Experimental optimization of p-polarized MAIR spectrometry performed on a fourier transform infrared spectrometer.

Optimized experimental conditions of infrared p-polarized multiple-angle incidence resolution spectrometry (p-MAIRS) for the analysis of ultrathin films on glass have been explored. When the original MAIRS technique is employed for thin-film analysis on a substrate of germanium or silicon, which exhibits a high refractive index, an established experimental condition without optimization can be adapted for the measurements. On the other hand, the p-MAIRS technique that has been developed for analysis on a low-refractive-index material requires, however, optimization of the experimental parameters for a 'quantitative' molecular orientation analysis. The optimization cannot be performed by considering only for optics in the spectrometer, but for optics concerning the substrate should also be considered. In the present study, an optimized condition for infrared p-MAIRS analysis on glass has been revealed, which can be used for quantitative molecular orientation analysis in ultrathin films on glass.     

Synthesis of ABA‐triblock and star‐diblock copolymers with poly(2‐adamantyl vinyl ether) and poly(n‐butyl vinyl ether) segments: New thermoplastic elastomers composed solely of poly(vinyl ether) backbones

ABA‐type triblock copolymers and AB‐type star diblock copolymers with poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] hard outer segments and poly(n‐butyl vinyl ether) [poly(NBVE)] soft inner segments were synthesized by sequential living cationic copolymerization. Although both the two polymer segments were composed solely of poly(vinyl ether) backbones and hydrocarbon side chains, they were segregated into microphase‐separated structure, so that the block copolymers formed thermoplastic elastomers. Both the ABA‐type triblock copolymers and the AB‐type star diblock copolymers exhibited rubber elasticity over wide temperature range. For example, the ABA‐type triblock copolymers showed rubber elasticity from about ?53 °C to about 165 °C and the AB‐type star diblock copolymer did from about ?47 °C to 183 °C with a similar composition of poly(2‐AdVE) and poly(NBVE) segments in the dynamic mechanical analysis. The AB‐type star diblock copolymers exhibited higher tensile strength and elongation at break than the ABA‐type triblock copolymers. The thermal decomposition temperatures of both the block copolymers were as high as 321–331 °C, indicating their high thermal stability. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

Is Auger-free luminescence present in CeF3?

It is well known that Auger-free luminescence (AFL) is observable when the condition E_g>E_VC is satisfied, where E_g is the band-gap energy between the lowest unoccupied band and the highest occupied band and E_VC the energy difference between the top of the highest occupied band and the top of the next lower occupied band. From measurements of reflection and X-ray photoelectron spectra, CeF₃ is demonstrated to really satisfy this condition. No evidence for AFL is found, nevertheless. The absence of AFL in CeF₃ is related to a characteristic nature of its highest and next lower occupied bands, which are quite different from those of previously studied AFL-materials.     

Preparation of three‐dimensional poly(dimethylsiloxane) (PDMS) with movable cross‐linking

A pentamethylcyclotrisiloxane moiety was introduced into cyclic polystyrene (cPSt) and cyclic PDMS (cPDMS) to obtain noncovalent cross‐linking agents, D₃‐cPSt and D₃‐cPDMS, respectively. Anionic ring‐opening polymerization of octamethylcyclotetrasiloxane (D₄) in nitrobenzene was carried out in the presence of D₃‐cPSt to obtain a cloudy white PDMS gel as a precipitation. On the other hand, bulk copolymerization of D₃‐cPDMS with D₄ proceeded in a homogeneous state to give a colorless transparent PDMS gel in high yield. The formation of mechanically linked PDMS with movable cross‐linking was indicated by control experiment. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5882–5890, 2009     

Aerobic photooxidative cleavage of 1,3-diketones to carboxylic acids using 2-chloroanthraquinone

We developed direct aerobic photooxidation of 1,3-diketones to corresponding carboxylic acids in the presence of a catalytic amount of 2-chloroanthraquinone under visible light irradiation from fluorescent lamps.     

Enhancement in thermal stability and resistance to denaturants of lipase encapsulated in mesoporous silica with alkyltrimethylammonium (CTAB)

We assembled a highly durable conjugate with both a high-density accumulation and a regular array of lipase, by encapsulating it in mesoporous silica (FSM) with alkyltrimethylammonium (CTAB) chains on the surface. The activity for hydrolyzing esters of the lipase immobilized in mesoporous silica was linearly related to the concentration of lipase, whereas that of non-immobilized lipase showed saturation due to self-aggregation at a high concentration. The lipase conjugate also had increased resistance to heating when stayed in the silica coupling with CTAB. In addition, encapsulating the enzyme with FSM coupled CTAB caused the lipase to remain stable even in the presence of urea and trypsin, suggesting that the encapsulation prevented dissociation and denaturing. This conjugate had much higher activity and much higher stability for hydrolyzing esters when compared to the native lipase. These results show that FSM provides suitable support for the immobilization and dispersion of proteins in mesopores with disintegration of the aggregates.     

Explicit study on the oxidation mechanism of nickel in molten Li2CO3-K2CO3

The oxidation behavior of nickel in Li+K carbonate melt is followed by measuring the open-circuit potential and by electrochemical impedance spectroscopy under an O₂+CO₂ gas mixture in the ratio 90/10 at a total pressure of 1 atm at 650 °C. X-ray diffraction (XRD) and energy-dispersive spectroscopy are employed for qualitative and quantitative analyses of the different compounds involved during the oxidation of nickel. Atomic force microscopy is used for both imaging the evolution of the oxide layer and determining its surface roughness. The in situ oxidation process of nickel demonstrates three stages: rapid formation of a compact surface oxide (first stage), thicker oxide layer (second stage), and a porous oxide structure (third stage). The lithiation reaction has been identified to occur during the second stage. Formation of an intermediate and unstable compound, namely NiCO₃, has been confirmed by XRD. Electronic Publication     

锆诱导的五元环化合物的新和成

由锆杂五元环化合物出发合成五元环有机化合物,只要求一个碳单元并且形成两个碳-碳链,从以下四个方面描述了利用锆杂环化物合成五元环有机化合物的新合成方法：(1)CO或RNC的插入反应;(2)与丙炔酸酯的加成反应-峡谷次的Michael加成;(3)与碘代丙烯酸酯或碘代环烯酮的偶联加成反应-先偶联后Michael加成;(4)与酰氯的取代加成反应-先亲核取代后亲核加成,每类反应都含有数个简单反应类型。     

Theoretical Study of the Structure of the Electric Field in Helical Toroidal Plasmas

A set of transport equations is analyzed, including the bifurcation of the electric field. The structure of the electric field is studied by use of the theoretical model for the anomalous transport diffusivities. A steep gradient of the radial electric field (E _r) is obtained at the electric domain, where the electric domain is the structure of the electric field in which the ambipolar E _r spatially changes from the electron root (E _r>0) to the ion root (E _r<0). The suppression of the anomalous transport diffusivity is studied in the presence of a strong shear of the electric field. The hard transition between the multiple ambipolar solutions in the structure of the radial electric field is examined. The details of the structure of the electric domain interface are investigated.