Salicylate ion-selective electrode based on new tetranuclear copper complexes of O-vannlin-methionine as neutral carriers.

A new salicylate-selective PVC membrane electrode based on a new Schiff base tetranuclear copper complex of O-vannlin-methionine (Cu(II)(4)-TVM) as a neutral carrier is described. This electrode displays a preferential potentiometric response to salicylate and an anti-Hofmeister selectivity sequence in the following order: Sal(-) > ClO(4)(-) > SCN(-) > I(-) > NO(2)(-) > NO(3)(-) > Br(-) > Cl(-) > SO(3)(2-) > SO(4)(2-) > H(2)PO(4)(-). The electrode exhibits near-Nernstian potential linear range of 1.5 x 10(-6)-1.0 x 10(-1) M with a detection limit of 8.0 x 10(-7) M and a slope of -56.3 mV/decade in pH 3.0-8.0 of phosphorate buffer solution at 20 degrees C. Thanks to the tetranuclear copper(II) in the carrier, the electrode has the advantages of simplicity, fast response, fair stability and reproducibility and low detection limit. The response mechanism to the electrodes is discussed by the a.c. impedance technique and the UV spectroscopy technique. The electrode can be applied to analyses of medicine and the results obtained are in fair agreement with the results given by a standard method.     

Vinyl polymerization of norbornene by mono‐ and trinuclear nickel complexes with indanimine ligands

A series of new indanimine ligands [ArN?CC₂H₃(CH₃)C₆H₂(R)OH] (Ar = Ph, R = Me ( 1 ), R = H ( 2 ), and R = Cl ( 3 ); Ar = 2,6‐i‐Pr₂C₆H₃, R = Me ( 4 ), R = H ( 5 ), and R = Cl ( 6 )) were synthesized and characterized. Reaction of indanimines with Ni(OAc)₂·4H₂O results in the formation of the trinuclear hexa(indaniminato)tri (nickel(II)) complexes Ni₃[ArN = CC₂H₃(CH₃)C₆H₂(R)O]₆ (Ar = Ph, R = Me ( 7 ), R = H ( 8 ), and R = Cl ( 9 )) and the mononuclear bis(indaniminato)nickel (II) complexes Ni[ArN?CC₂H₃(CH₃)C₆H₂(R)O]₂ (Ar = 2,6‐i‐Pr₂C₆H₃, R = Me ( 10 ), R = H ( 11 ), and R = Cl ( 12 )). All nickel complexes were characterized by their IR, NMR spectra, and elemental analyses. In addition, X‐ray structure analyses were performed for complexes 7 , 10 , 11 , and 12 . After being activated with methylaluminoxane (MAO), these nickel(II) complexes can polymerize norbornene to produce addition‐type polynorbornene (PNB) with high molecular weight M_v (10⁶ g mol^?1), highly catalytic activities up to 2.18 × 10⁷ gPNB mol^?1 Ni h^?1. Catalytic activities and the molecular weight of PNB have been investigated for various reaction conditions. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 489–500, 2008     

基于光电成像系统最小可分辨对比度的扩展源目标作用距离模型

可见光/近红外光电成像系统的作用距离预测是实际系统总体设计的重要环节.为了使系统的预测及性能评价更准确.研究了光电成像系统对扩展源日标的作用距离预测方法,给出了最小可分辨对比度(MRC)的定义及其测量方法,提出了基于MRC的作用距离模型;通过结合实际系统分析,讨论了模型的计算过程及其特点.由于综合考虑了,日标与背景特性、环境路径和大气特性、光电成像系统特性以及人眼视觉特性等因索,提出的作用距离预测方法较传统基于瞬时视场(IFOV)的极限分辨角方法更为合理科学,可有效地进行陆上、海上以及航空航人遥感等可见光/近红外光电成像系统的性能评价.     

Synthesis and Biological Evaluation of 3,3-Dimethyl-1-(1H-1,2,4-triazole-1-yl)butan-2-One Derivatives as Plant Growth Regulators

We synthesized nine novel triazole-compoimds and investigated their plant growth regulatory activity.Compoimd CGR3,with metlioxvacyl on 3-position of triazole ring,showed better activity,promoting root length not only for mungbean,but also tor wheat.Additionally,CGR3 changed the level of endogenous hormones in mungbean roots,the most obvious effect was the increase of IAA,being 4.9 times greater than that of the control at the 96th hour after treatment.Among the synthesized new 1,2,4-triazol derivatives,CGR3 could be applied as a new agrochemical,functioning as a root growth stimulant,which promotes primary root length,influences the levels of endogenous honnones(IAA,ABA and GA3)to play an important role in controlling the primary root development.     

Improved stability and dispersity of ZnO@PANI nanocomposites aqueous suspension

The high dispersion and stability of a nanocomposites suspension are required as a crucial factor in many of their applications. In this study, ZnO nanosheets covered with polyaniline (PANI) thin layer (ZnO@PANI) were synthesized by a simple in‐situ polymerization. The as‐prepared ZnO@PANI powders were well characterized by XRD, Raman, FTIR, XPS and photoluminescence spectra, as well as SEM and TEM techniques. The effect of PANI incorporation on the chemical dissolution and dispersing stability of ZnO aqueous suspension was investigated. Dissolution experiments showed that the dissolution of ZnO was effectively restrained by the surface‐hybridized PANI layer. ZnO@PANI suspension can be more stable in a wider pH range. Dynamic Light Scattering (DLS) analysis indicated that ZnO@PANI particles were thoroughly dispersed in the neutral and alkaline solution as proven by the emergence of a single distribution with a high diffused intensity. Sedimentation experiments suggested that ZnO@PANI suspension was a more stable dispersion taking into account the effect of pH and ionic strength.     

Enhanced microfiltration devices configured with hydrodynamic trapping and a rain drop bypass filtering architecture for microbial cells detection

Ultra-fine (<1 microm) microfilters are required to effectively trap microbial cells. We designed microfilters featuring a rain drop bypass architecture, which significantly reduces the likelihood of clogging at the cost of limited cell loss. The new rain drop bypass architecture configuration has a substantially lower pressure drop and allows a better efficiency in trapping protozoan cells (Cryptosporidium parvum and Giardia lamblia) in comparison to our previous generation of a microfilter device. A modified version displaying sub-micron filter gaps was adapted to trap and detect bacterial cells (Escherichia coli), through a method of cells labeling, which aims to amplify the fluorescence signal emission and therefore the sensitivity of detection.     

两种新型溶致型液晶芳香聚酯酰胺的合成与表征

从单体4,4′-对苯二甲酸酯基二苯甲酰氯制备开始,合成了三种可在N-甲基吡咯烷酮(NMP)中溶解且特性粘数较高的溶致液晶芳香聚酯酰胺。其中酰氯单体与4,4′-二氨基二苯甲烷反应生成的聚酯酰胺粘度较高,其NMP溶液25℃下的特性粘数可达1.7dl/g。这种聚酯酰胺具有交替的酯、酰胺基结构,其NMP溶液浓度为15%时在偏光显微镜下可观察到明显的液晶双折射,并且可以刮板成膜。     

过氧亚硝基阴离子对重组人干扰素α2b的氧化硝化修饰特征

在体外模拟研究体内氧化硝化应激状态下产生的过氧亚硝基阴离子(ONOO^－)对重组人干扰素α2b (rhIFN α2b)造成的氧化硝化修饰特征, 并利用HPLC-MS/MS分析方法鉴定了ONOO^－对重组人干扰素α2b氨基酸序列中的氧化硝化位点. 结果表明ONOO^－对重组人干扰素α2b的修饰位点主要在A螺旋的Met16被氧化, DE颈环的Tyr135被硝化, 以及 E螺旋的Trp140被硝化修饰.     

流动注射荧光法测定脱氧核糖核酸

合成了新配体２－苯基（４－氯）咪唑〔ｆ〕邻菲咯啉（简称ＰＩＰ（Ⅱ）,并合成络合物Ｒｕ（ｂｐｙ）２ＰＩＰ（Ⅱ）,研究了该络合物与ＤＮＡ作用的荧光光谱,观察到５９０ｎｍ（λｅｘ＝４６０ｎｍ）处产生很强的荧光峰,采用流动注射法测定ＤＮＡ,该方法简便快速,灵敏度高。对合成样品测定获得满意结果。     

Rational Exploration of N‐Heterocyclic Carbene (NHC) Palladacycle Diversity: A Highly Active and Versatile Precatalyst for Suzuki–Miyaura Coupling Reactions of Deactivated Aryl and Alkyl Substrates

As less attention has been focussed on the design of highly efficient palladium precatalysts to ensure the smooth formation of the active catalyst for metal‐mediated cross coupling reactions, we herein demonstrate that combining the bulky N‐heterocyclic carbene (NHC) 1,3‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene (IPr) with cyclopalladated acetanilide as the optimal palladium precatalyst leads to superior catalytic activity compared with the state‐of‐the‐art NHC–Pd catalysts. The complex was discovered through the evaluation of a small, rationally designed library of NHC–palladacycles prepared by a novel, practical and atom‐economic method, the direct reaction of IPr?HCl with palladacycle acetate dimers.