Yanhua PANG
,
Wei FENG
,
Jie CHEN
,
Yan LIU
,
Weimin CAI
材料科学技术（英文）
A series of inorganic-organic thin films based on uniformly dispersed nanoparticles of polyoxometalates (POM) entrapped in polyacrylamide (PAM) matrix were prepared by ultrasonic method with different irradiation time. The microstructure, photochromic behavior and mechanism of the films were studied by transmission electron microscopy (TEM), ultraviolet-visible spectra (UV-VIS) and Fourier transform-infrared spectroscopy (FT-IR). The microstructure and photochromic properties of the hybrid thin films could be controlled by ultrasound. TEM image revealed that the average size of phosphotungstic acid (PWA) nanoparticles decreased from 20 to 10 nm with the ultrasound irradiation time from 30 to 60 min. After irradiated with ultraviolet light, the transparent films changed from colorless to blue and showed reversible photochromism. The hybrid film, with ultrasound irradiation for 60 min had higher photochromic efficiency and faster bleaching reaction than the one with ultrasound irradiation for 30 min. FT-IR spectra showed that the Keggin geometry of heteropolyoxometalate was still preserved inside the composites, and the interactions between polyanions and polymer matrix increased as the ultrasound time prolonged. It is suggested that the mechanism of the different photochromic properties for the inorganic-organic thin films is the variation of the microstructure and interfacial interactions induced by ultrasound.
关键词:
sonochemical
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Physics of Life Reviews
Commentaries by Philip W.T. Pong, Nongyue He, S.D. Liang, Tao Song, Yuri Gaididei and Sergey Volkov and Alexander Y. Grosberg on my review article (Pang, 2011 [1]) are answered. The validity of Davydov's mechanism of bio-energy transport, the completeness of theory, outstanding problems, the normalization and validity of wave function of the system in Pang' model as well as other related problems are elucidated in detail. (C) 2011 Elsevier B.V. All rights reserved.
关键词:
biological temperature;3 channels;soliton;model
Physica Status Solidi B-Basic Research
Contributions of magnon-phonon coupling and magnon-magnon interactions to the formation of localized solitons in common quasi-one-dimensional antiferromagnets are closely studied and discussed by using Makhankov's and Pang's method with double-sublattice model. The anomalous effect in the (CH3)4NMnCl3 system is also discussed by using these results.
关键词:
chains
Physics of Life Reviews
The bio-energy transport is a basic problem in life science and related to many biological processes. Therefore to establish the mechanism of bio-energy transport and its theory have an important significance. Based on different properties of structure of alpha-helical protein molecules some theories of bio-energy transport along the molecular chains have been proposed and established, where the energy is released by hydrolysis of adenosine triphosphate (ATP). A brief survey of past researches on different models and theories of bio-energy, including Davydov's, Takeno's, Yomosa's, Brown et al.'s, Schweitzer's, Cruzeiro-Hansson's, Forner's and Pang's models were first stated in this paper. Subsequently we studied and reviewed mainly and systematically the properties, thermal stability and lifetimes of the carriers (solitons) transporting the bio-energy at physiological temperature 300 K in Pang's and Davydov's theories. From these investigations we know that the carrier (soliton) of bio-energy transport in the alpha-helical protein molecules in Pang's model has a higher binding energy, higher thermal stability and larger lifetime at 300 K relative to those of Davydov's model, in which the lifetime of the new soliton at 300 K is enough large and belongs to the order of 10(-10) s or tau/tau(0) >= 700. Thus we can conclude that the soliton in Pang's model is exactly the carrier of the bio-energy transport, Pang's theory is appropriate to alpha-helical protein molecules. (C) 2011 Elsevier B.V. All rights reserved.
关键词:
Protein;Biological energy;Amide;Soliton;Quasi-coherent state;Lifetime;alpha-helix protein;davydov soliton dynamics;3 channels;infrared-absorption;finite-temperature;vibron solitons;improved;model;characteristic parameters;thermodynamic properties;crystalline;acetanilide
Journal of Applied Physics
The mechanism and properties of bio-photon emission and absorption in bio-tissues were studied using Pang's theory of bio-energy transport, in which the energy spectra of protein molecules are obtained from the discrete dynamic equation. From the energy spectra, it was determined that the protein molecules could both radiate and absorb bio-photons with wavelengths of <3 mu m and 5-7 mu m, consistent with the energy level transitions of the excitons. These results were consistent with the experimental data; this consisted of infrared absorption data from collagen, bovine serum albumin, the protein-like molecule acetanilide, plasma, and a person's finger, and the laser-Raman spectra of acidity I-type collagen in the lungs of a mouse, and metabolically active Escherichia coli. We further elucidated the mechanism responsible for the non-thermal biological effects produced by the infrared light absorbed by the bio-tissues, using the above results. No temperature rise was observed; instead, the absorbed infrared light promoted the vibrations of amides as well the transport of the bio-energy from one place to other in the protein molecules, which changed their conformations. These experimental results, therefore, not only confirmed the validity of the mechanism of bio-photon emission, and the newly developed theory of bio-energy transport mentioned above, but also explained the mechanism and properties of the non-thermal biological effects produced by the absorption of infrared light by the living systems. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4709420]
关键词:
alpha-helix protein;3 channels;davydov soliton;improved model;characteristic parameters;biological temperature;infrared-absorption;finite-temperature;raman-scattering;energy transport
