,及Cu对Ge的氢化物光谱信号的增强。 相似文献
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尼龙1010-聚四氢呋哺多嵌段共聚物(PA-PTMG)是一种性能良好的聚合物。本文用X射线光电子能谱(ESCA)和计算机分峰技术研究了不同软硬段分子量的PA-PTMG的表面化学组成,进行了试样ESCA谱峰归属的确定。结果表明,本体嵌段效果较好,但在样品表面上O/N原子比大于体相O/N原子比,即软段富集于表面,并且分相程度高的试样较分相程度低的试样其软段在表面富集得更多。 相似文献
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本文描述一台虚拟式扫描声显微镜及应用技术研究,它的硬件特别简单,仅由一台带有超高速A/D卡和快脉冲收发卡的PC机和机械扫描系统组成,主要的功能均由软件完成,脉冲收发卡仅包括脉冲产生和高频放大器,A/D卡采用PCI总线,采样率1GSPS,数据传输率100MB/s,系统能采集并实时显示频率达百兆的未检波回波信号,采修订本以的信号经软件处理,可在屏幕上实时显示样品的A、B、C型幅度像或相位像,仪器利用信号处理技术提高信号的信噪比;进行特征提取,识别,该仪器在材料识别,电子、光电子器件和焊接质量检测等方面功能较强,具有广阔的开发应用前景。 相似文献
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A personal computer (PC)-based data acquisition and instrument control system has been developed for neutron spectrometers
in Dhruva reactor hall and Guide Tube laboratory. Efforts have been made to make the system versatile so that it can be used
for controlling various neutron spectrometers using single end-on detector in step scan mode. Commercially available PC add-on
cards have been used for input-output and timer-counter operations. An interface card and DC motor driver card have been developed
indigenously. Software for the system has been written in Visual C++ language using MS Windows operating system. This data
acquisition and instrument control system is successfully controlling four spectrometers at Dhruva reactor. 相似文献
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针对252Cf快中子、γ射线的飞行时间谱测量要求,提出并建立一种基于高速数据采集卡的新型测量系统。采用1 GHz高速A/D转换单元和现场可编程门阵列高速处理单元,进行脉冲时间序列的在线检测,时间精度为1 ns。使用相关函数法,通过PC机的数据处理、互相关函数计算和数值统计等实现中子、γ射线飞行时间谱的测量。实验结果表明,该系统可以获得252Cf自发裂变中子源的中子、γ射线飞行时间谱,与经典的飞行时间谱测量方法相比较,其图谱表达及数值结果有着很高的吻合度。 相似文献
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设计了一种新的图像注入系统来实现PC机仿真图像到红外处理系统的直接传输。首先,该系统利用USB2.0接收PC机对外场实测数据仿真得到的BMP格式文件,用FPGA控制由两个SDRAM组成的缓冲模块进行图像缓存,然后通过Camera Link接口传送出去。系统数据缓存采用乒乓操作,避免了数据处理时无法持续接收而丢失有效数据的现象。测试时用图像采集卡进行图像采集并显示。结果表明,该系统具有速度快、实时性好、稳定性高等特点,可替代光电跟瞄设备进行仿真训练及设备的动态检验。 相似文献
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本文介绍在数字声学测量分析系统中,通过双传声器信号互谱密度的计算进行声强及声功率测量的基本原理。该数学分析系统由微计算机,数字信号处理卡和A/D变换卡组成。在一个数字系统中,通过快速傅里叶变换(FET)进行互谱计算是十分有效的。本文着重介绍了,在声强的测量分析中对声强探头两传声器的固有相位差进行补偿的重要性和补偿方法,这是声强测量的重要环节。 相似文献
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基于FPGA的红外图像仿真注入系统 总被引:1,自引:0,他引:1
设计了一种新的图像注入系统来实现PC机仿真图像到红外处理系统的直接传输。首先,该系统利用USB2.0接收PC机对外场实测数据仿真得到的BMP格式文件,用FPGA控制由两个SDRAM组成的缓冲模块进行图像缓存,然后通过Camera Link接口传送出去。系统数据缓存采用乒乓操作,避免了数据处理时无法持续接收而丢失有效数据的现象。测试时用图像采集卡进行图像采集并显示。结果表明,该系统具有速度快、实时性好、稳定性高等特点,可替代光电跟瞄设备进行仿真训练及设备的动态检验。 相似文献
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A holographic technique is used to combine the information content of conventional, 2D tomographic scan images into a full-parallax, 3D reconstruction of the recorded subject. Advantages of the system over the conventional, pseudo-3D reconstructions obtained by computer image processing, or over the direct examination of the scan images by the physician, are a more realistic and detailed information to the observer, as true parallax and physical depth cues are fully maintained. 相似文献
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Schlieren技术是利用声场引起透明媒质光折射率的变化而实现声场可视化的光学成像技术。它具有对声场无干扰、快速、瞬态成像的特点。本文利用二维光学Fourier变换分析了Schlieren技术的成像原理,在采用连续激光和高速ICCD的Schlieren成像系统中,实验研究了平面波声场和线聚焦声场中换能器光学校准方法和声压的定量检测技术。发展声场瞬态和动态成像技术,观测了声波的聚焦过程和固-液界面的声场分布和变化。这些结果表明Schlieren技术是一种有效的声场可视化和定量检测的光学成像技术。 相似文献
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This paper describes a flexible, software-based scan converter capable of rendering 3D volumetric data in real time on a standard PC. The display system is used in the remotely accessible and software-configurable multichannel ultrasound sampling system (RASMUS system) developed at the Center for Fast Ultrasound Imaging. The display system is split into two modules: data transfer and display. These two modules are independent and communicate using shared memory and a predefined set of functions. It is, thus, possible to use the display program with a different data-transfer module which is tailored to another source of data (scanner, database, etc.). The data-transfer module of the RASMUS system is based on a digital signal processor from Analog Devices--ADSP 21060. The beamformer is connected to a PC via the link channels of the ADSP. A direct memory access channel transfers the data from the ADSP to a memory buffer. The display module, which is based on OpenGL, uses this memory buffer as a texture map that is passed to the graphics board. The scan conversion, image interpolation, and logarithmic compression are performed by the graphics board, thus reducing the load on the main processor to a minimum. The scan conversion is done by mapping the ultrasonic data to polygons. The format of the image is determined only by the coordinates of the polygons allowing for any kind of geometry to be displayed on the screen. Data from color flow mapping is added by alpha-blending. The 3D data are displayed either as cross-sectional planes, or as a fully rendered 3D volume displayed as a pyramid. All sides of the pyramid can be changed to reveal B-mode or C-mode scans, and the pyramid can be rotated in all directions in real time. 相似文献
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This paper describes an optical three-dimensional (3D) camera developed by combining a two-dimensional intensity image and non-contact time of flight (TOP) range image. The camera system consists of an amplitude modulated light source, an image dissector tube, a phase measuring circuit, and a host PC for system control. A semiconductor diode laser light source or a white light source and Kerr cell is used to generate continuously high frequency modulated light for bulk illumination of the scene to be viewed. A compact, 25 mm diameter image dissector camera (Hamamatsu N2730 or R4193) is used as a receiver to detect the modulated light and generate both a two-dimensional intensity image and a range image. The range is obtained by measuring the phase between the received signal and the transmitted signal. With the large detection area and the random access property of the image dissector camera, it is easy to scan systematically and electronically the illuminated area, within the frame, to identify the required object. Three different modulated frequencies (between 10 MHz and 45 MHz) have been used to obtain a range accuracy of 4 mm, over a distance of 10 m, within a time period of 10 ms per pixel. A demonstration of the three-dimensional vision system has been given, having an update time of 1 s during which a high resolution intensity image (300 × 300 pixels) is produced together with a limited number (100) of range measurements obtained for important features. 相似文献