高铜锌精矿处理的研究与实践

某厂一系统采用传统的湿法炼锌工艺。高铜锌精矿的处理量加大后，上清[Cu^2 ]达600mg／L左右，严重影响一段净化质量和一段净化后液的压滤速度，采用预除铜工艺。即可消除[Cu^2 ]过高的影响。     

A complete quantitative model of the isothermal vapor phase epitaxy of (Hg,Cd)Te

A quantitative model of isothermal vapor phase epitaxy is proposed. It can be applied to both closed and open tube systems. This model enables the prediction of compositional profiles of the layers grown by isothermal vapor phase epitaxy with dependence on the growth parameters and thermodynamical data of the (Hg,Cd)Te system. The dependence of compositional profiles of the ISOVPE layers on temperature and time of deposition, source to substrate spacing, mercury and inert gas pressures are discussed for both solid and liquid sources. Modification of the compositional profiles by the postgrowth annealing has also been studied. The proper choice of growth and annealing parameters makes the optimization of the profiles possible. The calculated profiles are compared with the experimental data and a satisfactory quantitative fit is found in most cases. The possible reasons for remaining discrepancies are discussed.     

超热中子活化分析的进一步研究

本文建议用一个一般化有利因子F=G~(1/2)R~(1/2)/R,来真实地反映超热中子活化导致的探测极限或计数统计的实际改善。经典的Brune定义和近来提出的Bem定义,可以分别看作本定义在G=R和G=1时的特例。为了得到最佳有利因子,推荐在不同孔道(甚至不同的堆)上分别进行全堆谱中子活化(TNA)和超热中子活化(ENA)。本文还全面评价了镉和氮化硼屏蔽体的利弊。此外,测定了38个反应,H_4孔道中ENA对于15～2孔道中TNA的有利因子。最后,对33个干扰反应,给出了在这两种照射条件下的干扰因子,并讨论了ENA的干扰放大。     

Growth conditions of the cubic phase cBN in boron nitride films

The nucleation and the subsequent coalescence period of the cubic phase cBN in sputter deposited BN-films is characterized by a shrinking of the film thickness. This is due to the transition of hBN into the denser cBN-phase which occurs inside a highly textured hBN base layer. The corresponding variation of the film thickness with the deposition time is described by a quantitative model. Full BN-stoichiometry in the hBN base layer is shown to be a mandatory condition for the nucleation process and the following growth of the cubic BN-phase. An increase of the substrate temperature fosters the incorporation of nitrogen into the growing film and, thus, the achievement of the stoichiometry condition.     

垂直布里奇曼法生长的Cd_（0.8）Mn_（0.2）Te单晶体中Te沉淀相分析

Cd1-xMnxTe（CdMnTe,CMT）是制备光学隔离器、太阳能电池、x射线和γ射线探测器的优选材料。本实验采用垂直布里奇曼（VB）法成功地生长出Cd0.8Mn0.2Te单晶体。用JEM-3010型高分辨透射电子显微镜（HRTEM）观察了CMT晶体中的纳米级Te沉淀。选区电子衍射得到了Te沉淀与CMT基体两相的合成电子衍射图。计算出单斜Te沉淀的晶胞参数为：a=0.31nm,b=0.79nm,c=0.47nm,β=92.71°。确定了Te沉淀和CMT基体的取向关系为（0 31）Te//（202）CMT,[100]Te//[111]CMT。最后,对Te沉淀（缺陷）的形成原因进行了分析。     

ICP-AES法测定食品用纸包装容器及材料中可迁移性重金属镉

用4%乙酸溶液,在60℃条件下浸泡食品用纸包装样品2h,用电感耦合等离子体发射光谱法准确测定浸泡中可迁移性重金属Cd的浓度,实验过程操作简便,精密度实验和回收率实验说明该方法检测结果准确可靠。     

电解金属锰中微量铅镉的极谱法连续测定

在氨基乙酸-氯化铵-盐酸羟胺底液中,Pb(Ⅱ)于-0.55 V(vs,SCE),Cd(Ⅱ)(vs,SCE)于-0.74 V产生一个灵敏的导数极谱波,铅的浓度在0.02~10μg/mL、镉的浓度在0.01~5μg/mL范围内与波高呈线性关系,大量的Mn2+使铅镉的波高下降,通过分离锰后可消除干扰。电解金属锰试样经硝酸分解后,利用高氯酸在加热至冒烟时的强氧化性,将锰离子氧化为MnO2予以分离后,可直接在上述条件下进行测定,铅标准回收率94.80%~102.20%,相对标准偏差0.43%~0.86%;镉标准回收率96.60%~101.80%,相对标准偏差2.37%~4.62%。     

黑藻对镉离子的生物吸附研究

研究了黑藻对镉离子的吸附作用,考察了溶液pH、镉离子初始浓度、吸附剂用量和吸附时间等因素对吸附的影响.在选定的吸附条件下,即pH为6.0,吸附剂用量为2 g·L-1,吸附时间为120 min时,对于50 mg·L-1的Cd+溶液,黑藻对Cd+的吸附效率为96%,吸附量为24.1 mg·g-1.常温下黑藻对Cd+的吸附作用可用Langmiur、Freundlich和Dubinin-Radushkevich(D-R)等温吸附模型进行拟合,相关系数r2分别达到0.9852、0.9901和0.9982,说明吸附反应符合这三种吸附模型.     

As Doping in (Hg,Cd)Te: An Alternative Point of View

Acceptor doping of many II–VI compound semiconductors has proved problematic and doping of epitaxial mercury cadmium telluride (MCT, Hg_1−x Cd _x Te) with arsenic is no exception. High-temperature (>400°C) anneals followed by a lower temperature mercury-rich vacancy-filling anneal are frequently required to activate the dopant. The model frequently used to explain p-type doping with arsenic invokes an amphoteric nature of group V atoms in the II–VI lattice. This requires that group VI substitution with arsenic only occurs under mercury-rich conditions either during growth or the subsequent annealing and involves site switching of the As. However, there are inconsistencies in the amphoteric model and unexplained experimental observations, including arsenic which is 100% active as grown by metalorganic vapor-phase epitaxy (MOVPE). A new model, based on hydrogen passivation of the arsenic, is therefore proposed.     

Finite elements modeling of multilayers of Cr/CrN

One of the most used methods for modeling different materials and their properties has been finite elements. In this work, mechanical properties of Cr/CrN multilayer coatings have been modeled by using finite elements, varying the period of layers (1, 5, 10 and 20 bilayers) and the thickness of the films between 0.5 and , in order to determine the behavior of the system. For this model, the software ANSYS was used to carry out simulation of the indentation process. For the analysis, a conical Berkovich indenter was built. The simulation consists in generating the stress-strain curves in the charge mode for obtaining Young's modulus of the total system, including the substrate, which is made by stainless steel 304. The curves showed a tendency of increasing of Young's modulus as a function of number of layers and thickness, which means an increasing in hardness.