分布式计算机实时数据传输板的设计与实现

从军用光电系统实时数据传输的需求出发,提出了基于VxWorks实时操作系统PCI总线双机数据传输板的设计方案.经测试,数据传输速率达到94 MB/s,能够满足军用光电系统实时数据传输要求.     

基于PCI总线的单圈绝对式光电轴角编码器实时数据采集系统

介绍了一种针对单圈绝对式光电轴角编码器而设计的基于PCI总线的实时数据采集系统.该系统以PLX公司开发且服从PCI2.1协议的PCI9052为接口芯片,利用功能强大的CPLD作为控制单元.采用TI公司生产的高性能A/D器件ADS803E作为核心器件对线阵CCD输出的信号进行实时采集,并给出了板卡调试方法和如何用合适的驱动程序开发工具编写驱动程序.实验证明,该采集卡满足单圈绝对式光电轴角编码器数据采集的需要.     

两种离子化技术气相色谱-串联质谱法测定青菜与草莓中3种有机锡类农药残留

采用电子轰击(EI)和正化学(PCI)两种电离源技术,建立了气相色谱-串联质谱(GC-MS/MS)同时测定青菜和草莓中三环锡、三苯锡、苯丁锡农药残留的分析方法。样品经氢溴酸消解,丙酮-正己烷提取,经衍生后由Florisil固相萃取柱净化,分别采用EI和PCI两种电离源进行选择反应监测模式测定,采用基质匹配外标法定量。结果显示,在0.05~1.0 mg/L质量浓度范围内,3种有机锡农药呈良好线性,相关系数均大于0.998。两种方法中目标物的定量下限分别为0.019~0.042 mg/kg和0.009~0.042 mg/kg,均能满足国内外的限量要求。在0.05、0.10、0.20 mg/kg加标水平下,目标物的平均回收率为70.1%~93.9%,相对标准偏差(RSD)均小于10%。两种方法线性均较好,灵敏度较高,可用于水果蔬菜中有机锡农药的测定,且两种方法可实现互补,有助于提高定性和定量的可靠性。     

DVB传输流捕获系统的实现

研究了DVB传输流实时捕获系统的结构及其实现方法．该系统的硬件利用复杂可编程逻辑器件和总线接口芯片,实现了传输流与PcI总线之间的接口,软件利用设备驱动程序将硬件采集的数据流传入计算机．同时保证了高速的数据交换速率,可以对捕获的数据流进行实时的处理,该系统在DvB的分析、测试、存储、编辑和复用中都有着广阔的应用前景．     

Synchrotron X‐ray phase contrast imaging of leaf venation in soybean (Glycine max) after exclusion of solar UV (280–400 nm) radiation

The hydraulic efficiency of a leaf depends on its vascular structure as this is responsible for transport activities. To investigate the effect of exclusion of UVAB and UVB radiation from the solar spectrum on the micro‐structure of leaves of soybean (Glycine max, variety JS‐335), a field experiment was conducted using synchrotron‐based phase contrast imaging (PCI). Plants were grown in specially designed UV exclusion chambers, and wrapped with filters that excluded UVB (280–315 nm) or UVAB (280–400 nm), or transmitted all the ambient solar UV (280–400 nm) radiation (filter control). Qualitative observation of high‐resolution X‐ray PCI images obtained at 10 keV has shown the differences in major and minor vein structures of the leaves. The mid‐rib width of the middle leaflet of third trifoliate leaves, for all treatments, were obtained using quantitative image analysis. The width of the mid‐rib of the middle leaflet of third trifoliate leaves of UVB excluded plants was found to be more compared to leaves of filter control plants, which are exposed to ambient UV. The mid‐rib or the main conducting vein transports water and sugars to the whole plant; therefore, mid‐rib enhancement by the exclusion of solar UV radiation possibly implies enhancement in the leaf area which in turn causes an increased rate of photosynthesis.     

基于CPCI总线DMA方式的实时高速数据交换系统

针对在重离子同步加速器运行过程中,如何解决设备控制器与上层数据处理程序之间的高速数据交换的问题,自主研发了基于Compact PCI总线板卡,板载FPGA,DSP,SDRAM等资源,并设计了DMA完整控制逻辑,传输协议解译全部由硬件完成(FPGA)。多个软硬件模块共同实现了该实时高速数据交换系统。该系统经实测,结构完整自洽,数据传输带宽符合重离子同步加速器运行要求,实现了数据传输的实时性。重点描述该系统数据通路上的诸多技术环节,包括硬件和软件的功能划分、FPGA、DSP、驱动程序、上层应用等各环节的技术细节。该实时数据交换系统系原创性设计,系统解决了控制与数据采集系统的设备控制层与上层数据处理层之间的实时数据交换问题。     

Analysis of fluorotelomer alcohols in soils: Optimization of extraction and chromatography

This article describes the development of an analytical method for the determination of fluorotelomer alcohols (FTOHs) in soil. The sensitive and selective determination of the telomer alcohols was performed by extraction with methyl tert-butyl ether (MTBE) and analysis of the extract using gas chromatography with detection and quantification by mass spectrometry operated in the positive chemical ionization mode. The protonated molecular ion, [M+H]⁺ and a fragment ion (loss of HF + H₂O) m/z 38 less than the molecular ion were monitored to identify tentatively FTOHs in MTBE extracts of contaminated soils. The FTOHs were confirmed by treatment of the extract with a silylation reagent and observing the disappearance of the FTOH response and the appearance of peaks attributable to the [M+H]⁺ ions of the trimethylsilyl derivatives. Mass-labeled FTOHs were used as recovery and matrix internal standards. Recovery experiments on soils shown to be free of endogenous FTOHs at instrument detection limits (IDL) of 16 fg/μL for 6:2 FTOH, 10 fg/μL for 8:2 FTOH and 14 fg/μL for 10:2 FTOH yielded a limit of quantitation (LOQ) of 190, 100, and 160 fg/μL for 6:2 FTOH, 8:2 FTOH, and 10:2 FTOH, respectively when 3 g samples of soil were extracted with 1 mL MTBE. The levels of the 6:2 FTOH, 8:2 FTOH, and 10:2 FTOH in five soils contaminated with FTOHs by exposure to the laboratory atmosphere during air drying were determined. In these air-dried soils, concentrations of FTOHs ranged from non-detectable to 3600 fg/μL (0.6 ng/g) of the 6:2 FTOH in the extract of a commercial topsoil. This method was used to determine even and odd numbered FTOHs from 6:2 through 14:2 in soils from fields that had received applications of sewage sludge. Concentrations of FTOHs in these sludge-applied soils ranged as high as 820 ng/g of dry soil for the 10:2 FTOH.     

航天相机主动热控测试系统设计

为了检测航天相机主动热控系统的功能、性能及可靠性,设计了主动热控仿真测试系统。依据传热学基本定律、航天器轨道理论和热控策略,给出了计算航天相机温度场的热网络数学模型,使主动热控系统能在模拟的空间热环境中连续工作,实现了对主动热控系统的闭环仿真测试。采用两个数字电位器相串联的方法模拟温度传感器的走势,得到的最大阻值为100 kΩ,精度达到10Ω,符合设计中对总电阻和电阻变化率的需求,实现了对主动热控系统的功能、性能以及可靠性的仿真测试。     

心电图结合中性粒细胞/淋巴细胞比值对急性前壁心肌梗死患者PCI术后预后的预测价值

本文分析心电图结合中性粒细胞/淋巴细胞比值(NLR)对急性前壁心肌梗死患者PCI术后预后的预测价值.选取行PCI术的急性前壁AMI患者180例,观察其心电图和NLR水平变化,并应用Cox回归分析心电图变化、NLR水平高低与预后的相关性.180例患者不良心血管事件发生率为17.78％;NLR水平＞3人数有113人;存在有...     

A New System of the Real Time Infrared Scene Simulator

This paper represents a new real-time infrared scene simulator. It has two PENTIUM 266MHz CPUs, the hardware of Z-BUFFER and the architecture based on PCI bus. The hardware architecture of the system and the schematic diagram are given and show how the great significance was achieved. Finally , the experimental results indicate that the simulator can meet the great demand of application in practice.