A MINI MULTI-GAS DETECTION SYSTEM BASED ON INFRARED PRINCIPLE

To counter the problems of gas accidents in coal mines, family safety resulted from using gas, a new infrared detection system with integration and miniaturization has been developed. The infrared detection optics principle used in developing this system is mainly analyzed. The idea that multi gas detection is introduced and guided through analyzing single gas detection is got across. Through researching the design of cell structure, the cell with integration and miniaturization has been devised. The way of data transmission on Controller Area Network (CAN) bus is explained. By taking Single-Chip Microcomputer (SCM) as intelligence handling, the functional block diagram of gas detection system is designed with its hardware and software system analyzed and devised. This system designed has reached the technology requirement of lower power consumption, mini-volume, big measure range, and able to realize multi-gas detection.     

Investigation of a liquid-liquid extraction system based on non-ionic surfactant-salt-H2O and mechanism of drug extraction

Based on the investigation of a non-ionic surfactant-salt-H₂O liquid-liquid extraction system, general rules concerning salt selection are concluded and the mechanism of phase separation is explained. The extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydrochloride (PCN) in such a system is studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, which means that quantitative extraction is realized, while that of PCN is 77%. This system produces distribution coefficients (K_D) of 12.3 and 2.6, respectively, for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet absorbance; and molecular fluorescence spectra change of the drugs in the system studied.     

Liquid-liquid Extraction System Based on Non-ionic Surfactant-salt-H_2O and Mechanism of Drug Extraction

The utilization of solid-liquid extraction system based on polymer-(NH4)2SO4 -H2O on separation of metal ions and bio-active substances has been summarized1. Cloud point extraction (CPE) benefits the environment and has been used in separation of metal chelates, biomacromolecules and in pretreatment of environmental samples2-4. In a 10 mL color comparison tube 20% PEG-1000 and 2.5 g (NH4)2SO4 were chosen as phase separation condition at pH 5.5. The average extraction efficiencies we…     

Glass capillary columns for separation of free organic acids

Glass capillary columns have been prepared without acidic additive in the stationary phase, from which free organic acids elute as sharp and symmetrical peaks. The required surface in the borosilicate glass capillary was generated by a combination of leaching with aqueous HCl and deposition of colloidal silica particles; it can be coated with stationary phases have a broad range of polarity. Aqueous samples containing free organic acids can also be analyzed in such columns in an isothermal mode.     

A new Far-Infrared Fourier Spectrometer

Summary This article describes a new commercial Far-Infrared Fourier Spectrometer system which has been developed for routine spectroscopy in the 10–1000 cm^–1 spectral region. The instrument incorporates real-time data processing and has been automated wherever possible for foolproof operation. A versatile sample chamber allows a wide range of spectroscopic studies to be performed, on solids, liquids and gases over a wide range of temperatures. A number of spectra are presented to illustrate the performance and typical applications of this Fourier spectrometer.

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Ein neues fourier-spektrometer für das ferne infrarot

Zusammenfassung Nach einer kurzen Einführung in die Methode der Fourier-Spektroskopie wird ein neues kommerzielles Fern-Infrarot-Fourier-Spektrometer mit real-time Datenverarbeitungsanlage beschrieben. Das Gerät ist für die Spektroskopie im Bereich 10–1000 cm^–1 konstruiert und weitgehend automatisiert. Eine vielseitig verwendbare Probenkammer ermöglicht umfangreiche spektroskopische Untersuchungen von Festkörpern, Flüssigkeiten und Gasen in einem sehr großen Temperaturbereich. Anhand einer Reihe von Spektren werden Leistung und typische Anwendungen dieses Fourier-Spektrometers erläutert.

Lecture presented at Euroanalysis I Conference, 28. 8.–1. 9. 1972 in Heidelberg, Germany.     

基于CAN总线的运动控制通讯系统设计

数字量驱动的运动控制要求通讯系统具有良好的实时性和可靠性。设计了一种基于CAN总线的多节点多通道的运动控制通讯系统,以FPGA为节点控制器,通过SJA1000收发运动控制数据,并行发送到各通道驱动器的数模转换器中。FPGA模块由Verilog HDL编写,通过参数传递和生成块的方法简化代码,提高系统的可移植性,移植时只需改变两个常量值即可适应各个节点不同的通道数和位宽。实验表明,通讯系统每帧耗时约120us,最高帧频可达8.5kHz,误码率低于10^-8,实时性和可靠性较好。     

Direct quantification of mono- and di-D-α-tocopherol polyethylene glycol 1000 succinate by high performance liquid chromatography

A simple and direct reversed-phase high performance liquid chromatography (RP-HPLC) method with UV detection was developed and validated for the determination of mono- and di-D-α-tocopherol polyethylene glycol 1000 succinate (TPGS 1000) in TPGS mixture. Before the HPLC analysis, mono- and di-TPGS 1000 were separated by simulated moving bed (SMB) chromatography system and characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). The mass spectrometric results confirmed that the molar mass distribution of TPGS prepared in our laboratory was very close to that of the product of Eastman Chemical Company with similar nˉ (average polymerization degree), M(n)ˉ (number-average molecular weight) and M(w)ˉ (weight-average molecular weight). The HPLC analysis was carried out on a C30 analytical column with mobile phases comprised of acetonitrile (A) and isopropanol (B) in gradient conditions. Validation of the analytical method was done on the following parameters: system suitability, linearity, limits of detection and quantification, accuracy and precision, method robustness and solution stability. The linearity of the calibration curves for mono- and di-TPGS 1000 from both sources was found to be good (r(2)>0.9996). The recovery values were from 94.6% to 103.3% for mono-TPGS, and 93.5% to 103.3% for di-TPGS. This method could be successfully used in the direct quantification of mono- and di-TPGS in TPGS 1000 mixture using TPGS standards with similar molecular mass distributions although derived from different sources.     

基于装备的IETM技术资料拆分模型研究

为了解决技术资料难于拆分、归类、全面展示及手册研制后期数据难于共享等问题,通过将S1000D标准与本单位装备IETM手册编制过程相结合,采用标准分析方法、规范分类原则,从分析装备技术资料来源开始,设计数据模块所对应的信息集,建立面向装备系统结构的技术资料拆分模型,使技术资料的拆分变得简单易行且更符合标准要求,保证了IETM研制的一致性,为装备全寿期提高技术信息的重用性、可维护性、共享性和实时有效性奠定基础,极大地提升了IETM手册编制效率。     

基于S1000D标准的技术出版物公用信息管理研究

为解决飞机技术出版物中公用信息的管理问题,提高信息的重用性和数据交换的便利性。通过对S1000D标准中公用信息库(CIR)概念的介绍,结合CIR在某大型客机维修类技术出版物编写中的实际应用情况,具体说明了CIR在公用数据管理、技术出版物编写、数据交换方面的优势,及其在提高技术出版物质量方面所起的重要作用。     

Passive Q-switch and mode-locking modulators for Nd:hosted lasers

Four kinds of currently available Nd:hosted laser passive Q-switch and mode-locking modulators: plastic dye sheet, LiF:F₂⁻ color center crystal, Cr⁺⁴ :YAG crystal and RG1000 colored glass filter were investigated in detail and summarized for comparison for the first time. The LiF:F₂⁻ crystal with outstanding annealability, long lifetime, low cost and operability at high repetition rates is highly recommended.