Combined effect of chemically compound graphene oxide‐calcium pimelate on crystallization behavior,morphology and mechanical properties of isotactic polypropylene

The combined nucleation effect of graphene oxide (GO) and calcium pimelate (CaPi) which are chemically compound together (expressed in GO ? CaPi) in isotactic polypropylene (iPP) was investigated. Fourier transform infrared (FTIR), X‐ray diffraction (XRD) and thermogravimetric analysis (TGA) verified that CaPi was chemically compound with GO by chelate bonds. The crystallization behavior and crystalline morphologies of iPP nucleated with different mass ratio of GO and CaPi were investigated. The crystallization peak temperature of iPP nucleated with 0.2 wt% GO ? CaPi with the mass ratio of 1:5 (GO1 ? C5) was increased by 8.3°C when compared with that of pure iPP, and the relative content of β‐crystal reached up to 0.7962. Whereas, the crystallization peak temperature of iPP nucleated with 0.2 wt% GO and CaPi which are blended together by mechanical force (expressed in GO + CaPi) with the mass ratio of 1:5 (GO1 + C5) was only increased by 5.0°C. It was attributed to that the aggregation of GO + CaPi caused the decrease of the crystallization peak temperature, while the GO1 ? C5 uniformly dispersed in the iPP matrix. Unexpectedly, the relative content of β‐crystal of iPP nucleated with 0.02 wt% GO1 ? C5 reached up to 0.8094, and the crystallization peak temperature was increased by 6.7°C compared with that of pure iPP. Meanwhile, the impact strength, tensile strength and heat deflection temperature of iPP nucleated with 0.02 wt% GO1 ? C5 increased by almost 45.86%, 2.03% and 7.7°C, respectively. The iPP nucleated with GO1 ? C5 obtained a balance between stiffness and toughness and the thermo‐mechanical property of nucleated iPP was improved.     

SiC单晶片的取向研磨

优质晶体生长常常需要籽晶或衬底偏离常规结晶取向.为便于按任意偏向角度研磨晶片,本实验室设计并应用了晶片取向研磨夹具及相应的研磨工艺.本文介绍了该夹具和工艺的工作原理、技术要点以及对技术指标的鉴定情况.测试结果表明,研磨取向误差范围可控制在5;之内,研磨片厚度偏差小于5 μm、粗糙度Ra=0.12 μm.     

纳米二氧化硅水溶胶成膜特性研究

研究了纳米SiO2水溶胶的固液二相流成膜特性．结果表明，水溶胶中的Si02固体颗粒的粒径及质量分数对粘度的影响较小，对成膜能力和承载能力的影响较大；在薄膜润滑阶段，固体颗粒的粒径和质量分数对润滑状态的稳定性具有一定的影响，随着速度的增加，液体膜厚度逐渐增大，固体颗粒对液体润滑膜稳定性及性能的影响逐渐减弱；在弹流润滑阶段，固体颗粒的影响很小。     

用于教学的局域网共享虚拟综合测试系统

随着计算机技术和网络技术的迅猛发展,虚拟实验室和网络实验室已逐渐替代了传统模式的实验室.本文探讨了电子技术教学中虚拟实验室和网络实验室的建设,给出了系统功能分析、硬件平台解决方案和网络组建模式,并且实现了局域网共享的虚拟综合测试系统的各个功能,为电子技术实验室的建设提出了一种成本较低、功能可扩、形式新颖的途径.     

硼掺杂VO2（M）纳米棒的合成、相转变及光学特性

采用V2O5和硼酸为原材料,草酸为还原剂,在水热条件下,成功制备出硼(B)掺杂VO2(B)纳米棒,经Ar气环境退火后,得到了V1-xBxO2(M)系列样品。样品的结构、形貌和相转变温度分别用X-射线粉末衍射(XRD)仪、扫描电子显微镜(SEM)和差示扫描量热仪(DSC)等进行表征。用X-射线光电子谱(XPS)来表征样品的组份和元素的价态,样品的红外光吸收谱也被测量。结果显示,当B掺杂达到2.0at%时,V1-xBxO2(M)相的转变温度升高到75.03℃。这个升高的相转变温度可归因于B3+替代V4+引起VO6八面体的晶格畸变,以及局域晶格电子密度的降低。     

A Characterization of Maximally Entangled Two-Qubit States

As already known by Rana’s result, all eigenvalues of any partial-transposed bipartite state fall within the closed interval [−12,1]. In this note, we study a family of bipartite quantum states where the minimal eigenvalues of partial-transposed states are −12. For a two-qubit system, we find that the minimal eigenvalue of its partial-transposed state is −12 if and only if such a two-qubit state is maximally entangled. However this result does not hold in general for a two-qudit system when the dimensions of the underlying space are larger than two.     

石英相二氧化硅纳米管的制备及其对Pb2+的吸附行为研究

本文采用纯化的海泡石作为硅源,在不需要模板和煅烧工艺的条件下,制备出了石英相的硅纳米管(SNTs),并对获得样品进行了XRD、FTIR和SEM等表征.制得的SNTs具有40~50 nm外径,管腔直径为10~15 nm,长度为20~100 μm.此外,研究了SNTs对于Pb2+的吸附行为.结果表明,Pb2+吸附量随初始Pb2+浓度,吸附时间,温度和溶液pH值(<5)增加而增加.在溶液pH为5时,SNTs对于Pb2+的吸附平衡的吸附焓(ΔH)和熵变(ΔS)分别为6.28 kJ/mol和69.8 J/mol· K.     

热熔还原法制备超硬复合相氮化碳及其工艺探索

本文采用热熔还原法,以聚氯乙烯、氯化铵、氧化铁为原料制备复合超硬相氮化碳(α/β-C3 N4).采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)以及透射电子显微镜(TEM)对样品进行表征.在此基础上分析了不同温度和原料配比下合成复合相C3 N4的物相组成及形貌变化.结果表明样品形貌随着原料配比的不同在颗粒、棒状、纳米线之间转变.当C、N和Fe之间摩尔比为3:4:0.4时,所制备出的样品呈纳米线状,纳米线的直径约为15 nm,结晶性良好.而在其它配比下,只能获得棒状或颗粒状α/β复合相C3 N4.     

Crystal Structures,Terahertz Spectra and Dye Adsorption Performance of Three Lanthanide-bisphosphonate Complexes Containing Keggin Polyoxometalates

Three lanthanide complexes[LnL3(H2O)]PMo12O40·CH3CN(Ln = Dy3+for 1,Ln = Ho3+for 2,Ln= Lu3+for 3,L = tetraethyl ethylenediphosphonate)have been synthesized,and c...     

Synthesis and Characterization of a Novel Podophyllotoxin Derivative Containing a Cyclohexadienone Group

4β-Azido-4-demethyl-4'-O-demethyl-epipodophyllotoxin reacted with phenyliodonium diacetate in MeOH at room temperature to synthesize a novel podophyllotoxin derivative containing a cyclohexadienone group with the original configurations of C2 and C4,which are required for the antitumor activities.The component and structure of the pro-duct were confirmed using elemental analysis,high-resolution mass spectrum,1H and 13C NMR spectra,and infrared spectrum.Furthermore,the fragmentation routes of the product were fully assigned with electron-impact time-of-flight mass spectrometry(EI-TOF MS),which can also be used for the structural elucidation based on the molecular ion at m/z 455(16%)and three novel characteristic fragment ions at m/z 183(37%),425(7%),and 199(5%).The cyclohexadienone product is sensitive to acidic media.When it is treated with a trace of acid,another novel derivative containing an orthoquinone moiety is formed,which links with the metabolism of the cancer inhibitors.