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751.
Kawai H Katoono R Nishimura K Matsuda S Fujiwara K Tsuji T Suzuki T 《Journal of the American Chemical Society》2004,126(16):5034-5035
The preparation and complexation properties of a hydrindacene-based exoditopic receptor, that exhibits a positive homotropic allosteric binding process toward benzenediols, are described. The exoditopic receptors form 1:2 complexes with resorcinols, catechol, and 3-hydroxybenzyl alcohol with K2/K1 = 3-33. Both the entropy and the enthalpy terms are important in this allosteric system; the crystallographic studies provide the first clear evidence that the cooperativity in amide hydrogen bonding by polarization contributes to the positive homotropic allosteric binding property. 相似文献
752.
753.
Yamada K Kurahashi K Uefuji T Fujita M Park S Lee SH Endoh Y 《Physical review letters》2003,90(13):137004
We report neutron scattering studies on two single crystal samples of the electron-doped (n-type) superconducting (SC) cuprate Nd2-xCexCuO4 (x=0.15) with T(c)=18 and 25 K. Unlike the hole-doped (p-type) SC cuprates, where incommensurate magnetic fluctuations commonly exist, the n-type cuprate shows commensurate magnetic fluctuations at the tetragonal (1/2 1/2 0) reciprocal points both in the SC and in the normal state. A spin gap opens up when the n-type cuprate becomes SC, as in the optimally doped p-type La2-xSrxCuO4. The gap energy, however, increases gradually up to about 4 meV as T decreases from T(c) to 2 K, which contrasts with the spin pseudogap behavior with a T-independent gap energy in the SC state of p-type cuprates. 相似文献
754.
755.
The piston-driven ultra rapid pressure swing adsorption (URPSA) equipment was developed and oxygen enrichment from air was examined as an example. The adsorbent bed is directly connected to the cylinder where a piston moves at high frequency. Thus pressurization and depressurization in the bed are driven by mechanical piston motion, which can achieve far more rapid cycles compared with the conventional pressure swing operation using valves. The cycle time is usually on the order of seconds or sub seconds. Oxygen enrichment from air up to about 60% or higher of oxygen concentration was achieved by small-scale equipment using zeolite 5A with a oxygen production capacity of 100 Nm3-product gas/m3-zeolite/hr, which is about ten times larger than those of commercialized PSAs for this purpose.A simplified numerical model describing the mass transfer taking place in URPSA was developed. The model could simulate fairly well the air separation characteristics in terms of oxygen concentration, oxygen production capacity and oxygen yield. The proposed model helps in the understanding of the basic nature of URPSA and possible applications. This novel PSA is promising as a compact yet high-capacity PSA to be utilized in a wide variety of applications. 相似文献
756.
H Oyama M Endoh M Yoneda M Matsuki A Satoh S Nishida M Horino 《Journal of chromatography. A》1985,338(1):71-78
A successful application of high-performance liquid chromatography for analysis of urinary C-peptide is described. Samples (1.0 ml of human urine) were first subjected to gel chromatography to remove interfering substances, and then applied to a reversed-phase column (LiChrosorb RP-18, 7 micron). The detection of C-peptide was performed using a highly specific radioimmunoassay. With the newly developed techniques, at least four forms of immunoreactive C-peptide were detected in human urine. One of these peptides was indistinguishable from authentic C-peptide. The present study has clearly demonstrated the heterogeneity of urinary C-peptide. 相似文献
757.
The magnetic phase transition of the amorphous ferromagnetic alloys Fe80P13C7, Fe70Cr10P13C7 and Fe70Ni10P13C7 has been investigated by magnetization and specific heat measurements. From the field dependence of the isothermal magnetization, the critical exponents and the Curie temperature (TC) of Fe80P13C7 were obtained to be β = 0.38 ± 0.02, γ = 1.30 ± 0.05, θ = 4.47 ± 0.05 and Tc = 586.55 ± 0.1°K. These exponents sufficiently satisfy the static scaling law. The specific heat of Fe80P13C7 showed an approximate logarithmic singularity at Tc. The specific heat from Fe70Ni10P13C7 shows fairly broad peak and the peak almost smears out for Fe70Cr10P13C7. 相似文献
758.
Sound localization can be controlled by using head related transfer functions (HRTFs), which are related to the size of the head, the ears and so on. Since HRTFs are characterized by source directions and subjects, it is necessary to conduct measurements in all directions for all subjects. However, such measurement is expensive and time-consuming. In this paper, we propose a simpler and more useful method that investigates the relationship between HRTFs and physical size by multiple regression analysis. The estimated HRTFs are evaluated by objective and subjective measures. For objective results, the average spectral distortion score is 4.0 dB in a bandwidth ranging from 0 to 8 kHz. Subjective results indicate no significant difference between the measured and the estimated HRTFs in that frequency range. These results support the hypothesis that the proposed method is effective for estimating HRTFs. 相似文献
759.
A polarimetric imaging method of a 3D object by use of on-axis phase-shifting digital holography is presented. The polarimetric image results from a combination of two kinds of holographic imaging using orthogonal polarized reference waves. Experimental demonstration of a 3D polarimetric imaging is presented. 相似文献
760.
Takanori Suzuki Ryuuichi Tamaki Eisuke Ohta Takashi Takeda Hidetoshi Kawai Kenshu Fujiwara Masako Kato 《Tetrahedron letters》2007,48(22):3823-3827
The spiro-acridan/acridinium-based dynamic redox pair (1/22+) transduces the electrochemical input into UV-vis and fluorescence spectra, whereas the 2,2′-bipyridine units in 1 works as a bidentate ligand for metal ions. X-ray structural analyses of this redox pair and the corresponding Zn-complexes [1-ZnI2/22+-Zn2+(OTf−)4] demonstrate drastic structural changes upon electron-transfer, thus metal binding properties are modified by redox reactions. 相似文献