Mass spectrometric study of six cyclic esters

A series of cyclic esters, which are optically active as a consequence of their helical structures, were synthesized to investigate the relationships between their structures and their optical activities. This paper reports the electron impact fragmentation mechanisms of these six cyclic esters. Accurate mass measurements and mass analyzed ion kinetic energy spectrometry confirmed fragmentation patterns. The stability of the fragment ions has a great influence on the fragmentation pathways, but no correlation with the optical activity was found.     

Synthesis of New Spiropyrans With a Polyaromatic or Heteroaromatic Pendant and Their Photochromic Bedhaviors

A series of spiropyrans with a polyaromatic or heteroaromatic pendant was synthesized conveniently.Their photochromic behaviors were investigated with the aid of absorption spectral measurements.The results indicated that the compounds with the same parent spiropyran but different aromatic pendant show significantly different photochromic properties.This may be due to the π-π orbital interaction between the polyaromatic pendant and the open photomerocyanine form of spiropyran.The results obtained are very useful in the molecule design area.     

Diaquabis(2,5‐dihydroxybenzoato‐κO)bis(1,10‐phenanthroline‐κ2N,N′)strontium(II) bis(1,10‐phenanthroline) tetrahydrate

The title compound, [Sr(C₇H₅O₄)₂(C₁₂H₈N₂)₂(H₂O)₂]·2C₁₂H₈N₂·4H₂O, consists of an Sr^II complex, uncoordinated phenanthroline (phen) molecules and solvent water molecules. The Sr^II ion is located on a twofold axis and is coordinated by two phen ligands, two dihydroxybenzoate anions and two water molecules in a distorted tetragonal antiprismatic geometry. Partially overlapped arrangements exist between parallel coordinated and parallel uncoordinated phen rings; the face‐to‐face separations between the former (coordinated) and the latter (uncoordinated) rings are 3.436 (13) and 3.550 (14) Å, respectively. This difference suggests the effect of metal coordination on π–π stacking between phen rings.     

Mn0.6Zn0.4Fe2O4/α-Fe2O3复合材料的磁性和电阻率温度关系研究

采用化学共沉淀法制备了Mn0.6Zn0.4Fe2O4和α-Fe2O3纳米微粉,进而利用陶瓷工艺制备了(Mn0.6Zn0.4Fe2O4)1-x/(α-Fe2O3)x纳米晶复合块体材料.详细研究了(Mn0.6Zn0.4Fe2O4)1-x/(α-Fe2O3)x样品的相结构、磁学性质和电阻率的温度依赖性.研究发现在Mn0.6Zn0.4Fe2O4中掺入适量的α-Fe2O3可改善材料的高频软磁性能,也可改善样品电阻率的温度灵敏度.从而为锰锌铁氧体性能的改善提供了新的线索.     

N-terminal of L protein of vesicular stomatitis virus contains a new signal sequence

The L protein (241kD) of vesicular stomatitis virus (VSV) is the most important snbnnit of the replication complex. The existence of specific localization signal in the L protein was investigated by making recombinant constructs expressing truncated mutants of the L protein fused to green fluorescent protein (GFP) in transient transfection assays. The chimeric genes encoding varied N-terminal of L and GFP gene were put under the control of T7 promoter or CMV promoter. The fusion proteins were transiently expressed in BHK-21, COS-7, CHO or Hep G2 cells. When more than 120 residues were deleted or only 96 residues were kept on the N-terminal, the fusion proteins were shown to be distributed throughout the cells, cytoplasm and nucleus under the confocal microscope. However, other chimeric proteins with 120 or more amino acids were dotted and distributed in the perinuclear regions. And the fusion protein with 96—120 aa has the similar distribution. A thirteen-residue peptide QGYSFLHEVDKEA (108—120) was identified as localization signal, whose function would be absolutely distributed with the deficiency of D or V. Our results show that there is an independent localizing signal in N-terminal domain of L protein of VSV and this functional signal is conserved in different cell lines.     

高师声乐钢琴伴奏初探

钢琴伴奏是一门音乐表演艺术，在声乐伴奏中，它是配合歌唱成功的完成声乐作品的关键，本文分析、阐述、说明了钢琴伴奏在声乐演唱中的重要作用。     

网络信息安全特种保障初探

提出了特种保障的概念，分析了国家信息安全的危害因素，主要有CPU隐含指令，后门，恶意硬件等。通过研究非自主开发的计算机系统中的系统恶意功能集和触发条件以可以发现恶意功能的协议数据序列，给出了两种恶意功能的检测方法，即激励响应检测法和特征匹配检测法。据此给出了有关网络恶意功能的防治措施。     

一种改进的离线电子现金方案

在分析Brands的受限盲签名方案的基础上提出了一个改进的电子现金支付新方案，基于此构建了一个不带“观察器”的简约高效电子现金方案，详细描述了离线电子现金支付方案作提取、支付和存储三个协议．分析了新方案的效率和安全性，与Brands的电子现金协议相比，在不降低安全他的前提下提高了处理效率、增加了灵活性，尤其适用于因持网上的小额支付．     

催化杀虫剂西维因水解的抗体酶制备(Ⅰ)抗原的分子设计、合成与优选

以杀虫剂西维因酯解反应中间过渡态的结构信息进行分子设计，合成了α－萘基磷酸氢酯半抗原，将其与载体蛋白牛血清白蛋白（ＢＳＡ）和鸡卵清蛋白（ＣＥＡ）偶联，制得了具有不同抗原价（４～２２）的合成抗原．经小鼠免疫学实验，优选出了可产生滴度高、特异性强之抗血清的免疫用抗原（Ｈａｐ－ＢＳＡ）．经酶联免疫吸附试验（ＥＬＩＳＡ）测定，用该免疫原制得的鼠抗血清滴度可达１∶３２０００．优选抗原Ｈａｐ－ＢＳＡ可被用作产生催化西维因水解之抗体酶的免疫原．     

主理想整环上的线性方程组

对主理想整环上的线性方程组作了初步探讨，推广了域上线性方程组的已知结果，并给出求解的几种新方法。