基于中红外QCL的痕量CO气体传感器

为了减少CO爆炸给国民经济造成的巨大损伤,提出了一种能够快速地监测环境空气中痕量CO的气体传感器。由于CO分子基频吸收谱带的吸收线强要比泛频带和组合频带的吸收线强高出2～3个数量级,选择激射中心波长为4.65μm中红外量子级联激光器（QCL）作为光源,同时再配合长光程Herriott气室提高了CO体积分数检测下限。同时,该传感器采用单光源双探测器差分光学结构,消除了电调制光源所带来的不稳定性。实验表明：该传感器CO体积分数检测下限为2×10-6,并且操作人员可以通过替换在不同波长下运行的中红外QCL来测量其它气体。     

便携式光离子化有害气体检测仪的设计

针对室内空气污染源的多样性与传统气体检测器检测种类的单一性的矛盾,设计了一种能够同时检测多种气体的新型便携式光离子化气体检测仪.该检测仪采用了MEMS结构的离子化室和混合信号级微处理器C8051F040,减小了仪器体积,降低了仪器功耗.利用单片机控制电流跨导增益的方法,实现了仪器的双量程数据采集功能,保证了仪器在两个量...     

气体中微量水分析方法概述

概述了各种测定气体中微量水的分析方法：光腔衰荡光谱法、电解法、露点法、卡尔费休库仑法、重量法及碳化钙法的测定原理及其优缺点;并详细列举和归纳了不同种类气体产品测定水分含量所采用的方法,为企业和质监部门监控气体产品质量提供了可参考的技术信息。     

PdSe2半导体薄膜的真空硒化法制备研究

PdSe2薄膜主要通过机械剥离法和气相沉积法制得,本研究采用一种简单有效的可在SiO2/Si衬底上制备PdSe2薄膜的方法.通过高真空磁控溅射技术在SiO2/Si衬底上沉积一层Pd金属薄膜,将Pd金属薄膜与Se粉封在高真空的石英管中并在一定的温度下进行硒化,获得PdSe2薄膜.根据截面高分辨透射电镜(HRTEM)照片可...     

New nanocomposite based on poly(lactic-co-glycolic acid) copolymer and magnetite. Synthesis and characterization

The study presents the preparation of the new magnetic nanocomposite based on PLGA and magnetite. The PLGA used to obtain the magnetic nanocomposites was synthesized by the copolymerization of lactic acid with glycolic acid, in the presence of tin octanoate [Sn(Oct)₂] as catalyst, by polycondensation procedure. Magnetite was obtained by co-precipitation from aqueous salt solutions FeCl₂/FeCl₃. The particles size of magnetite was 420 nm, and the saturation magnetization 62.78 emu/g, while the PLGA/magnetite nanocomposite size was 864 nm and the saturation magnetization 39.44 emu/g. The magnetic nanocomposites were characterized by FT-IR, DLS technique, SEM, VSM and simultaneous thermal analyses (TG–FTIR–MS). The polymer matrix PLGA acts as a shell and carrier for the active component, while magnetite is the component which makes targeting possible by external magnetic field manipulation. Based on the gases resulted by thermal degradation of PLGA copolymer, using the simultaneous analysis TG–FTIR–MS, a possible degradation mechanism was proposed.     

A Thermophysical Property Databank for Technically Important Gases and Liquids

A thermophysical property databank for technically important gases and liquids has been created. It provides users with data for nearly 30 substances: monatomic and diatomic gases, air, water and steam, carbon dioxide, ammonia, some hydrocarbons, and refrigerants. The coefficients of the equations of state and equations for calculating transport properties, the ideal-gas functions, the saturated vapor pressure, and the melting pressure are provided for each substance. The system of programs allows the calculation of the compressibility factor, density, enthalpy, entropy, isochoric and isobaric specific heats, speed of sound, Joule–Thomson coefficient, viscosity, and thermal conductivity and some other properties. These values can be determined in the single-phase and two-phase regions and on the phase-equilibrium lines at temperatures from the triple point up to 500 to 1500 K and at pressures up to 100 MPa (for monatomic and diatomic gases, up to 2500 to 3000 K and 300 MPa). Properties can be calculated for the following nine combinations of independent variables: T, ; T, p; T, s; T, x; p, ; p, h; p, s; p, x; and h, s. The software of the databank has a modular structure and permits an increase in the number of substances, properties, and independent variables.     

单圆柱微波谐振法测量热力学温度的研究

利用氩气的量子力学“从头算”理论和相关实验测量结果,基于圆柱微波谐振法建立了气体折射率热力学温度计实验系统,测量了253~303 K范围内的热力学温度。通过测量圆柱微波谐振腔内4个横磁模式的微波谐振频率,获得了氩气在700 kPa附近的气体折射率,不同微波模式得到的氩气折射率一致性优于1×10^-8,进一步结合氩气的维里状态方程得到热力学温度。热力学温度T和ITS-90国际温标T90差异不确定度为11.6 mK,与国际温度咨询委员会的评估值具有良好的一致性。未来随着氩气理论计算和实验系统压力测量不确定度的深入研究,该方法测定热力学温度的不确定度会进一步改善。     

氨气敏电极法测定污染源废气中的氨

本文介绍用氨气敏电极法在WTWpH/Ion340i测试仪上测定污染源废气中氨的分析方法,以及在分析过程中应注意的问题。