The experimental study of the Bi–Sn, Bi–Zn and Bi–Sn–Zn systems

The binary Bi–Sn was studied by means of SEM (Scanning Electron Microscopy)/EDS (Energy-Dispersive solid state Spectrometry), DTA (Differential Thermal Analysis)/DSC (Differential Scanning Calorimetry) and RT-XRD (Room Temperature X-Ray Diffraction) in order to clarify discrepancies concerning the Bi reported solubility in (Sn). It was found that (Sn) dissolves approximately 10 wt% of Bi at the eutectic temperature.

The experimental effort for the Bi–Zn system was limited to the investigation of the discrepancies concerning the solubility limit of Zn in (Bi) and the solubility of Bi in (Zn). Results indicate that the solubility of both elements in the respective solid solution is approximately 0.3 wt% at 200 C.

Three different features were studied within the Bi–Sn–Zn system. Although there are enough data to establish the liquid miscibility gap occurring in the phase diagram of binary Bi–Zn, no data could be found for the ternary. Samples belonging to the isopleths with w(Bi) 10% and w(Sn) 5%, 13% and 19% were measured by DTA/DSC. The aim was to characterize the miscibility gap in the liquid phase. Samples belonging to the isopleths with w(Sn) 40%, 58%, 77/81% and w(Zn) 12% were also measured by DTA/DSC to complement the study of Bi–Sn–Zn. Solubilities in the solid terminal solutions were determined by SEM/EDS. Samples were also analyzed by RT-XRD and HT-XRD (High Temperature X-Ray Diffraction) confirming the DTA/DSC results for solid state phase equilibria.     

支持向量回归-吸光光度法同时测定溶液中的Pb,Cd,Zn

铅锌的湿法冶金实时监控需要同时快速测定溶液中的铅,镉,锌,因三者产生的吸收光谱严重重叠,故支持向量回归算法（support vector regression,简称SVR）作多变量标定,配合吸光光度法同时测定溶液中的Pb^2 ,Cd^2 ,Zn^2 ,并将计算结果与线性回归,人工神经网络的计算结果对比。结果表明SVR算法预报误差最小。这说明支持向量回归是一种多变量校正的有用算法。     

In formation: Support for flexibility, mobility, collaboration, and coherence

This paper describes support for flexibility, mobility and collaboration in engaging with, and making sense of, information. Our focus lies on the transitions people make between different, dynamic configurations of digital and physical materials, technologies, people and spaces. The technologies we describe have been developed in partnership with landscape architects over the past two years. We show that appliances and people can come together in a way that creates scope for such transitions, collaboration, and the emergence of new ways of working.     

碳,氢,氧,氮物系的焓值与燃烧温度

根据函数关系设计出一种表格,任何只含C,H,O,N 4种元素的可燃物质在标准大气压下与氧,空气或者任意比例的氧,氮混合物或化合物按化学计量比进行绝热燃烧时达到的温度都可精确地查得.本表还可用于非绝热燃烧过程的计算.     

Low temperature transient liquid phase bonding of Au/Sn and Cu/Sn electroplated material systems for MEMS wafer-level packaging

This paper presents the development of a low temperature transient liquid phase bonding process for 8″ wafer-level packaging of micro-electro-mechanical systems. Cu/Sn and Au/Sn material systems have been investigated under varying bonding temperatures from 240 to 280 °C and different dwell times from 8 to 30 min. The used bond frame had a width of 80 μm and lateral dimensions of 1.5 mm × 1.55 mm. The sealing frame of the cap wafer consisted of Au and Cu, respectively, and Sn. The MEMS wafer only holds the parent metal of Au or Cu. High quality bonds were confirmed by shear tests, cleavage analysis, polished cross-section analysis using optical and electron microscope, energy dispersive X-ray spectroscopy and pressure cocker test. The samples showed high shear strength (>80 MPa), nearly perfect bond regions and no main failure mode in the cleavage analyses. Non-corroded Cu test structures confirmed the hermeticity.     

Comparison between calculated and measured thermodynamic data of liquid (Ag, Au, Cu)-Sn-Zn alloys

The activity of zinc was measured in a series of liquid alloys in the three ternary systems, Ag-Sn-Zn [94Kar], Au-Sn-Zn [96Kar] and Cu-Sn-Zn [97Pen], with an emf (electromotive for e) method. From these measurements and the slope of the emf vs. temperature (dE/dT) all thermodynamic properties were derived. The experimental values were compared with calculated results. For these calculations four different models were applied and the thermodynamic data of the binary systems, obtained from the literature, were used.     

The activity coefficient of oxygen in ternary liquid An-Cu-Ag and similar alloys

A theoretical equation is derived for the activity coefficient of oxygen in ternary liquid solutions A-B-C. For this solution, the oxygen behavior in binary B-C may be described by the Wagner one- parameter equation, while those in binaries C-A and A-B by the two-parameter equation. The calculated values of the activity coefficient of oxygen in ternary Sn-Cu-Ag using this equation agree well with the experimental data reported in the literature.     

Quantitative simultaneous fit to the liquidus surface and thermodynamic data for the GaInSb system using an associated solution model for the liquid

The liquidus surface and extensive thermodynamic properties in the Ga-In-Sb system are fit simultaneously in a quantitatively satisfactory manner. The Ga_uIn_l-uSb solid solution phase is described as quasiregular in the components GaSb and InSb. The liquid phase is assumed to consist of the species, Ga, In, Sb, GaSb, and InSb which contribute to the excess Gibbs energy of mixing by quadratic and cubic terms in the species mole fractions. The simplest version of this model that leads to an asymmetric behavior of the component chemical potentials in the Ga-Sb and In-Sb systems is identified and found to be adequate. Contrary to common usage in the literature it is not assumed a priori that the relative (to its pure liquid elements) heat capacity of CaSb(s) (or InSb(?)) is equal to that of GaSb(?) (inSb(s)). This assumption is generally incorrect for associated solution models. Moreover, the parameters of the liquid phase are constrained so that the enthalpy and entropy of mixing of GaSb(?) at the melting point of GaSb(s) are properly related to the enthalpy and entropy of formation of GaSb(s). Two similar constraints are used for InSb(l).     

Gas sensitivity of Zn doped α-Fe2O3(SO4, Sn, Zn) to carbon monoxide

It is shown that the doping of Zn and Sn can improve the gas sensitivity of α-Fe₂O₃-based sensing material to CO. X-ray photo-electron spectroscopy analysis suggests that this is mainly due to the fact that the simultaneous doping of Zn and Sn can increase the S and hence SO₄²⁻ contents in the α-Fe₂O₃(SO₄²⁻, Sn, Zn) sensing material. The results also suggest that under a given condition, the gas sensitivity of α-Fe₂O₃(SO₄²⁻, Sn, Zn) to CO can be optimised by properly adjusting the doped Zn content.     

Simultaneous determination of Zn(II), Cd(II) and Hg(II) in water

The use of artificial neural networks (ANNs) as a tool for simultaneous determination of Zn(II), Cd(II) and Hg(II) in water has been investigated, by employing an optode based on the 2-(5-bromo-2-pyridylazo)-5-(diethylamino)phenol (Br-PADAP) complex immobilised on Amberlite XAD-4 resin.

Studies were performed with binary and ternary mixtures of Zn(II), Cd(II) and Hg(II) ions in the 0–3.0 mg l⁻¹ range (prepared in pH 8.0 NH₄Cl solution), in order to avoid sensing phase saturation. A 0.1 mol l⁻¹ HCl solution was employed to regenerate the optode after each measurement. Reflectance measurements were recorded in the 400–800 nm region after pumping metal ion solution for 1, 1.5, 2.0, 2.5 and 3.0 min. Spectra were smoothed by employing a weighted sliding average of three reflectance intensities (weights of 1:3:1) and normalised to the reflectance intensities of the immobilised reagent in the NH₄Cl solution. A feed-forward ANN with error back-propagation training algorithm was employed for data treatment. The ANN was initially fed through seven inputs neurons, corresponding to reflectance intensities at 558, 568, 583, 590, 605, 615 and 623 nm, and optimised with respect to the number of hidden neurons, momentum and learning rate. Binary mixtures of Zn(II) and Cd(II), and Hg(II) and Cd(II) were employed to evaluate the capability of prediction by the ANN. Measurements were carried out in triplicate leading to standard deviations (expressed in mg l⁻¹) better than 0.29 for Cd(II), 0.38 for Hg(II) and 0.35 for Zn(II) and absolute errors better than 0.14 for Cd(II), 0.31 for Hg(II) and 0.36 for Zn(II). Similar results were obtained when solution mixtures containing all three metal ions were employed in the studies.

These results indicate that ANN can be employed for simultaneous determination of metal ions in water. However, attention must be given to the leaching and to the saturation of the sensing phase, which limit the lifetime and analytical range of the sensor, respectively.     

径向基神经网络示波计时电位法同时测定铅和镉

将径向基神经网络用于Pb~(2 )和Cd~(2 )示波计时电位重叠切口的解析,建立了同时测定Pb~(2 )和Cd~(2 )的径向基神经网络示波计时电位分析新方法。实验表明:所建模型对训练集20个样本,预测结果相对标准偏差平均值仅为0．93%,而主成分回归模型预测结果为3．2%,偏最小二乘回归模型预测结果为3．0%。用本文方法预测的结果比主成分回归和偏最小二乘回归模型准确度高。     

Level-set method for the modelling of liquid bridge formation and break-up

In this paper, a level-set method is used to track the free surface and velocity profile of a Newtonian filament being stretched on an extensional rheometer. The method enables simulations to be performed from initial stretching until after the filament has broken up. The method used also follows the behaviour at the plate-liquid interface, allowing the air–liquid–solid contact point to move freely rather than being pinned at the edge of the plate. The simulations were validated by comparison with analogous experiments with glycerin, with excellent agreement between the two. The simulations were able to track the free surface throughout the experiment, including after the topological change associated with the filament breaking up. For the modelling of the fluid stretching, a novel grid deformation algorithm was introduced which allowed a tailored expansion of the domain, avoiding the need for specialised re-meshing.     

氟电极法测定Pb2+、Cd2+对植物细胞质膜透性的影响

以植物叶片为试验体系,测量它们在水溶液中不同浸泡时间的外渗液中 F~-离子浓度,并测量其相应的电导率,结果说明,植物细胞外渗 F~-离子浓度与总离子浓度成正比关系,因而 F~-离子选择性电极法可作为测量植物细胞质膜透性的一种方法,还试验了用 F~-离子选择性电极法测量 pb~(2+)、Cd~(2+)对植物细胞质膜透性的影响,实验结果表明,10~(-5)mol/L、10~(-4)mol/L 的 pb~(2+)、Cd~(2+)对 F~-离子选择性电极无干扰,而 pb~(2+)、Cd~(2+)在10~(-5)mol/L、10~(-4)mol/L 时就能使植物细胞质膜透性显著增大,表现出对植物细胞有一定的伤害作用,但不同植物对 Pb~(2)、Cd~(2+)重金属的抗性有些差别。     

Comparison of pair potential and thermochemical models of the heat of formation of BCC and FCC alloys

Data bases covering the thermochemical properties of solid solution phases are being assembled for a wide variety of applications. Such activities are often hampered by limitations on available experimental data and fundamental methods for estimating missing information. To bridge this gap the pair potential model has been developed and refined and is compared here with results drawn from thermochemical and phase diagram analysis of the heat of formation of bcc and fcc alloys. A computer program is presented providing a means for calculating the heat of formation for binary systems composed of twenty-seven elements. The results are compared with thermochemical values for sixty-six binary systems composed of all combinations of aluminum, cobalt, chromium, copper, iron, manganese, molybdenum, niobium, nickel, silicon, titanium and tungsten. The level of agreement provides a good measure of confidence in the usefulness of this pair potential model to obtain estimates for data which is otherwise available.     

Simultaneous measurement of Pb, Cd and Zn using differential pulse anodic stripping voltammetry at a bismuth/poly(p-aminobenzene sulfonic acid) film electrode

A novel sensor was developed for simultaneous detection of Pb, Cd and Zn, based on the differential pulse anodic stripping response at a bismuth/poly(p-aminobenzene sulfonic acid) (Bi/poly(p-ABSA)) film electrode. This electrode was generated in situ by depositing simultaneously bismuth and the metals by reduction at −1.40 V on the poly(p-ABSA) modified electrode. Compared with the bismuth film electrode, the Bi/poly(p-ABSA) film electrode can yield a larger stripping signal for Pb, Cd and Zn. Under the optimum conditions, a linear response was observed for Cd and Zn in the range from 1.00 to 110.00 μg L⁻¹ and for Pb in the range from 1.00 to 130.00 μg L⁻¹. The detection limits of Pb(II), Cd(II) and Zn(II) were 0.80, 0.63 and 0.62 μg L⁻¹, respectively. Finally this sensor had been applied to the simultaneous determination of Pb(II), Cd(II) and Zn(II) in river water samples and the results were quite corresponding to the value obtained by atomic absorption spectrometry.     

基于遗传算法的径向基神经网络及其在同时测定Fe Mn Cu Zn中应用

介绍了两种新的基于遗传算法的径向基神经网络(GA-Based RBFNN)训练算法.这两种算法均将遗传算法用于优化径向基神经网络的聚类中心和网络结构.第一种GA-Based RBFNN算法对所有训练样本采取二进制编码构成个体,优化径向基函数中心的选取和网络结构;第二种GA-Based RBFNN算法中,RBFNN采用自增长算法训练网络隐含层中心、采用十进制对距离因子ε编码构成染色体,优化网络.将两种GA-Based RBFNN算法应用于Fe、Mn、Cu、Zn同时测定的光谱解析,计算结果表明,本文的GA-Based RBFNN算法较通常的遗传算法与径向基人工神经网络(GA-RBFNN)联用,即在GA选择变量的基础上,再用RBFNN作数据解析的GA-RBFNN方法,在增强网络的泛化能力、提高预测的准确性等方面具有明显的优势.从这两种GA-Based RBFNN的比较看,第二种算法在性能上优于第一种算法.     

Windows工作环境下Oracle、VC＋＋和Matlab的联合应用

在分析了Oracle、VC 和Matlab各自特点的基础上,提出了一种基于三者的编程方法。在该方法中,用VC＋＋实现复杂友好的操作图形界面,用Oracle管理基本数据,用Matlab在后台完成复杂的计算。