磷酸二氢铝对高铬耐火泥浆性能的影响

选用工业级电熔氧化铬粉、氧化铬绿以及α-A l2O3细粉等为原料,以磷酸二氢铝(w(P2O5)≥65%,w(A l2O3)≥17%)作为高铬泥浆的结合剂,研究了磷酸二氢铝加入量对不同系列(电熔氧化铬粉和氧化铬绿的加入量不同)泥浆加水量、粘结时间和粘结强度的影响,并对磷酸二氢铝的作用机理进行了分析。结果表明,随着磷酸二氢铝加入量的增大,泥浆的加水量降低,粘结时间延长,粘结强度提高。     

《电子商务概论》课程教学方法初探

当前,电子商务已成为各国经济的主要商务形态,为了适应社会需求,大多高校已经开设了电子商务概论课程及电子商务专业。本文对电子商务概论课程的教学方法进行了分析和讨论,针对电子商务概论课程教学的现状,提出了当前电子商务概论课程教学存在的问题,讨论了电子商务概论课程的教学方法及教学手段的改进办法。     

Double core---shell nanostructured Sn---Cu alloy as enhanced anode materials for lithium and sodium storage

Sn-based alloy materials are considered as a promising anode candidate for lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs), whereas they suffer from severe volume change during the discharge/charge process. To address the issue, double core–shell structured Sn–Cu@SnO₂@C nanocomposites have been prepared by a simple co-precipitation method combined with carbon coating approach. The double core–shell structure consists of Sn–Cu multiphase alloy nanoparticles as the inner core, intermediate SnO₂ layer anchored on the surface of Sn–Cu nanoparticle and outer carbon layer. The Sn–Cu@SnO₂@C electrode exhibits outstanding electrochemical performances, delivering a reversible capacity of 396 mA·h·g⁻¹ at 100 mA·g⁻¹ after 100 cycles for LIBs and a high initial reversible capacity of 463 mA·h·g⁻¹ at 50 mA·g⁻¹ and a capacity retention of 86% after 100 cycles, along with a remarkable rate capability (193 mA·h·g⁻¹ at 5000 mA·g⁻¹) for SIBs. This work provides a viable strategy to fabricate double core–shell structured Sn-based alloy anodes for high energy density LIBs and SIBs.     

锆英石质耐火材料的X射线荧光光谱分析法

以少量自然标样与光谱纯氧化锆配制出锆英石标样系列 ,采用混合熔剂熔融制样 ,用DJ数学模型的经验系数法校正基体效应 ,建立了锆英石质耐火材料的X射线荧光光谱分析法。该分析方法的精密度和准确度完全可与化学法媲美。     

接触路径对弧齿锥齿轮接触应力和弯曲应力的影响

采用TCA、LTCA及弹性理论综合分析的方法研究了接触路径对弧齿锥齿轮接触应力的影响，利用有限元应力影响矩阵法分析了齿根弯曲应力状态，实验测定了接触路径倾斜度不同的弧齿锥齿轮的齿根弯曲应力。数值仿真与实验都证明，通过倾斜接触路径得到的高重合度弧齿锥齿轮齿面载荷分布合理，在强度方面具有明显的优越性。     

高重合度弧齿锥齿轮加工参数设计与重合度测定

给出了高重合度弧齿锥齿轮的加工参数设计方法。利用局部综合法、轮齿接触分析(TCA)、轮齿承载接触分析(LTCA)和啮合仿真技术,通过齿面接触路径倾斜,达到了高重合度的设计目的。该设计方法不改变轮坯的几何参数,不改变大轮的加工调整参数,可在现有的机床上使用标准系列刀具加工,实用性强。给出了三种齿面接触路径倾斜度不同的设计方案,进行了啮合仿真分析与重合度测定,结果证明,用该方法可设计出重合度达2.0～3.0的高重合度弧齿锥齿轮。     

EFFECT OF CeO_2 ON MICROSTRUCTURE AND WEAR RESISTANCE OF LASER REMELTED FeBSi COATING

The hardness and wear resistance of sprayed FeBSi coating after laser remelting weremuch improved by addition of 8 wt-% CeO_2.Microstructural observation on theFeBSi+CeO_2 coating revealed that the formation of martensite occurs,as well as therefined grains and the more eutectic and compounds with regular morphology are dis-tributed.While the FeBSi coating free from CeO_2 is a sharp constrast in microstructure.     

REVERSIBLE TRANSFORMATION BETWEEN MATRIX AND MARTENSITE IN Ni-Ti SHAPE MEMORY ALLOYS

The reversible transformation between matrix and martensite in Ni-Ti shape memory alloyshas been dynamically observed under TEM.The orientation relation between martensite andaustenite as well as the structural change near the transition temperature has been also studiedwith the help of HREM SADP.The results show that the orientation relation betweenmartensite and austenite is[(?)11]_A//[(?)10]_M,[110]_A//[001]_M,(110)_A//(001)_M and theangle between((?)110)_A and(010)_M is about 6.5°.The crystal defects of martensite are foundto be twin and stacking fault,and the twin plane as(100).     

首台国产15CrMo加氢反应器的试制

介绍了首台国产１５ＣｒＭｏ 加氢反应器的设计和制造工艺特点以及相关的实验研究情况。