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11.
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
12.
13.
We explored matrix-assisted laser desorption/ionization (MALDI) tandem time-of-flight (TOF/TOF) mass spectrometry for the analysis of N-glycosylated peptides, using horseradish peroxidase (HRP) as a test case. Two different types of cleavage were observed in the TOF/TOF fragmentation spectra: Firstly, cleavages of peptide bonds yielded fragments with the attached N-glycans staying intact, thus revealing information on peptide sequence and glycan attachment site. Secondly, fragmentation of the glycan moiety was characterized by cleavage of glycosidic bonds as well as a (0,2)X-ring fragmentation of the innermost N-acetylglucosamine of the chitobiose core. Loss of the complete N-glycan moiety occurred by cleavage of both the N-glycosidic bond and the side-chain amide group of the N-glycosylated asparagine, yielding a characteristic peak doublet with a mass difference of 17 Da, which revealed the individual masses of the N-glycan and the peptide moiety. Analysis of a HRP tryptic digest at the sub-picomole level allowed the characterization of various N-glycosylated peptides including those with internal disulfide linkages, a glycopeptide linked via a disulfide bond to another peptide, and a 5 kDa glycopeptide carrying two N-glycans. The potential of our approach was illustrated by the detection of the following novel features of HRP glycosylation: (i) The conjugation of a xylosylated trimannosyl N-glycan without core-fucosylation to site Asn316, showing for the first time unambiguously the occupation of this site; and (ii) A disaccharide N-acetylhexosamine1deoxyhexose1 attached to N-glycosylation sites Asn285 and Asn298, which might represent a Fuc(alpha1-3)GlcNAc- moiety arising from the processing of N-glycans by a horse-radish endoglycosidase during biosynthesis of HRP. 相似文献
14.
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
15.
16.
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
17.
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
18.
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
19.
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
20.
By using polarization-rotated optical feedback from the transverse-electric (TE) mode to the transverse-magnetic (TM) mode,
chaotic oscillations for both polarization modes are excited in a semiconductor laser. We find different correlations between
these chaotic oscillations than those found in previous studies. In this study, the dynamics are strongly dependent on their
radio-frequency (RF) components and they are divided into three RF regions. For low-pass filtered signals lower than the laser
relaxation oscillation, there is an antiphase correlation between the two polarization modes. On the other hand, the two polarization
modes have an in-phase correlation for the RF components of the high-pass filtered signals, which are higher than the relaxation
oscillation. However, no correlations were observed between the two modes for the intermediate RF components that include
the relaxation oscillation frequency. We also perform numerical calculations for the model and obtain good agreement between
the theoretical and experimental results. 相似文献