STM数据采集分析计算机系统

扫描隧道显微镜(STM)是1982年问世的研究物质表面结构的新型仪器,近几年来得到了很大的发展。与其它各种类型的显微镜相比,它的最大优点是具有较高的分辨率(平行和垂直于样品表面方向的分辨率分别可达1和0.1),共弱点是数据的处理和显示功能不强。发展STM的自动控制、数据采集、实时显示和数据分析的计算机系统,对于改进仪器的性能至关重要。本文介绍我们研制的一套STM数据采集、存储、实时显示和数据分析系统,并以用该系统采集的高取向石墨数据为例,介绍系统的软件功能。     

车载无人机遥感图像采集与地面显示模块设计

针对车载无人机遥感系统中实时影像数据获取的问题,设计并实现了基于嵌入式平台的图像采集模块。以ARM微处理器和嵌入式Linux操作系统为主控核心,详细介绍了系统的整体设计架构及软硬件的实现。在完成成像设备驱动移植的基础上,基于V4L2编写数据采集程序,实现视频动态显示与图像的采集存储;基于LCD触摸屏和Qt/Embedded工具设计图像数据采集控制终端,实现拍摄控制与参数设置等功能。系统软硬件联调与实验结果表明:该系统可以通过控制终端控制成像设备完成图像采集任务,并能将所采集数据实时保存至存储设备中,实现了友好的人机交互,达到了预期效果。     

Conjugation enhancement of intramolecular exciton migration in poly(p-phenylene ethynylene)s

Efficient energy migration in conjugated polymers is critical to their performance in photovoltaic, display, and sensor devices. The ability to precisely control the polymer conformation is a key issue for the experimental investigations and deeper understanding of the nature of this process. We make use of specially designed iptycene-containing poly(p-phenylene ethynylene)s that display chain-extended conformations when dissolved in nematic liquid crystalline solvents. In these solutions, the polymers show a substantial enhancement in the intrachain exciton migration rate, which is attributed to their increased conjugation length and better alignment. The organizational enhancement of the energy transfer efficiency, as determined by site-selective emission from lower energy traps at the polymer termini, is accompanied by a significant increase of the fluorescence quantum yield. The liquid crystalline phase is a necessary requirement for these phenomena to occur, and when the temperature was increased above the nematic-isotropic transition, we observed a dramatic reduction of the energy transfer efficiency and fluorescence quantum yield. The ability to improve the exciton migration efficiency through precise control of the polymer structure with liquid crystalline solutions demonstrates the importance of a polymer's conformation for energy transfer, and provides a way to improve the energy transporting performance of conjugated polymers.     

An automated facility for neutron activation analysis

A fully automated neutron activation analysis (NAA) facility has been constructed at the Whiteshell Nuclear Research Establishment. This high-capacity facility has been designed for use with a wide variety of neutron sources, including Canada's SLOWPOKE II and MAPLE research reactors. Its pneumatic transfer system is driven by a Square-D Model 500 programmable controller, linked in turn to a Nuclear Data ND6700 computer/spectrometer. Custom software for data entry and system control has been combined with Nuclear Data software for gamma-spectrum acquisition and processing to create a flexible, easy-to-use facility for NAA. Its design and performance are discussed.     

A Memristive Element Based on an Electrically Controlled Single‐Molecule Reaction

The exponential proliferation of data during the information age has required the continuous exploration of novel storage paradigms, materials, and devices with increasing data density. As a step toward the ultimate limits in data density, the development of an electrically controllable single‐molecule memristive element is reported. In this device, digital information is encoded through switching between two isomer states by applying a voltage signal to the molecular junction, and the information is read out by monitoring the electrical conductance of each isomer. The two states are cycled using an electrically controllable local‐heating mechanism for the forward reaction and catalyzed by a single charge‐transfer process for the reverse switching. This single‐molecule device can be modulated in situ, is fully reversible, and does not display stochastic switching. The I–V curves of this single‐molecule system also exhibit memristive character. These features suggest a new approach for the development of molecular switching systems and storage‐class memories.     

PCGAP: Application to analyze gamma-ray pulse-height spectra on a personal computer under Windows NT®

PCGAP is a software code, which was written to provide gamma-ray pulse height spectrum analysis on a personal computer platform. The code was specifically developed for Windows NT for either an Intel^® or DEC Alpha^® based processor. PCGAP includes programs which can be used to control data collection using a Canberra INSPECTOR^® multichannel pulse-height analyzer. With suitable spectrum conversion routines PCGAP can be used to analyze data from almost any multi-channel analyzer. Besides the normal functions associated with a robust spectrum analysis package, PCGAP can be used for radionuclide analysis for actinides via L-X and gamma-ray spectrometry. It can be used to control and analyze data from an INEEL developed pulse injection system for individual spectrum validation. The package includes programs for the manual analysis of spectra using displays which permit the spectroscopist to interactively define the spectral continuum and peak fitting limits, and display the resulting function fitting forms.     

Automated mass spectrometry imaging with a matrix-assisted laser desorption ionization time-of-flight instrument

The automated use of a matrix-assisted laser desorption ionization (MALDI) mass spectrometer (MS) is described for image analysis of samples through implementation of new software for instrument control, data acquisition, and data analysis. The software permits automated acquisition of MS MALDI spectra to form an ordered data array and contains display features to provide images at one or more mass-to-charge ratio values. The technique can be used to scan tissue samples, blotted samples, gels, or other sample surfaces where the image analysis of that sample is required. The program achieves a time of typically 1 s per image point, permitting an analysis made up of large numbers of points with high spatial resolution up to 850 dpi. The features of the software are demonstrated in this paper with samples of printed images, where visible images can be compared to those obtained by mass spectrometry. Quantitative aspects are introduced by analyzing a series of sample spots containing different amounts of several proteins.     

A microprocessor-aided modified Simons' reactor system for electrochemical fluorination processes

A modified Simons' reactor system has been developed for electrochemical fluorination processes. This reactor employs batch mixer design criteria to enhance and enable the characterization of the mass transfer in the reactor. Four monopolar packs of electrodes, each comprised of two nickel anodes sandwiched between three nickel cathodes, were used. A more uniform anodic current density distribution was achieved and the electrode packs were oriented to serve as baffles for the mixed flow field.A custom designed and fabricated, Motorola 6800 based, microprocessor system in conjunction with an IBM Personal Computer and other accessories are employed for data acquisition, monitoring and control of the process.The uniqueness of the design and operational characteristics of this microprocessor-aided modified Simons' Reactor System will be discussed.     

Time-resolved EPR spectroscopy in a Unix environment

A computer-aided time-resolved electron paramagnetic resonance (EPR) spectrometer implemented under version 2.9 BSD Unix was developed by interfacing a Varian E-9 EPR spectrometer and a Biomation 805 waveform recorder to a PDP-11/23A minicomputer having MINC A/D and D/A capabilities. Special problems with real-time data acquisition in a multiuser, multitasking Unix environment, addressing of computer main memory for the control of hardware devices, and limitation of computer main memory were resolved, and their solutions are presented. The time-resolved EPR system and the data acquisition and analysis programs, written entirely in C, are described. Furthermore, the benefits of utilizing the Unix operating system and the C language are discussed, and system performance is illustrated with time-resolved EPR spectra of the reaction center cation in photosystem 1 of green plant photosynthesis.     

Developing a mobile app for remote access to and data analysis of spectra

Vibrational spectroscopy is a non-destructive analytical method that can be used to analyse a wide range of materials. A vibrational spectrum contains information on the chemical structure of the sample being analysed, which can be recorded rapidly. With hand held mobile device technology being considered as a relatively mature market, there is an excellent opportunity to combine vibrational spectroscopy with mobile devices for in situ analysis of samples. There are still instances where analytical instruments require being linked to desktop PC's/laptops for instrument control and data manipulation. However, mobile devices are becoming increasingly more powerful thus, enabling data manipulation on devices via cloud based technology. With desktop PC's and laptops often having a larger environment footprint than the instrumental spectrometer itself, this therefore highlights the potential for mobile spectroscopy devices. This paper reports the first development of an app (SpectralAnalyser) to enable the use of mobile devices to access and manipulate spectra and describes the different approaches and implementation issues considered during the development of apps to display spectra on Android and iOS platforms.     

Computers in Quantitative TL-Chromatography

Abstract

The paper presents a discussion of the use of computers, mainly of the micro-processor variety, in devices for the photometric quantitation of TL-chromatograms. First a brief survey is given of the principal features of contemporary photometers specifically designed for chromatographic applications. The most sophisticated and expensive of these are dual wavelength instruments and at the present state of development only these have as yet been computerized. It is, however, anticipated that in the near future the use of computers will spread also to the less sophisticated single wavelength devices with a moderate price tag. The advantages are ease of operation as well as superior performance characteristics. The former is achieved using a computer to control the internal operation of the photometer and some of the possibilities open in this regard are discussed. The improvement in performance is achieved in a different way. Photometric quantitation of TL chromotograms requires a number of mathematical operations upon the signal on its path between the light source and the output display. The computer permits the use of almost any kind of signal transforms, transforms which would be completely impractical to carry out by traditional techniques. The acquired and preprocessed signal, which in a conventional device would be directly fed to the output recorder, can be subjected to “after-processing” with a substantial further gain in performance. The results obtained by computerized analysis are available in alpha-numerical form. Both hard and soft copy devices can be used. If desired a graphical display in analog form can also be obtained. The output information provided by the computer can be stored in extremely compact form on magnetic tape or disc with very fast access and retrieval.     

Echtzeit-Datenerfassungssystem mit minimaler hardware für den Einsatz in der Routine-Massenspektrometrie im organischen Laboratorium

A low-cost on-line digital computer system for data acquisition and reduction of mass spectral information from a single focusing mass spectrometer is described. The data system is designed to handle the problems most commonly encountered in routine applications in organic chemistry. By using sophisticated programming concepts a versatile user oriented system is realised on a minimal hardware configuration. Detailed information about data flow and logical structure of the programs is given.     

2D WIN-NMR: BRUKER's PC-based display and processing package for 2D NMR data matrices

Summary Off-line retrieval and processing of data is a considerable advantage of a computer used separately from the spectrometer. 2D WIN-NMR — BRUKER's PC based display and processing package for 2D NMR data matrices — has been designed to fulfill two particular criteria: a variety of different display options allow an interactive interpretation of the 2D data and the best graphical document can be created at the end of the working session. This is accomplished making extensive use of WINDOWS based data transfer capability. For analyzing data separate from the spectrometer it is also necessary to be able to process 2D NMR datasets. 2D WIN-NMR includes all of the standard processing functions an NMR spectroscopist needs and is an easy-to-handle tool for scientific work.     

Engineering upgrades to the Radionuclide Aerosol Sampler/Analyzer for the CTBT International Monitoring System

The Radionuclide Aerosol Sampler/Analyzer (RASA) is an automated collection and analysis system designed for aerosol radionuclide monitoring for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The advantages of an automated system include minimal need for human intervention and consistent analytical data. However, maintainability and down time issues threaten this utility, even for systems with over 90 % data availability. Engineering upgrades to the RASA are currently being pursued to address these issues, as well as measures relevant to technical lessons learned from the Fukushima nuclear power plant event. Current work includes a new automation control unit and other potential improvements such as alternative detector cooling and sampling options. This paper presents the current state of upgrades and improvements under investigation.     

Entwicklung eines rechner-betriebssystems für die labordatenerfassung

The development of a computer operational system for data acquisitionAn operational controller, run on an IBM System/7, has been developed and tested for analytical data acquisition. This control system is particularly satisfactory with high external interrupt rates. It is based on self-synchronization of the analog—digital converters. The synchronization cycles serve as the trigger for various functions, e.g. for data transfer to the host computer. The interrupt servicing is done intermediately in an asynchronous manner.     

Performance and scaling effects in a multilayer microfluidic extracorporeal lung oxygenation device

Microfluidic fabrication technologies are emerging as viable platforms for extracorporeal lung assist devices and oxygenators for cardiac surgical support and critical care medicine, based in part on their ability to more closely mimic the architecture of the human vasculature than existing technologies. In comparison with current hollow fiber oxygenator technologies, microfluidic systems have more physiologically-representative blood flow paths, smaller cross section blood conduits and thinner gas transfer membranes. These features can enable smaller device sizes and a reduced blood volume in the oxygenator, enhanced gas transfer efficiencies, and may also reduce the tendency for clotting in the system. Several critical issues need to be addressed in order to advance this technology from its current state and implement it in an organ-scale device for clinical use. Here we report on the design, fabrication and characterization of multilayer microfluidic oxygenators, investigating scaling effects associated with fluid mechanical resistance, oxygen transfer efficiencies, and other parameters in multilayer devices. Important parameters such as the fluidic resistance of interconnects are shown to become more predominant as devices are scaled towards many layers, while other effects such as membrane distensibility become less significant. The present study also probes the relationship between blood channel depth and membrane thickness on oxygen transfer, as well as the rate of oxygen transfer on the number of layers in the device. These results contribute to our understanding of the complexity involved in designing three-dimensional microfluidic oxygenators for clinical applications.     

Single and dual beam optical switching of resonance energy transfer

Through photonic mechanisms based on near-field coupling, laser radiation can engage with resonant energy transfer in a variety of suitably designed materials and molecular structures. Energy that has been acquired, through the initial absorption of resonant laser light, undergoes transfer between chromophores only on the throughput of off-resonant light, the process known as laser-assisted resonance energy transfer. The comprehensive results that are presented here extend and generalize the theory for both single and dual beam configurations, producing results that are applicable to media of various types including doped crystals, heterogeneous multichromophore solids, and solutions. The detailed principles, here explained in terms of both energetics and optical selection rule criteria, are specifically illustrated for a variety of materials. It is shown how general application of the theory can facilitate the elucidation of experiments, by clearly interpreting the effects of laser polarization manipulation. On further analysis of the photophysical mechanisms it is also demonstrated that such effects represent an entirely practicable basis for optical switching and logic gate operation. The additional polarization selectivity afforded by a two-beam setup proves to allow the most complete system control. With such a configuration, there is considerable promise for the realization of new optically driven logic and molecular devices.     

How gamma radiation processing systems are benefiting from the latest advances in information technology

This paper discusses how gamma irradiation plants are putting the latest advances in computer and information technology to use for better process control, cost savings, and strategic advantages.

Some irradiator operations are gaining significant benefits by integrating computer technology and robotics with real-time information processing, multi-user databases, and communication networks. The paper reports on several irradiation facilities that are making good use of client/server LANs, user-friendly graphics interfaces, supervisory control and data acquisition (SCADA) systems, distributed I/O with real-time sensor devices, trending analysis, real-time product tracking, dynamic product scheduling, and automated dosimetry reading. These plants are lowering costs by fast and reliable reconciliation of dosimetry data, easier validation to GMP requirements, optimizing production flow, and faster release of sterilized products to market.

There is a trend in the manufacturing sector towards total automation using “predictive process control”. Real-time verification of process parameters “on-the-run” allows control parameters to be adjusted appropriately, before the process strays out of limits. Applying this technology to the gamma radiation process, control will be based on monitoring the key parameters such as time, and making adjustments during the process to optimize quality and throughput. Dosimetry results will be used as a quality control measurement rather than as a final monitor for the release of the product. Results are correlated with the irradiation process data to quickly and confidently reconcile variations. Ultimately, a parametric process control system utilizing responsive control, feedback and verification will not only increase productivity and process efficiency, but can also result in operating within tighter dose control set points.     

System for the generation of standard gas mixtures of volatile and semi-volatile organic compounds for calibrations of solid-phase microextraction and other sampling devices

Standard gases are used for quality control and quality assurance, development of analysis methods and novel air sampling devices. The use of solid-phase microextraction (SPME) and other novel technologies for research in the area of air sampling and analysis requires systems/devices for reliable standard gas generation and sampling. In this paper we describe a new gas standard generating system for volatile organic compounds (VOCs) and semi-VOCs that was designed, built, and tested to facilitate fundamental and applications research with SPME. The system provided for the generation of a wide range of VOC/semi-VOC concentrations and mixing various standard gases, estimation of detection limits, testing the effects of sampling time, air temperature and relative humidity, testing the effects of air velocity and ozone on sampling/extractions. The system can be also used for calibrations of analytical instrumentation, quality control and quality assurance checks, and cross-validations of SPME with/and other sampling techniques.