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11.
Fukui K Takada Y Sumiyoshi T Imai T Takahashi K 《The journal of physical chemistry. B》2006,110(32):16111-16116
The fragmentation of peptides and oligosaccharides in the gas phase was investigated by means of electrospray ionization Fourier transform ion cyclotron resonance (FTICR) mass spectrometry coupled with dissociation by a laser-cleavage infrared multiphoton dissociation (IRMPD) technique. In this technique, an IR free-electron laser is used as a tunable source of IR radiation to cause cleavage of the ionized samples introduced into the FTICR cell. The gas-phase IRMPD spectra of protonated peptides (substance P and angiotensin II) and two sodiated oligosaccharides (sialyl Lewis X and lacto-N-fucopentaose III) were obtained over the IR scan range of 5.7-9.5 microm. In the IRMPD spectra for the peptide, fragment ions are observed as y/b-type fragment ions in the range 5.7-7.5 microm, corresponding to cleavage of the backbone of the parent amino acid sequence, whereas the spectra of the oligosaccharides have major peaks in the range 8.4-9.5 microm, corresponding to photoproducts of the B/Y type. 相似文献
12.
Yusuke Himei Tomohiro Nagakane Naoyuki Kitamura Akihiko Sakamoto 《Journal of Non》2008,354(27):3113-3119
Reduction in the temperature coefficient of the optical path length, dS/dT of Li2O-Al2O3-SiO2 glass-ceramics with near-zero thermal expansion coefficient was attempted using control of the temperature coefficient of electronic polarizability, ?, and the thermal expansion coefficient, α. The dS/dT value of 2.6 mol% B2O3-doped glass-ceramic was 12.5 × 10−6/°C, which was 0.9 × 10−6/°C smaller than that of B2O3-free glass-ceramic. On the other hand, reduction in dS/dT through B2O3 doping was not confirmed in precursor glasses. Results showed that reduction in dS/dT of the glass-ceramic through B2O3 doping is caused by the reduction in ?. The reduction in ? from B2O3 doping was probably attributable to numerical reduction in non-bridging oxide ions with larger ? value by the concentration of boron ions in the residual glass phase. In addition, application of hydrostatic pressure during crystallization was effective to inhibit precipitation of β-spodumene solid solution, which thereby decreases dS/dT. The dS/dT value of B2O3-doped glass-ceramic crystallized under 196 MPa was 11.7 × 10−6/°C. That value was slightly larger than that of silica glass. The α value of this glass-ceramic was smaller than that of silica glass. 相似文献
13.
Yoshinori Kamiya Takuji Hirose Keishin Mizoguchi Yasutoshi Naito 《Journal of Polymer Science.Polymer Physics》1986,24(7):1525-1539
A gravimetric method for determining precisely the solubility of gases in polymers at high pressure is described. The solubilities of N2 and CO2 in low-density polyethylene (LDPE); CO2 in polycarbonate (PC); and N2, CH4, C2H6, and CO2 in polysulfone (PSUL) have been measured as a function of pressure up to 50 atm. Most of the measured sorption isotherms agreed closely with published data, but reproducible and time-dependent hysteresis in the sorption of CO2, C2H6, and CH4 in glassy polymers, PC, and PSUL, was observed in this study for the first time. Like the well known conditioning effect of high-pressure CO2 on the sorption capacity of glassy polymers, these hysteresis phenomena are believed to be due to the plasticizing effect of sorbed gases. On the basis of the current data, the dual-mode sorption model including the plasticization by sorbed gas is discussed and a primitive equation for the concentration of sorbed gases in a quasiequilibrium state of sorption or desorption is proposed. 相似文献
14.
15.
The transition between phase I and phase III in sodium sulfate (Na2SO4) was studied by high temperature X-ray diffraction and the calculation of diffraction patterns. An intermediate phase (phase II) was detected on cooling in the undoped and 1.7 at.% yttrium-doped Na2SO4, but not observed in the 3.8 at.% Y-doped sample. The DTA and X-ray diffraction results of the III ? I transition were explained well by a proposed model which consisted mainly of the following steps: (i) the rotation of the SO4 tetrahedra, and (ii)the disappearance of interfaces among the transformed domains. 相似文献
16.
17.
Hiroyuki Noguchi Toshiyasu Kiyabu Kazuhiro Hasezaki Yasutoshi Noda 《Journal of Physics and Chemistry of Solids》2007,68(1):91-95
Pb- or Sn-doped Bi88Sb12 alloys were prepared by direct melting, quenching, and annealing. The Bi-Sb alloy phase was predominant in all samples. Pb or Sn atoms were distributed almost uniformly in Bi88Sb12, while some segregation was confirmed at the grain boundaries when Pb or Sn was involved heavily. The thermoelectric properties of these doped materials were investigated by measuring the Hall coefficient, electrical resistivity, and Seebeck coefficient between 20 K and 300 K. The Hall and Seebeck coefficients of Pb- or Sn-doped samples were positive at low temperatures, indicating that the doping element acted as an acceptor. Temperatures resulting in positive Hall and Seebeck coefficients further increased with increasing doping amount and with respect to the annealing process. As a result, a large power factor of 1.2 W/mK2 could be obtained in the 3-at% Sn-doped sample at 220 K, with a large positive Seebeck coefficient. 相似文献
18.
The optical absorption and emission induced by electron irradiation of Na+-doped KCl was measured and new absorption and emission bands which decay at the same time constant were found and ascribed to the self-trapped exciton perturbed by Na+ impurity. 相似文献
19.
Takeshi Abe Ningyu Gu Yasutoshi Iriyama Zempachi Ogumi 《Journal of fluorine chemistry》2003,123(2):279-282
For enhancement of lithium-ion transference number, lithium-ion-conductive polymer electrolytes have been prepared from polyethylene oxide (PEO), lithium salt of LiCF3SO3 or LiF, plasticizer of polyethylene glycol dimethylether (PEGDME), and anion receptor of tris(pentafluorophenyl)borane (TPFB). Transport properties of the resultant polymer electrolytes have been studied by AC impedance spectroscopy. As a result, lithium-ion transference number increased with increasing TPFB due to the restriction of anion conduction by the interaction between anion and anion receptor. Effects of anion receptor on transport properties are discussed. 相似文献
20.
K Miyazaki Y Kato T Matsui S Hayashi Y Iriyama T Fukutsuka T Abe Z Ogumi 《Physical chemistry chemical physics : PCCP》2012,14(31):11135-11138
A high proton-conducting phase appears in the composites of zirconium- and titanium-oxide nanoparticles and polyphosphoric acid (HPO(3)). Metal oxide nanoparticles (ZrO(2) and TiO(2)) react with HPO(3) and form composite electrolytes containing pyrophosphates (ZrP(2)O(7) or TiP(2)O(7)) and shortened HPO(3) chains. The ZrO(2)-HPO(3) composite exhibits eleven times higher conductivity than sole HPO(3) at the maximum. A formed layer of shortened HPO(3) chains surrounding the pyrophosphates enhances the proton conductivities of the composite electrolytes and reduces the activation energies for the proton conductivities from 50 to 30 kJ mol(-1). 相似文献