Thermodynamics and surface properties of liquid Bi–In alloys

The mixing behaviour of liquid Bi–In alloys has been described in terms of energetics and structure through the study of their thermodynamic, surface and structural properties by using the Complex Formation Model (CFM) in the weak interaction approximation and by postulating BiIn-chemical complexes as energetically favoured. The new Bi, In and Bi–In surface tension experimental data set, obtained by the large drop method in the temperature range 553–873 K, has been analysed in the framework of the CFM and compared with the calculated values as well as with corresponding literature data. The structural characteristics of Bi–In melts are described by the two microscopic functions, i.e. the concentration fluctuations in the long-wavelength limit and the Warren–Cowley short-range order parameter.     

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。     

Cd、Pb、Cu、Zn、As复合污染对龙须草生长的影响

本文研究了不同处理水平下Cd、Pb、Cu、Zn、As复合污染对龙须草生长的影响。结果表明,龙须草地下部对重金属的抗性大于地上部。在接近土壤环境质量二级标准上限值时,龙须草生长正常,减产幅度<10%;在含Cd5mgkg-1、Pb600mgkg-1、Cu125mgkg-1、Zn300mgkg-1、As50mgkg-1的复合污染土壤上,龙须草地下部干重与对照相比较差异性不显著(α=0.01);在含矿毒水河水污染土壤和尾矿砂污染水稻土壤上,龙须草地下部干重与对照相当,且地上部干重分别为对照的61.58%和40.64%。这些说明龙须草在土壤重金属复合污染修复中具有良好的应用前景。     

低分子有机酸对土壤中重金属的解吸及影响因素

研究了柠檬酸、草酸、酒石酸和苹果酸对矿区土壤中重金属Pb、Cd、Cu和Zn的解吸行为,并探讨了介质pH值对其解吸土中重金属的影响。振荡解吸试验结果表明四种低分子有机酸对供试污染土壤中Pb、Cd、Cu和Zn都具有一定的解吸能力。由于土壤中重金属有效态含量较低,各重金属的解吸率都不高。在对Pb和Cd的解吸中,各低分子有机酸能力大小顺序为柠檬酸>酒石酸≈苹果酸>草酸;Cu的解吸顺序为柠檬酸>草酸>酒石酸≈苹果酸;Zn的解吸顺序为酒石酸>柠檬酸≈苹果酸>草酸。低分子有机酸随浓度的增加,其解吸能力提高。低分子有机酸对重金属的解吸量随pH值的降低而增加。     

Calorimetric study and thermodynamic description of Ga-Ge-Li liquid alloys

This publication contains the thermodynamic results received by the drop calorimetry method. The experiments were conducted for four different cross sections, at the temperature of 1080 K. The investigated alloys were as follows: (Ga_0.75Li_0.25)_1-xGe_x, (Ge_0.50Li_0.50)_1-xGa_x, (Ga_0.50Li_0.50)_1-xGe_x, (Ga_0.25Li_0.75)_1-xGe_x. The mixing enthalpy changes measured for all four cross sections of the Ga-Ge-Li system are characterized by negative deviations from the ideal solutions. The Muggianu model with the ternary interaction parameters was applied to elaborate the experimental data of the mixing enthalpy change with the use of the optimized thermodynamic parameters of the binary systems available in the literature.     

重金属单一污染对龙须草叶绿素含量和抗氧化酶系统的影响

盆栽试验的结果表明:Cd、Pb、Cu、Zn和As单一污染处理时龙须草叶绿素含量随着重金属处理浓度的增加呈现先升后降的趋势,但其总叶绿素含量和叶绿素a/b比值均低于对照;龙须草SOD的活性随着Zn、As单一污染处理浓度增加呈现先升后降的趋势,而随着其它三种重金属处理浓度的增加呈现下降趋势;龙须草CAT和POD的活性随着As处理浓度的增加呈现出上升趋势,而随着其它四种重金属处理浓度的增加呈现先升后降趋势。     

单一重金属胁迫对灯心草生长及生理生化指标的影响

通过盆栽试验研究了不同浓度处理水平的Cu、Cd、Pb、Zn、As五种重金属单一胁迫对灯心草生长及其生理生化特性的的影响。结果表明:种植灯心草土壤中的Cd、Pb、Cu三种重金属临界值可分别设定为10mg kg-1、100 mg kg-1、100mg kg-1。灯心草不适合在Zn污染的土壤中种植,土壤中As临界值尚需作进一步的研究来确定。各单一重金属胁迫对灯心草叶绿素的合成均有很大程度的抑制作用,剂量-效应关系明显。灯心草三种保护酶对于不同浓度处理水平重金属胁迫的响应不同:在土壤环境质量低浓度设置范围内三种酶有较好的协同效应能共同抵御重金属胁迫造成的膜伤害,表现出较强的自我调节能力。而在高浓度处理水平时,三种酶活性呈现不同的变化趋势。灯心草生理生化指标对重金属胁迫的响应存在元素种类之间的差异。各单一重金属对灯心草生长抑制及生理毒害效应大小排序为:Zn>As>Cu>Pb>Cd。     

Cd、Pb、Cu、Zn、As复合污染对杂交水稻苗的联合生理毒性效应及临界值

通过室内土培试验,研究了不同浓度的Cd、Pb、Cu、Zn、As等5种重金属复合污染对水稻苗的联合生理毒性效应,并对其临界值进行了探讨。结果表明:5种重金属污染对水稻苗的联合生理毒性效应随其污染浓度的增加而显著增强,剂量—效应关系明显。除处理(1)外,其余各处理对水稻苗体的诸项生长指标的抑制均达到了极显著的程度(P<0.01),且对根长的抑制明显大于苗长。随着复合重金属污染浓度的增大,水稻苗叶片中叶绿素含量急剧减少;丙二醛(MDA)含量迅速增加;POD和SOD酶活性呈先升后降的变化趋势。铅锌尾矿和矿毒水污染对水稻苗生长和各项生理生化指标的影响也均达到了极显著程度,但在二者污染下,POD和SOD酶活性均高于对照,铅锌尾矿的毒性效应大于矿毒水。以酶活性为参考指标,可以将土壤环境质量二级标准上限值设定为土壤中Cd、Pb、Cu、Zn、As等5种重金属对该水稻品种的临界毒性效应值。     

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.     

Cd2+掺杂SnO2纳米棒的制备与特性研究

在微乳液中SnCl和CdCl的混合水溶液与KBH4水溶液的还原反应制备了Cd2 掺杂SnO2纳米棒前驱物.在NaCl KCl熔盐介质中,660℃焙烧前驱成功制备了Cd2 掺杂SnO2纳米棒一维纳米材料.利用TEM、XRD、XPS和H2-TPR对SnO2纳米棒形貌、成分和材料表面氧吸附特性、H2还原特性进行了表征和分析.SnO2纳米棒直径为10nm～20 nm,长度从几百个纳米到几个微米,Cd2 掺杂后的SnO2纳米棒材料中CdO的含量可达5%.TPR的结果表明,Cd2 掺杂SnO2纳米棒表面吸附大量的氧具有较好的氧化还原特性.以SnO2纳米棒为原料,制备了厚膜气敏元件,考察了其H2敏感特性.     

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.     

Study of the solubility of Pb,Bi and Sn in aluminum by mixed CALPHAD/DFT methods: Applicability to aluminum machining alloys

The aim of this work is a formulation of a thermodynamic model for the development of new aluminum machining alloys. The three additives Bi, Pb and Sn have proven to help machining. Hence, a review of the literature showed that the liquid phase equilibria and thermodynamic data for the three binary systems Al-Bi, Al-Pb and Al-Sn is very thorough but the limited information for the FCC solution required the use of Density Functional Theory (DFT) to predict thermodynamic data. The partial heat of mixing of these three machining additives in Al(FCC) are obtained and the results helped to improve the thermodynamic model using the CALPHAD method. It was shown that for all three binary systems, the thermodynamic data obtained at three fixed compositions and that obtained for a very dilute solution gave different enthalpy curves. The thermodynamic model was used to compute the ternary systems Al-Bi-Pb, Al-Bi-Sn and Al-Pb-Sn and small adjustable parameters were added to reproduce the literature data.     

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).