滑动式Lagrange插值法在BDS星历插值中的应用分析

该文利用滑动式Lagrange插值算法,从三个方面对BDS三种星历进行了内插精度分析,并与传统La-grange插值算法做了比较.首先对比相同阶数下两种算法的非端点处插值结果的精度;其次考虑端点龙格现象,分析两种方法的端点插值结果的精度;最后根据计算结果的均方根误差,分析插值结果整体精度的大小,并采用BDS精密星历数据...     

国产热模锻压力机的创新研究及应用选型

重点介绍了本公司热模锻压力机的最新研究成果,以及热模锻压力机在精锻领域自动化批量生产中的应用优势,并论述了生产应用中的选型策略.     

不同粒度气煤和瘦煤参与配煤炼焦比较

通过对气煤瘦煤煤质特征、胶质层测试后焦块形貌和焦炭光学组织进行比较,表明气煤与瘦煤成焦惰性结构高,配煤炼焦中起瘦化作用,但气煤瘦煤的结焦特性完全不同,气煤的反应活性较瘦煤高.通过对不同粒度气煤瘦煤自黏结强度和成焦显微结构特征进一步比较,表明气煤参与配煤炼焦粒度不宜过大,也不宜过小,应控制合理范围,利于焦炭质量提高;瘦煤参与配煤炼焦,应通过适度地细粉碎,利于焦炭质量提高.     

Mass transfer simulation on pervaporation dehydration of ethanol through hollow fiber NaA zeolite membranes

A multi‐layer series‐resistance mass transfer model was developed to simulate mass transfer behaviors of water/ethanol mixture through hollow fiber NaA zeolite membranes. The mass transfer through zeolite layer was described by Maxwell‐Stefan mechanism based on adsorption and diffusion parameters obtained from molecular simulation. The mass transfer through asymmetric hollow fiber support was described by dusty gas model involving Knudsen diffusion and viscous flow. It was found that the sponge‐like layer of support besides of zeolite layer made an important contribution to overall membrane transfer resistance while the finger‐like layer had less effect. When permeate pressure shifted from 0.2 to 7.5 kPa, the mass transfer resistance contribution of sponge‐like layer varied from 27.1 to 17.8%. Effects of microstructure parameters of support on mass transfer through membrane were investigated extensively. Large pore size and thin thickness for sponge‐like layer of support were beneficial to improve water permeation flux. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2468–2478, 2016     

Nano‐engineered nickel catalysts supported on 4‐channel α‐Al2O3 hollow fibers for dry reforming of methane

A nickel (Ni) nanoparticle catalyst, supported on 4‐channel α‐Al₂O₃ hollow fibers, was synthesized by atomic layer deposition (ALD). Highly dispersed Ni nanoparticles were successfully deposited on the outside surfaces and the inside porous structures of hollow fibers. The catalyst was employed to catalyze the dry reforming of methane (DRM) reaction and showed a methane reforming rate of 2040 Lh^?1gNi^?1 at 800°C. NiAl₂O₄ spinel was formed when Ni nanoparticles were deposited on alpha‐alumina substrates by ALD, which enhanced the Ni‐support interaction. Different cycles (two, five, and ten) of Al₂O₃ ALD films were applied on the Ni/hollow fiber catalysts to further improve the interaction between the Ni nanoparticles and the hollow fiber support. Both the catalyst activity and stability were improved with the deposition of Al₂O₃ ALD films. Among the Al₂O₃ ALD coated catalysts, the catalyst with five cycles of Al₂O₃ ALD showed the best performance. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2625–2631, 2018     

萜烯树脂乳液对聚氨酯乳液性能的影响

分别采用预聚法和直接乳化法制备了水性聚氨酯乳液和萜烯树脂乳液,讨论了萜烯树脂乳液的用量对聚氨酯乳液及胶膜性能的影响。结果表明,当加入萜烯树脂乳液质量分数为25%时,聚氨酯乳液的粘度和胶膜的拉伸强度均达到最大值,分别为20.1mPa.s和15.70MPa,胶膜伸长率达到377%,其用量再增大时,伸长率增加不明显;胶膜剥离强度在萜烯树脂乳液质量分数为30%时达到最大值9.87N/cm;当萜烯树脂在质量分数低于20%时,胶膜吸水率变化较小,超过20%后胶膜吸水率增大。     

ECR微波等离子体对单晶金刚石表面的碳纳米墙修饰

利用电子回旋共振(ECR)微波等离子体,在CH₄/H₂体系下,对高温高压单晶金刚石表面进行了碳纳米墙修饰。通过等离子体发射光谱研究ECR等离子体内基团的谱线强度在不同工作气压、CH₄浓度下的变化规律,结合扫描电子显微镜对单晶金刚石表面的微观形貌进行分析,进一步研究了工作气压和CH₄浓度对碳纳米墙修饰结果的影响。结果表明:碳纳米墙的取向性受工作气压影响大,低气压(0.07 Pa)条件下生长的碳纳米墙垂直取向明显,金刚石表面也出现垂直刻蚀形貌;在高气压(5 Pa)条件下生长的碳纳米墙取向性较差。同时,碳纳米墙生长的临界CH₄浓度也与工作气压有关:低气压条件下碳纳米墙生长的临界CH₄浓度高,工作气压为0.07 Pa时,碳纳米墙生长的临界CH₄浓度为3%;工作气压升至5 Pa时,碳纳米墙生长的临界CH₄浓度降为1%,碳纳米墙密度随CH₄浓度升高而增大。      

130t/h循环流化床锅炉给煤系统改造

为解决锅炉的不稳定性对化工系统的影响,对两台循环流化床锅炉的给煤系统进行改造和完善。从改造后锅炉的运行情况来看,改造效果十分明显,蓬煤、堵煤次数大幅减少,从根本上杜绝了因给煤系统故障造成系统停车事故的发生。     

PAN/CoFe_2O_4纳米复合物的制备及表征

以硝酸铁、硝酸钴和柠檬酸为原料,通过溶胶-凝胶微波加热自蔓延燃烧法制备出了纯的立方尖晶石型铁酸钴(CoFe2O4)纳米粒子,然后通过原位聚合将聚苯胺(PAN)对所得粒径约20～30nm铁酸钴纳米粒子进行了包覆,制得了PAN/CoFe2O4纳米复合物。通过傅里叶变换红外光谱(FTIR)、透射电子显微镜(TEM)、X射线衍射(XRD)等测试手段对所得产物的形貌和结构进行了表征。结果表明,PAN链段与CoFe2O4纳米粒子之间存在作用力,通过原位聚合制得的PAN包覆在CoFe2O4纳米粒子表面,X射线粉末衍射和红外光谱进一步证实了PAN/CoFe2O4纳米复合物的形成。荧光分析结果表明,引入CoFe2O4纳米粒子后PAN荧光强度增强。     

地区电网无功电压分布式控制策略

随着电力系统调度模式划分为调度中心与集控站两个层次后,原有的区域电网无功电压自动控制系统已不适应新的调度模式要求．针对新模式,提出了一种能够解决新模式下的电网无功电压分布式控制模式和控制策略．该控制策略采用分布式技术及混合优化技术,将传统的集中控制系统扩展为分布式二级控制．由凋度中心对全网的无功电压进行计算,提出对应的控制策略,由各个集控站根据调度中心发出的指令,执行相关的动作,实现全网无功电压的优化运行．