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31.
Sintering behavior and bioactivity of diopside, CaMgSi2O6, prepared by a coprecipitation process were examined for its biomedical applicability. As-prepared powder was synthesized by adding aqueous ammonia to an ethanol solution containing Ca(NO3)2·4H2O, Mg(NO3)2·6H2O, and Si(OC2H5)4 and characterized by means of TG–DTA, XRD, and TG–MS. The dried powder was X-ray amorphous and crystallized into diopside at 845.5 °C. The glass network formation by SiO4 tetrahedra was almost completed below 800 °C. The bioactivity of the diopside prepared by sintering the compressed powder at 1100 °C for 2 h was evaluated by immersion of the sintered body in a simulated body fluid (SBF) at 36.5 °C. Leaf-like apatite particles were found to be formed on the surface of the sintered body and grew with passage of soaking time. This apatite-forming behavior in the SBF is related to the dissolution of Ca(II) ions from the sintered body in the early stage of immersion. Thus, diopside prepared by the coprecipitation process using the metal alkoxide and the metal salts was found to have an apatite-forming ability. 相似文献
32.
To deduce the optical properties, the absorption coefficient SmUaand reduced scattering coefficient μ’s, of turbid medium, Lin et al. (Appl. Opt. 34 (1995) 2362) proposed an oblique incidence reflectometry in which the diffusion approximation was assumed. In this paper we propose an alternative method which does not assume the diffusion approximation but uses a Monte Carlo light propagation model. Two features are extracted from the diffuse reflectance distribution detected on the medium surface, and optical properties are then estimated by looking up the predetermined table generated by Monte Carlo simulations. The validity of the proposed method has been confirmed by computer simulations. 相似文献
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Fast Estimation Algorithm for Calculation of Reflectance Map based on Wiener Estimation Technique 总被引:1,自引:0,他引:1
We propose a fast estimation algorithm for calculation of a reflectance map from measured radiances based on Wiener estimation technique. This technique uses many sample data of reflectance maps to decide transformation for accurate estimation. Reflectance maps of objects are estimated rapidly by linear operation between a vector of measured radiances and an estimation matrix previously calculated based on the sample data. 相似文献
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O'Driscoll P Minogue N Takenaka N Sodeau J 《The journal of physical chemistry. A》2008,112(8):1677-1682
The known room-temperature, solution-phase reaction between nitrite ions and iodide ions, which occurs in acidic conditions (pH < 5.5), is shown to be accelerated when neutral aqueous solutions are frozen. The reaction is proposed to occur in liquid "micropockets" within the ice structure at temperatures between the freezing point and the eutectic temperature. The products, nitric oxide and molecular iodine, are known to play significant roles in atmospheric compositional change, and therefore, the results obtained here, which are not dependent on acidification, may impact on observed snowpack chemistry. Investigation of the effect of oxygen on the chemical processing indicates that a chain reaction mechanism is operative. 相似文献
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We study Brezis-Nirenberg type theorems for the equation
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Kugimoto Toshimitsu Yamamoto Shoji Domon Ryota Hikosaka Kentaro Tsumura Norimichi 《Optical Review》2016,23(3):549-558
Optical Review - In this paper, we consider the use of an environment map as a photographic support tool for understanding the condition of surrounding light. It is well known that an environment... 相似文献
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Takumi Nakanishi Yuta Hori Shuqi Wu Hiroyasu Sato Atsushi Okazawa Prof. Norimichi Kojima Yusuke Horie Hajime Okajima Prof. Akira Sakamoto Yoshihito Shiota Prof. Kazunari Yoshizawa Prof. Osamu Sato 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(35):14891-14897
A proton–electron coupling system, exhibiting unique bistability or multistability of the protonated state, is an attractive target for developing new switchable materials based on proton dynamics. Herein, we present an iron(II) hydrazone crystalline compound, which displays the stepwise transition and bistability of proton transfer at the crystal level. These phenomena are realized through the coupling with spin transition. Although the multi-step transition with hysteresis has been observed in various systems, the corresponding behavior of proton transfer has not been reported in crystalline systems; thus, the described iron(II) complex is the first example. Furthermore, because proton transfer occurs only in one of the two ligands and π electrons redistribute in it, the dipole moment of the iron(II) complexes changes with the proton transfer, wherein the total dipole moment in the crystal was canceled out owing to the antiferroelectric-like arrangement. 相似文献