Noncovalent complexation of glucosylthioureidocalix[4]arenes with carboxylates and their gas-phase characteristics: an ESI-FTICR mass spectrometric study

The noncovalent complexation of three glucosylcalix[4]arenes (1-3) towards 23 mono- and dicarboxylic acid anions were studied by ESI-FTICR mass spectrometry. Competitive complexation, collision-induced dissociation and gas-phase H/D-exchange experiments were performed to obtain information on selectivity of calixarenes towards carboxylates and characteristics of their complexes. The flexibility and number of glucose units of the host and the spatial disposition of the hydrogen bonding groups on the carboxylate guests were found to affect the selectivity of complexation strongly. The glucosylcalixarenes exhibited particular selectivity for dicarboxylic acid anions incorporating π-systems, and clear isomeric selectivity was observed for isophthalic among phthalic acid anions and for fumaric acid over maleic acid anion.     

Construction of a hyperbranched supramolecular polymer as a bifunctional antioxidative enzyme model

A HBSP has been designed as a novel bifunctional enzyme model with SOD and GPx activity by host/guest‐directed self‐assembly of MnTPyP‐M‐Ad and 6‐Te‐diCD. The structure of the host/guest complex was elucidated by ¹H NMR spectra, and the HBSP was characterized by SEM, DLS and measurement of catalytic properties. In the bifunctional enzyme model, the Mn(III) porphyrins act as efficient SOD active sites and the tellurol moieties endow GPx activity. The SOD‐like activity (IC₅₀) of this new supramolecular catalyst was found to be 1.05 × 10^?7 M, which corresponds to 2.82% of the activity of the native SOD enzyme. Besides this, the hyperbranched supramolecular polymer also shows a higher GPx activity (ν₀ = 21.7 × 10^?6 M · min^?1) than other supramolecular enzyme models.

     

Optical properties of Si0.8Ge0.2/Si multiple quantum wells

The optical property was studied on the Si_0.8Ge_0.2/Si strained multiple quantum well (MQW) structure grown using ultra-high vacuum chemical vapor deposition (UHV-CVD). Three peaks are observed in Raman spectrum, which are located at about 510, 410, and 300 cm⁻¹, corresponding to the vibration of Si–Si, Si–Ge, and Ge–Ge phonons, respectively. The photoluminescence (PL) spectrum originates from the radiative recombinations both from the Si substrate and the Si_0.8Ge_0.2/Si MQW. For Si_0.8Ge_0.2/Si strained MQW, the transition peaks related to the MQW region observed in the photocurrent (PC) spectrum were preliminarily assigned to electron–heavy hole (e–hh) and electron–light hole (e–lh) fundamental excitonic transitions.     

Bipolar Tetraarylsilanes as Universal Hosts for Blue,Green, Orange,and White Electrophosphorescence with High Efficiency and Low Efficiency Roll‐Off

A series of tetraarylsilane compounds, namely p‐BISiTPA ( 1 ), m‐BISiTPA ( 2 ), p‐OXDSiTPA ( 3 ), m‐OXDSiTPA ( 4 ), are designed and synthesized by incorporating electron‐donating arylamine and electron‐accepting benzimidazole or oxadiazole into one molecule via a silicon‐bridge linkage mode. Their thermal, photophysical and electrochemical properties can be finely tuned through the different groups and linking topologies. The para‐disposition compounds 1 and 3 display higher glass transition temperatures, slightly lower HOMO levels and triplet energies than their meta‐disposition isomers 2 and 4 , respectively. The silicon‐interrupted conjugation of the electron‐donating and electron‐accepting segments gives these materials the following advantages: i) relative high triplet energies in the range of 2.69–2.73 eV; ii) HOMO/LUMO levels of the compounds mainly depend on the electron‐donating and electron‐accepting groups, respectively; iii) bipolar transporting feature as indicated by hole‐only and electron‐only devices. These advantages make these materials ideal universal hosts for multicolor phosphorescent OLEDs. 1 and 3 have been demonstrated as universal hosts for blue, green, orange and white electrophosphorescence, exhibiting high efficiencies and low efficiency roll‐off. For example, the devices hosted by 1 achieve maximum external quantum efficiencies of 16.1% for blue, 22.7% for green, 20.5% for orange, and 19.1% for white electrophosphorescence. Furthermore, the external quantum efficiencies are still as high as 14.2% for blue, 22.4% for green, 18.9% for orange, and 17.4% for white electrophosphorescence at a high luminance of 1000 cd m^?2. The two‐color, all‐phosphor white device hosted by 3 acquires a maximum current efficiency of 51.4 cd A^?1, and a maximum power efficiency of 51.9 lm W^?1. These values are among the highest for single emitting layer white PhOLEDs reported till now.     

多总线融合式通用自动测试系统设计

为在一个测试系统上能满足更多的测试要求,避免资金浪费和重复性建设,基于PC/104主机设计了一种通用测试系统。该系统能融合多种总线,集成多种仪器,并考虑了网络化和构建大型分布式测试系统的需要,可根据实际需要灵活组配、构建自动测试系统。采用新一代IVI技术,能够较好地实现仪器的互换性,并设计了PC/104总线和MXI总线的转接口,解决了GPIB总线传输速度低的缺点,提高了测试速度。实验表明,PC/104总线和MXI总线间传输速度能达到10 MB/s以上,缩短了测试时间,且系统能够可靠稳定工作。     

视频监控系统在无人值守变电站的应用

无人值守变电站视频监控系统采用C/S体系结构,H.264压缩标准的嵌入式网络编码器提供视频服务,视频流通过2 M光纤信道,组播方式传输到主站系统,主站系统与MIS网和调度网无缝结合,从局内各工作站可以远程监控各个变电站运行情况。该系统集先进性、开放性、可靠性与实时性为一体,为实现变电站的无人值守提供了基本保障,促进了电力系统的自动化、现代化和综合性管理。     

ARM与上位机的蓝牙通信系统设计

针对某型导弹装备嵌入式数据采集系统与上位机的通信受复杂环境影响大,不稳定和布线不便的问题,采用CSR公司新一代蓝牙芯片,设计了二者之间的蓝牙通信系统。给出了蓝牙通信系统的总体实现方案,软硬件结构框图。系统由ARM与蓝牙芯片接口电路和上位机与蓝牙芯片接口电路组成。测试结果表明,二者之间的通信不再受复杂环境的影响,数据传输稳定,可靠性高,通信更为方便。     

一种便携式故障检测系统的设计

供输弹机是武器上易发生故障的子系统,以往的故障检测设备体积庞大。针对这一问题,以某型火炮的供输弹机为对象,结合数据采集的思想,提出了一种基于嵌入式PC104控制总线的便携式故障检测系统。论述了该系统的工作原理,硬件设计,并阐述了基于Visual C++开发工具的系统软件实现。试验表明,该检测系统在保证供输弹机运转的同时,能够快速检测弹丸输送中的多路信号,为准确定位供输弹机的故障,提供了有效的解决方案。     

二维聚合物分散液晶光子晶体的制备与研究

为了改善现有聚合物分散液晶(PDLC)光子晶体(PC)的制备方法和电光特性,利用532nm激光干涉条纹引发聚合物和液晶的混合物相分离,采用全息两次不等时曝光的方法,即第1次曝光完成后,将样品沿基板中心法线旋转60°进行第2次曝光,制备得到电可调谐的二维三角格子的PDLC-PC。实验结果表明,两次曝光的时间对聚合物和液晶的相分离程度影响很大,用偏光显微镜观察优化条件下制备得的二维PDLC-PC发现,聚合物和液晶在二维空间上呈规则的三角格子周期性分布。用波长为633nm的He-Ne激光器探测得到在未施加电压时不同晶格常数的PDLC-PC的衍射图样,并根据一级衍射的电光变化曲线,可以看到,其衍射效率可以利用电场进行有效的调节。