组合抑制剂分离浮选细粒毒砂和硫化矿的研究(1)

本文选择了四种有机抑制剂A,B,C和YFA分别与Cu~(2 ),Zn~(2 )离子组成组合抑制剂,考查了它们对方铅矿、辉锑矿、黄铜矿和毒砂浮选行为的影响。结果表明,组合抑制剂对毒砂有独特抑剂效应,而对方铅矿、辉锑矿和黄铜矿略有不同程度的活化作用。在此基础上,选择了湖南省瑶岗仙钨矿精选工段含砷高达26%的硫化矿为对象,进行天然矿石的铜-砷分离试验,获得了极好的分离效果。     

混合精矿体系中方铅矿与黄铁矿浮选分离的矿浆电化学（Ⅱ）─—黄铁矿表面丁基双黄药的电化学还原动力学

双黄药是捕收剂黄药在硫化矿表面形成的典型疏水物质之一，本文采用恒电流极化法研究了黄铁矿表面丁基双黄药电化学还原的动力学行为，得到了动力学参数和动力学方程，表明其电化学还原的过电位较小（１５ｌｍＶ），还原反应轻易进行。     

硫化矿物浮选体系中外控电位电极与矿物颗粒间的电偶腐蚀作用及其浮选

硫化矿物浮选电化学研究中，控制电位的方式有两种：氧化还原药剂调控和外加电场电位调控。在外控电位浮选体系中，由于外控电位电极与硫化矿物的腐蚀电位差异，电极与硫化矿物碰撞接触时形成电偶腐蚀。从腐蚀电化学理论出发，研究了电极与硫化矿物形成的电偶腐蚀对硫化矿物浮选过程的影响，指出所形成的电偶腐蚀对硫化矿物浮选过程的影响与电极极性、电极材料、矿物的浮选特征等有关。当浮选过程需要发生硫化矿物颗粒表面的氧化时，工作电极应为阳极，电极材料应有较高的腐蚀电位；当浮选过程需要发生硫化矿物颗粒表面的还原反应时，工作电极应为阴极，电极材料应有较矿物颗粒低的腐蚀电位；要消除电极与矿物颗粒之间的电偶腐蚀作用，外控电位电极材料的腐蚀电位与目的矿物颗粒的腐蚀电位应相等或相近。研究结果可为实现硫化矿物浮选过程中外控电位方式、电极材料和电极极性的选择提供依据。     

磨矿环境对硫化矿物浮选的影响

论述了国内外关于磨矿环境对硫化矿物表面形态与性质、矿浆化学性质及其浮选行为的影响。在硫化矿物的磨矿－浮选体系中，磨矿过程是一个复杂的物理、化学和物理化学过程，存在着力学、电化学和机械力化学等多种作用因素，共同影响着硫化矿物的表面形态与性质、矿浆的溶液化学性质和硫化矿物的浮选行为。通过改变磨矿介质和在磨机中添加药剂等多种方式调控磨矿环境，可使硫化矿物的浮选分离得到改善。     

古尔胶和鞣酸添加方式对硫化矿浮选的影响

通过浮选实验研究了两种不同结构的有机抑制剂古尔胶和鞣酸以及这两种药剂与乙基黄药不同添加顺序对方铅矿、黄铜矿及黄铁矿浮选行为的影响.当先加入古尔胶时,古尔胶对三种硫化矿抑制作用较强;而古尔胶后于乙基黄药加入时,古尔胶对三种硫化矿的抑制作用明显减弱.鞣酸与乙基黄药不同的添加顺序不影响鞣酸对黄铁矿和方铅矿的抑制作用.紫外光谱研究表明,古尔胶对乙基黄药在三种硫化矿表面吸附没有影响,而鞣酸能够阻碍乙基黄药在硫化矿表面吸附.红外光谱研究表明,鞣酸通过化学作用吸附在方铅矿表面,因此能够抑制吸附了乙基黄药的硫化矿.     

有机电化学应用研究进展

本文简单阐述了有机电化学和电化学之间的关系,综述了有机电化学的主要应用研究领域及其发展情况,并对其未来发展趋势加以预测.     

多壁碳纳米管功能化的纳米片状硫化锡的制备和表征

本文提出一种新颖的多壁碳纳米管功能化的纳米片状硫化锡纳米复合物。该纳米复合物通过超声混合多壁碳纳米管和纳米片状硫化锡制备得到,并且用扫描和透射电化学显微镜对该复合物材料进行了表征。     

混炼插层法制备天然橡胶/蒙脱土纳米复合材料

采用有机改性蒙脱土和新型补强性促进剂，通过混炼插层法制备了天然橡胶／蒙脱土纳米复合材料，用X射线衍射和透射电镜表征了纳米复合材料的结构和形态，用表观交联密度测定和红外光谱研究了蒙脱土与橡胶的相互作用，同时用X射线衍射法研究了混炼和硫化过程中天然橡胶分子链对蒙脱土的插层过程．结果表明，蒙脱土在橡胶基体中以纳米级厚度片层分散；补强性促进剂能加强蒙脱土与橡胶间的结合；天然橡胶分子链在混炼过程中便开始对蒙脱土进行插层，并主要在焦烧时间前的硫化诱导期内完成大部分插层过程，硫化开始后蒙脱土的纳米级分散进一步完善，直至硫化完成．添加2％～10％有机蒙脱土的天然橡胶／蒙脱土纳米复合材料的力学性能和动态力学性能优于40％N770炭黑补强的硫化胶．     

有机电化学研究热点概述

近年来,有机电化学研究一直备受研究者关注,其研究成果被广泛应用于医药中间体、农药、染料、新型功能材料、新能源等众多领域中.从有机电化学在分析与合成两个方面,对目前有机电化学的研究现状和热点进行了概述.     

橡膠硫化促进剂双二甲氨硫羧(T.M.T.D.)的分析新方法

一、引言1839年人类开始知道将橡胶与硫黄一同加热来改变橡胶的性貭,但这样加热硫化需要时間較长,同时要用过量的硫黃,因此,对橡胶成品也产生了不良的影响,因此化学家們着手在硫化过程中加一些化学药品以縮短硫化时間和减少硫黄的用量。最初采用的化学药品只是一些无机化合物,如氧化鋅、石灰等。这些化合物被称为硫化促进剂。到了这个世紀初叶,又更进一步利用了有机化合物为硫化促进剂。有机硫化促进剂用量少,效力高,硫化时間短,硫化温度低,硫黄用量也少。同时制成品的各种性貭都比无机硫化促进剂好。因此近数十年,关于有机硫化促进剂的专利不下有数千种。其中最有效和在我国常用的約有十余种。     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。