用电解法评估纯铜和普通黄铜样品的质量

在用电解法采集纯铜和 普通黄铜样品时，根据样品的牌号确定样品的近似电化摩尔质量ｋ，选择合适的电解条件使电流效率为１００％，用Ｆａｒａｄａｙ定律ｍ＝ｋＩｔ计算采集样品的质量。     

取样量对润滑油中微量水分检测结果的影响

研究取样量对润滑油中微量水分测定结果的影响。基于卡尔·费休滴定法,在选定的测量条件下,用发生电极为有隔膜的自动库仑水分仪对基础油、有机热载体油、压缩机油、膨胀机油等新油和发动机油、汽轮机油、涡轮机油、压缩机油、齿轮油、液压油、导热油、船用油、电器绝缘油、风动工具油、金属加工油等在用油在0.1~2.0 g内各取9组不同质量的样品进行测定,得到了润滑油中微量水分准确测定所需的取样量。实验结果表明,新油取样量大于1.0 g,在用油取样量在1.0~1.5 g范围内,可以准确测定润滑油中微量水分含量。测定结果的相对标准偏差为0.83%~3.51%(n=10),样品加标回收率为95.0%~103.0%。在选择的取样量下,该方法具有良好的精密度、准确度,可连续测定多个样品,满足测定需求。     

改变相比/顶空气相色谱法测定变压器油中溶解气体的分配常数

采用改变相比/顶空气相色谱法测定了甲烷、乙炔、乙烯、乙烷和丙烷在变压器油中的分配常数。顶空瓶中的气体样品经石英毛细管送到气相色谱仪的六通进样阀样品管中,然后进行分离和定量。采用标准曲线法定量,通过测定5个不同相比时轻烃组分的顶空浓度,计算顶空浓度倒数与相比之间的线性回归方程,测定了20 ℃和50 ℃时烃类气体在变压器油中溶解气体的分配常数。除甲烷外,计算所得的分配常数与文献值基本吻合,油中溶解气体浓度的实验值与实际值之间的相对误差小于4.14%,表明用此方法可以测定不同温度下变压器油中溶解气体的分     

薄层棒色谱法研究 (FID直接扫描色谱定量法)

一、序言目前国内薄层色谱的定量方法,一般仍用手工操作,手续繁杂,所需时间也较长,应尽快生产国外已广泛使用的薄层扫描仪。但国外常用的薄层扫描仪,是根据被测物质的光学性质进行检测的。其使用性能随被测物质而异,结构也比较复杂,不易制造。1967年Padley提出了薄层棒火焰离子化检测器(FID)扫描仪,用表面涂吸附剂的ф0.9×200毫米的石英棒代替通常的薄层层析板,将样品点于棒端,按一般的薄层色谱法展开分离。展开后挥发除去展开剂,被分离的样品组份斑点留在棒上,然后直接通过FID的火焰进行定量分析。该仪器较过去的光学扫描仪具有结构及操作简单,制造较易,应用范围广及线性范围宽等特点。本文对薄层棒色谱法和FID扫描仪的操作方法和操作条件进行了研究。     

磷酸三乙酯改性HZSM-5沸石的活性及理论研究

采用XRD表征了水蒸气和磷联合改性的HZSM-5沸石分子筛的结构．通过NH3-TPD和N2吸附脱附研究了样品的酸性和比表面．采用正庚烷的裂化反应研究了样品的裂化活性，研究结果表明，磷改性样品与母体样品相比，经过水蒸气处理后显示出较高的酸量和正庚烷裂化活性．上述结果首次用模型簇和计算量子化学方法进行了解释．采用Gaussian94软件包和PM3半经验量子化学方法对模型簇进行了全优化和频率分析．计算结果显示磷改性后样品的脱铝补硅反应热大于母体样品脱铝补硅反应热，从而显示出磷对骨架的稳定化作用．     

石墨炉原子吸收光谱法测定不同镍环境下人眼晶状体的镍量

利用高灵敏度的石墨炉原子吸收光谱仪对来自不同镍环境和不同状态的40个人眼晶状体中的镍进行了测试。在测试中，采用了方便的HNO，消解法对样品进行预处理，通过实验比较测得普通石墨管对镍的特征质量是长寿命石墨管的4．6倍，然后用长寿命石墨管对各种样品的消解后获得的测试液进行镍的测定，由此得到每个人眼晶状体中的绦量。结果表明：正常人的透明晶状体中的镍量明显低于患有白内障人眼晶状体中的镍量；而与镍矿直接接触的白内障患者的晶状体中的镍量显著高于非直接接触镍矿白内障患者和一般白内障患者晶状体中的镍量。这种关联表明人眼晶状体中的镍元素可能是白内障的致病因素之一。     

用热重分析法研究煤液化油的催化加氢

本文用热重分析方法研究了煤液化油的催化加氢，系统地考察了热重分析的各种操作条件对煤液化油以及它与固体催化剂的混合样品的热重分析结果的影响，并建立了一套条件实验步骤。实验结果表明，当催化剂存在于样品中时，与不含催化剂时相比，煤液化油的失重在低于３００℃时增大，而在大于３００℃时减小；用Ｈ２作为载气时煤液化油的失重比用Ｎ２作为载气时大；催化剂的催化加氢性能与煤液化油的失重之间存在着定性的关联；催化加氢活性最高的催化剂表现出最大煤液化油失重。     

基于散射信号的超分辨光学相减显微镜

现有的光学超分辨显微成像技术主要依赖于特殊的荧光标记物,其对于大多数非荧光样品的超分辨成像就变得无能为力。因此我们提出将光学相减显微技术应用到非荧光样品的成像当中,利用普通共聚焦光斑和面包圈型光斑分别激发样品的散射光成像,从而得到样品同一区域的两幅图像,再通过图像相减的方法提高了图像空间分辨率。不同于一般的超分辨成像方法,这种光学相减显微镜不需要特殊的样品预处理过程,同时两次成像的激发光强度可以保持在一个较低水平,避免了样品损伤的影响。随后金纳米小球和有机聚合物微丝的散射成像实验证明了光学相减显微镜可以将空间分辨率提高到215 nm (0.33λ, 1λ = 650 nm),并且通过探测散射信号得到更多的样品细节信息。     

食物或食物原材料中特定属的植物的定量PCR检测方法

一种根据PCR技术测定食物或食物原材料中的特定属的植物量的方法，包括：（1）提供修正样品，其中来自作为检测靶的特定属的植物样品和标准植物样品的混合比率预先确定，并从该样品中提取基因组DNA；（2）通过向作为试验受试者的食物或食物原材料中添加已知量的标准植物样品来制成测试样品，并从该样品提取基因组DNA；（3）用引物和这些基因组DNA实施定量。     

电感耦合等离子体原子发射光谱(ICP-AES)法测定钢中硼时样品溶解损失及空白控制研究

用电感耦合等离子体原子发射光谱(ICP-AES)法研究了钢中硼的测定。实验发现,分析线在硼182.64nm处无硼铁基体空白值低于纯试剂(无铁)空白值。样品分析时,应进行无硼铁基空白实验,结果计算只能用此空白值。对普通玻璃烧杯和聚四氟乙烯烧杯的酸溶样品测定结果进行了比较,结果表明,测定结果和空白值相近且都很低,无硼普通玻璃烧杯也能满足钢中低含量硼的测定需要。通过对实验与报道结果比较分析表明,硝酸或王水加热溶解样品得到的溶液中硼没有损失,此溶液可测定钢中酸溶硼;用高氯酸发烟处理后,样品中酸不溶硼可能会溶解,但硼会挥发损失。因此,高氯酸发烟处理不能测定硼。     

Enhancement of digital gamma activation autoradiography capabilities by means of computer analysis of the time series images

It has been demonstrated that pixel-by pixel processing of series of autoradiography images for revealing the dynamics of decay of the induced radionuclides is an efficient approach for mapping of radionuclides in the sample in activation autoradiography. Concepts of virtual scanner and corresponding software for linearization of dependence of optical density on scanner response (luminosity) have been introduced. The concept provides unification of the subsequent processing of autoradiograms, irrespective of the method as to how the digital image has been obtained. Algorithms and the software for estimation of decay parameters of a radionuclide mixture for each pixel using a series of coaxially positioned images have been developed. The software is able generate a set of the derivative meta-images allowing a conclusion to be made about the presence of the inclusions in question. To increase the reliability of radionuclide mapping it is suggested to use analysis of distribution of half-life values estimated for pixels of image zone(s) pointed by a special mask.     

Combined optoacoustic/ultrasound system for tomographic absorption measurements: possibilities and limitations

In this paper, we present the OPUS (optoacoustic plus ultrasound) system, which is a combination of a wavelength-tunable pulsed optical parametrical oscillator (OPO) laser with a commercial ultrasound (US) scanner. Optoacoustic (OA) or, synonymously, photoacoustic (PA) imaging is a spectroscopic technique to measure optical absorption in semitransparent solids and liquids. The measured signal is an acoustical pressure wave, which represents the absorption of pulsed optical radiation. By temporally and spatially resolved detection of the pressure wave on the sample surface, a 2D or even 3D image of the distribution of the optical absorption in the sample can be generated. In recent years, OA tomography has found increasing application in medical imaging. Most of these applications are based on qualitative OA imaging. The reported system is intended primarily for breast cancer detection, in which the optoacoustic imaging modality offers additional information to the ultrasound image. Consequently, the system is developed in a way that the OA imaging mode can be installed without major changes to the US instrument. The capabilities of the OPUS system for the quantitative analysis of absorber concentrations in tissue models are exploited.     

乳清蛋白/阿拉伯胶复凝聚法制备载乙酸油酯微胶囊及其表征

油醇(十八烯醇)与乙酸酐的摩尔比为1/1.7,催化剂对甲苯磺酸用量为油醇与乙酸酐总质量的0.2%,25℃反应3h合成了昆虫性激素成分之一的乙酸油酯并对其进行了表征.以高分子电解质乳清蛋白(WP)和阿拉伯胶(GA)进行复凝聚制备聚合物微胶囊,对影响复凝聚的pH、两种电解质的配比及其浓度等因素进行了考察.结果表明在pH=3.5,WP/GA质量比1.5,WP和GA总浓度1.0%时复凝聚效果最佳.在该条件下以WP/GA为壁材对乙酸油酯进行了包覆,制备了不同壁材总浓度的载油微胶囊,对微胶囊的载油量和包覆率进行了测量.随着壁材总浓度的增大,芯材乙酸油酯包覆率呈现先上升后下降的变化趋势.用扫描电镜观察,发现制备的载乙酸油酯微胶囊大小在5～8μm并且乙酸油酯以核壳式结构的形式被包覆在微胶囊内部.     

Pressure induced change of order of cholesteric-smectic-A phase transition

The pressure dependence of the cholesteric-smectic-A phase transition of cholesteryl oleyl carbonate was determined by optical measurements up to 4.5 kbar and 95°C. The phase transition was indicated by the divergence of the wavelength of maximum light reflection. The corresponding phase diagram shows two straight lines which intersect at 1.43 kbar and 52.0°C thus pointing to a change in transition order. Taking into accounts the results of Keyes et al. a relatively strong correlation between change of positional and orientational long range order can be stated.     

Imaging and detection technologies for image analysis in electrophoresis

Image capture is the first step of image analysis. There are two major devices for image capture in the field of electrophoresis. One is the charged-couple device (CCD) camera and the other is the scanner. Image capture technologies have shown great progress in recent years especially in the field of fluorescence detection and chemiluminescent detection. The direction of image analysis is high resolution, wide dynamic range and high density precision and this holds true for the CCD camera system. Various components in the CCD camera system suitable for high-sensitive fluorescence detection and chemiluminescent detection are explained. As an example, the LAS-1000plus camera system which has 1364 x 922 pixels and generates 14-bits image is introduced. Powerful cooling enables overnight exposure of chemiluminescence. Introduction of blue light-emitting diode (LED) as excitation light source improved safety to eyes. Two types of scanners for fluorescence detection and the specific characteristics are explained. There are mechanical scanning systems using confocal optics and optical scanning systems using light collecting guide optics. Deep focusing range and equal fluorescence intensity at various depth is a characteristic feature of light collecting guide optics.     

Characteristics of the oxidation process in the oleyl alcohol-oleic acid,oleyl alcohol-methyl oleate,and oleic acid-methyl oleate systems by means of dielectric constant measurements

The investigation of the autoxidation process in the three model systems: oleyl alcohol-oleic acid, oleyl alcohol-methyl oleate, and oleic acid-methyl oleate by means of peroxide number and dielectric constant measurements were presented. The experiments were conducted at 60 °C, in the conditions of relatively lower amount of different kinds of hydrogen-bond polyassociates. One can state that in the case of the systems including oleyl alcohol it is possible to forecast the course of their autoxidation owing to the dielectric measurements.     

Optical activity in the isotropic and blue phases of two cholesterics

Optical activity measurements were performed in the isotropic phase and blue phases of two short-pitch cholesteric liquid crystals (cholesteryl oleate and cholesteryl oleyl carbonate). The data in the isotropic phase are interpreted in terms of five structural modes of the order parameter. Coupling between these modes gives rise to an extremum and a change of sign in the pretransitional optical rotation. The intensities of the polarized and depolarized component of the transmitted beam were measured as an extral tool to locate the phase transitions.     

Use of Computer-Assisted Color Treatment of Chromatograms in the TLC Determination of Tartrazine

A procedure was developed for the treatment of thin-layer chromatograms in the analysis of the Tartrazine E102 synthetic food dye. The procedure includes the conversion of a TLC plate into the Windows 95/98 bit-mapped graphics format using scanning on a flatbed scanner followed by the processing of the image obtained with the Adobe Photoshop 5.0 program package in the RGB color mode (red, green, and blue color channels).     

Optical activity in the isotropic and blue phases of two cholesterics

Optical activity measurements were performed in the isotropic phase and blue phases of two short-pitch cholesteric liquid crystals (cholesteryl oleate and cholesteryl oleyl carbonate). The data in the isotropic phase are interpreted in terms of five structural modes of the order parameter. Coupling between these modes gives rise to an extremum and a change of sign in the pretransitional optical rotation. The intensities of the polarized and depolarized component of the transmitted beam were measured as an extral tool to locate the phase transitions.     

Scanometric analysis of DNA microarrays using DNA intercalator-conjugated gold nanoparticles

We introduce a scanometric detection method for the analysis of DNA microarrays using DNA intercalator-conjugated gold nanoparticles that can be analyzed with the naked eye or with an optical scanner after the enhancement of the AuNPs. Moreover, we successfully detected a hemagglutinin-subtyping DNA array using this method.