PID仪表检测粘胶纤维生产中CS2气体浓度的探讨

介绍了光离子化气体传感器PID仪表检测原理与检测CS2气体浓度的方法,分析了待测气体中含有硫化物及挥发性有机物(本文以H2S、异丁烯为例)时对CS2浓度检测准确度的影响.采用PID仪表在CS2气体进行在线监测,低电离电位、低校正系数气体的存在会导致检测结果偏高.     

光谱吸收法测定气体中的CO_2含量

光谱吸收式光纤气体检测技术的基本原理,采用CO_2检测系统进行实验研究,建立了光强与电压幅值之间的关系曲线,对气体中的CO_2浓度进行检测。结果表明,该方法对0~1%的CO_2浓度具有很好的敏感性和准确性,为提高光谱吸收式检测系统的精度,拓展其实际应用打下良好基础。     

基于LabVIEW平台的通用激光吸收光谱系统设计

基于LabVIEW平台,开发了一套通用的基于可调二极管激光吸收光谱(TDLAS)的气体检测系统。整个系统在GPIB总线技术基础之上,构架了由锁相放大器、信号发生器、激光驱动器、可调谐激光器、工控机等组成的硬件平台,并开发了相应的控制程序和数据采集处理方法,设置了配套的人机交互界面。在TDLAS实验中,使用1.58μm的DFB激光器,在光程100m的情况下,对实验室内的CO2气体进行了抽取式检测,测得实验室环境下的CO2气体浓度略高于大气,系统灵敏度为2×106,实现了检测气体浓度的功能。该系统是一个通用的TDLAS检测平台,通过更换不同波长的激光器,可以对不同的目标气体进行分析,对TDLAS的实验研究和现场环境检测都有重要意义。     

农药中挥发性溶剂的气体检测方法研究

根据农药溶剂中挥发性气体的特性,选用定制的plot毛细管色谱柱与中等极性毛细管色谱柱作为分离系统,利用气体传感器进行浓度识别,对农药溶剂中的挥发性气体进行分析检测。设计制作了预处理系统完成样品气体的采集与进样,通过色谱系统进行分析检测。针对农药溶剂挥发性气体:乙醇、丙酮、异丙醇、乙酸乙酯、苯和甲苯的混合气体进行检测,苯的检测体积分数可以达到1×10^-6,乙醇的检测体积分数可以达到2×10^-6。     

可燃气体检测报警器的检定及常见故障

<正>随着石油、化工行业生产安全问题的日益突出,可燃气体检测报警器在石油、化工等行业安全生产中发挥着越来越重要的作用,同时因其可以实时监测可燃气体的浓度,当可燃气体浓度超过设定浓度时就会启动报警设备,因而被广泛应用于各种生产与生活场所。作为强制检测计量器具,可燃气体检测报警器按照自身安装形式可以划分为固定式和便携式;按照使用环境划分为工业用和民用;按照检测方式可以划分为催化燃烧式、气敏半导体式、红外线吸收式。目前,催化燃烧式可燃气体检测报警     

工业制SO3气体浓度实时检测及多元非线性回归建模

工业接触法制SO₃气体浓度高、腐蚀性强、交叉影响大，高精度实时检测困难，且原料流量与SO₃浓度的关系尚不明确，参数调节依赖经验。针对上述问题，采用AO2电化学氧传感器设计了一种工业制SO₃气体浓度的实时检测系统，并构建了输入空气、SO₂流量与输出SO₃浓度的多元非线性回归模型。SO₃气体浓度实时检测系统主要包括AO2电化学氧传感器、传感器调理电路、AD620放大电路及ADS1256 A/D转换电路，通过检测SO₃发生装置输入空气与输出混合气体中O₂浓度的毫伏级变化，间接测量SO₃浓度，避免了其他敏感气体的交叉影响，实验结果表明检测系统的检测时间为27s，灵敏度为111mV/%，偏差小于0.18%，稳定性良好，证明了检测系统的有效性；利用响应面法建立了预测SO₃浓度的三次多项式非线性回归模型，对该模型进行方差分析后结果显著，测试后均方误差（MSE）为0.0007174，相关系数（R²）为0.9929，拟合度好、预测精度高。     

基于FTIR的GIS气室中SF6分解产物SO2 F2的检测

硫酰氟(SO_2F_2)气体是全封闭组合电器(GIS)中SF_6气体分解产物的重要特征组分之一,基于SO_2F_2气体成分的检测可实现高压电器设备潜伏性故障类型的识别,因此快速准确实现GIS气室中SO_2F_2组分的检测具有重要意义。采用温、压可调多次反射长光程池,基于傅里叶变换红外光谱仪(FTIR)技术建立SO_2F_2/SF_6气体实验分析平台,在高纯SF_6背景下对痕量SO_2F_2气体谱线进行交叉干扰分析,最终选取中心波长1 503 cm~(-1)(6.65μm)处作为定性依据,利用质量比混合法及动态配气仪制备4个梯度浓度SO_2F_2/SF_6标准样品,建立了定量分析的标准曲线,并对质量比混合法制备的100～400μL/L的SO_2F_2/SF_6混气样品进行浓度反演分析。结果表明:在100～400μL/L浓度范围内,校正面积拟合曲线优于校正高度拟合曲线,线性拟合常数R~20.99,可实现SO_2F_2/SF_6混气中SO_2F_2气体的快速检测,样品浓度反演结果显示误差均小于2%。该研究可提供一种SO_2F_2/SF_6混合气体制备方法,并为GIS气室中SF_6分解产物SO_2F_2含量的检测提供一种切实可行的光学方法。     

基于TDLAS技术的甲烷气体浓度识别系统

以不同浓度的甲烷气体为研究对象,利用甲烷在1653.7nm处的吸收峰,搭建基于TDLAS技术的甲烷气体浓度识别系统,利用Matlab软件拟合不同配比甲烷气体浓度曲线,并用其他标准浓度气体进行精度验证.搭建的基于TDLAS技术的甲烷浓度识别系统由气体浓度配比、光电检测和信号采集处理3部分组成.使用高精度流量计,利用高纯氮...     

半导体激光分析仪在催化裂化烟气分析上的应用

一、催化裂化中再生烟气的O2、CO和CO2检测目的及需求（1）测量气体为O2、CO、CO2。通过对再生反应烟气中CO、CO2和O2浓度的分析，     

可燃气体报警器计量检定与计量管理的探讨

可燃气体检测报警器是《中华人民共和国计量法》确定的强制检定的计量器具,广泛应用于石油化工、气体充装、城镇燃气及仓储。当工业环境中可燃气体泄漏时,可燃气体检测报警器（以下简称为报警器）的检测器检测到气体浓度达到爆炸或中毒浓度设置的临界点时,报警器的控制器就会发出报警信号,以提醒使用单位迅速采取驱动排风、切断、     

Insect antifeedant properties of anthranoids from the genusVismia

Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.     

Direct observation of freeze-thaw instability of latex coatings via high pressure freezing and cryogenic SEM

Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.     

Ethanol and (−)-α-Pinene: Attractant Kairomones for Bark and Ambrosia Beetles in the Southeastern US

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.     

Methyl 2,4,6-decatrienoates Attract Stink Bugs and Tachinid Parasitoids

Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.     

2007～2008年世界塑料工业进展

收集了2007年7月～2008年6月世界塑料工业的相关资料,介绍了2007～2008年国外塑料工业的发展情况,提供了世界塑料产量、消费量及全球各类树脂的需求量及产能情况.按通用热塑性树脂(聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂)、工程塑料(尼龙、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚)、特种工程塑料(聚苯·硫醚、液晶聚合物、聚醚醚酮)、通用热固性树脂(酚醛、聚氨酯、不饱和聚酯树脂、环氧树脂)不同品种的顺序,对树脂的产量、消费量、供需状况及合成工艺、产品应用开发、树脂品种的延伸及应用的进一步扩展等技术作了详细介绍.     

2005～2006年国外塑料工业进展

收集了2005年7月～2006年6月国外塑料工业的相关资料,介绍了2005—2006年国外塑料工业的发展情况。提供了世界塑料产量、消费量及全球各类树脂生产量以及各国塑料制品的进出口情况。作为对比,介绍了中国塑料的生产情况。按通用热塑性树脂（聚乙烯、聚丙烯、聚苯乙烯、聚氯乙烯、ABS树脂）、工程塑料（聚酰胺、聚碳酸酯、聚甲醛、热塑性聚酯、聚苯醚）、通用热固性树脂（酚醛、聚氨酯、不饱和树脂、环氧树脂）、特种工程塑料（聚苯硫醚、液晶聚合物、聚醚醚酮）的品种顺序,对树脂的产量、消费量、供需状况及合成工艺、产品开发、树脂品种的延伸及应用的扩展作了详细的介绍。