Thermogravimetric analysis with gas chromatograph mass spectrometry of Japanese fir wood (Abies sachalinensis) in helium with or without steam–oxygen

Thermal properties of a kind of Japanese fir wood (Abies sachalinensis) were thermogravimetrically analyzed and produced compounds were gas chromatograph mass spectrometrically analyzed for basic study of biomass gasification. Atmosphere during each analysis was controlled to be helium alone or helium with steam–oxygen. Compounds identified in this series of measurements were roughly classified into three groups: (a) phenol and its derivatives, (b) oxygenated cyclic compounds, and (c) oxygenated compounds of low molecule. Their production rates were dependent on both temperature and atmosphere, which well explained high carbon conversion rate from feedstock to gas of advanced gasification technologies, such as entrained-flow type gasification, and high yields of solid and liquid residues of traditional gasification technologies, such as fixed-bed type gasification.     

Element analysis and radioactivity measurement within a wood disk by neutron activation analysis

We have analyzed 16 elements and the radioactivity of ²¹⁰Pb in a wood disk, across the annual rings to find out a promising tool for dendrochronology (chronology of wood) both for a Japanese wood, Cryptomeria japonica, and for an Indonesian rain forest wood, Alstonia, which does not form annual rings because of the relatively constant climate of the rain forest. As a result, only Mg concentration showed similar, smooth decreasing tendency in both wood species. The smooth change of the Mg concentration across the annual rings along with the growth suggested the possibility of the Mg concentration determination as a promising dendrochronological tool.     

Enhanced magnetic properties of Nd–Fe–B thin films crystallized by heat treatment

Nd₂Fe₁₄B Φ phase crystallites were formed in Nd_16.7Fe_65.5B_17.8 thin films prepared by RF sputtering with subsequent heat treatment. The 2 μm-thick films were deposited onto 0.1 mm Mo sheets at an average substrate temperature (T_s) of 365°C. The enhanced magnetic properties of the magnetically anisotropic thin films were investigated using different heating rates (h_r) of 10°C, 20°C, 50°C and 100°C/min in an annealing experiment. Transformation from the amorphous phase to the crystalline phase is clearly manifested by the formation of fine crystallites embedded as a columnar matrix of Nd₂Fe₁₄B phase. High-resolution scanning electron microscope data of the cross-section of the annealed films show columnar stacking of Nd₂Fe₁₄B crystallites with sizes <500 nm. Transmission electron microscope observations revealed that the microstructure of these films having out-of-plane magnetization consists of uniformly distributed Φ phase with grain size around 400 nm together with small Nd rich particles. This grain size of Φ phase is comparable to the single domain particle diameter of Nd₂Fe₁₄B. Significant change in _iH_c, 4πM_r and 4πM_s with h_r was confirmed. Annealing conditions with a heating rate of 50°C/min to an annealing temperature (T_a) of 650°C for 30 min was consequently found to give optimum properties for the NdFeB thin films. The resulting magnetic properties, considered to be the effect of varying h_r were _iH_c= 1307–1357 kA/m, 4πM_r=0.78–1.06 T and 4πM_s=0.81–1.07 T.     

Modified Wave Operators for the Hartree Equation with Data,Image and Convergence in the Same Space,II

We study modified wave operators for the Hartree equation with a long-range potential |x|^-n |x|^{-\nu} , extending the result in [12] to the whole range of the Dollard type 1/2 < n \nu < 1. We construct the modified wave operators in the whole space of (1 + |x|)^-sL² (1 + |x|)^{-s}L^2 . We also have the image, strong continuity and strong asymptotic approximation in the same space. The lower bound $ s > 1 - \nu / 2 $ s > 1 - \nu / 2 of the weight is sharp from the scaling argument. Those maps are homeomorphic onto open subsets, which implies in particular asymptotic completeness for small data.     

Growth of ZnInGaS4 by normal freezing method

The crystal structure and phase transition of ZnInGaS₄ were described. The ZnInGaS₄ had both a defect chalcopyrite and a layered structure below 920 °C, and only the layered structure ZnInGaS₄ existed between 920 and 1020 °C. The layered structure ZnInGaS₄ was grown using the normal freezing method. The bandgap of the layered structure ZnInGaS₄ was estimated to be approximately 2.6 eV and it is possibly a direct bandgap. This is a first step toward realizing the novel functions of ZnInGaS₄.     

Side‐chain crystallization behavior of graft copolymers consisting of amorphous main chain and crystalline side chains: Poly(methyl methacrylate)‐graft‐poly(ethylene glycol) and poly(methyl acrylate)‐graft‐poly(ethylene glycol)

Graft copolymers consisting of amorphous main chain, poly(methyl methacrylate) (PMMA), or poly(methyl acrylate) (PMAc), and crystalline side chains, poly(ethylene glycol) (PEG), have been prepared by copolymerization of PEG macromonomers with methyl methacrylate or methyl acrylate (MMAx or MACx, respectively). Because of the compatibility of PMMA/PEG and PMAc/PEG, from small‐angle X‐ray scattering results, the main and side chains in graft copolymers were suggested to be homogeneous in the molten state. Differential scanning calorimetry (DSC) cooling scans revealed that PEG side chains for graft copolymers with large PEG fractions were crystallized when the sample was cooled, with a cooling rate of 10 °C/min. The spherulite pattern observed by a polarized optical microscope suggested the growth of PEG crystalline lamellae. Crystallization of PEG in MMAx was more restrained than in MACx. From these results, we have concluded that the crystallization behavior of the grafted side chains is strongly influenced by the glass transition of a homogeneously molten sample as well as dilution of the crystallizable chains. Domain spacings for isothermally crystallized graft copolymers were described by interdigitating chain packing in crystalline–amorphous lamellar structure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 79–86, 2005     

Fabrication of χ{2) Grating in Poled Polymer Waveguide Based on Direct Laser Beam Writing

A simple method is described for fabricating high resolution χ⁽²⁾ grating in poled polymer waveguide. It is found that the second-order nonlinearity of corona-poled polymer thin film is erased after visible laser (450 nm) irradiation. The mechanism of the erasure of χ^{2) is discussed. High resolution χ⁽²⁾ grating structure in several poled polymer waveguides is demonstrated by direct writing with a cw He-Cd laser.On leave from the Department of Optical Instruments, Zhejiang University, Hangzhou, Zhejiang Province, 310027, P.R. of China.     

Weil-Petersson Areas of The Moduli Spaces Of Tori

We study the Teichmüller spaces of torus with one branch point of order v and of torus with a totally geodesic boundary curve of length m, respectively. Applying the obtained results for the corresponding moduli spaces we find that the Weil-Petersson area of the moduli space of torus with one conical point of order v is (π²/6)(1 - l/v²) and that of the moduli space of torus with a totally geodesic boundary curve of length m is π²/6 + m²/24.