Adsorption Behavior of a Water-soluble Porphyrin at the Glass-water Interface as Studied by Synchronous Total Internal Reflection Fluorescence Spectroscopy

Total imernal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl)porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS^4-) and diprotonated (H2TPPS^2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.     

Ibuprofen induced drug loaded polymeric micelles

Three model drugs with different function groups were chosen to dialyze with dextran-graft-poly(N-isopropylacrylamide).Only ibuprofen could induce the formation of drug loaded micelles,which was confirmed with dynamic light scattering and transmission electron microscope.Hydrogen-bonding between the amide groups of poly(N-isopropylacrylamide) and the carboxyl groups of ibuprofen was driving force for the drug-loaded micelle.It was also found that the diameter of the ibuprofen-loaded micelles changed reversibly against temperature.     

Flame retarded polymer nanocomposites: Development,trend and future perspective

Polymer nanocomposites are a new class of flame retarded materials which have attracted much attention and considered as a revolutionary new flame retardant approach.A very small amount of nano flame retardants (normally < 5 wt%) can significantly reduce the heat release rate (HRR) and smoke emission (SEA) during the combustion of polymer materials.Moreover,the addition of nano flame retardants can also improve the mechanical properties of polymer materials compared with the deterioration of traditional fla...     

不对称二亚胺异双核钴镍催化剂的合成及乙烯聚合研究

合成了不对称异双核钴镍催化剂MN5CoNi.该催化剂经AlEt3,MMAO,AlEt3/[PhMe2NH][B(C6F5)4](B)或MMAO/B活化后用于乙烯聚合.异双核催化剂与相应的等摩尔双组分混合单核催化剂相比,以TEA作助催化剂时,异双核催化剂的Co和Ni中心的活性都远低于双组分混合体系,且Ni中心生成的聚乙烯含量低于双组分混合体系,异双核催化剂中的Co和Ni中心同时被抑制.以MMAO作助催化剂时,异双核催化剂的活性虽低于双组分混合体系,但是异双核催化剂中的两种金属中心的活性都有了较大的提高,且Ni中心生成的聚乙烯含量高于后者.同时考察了活性随时间变化,发现异双核催化剂中活性衰减比双组分混合体系慢,说明异双核体系中Co和Ni中心在MMAO活化下比双组分混合体系的金属中心更稳定.当以TEA/B作助催化剂时,异双核催化剂中Co和Ni中心的活性有所提高,但仍远低于双组分混合体系,且Ni中心生成的聚乙烯含量低于后者,说明Ni被选择性抑制.当使用MMAO/B作助催化剂时,结果与MMAO类似.     

5种重要农艺性状基因在水稻重组自交系群体中的定位

通过抗病虫害水稻品系“B5”与籼稻品种“明恢63”为亲本进行杂交，得到一个187个F8代的重组自交系群体。利用重组自交系群体构建的分子连锁图，对水稻抽穗期、株高、穗长、剑叶长和剑叶宽的性状进行了QTL分析，分别检测到影响抽穗期、株高、穗长、剑叶长和剑叶宽的农艺性状2、2、4、4、4个QTLs，并分别解释各表型性状总变异的50．6％、74．9％、34．1％、47．3％和46．2‰．其中，控制抽穗期的Hd-6基因，控制株高的Ph7基因和控制剑叶长的Fll-2b基因分别是效应值较大的主效座位，其余的为微效基因座位。相关性状的QTLs大多聚集在染色体的相近或相同区间，表现出成簇分布的现象。这些重要农艺性状的分析，可以为水稻分子标记辅助选择育种提供有用的遗传信息。     

有机掺杂溶胶-凝胶法制备pH敏感膜及其光谱响应的研究

使用四甲氧基硅烷（TMOS）和二甲基二甲氧基硅烷（DiMe-DMOS)为共先驱体，采用溶胶－凝胶的有机掺杂，制备对pH具有宽程响应的敏感膜。详细考察了包埋溴酚蓝和溴酚绿的敏感膜对pH的响应值、响应时间、泄漏和可逆性等响应性能指标，并进行了溴酚蓝和溴酚绿在水相与膜内吸收光谱的研究。     

Solution-grown aligned crystals of diketopyrrolopyrroles(DPP)-based small molecules:Rough surfaces and relatively low charge mobility

Field-effect transistors(FETs) of three diketopyrrolopyrroles(DPP)-based small molecules, 3,6-bis(5-phenylthiophene-2-yl)-2,5-bis(2-ethylhexyl)pyrrolopyrrole-1,4-dione(PDPPP), 3,6-bis(5-(4-fluorophenyl)thiophene-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo pyrrole-1,4-dione(FPDPPPF) and 3,6-bis(5-(4-n-butylphenyl)thiophene-2-yl)-2,5-bis(2-ethylhexyl)pyrrolo pyrrole-1,4-dione(Bu PDPPPBu), have been studied in this work. Well aligned crystals of the three molecules were grown from para-xylene by droplet-pinned crystallization method. FETs based on these aligned crystals exhibit a hole mobility up to0.19 cm~2 V 1s 1and electron mobility up to 0.008 cm~2 V 1s 1. The achieved hole mobility is of the same order of magnitude as reported highest hole mobility for DPP-based small molecules, but it is much lower than that of the high-performance DPP-based polymers. The relative low mobility is mainly attributed to the rough crystal surfaces with steps and, thus, non-smooth charge transport channels at the interfaces between the crystals and the dielectrics. This work has implications for understanding the low charge mobility of DPP-based small molecules.     

Differential pulse voltammetric studies on the effects of Al（Ⅲ） on the lactate dehydrogenase activity

In this paper, differential pulse voltammetry (DPV) was applied to study the effects of aluminum Al(Ⅲ) on the lactate dehydrogenase (LDH) activity. Michaelis–Menten constant (KmN ADH) and maximum velocity (vmax) in the enzyme promoting catalytic reaction of "pyruvate(Pyr) NADH H LDDHlactate NAD " under different conditions by monitoring DPV reduction current of NAD were reported.     

主动锁模光纤激光器的孤子理论分析

系统考虑了光纤激光器腔构参数与锁模脉冲参数的制约关系,建立了完整形式的振幅调制主动锁模光纤激光器的稳态方程;据此方程分析了主动锁模光纤激光器腔参数对锁模孤子脉冲参数的影响;分析了无啁啾孤子脉冲形成条件。