Effect of surfactants on preparation of nanometer TiO2 by pyrohydrolysis

The nanometer TiO2 was prepared by pyrohydrolysis with titanic solution.The effects of species and content of the surfactants on the particle size,morphology and phase of TiO2 were studied by using LPA,XRD and TEM respectively.The results show that it is beneficial to reducing the aggregation of TiO2 particles with adding surfactants to the solution.Nanometer TiO2 powders with the size of 40-55 nm are obtained by adding the anion surfactants in the optimal content of 1.5%(mass fraction).The effect of cationic surfactant for reducing particle aggregation is not as good as that of anion.The crystal phase constitutent of TiO2 is dependent on the temperature of thermal treatment and complete anatase can be achieved after calcining in the temperature range of 350-750℃.     

Modification of nano-TiO2 by Al2O3 in-situ coating

A novel technology of in-situ coating Al2O3 on the surface of H4TiO4 was developed to prevent the aggregation of nano-TiO2 powders and improve the dispersibility and thermal stability in the way of forming a uniform coating layer. The heterogeneous nucleation was conducted to prepare the precursor of nano-TiO2 and then Al2O3 was coated on the surface of precursor. The effects of Al2O3 in-situ coating on the properties of nano-TiO2 were investigated. The results show that H4 TiO4 can be dispersed well under alkaline condition （pH 8. 5） and the heterogeneous nucleation can be controlled easily. The optimized uniform coating layer is obtained by adding 5 % （mass fraction ） and 10% of Al2O3 and the aggregation of nano-TiO2 powders is effectively inhibited and the dispersibility is obviously improved. The crystal sizes of TiO2 powders are 12.3, 11.4 and 8. 7 nm after coating 0, 5% and 10% of Al2O3 respectively. Al2O3 on the surface of particulates in amorphous phase could increase the thermal stability of nano-partieles after calcined at 550℃.     

从贫化电炉渣浮选尾砂中氨浸铜的动力学研究

研究了采用(NH4)2CO3-NH3·H2O体系从湖北大冶某冶炼厂电炉渣浮选尾砂中浸出铜,考察了炉渣粒度、浸出温度、氨水浓度、固液质量体积比、碳酸铵用量、搅拌速度等因素对铜浸出率的影响。试验获得从电炉渣浮选尾砂中浸出铜的最佳条件为:炉渣粒度0～0.045mm,浸出温度80℃,氨水质量浓度70g/L,固液质量体积比1∶10,碳酸铵用量1.5g,搅拌速度500r/min。浸出过程前、后期受固膜扩散控制,浸出中期受扩散与化学反应共同控制。     

基于级联卷积神经网络的高效目标检测方法

目标检测作为计算机视觉的重要研究方向,在智慧城市、无人驾驶等领域的作用越来越重要.传统目标检测算法中,根据交并比(Intersection over Union,IOU)的大小判断正负样本,但较低的IOU会引入噪声,降低检测器的精度;较高的IOU会保留少数高质量样本,造成过拟合;并且推荐区域和检测器的IOU阈值相差过大...     

江西某红土镍矿冶炼炉渣作水泥混合材

研究了江西某红土镍矿冶炼炉渣作为水泥混合材使用的可行性。研究结果表明：炉渣放射性和浸出毒性远小于国家标准限值,不具有危险性,属于一般工业固体废物,作为建筑材料原料不会影响产品使用;炉渣火山灰活性合格,具有潜在的水硬性,是一种活性混合材;经稳定化处理后,掺加炉渣的水泥压蒸安定性合格,随着炉渣掺量的增加,水泥胶砂强度逐渐降低;对不掺炉渣和掺入30%炉渣的净浆28 d试块的XRD图谱和SEM图谱进行了分析,指出了对净浆试块性能产生影响的原因。     

赤泥的微结构及其分形维数的研究

赤泥微观性质的研究报道较少。本文通过氮气吸附-脱附试验研究,得到了赤泥孔结构参数,研究了四种不同的赤泥样品的孔径分布、比表面积和孔容等孔结构变化,并利用等温吸附数据计算赤泥颗粒的分形维数。结果表明:赤泥的颗粒是分形的,分形维数D在2.75～2.82之间,客观定量表征了赤泥粒度分布的结构特征。     

Preparation of titanium dioxide/silver sulfate powder and its antibacterial activity

Antibacterial powders of titanium dioxide/silver sulfate were produced by heat-treatment of the metatitanic acid, as precursor, into which the silver nitrate was added. The influences of heating temperature on the structure and composition of the product were investigated through XRD and SEM. The results show that the powder is spherical in the phase of TiO2-Ag2 SO4. The granularity of the particles increases from 10.7 nm to 28.7 nm with the temperature of heat-treatment increasing from 300 ℃ to 800 ℃. The antibacterial activity of the powder was judged in the way of the minimum inhibitory contents (MiCs). When the content of silver sulfate is less than 2%, the photocatalysis of titanium dioxide and silver ions cooperate to kill bacteria. And the MiCs decrease and keep around 1.0× 10-4- 1.5 × 10-4 constantly with the increase of silver content. Furthermore, the MiCs decrease with the increase of temperature of heat-treatment when the temperature is lower than 500 ℃. But when the temperature is beyond 600 ℃ the MiCs increase quickly, which shows the inferior antibacterial performance.     

载银二氧化钛光催化杀菌性能的研究

以偏钛酸为前驱体,浸渍一定浓度的硝酸银溶液,用热沉积法制备出载银二氧化钛。用XRD测定载银二氧化钛的结构,扫描电镜观测形貌,研究了载银量、光强、二氧化钛浓度、细菌浓度对光催化杀菌的影响。结果表明:制备的粉体为超细锐钛矿型二氧化钛,颗粒为均匀的类球形,粒度约为100～200nm。在二氧化钛颗粒上负载约1.6%的银可以扩展光源利用范围至可见光,光催化作用与银协同杀菌;但银量过高,则主要体现银的杀菌效果。光强增加,杀菌效果提高;二氧化钛的浓度为1.5g/L时杀菌效果最好;细菌浓度低于106细胞/mL时,载银二氧化钛杀菌率可以达到90%以上。     

多层复合组织在SVR 123SP横机上的设计

阐述多层复合组织的设计原理,基于SVR 123SP横机的夹纱编织技术,设计开发谷波夹纱组织、提花夹纱组织以及仿梭织风格组织3款多层复合组织针织面料。详细介绍原料规格、组织设计及编织原理,并指出多层复合组织的研发要点以及应用方向,对企业研发该类产品具有一定的指导意义。     

半圆裙廓型美感与面料性能的关系探究

为研究半圆裙外观廓形的美感与面料的性能存在的关联性,选取12种半身裙常用的面料样本,以相同的结构制作出样衣,利用数码相机拍摄其正面、侧面、背面及下面的轮廓,以裙下摆波节数为主要参数分析其与面料经纬密度、克重、悬垂系数之间的关联性。结合主观评价法,由20位服装专业人员对半圆裙样本廓形的美观程度进行评分。结果表明:经纬密度、克重对波节数影响最大,斜纹组织、含羊毛成分材质、波节数小的半圆裙被认为造型更加优美。