火焰原子吸收光谱法测定茶叶中的铅

用火焰原子吸收光谱法测定了茶叶中铅含量，在一定的条件下，茶叶样品的铅可不经MIBK萃取分离而直接用火焰原子吸收光谱法进行测定，测定结果令人满意。     

石墨炉蒸发硫化铟双原子分子吸收光谱法测定硫

本文对硫化铟双原子分子吸收光谱法测定硫进行了系统的研究。通过实验,确定了硫化铟双原子分子吸收光谱法测硫的最佳操作条件,并对某些实际样品进行了分析。     

微波消解-火焰原子吸收光谱法测定海藻中的微量元素

利用微波消解-火焰原子吸收光谱法(FAAS)测定了大连产5种海藻样品中Zn、Fe、Cu、Mn 4种微量元素的含量.对微波消解条件和原子吸收光谱测定的条件进行了优化.实验结果表明,微波消解法操作简便快速、样品消解完全,空白值低、环境污染小;火焰原子吸收光谱方法选择性好,准确度高,回收率为91%-105%.样品测定结果显示...     

电感耦合等离子体发射光谱法测定烟道灰中的铟

铟是一种银白色稀有稀散金属,在地壳中的平均质量分数为0.000 01%,为了准确测定烟道灰样品中低含量的铟,通过对样品成分的初步分析,确定实验中溶解样品所用的酸及其比例。依次逐步加入HCl, HNO3, HF和HClO4(V∶V∶V∶V=15∶5∶2∶2),将样品完全溶解后,冷却至室温并移入分液漏斗,在HBr介质中,以溴化铵做盐析剂(溶液体积控制在25 mL左右);移取25 mL乙酸乙酯作为萃取剂和稀释剂,萃取液直接导入配备有机进样系统的电感耦合等离子体原子发射光谱仪(ICP-AES),选择In 230.606 nm为分析谱线,对烟道灰样品中的铟进行测定,从而建立了电感耦合等离子体原子发射光谱法(ICP-AES)测定烟道灰样品中铟的方法。实验样品溶解后,采用萃取分离法消除基体元素及共存元素的干扰。通过对萃取酸度、萃取剂、萃取方法、盐析剂、分析谱线等条件试验,确定了最优的实验条件。铟的质量浓度在0.25~4.00 mg·L^-1范围内与其发射强度呈线性关系,校准曲线线性相关系数为0.999 3,检出限为0.03 mg·L^-1,测定结果的相对标准偏差(n=11)小于5%,回收率在92%~102%之间。按照上述试验步骤测定5个烟道灰样品中的铟含量,其测定结果与ICP-MS法比较吻合。另外,与现有的分析方法(EDTA滴定法、分光光度法、原子吸收光谱法、 X射线荧光光谱法、电感耦合等离子体原子发射光谱法及质谱法等)相比,该法具有简便,快速,灵敏,准确度较高的优点,可用于铟含量在0.000 8%~0.10%之间烟道灰样品的批量检测。     

单缝石英管火焰原子吸收法测定大米中微量铜

本文根据文献报道使用单缝石英管火焰原子吸收法提高火焰原子法的灵敏度,对大米中微量铜的测定进行研究。方法简单、快速,文献尚未见报道。由实验得到了比较满意的分析结果,回收率为96～102%。变异系数为1.9%,灵敏度可提高3倍。     

三正辛胺棉富集分离原子吸收光谱法测定金

论述了三正辛胺棉的制备及吸附金的条件和解脱方法。采用火焰原子吸收法进行测定。方法的测定范围为0.2-40g/t，相对标准偏差为2.3%，将该法用于制定黄铜矿中的金，其结果与传统的泡沫塑料富集-硫脲解脱原子吸收法测定结果一致，而本法分离效果好，测定速度快，操作简便。     

计算原子吸收法间接测定钒

本文研究了用空气－乙炔火焰原子吸收法间接测定钒一种计算分析方法，利用钒对原子吸收法测定铬时的干扰效应，以多项式作为表面其干扰效应的数学模型，在已知铬含量的铬钒混合液中测定铬的吸光度，并从数学模型中解出钒的浓度，从而间接测定了钒。     

氢化物原子吸收与常规雾化火焰原子吸收法测定锑的几个问题

本文就氢化物原子吸收法与常规雾化火焰原子吸收法用于锑含量的测定中所存在的共存元素的干扰,"记忆效应"及锑的价态变化等几个方面的问题进行了试验考察和分析,对两种方法的灵敏度、精密度及测定线性范围进行了比较,结果表明:氢化物原子吸收法的最大优点是灵敏度高(可达pp～b级)能满足含有微量锑试样的分析要求。雾化火焰原子吸收法测定锑,由于不存在"记忆"效应,样品之间的更换瞬间即可完成,因而适宜大量样品的检测分析。     

火焰发射光谱法测定碱金属元素的研究

本文研究了火焰发射光谱法测定钾、钠等碱金属元素的各种测定条件，选择其最佳条件。通过标准样品的测定，试验了该方法的准确度、精密度、直接可测定的浓度范围、检出限以及不同燃烧器对测定的影响。试验结果表明，浓度范围在0.5－46微克／毫升时，回收率为97－102％；同一试样分别称样10次测定结果，其标准偏差为0.0049；浓度范围为0－50微克／毫升时，校准曲线呈直线，而用原子吸收方法，大约至5微克／毫升浓度时校准曲线已开始弯曲，火焰发射光谱法可节省空心阴极灯，从而使测定更简便快速。因此，火焰发射光谱测定碱金属元素比原子吸收光谱法更优越。     

混合酸消解-原子吸收光谱法测定凡士林中铅和镉

本文通过HNO3-HF-HClO4混合酸消解法对凡士林样品进行前处理，采用火焰原子吸收光谱法同时测定微量铅和镉，并与其他前处理方法进行比较。该法简便快速、准确实用，具有较高的精密度和回收率。     

Investigations of morphology, purity and crystal defects of the InN pillar crystals prepared by means of halide chemical vapor deposition under atmospheric pressure

Indium nitride prepared under atmospheric pressure using a halide chemical vapor deposition method has been examined by means of a variety of analytical techniques. Scanning electron microscopic observations showed that the crystals deposited onto a Si(100) substrate have hexagonal pillar structure. Based on the X-ray diffraction and X-ray pole-figure analyses, it was deduced that each InN pillar crystal grows with a different rotation angle around the 〈001〉 axis. Transmission electron diffraction showed that they are of single-like form. This was also confirmed by the selected area electron diffraction image as well.     

ITO前驱物氢氧化铟In(OH)Zr3理论研究

分析了铟锡氧化物IT0（Indium Tin Oxide）前驱体氢氧化铟In(OH)3的结构，理论计算了其马德隆常数和晶格能,其值分别为2.9488和-5095.21kJ/mol, 并给出了晶核表面自由能近似公式和晶核生长率的近似表达式,进而计算了采用化学沉淀法制备In(OH)3纳米粉末时的晶核形成参数, In(OH)3晶核生长初期的生长率约为0.012nm/s. 关键词： 纳米粉末 In(OH)3 表面自由能 晶核生长     

ITO前驱物氢氧化铟In(OH)3理论研究

分析了铟锡氧化物IT0 (IndiumTinOxide)前驱体氢氧化铟In(OH) 3的结构 ,理论计算了其马德隆常数和晶格能 ,其值分别为 2 94 88和 - 5 0 95 2 1kJ mol,并给出了晶核表面自由能近似公式和晶核生长率的近似表达式 ,进而计算了采用化学沉淀法制备In(OH) 3纳米粉末时的晶核形成参数 ,In(OH) 3晶核生长初期的生长率约为 0 0 1 2nm s.     

退火及铟含量对InGaAs量子点光学特性的影响

 研究了退火条件和In组份对分子束外延生长的InGaAs量子点（分别 以GaAs或AlG aAs为基体）光学特性的影响。表明：量子点中In含量的增加将导致载流子的定域能增加和基态与激发态之间的能量间隔增大。采用垂直耦合的量子点及宽能带的AlGaAs基体可增 强材料的热稳定性。以AlGaAs为基体的InGaAs量子点,高温后退火工艺 (T= 830℃)可改善低温生长的AlGaAs层的质量,从而改善量子点激光器材料的质量。     

Synthesis of low-melting-point metallic nanoparticles with an ultrasonic nanoemulsion method

A one-step, economical nanoemulsion method has been introduced to synthesize low-melting-point metallic nanoparticles. This nanoemulsion technique exploits the extremely high shear rates generated by the ultrasonic agitation and the relatively large viscosity of the continuous phase - polyalphaolefin (PAO), to rupture the molten metal down to diameter below 100 nm. Field’s metal nanoparticles and Indium nanoparticles of respective average diameters of 15 nm and 30 nm have been obtained. The nanoparticles size and shape are determined by transmission electron microscopy (TEM). Their phase transition behavior is examined using a differential scanning calorimeter (DSC). It is found that these nanoparticles dispersed in PAO can undergo reversible, melting-freezing phase transition, and exhibit a relatively large hysteresis. The experimental results suggest that the nanoemulsion method is a viable route for mass production of low-melting nanoparticles.     

Characterisation of InAs/GaAs short period superlattices using column ratio mapping in aberration-corrected scanning transmission electron microscopy

The image processing technique of column ratio mapping was applied to aberration-corrected high angle annular dark field (HAADF) images of short period MBE (molecular beam epitaxy) grown InAs/GaAs superlattices. This method allowed the Indium distribution to be mapped and a more detailed assessment of interfacial quality to be made. Frozen-phonon multislice simulations were also employed to provide a better understanding of the experimental column ratio values. It was established that ultra-thin InAs/GaAs layers can be grown sufficiently well by MBE. This is despite the fact that the Indium segregated over 3-4 monolayers. Furthermore, the effect of the growth temperature on the quality of the layers was also investigated. It was demonstrated that the higher growth temperature resulted in a better quality superlattice structure.     

Effect of annealing on photo accelerated chemically deposited Indium sulfide thin films with various cationic precursors

The present work reports the deposition of Indium sulfide thin films by a recently established novel method called photo-assisted chemical deposition technique. It is a very low cost method for the deposition of thin films, and can be easily scaled up for industrial production. Indium sulfide thin films are deposited on glass substrates through various cationic precursors and the effect of annealing on structural, optical and morphological properties was investigated. Films have been characterized with respect to their structural, optical and morphological properties by means of X-ray diffraction, UV–VIS-NIR Spectrophotometer, SEM and AFM techniques. As-deposited films on glass substrates were amorphous and became crystalline after annealing. The grain size of all the annealed films are larger than the as-prepared films and attained a maximum value for the film prepared with sulfate precursor. The calculated strain was compressive in nature. Surface roughness was estimated from the AFM measurements and found to be decreased in annealed samples. The film deposited with chloride precursor showed a higher visible transmittance of around 80 % and became 90 % on annealing. The variation of packing density follows the variation of the refractive index. The optical band gap of the samples was estimated and found to be within the range of 2.45–2.71 eV, which is in quite agreement with the literature.     

Indium and tin oxide polycrystalline thin films as NO gas sensors produced by reactive pulsed laser ablation and deposition

Pulsed laser ablation is a very interesting method of depositing thin films of several materials and compounds, such as oxides, nitrides, insulators, semiconductors, and superconductors. Indium and tin oxide polycrystalline thin films have been grown on silicon (100) substrates by reactive PLD from two metallic targets of indium and tin by multilayered deposition, in the presence of oxygen, using a frequency-doubled Nd-YAG laser (5=532 nm). The films produced have been studied to evaluate their use as NO gas sensors, and the best performance has been found by varying some important parameters, such as the substrate temperature and the pressure of oxygen in the deposition chamber. X-ray diffraction analysis of the deposited films shows that they are polycrystalline with a preferential (400) orientation. Electrical resistivity measurements, performed by using a four-point probe technique, show a sharp increase in resistivity when the films are exposed to NO. The electrical responses of tin oxide-indium oxide multilayered thin films are reported.     

A method used to overcome polarization effects in semi-polar structures of nitride light-emitting diodes emitting green radiation

Polarization effects are studied within nitride light-emitting diodes (LEDs) manufactured on standard polar and semipolar substrates. A new theoretical approach, somewhat different than standard ones, is proposed to this end. It is well known that when regular polar GaN substrates are used, strong piezoelectric and spontaneous polarizations create built-in electric fields leading to the quantum-confined Stark effects (QCSEs). These effects may be completely avoided in nonpolar crystallographic orientations, but then there are problems with manufacturing InGaN layers of relatively high Indium contents necessary for the green emission. Hence, a procedure leading to partly overcoming these polarization problems in semi-polar LEDs emitting green radiation is proposed. The (1122) crystallographic substrate orientation (inclination angle of 58^° to c plane) seems to be the most promising because it is characterized by low Miller–Bravais indices leading to high-quality and high Indium content smooth growth planes. Besides, it makes possible an increased Indium incorporation efficiency and it is efficient in suppressing QCSE. The In_0.3Ga_0.7N/GaN QW LED grown on the semipolar (1122) substrate has been found as currently the optimal LED structure emitting green radiation.     

Extension of the 106 samples Fourier spectrometry to the Indium Antimonide region: Vibration-rotation bands of 14N216O: 3.3–5.5 μm region

The high-information Fourier interferometer built at Laboratoire Aimé Cotton has been modified in order to extend the spectral range. It is now possible to record spectra in the Indium Antimonide region with an apodized resolution of 5 × 10^?3 cm^?1. Nitrous oxide vibration-rotation bands between 1800 and 3200 cm^?1 have been measured and analyzed and rotational constants for 33 bands have been calculated.