A hyperbranched,rotaxane‐type mechanically interlocked polymer

Based on the dibenzo‐24‐crown‐8/1,2‐bis(pyridinium)ethane recognition motif, a hyperbranched mechanically interlocked polymer was prepared by polyesterification of an easily available dynamic trifunctional AB₂ pseudorotaxane monomer. It was characterized by various techniques including ¹H NMR, COSY, NOESY, GPC, viscosity, TGA, dynamic laser light scattering, AFM, and SEM. Its GPC M_n was determined to be 191 kDa with polydispersity 1.7 and its hydrodynamic diameter in a dilute solution in acetone was about 70 nm. This measured M_n value corresponds to about 93 repeating units. The study reported here presents not only a new polymer topology but also a novel and convenient way to prepare mechanically interlocked polymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4067–4073, 2010     

移动虚拟专用网业务

介绍在数字移动通信中虚拟专用网技术的业务特点，实现及原理及发展前景。     

WAPP2.0 PUSH技术在无线网络中的应用

WAP（无线应用协议）是一个开放的工业标准，代表了未来网络中移动通信网和因特网相结合的发展方向。本文分析了其最新版本WAP2.0协议的新特性及其“推”（PUSH）技术构架，并探讨了它在无线网络中的应用实现。     

Au/ZnO/TiO_2复合薄膜的制备及光电转换性质

以含有Au和ZnO纳米颗粒的氢氧化钛溶胶作为成膜液,通过浸渍-提拉及灼烧处理在导电玻璃表面制备Au/ZnO/TiO2复合薄膜.利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)等方法对所得产物进行表征.结果表明,Au和ZnO纳米颗粒均匀地分布在多孔TiO2薄膜上,通过TiO2、ZnO和Au三组分的协同效应促进了光吸收和电荷分离,使Au/ZnO/TiO2复合薄膜具有较好的光电转换性质,可用作太阳能电池材料.     

Self-catalytic synthesis of hydrophilic polypyrrole/tellurium nanocomposite and its capacitance performance

Journal of Solid State Electrochemistry - A hydrophilic polypyrrole/tellurium (PPy/Te) nanocomposite was synthesized by a facile approach in which H2TeO3 was used as the oxidizing agent of pyrrole...     

利用基于扫描相机的荧光寿命成像显微技术研究细胞周期

利用基于扫描相机的荧光寿命成像显微系统,以细胞周期为模型,研究转染绿色荧光蛋白的HeLa细胞的荧光寿命。结果表明,处于周期内不同进程的细胞的荧光寿命为2.50~3.00 ns。处于分裂期的细胞的荧光寿命在1 h内从2.86 ns下降到2.82 ns;在DNA合成前期的8 h内,荧光寿命从2.82 ns下降到2.78 ns。荧光寿命的差异反映了细胞周期中核浆内大分子浓度的变化,对了解细胞周期的分子机制有一定的意义。     

Supramolecular polymer nanofibers via electrospinning of a heteroditopic monomer

Driven by the benzo-21-crown-7/secondary ammonium salt recognition motif, a linear supramolecular polymer was formed from self-organization of a low-molecular-weight self-complementary monomer in chloroform. From this supramolecular polymer, nanofibers were obtained successfully via electrospinning.     

The study of a single BGC823 cell using Fourier transform infrared microspectroscopic imaging

In order to investigate gastric cancer at cellular and sub-cellular level, a single human gastric adenocarcinoma BGC823 cell was studied by an infrared microscope equipped with a focal plane array (FPA) detector. The spectra showed difference between the nucleus and the endoplasmic reticulum (ER) of the BGC823 cell. The peak of vasPO2- was shifted to a higher wavenumber at the nucleus compared with that at the ER. The height ratios of 2954 cm(-1)/2922 cm(-1) (CH3/CH2) and 1088 cm(-1)/1539 cm(-1) (DNA/amide II) of the nucleus were significantly higher than those of the ER. Furthermore, chemical images reveal the intensity distributions of lipids, proteins and DNA of the single BGC823 cell, and the intense absorptions of proteins and DNA were observed in the nuclear region of the cell while the intense absorption of lipids was found in the ER region of the cell. The Fourier transform infrared (FTIR) microspectroscopic imaging result indicates the study of the single gastric cancer cell at sub-cellular level can be beneficial for knowing gastric cancer more which will be of great importance for the study and diagnosis of gastric cancer. The result also suggests that FPA is a useful tool in the study of a single cell and may be a powerful tool for study and diagnosis of gastric cancer.     

A method for calibrating the position error of phase retrieval with transverse translation diversity in optical wavefront measurement

We present a method for calibrating the position error of phase retrieval with transverse translation diversity in optical wavefront in situation where the position error sharply influences algorithm precision. This method involves testifying that the essence of the position error in phase retrieval is the translation in frequency domain and the minimum of iterative error against position error reaches when there is no position error. Then the least square method is used for fitting the relationship between the iterative error and the assumed position error in polynomial function. The computer simulations used to prove the validity of this method are described. The results indicated that this method can calibrate the position error to approximately 1/500 mm which nearly has no influence on the phase retrieval.     

ATM交换的优先控制方式

本文对采用ATM体制的宽带综合业务数字网业务流的优先控制进行了研究，提出了两种新的优先控制方法。