动力学光度法测定痕量铑的研究

在磷酸介质和９０℃水浴中加热的条件下,痕量铑（Ⅲ）能灵敏地催化高碘酸钾氧化二安替比林对二乙氨基苯基甲烷（ＤＡＥＡＭ）的显色反应。研究了该催化反应的最佳实验条件及动力学参数,建立了一种动力我度法测定痕量铑的新方法。方法的线性范围为２０－１４０μｇ／Ｌ;检出限为２．０＊１０＾－８ｇ／ｍＬ,催化反应的表观活性能为９４．３０ｋＪ／ｍｏｌ,表观速率为１．５６＊１０＾－４／。本法已用于某些贵金属溶液中的铑的测定,其相对标准偏差为３．１％－３．４％,加标回收率为９８．３％－９９．４％。     

火焰原子吸收法同时测定地质样品中金和银

二氯化锡还原，二氯化汞共沉淀，火焰原子吸收法同时测定地质样品中金和银。对于原矿和尾矿样品，金含量为５．１５μｇ／ｇ，４．４５μｇ／ｇ和０．５４μｇ／ｇ时，相对标准偏差分别为６．２％，３．４％和４．１％。银含量为９．７８μｇ／ｇ和１．２２μｇ／ｇ时，相对标准偏差分别为４．４％，３．５％和１２．５％。金的分析结果与参考值基本一致。金和银的回收率分别为８８－１０２％和８５－１００％。方法具有干扰小，分离     

光谱—电化学法对铁,铅的测定方法研究

在０．１５ｍｏｌ／ＬＨＡｃ－ＮＨ４Ａｃ支持电解质中，使用０．１ｇ／Ｌ的邻菲罗啉（ｏ－Ｐｈｅｎ）采用经典极谱仪测定其离子络合物吸附波，分光光度法测定铁离子，检出下限分别达到：铅离子为１．５０×１０＾－１０ｍｏｌ／Ｌ，铁离子为３．５８１×１０＾－７ｍｏｌ／Ｌ。该方法在回收率为９９．２％－１００．４％之间，具有较好的选择性。     

光谱－电化学法对铁、铅的测定方法研究

在０．１５ｍｏｌ／ＬＨａｃ－ＮＨ_４Ａｃ支持电解质中，使用０．１ｇ／Ｌ的邻菲啉（ｏ－Ｐｈｅｎ），采用经典极谱仪测定其铅离子络合物吸附波，分光光度法测定铁离子，检出下限分别达到：铅离子为１．５０×１０（－１０）ｍｏｌ／Ｌ，铁离子为３．５８１×１０（－７）ｍｏｌ／Ｌ。该方法的回收率为９９．２％－１００．４％之间，具有较好的选择性。     

荧光法直接测定环境中邻羟基苯甲酸和苯酚混合物的含量

本文研究了用荧光分光度法测定环境水中苯酚和邻羟基苯甲酸的含量碘在ＰＨ〉１１时直接测定邻羟基苯甲酸的含量,波长为λｅｘ／λｅｍ＝２８９／３３８ｎｍ,检出 为３．４ｎｇ／ｍＬ,线性范围０－６．０μｇ／ｍＬ。在ＰＨ＝６,波长为λｅｘ／λｅｍ＝２７０／２９７ｎｍ测得苯酚含量,检出限为４．０ｎｇ／ｍＬ,线性范围在０－０．８５μｇ／ｍＬ,回收率为９８－１０１％,,结果满意。     

钨盐涂覆-GFAAS法测定肿瘤患者体内痕量锂

钨盐涂覆处理石墨管,大幅度提高测定锂的灵敏度。配以（ＮＨ４）２ＳＯ４基体改进剂,消除生物基体干扰。特征浓度５．５３×１０－３μｇ·ｍＬ－１／１％,回收率大于９３．７２％,相对标准偏差小于８．９３％。     

萃取分离-石墨炉原子吸收光谱法测定盐卤中痕量铯的研究

采用墨炉原子吸收光谱法（ＧＦＡＡＳ）研究盐卤中铯原子化行为和机理,建立了热解石墨管、ＫＮＯ３－ＮＨ４ＮＯ３基体改进剂、１８－冠－６、溴百里香酚蓝、氯仿萃取分离－ＧＦＡＡＳ测定盐卤中铯的方法。用于测定盐卤中痕量铯,特征质量１．４×１０－１０ｇ／０．００４４Ａ;加标回收率８９％～１０５％;相对标准偏差４．１３％。     

酞菁钴/铁纳米填充母粒的制备及其稳定性

采用有机／无机原位复合技术,将酞菁钴（ＣｏＰｃ）的ＤＭＦ溶液与Ｆｅ（ＣＯ）５混合、加热回流制备出稳定的、规则球形的、平均粒径为１．４μｍ的酞菁钴／铁纳米填充母料。其内部为１０￣１５ｎｍ的α－Ｆｅ填充,外部为厚５０￣１５０的酞菁钴层包覆。纳米填充母粒的填３实密度为３．６６４ｇ／ｃｍ＾３,比饱和磁化强度为７６．３Ａｍ＾２／ｋｇ,矫顽力为４．１５ｋＡ／ｍ,纳米填充母粒的热稳定性高于１５０℃,与甲基硅油组     

气相色谱／石英炉（Ⅲ型）原子吸收光谱联用及烷基铅化学形态分析…

本文较系统地研究了色谱／原子吸收光谱联用的工作条件对测定烷基铅的影响，选择了分析条件，并对烷基铅样品进行了分离测定。分析结果的相对标准差为３．３１－４．１２％，回收率为９４．６－１０４．０％。     

微波溶样—ICP／MS法测定稻中15种痕量稀土元素

本文报道采用ＨＮＯ３＋Ｈ２Ｏ２微波溶样，ＩＣＰ－ＭＳ直接测定稻中１５种稀土元素，对微波溶样和等离子体质谱测定条件进行了优化选择。选用Ｒｅ作内标可补偿基体效应。方法检出限为７．０－２５．８ｐｇ／ｍＬ，稻壳加标回收率为９５－１０５％，ＲＳＤ为２．３－４．２％，方法快速、灵敏、准确。     

Major elements analysis in bituminous coals under different ambient gases by laser-induced breakdown spectroscopy with PLS modeling

Three major elements, carbon, hydrogen, and nitrogen, in twenty-four bituminous coal samples, were measured by laser-induced breakdown spectroscopy. Argon and helium were applied as ambient gas to enhance the signals and eliminate the interference of nitrogen from surrounding air. The relative standard deviation of the related emission lines and the performance in the partial least squares (PLS) modeling were compared for different ambient environments. The results showed that argon not only improved the intensity, but also reduced signal fluctuation. The PLS model also had the optimal performance in multi-element analysis using argon as ambient gas. The root mean square error of prediction of carbon concentration decreased from 4.25% in air to 3.49% in argon, while the average relative error reduced from 4.96% to 2.98%. Hydrogen line demonstrated similar improvement. Yet, the nitrogen lines were too weak to be detected even in an argon environment which suggested the nitrogen signal measured in air come from the breakdown of nitrogen molecules in the atmosphere.     

Effect of CO on Characteristics of AlGaN/GaN Schottky Diode

Pt Schottky diode gas sensors for CO are fabricated using A1GaN/GaN high electron mobility transistor（HEMTs）structure. The diodes show a remarkable sensor signal （3 mA, in N2, 2mA in air ambient） biased 2 V after 1% CO is introduced at 50℃. The Schottky barrier heights decrease for 36meV and 27meV in the two cases respectively. The devices exhibit a slow recovery characteristic in air ambient but almost none in the background of pure N2, which reveals that oxygen molecules could accelerate the desorption of CO and offer restrictions to CO detection.     

气相色谱法测定环境空气中的微量乙酸

以填充多孔聚合物聚苯乙烯的吸附采样管吸附环境空气中的微量乙酸,样品经自动热脱附仪解吸,用强极性的色谱柱分离,氢火焰离子化检测器检测,方法最低检出浓度为0.10mg/m3,相对标准偏差在5%以下,加标回收率在86.2%—105.2%之间。方法操作简便、快速,适用于环境空气中微量乙酸的监测,实际测定结果满意。     

Real-time detection of 13CH4 in ambient air by use of mid-infrared cavity leak-out spectroscopy

We report on spectroscopic real-time detection of (13)CH(4) in ambient air. Our measurements were carried out by means of cavity leak-out absorption spectroscopy employing a tunable cw laser in the mid-infrared spectral region near lambda = 3 mum. A CO laser in combination with tunable microwave sideband generation was used as the light source. Using a 50-cm-long ringdown cell with R = 99.98% mirrors, we achieved a detection limit of 290 parts in 10(12) (ppt) (13)CH(4) in ambient air (integration time, 100 s). The corresponding noise-equivalent absorption coefficient was 5 x 10(-9)/cm.     

基于带闪蒸器的空气源热泵热风机试验性能研究

本文针对带闪蒸器的空气源热泵热风机的性能进行了测试、对比及数据分析,研究结果表明,随着室外环境温度在7℃-20℃之间下降时,两款热泵耗电量都在逐渐增加,带闪蒸器的空气源热泵热风机相较普通空气源热泵热风机的COP下降有变缓趋势,当室外环境温度为-12℃时,带闪蒸器的空气源热泵热风机的COP为2.43,而普通空气源热泵热风机为2.30;在-20℃时,带闪蒸器的空气源热泵热风机COP为2.15,普通空气源热泵热风机COP已降至1.98;带闪蒸器的空气源热泵比不带闪蒸器的空气源热泵性能提高大概8.6%左右。     

空浴式汽化器基础传热问题及研究现状评述

对我国空浴式汽化器的研究和使用现状进行了评述;分析了空浴式汽化器涉及的流动沸腾、凝华结霜、自然对流等传热过程及各过程之间的相互耦合关系;提出了综合研究各传热过程及相互制约关系的新思路,拟在前期工作的基础上研究管内的汽液两相流及沸腾传热过程、管外的霜层生长及导热规律,以及翅片管内外的耦合传热规律.     

Emission properties of laser ablation of SnO2: Sb transparent conducting film and KTiOPO4 crystal

Optical emission spectra of Nd:YAG laser ablation of KTiOPO₄ (KTP) crystal and SnO₂:Sb transparent conducting thin film were recorded and analyzed in vacuum and in air. The integral intensities of spectral lines from laser-ablated KTP crystal were obtained as functions of distance from the target surface and laser power density in vacuum and in air. The ambient gas effects on pulsed laser ablation of target were discussed. We also performed laser ablation of SnO₂:Sb transparent conducting thin film in air and the electron temperature and full-width at half-maximum (FWHM) of atomic and ionic spectral lines in the plasma were quantified using Boltzmann plot method and Lorentzian fit, respectively. Integral intensities of atomic and ionic Sn spectral lines were also obtained as functions of distance from the target surface and laser irradiance. The intensity ratio of ionic and atomic Sn spectral lines as a function of laser power density was got which gives some information about the variation of ionization ratio with laser irradiance in the plasma produced by high-power laser.     

Effects of thermo-physical and flow parameters on the static and dynamic burning of a cigarette

Effects of thermo-physical and operating parameters influencing the combustion of a cigarette were systematically studied using a three-dimensional first-principles-based mathematical model. Thermo-physical properties include packing density and thermal conductivity of materials forming the packed bed in the cigarette, and operating parameters include ambient oxygen concentration, air flow rate through the cigarette, and the ambient cross flow. The model was first validated with the existing experimental data which provided a satisfactory result. Increasing the ambient cross flow while increasing the burn rate and temperatures in the cigarette column, decreases the delivery of gaseous products owing to air infiltration through the paper into the column and enhances diffusion of gases out of column. Reducing the oxygen concentration reduces the burn rate to a point at which burning would be extinguished during the smoldering step. Increasing the air flow monotonically increases the burn rate, temperature and delivery of products in a burning cigarette. While thermal conductivity in the range varied here (50% above and 50% below the base case) it did not significantly affect the outcomes of the burning process; decreasing the packing density increases the heat generated and solid and gas temperatures, and decreases the delivery of some gaseous products.     

Improvement of the scintillation properties of Gd3Ga3Al2O12:Ce,B single crystals having tailored defect structure

A novel approach is reported to minimize various defect centers in Ce doped Gd₃Ga₃Al₂O₁₂ single crystals to improve the scintillation properties. The crystals of Gd₃Ga₃Al₂O₁₂ codoped with 0.2 at% Ce and B (GGAG:Ce,B) have been grown in air and argon ambient using the Czochralski technique. The scintillation light output of crystals grown in Ar ambient was significantly increased after annealing the crystals in air. The measured light output of 60000 ph/MeV for annealed crystals is the highest value reported among this class of materials. As a consequence, the energy resolution at 662 keV gamma‐rays from a ¹³⁷Cs source was improved from 8% for the crystals grown in air to 6% for crystals grown in Ar and subsequently annealed in air. Further, the thermal quenching energy of photoluminescence (PL) emission was increased to be 470 meV for the annealed crystals. The thermoluminescence (TL) measurements suggest that the crystals grown in Ar ambient and post‐growth annealed in air may have a lesser concentration of trap centers which subsequently lead to the improvement in optical and scintillation properties leading to a superior detector performance. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

苏码罐采样预浓缩-GC-MS测定空气中的挥发性有机化合物

采用苏码罐采样技术,预浓缩系统与GC-MS联用,优化了系统的测试条件,建立了测定环境空气中41种挥发性物的监测方法.用于环境空气和室内空气的监测,结果令人满意.