Evolution of Ti （C, N）-based cermet microstructures

Two series of Ti(C, N)-based cermet materials originating from the same chemical composition but with dif-ferent grain size distribution and sintered to different stages of the sintering cycle have been studied using SEM, TEM,EDX, and XRD. Much of the surrounding structure is formed during solid state sintering. During the solid state sintering, at first, the Mo and W rich (Ti, Mo, W)C inner rim is formed by the interaction among TiC, WC, and Mo2C; then the Mo and W lean (Ti, Mo, W)(C, N)outer rim is formed. During the liquid phase sintering, the outer rim of coarse grains grows rapidly throw a solution-reprecipitation process; aLso coarse grains grow by particle coalescence. The interface between coarse grain outer rim and binder is flat (crystal surface).     

含乙烯基液态超支化聚碳硅烷的合成、表征及陶瓷化

采用"有核慢滴加法",以1,1,3,3-四氯-1,3-二硅丁烷(Cl2SiHCH2SiCl2CH3)为核,氯甲基三氯硅烷(Cl3SiCH2Cl)、乙烯基氯化镁(CH2=CHMgCl)为单体,经过格式偶联反应和还原反应制备了含乙烯基的液态聚碳硅烷(VHPCS)。利用FT-IR、NMR、GPC、TGA、XRD与SEM等对VHPCS及其陶瓷产物进行了表征。结果表明,VHPCS具有超支化结构,热解能得到较致密的SiC陶瓷,1000℃陶瓷产率为85.9%(质量分数,下同),1200℃陶瓷产物开始出现β-SiC微晶。     

溶胶-凝胶法制备AA5052系铝合金耐蚀性保护膜

采用乙烯基三乙氧基硅烷(VS)和正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶法在AA5052铝合金表面制备了倍半硅氧烷(SSO)杂化膜。采用动电位极化法和电化学阻抗法测试了膜层的耐腐蚀性能,并考察了正硅酸乙酯的含量对其膜层的影响。结果表明,杂化膜能有效抑制AA5052铝合金的腐蚀反应,且当正硅酸乙酯的含量为20%时,杂化膜涂层的耐腐蚀性最好。     

脉冲磁致振荡(PMO)技术在ZTM-S2合金工具钢连铸坯生产中的应用

研究了脉冲磁致振荡(pulse magneto-oscillation,PMO)技术在ZTM-S2合金工具钢连铸坯生产中的应用效果.研究表明:经过PMO处理后,ZTM-S2工具钢连铸坯的等轴晶面积分数从原来的22.3％增加到了34.8％,提高了56.1％;其中心碳偏析指数从原来的1.21下降至1.13,降低了6.6％....     

Pt改性Ni3Al基合金短时高温氧化行为研究

用冷坩埚悬浮熔炼制备了Ni-xPt-25Al(x=0,10,20,30,at%)系列合金,利用X射线衍射仪、同步热分析仪、扫描电镜和光电子能谱仪(XPS)分析了Pt的添加对晶体结构的影响,研究了Ni-xPt-25Al合金的氧化动力学曲线、氧化物形貌以及抗氧化性能。结果表明:随着Pt含量的升高,Pt改性Ni_3Al基合金仍保持γ′相。升温过程和短时等温阶段合金的氧化动力学特征分别符合线性和抛物线氧化物生长动力学规律。Pt有利于氧化物的快速形成,且随Pt含量的增加,氧化膜的完整性和致密性均有所改善。     

环保膨胀型阻燃PP母料的研制

以三聚氰胺聚磷酸(MPP)/季戊四醇(PT)为复配阻燃剂,氧化锌为催化协效剂,聚乙烯蜡为分散剂,并添加一定量载体树脂,制备了环保膨胀型阻燃聚丙烯(PP)母料,运用氧指数法、UL94垂直燃烧法、热失重分析法和扫描电子显微镜研究了阻燃PP母料的阻燃性能。结果表明:当MPP∶PT=2∶1且MPP与PT占母料总量的72%时,将该类母料添加到PP中制得的复合材料的综合性能最好;阻燃PP母料的最佳载体树脂为PP/PP-g-MAH(1/1),将25%PP/PP-g-MAH基阻燃PP母料添加到PP中,复合材料的阻燃等级可达到UL94V—0级。     

《漆膜耐湿热测定法》标准修订情况介绍

介绍了GB/T 1740-79（89）《漆膜耐湿热测定法》修订前后的主要技术差异。     

小振幅振荡剪切法测量PP/(E/VAC)共混物的界面张力

借助于动态流变学中小振幅振荡剪切法测得聚丙烯(PP)与两种不同牌号(乙烯/乙酸乙烯酯)共聚物(E/VAC)共混物的动态模量,通过扫描电子显微镜对共混物中分散相粒径及分布进行表征,将实际测得的共混物动态模量与用Palierne乳液模型计算得到的共混物动态模量进行数据拟合,得到PP与两种不同牌号E/VAC共混物的界面张力分别为0.44 mN/m和1.39 mN/m。     

炼厂生产计划优化模型

This article addresses a production planning optimization problem of overall refinery. The authors formulated the optimization problem as mixed integer linear programming. The model considers the main factors for optimizing the production plan of overall refinery related to the use of run-modes of processing units. The aim of this planning is to decide which run-mode to use in each processing unit in each period of a given horizon, to satisfy the demand, such as the total cost of production and inventory is minimized. The resulting model can be regarded as a generalized lot-sizing problem where a run-mode can produce and consume more than one product. The resulting optimization problem is large-sized and NP-hard. The authors have proposed a column generation-based algorithm called branch-and-price （BP） for solving the interested optimization problem. The model and implementation of the algorithm are described in detail in this article. The computational results verify the effectiveness of the proposed model and the solution method.     

乙醛水氧化生产乙酸热力学分析

醛类水氧化制酸是一种羧酸类产品生产的新型绿色合成工艺.一步反应中醛加水直接生成乙酸和氢气.分步反应中醛通过歧化得到酯,酯水解得到酸和醇,醇脱氢得到醛,以酯和醇为中间产物,终产物为酸和氢气.对乙醛水氧化反应进行了详尽的热力学计算.讨论了水醛比、温度、压力对热力学平衡时组成的影响,得到了最佳理论反应温度,为600 K.水醛比的增加有利于乙酸的生成,压力的提高有利于乙酸的生成.分步反应中,在水醛比为4,压力为0.1 MPa,温度为600 K条件下,乙醛转化率97.14%,乙酸收率83.37%,乙酸选择性85.82%.