MnOx-M/AC(M=La,Ce,Co,Ni)氧还原催化材料的制备及性能

用热解法制备了掺杂La、Ce、Co、Ni等元素的氧还原催化材料MnOx/AC,并采用XRD和电化学方法对所制备材料的性质和电化学反应性能进行了表征。结果表明,掺杂适量的La、Ce、Co和Ni等元素可改善电极的氧还原反应性能。掺杂La和Co元素的MnOx/AC氧催化还原性能最好,其中,在50mA/cm2的电流条件下,使用这两种掺杂材料所制备的模拟锌-空气电池的放电电压分别为1.1236V和1.1246V。     

液晶显示屏中液晶层的等效分析模型

文章采用复合材料力学的分析方法,建立了正交各向异性的液晶层等效模型;利用有限元法分析了简化液晶屏的三维模型和等效模型,检验了液晶层等效模型的有效性;针对正交各向异性和各向同性2种液晶层等效模型,计算并比较了液晶屏中的热应力和热位移。结果表明:液晶屏在受温度载荷作用时,文中所建立的液晶层等效模型与实际结构吻合得很好;在受力作用时,等效模型会产生一定的误差;在液晶屏的热应力计算时,2种液晶层等效模型的应力和位移均有一定的差别。     

钢-砼结合梁温度应力的弹性力学解

采用弹性理论的半逆解法,视静定钢-砼结合梁为平面应力问题,将应力函数取为三角级数,考虑钢与混凝土的相对滑移,推导了钢-砼结合梁在一般温度分布作用下的应力公式。最后,通过算例,计算了钢-砼结合梁在温差、日照温度变化和骤然降温三种工况下的温度应力。     

Structures and Properties of Composite Yarns of Filaments and Wool Staple Fibers

More and more composite yarns of filament and wool staple fiber have been applied to develop the new type of fabrics. However, the great difference in yarn structures between the composite yarns and conventional staple yarns does affect the properties of yarns and fabrics. In this paper, it has been studied that the differences of the composite yarn properties of tensile, bending rigidity, torsional rigidity, the hairiness and irregularity etc.     

High Oil-absorptive Composites Prepared from Non-woven Fiber and Sponges with 4-tert- butylstyrene-EPDM-divinylbenzene Graft Polymer

4-tert-butylstyrene-EPDM-divinylbenzene graft terpolym-er (PBED) was prepared by graft cross-polymerization in toluene using BPO as an initiator. The gel-PBED and sol-PBED were isolated from extraction of tetrahydrofuran (THF), and then they were identified by IR spectr-oscopy. The maximum oil-absorptivity of gel-PBED produced from the optimum reaction conditions was 8420% but its swelling rate was very low. The highest oil-absorptivity of photocrosslinked sol-PBED film was 5 800%. Although its oil absorbency was not as high as gel-PBED' s, swelling rate was higher than that of gel-PBED and was suitable for commercial purpose. After swelling in oil, neither gel-PBED nor photocrosslinked sol-PBED film having high oil-absorptivity had sufficient mechanical strength to be taken out of oil wholly. As is known, composite technique is one of the useful methods for reinforcing them. Fibers, sponges and non-woven cloths were used as reinforcers or supporters in this work. Oil-absorptivities and swelling kinetics     

GT35钢结硬质合金材料镜面加工的试验研究

钢结硬质合金是一种组织结构特殊的难加工材料，难以获得超精和镜面加工表面质量。本文用三种方法对ＴＧ３５进行镜面加工试验研究，取得良好效果。传统研磨工艺宜采用高刚性研磨工具和金刚石研磨粉，以减轻对基体材料软硬组织的选择去除现象；以高刚度精密度床及专用装置的基础的ＥＬＩＤ磨削方法可获得良好的加工表面；固体磨料研磨方法以春无序研磨轨迹，在微量去除时可有效获得极低的表面粗糙度。     

不同水/表面活性剂比的微乳液制备纳米Ni-Fe复合微粒的组成和粒径分布

用X－射线衍射（XRD）和透射电子显微镜（TEM）等研究了不同水／表面活性剂（[W]/[S]）比的微乳液制备纳米Ni-Fe复合微粒的组成和粒径分布，结果表明，([W]/[S]）比值不同，得到的Ni-Fe复合物微粒不但粒径不同，而产物的组成也有差异，当([W]/[S]）＞240时，微粒粒径最小，但组成复杂；当([W]/[S]）＜198时，微粒粒径呈寺大，但组成较单一，且可得到Ni-Fe合金相，各样品磁参数的测量表明，当将Ni-Fe组分总量规一化时，发现随Ni/Fe比增加，磁参数减小。     

High Oil-absorptive Composites Prepared from Non-woven Fiber and Sponges with 4-tert- buty1styrene-EPDM-divinylbenzene Graft Polymer

4-tert-butylstyrene-EPDM-divinylbenzene graft terpolymer (PBED) was prepared by graft cross-polymerization in toluene using BPO as an initiator. The gel-PBED and solPBED were isolated from extraction of tetrahydrofuran (THF), and then they were identified by IR spectroscopy. The maximum oil-absorptivity of gel-PBED produced from the optinum reaction conditions was 8 420% but its swelling rate was very low. The highest oil-absorptivity of photocrosslinked sol-PBED film was 5 800%. Although its oil absorbency was not as high as gel-PBED' s, swelling rate was higher than that of gelPBED and was suitable for commercial purpose. After swelling in oil, neither gel PBED nor photocrosslinked sol-PBED film having high oil-absorptivity had sufficient mechanical strength to be taken out of oil wholly. As is known, composite technique is one of the useful methods for reinforcing them. Fibers, sponges and non-woven cloths were used as reinforcers or supporters in this work. Oil-absorptivities and swelling kinetics were evaluated by method ASTM (F726 - 81 ) and an experimental equation. The mechanical properties and the morphologies of some composites were measured by tensile tester and SEM , respectively.     

求关系模式所有最小基数候选关键字的一种多项式算法

本文深入分析了最小基数候选关键字在关系模式中的结构特征,提出了化简独立复合环、独立简单环、化简双部属性函数依赖图等概念.在此基础上,给出了求一个关系模式所有最小基数候选关键字集的多项式算法.     

多节状SiC晶须的合成及在矿冶工程材料中的应用

运用TEM、XRD等分析检测技术对SiCw的形貌结构、长度与直径分布及其应用于复合材料中的特性进行了检测。研究表明：SiCw产品以直晶为主，表面呈多节状，以-SiC为主要晶型，直径为0.2～1.5m,长度为30～200m。此外，作者对SiCw在矿冶工程材料中的应用进行了展望。