新版X射线残余应力测定国标中的新技术与新要求

简要介绍了现行的X射线残余应力测定的国内外标准及国标(GB/T 7704)的历次制修订情况,并对新版X射线残余应力测定国标的修订背景、依据以及内容结构作了说明,重点对新版国标中的新技术、新方法和新要求等进行了解析,以期给我国残余应力测试工作者、测试设备制造者以及实验室管理者提供必要的技术和方法支持。最后就新版国标中存在的一些问题进行了分析讨论。     

地表水总磷测定法优化及其有关问题的探讨

本文根据国标法过硫酸钾消解钼酸铵分光光度法（GB／T11893～1989）存在的一些普遍问题,结合在工作中总结出的方法借用COD消解思路优化、建立快速测定地表水水质总磷国标分析方法,通过对本法从测定条件、准确度、精密度等方面多次实验,并与标准方法进行比较分析结果,同时对优化国标方法测总磷应注意有关问题进行了探讨。     

食品中磷的测定方法的改进

用定磷试剂代替国标方法中的钼酸铵、对苯二酚和亚硫酸钠溶液与待测液反应生成磷钼蓝进行比色分析测定磷含量,避免了有毒试剂对苯二酚对试验人员的危害及对环境的污染。试验结果表明,改进法提高了测定灵敏度,扩大了被测液的酸度范围,方法的检出限为1.3μg,回收率为96.8%～99.4%,测定结果与国标方法的测定结果比较无显著统计学差别,该方法可用于食品中磷的测定。     

奶茶制品中茶多酚含量的测定方法改进

针对国标中奶茶制品中茶多酚含量的测定中遇到的问题,对国标及其他传统沉淀剂对市售奶茶制品的沉淀效果进行比较分析,最终选用乙酸作为沉淀剂进行方法改进,并分析在测定过程中乙酸的最佳用量。该处理方法沉淀效果好,实验操作简单、快速,毒性低,适用于奶茶制品中茶多酚含量的测定。     

饲料中镉的测定

本文介绍了利用测定配合饲料粗灰分、钙、总磷的同一处理样进行镉的测定,本方法检测结果与现行国标方法相一致。     

浅谈面制食品中铝的测定方法

本文对国标方法测定面制食品中铝含量方法进行了分析,探讨干消化-铬天青s分光光度法测定面制食品中铝的含量,并对结果和结论进行了总结。     

离子色谱法测定蟹肉中的亚硫酸盐

建立了离子色谱法测定蟹肉中亚硫酸盐（二氧化硫）的检测方法,回收率在73.1%～92.6%和精密度<6.7%,探讨了样品前处理方法及色谱条件;通过比较离子色谱法与国标法,结果表明,两方法之间没有显著性差异,离子色谱法克服了国标法中汞的污染和色素干扰问题。     

用直接测汞法快速测定干紫菜中总汞含量

建立了直接测汞法快速测定干紫菜中总汞的方法。样品进行热分解,样品中的汞经金汞齐化管富集,加热破坏汞齐后,采用冷原子吸收光谱进行总汞分析。试验结果表明,采用直接测汞法测定干紫菜中总汞含量有良好的效果,完全可以替代国标方法GB／T5009．17-2003。该方法快速、准确且无药品试剂污染,重现性优于采用国标方法测定的结果。     

梅特勒-托利多参与热分析比热容国标制订会议

在今年3月25-27日由全国塑料标准化技术委员会石化塑料分标委组织的“塑料差示扫描量热法（DSC）比热容测定国标制订第一次会议”上，梅特勒-托利多作为合作方，举行了为期1天的热分析技术专题讲座，以配合国标制订工作。     

微量元素预混合饲料混合均匀度测定法

本文用原子吸收分光光度法通过测定微量元素预混合饲料中铜，铁，锌含量计算出变异系数，由铜，铁含量计算得到的变异系怀国标法相近，本法较国标法简捷，快速。     

Desorption process of copper chlorides from copper surface

Gaseous copper chlorides can be employed as precursors in a newly developed Cu-CVD method called metal chloride reduction-chemical vapor deposition (MCR-CVD). More than one species exists in the gas phase of copper chloride. We studied the gas phase composition of copper chlorides generated by etching of copper surface by electron impact-mass spectrometry. The composition of gaseous species can change because of gas phase reactions. After desorbing from the copper surface, copper chloride reached equilibrium composition immediately.     

Bacterial synthesis of copper/copper oxide nanoparticles

A bacterial mediated synthesis of copper/copper oxide nanoparticle composite is reported. A Gram-negative bacterium belonging to the genus Serratia was isolated from the midgut of Stibara sp., an insect of the Cerambycidae family of beetles found in the Northwestern Ghats of India. This is a unique bacterium that is quite specific for the synthesis of copper oxide nanoparticles as several other strains isolated from the same insect and common Indian mosquitoes did not result in nanoparticle formation. By following the reaction systematically, we could delineate that the nanoparticle formation occurs intracellularly. However, the process results in the killing of bacterial cells. Subsequently the nanoparticles leak out as the cell wall disintegrates. The nanoparticles formed are thoroughly characterized by UV-Vis, TEM, XRD, XPS and FTIR studies.     

Influence of copper nanoparticles on copper requiring enzyme

This study describes the influence of copper nanoparticles (CNPs) on activity and kinetic properties of a Cu²⁺ requiring sorghum oxalate oxidase (OxO). CNPs were synthesised by citrate-induced reduction of CuCl₂ and their size (range 13–58?nm) was determined by transmission electron microscopy. The CNPs were characterised by scanning electron microscopy and X-ray diffraction studies. These CNPs enhanced OxO activity by 30%. Thermal and storage stability were increased, while Km value for oxalate decreased in the presence of CNPs. CNPs protected OxO against chelation by diethyldithiocarbamate, a Cu²⁺ specific chelator. The analytic use of OxO in the presence of CNP for determination of oxalate in food stuff is demonstrated.     

Nanostructured copper and copper oxide thin films fabricated by hydrothermal treatment of copper hydroxide nitrate

Metallic copper and copper oxide thin films were fabricated on surface of glass slide substrates. Copper oxide thin films were prepared by a hydrothermal method using an α-phase layered hydroxide, copper hydroxide nitrate as a precursor. Morphology, thickness and crystallite size of the obtained copper oxide thin films changed by changing the time of hydrothermal treatment. Accordingly, the copper oxide thin films showed various water contact angles and optical band gaps. As, the optical band gap of the nanostructured copper oxide thin films increased with an increase in hydrothermal time from 1.85 to 2.95 eV. Moreover, the water contact angles changed from 16.4 to 38.8° by changing the hydrothermal time. By a reductive hydrothermal-treatment route, the copper oxide thin film was reduced to metallic copper thin film without any particle growth.     

Field emission from copper phthalocyanine and copper hexadecafluorophthalocyanine nanowires

Copper phthalocyanine (CuPc) and copper hexadecafluorophthalocyanine (F₁₆CuPc) nanowires were fabricated by vapor deposition. The nanowires were studied by scanning electron microscopy and transmission electron microscopy. Field emission properties of these nanowires were studied. The field emission properties were strongly dependent on the substrate temperature and the material used, and the best results are obtained for β-phase CuPc nanoribbons. Different dependences of field emission properties on the substrate temperature were obtained for the two materials investigated. The obtained results are discussed.     

The wetting of carbon by copper and copper alloys

The effects of alloying additions on the wetting of two types of carbon, HX30 graphite and vitreous carbon, have been investigated, with a view to developing a system for metal impregnation of carbon fibre assemblies. Pure copper is inert and non-wetting but two additions caused the copper to wet: Cr on both substrates and V on the vitreous carbon only. Many of the additions formed a carbide reaction layer at the interface, and in the two wetting systems this was a thin, continuous, coherent layer. The data have been analysed in terms of the chemical and physical properties of the system and it was found that the wetting behaviour of copper alloys on HX30 graphite and vitreous carbon could be explained in terms of the behaviour of the reaction product carbides of the alloying addition when these existed.     

The chemical vapor deposition of copper and copper alloys

The chemical vapor deposition of copper and copper alloys for very large scale integrated interconnects is described using a series of Lewis base stabilized copper (I) 1,1,1,5,5,5-hexafluoro-2,4-pentanedionato (hfac) complexes. When the Lewis base is dimethyl-1,5-cyclooctadiene, high-purity copper metal is deposited at substrate temperatures from 150 to 250 °C. The deposition rate becomes mass-transport limited at the higher substrate temperatures, but excellent filling of sub-micron vias (3:1 aspect ratio) was achieved. The deposition of copper-tin alloys can also be achieved when vinyl trialkyltin is used as the Lewis base. At 180 °C, a carbon-free copper film, containing 0.6 at.%Sn, is deposited. A very strong substrate temperature dependence towards film purity was observed and results from thermal decomposition of the tin-containing ligand. These preliminary results demonstrate the utility of using single-source, mixed-metal precursors for copper alloy formation.     

Preparation of superconducting-grade copper from commercial grade copper salt

Fine samples with nominal composition of Bi_1·6Pb_0·4Sr₂Ca₂Cu₃O _x have been produced by solid state method using various purity grades of starting copper oxide powder. Studies onT _c and high-T _c volume fraction measurements of these samples revealed that the samples produced using CuO powders obtained in laboratory after double purification of the commercially available copper salts have higherT _c (104·46 K) and increased percentage of highT _c volume fraction (58%) compared to even the samples prepared from Aldrich grade (99·99%) CuO. A simple and cost-effective chemical route for the purification of CuO from commercially available copper salts has been outlined.     

Production of ultrahigh purity copper using waste copper nitrate solution

The production of ultrahigh purity copper (99.9999%) by electrolysis in the presence of a cementation barrier has been attempted employing a waste nitric copper etching solution as the electrolyte. The amount of copper deposited on the cathode increased almost linearly with electrolysis time and the purity of copper was observed to increase as the electrolyte concentration was increased. At some point, however, as the electrolyte concentration increased, the purity of copper decreased slightly. As the total surface area of cementation barrier increased, the purity of product increased. The electrolyte temperature should be maintained below 35 degrees C in the range of investigated electrolysis conditions to obtain the ultrahigh purity copper. Considering that several industrial waste solutions contain valuable metallic components the result of present study may support a claim that electrowinning is a very desirable process for their treatment and recovery.