ICP-AES测定载金树脂物料中的金

试样经高温灰化后,用王水溶解残渣后定容,采用ICP-AES测定“载金树脂物料”中的金含量.实验结果表明测定相对标准偏差小于3％,回收率在97.1 ％-107％之间,方法简便,快速,可靠.     

红景天中微量元素的测定方法研究

采用高压硝化罐法对试样进行消解,分别用ICP-AES和AAS两种方法测定了红景天中Mg、Fe、Zn、Mn等微量元素的含量,回收率在96.0%—102.0%之间,相对标准偏差均小于2.00%。对两种方法比较无明显差异,但ICP-AES法简单,快速,灵敏度高,准确性好,且多元素同时测定。它能为红景天的药理、药效研究和综合开发利用,提供了广泛的科学依据。     

ICP-AES测定铜精矿中的铜含量

试样经湿法消解后,采用ICP-AES测定铜精矿中的铜含量。按本方法所测铜精矿标准物质(YT9104),其测定结果的相对标准偏差RSD为0.329%。     

ICP-AES测定铜镏中多种常微量元素的含量

试样经微波消解后,采用ICP-AES测定铜镏中多种常微量元素含量。实验结果表明,测定相对标准偏差均小于4.0%。回收率在96.5%—107.0%之间,方法简便,快速.可靠。     

ICP-OES测定铜尾矿中锡的含量

采用电感耦合等离子体-发射光谱法(ICP-OES)测定了铜尾矿中锡的含量.该方法检出限为0.006%,加标回收率为98.3%-102.8%.对国标样品的测定结果令人满意.方法简单快捷,对矿物中锡含量的测定具有参考意义.     

黑米中微量元素含量的测定

采用高压密封消解罐法对样品进行处理,以电感耦合等离子体-原子发射光谱法(ICP-AES)和原子吸收光谱法(AAS)测定黑米中Mn、Cu、Fe、Mg等微量元素的含量,lCP-AES更佳.回收率为92.2%-109%,相对标准偏差小于2.67%.实验证明,黑米含有丰富的对人体有益微量元素,是一种健康食品.     

FAAS测定进口铜锍中的铜、铁、铅、锌、镉和锰

铜锍及含铜烧结物料经混合酸溶解后,在10％ HCl介质中,采用火焰原子吸收光谱法测定其铜、铁、铅、锌、镉、锰元素的含量.讨论了溶样条件、基体效应和共存元素干扰等影响因素,采用基体匹配校正了基体成分的光谱干扰.在选定的仪器最佳条件下对样品进行测试,共存元素之间没用明显的干扰,方法的检出限低,且简便快速、结果可靠,适用于大批量铜锍进出口检验.     

ICP-AES测定高含量锌、镉和铜

采用ICP-AES测定高含量锌、镉和铜,选择了最佳仪器工作条件和样品处理方法。在实验优选条件下,对铜镉渣中铜的含量为8%—12%;镉的含量为35%—38%;锌的含量为21%—23%进行了测定。回收率分别为铜99.8%—100.0%,镉98.3%—99.9%,锌99.3%—99.5%。     

ICP-AES测定金红石中的二氧化锆、三氧化二铁、二氧化硅含量

叙述了ICP-AES测定金红石中二氧化锆、三氧化二铁、二氧化硅含量的方法。将样品用过氧化钠-氢氧化钠混合熔剂熔融,采用基体匹配扣除基体干扰,被测杂质元素不用分离,直接测定。     

测定甘蔗中铅、铜、镉方法的研究

甘蔗（Sugar cane）是禾本科植物,产于热带、亚热带地区,是生产白砂糖、赤砂糖、红糖等食糖的主要原料,由于生长地气候、土壤、地质条件、环境的不同,甘蔗中的有害物质、有害元素的含量也不同。本研究采用电感耦合等离子体-原子发射光谱仪（ICP-AES）同时测定甘蔗中的3个有害元素铅、铜、镉。方法简便,检测速度快,结果准确,适用于甘蔗检验。     

电感耦合等离子体质谱法测定铜矿区20种植物中的金银

采用灰化-王水处理试样,选取103 Rh和203 Tl作为测定107 Ag、109 Ag和197 Au的内标元素,建立了电感耦合等离子体质谱法测定铜矿区栓皮栎等20种植物中金和银的方法。所建立方法用于不同矿区植物样品的分析,相对标准偏差(n=5)为9.05%～0.85%,加标回收率在93.6%～101.6%之间,Au和Ag检出限分别为0.048和1.06ng.g-1。该方法简便、准确,适用于铜矿区植物中金和银的测定。测定结果表明,矿区中金和银含量因不同植物而存在较大差异,变动范围为Au:0.18～0.99ng.g-1,Ag:282～2 150ng.g-1,其中凤尾蕨、芒萁和长叶实蕨中Ag具备地球化学异常特征,可作为找矿有效指示的植物。     

Solid solutions of hydrogen in gold,silver and copper

The temperature variation of the hydrogen solubility of copper, silver, and gold in equilibrium with H₂-gas at atmospheric pressure has been measured. Values for the relative partial enthalpy and partial excess entropy of the interstitially dissolved hydrogen atoms have been estimated from the solubility data.The experimental data are compared with those of previous investigations. The partial entropy values obtained for, copper and silver show a ‘regular’ behavior when compared with partial entropies for other cubic metals having a small occludive capacity for hydrogen. The gold-hydrogen system is, however, anomalous and has a partial excess entropy which is essentially zero.     

Manufacturing and modelling of sintered micro-porous absorption material for low frequency applications

A novel sintering based method to produce thin ultrahigh molecular weight polyethylene, UHMWPE, absorption material layer to increase absorption at low frequencies is introduced. The experimental impedance tube measurement results show that a 4 mm thick sintered sample layer increases absorption at a low frequency range below 1000 Hz compared with commercial melamine and polyester absorption foam samples. To cover a wider frequency range, multilayer structures composed of a sintered micro-porous material layer and commercial melamine and polyester foam layers are created and examined. The sintered sample layer also increases absorption in multilayer structures at low frequencies. Absorption coefficient values above 0.5 are reached starting from 200 Hz with multilayer structures. Software exploiting Biot’s theory of porous materials has been adopted to fit the experimental absorption data for sintered samples, commercial foams and multilayers. Software based on Biot’s theory was found to deliver quite good correlation with measured absorption coefficient values, with disagreements below 10% between the measured and estimated values.     

Enhanced thermoelectric performance of spark plasma sintered copper-deficient nanostructured copper selenide

We report the thermoelectric properties of nanostructured Cu-deficient Cu₂Se, which was synthesized by high energy ball milling followed by spark plasma sintering. Our method obtained a significant enhancement in the thermoelectric figure of merit (ZT), i.e., ~1.4 at 973 K, which was ~30% higher than its bulk counterpart. This enhancement in the thermoelectric performance was due mainly to a significant reduction in the lattice thermal conductivity, which was attributed to enhanced phonon scattering at various length scales by nanoscale defects as well as abundant nanograin boundaries. The nanoscale defects were characterized by transmission electron microscopy of the nanostructured Cu_2−xSe samples, which formed the basis of the ZT enhancement.     

Mechanical characterization of sintered piezo-electric ceramic material using scanning acoustic microscope

Lead Zirconate Titanate (PZT) is a piezo-electric ceramic material that needs to be characterized for its potential use in microelectronics. Energy dispersive X-ray analysis (EDX) is conducted to determine the chemical composition of the PZT ceramics. The scanning electron microscope (SEM) is performed to study the surface morphology, grain structure and grain boundaries. The SEM image helps us to understand the surface wave propagation and scattering phenomena by the PZT and the reason for its anisotropy and inhomogeneity due to the grain structure. In this paper scanning acoustic microscopy at 100 MHz excitation frequency is conducted for determining mechanical properties of PZT. Earlier works reported only the longitudinal wave speed in PZT while in this paper longitudinal, shear and surface acoustic wave speeds of sintered PZT are measured from its acoustic material signature (AMS) curves, also known as V(z) curves. AMS or V(z) curve is the variation of the output voltage as a function of the distance between the acoustic lens focal point and the reflecting surface. The average velocities of longitudinal, shear and surface acoustic waves in a PZT specimen are determined from its V(z) curve generated at 100 MHz excitation frequency and found to be over 5000 m/s, over 3000 m/s and between 2500 and 3000 m/s, respectively. From these velocities all elastic constants of the specimen are obtained.     

Narrowband luminescence of copper in the presence of gold nanoparticles

Narrow bands were experimentally revealed in the spectrum of copper under a layer of gold nanoparticles. Luminescence was excited with a He–Ne laser (6328 Å). The spectra of films of individual metals contained no similar bands. Experimental conditions and recorded spectra were presented, and some possible explanations of the observed effect were discussed.     

Photopatterning of gold and copper surfaces by using self-assembled monolayers

A photolithographic technique was successfully employed to generate micropatterns of gold and copper by using self-assembled monolayer (SAMs) as resist materials. Copper patterns were successfully prepared from SAMs of 11-mercaptoundecanoic acid (MUA) and dodecanethiol (DDT) on Cu after UV irradiation followed by etching but gold patterns were prepared only from the SAM of MUA and not from the SAM of DDT, which revealed the difference of photooxidation of the metal–sulfur bond on SAMs. However, the maximum resolution of the pattern was about 1.0 μm on gold and 5.0 μm on copper. This may be due to lower quality packing of SAM on copper than gold. Ellipsometric and cyclovoltammetric observation of SAMs during the UV irradiation indicated the gradual removal of SAMs on copper and gold. Photopatterning of gold and copper by using SAM is more compatible with the current microelectronics process and is complementary to the microcontact printing technique.     

Structure and energetics of nickel, copper, and gold clusters

The most stable structures of Cu_N, Ni_N, and Au_N clusters with 2≤N≤60 have been determined using a combination of the embedded-atom (EAM), the quasi-Newton, and our own Aufbau/Abbau methods for the calculation of the total energy for a given structure, the structures of the local total-energy minima, and the structure of the global total-energy minimum, respectively. We have employed two well-known versions of the EAM: (1) the ‘bulk’ version of Daw, Baskes, and Foiles and (2) the Voter-Chen version which takes into account also properties of the dimer in the parameterization. The lower-energy structures (also for the smallest) of Cu_N and Ni_N clusters (i.e., structural details as well as symmetry) obtained with the two versions are very similar. Thus, our study supports an universality of the bulk embedding functions for copper and nickel. But for gold clusters the differences between structures calculated with the two different versions of the EAM are significant, even for larger clusters.     

Determination of gold and silver in dross using EDXRF technique

Gold and silver in dross were determined by energy‐dispersive X‐ray fluorescence technique. Sample was prepared by pressed pellet method using microcrystalline cellulose powder as binder, and a method of standard additions was used for quantification. L_β X‐ray of gold (11.4 keV) and K_β X‐ray of silver (24.9 keV) were used for analysis. The measured concentrations of gold and silver were 132 ± 8 and 1181 ± 84 mg kg^?1, respectively. The results were validated by instrumental neutron activation analysis technique. The t‐test indicated that there was no significant difference between results obtained by the two techniques. Energy‐dispersive X‐ray fluorescence is a simple, precise and accurate technique for the determination of gold and silver in dross. Copyright © 2014 John Wiley & Sons, Ltd.