Photoinduced Tuning of Optical Stop Bands in Azopolymer Based Inverse Opal Photonic Crystals

Photo‐tunable photonic crystals were prepared from three dimensional (3D) colloidal crystal templates using a photoresponsive azopolymer. For the preparation of azopolymer infiltrated photonic crystals, silica colloidal crystals were fabricated by gravity sedimentation, a self‐assembly technique. The interstitial voids between colloidal particles were filled with azopolymer and azopolymer inverse opals were produced by treatment with aqueous hydrofluoric acid. These photonic crystals exhibited stop bands in their transmission spectra measured in the normal incidence to the (111) plane of face centered cubic (fcc). The photonic bandgap of the azopolymer infiltrated opal and inverse opal could be controlled by the refractive index change due to the photoinduced orientation of azobenzene chromophores. When the azopolymer photonic crystals were irradiated with linearly polarized light, their bandgap positions were shifted to shorter wavelength regions with increasing irradiation time. This behavior experimentally produced a photoinduced orientation of the azobenzene groups in parallel with the incidence of the excitation light. Through such an out‐of‐plane orientation of azo chromophores, parallel to the [111] fcc crystallographic axis, the effective refractive index of the photonic crystal medium was decreased. Therefore, a blue‐shift in bandgap positions was consequently induced with 20–40 nm tuning ranges. The out‐of‐plane orientation was confirmed by angular resolved absorption spectral measurements.     

Increasing the Efficiency of Organic Dye‐Sensitized Solar Cells over 10.3% Using Locally Ordered Inverse Opal Nanostructures in the Photoelectrode

3D inverse opal (3D‐IO) oxides are very appealing nanostructures to be integrated into the photoelectrodes of dye‐sensitized solar cells (DSSCs). Due to their periodic interconnected pore network with a high pore volume fraction, they facilitate electrolyte infiltration and enhance light scattering. Nonetheless, preparing 3D‐IO structures directly on nonflat DSSC electrodes is challenging. Herein, 3D‐IO TiO₂ structures are prepared by templating with self‐assembled polymethyl methacrylate spheres on glass substrates, impregnation with a mixed TiO₂:SiO₂ precursor and calcination. The specific surface increases from 20.9 to 30.7 m² g^?1 after SiO₂ removal via etching, which leads to the formation of mesopores. The obtained nanostructures are scraped from the substrate, processed as a paste, and deposited on photoelectrodes containing a mesoporous TiO₂ layer. This procedure maintains locally the 3D‐IO order. When sensitized with the novel benzothiadiazole dye YKP‐88, DSSCs containing the modified photoelectrodes exhibit an efficiency of 10.35% versus 9.26% for the same devices with conventional photoelectrodes. Similarly, using the ruthenium dye N719 as sensitizer an efficiency increase from 5.31% to 6.23% is obtained. These improvements originate mainly from an increase in the photocurrent density, which is attributed to an enhanced dye loading obtained with the mesoporous 3D‐IO structures due to SiO₂ removal.     

Electrowetting‐Induced Morphological Evolution of Metal‐Organic Inverse Opals toward a Water‐Lithography Approach

This paper presents a unique morphological evolution of metal‐organic inverse opals (Pb(NO₃)₂‐poly(St‐MMA‐AA)) subjected to an electrowetting process. The morphology of the building blocks changes from interconnected pores to separated hollow spheres during the electrowetting process, accompanied by an unusual blue‐shift of the stopband position and the decreased wettability of the film. This morphology evolution is attributed to the simultaneous collapse/reconstruction of the metal‐organic frame owing to the partial dissolution of the metal salt and the interfacial assembly of the metal‐organic coordination around the skeleton. The adjustable morphology can be developed as a novel and simple water‐lithography approach for the creation of the photonic crystal pattern.     

NaF对BMT系陶瓷结构及介电性能的影响

Ba(Mg1/3Ta2/3)O3(BMT) 具有复合钙钛矿型结构。其微波性能优异(Q > 12 000),但由于烧结温度很高(1 5301 650℃),导致成本增加,难以实用化。本实验中采用传统的固相法制备纯的BMT,然后以NaF作为添加剂,研究了NaF对BMT结构和介电性能的影响,结果表明以NaF为添加剂可大幅度降低烧结温度。样品在1 350 ℃烧结时,具有良好的介电性能。     

MnCO3对BMT系陶瓷结构和微波特性的影响

研究了w(MnCO3)从0．5％～5％(质量分数)对复合钙钛矿Ba(Mg1／3Ta2/3)O3(BMT)系陶瓷结构和微波特性的影响。对于w(MnCO3)为0．5％的BMT系陶瓷,其主晶相为1：2有序六方超晶格和无序立方结构,相应于最大的品质因数与频率的积(Qf)值。随着w(MnCO3)的增加,其Qf值下降。介电常数ε随w(MnCO3)的增大而略有下降,这是由于附加相Ba0.5TaO3影响所致。     

Magnetic Force Microscopy Images of a Nanometer‐Sized,Purely Organic High‐Spin Polyradical

Magnetic force microscopy (MFM) was applied to study both the molecular image and the magnetic response of π‐conjugated, non‐Kekulé‐, and nondisjoint‐type poly(1,2‐phenylenevinylene) (nondisjoint refers to a molecule in which non‐bonding molecular orbitals share the same region in the molecule and a multiplet ground state is significantly stabilized) networks bearing 4‐substituted di‐tert‐butylphenoxyl moities. The polyphenoxyl radicals 1 with molecular weights of 2.6, 9.3, and 32 kDa have a substantial stability even at room temperature and in air, and molecular sizes in the nanometer range of 10, 20, and 35 nm, respectively, with a disk‐like shape. The MFM clearly shows a magnetic gradient response exactly on the position of the polyradical molecule dispersed on a graphite surface. The MFM molecular image of polyradical samples with different molecular weights and spin concentrations was examined as a nanoscale and single‐molecular‐based magnetic dot.     

矩阵摄动理论在二维有耗介质柱局部逆散射中的应用

本文提出二维有耗介质柱局部逆散射的矩阵摄动理论。作为生物体的简单模型，当二维有耗介质柱内部结构发生局部变化时，其散射电磁场随之改变。本文根据矩阵摄动理论导出了变化的散射场与介电常数，电导率之间的简明关系，并得到逆问题的各阶摄动解。     

Liquid-Phase Super Photoactuator through the Synergetic Effects of a Janus Structure and Solvent/Thermal/Photo Responses

Azobenzene actuator has attracted wide research attention in the fields of soft robots, artificial muscles, etc., owing to the typical photoresponsive material based on its reversible trans–cis isomerization. However, it remains challenging to enhance the actuation performance of azobenzene actuators through simple methods and can work in complex and variable environments. In contrast to complex molecular functional design, this study presents a Janus azobenzene inverse opal actuator: one side of a monodomain azobenzene polymer and the other side of a polydomain azobenzene inverse opal structure. The proposed design can significantly enhance the photoactuation performance in the liquid phase based on the synergetic effects of the Janus structure and the plastic influence of solvent/thermal/photo responses on the polymer segment. Promising applications of photo-driven ring rolling in the liquid phase are demonstrated. The results of this study are of great significance for the design and fabrication of novel-type azobenzene actuators in the liquid phase.     

95陶瓷散热基片生产中若干质量问题

介绍了95陶瓷散热基片生产过程中应控制的几个质量问题，重点分析了95瓷的配料，烧结及其基板金属化的附着力等。     

磁镜场在直接耦合式微波等离子体化学气相沉积金刚石膜制备装置中的应用

在直接耦合式微波等离子体化学气相沉积金刚石膜装置的石英管反应腔加上磁镜场来更好地约束等离子体,使等离子体球成为“碟盘”状,提高了等离子体球的密度,在基本参数：反应压力2．5kPa、基片温度450℃、气体流量为Ar：40sccm、CH4：4sccm、Hz：60sccm不变的情况下,沉积面积直径由30mm增长到50mm,沉积速度由3．3μm／h增长到3．8μm／h,最大反射电流由15μA减小5μA。从而大大减少了在石英管壁和观察窗的沉积,有效利用微波能量电离出更多的活性基团沉积出高质量的（类）金刚石薄膜。     

软磁非晶丝巨磁阻抗效应传感器研究进展与应用

基于软磁非晶丝巨磁阻抗效应(GMI)的传感器是近年来磁传感器领域的研究热点之一.非晶丝具有良好的软磁特性:如低电阻率、高磁导率、高饱和磁感应强度、低矫顽力、低损耗以及特殊的磁畴结构等,利用其GMI效应制成磁传感器,其突出优点是微型化、高灵敏度、快速响应、高温度稳定性和低功耗.本文讨论了软磁非晶丝巨磁阻抗效应的机理,叙述了非晶丝GMI传感器的研究进展,着重对敏感材料性能及制备、GMI器件结构形式、传感电路等作了介绍,并指出了GMI目前存在的问题及将来的发展趋势.最后对GMI的应用作了展望.     

磁卡机用于测量收费系统的研究

在分析磁卡记录特征和磁卡读写器控制信号及其时序的基础上提出由智能测最仪器以串行通信方式控制磁卡机的读写操作方案并给出了智能测量仪器与磁卡机通信控制的硬件连接和软件流程.     

国家级弱磁实验室高精度中央空调设计

弱磁计量实验室对磁环境、温度控制精度均有严格要求.普通恒温恒湿空调器虽然能达到温度控制精度要求,但由于含铁磁物质,不能在该环境下使用;常规中央空调系统虽然可以满足磁环境要求,但难以满足温度波动小于0.2℃/h的温控精度要求.本项目设计采用中央空调加分区控温的方式较好地解决了该难题,设计中采用高效能热隔离、小温差送风、孔...     

电厂及工业控制计算机监视器磁场干扰的抑制

本文对生产现场磁场干扰的产生及其对计算机监视器的危害作了简要分析。并给出实测结果。提出了计算机监示器免受磁场干扰的各项措施。     

TWT周期磁场分解合成软件的研制与应用

本文介绍TWT周期磁场分布到单环值的分解合成软件的研制和初步的应用。     

Magnetic Responsive On-Site Switching of the Directional Droplet Self-Transport in Shape Memory Slippery Tube

The phenomenon of controlled droplet transport has promising application prospects in various fields. Active droplet transport mode is controllable through continuous external stimuli. By contrast, self-transport is a more environmentally friendly and energy-efficient passive transport mode but lacks controllability. In this study, controlled self-transport is achieved by constructing a shape memory polymer (SMP) tube with a lubricated magnetic-responsive gel inner surface. The asymmetrical shape of the tube, combined with the lubricated inner surface, enables directional self-transport of droplets without external stimuli. Furthermore, the resistance on the inner gel surface can be altered by regulating the magnetic field to achieve effective active control during the self-transport process. Thus, smart in situ control of droplet transport can be achieved by integrating the macroscale shape variation of the tube with the dynamic control of the inner surface microstructure. Owing to the fast magnetic responsivity and in situ controllability of the self-transport process, the SMP lubricated tube demonstrates the ability to transport a variety of liquids and can be designed as a micro-reactor for step-by-step droplet detection. The findings of this study may provide guidance for the development of intelligent interface materials and microfluidic devices.     

Orientation of Organic Nanocrystals Grown in Sol–Gel Matrices under a High Magnetic Field

In order to obtain new optical properties, such as quadratic nonlinear optical or electro‐optical properties, we have undertaken the orientation control of organic nanocrystals during their growth in the pore of sol–gel matrices by applying a high magnetic field, H , of 16 T. H favors the dye aggregation and improves the crystalline quality of nanocrystals by reducing the orientation freedom of molecules and clusters through their diamagnetic susceptibility. When H is not applied, the NPP (N‐(4‐nitrophenyl)‐(L )‐prolinol) nanocrystals generate a weak second harmonic generation (SHG) intensity due to self‐oriented domains of nanocrystals induced by dipole–dipole interactions. In the case of 3‐methyl‐4‐nitropyridine‐1‐oxide (POM), which exhibits a very weak dipolar moment, no SHG signal can be detected. When H is applied, the SHG intensity of NPP nanocrystals increases significantly due to the reduction of their orientational freedom and the increase of dipole–dipole interactions, thus improving the formation of oriented domains of nanocrystals.