基于PCI总线的工业CT高速数据采集软件设计

在工业CT数据采集中，由于有大量的数据要进行传输，因此选择快速总线来提高数据的传输速率是非常重要的。PCI局部总线是一种高通过率的I／O总线，它具有高性能、数据完整性和软件兼容性好等特点，使用PCI总线可以有效地进行高速数据传输。在Windows95／98平台下，基于PCI总线控制器S5933，利用VtoolsD开发工具及Visual C＋＋语言和汇编语言，实现了DMA功能的数据传输驱动软件，实验证明软件性能满足设计要求，因此该软件设计是成功的。     

反应堆模拟保护系统组件测试装置的开发

本文探讨了如何利用数字化自动控制技术对模拟反应堆保护系统组件进行测试。在对原测试方法研究分析的基础上,提出了引入数字化自动控制技术进行模拟组件测试的方案。采用DCS技术,辅以总线通讯、软件等技术,开发专门的测试装置。使用新测试装置代替人工手动方法进行组件测试,将大大提高测试效率、提升测试结果的准确性,降低了测试工作负荷,进而保证测试进度和组件质量满足项目要求。     

悬浮式测井中子发生器

井下中子发生器高压倍加电路采用中子管悬浮式供电，使高电场强度的空间范围缩小，高电场强度区间内单位距离的电压降减少了1／3左右。在悬浮式系统中采用脉宽调制式气压自动控制，保证了中子发生器能在高温条件下稳定工作。     

基于Linux平台的辐射信息可视化远程分析软件设计

在Linux平台上，基于TCP／IP网络技术设计出了一个通用可靠的辐射信息可视化远程分析软件，它可以实现在远端对快速辐射信息采集系统进行可视化调试和实时监控，确保了操作安全、直观和及时，详细阐述了该软件的设计思想，对设计通用的辐射信息采集系统的调试和监控软件具有借鉴意义。     

基于VME总线的嵌入式Linux应用的研究

介绍了在高能物理实验的数据获取读出系统中应用嵌入式Linux的可行性分析与关键技术。首先介绍测试系统的硬件平台与软件框架。重点介绍在读出系统中实现嵌入式Linux应用的关键技术—寄存器读写、CBLT传输、中断处理、多线程技术、cache相关的处理等。系统开发基于VME总线,通过修改Linux内核与vme_universe驱动,解决了开发过程中的相关问题。最后给出系统测试运行结果,基于Linux的读出系统已经可以配合在线软件较为稳定地运行,系统性能达到预期效果,验证了在高能物理实验中采用基于Linux的读出系统的可行性。     

基于VME总线的高速A／D缓冲系统的研制

本文介绍一种基于ＶＭＥ总线的高速Ａ／Ｄ缓冲系统的原理和结构。着重阐述了高速数据采集技术，高速ＦＩＦＯ缓冲技术，存储器总线切换技术，ＶＭＥ及ＰＣ／ＩＳＡ总线接口技术在本系统中的成功应用。     

C／S数据处理系统及其在DECnet上的实践

本文介绍了ＶＡＸ－ＰＣ构成的异构ＤＥＣｎｅｔ网络中实施Ｃ／Ｓ数据处理系统的一般方法，并以一个Ｃ／Ｓ方式聚变实验数据处理系统为例，详细说明了ＶＡＸ－ＰＣ在ＤＥＣｎｅｔ环境下的Ｃ／Ｓ系统的实现方法。通过对ＶＡＸ集中式处理系统与Ｃ／Ｓ方式处理系统的性能评价说明了Ｃ／Ｓ方式的优越性。     

脉冲中子发生器高压控制系统的自动控制设计

针对在研制脉冲中子全谱测井仪过程中传统高控系统难以对不同测井模式产生多种阳极控制时序,难以达到阳极高压、灯丝供电、靶压三者的有序的控制使中子产额稳定的要求。设计本脉冲中子发生器自动控制系统能够实现阳极高压双爆发时序,能在非弹模式下兼测得Σ及活化谱;本系统还能实现中子发生器多种状态的实时测量,靶压的PWM控制,灯丝电流的自动控制使中子产额稳定达到脉冲中子全谱稳定测量的目的。     

基于Saber仿真的X球管电源设计与实现

高压直流电源与灯丝加热电源是影响X射线球管射线剂量、成像质量等因素的两个至关重要部分。基于Saber软件的仿真,设计制作了一台适应多种X射线球管供电的电源系统。系统输入电压为32 V,其中高压直流电源结合高频技术,采用负高压输出,具有放射小、不易击穿、易于X球管散热等优点,能够有效延长X射线球管的工作寿命。整个系统采用STM32作为控制,实现对高压直流源电压、管电流、高压工作脉宽的控制。最后将高压直流电源、灯丝加热电源与X射线球管整机安装在装有高压油的密封盒中。实验测试表明,该电源系统安全、稳定、高效率,达到了设计要求。     

小型单极静电加速器自动控制系统研制

本文研制了针对大气污染物PM2.5分析的小型单极静电加速器的自动控制系统。基于TCP/IP协议建立了分布式控制系统,数据传输采用了多种协议和总线技术,采用面向虚拟仪器的图形化编程方法进行了软件开发。系统在软件和硬件两方面采取了一系列抗干扰措施,极大地减少了高压打火等因素对测控系统的干扰。该控制系统工作稳定、抗干扰能力强,满足了加速器长时间运行的要求。     

多通道高速数据采集与处理装置的研制

介绍了一种多通道数字信号处理装置的基本技术指标、基本结构和系统工作原理。它包括前端放大、A／D转换、数据缓存FIFO、数字信号处理等电路设计以及系统的设计。本系统具有较通用性,可以应用于各种需要高速数据采集与高速数据处理的仪器之中。     

Atomic mixing at metal–oxide interfaces by high energy heavy ions

We study the atomic mixing at metal (Bi or Au)/oxide (SiO₂ or Al₂O₃) interfaces under 150–200 MeV heavy ion irradiation. Irradiation-induced interface mixing state is examined by means of Rutherford backscattering spectrometry (RBS). For Bi/Al₂O₃ interfaces, the heavy ion irradiations induce a strong atomic mixing and the amount of the mixing increases with increasing the electronic stopping power for heavy ions. By comparing the results with that for 3 MeV Si ion irradiation, we conclude that the strong atomic mixing observed at Bi/Al₂O₃ interfaces is attributed to the high-density electronic excitation. On the other hand, for other interfaces (Bi/SiO₂, Au/Al₂O₃ and Au/SiO₂), atomic mixing is rarely observed after the irradiation. The dependence of atomic mixing on combinations of irradiating ions and interface-forming materials is discussed.     

北京同步辐射高重频超快X射线衍射实验方法发展

基于北京同步辐射装置(Beijing Synchrotron Radiation Facility,BSRF)发展了具有皮秒分辨率的高重复频率超快X射线衍射(Ultrafast X-ray Diffraction,UXRD)技术。在重复频率310 kHz下开展了SrRuO_3(SRO)/SrTiO_3(STO)薄膜样品的超快X射线衍射实验,获得了高质量实验数据,与重复频率为1 k Hz的实验相比,信噪比(Signal to Noise Ratio,SNR)有了明显的提高。但是,高重复频率泵浦激光也导致了静态加热问题更加明显,对此进行了分析,给出了实验设计指导意见。     

高精度稳流电源控制系统中ADC、DAC芯片的应用

介绍了由高性能14位D／A转换芯片MX7534、24位A／D转换芯片AD7714与89C51单片机连接而组成的高精度稳流电源控制系统的原理，给出了接口电路和编程方法。     

Surface molecular degradation of high performance carbon/bismaleimide composites induced by proton irradiation

This work aims to identify and describe the effects of proton irradiation in ultra high vacuum environment on the surface degradation of high performance carbon/bismaleimide composites used in aerospace. The changes in surface molecular structure and surface chemical composition with increasing irradiation fluence were studied by Attenuated total reflection Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, respectively. The evolution of surface morphology and surface roughness were characterized by atomic force microscopy. The results indicated that the proton irradiation caused surface degradation of the carbon/bismaleimide composites by altering their surface chemical structure and surface morphology. The surface chemical bonds were broken largely and the extent of carbonification at the surface layer of the composites was enhanced with increasing irradiation fluence. The increment in the carbon concentration and the sharp reduction in the oxygen and nitrogen concentration with increasing irradiation fluence were caused by the emission of some oxygen-containing and nitrogen-containing small molecules from the material surface under high vacuum environment. The surface roughness firstly increased under the fluence lower than 5 × 10¹⁵ cm⁻², and then decreased after the irradiation fluence increased to some extent.     

多通道同步高速数据采集系统研制

介绍了一个最高采样率为100MHz，采样精度为8bit，基于PCI总线和计算机并口的8通道同步高速数据采集系统的设计，整套系统具有同步误差小、触发方式多样、操作灵活等特点。     

Investigation on the strain of SiGe/Si heteroepitaxial system during high temperature annealing by BiBS/Channeling

1 INTRODUCTIONSilicon-germanium (Sil--.Ge.) is playing an increasingly imPortant role in modernvery-large scale integration (VLSI) technology, paxticulaxly in high-speed devices for fu-tu-re telecommwhcation applications.[1] when si1--.Ge. alloy filins are grown epittalanYon Sillcon substrates, there exists a lattice nilsmatch at the interface. This Ansmatchcauses a strain in the Si1--.Ge. aJloy filIn, which is comPressive in the plane of the in-terface and tensile perpendicular to i…     

Porous media approach in thermohydraulic analysis of high temperature reactors in pressurized/depressurized cooldown: An improvement

The current study aims at introducing a 2D and fast-running code for the issues pertinent to design, analysis and safety in modular high temperature reactors. While the porous media approach is only applied to pebble bed type, the analysis in this paper covers both pebble bed and prismatic reactor.A time-dependent mass equation along with energy conservation equation for the cooling gas and a time-dependent energy conservation equation for the solid was solved. Appropriate series of constitutive equations (e.g. heat transfer coefficient, effective heat conductivity of solid, heat transfer coefficient, pressure drop etc.) has been recruited as well. In addition a finite-volume method is employed for spatial discretization. The SIMPLET algorithm has been used to solve the velocity and pressure linked to the momentum equation. The method of SIMPLET for natural convection is lot more advantageous over the SIMPLE method and will improve the results. Our developed code utilizes advantages of both Zehner and Schlünder and Kasperek and Vortmeyer models which lead to better results. In addition, in Thermo Hydraulic Porous Program (THPP), the Rhie-Chow technique is also used to correct the velocity components while dealing with the discretization problem of the pressure gradient. In the codes developed so far, staggered grids is usually used in computations. However, here we have adopted most of the advantages of Rhie-Chow technique in precision and computational cost.Making use of some simplified assumptions made by the benchmark definition, the core has been modeled in form of 2D-geometry. The calculations below deal with the loss of cooling accidents with or without depressurization. Having compared 2D results of THPP, the well-established thermal-hydraulics codes of THERMIX (Banaschek, 1983) and TH3D (Hossain, 2008) to simulate pebble bed and block fuel elements, it becomes clear that regarding the transient behavior during a depressurized loss of coolant accident, there exists a good agreement. Besides, there were detected more considerable differences between the results of the two codes regarding the pressurized loss of cooling accident. The program code shall be generally applicable for modular High Temperature Reactors (HTRs) e.g. pebble fuel and block fuel elements.