Agilent4890D气相色谱仪的使用与故障排除

气相色谱仪具有分离效能高,分析速度快,所需样品少,可进行多组分测量等优点,用于工业生产中原料及中控产品的分析。人员素质、样品的性质、方法的选择以及仪器本身等方面的原因造成色谱分析中常常出现一些分析故障从而影响了正常分析,所以熟练掌握色谱仪的使用方法及排除仪器故障的方法非常重要。介绍了气相色谱仪的使用方法、注意事项,常见事故的分析及排除。     

气相色谱仪常见故障的检查

气相色谱仪在氯碱化工分析中占有十分重要的地位，近80％的原料中控及产品分析任务是由色谱来完成的。但是由于人、机、料等方面的原因，会出现各种各样的故障。所以掌握一种准确、快速的排除仪器故障的方法非常重要。     

氧化锆气相色谱仪在高纯氮杂质分析中的应用

文章采用氧化锆气相色谱仪,对高纯氮中的氢气、氧气、一氧化碳、甲烷及总碳等微量杂质进行了分析,这种仪器具有高灵敏度、高选择性、一次进样多组分同时分析的特点,在配备镍催化转化系统下,还可分析高纯氮中总碳含量。     

P—E703原子吸收分光光度计使用及维修的体会

P-E703原子吸收分光光度计是一种功能齐全、结构复杂的高档分析仪器,非常适用于化工、冶金、环保等行业的微量无机成份分析.使用该类精密仪器时,常由于电压、温度、湿度等波动因素影响,随时可能发生一些小的故障.这里谈两点对该仪器使用及维修的体会.一、不论是仪器操作还是仪器维修人员,了解面板上各种指示都是十分有益     

WSTT测井仪在长庆油田应用中的故障分析

WSTT交叉偶极声波测井仪是哈里伯顿公司较先进的一种成像测井仪器,在长庆油田中得到了广泛的使用,但实际使用过程中也出现了不少问题。本文通过对该仪器使用过程中出现的电流大、通讯故障、数据采集故障和下载MIT错误等常见故障进行分析,给出了故障判断的方法和流程,提出了排除故障的措施,便于维修人员参考,快速排除仪器故障。     

离子色谱法在水质分析中的应用

由于科学技术发展水平、水资源及其水质现状等多种因素存在,水质污染严重。离子色谱法作为一种分析技术,在水质分析中,该方法具有操作简单、准确度高、多组分同时测定等优点。     

基于MSP430的智能仪器自动检测装置

针对智能仪器在使用过程中由于维护人员的非专业性和使用场合的危险性造成的运行状态监测和维护中的困难,本文设计一种智能仪器自动检测装置。该装置以MSP430F5336为主控芯片,包含RS485通信,I/O口拓展,继电器驱动等电路模块,通过RS485实时读取总线上所挂载智能仪器运行参数并进行运行状态分析和故障反馈。经现场测试,该装置能实时监测状态和反馈故障。     

加强仪器分析实验教学改革,促进学生综合素质的培养

仪器分析实验课程是培养学生素质的重要环节,对提高仪器分析教学质量有着重要作用。本文分析了仪器分析实验课程的特点和教学现状,总结了实际教学过程中的各种改革措施,并就网上预习制度、小循环教学模式、开放实验室、穿插对比教学、增添条件实验、合理编排实验教材等方面进行了论述。实践证明,这些改革实践对仪器分析实验的课堂教学质量的提高,以及学生综合素质的培养十分有利。     

天然气处理工艺适应性分析

天然气是我国一种十分重要的能源,而且是一种包含多组分的混合型气体,烷烃是其中的主要成分,而且甲烷也占有较大的比例。在标准情况下天然气当中包含丁烷、丙烷和乙烷等物质,而且还包含水、硫化氢和二氧化硫等物质。天然气在储藏过程中具有较强的致命性,由于地质相对复杂,所以分析预测工作也相对困难,通常拥有低渗和低压等多种特点。目前我国油田行业发展速度较快,而且规模在不断扩大,天然气工艺具有一定的安全性和合理性,是当前行业发展的重要导向。因此,本文针对天然气处理工艺适应性进行分析和研究,以此来推动对天然气行业的发展。     

仪器分析实验的现状分析

仪器分析是一种重要的科学检验手段,其涉及各个行业、领域。仪器分析实验是为了让学生更好的理解仪器分析的内容而开设的一门课程,它可以帮助学生消化、理解抽象的仪器分析理论知识,提高学生运用基本理论分析解决问题的能力,促进学生的知识、技能向研究能力转化。通过仪器分析实验的训练,学生能够掌握各种常见仪器的使用方法,以及一些简单的实验测定。     

Bubble point pressures and densities of hexamethyldisiloxane–carbon dioxide binary mixture using a constant volume view cell

The phase behavior of hexamethyldisiloxane (HMDS)–carbon dioxide (CO₂) binary mixture was investigated using a constant volume view cell. The accuracy of the measurement technique was inspected against the bubble point pressure data in the literature for ethanol (C₂H₅OH)–carbon dioxide (CO₂) binary mixture. The bubble point pressures for C₂H₅OH–CO₂ agreed well with the literature values. The bubble point pressures of HMDS–CO₂ binary mixture were determined at five different temperatures (T = 298.2 K, 308.2 K, 313.2 K, 323.2 K, 333.2 K) and at various compositions. The bubble point pressures increased with increasing temperature and CO₂ mole fraction in the binary mixture. The phase behavior of the binary mixture was modeled using the Peng–Robinson Stryjek–Vera equation of state (PRSVEoS). The binary interaction parameters were regressed from experimental bubble point pressures at each temperature and were found to exhibit a linear dependency on temperature. The HMDS–CO₂ binary mixture was also found to exhibit Type II phase behavior. Additionally, P–T–ρ measurements for the same binary system were conducted and excess molar volumes were calculated.     

六甲基二硅氮烷对硅溶胶接枝改性的研究

采用六甲基二硅氮烷(HMDS)在酸性条件下对硅溶胶(SiSols)进行接枝改性。对接枝产物进行了分离提纯并研究了HMDS/SiSol(s摩尔比)、反应温度和反应时间对接枝率的影响。结果表明:在酸催化条件下HMDS可以对SiSols实现表面接枝改性;当控制HMDS与SiSols摩尔比为5颐10、反应温度为35℃、反应时间为2h时,接枝率达到最大值。     

Flame synthesis of titania particles from titanium tetraisopropoxide in premixed flames

An experimental investigation of flame synthesis of titania particles was conducted in premixed flames. The titanium precursor and silicon dopant used in this study were titanium tetraisopropoxide (TTIP) and hexamethyldisiloxane (HMDS), respectively. The objective of this study was to investigate the influence of flame condition, TTIP concentration, and HMDS on the phase composition and particle morphology of titania synthesized in flames. It was found that the anatase content of titania particles made in flames was appreciably increased by the increase of oxygen concentration in the oxidizer. The increase of flame temperature results in the decrease of anatase content. A significant increase in rutile content of titania particles was observed by increasing the particle residence time at high temperatures. The doping of HMDS in flames inhibits the transformation of anatase to rutile phase and, therefore, reduces the rutile content of product particles. Under the flame doped with low concentrations of HMDS, titania particles with SiO₂ particle agglomerates attached were produced. Further increase of the HMDS concentration up to the Si to Ti molar ratio equal to 0.375 results in the formation of a large amount of SiO₂ agglomerates in the product.     

硅烷偶联剂在气相白炭黑表面处理中的应用研究

本文考察了几种不同硅烷偶联剂对气相白炭黑的表面处理效果.对处理前后的气相白炭黑作了FT-IR分析,并用正交试验法考察了处理剂类型、处理时间及处理温度对产品疏水性的影响.结果表明,用18％的HMDS作处理剂,将气相白炭黑在90℃条件下处理4h,所得的疏水性气相白炭黑能很好改善RTV-2硅橡胶的工艺性能和力学性能;另外,采用胶料中直接混合的方式HMDS也能有效改善胶料工艺性能.     

Enhanced photo-sensitivity through an increased light-trapping on Si by surface nano-structuring using MWCNT etch mask

We demonstrate an enhanced photo-sensitivity (PS) through an increased light-trapping using surface nano-structuring technique by inductively coupled plasma (ICP) etching on multi-walled carbon nanotube (MWCNT) etch masked Si with hexamethyl-disilazane (HMDS) dispersion. In order for a systematic comparison, four samples are prepared, respectively, by conventional photolithography and ICP etching using MWCNT as a etch mask. MWCNT-etched Si with HMDS dispersion shows the highest RMS roughness and the lowest reflectance of the four. Two test device structures are fabricated with active regions of bare-Si as a reference and MWCNT etch masked Si with HMDS dispersion. The increased light-trapping was most significant at mid-UV, somewhat less at visible and less noticeable at infrared. With an ICP-etched Si using CNT HMDS dispersion, PS is very sharply increased. This result can lead to applications in optoelectronics where the enhancement in light-trapping is important.     

机械化学法改性纳米SiO_2粒子(英文)

利用机械化学法对纳米SiO2进行了表面修饰改性。首先通过高速机械冲击将纳米SiO2粒子镶嵌在微米级的CaCO3粒子表面形成草莓结构的CaCO3/SiO2复合粒子,从而阻止纳米SiO2的团聚。而后又以六甲基二硅氮烷(hexmethyldisilazane,HMDS)和γ-氨丙基三乙氧基硅烷KH550为改性剂对CaCO3/SiO2复合粒子进行了表面改性。用红外光谱和热重分析对复合粒子进行了表征与分析。考察了搅拌速度、CaCO3/SiO2配比、改性温度、改性时间和改性剂用量对CaCO3/SiO2复合粒子形貌和表面改性效果的影响。结果表明:在搅拌速度为6500r/minCaCO3与SiO2的质量比为5:1,以HMDS为改性剂在200℃反应90min时,对纳米SiO2的改性效果最好。CaCO3/SiO2复合粒子既保持了纳米SiO2的纳米效应,同时又具有多重表面结构,在橡胶补强填料和超疏水涂层制备方面有着广阔的应用空间。     

In-Situ FTIR Kinetic Study in the Silylation of Low-k Films with Hexamethyldisilazane Dissolved in Supercritical CO2

In-situ Fourier transform infrared spectroscopy measurements were obtained by using an innovative equipment to study the heterogeneous reaction between a hydrolyzed porous methylsilsesquioxane film and hexamethyldisilazane (HMDS) dissolved in CO₂ at supercritical conditions. Gas and solid infrared signatures were separated to obtain kinetic information of the heterogeneous reaction. A two-step reaction mechanism was observed: a fast first step controlled by kinetics and a second step controlled by the diffusion of the HMDS inside the porous material. Infrared information was used to derive a rate law expression of the silylation reaction between HMDS and Si-OH. A first order of reaction relative to the concentration of hydrophilic sites was observed with activation energy of 51.85 ± 1.25 kJ/mol.     

六甲基二硅胺烷作为锂离子电池电解液稳定剂的研究

研究了六甲基二硅胺烷(HMDS)作为锂离子电池电解液的稳定剂对电解液稳定性和电化学性能的影响.将两种不同的电解液经过60℃/24h高温储存,取样分析检测电解液的H<,2>O和HF的含量变化,并用两种不同的电解液制作电池进行85℃/4h高温储存和电化学性能测试.结果表明,HMDS的加入明显提高了锂离子电池电解液的储存稳定...     

Preparation of HMDS-modified silica/polyacrylate hydrophobic hard coatings on PMMA substrates

Colloidal silica nanoparticles synthesized from tetraethoxysiliane via a sol–gel process were surface modified by 3-(trimethoxysilyl)propyl methacrylate (MSMA) and 1,1,1,3,3,3-hexamethyldisilazane (HMDS). MSMA acted both as a C=C provider and a coupling agent, whereas HMDS was used to prevent particle aggregation and engender hydrophobicity. The modified silica particles (HMSiO₂) were UV-cured together with the crosslinking agent, dipentaerythritol hexa-acrylate (DPHA) to form coatings on poly(methyl methacrylate) (PMMA) substrates. Dynamic light scattering of the synthesized sols indicated that the average size of HMSiO₂ was ca. 10 nm, consistent with that obtained from TEM imaging. FTIR spectroscopic analyses demonstrated chemical attachment of HMDS to the silica particles. The cured coatings were characterized in terms of water contact angle, light transmittance, hardness, abrasion resistance, and surface morphology. It was found that hydrophobicity of the coatings increased while light transmittance and hardness decreased with increasing HMDS content. DPHA played the role of providing mechanical strength and adherence; however, the coatings became lightly hazy when the weight ratio of DPHA/silica fell in the range 0.3–0.7. In the optimal case, a hard coating (4H) with water contact angle of 108° and transmittance of ~100% (vs PMMA) had been obtained at the DPHA content of 10 wt%.     

Improvement of the adhesion of silicone to aluminum using plasma polymerization

The adhesion-in-peel test was used to determine peel strength and adhesion characteristics of a cured-in-place silicone elastomeric joint sealant on aluminum substrates. The sealant used was a Dow Corning Type 3145 RTV Adhesive Sealant. The results showed that the silicone sealant had poor adhesive bonding to the untreated aluminum. Plasma polymerization of hexamethyldisiloxane (HMDS) onto the aluminum was seen to move the locus of adhesive failure to being between the plasma film and the silicone. Plasma polymerization of HMDS with oxygen carrier gas produced excellent adhesion and cohesive failure in the silicone was observed.