Synthesis,Crystal Structure and Theoretical Calculation Studies on 1-(4-chloromethylbenzoyl)-3-(mono-substituted) thioureas

The derivatives 1-(4-chloromethylbenzoyl)-3-(4-nitrophenyl) thiourea(1) and 1-(4-chloromethylbenzoyl)-3-(benzothiazole-2-yl) thiourea(2) were synthesized and characterized by X-ray single-crystal diffraction and basic spectroscopic methods(~1H NMR, FT-IR, Mass spectra, elemental analyses, UV-vis). Compound 1 crystallizes in monoclinic space group P2_(1/c) with a = 4.5380(14), b = 17.504(5), c = 19.229(6) ?, b = 91.351(7)o, C_(15)H_(12)ClN_3O_3S, M_r = 349.79, V = 1527.0(8) ?~3, Z = 4, D_c = 1.521 Mg?m~(-3), μ = 0.405 mm~(-1), F(000) = 720, the final R = 0.1130 and wR = 0.3621 for 2032 observed reflections with I 2σ(I). And compound 2 crystallizes in triclinic space group P~-_1 with a = 4.5463(18), b = 14.898(6), c = 15.118(6) ?, α = 115.519(5)o, β = 98.267(6)o, γ = 94.031(7)o, C_(16)H_(12)ClN_3OS_2·CH_3OH, M_r = 393.90, V = 904.4(6) ?~3, Z = 2, D_c = 1.446 Mg?m~(-3), μ = 0.458 mm~(-1), F(000) = 408, the final R = 0.0657 and wR = 0.1812 for 2200 observed reflections with I 2σ(I). In order to study the mechanism of intermolecular interactions more accurately, the Hirshfeld surface analyses and 2D fingerprint plots of the two compounds were performed to further understand the intermolecular short contact, including hydrogen bonds. The UV-Vis spectra were also predicted together with different HOMO-LUMO orbitals to analyze the characteristics of the electronic transition within 1 and 2. Finally, the electrostatic potentials(ESP) surfaces with extremes, as well as distribution of van der Waals surface area related to the range of different ESP values were calculated.     

蒸汽流速对竖直管外Marangoni凝结换热特性影响的实验研究

本文在不同蒸汽流速下对水-酒精混合蒸汽在竖直管外Marangoni凝结换热特性进行了实验研究.结果表明:在相同蒸汽压力下,混合蒸汽在竖直管外凝结换热系数随蒸汽流速的增加而增加.当蒸汽酒精浓度较低时(1%、2%、5%),凝结换热系数随流速的增加而明显增加.当蒸汽酒精浓度较高时(20%、50%),流速的增加对凝结换热系数影响较小.这主要是由于蒸汽流速在低酒精浓度下对凝结扩散层热阻的影响大于在高酒精浓度下对扩散层热阻的影响.     

长链支化聚丙烯结晶行为及发泡性能研究

通过广角X射线衍射(WAXD)、示差扫描量热(DSC)和偏光显微镜(POM)研究了长链支化聚丙烯(LCBPP)和线性等规聚丙烯(PP)的结晶行为.WAXD和DSC的结果显示LCBPP样品有利于β结晶,出现了少量β晶.DSC和POM的结果显示在等温结晶过程中长链支化结构起到促进异相成核和细化晶粒的作用,LCBPP样品的结晶温度提高,结晶速度增大,球晶尺寸显著减小.采用间歇釜式超临界二氧化碳发泡法对LCBPP和线性PP样品进行发泡,由于LCBPP结晶温度高,结晶速率更快,有利于泡孔的固化定型,可以提高发泡温度,研究结果表明在相同的发泡压力下LCBPP样品发泡温度窗口较宽,为5 K左右,而线性PP样品的发泡温度窗口较窄,仅为2 K左右,同时在相同的发泡条件下LCBPP样品的发泡倍率较大.     

碳纤维布载三维网状聚苯胺在RCl(R=H,Li,Na,K)水溶液中的电容性能对比

通过电化学聚合法制备了碳纤维布载三维网状聚苯胺电极,采用扫描电子显微镜、傅里叶红外光谱仪和X射线光电子能谱仪观察了电极形貌,并分析了电极表面特征基团。 接着,对比研究了该电极在4种RCl(R=H,Li,Na,K)水溶液中的电容性能。 电化学测试表明,在KCl中的电势窗口(1.8 V)大于在HCl和LiCl中的电势窗口,且在KCl中的比电容(501 F/g@0.5 A/g)远远大于NaCl中的比电容;即使在10 A/g的充放电电流下,电极在KCl溶液中的能量密度仍高于HCl溶液中2.0 A/g下的能量密度,因此KCl为聚苯胺基电容器最佳的电解质类型。 本文通过简单地改变水系溶液中电解质的种类,即可达到拓宽电势窗口、显著提升电化学电容器能量密度的目的,避免了使用有机溶液带来的物理化学稳定性差、污染环境的问题。     

不同压力下竖直管外Marangoni凝结换热特性研究

本文在不同压力状态下对水与酒精混合蒸汽在竖直管外Marangoni凝结换热特性进行了可视化实验研究,观测到不同过冷度下的凝结状态.实验结果表明,在相同流速和浓度条件下,酒精浓度较低时凝结换热系数随蒸汽压力的升高而升高.但在高酒精浓度下,凝结液表面张力梯度减小,扩散热阻的影响增大,蒸汽压力对于凝结换热系数的影响并不明显.     

考虑支承的大跨度索膜结构整体分析与设计

基于修正的拉格朗日法,建立非线性有限元平衡方程,介绍了空间梁单元非线性刚度矩阵。针对此类结构在形态分析及设计中的难点问题,提出利用定力单元、定形单元和微调单元建立数值模型。采用AutoCAD二次开发工具ObjectARX编制有限元软件,能够进行考虑支承的大跨度索膜结构整体分析与设计。以芜湖体育场为工程背景,进行了形态分析和长期荷载组合下的反应。计算结果表明,本文所提方法和有限元软件显著地提高了设计工作的效率,并能准确地获得满足设计要求的结构初始形态及受力分析数据,便于实际工程的设计应用。     

强Prüfer环的同调刻画

设R是环,R的小finitistic维数定义为fPD(R)=sup{pd_RM|M∈FPR}.本文证明了:若R是连通的强Prüfer环,则fPD(R)≤1.也证明了若R是强Prufer环,M∈FPR,且M是Q-挠模,则pd_RM≤1.     

数智物联岩石力学背包实验室的自主创新

简要阐述了岩石力学试验装备的发展历史,介绍数智物联岩石力学背包实验室自主创新历程,重点总结了该设备相较于传统设备存在的优势.数智物联岩石力学背包实验室能够大幅度提升工作效率与信息化水平,工作现场更具便捷化和智能化.背包实验室的新理念,为实际工程提供新思路,相较传统试验更节约时间成本、人员成本、材料成本,是工程仪器未来的...     

Passive ranging and a three-dimensional imaging system through wavefront coding

A single-image passive ranging and three-dimensional(3 D) imaging system with chiral phase encoding was proposed in 2011 [Opt. Lett. 36, 115(2011)]. A new theoretical analysis of the system in space domain is presented in this paper. We deduce the analytic relationships between the object distance and the point spread function, and between the object distance and the encoded image, respectively. Both the point spread function and the processed spectrum of the encoded image have two spots, which will rotate with the variation of the object distance. Then the depth map is extracted from the encoded image and it can be used to set up 3 D images. The theoretical analysis is verified by a wavefront coding system with a chiral phase which is generated by a phase-only liquid-crystal spatial light modulator. The phase generated by the liquid-crystal spatial light modulator is more flexible than the fixed phase mask and can be adjusted in real time. It is especially suitable for observing the object with a large depth of field.