八肋游仆虫Rab家族新成员Eo-rab-1 N基因的克隆与序列分析

Rab蛋白家族属于小分子GTP结合蛋白家族Ras超家族中最大的亚家族,主要在囊泡运输中起作用。实验运用PCR、RT-PCR等技术,从八肋游仆虫中克隆到一种新的rab基因。序列分析结果表明:在大核中,该基因全长884 bp,除去两端的端粒与非编码区,该基因在大核中由723 bp组成。从小核中克隆相应的基因片段,此基因片段序列与大核中序列一致,表明该基因在小核中无内部删除序列的存在。通过RT-PCR,从mRNA获得的该基因的开放读框为663 bp,表明该基因在转录过程中有内含子的删除。大核基因序列和cDNA序

Molecular weight dependence of phase Behavior of PEO/P(EO-b-DMS) blends: Application of Sanchez-Lacombe lattice fluid theory

Molecular weight dependence of phase separation behavior of the Poly (ethylene oxide) (PEO)/Poly(ethylene oxide-block-dimethylsiloxane) (P(EO-b-DMS)) blends was investigated by both experimental and theoretical methods. The cloud point curves of PEO/P(EO-b-DMS) blends were obtained by turbidity method. Based on Sanchez-Lacombe lattice fluid theory (SLLFT), the adjustable parameter, epsilon*(12)/k (quantifying the interaction energy between different components), was evaluated by fitting the experimental data in phase diagrams. To calculate the spinodals, binodals, and the volume changes of mixing for these blends, three modified combining rules of the scaling parameters for the block copolymer were introduced.

Abnormal pressure dependence of the phase boundaries in TL/PEO/P(EO-b-DMS) ternary mixtures

The cloud-point temperatures (T-cl's) of both binary poly(ethylene oxide) (PEO)-poly(ethylene oxide-b-dimethylsiloxane) [P(EO-b-DMS)] and ternary[toluene/PEO/P(EO-b-DMS)] systems were determined by light scattering measurements at atmospheric pressure. The phase separation behavior upon cooling in the ternary system has been investigated at atmospheric pressure and under high pressure and compared to the phase behavior in the binary system. The phase transition temperatures have been obtained for all of the samples. As a result, the pressure induces compatibility in the binary mixtures, but for the ternary system, pressure not only can induce mixing but also can induce phase separation.

Thermodynamics of phase behavior in PEO/P(EO-b-DMS) homopolymer and block co-oligomer mixtures under pressure

The cloud-point temperatures (T-cl's) of poly(ethylene oxide) (PEO) and poly(ethylene oxide)-block-polydimethylsiloxane (P(EO-b-DMS)) homopolymer and block-oligomer mixtures were determined by turbidity measurements over a range of temperatures (105 to 130degrees), pressures (1 to 800 bar), and compositions (10-40 wt.-% PEO). The system phase separates upon cooling and T-cl was found to decrease with an increase in pressure for a constant composition. In the absence of special effects, this finding indicates negative excess volumes. Special attention was paid to the demixing temperatures as a function of the pressure for the different polymer mixtures and the plots in the T-phi plane (where phi signifies volume fractions). The cloud-point curves of the polymer mixture under pressures were observed for different compositions. The Sanchez-Lacombe (SL) lattice fluid theory was used to calculate the spinodals, the binodals, the Flory-Huggins (FH) interaction parameter, the enthalphy of mixing, and the volume changes of mixing. The calculated results show that modified P(EO-b-DMS) scaling parameters with the new combining rules can describe the thermodynamics of the PEO/P(EO-b-DMS) system well with the SL theory.

添加剂对EO/THF共聚醚聚氨酯热氧降解的影响

采用FT-IR及NMR技术研究固化催化剂、增塑剂、抗氧剂及聚醚二元醇结构对聚醚聚氨酯热氧降解过程的影响． 增塑剂邻苯二甲酸二丁酯(DBP)在聚醚聚氨酯热氧降解过程中起阻降作用． 而固化催化剂二月桂酸二丁基锡(DBTDL)和三苯基铋(TPB)对聚醚聚氨酯的热氧降解有着截然不同的影响． 以聚乙二醇(PEG)为聚醚二元醇的聚醚聚氨酯与环氧乙烷/四氢呋喃(EO/THF)共聚醚聚氨酯具有相似的降解机理；DBP增塑时PEG聚醚聚氨酯比共聚醚聚氨酯具有较低的热氧稳定性，而硝酸酯增塑时PEG体系比共聚醚体系表现出较高的热氧稳定性.

Studies of catalyzed reaction mechanism between co-polyether (THF/EO) and N-100 by NMR - Interaction and complex formation between reactants and catalysts

To elucidate the mechanism of the catalyzed reaction of co-polyether (EO/THF) with N-100, the interaction and complex formation between reactants and catalysts were investigated by means of NMR spectroscopy. It is shown that the resonance peak of isocyanate carbon splits into two parts when the solutions of N-100 and co-polyether were mixed. The disappearing of proton resonance peak of hydroxyl group in NMR spectra when dibutyltin dilaurate(DBTDL) were added to the copolyether(THF/EO) solution indicates the complex formation, This interaction appears to be a bonding of tin to the oxygen of hydroxyl and make the hydrogen of the hydroxyl group very mobile and active, then exchange with other protons, In the case of triphenyl bismuth(TPB), the high field shift and intensity enhancement of proton peak were observed, which suggest a nucleophilic attack of the bismuth to the hydroxyl hydrogen.

STUDIES ON STRUCTURE OF EO/THF RANDOM COPOLYETHER(I) - NMR-STUDIES ON SOLUTION ACTION AND COMPLEX

The special action of TEO solution was investigated by 1D, 2D-NMR in CDCl3. For the present measurements, when the concentration of TEO was higher in CDCl3, the chemical shift difference (Delta delta) and the peak number of C-13 NMR spectrum were changed with increasing the solution concentration, At lower concentration(< 3% V/V ), the peaks will be closed together for -CH2O- resonance carbon and it is not the appearance of the narrowed, When temperature was changed, the Delta delta value was contrary to the solvent effect, So, the shifts of the resonance carbon in the NMR spectra indicated clearly that the complex formation for the system of CDCl3, and TEO molecular interaction were affected by the experiment temperature and the solution concentration.

EO／THF无规共聚醚结构研究（Ⅱ）──NMR方法研究溶剂配合物与溶液行为

用１Ｄ－ＮＭＲ和２Ｄ－ＮＭＲ方法研究了ＥＯ／ＴＨＦ共聚醚（ＴＥＯ）的溶液行为。ＴＥＯ在浓溶液状态，其溶液浓度不仅使谱峰化学位移值增减，而且使峰型发生较大的变化。当改变温度时，~（１３）ＣＮＭＲ谱在高场区有如同溶剂化效应的过程，实验结果表明：浓度与温度使ＴＥＯ溶液分子内部结构发生变化。２Ｄ－ＮＯＥＳＹ实验表明：在低浓度情况下，ＴＥＯ分子易与活泼氢溶剂生成配合物，分子间偶极－偶极相互作用受温度和浓度的影响。

EO／THF无规共聚醚结构研究（Ⅰ）──端羟基液体共聚醚的NMR分析

用核磁共振技术研究了环氧乙烷（ＥＯ）与四氢呋喃（ＴＨＦ）端羟基液体共聚醚（ＴＥＯ）的链结构，定量测定了ＴＥＯ的结构组成参数以及二元组与三元组序列分布。实验结果表明，端羟基液体ＴＥＯ易形成以Ｅ－ＯＨ为端基的线型无规交替结构，且序列分布随ＥＯ／ＴＨＦ组成比而变化。

三元共聚物P(EO-PO-AGE)-LiCLO_4络合物的离子电导

本文合成了聚(环氧乙烷-环氧丙烷-烯丙基缩水甘油醚,三元共聚物,P(EO-PO-AGE)。扭辨分析、DSC、X-射线衍射结果表明,三元共聚物的玻璃化转变温度较低(T_g=-74℃),无定形结构含量～98％,并确定了与LiClO_4组成为Li/O(mole)=0.25的结晶络合物存在。络合物电导行为的研究发现,络合物电导与盐浓度有关,在Li/O(mole)=0.05时具有较大值,室温下电导可达5×10~-5)scm~(-1)。

二甲氧基聚乙二醇增塑的P(EO-PO-AGE)-LiClO_4聚合物膜的离子电导

本文研究了二甲氧基聚乙二醇(PEGDME)对聚合物电解质膜的影响。结果表明,PEGDME增塑的(环氧乙烷-环氧丙烷-烯丙基缩水甘油醚)三元共聚物-LiClO_4络合物具有较低的玻璃化转变温度,室温导电率≥10~(-4)Scm~(-1),热稳定性及力学性能良好,在100℃下无相分离,室温下在干燥器中放置一年无蠕变。

Polarization analysis and experimental implementation of PLZT electro-optical switch using fiber Sagnac interferometers

The polarization characteristics of electro-optical (EO) switches using fiber Sagnac interferometer (FSI) structures are theoretically investigated. Analytical solutions of output fields are presented when the twists and birefringence in a Sagnac loop are considered. Numerical calculations show that the twists of fiber, the orientation of the inserted phase retarder, and the splitting ratio of the coupler will influence both the output intensity and the output polarization properties of the proposed switch. A polarization-independent EO switch based on a Sagnac interferometer and a PUT bar was experimentally implemented, which showed good coincidence with the analytical results. The experiment showed a switch with 22 dB extinction ratio and less than 31.1 ns switching time. (c) 2006 Optical Society of America.

基于PLZT的电光偏转器的特性研究

采用具有高二次电光效应的掺镧锆钛酸铅陶瓷材料（PLZT），设计和制备了一种基于折射率随外加电压发生变化的电光偏转器。构建了测试系统，测得PLZT的电光系数是R33=2.1