Crystal structure and the role of cation group factor in the third‐order nonlinear optical properties of cadmium complexes constructed by 1,3‐dithiole‐2‐thione‐4,5‐dithiolato ligand

A cadmium complex bis(benzyltriethylammonium) bis(1,3‐dithiole‐2‐thione‐4,5‐dithiolato)‐cadmium(II) ((TEBA)₂[Cd(DMIT)₂]) has been synthesized and its crystal structure has been determined by means of X‐ray single‐crystal diffraction. The central cadmium(II) ion coordinates with two DMIT, which constructed a distorted tetrahedron environment. Its third‐order nonlinear optical properties have been studied using Z‐scan technique with 20 ps pulses at wavelength 1064 nm. Its third‐order nonlinear susceptibility χ⁽³⁾ value was determined to be 1.24 × 10⁻¹⁹ m² V⁻², the figure of merit, χ⁽³⁾/α₀, was estimated to be 2.64 × 10⁻²⁰ m³ V⁻². Copyright © 2011 John Wiley & Sons, Ltd.     

Effect of heat transfer on the oscillatory behavior in partial oxidation of methane over nickel catalyst

Monte Carlo method was applied to simulate the oscillatory behavior during partial oxidation of methane under non-isothermal condition. The simulation was performed to examine the influences of heat transfer constant and particle size on the kinetic oscillation. The oscillatory period and amplitude were observed to increase with the increase of heat transfer constant. The increase of catalyst particle size was found to result in short oscillatory period and more or less regular oscillations combined with the formation of oxide down to L=100.     

麦哲伦海山群富钴结壳铈富集的控制因素

利用ICP-OES和ICP-MS,分析了麦哲伦海山群西北端MK海山2170 m水深的MKD23B-3号富钴结壳样品,获得了其剖面上Ce,Co和P2O5含量数据.结果显示,该样品未磷酸盐化壳层的过剩Ce(Cexs)与Co含量之间呈明显的正相关关系,相关系数R2高达0.7893;与生长速率呈负相关关系,相关系数R2高达0.7211,表明壳层生长速率是制约结壳Ce含量的主因,高的Ce含量是低的生长速率造成的.在假设海水pH,Mn2+等条件不变的前提下,结壳生长速率正相关于Fe,Mn的沉积通量,而Fe,Mn的沉积通量正相关于海水中溶解氧含量.因此,在海水pH,Mn2+等条件不变的前提下,Cexs负相关于海水中溶解氧含量,海水溶解氧含量只是制约结壳Ce含量的间接因素,纠正了"结壳高Ce异常指示其形成时海水中高溶解氧含量"的认识.     

Improved detection of reactive metabolites with a bromine‐containing glutathione analog using mass defect and isotope pattern matching

Drug bioactivation leading to the formation of reactive species capable of covalent binding to proteins represents an important cause of drug‐induced toxicity. Reactive metabolite detection using in vitro microsomal incubations is a crucial step in assessing potential toxicity of pharmaceutical compounds. The most common method for screening the formation of these unstable, electrophilic species is by trapping them with glutathione (GSH) followed by liquid chromatography/mass spectrometry (LC/MS) analysis. The present work describes the use of a brominated analog of glutathione, N‐(2‐bromocarbobenzyloxy)‐GSH (GSH‐Br), for the in vitro screening of reactive metabolites by LC/MS. This novel trapping agent was tested with four drug compounds known to form reactive metabolites, acetaminophen, fipexide, trimethoprim and clozapine. In vitro rat microsomal incubations were performed with GSH and GSH‐Br for each drug with subsequent analysis by liquid chromatography/high‐resolution mass spectrometry on an electrospray time‐of‐flight (ESI‐TOF) instrument. A generic LC/MS method was used for data acquisition, followed by drug‐specific processing of accurate mass data based on mass defect filtering and isotope pattern matching. GSH and GSH‐Br incubations were compared to control samples using differential analysis (Mass Profiler) software to identify adducts formed via the formation of reactive metabolites. In all four cases, GSH‐Br yielded improved results, with a decreased false positive rate, increased sensitivity and new adducts being identified in contrast to GSH alone. The combination of using this novel trapping agent with powerful processing routines for filtering accurate mass data and differential analysis represents a very reliable method for the identification of reactive metabolites formed in microsomal incubations. Copyright © 2010 John Wiley & Sons, Ltd.     

Synthesis and characterization of green to orange electroluminescent copolymers derived from fluorene and 2,3-dimethylnaphthalopyrazine

Series of high molecular weight, readily soluble copolymers were synthesized by Suzuki palladium catalyzed coupling reaction from 9,9-dioctylfluorene and 2,3-dimethylnaphthopyrazine. The absorption, electrochemical and photoluminescence properties of the copolymers were studied. The external electrolu-minescence efficiencies in the devices of configuration indium-tin oxide/polyethylenedioxythiophene-polystyrene sulfonic acid/poly(fluorene-naphthopyrazine)/barium/aluminium varied with the copolymers composition, and the electroluminescence emission peaks of the copolymers were red-shifted from 530 nm to 584 nm as 2,3-dimethylnaphthopyrazine mole contents increasing from 0.5% to 30%. The best device performance was observed for devices fabricated with the copolymer of 2,3-dimethylnathphpyrazine 5% mole contents, showed maximum external quantum efficiency of 1.38% and electroluminescence peaks at around 537 nm.     

Synthesis,characterization, and properties of amphiphilic chitosan copolymers with mixed side chains by click chemistry

Novel amphiphilic chitosan copolymers with mixed side chains of poly(ε‐caprolactone) and poly(ethylene oxide) (CS‐g‐PCL/PEO) were successfully synthesized by “graft to” approach via click chemistry. The melting and crystallization behaviors and crystalline morphology of CS‐g‐PCL/PEO copolymers can be adjusted by the alteration of the feed ratio of PCL and PEO segments. CS‐g‐PCL/PEO copolymers revealed crystalline morphology different from that of linear alkynyl PCL and alkynyl PEO due to the influence of brush structure of copolymers and the mutual influence of PCL and PEO segments. The hydrophilicity of the CS copolymers can be improved and adjusted by the alteration of the composition of PCL and PEO segments. Moreover, the CS copolymers can self‐assemble into spherical micelles in aqueous solution. Investigation shows that the size of the CS copolymer micelles increased with the increase of the content of hydrophobic PCL segments in copolymers, which indicated that the micellar behavior of the copolymers can be controlled by the adjustment of the ratio of PCL and PEO segments in copolymer. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3476–3486, 2010     

Application of 28Mg to the kinetic study of Mg uptake by rice plants

The time course of Mg uptake and release using intact rice plants and ²⁸Mg as a tracer is presented. Since there is no conventional Mg tracer available, ²⁸Mg was produced via ²⁷Al(α, 3p)²⁸Mg reaction using a cyclotron. Using the purified ²⁸Mg tracer, it was found that the uptake amount of ²⁸Mg by the rice plants increased linearly during 30 min of application. After ²⁸Mg treatment for 90 min, the roots were sequentially washed with iced solution for 120 min. Within about 10 min, almost all of the ²⁸Mg, that was thought to be weakly bound to the apoplast, was washed away.     

Simulation of container filling process with two inlets by improved smoothed particle hydrodynamics (SPH) method

In this article, an improved smoothed particle hydrodynamics (SPH) method is proposed to simulate the filling process with two inlets. Improvements are achieved by deriving a corrected kernel gradient of SPH and a density re-initialisation. In addition, a new treatment of solid wall boundaries is presented. Thus, the improved SPH method has higher accuracy and better stability, and conserves both linear and angular momentums. The validity of the new boundary treatment is shown by simulating the spin-down problem. The bench tests are also presented to demonstrate the performance of the improved SPH method. Then the filling process with a single inlet is simulated to show the ability to capture complex-free surface of the proposed method. Finally, the filling process with two inlets is numerically investigated. The numerical results show that the filling patterns are affected significantly by Reynolds number, aspect ratio of the container and the location of the inlets.