Synthesis, crystal structure and magnetic property of the novel dinuclear nickel(II) complex with 4-(p-methoxyphenyl)-3,5-bis(pyridine-2-yl)-1,2,4-triazole

A novel dinuclear nickel(II) complex, [Ni₂(MOBPT)₂Cl₂(H₂O)₂]Cl₂ · 7H₂O (MOBPT = 4-(p-methoxyphenyl) −3,5-bis(pyridine-2-yl)-1,2,4-triazole), has been synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction methods. The crystal structure determination shows that the dinuclear Ni₂N₈ unit is almost planer in which each Ni^II ion is coordinated by four nitrogen atoms from MOBPT equatorially and a water molecule and a chloride ion axially in a distorted octahedral geometry. Magnetic measurements reveal a relatively weak antiferromagnetic exchange in the complex.     

氯化血红素催化新型荧光反应测定葡萄糖的研究

本文用流动注射分析了研究了过氧化物模拟酶催化过氧新型荧光底物（Ｎ，Ｎ－二氰甲基邻苯二胺，ＤＣＭＯＰＡ）的最优条件。结果表明，该系统可用于定量测定氧化氢及催化氯化血红素的浓度。     

Uniform Rice-like CdS Particles Prepared from Water-in-oil Microemulsions

IntroductionNano-sized semiconductors are of great interestdue to their special optical and electronic proper-ties[1,2].As one of the mostimportantⅡ—Ⅵsemicon-ductors,CdS has importantapplications in many fields,such as the solar cell field,non linear o…     

Hydrodynamic simulation of cell docking in microfluidic channels with different dam structures

The immobilization of biological cells in micro-devices requires high efficiency and easy control while maintaining cell viability. One approach for cell immobilization is to utilize constriction structures such as dams to trap cells in microfluidics. In this paper, we present a comprehensive hydrodynamic analysis of two different types of constriction structures for cell immobilization: dams either in perpendicular or in parallel to the main flow route. Various structural models and experimental conditions were compared for cell docking and alignment, and the pressure and velocity profiles of the flow in the micro-channels and the hydrodynamic force and shear stress on the docked cells were calculated based on fluid dynamic theory and numerical simulation. The effects of the dam structures and cell docking on the flow properties, the transportation efficiency, and the induced stress on the docked cells were analyzed. Improved hydraulic pressure profiles in the auxiliary inlets were discussed for the modulation of the flow characteristics and attenuation of hydrodynamic forces exerted on the cells. Furthermore, a new design combining the advantages of perpendicular and parallel dam structures was proposed for cell-based microfluidics.     

Characteristic sequences for DNA primary sequence

A DNA sequence can be identified with a word over an alphabet N = [A, C, G, T]. Characteristic sequences of a DNA sequence are given in term of classifications of bases of nucleic acids. Using the characteristic sequences, we construct a set of 2 x 2 matrices to represent DNA primary sequences, which are based on counting of the frequency of occurrence of all (0,1) triplets of characteristic sequences. Furthermore, the leading eigenvalues of these matrices are computed and considered as invariants for the DNA primary sequences. Similarity and dissimilarity analysis based on the characteristic sequences are given for eight exon-1 genes of beta-globin about eight species.     

Advanced Current Collectors for Alkali Metal Anodes

High-energy-density batteries are in urgent need to solve the ever-increasing energy storage demand for portable electronic devices, electric vehicles, and renewable solar and wind energy systems. Alkali metals, typically lithium(Li), sodium(Na) and potassium(K), are considered as the promising anode materials owing to their low electrochemical potential, low density, and high theoretical gravimetric capacities. However, the problem of dendrite growth of alkali metals during their plating/stripping process will lead to low Coulombic efficiencies, a short lifespan and huge volume expansion, eventually hindering their practical commercialization. To resolve this issue, a very effective approach is engineering the anodes on structured current collectors. This review summarizes the development of the alkali metal batteries and discusses the recent advances in rational design of anode current collectors. First, the challenges and strategies of suppressing alkali-metal dendrite growth are presented. Then the special attention is paid to the novel current collector design for dendrite-free alkali metal anodes. Finally, we give conclusions and perspective on the current challenges and future research directions toward advanced anode current collectors for alkali metal batteries.     

Zeolite NaY-mediated oxidation of dyes with H2O2: unique heterogeneous non-transition metal center cleavage of H2O2 under visible light irradiation

This study investigated the visible-light catalysis mediated by zeolite NaY on the oxidation of dyes with H₂O₂. The results demonstrated that zeolite NaY acts as a sink for the electron from the photo-excited dye in the heterogeneous catalysis. Furthermore, the electron can effectively activate H₂O₂ to produce ^·OH radical that is a powerful oxidant for the oxidation of dye at room temperature. The effects of the framework topology, Si/Al ratio, and exchangeable cation of the zeolite on the oxidation of various dyes were also shown.     

Ni的掺入对复合氧化物LaFeO3的结构及性质的影响

合成子Ｎｉ替代铁酸稀土复合氧化物ＬａＦ３１－ｘＮｉｘＯ３（ｘ＝０．１－０．６），对样品进行了ＸＲＤ、ＩＲ及Ｍｏｓｓｂａｕｅｒ谱测试，结果表明：ｘ＝０＼１，０＼２，０＼３的样品为正交相，ｘ＝０．５，０．６的样品为菱方相；伴随相结构从正交向菱方结构的转变，ＩＲ谱上Ｆｅ（Ｎｉ）－Ｏ键伸振动谱带向高频移动近２０ｃｍ＾－１，Ｍｏｓｓｂａｕｅｒ谱测试表明Ｆｅ均处于＋３自旋态，Ｎｉ离子以＋３价进入晶格。     

Rapid determination of underivatized pyroglutamic acid, glutamic acid, glutamine and other relevant amino acids in fermentation media by LC-MS-MS

Determination of amino acids in a complex matrix without derivatization is advantageous, however, difficulties are found in both the detection and the separation of those compounds. In this study, a rapid and reliable LC-MS-MS method for the quantitation of underivatized amino acids in exocellular media was established. Injections were made directly after centrifugation of the samples, without further preparation. The separation of seven underivatized amino acids was achieved on a reversed-phase C18 column with pentadecafluorooctanoic acid as a volatile ion-pair reagent, and the specific detection of most amino acids was achieved by MS-MS of the specific transitions [M + H]+-->[M + H - 46]+. The calibration curves of all analytes were linear over the range of 1.0-1000 microg ml(-1) and the detection limits ranged from 0.1 to 5 ng ml(-1), with an injection volume of 20 microl. The inter-day and intra-day precisions ranged from 2.6 to 5.7% and 4.8 to 8.2%, respectively; the mean recoveries of the seven analytes were 81-104%, 91-107% and 93-101% respectively at the spiked level of 10, 40 and 200 microg ml(-1). A large number of fermentation samples were analysed using this method. The technique is simple, rapid, selective and sensitive, and shows potential for the high-throughput quantitation of amino acids from other biological matrices.     

A highly stereoselective synthesis of the C10–C31 (BCDEF ring) portion of pinnatoxin A

An efficient, highly stereoselective synthesis of the C10–C31 (BCDEF ring) portion of pinnatoxin A has been achieved utilizing tandem double hemiketal formation/intramolecular hetero-Michael addition to construct the 6,5,6-dispiroketal (BCD ring) system and subsequent intramolecular ketalization to form the 5,6-bicycloketal (EF ring) system as key steps.