航天器图像压缩小波变换的FPGA设计

中科院部博士资助基金项目( 0929361213) 资助

基于FPGA 的高分辨率图像DCT域增强

中科院“西部博士资助基金”(0929361213)

FPGA在CSR主环电源控制系统中的应用

论文介绍了基于DSP和FPGA主环电源控制系统的设计。DSP与DAC之间通过FPGA连接,并通过FPGA来控制DAC的输出。重点介绍FPGA的程序设计及其仿真结果。系统达到了设计要求,已成功应用于CSR主环控制系统。

基于FPGA的VME总线控制器及其驱动程序

本文论述了用于兰州重离子加速器冷却储存环(HIRFL-CSR)前端控制系统的总线控制器的FPGA设计及其基于ARM-Linux下的驱动程序设计。该总线控制器采用Altera公司的ACEX系列中的EP1K30实现,通过VME总线背板同其它VME设备(CPLD)通信,可读VME设备数据,监视电源运行状况,也可向VME设备发送命令和写数据,并且能够响应VME设备中断,读中断数据。为了能够通过AT91RM9200控制器访问VME总线控制器,必须为其编写相应的驱动程序。驱动程序定义了应用程序调用接口和数据格式,并实现了中断机制、多进程访问和数据的突发(burst)读写。

Effects of Naotan Pill on repair of neural cells and cognitive disorders in juvenile rats following hypoxia and ischemia

BACKGROUND: Hypoxia and ischemia induce neuronal damage, decreased neuronal numbers and synaptophysin levels, and deficits in learning and memory functions. Previous studies have shown that lycium barbarum polysaccharide, the most effective component of barbary wolfberry fruit, has protective effects on neural cells in hypoxia-ischemia. OBJECTIVE: To investigate the effects of Naotan Pill on glutamate-treated neural cells and on cognitive function in juvenile rats following hypoxia-ischemia. DESIGN, TIME AND SETTING: The randomized, controlled, in vivo study was performed at the Cell Laboratory of Lanzhou University, Lanzhou Institute of Modern Physics of Chinese Academy of Sciences, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from December 2005 to August 2006. The cellular neurobiology, in vitro experiment was conducted at the Institute of Human Anatomy, Histology, Embryology and Neuroscience, School of Basic Medical Sciences, Lanzhou University, and Department of Traditional Chinese Medicine of Gansu Provincial Rehabilitation Center Hospital, China from March 2007 to January 2008. MATERIALS: Naotan Pill, composed of barbary wolfberry fruit, danshen root, grassleaf sweetflag rhizome, and glossy privet fruit, was prepared by Gansu Provincial Rehabilitation Center, China. Rabbit anti-synaptophysin, choline acetyl transferase polyclonal antibody, streptavidin-biotin complex kit and diaminobenzidine kit (Boster, Wuhan, China), as well as glutamate (Hualian, Shanghai, China) were used in this study. METHODS: Cortical neural cells were isolated from neonatal Wistar rats. Neural cell damage models were induced using glutamate, and administered Naotan Pill prior to and following damage. A total of 54 juvenile Wistar rats were equally and randomly assigned into model, Naotan Pill, and sham operation groups. The left common carotid artery was ligated, and then rat models of hypoxic-ischemic injury were assigned to the model and Naotan Pill groups. At 2 days following model induction, rats in the Naotan Pill group were administered Naotan Pill suspension for 21 days. In the model and sham operation groups, rats received an equal volume of saline. MAIN OUTCOME MEASURES: Neural cell morphology was observed using an inverted phase contrast microscope. Survival rate of neural cells was measured by MTT assay. Synaptophysin and choline acetyl transferase expression was observed in the hippocampal CA1 region of juvenile rats using immunohistochemistry. Cognitive function was tested by the Morris water maze. RESULTS: Pathological changes were detected in glutamate-treated neural cells. Neural cell morphology remained normal after Naotan Pill intervention. Absorbance and survival rate of neural cells were significantly greater following Naotan Pill intervention, compared to glutamate-treated neural cells (P < 0.05). Synaptophysin and choline acetyl transferase expression was lowest in the hippocampal CA1 region in the model group and highest in the sham operation group. Significant differences among groups were observed (P < 0.05). Escape latency and swimming distance were significantly longer in the model group compared to the Naotan Pill group (P < 0.05). CONCLUSION: Naotan Pill exhibited protective and repair effects on glutamate-treated neural cells. Naotan Pill upregulated synaptophysin and choline acetyl transferase expression in the hippocampus and improved cognitive function in rats following hypoxia-ischemia.

Blue-violet luminescence double peak of In-doped films prepared by radio frequency sputtering

ZnO films doped with different contents of indium were prepared by radio frequency sputtering technique. The structural, optical and emission properties of the films were characterized at room temperature using XRD, XPS, UV-vis-NIR and PL techniques. Results showed that the indium was successfully incorporated into the c-axis preferred orientated ZnO films, and the In-doped ZnO films are of over 80% optical transparency in the visible range. Furthermore, a double peak of blue-violet emission with a constant energy interval (similar to 0.17 eV) was observed in the PL spectra of the samples with area ratio of indium chips to the Zn target larger than 2.0%. The blue peak comes from the electron transition from the Zn-i level to the top of the valence band and the violet peak from the In-Zn donor level to the V-Zn level, respectively.

Structural and photoluminescent properties of ZnO films deposited by radio frequency reactive sputtering

Zinc oxide films with c-axis preferred orientation were deposited on silicon (100) substrates by radio frequency (RF) reactive sputtering. The properties of the samples were characterized by X-ray diffractometer, X-ray photoelectron spectroscopy and fluorescent-spectrophotometer. The effect of sputtering power and substrate temperature on the structural and photoluminescent (PL) properties of the ZnO films was investigated. The results indicated that when the sputtering power is 100 W and the substrate temperature is 300-400 degrees C, it is suitable for the growth of high c-axis orientation and small strain ZnO films. A violet peak at about 380 nm and a blue band at about 430 nm were observed in the room temperature photoluminescence spectra, and the origin of blue emission was investigated.

Radio-resistance induced by nitric oxide to heavy ion irradiation in A172 human glioma cells

To investigate effects of nitric oxide on cellular radio-sensitivity, three human glioma cell lines, i.e. A172, A172 transfected green fluorescence protein (EGFP) gene (EA172) and A172 transfected inducible nitric oxide synthesis (iNOS) gene (iA72), were irradiated by C-12(6+) ions to 0, 1 or My. Productions of nitric oxide and glutathione (GSH) in A172, EA172 and iA172 were determined by chemical methods, cell cycle was analyzed by flow cytometry at the 24th hour after irradiation, and survival fraction of the cells was measured by colorimetric MTT assay at the 5th day after irradiation. The results showed that the concentrations of nitric oxide and GSH in iA172 were significantly higher than in A172 and EA172; the G(2)/M stage arrest induced by the C-12(6+) ion irradiation was observed in A172 and EA172 but not in iA172 at the 24th hour after exposure; and the survival fraction of iA172 was higher than that of EA172 and iA172. Data suggest that the radio-sensitivity of the A172 was reduced after the iNOS gene transfection. The increase of GSH production and the change of cellular signals such as the cell cycle control induced by nitric oxide may be involved in this radio-resistance.

基于FPGA的数字电源调节器研究与设计

详细描述了基于FPGA方案的数字电源调节器。首先介绍了数字调节器的硬件功能模块设计,重点对用于采样电源输出电流的高速高精度AD7634的工作原理做了描述,并给出了AD7634采集一个电压信号的工作波形;其次介绍了数字调节器的软件设计,包括调节器算法、功能以及在FPGA内的实现方法;最后,以一台15 A/15 V校正磁铁电源为样机,进行了闭环调节实验,给出了测试结果。

基于FPGA的CSR高频控制系统相位求解模块设计

CSR高频控制系统需要对高频正弦波激励信号的幅度、相位、频率进行稳定控制。相位arctan(Q/I)求解是必不可少的模块。论述了一种新的基于FPGA平台和对称查找表法(SBTM)的求解相位arctan(Q/I)的方法,做了详细的理论分析,给出了具体实现的代码和结果。该模块精度高,消耗资源少,可直接应用于CSR高频控制系统。