食品分析与分析仪器

食品分析包括许多不同的领域，受到越来越广泛的重视，现代分析仪器与计算机的结合为食品分析提供了强有力的手段，本文综述了分析仪器在食品分析某些方面应用的新进展。     

X射线过程分析仪器及其应用

介绍了基于现代Ｘ射线荧光光谱分析法的过程分析仪器，及其在冶金、地质、半导体材料等部门中的应用。     

略论分析仪器与仪器分析的关系

根据笔者40年来从事分析仪器开发研究和分析仪器应用研究的经验、教训,从理论上和实践上论述了分析仪器离不开仪器分析,仪器分析离不开分析仪器的观点;提出了分析仪器工作者与仪器分析工作者应相互沟通的理由;同时,对分析仪器工作者与仪器分析工作者应如何沟通的问题进行了初步探讨.这些观点、理由和探讨,对促进我国的分析仪器水平的提高、促进我国的分析测试技术水平的提高和我国的分析测试技术、分析仪器尽快赶超国际先进水平将具有重要现实意义.     

现代分析仪器发展的前沿技术和设计思想

评述了近年来现代分析仪器发展的前沿技术和设计思想。讨论了为赶上现代分析仪器的发展趋势，我国应采取的措施。     

大学现代仪器分析课程理论和实验教学的改革思路

现代仪器分析作为一门实践性较强的专业基础课,对学生实践能力的培养起到了积极的推动作用。本文简述了现代分析仪器课程在理论教学和实验教学中的应用,包括仪器分析实验教学中的应用、实验设计中的应用、专业实验中的应用、毕业论文中的应用、创新研究中的应用、药物分析及化学计量学中的应用。分析了理论教学和实验教学改革取得的效果和存在的问题。     

国外分析仪器发展特点和趋势预测

分析仪器是发展现代科学技术和进行工农业生产必不可少的有力工具,它的应用范围包括物质的成分分析、结构分析、微区分析和状态分析。工农业生产和科学研究进行材料和化学特性的鉴别和测定都离不开它,故分析仪器一     

荧光分析仪器及市场分析

对荧光分析仪器的发展历史作了简介。对荧光分析仪器的应用、开发情况和市场特点作了分析。简单讨论了目前国内外荧光分析仪器及技术的现状和发展趋势。     

现代分析仪器发展的前沿技术和新思想

本文评述了近年来已经显现、并将在２１世纪初期深入发展的现代分析仪器科技若干前沿技术手新思想,讨论了这些前沿技术和新思想的内涵、意义及对我国分析仪器科技现代化发展的影响,提出了若干看法。     

略论分析仪器与仪器分析的关系

本文根据笔者40年来从事分析仪器开发研究和分析仪器应用研究的经验、教训，从理论上和实践上论述了分析仪器离不开仪器分析、仪器分析离不开分析仪器的观点；提出了分析仪器工作者与仪器分析工作者应相互沟通的理由；同时，对分析仪器工作者与仪器分析工作者应如何沟通的问题进行了初步探讨。这些观点、理由和探讨，对促进我国的分析仪器水平的提高、促进我国的分析测试技术水平的提高和我国的分析测试技术、分析仪器尽快赶超国际先进水平将具有重要现实意义。     

现代分析技术在薄膜材料研究中的应用

介绍了几种现代分析仪器和技术的特点及其在薄膜材料研究中的应用情况。指出要充分了解各种分析技术的特点并加以综合运用 ,才能实现对薄膜材料更深入、更全面的认识     

一种强有力的表征手段——穆斯堡尔谱学

介绍穆斯堡尔谱仪作为现代高科技表征手段的意义,论述穆斯堡尔效应的基本原理,讨论穆斯堡尔谱学及其特点,介绍测量原理,并与其它精细测试仪器设备作比较。     

Investigation of a thermal-stress state of a heated radiochemical apparatus

Features of the formation of a nonuniform temperature field and the appearance of thermal stresses in linked elements of structures that are washed with media at substantially different temperatures were studied on a radiochemical apparatus. The level and dynamics of changes in temperature stresses in the body of the studied apparatus were found from solution of a static boundary-value problem of thermal elasticity in an axially symmetric formulation by the finite-element method. To specify one of the boundary conditions necessary for solving this problem, the temperature field on the apparatus’s exterior surface was determined experimentally with a NEC Thermo Tracer TH-9100 thermal imager. Other boundary conditions were determined from the results of physical modeling and from approximate analytical solutions. It has been established that the maximum thermal stresses arise during the initial short period when the apparatus is heated by overheated steam supplied into it.     

Role of the golgi apparatus in cellular pathology

The Golgi apparatus response to pathological disorders is predominantly as an intermediary component of membrane biogenesis where it is involved in processing, sorting and secretion of materials via secretory granules, and in the formation of lysosomes. A common initial response of the Golgi apparatus to any stress is an alteration or cessation of secretory activity. In the transformed cell, the Golgi apparatus is altered both morphologically and biochemically, suggesting a shift from a secretory to a membrane-generating mode of functioning. However, since fewer or less well-developed Golgi apparatus are frequently found in transformed cells, analytical methods of membrane isolation developed for normal tissues may not always yield equivalent results when applied to tumors. Cell surface alterations characteristic of malignant cells may result from modifications occurring at the level of the Golgi apparatus. Some lysosomal dysfunctions may result from underglycosylation of acid hydrolases by the Golgi apparatus. The use of cell-free systems between endoplasmic reticulum and Golgi apparatus or within Golgi apparatus cisterane is providing a new approach to the elucidation of the role of the Golgi apparatus in normal as well as pathological states.     

Thermal response simulation for tuning PID controllers in a 1016 mm guarded hot plate apparatus

A mathematical model has been developed and used to simulate the controlled thermal performance of a large guarded hot-plate apparatus. This highly specialized apparatus comprises three interdependent components whose temperatures are closely controlled in order to measure the thermal conductivity of insulation materials. The simulation model was used to investigate control strategies and derive controller gain parameters that are directly transferable to the actual instrument. The simulations take orders-of-magnitude less time to carry out when compared to traditional tuning methods based on operating the actual apparatus.The control system consists primarily of a PC-based PID control algorithm that regulates the output voltage of programmable power amplifiers. Feedback parameters in the form of controller gains are required for the three heating circuits. An objective is to determine an improved set of gains that meet temperature control criteria for testing insulation materials of interest.The analytical model is based on aggregated thermal capacity representations of the primary components and includes the same control algorithm as used in the actual hot-plate apparatus. The model, accounting for both thermal characteristics and temperature control, was validated by comparisons with test data.The tuning methodology used with the simulation model is described and results are presented. The resulting control algorithm and gain parameters have been used in the actual apparatus without modification during several years of testing materials over wide ranges of thermal conductivity, thickness, and insulation resistance values.     

空分气体中痕量CO和CO2的GC-HFID分析

当空分装置内富集了大量的一氧化碳和二氧化碳时，容易导致空分主冷凝蒸发器发生爆炸并引起泄漏，因此准确测定空分气体中痕量一氧化碳和二氧化碳有着重要的意义。本文介绍采用气相色谱法一氢火焰离子化检测器分析空气和氮气中痕量一氧化碳和二氧化碳，并对分析条件进行了优化。     

A Spectrophotometric Apparatus with Laser Sources for Measurements of Fast Transient Signals

Abstract

A double beam spectrophotometric apparatus, based on laser light sources and on photodiode detectors, was built in order to perform accurate measurements of small concentration changes as those produced in chemical relaxation experiments. Relaxation techniques, where small and fastly decaying signals have to be monitored, call for high analytical sensitivity. To improve this figure of merit, the choice of a laser source proved to be particularly advantageous, since the very high light intensity, providing a remarkable reduction of the shot noise, allows signals of good quality to be obtained without amplification problems.

The measured noise was found to be close to the calculated noise, which represents the theoretical lower limiting value. Under the best conditions the signal-to-noise ratio was improved by a factor 40 with respect to a commercial apparatus equipped with conventional light source, monochromator and photomultipliers. It is shown that the circumstances where the use of the present apparatus is specially suitable are those where the dynamic techniques become superior to the static methods in the determination of thermodynamic parameters of reacting systems.     

野外X荧光分析仪的开关电源设计

野外X荧光分析仪是一种新型的核心地质仪器,它能在野外现场快速测定Cu,As等多种重要元素。本文介绍了野外X荧光仪特殊开关溻源设计中的几个要素,重点分析了PWM电源转换电路的原理,TL494控制器,以及关键参数和器件的选择等问题。     

电磁感应式磁化率定性分析装置原理与结构

介绍一种磁化率定性分析装置,该装置可直接定性分析单组分大分子和同分异构体样品。利用不同分子的磁化率、磁导率、磁滞等磁谱特性不同的特点,将被测样品置于磁场中,通过测量和记录样品所产生附加磁场的互感电动势变化,可以对被测样品作定性分析。分析过程对样品没有破坏性,具有操作简单、直观、不受质量范围限制的优点。     

High-pressure phase equilibria with compressed gases

An apparatus is described that is capable of determining high-pressure vapor-liquid equilibrium, liquid-liquid equilibrium, solid-liquid-vapor equilibrium, vapor-liquid-liquid equilibrium, and mixture critical points and transitions. The device is capable of temperatures to 150 degrees C and pressures to 300 bars (higher with slight modifications). The construction and operation are described in detail and do not require the use of mercury. This method requires very low sample volumes and no analytical equipment nor system-specific calibration. The apparatus was verified by comparison with literature data for the decane-CO(2) mixture and CO(2)-ionic liquid [1-hexyl-3-methyl-imidazolium bis(trifyl)imide)] systems. The experimental data have excellent agreement with the literature data that used different experimental methods. A rigorous error analysis of the system is also presented.