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From the implementation point of view, the printable magnetic Janus colloidal photonic crystals (CPCs) microspheres are highly desirable. Herein, we developed a dispensing-printing strategy for magnetic Janus CPCs display via a microfluidics-automatic printing system. Monodisperse core/shell colloidal particles and magnetic Fe3O4 nanoparticles precursor serve as inks. Based on the equilibrium of three-phase interfacial tensions, Janus structure is successfully formed, followed by UV irradiation and self-assembly of colloid particle to generate magnetic Janus CPCs microspheres. Notably, this method shows distinct superiority with highly uniform Janus CPCs structure, where the TMPTA/Fe3O4 hemisphere is in the bottom side while CPCs hemisphere is in the top side. Thus, by using Janus CPCs microspheres with two different structural colors as pixel points, a pattern with red flower and green leaf is achieved. Moreover, 1D linear Janus CPCs pattern encapsulated by hydrogel is also fabricated. Both the color and the shape can be changed under the traction of magnets, showing great potentials in flexible smart displays. We believe this work not only offers a new feasible pathway to construct magnetic Janus CPCs patterns by a dispensing-printable fashion, but also provides new opportunities for flexible and smart displays.  相似文献   
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随着光伏行业的快速发展, 对硅单晶的品质和长晶装备的稳定性的要求也不断提高。直拉法是生产硅单晶的主要方法,通过提高单晶炉副室的高度以扩大单晶硅的生产规模。由于副室高度的大幅增加,且单晶炉提拉头质心相对于旋转轴心有一定距离,对单晶炉整体稳定性有较大影响,从而降低了单晶硅的生产质量。针对此问题,对单晶炉建立可靠的力学分析模型,采用数值仿真方法,对单晶炉整体进行动力学响应分析,计算得到副室高度增加后的单晶炉工作时中钨丝绳下端晶棒的运动规律以及最大摆动幅度,为改进设计提供依据。数值仿真分析表明提高单晶炉副室高度后,提拉头较大的质心偏心是单晶炉提拉系统发生摆动的主要原因。在此基础上提出在提拉头上添加质心调节装置,通过控制系统调节可保证提拉头质心位置在旋转轴线上以降低提拉系统的摆动。  相似文献   
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One important prerequisite for the fabrication of molecular functional device strongly relies on the understanding the conducting behaviors of the metal-molecule-metal junction that can respond to an external stimulus. The model Lewis basic molecule 4,4′-(pyridine-3,5-diyl)dibenzonitrile (DBP), which can react with Lewis acid and protic acid, was synthesized. Then, the molecular conducting behavior of DBP, DBP-B(C6F5)3, and DBP-TfOH (DBP-B(C6F5)3, and DBP-TfOH were produced by Lewis acid and protonic acid treatment of DBP) was researched and compared. Given that their identical physical paths for DBP, DBP-B(C6F5)3, and DBP-TfOH to sustain charge transport, our results indicate that modifying the molecular electronic structure, even not directly changing the conductive physical backbone, can tune the charge transporting ability by nearly one order of magnitude. Furthermore, the addition of another Lewis base triethylamine (of stronger alkaline than DBP), to Lewis acid-base pair reverts the electrical properties back to that of a single DBP junction, that is constructive to propose a useful but simple strategy for the design and construction of reversible and controllable molecular device based on pyridine derived molecule.  相似文献   
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The tenacity of the present study was to develop a material using an economical chemical route, having balance between magnetic and dielectric order parameters for maximum transmittance of electromagnetic waves in order to use them in shielding materials. In this context, Mn-Zn ferrites were prepared using a wet chemical based sol-gel auto-combustion technique. X-ray diffraction confirmed the pure phase formation of samples, while some impurity peaks were also present for the higher value of Mn substitution. Field emission scanning electron microscopy revealed a decrease in grain size with increasing Mn substitution. While energy dispersive X-ray spectroscopy confirmed the elemental composition of pure and Mn substituted samples, the dielectric constant, dielectric loss and tangent loss were decreased with increasing frequency and increasing Mn substitution. The complex electric modulus was found to be a function of frequency and values of complex electric modulus were increased with increasing frequency and Mn substitution. The complex impedance of RC series circuit and RC parallel circuit was also decreased with increasing both the parameters while AC conductivity was increased in the series. Dielectric frequency response was also studied for the prepared samples and the best match was found with expected results. The Nyquist and Cole-Cole plots revealed the semi-conductive behavior at higher frequency and Mn substitution also yielded the same results. The relative stability of the samples to be used as dielectric materials was also studied using Bode and Nichols plots, and a comparatively high gain margin was observed, well suitable for potential applications in electromagnetic shielding.  相似文献   
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对输电塔进行合理简化可以提高塔线体系动力学仿真的效率。本文给出自立塔梁柱简化模型的计算方法,并提出利用梁柱简化模型计算方法建立自立塔塔线体系整体模型,同时采用桁梁混合模型建立精细化塔线体系整体模型,对两种模型塔线体系静力特性及振型和固有频率等动力特性进行对比分析。以脱冰工况为例,采用生死单元技术将施加在输电线节点上的集中质量单元杀死来模拟脱冰,实现对塔线体系动力学响应的有限元模拟,研究塔线体系简化模型在动态响应中的适用性。结果表明,两种模型弯曲变形误差小,低阶的振型相同,固有频率值误差小,动力特性基本相同;脱冰工况下,自立塔节点位移和塔材内力时程曲线一致,在提高计算效率的情况下,能有效保证计算精度。  相似文献   
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Abstract

This work examines the development and characterization of tripropylene glycol di-acrylate/liquid crystal E7 (TPGDA/LC E7) PDLCs composite materials (polymer-dispersed-liquid-crystals). These systems were produced by UV irradiation photopolymerization (PIPS) of a mixture of the monomer tripropylene glycol di-acrylate (TPGDA) and the liquid crystal E7 (LC E7, a mixture of three cyano-biphenyl and one cyano-terphenyl LCs), in the presence of 2?wt% (of the acrylate/E7 mixture) of a photoinitiator. Electro-optical, thermal and optical characterization was used to understand the effect of the LC concentration on the electro-optical and thermo-physical properties of these materials. Polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) studies were performed to observe the system morphology and to determine the transition temperatures of these materials, both as a function of their composition. The findings showed a slight variation of the nematic-isotropic transition temperature, TNI, of the LC E7 and of the glass transition temperature, Tg, of the TPGDA polymeric matrix as a function of the mass percentage of the LC E7. A very good electro-optical response for the composition 30/70?wt % TPGDA/LC E7 was obtained.  相似文献   
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针对大型张拉整体结构的设计问题,选取四棱柱状张拉整体结构和截角正八面体状张拉整体结构作为基本胞元,采用节点连接节点的方式建立球柱组合式数字状张拉整体结构,并使用基于结构刚度矩阵的大变形非线性数值求解方法对其进行力学性能分析.在两类胞元满足各自的自平衡条件和稳定性条件的前提下,组合得到的数字状张拉整体结构亦处于自平衡稳定状态,搭建了实物模型进行验证.以数字8状张拉整体结构为例,模拟研究了结构承受自重等分布载荷和单轴拉压等端部载荷时的静力学响应,以及结构无阻尼振动时的固有频率和模态等动力学性能.结果表明,结构在自重作用下的变形行为受初始预应力、压杆密度和拉索刚度的影响较大,对其进行合理配置方可确保结构具有足够刚度抵抗自重;结构在单轴拉压作用下呈现非线性的载荷-位移曲线,拉伸刚度随变形量的增大而增大,压缩刚度随变形量的增大而减小;结构的固有频率随初始预应力的增大而增大,而模态振型基本不变.研究结果丰富了大型张拉整体结构的外形种类,有望推动此类结构在土木建筑、结构材料等领域的应用.   相似文献   
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