The ESR characteristics of boron-doped fullerene prepared by are vaporization of B2O3 powder and graphite in a helium ambient are investigated for the first time. It is found that the obtained ESR spectrum of boron-do...The ESR characteristics of boron-doped fullerene prepared by are vaporization of B2O3 powder and graphite in a helium ambient are investigated for the first time. It is found that the obtained ESR spectrum of boron-doped fullerene is attributed to two components with the same g value of around 2.0025.展开更多
a-Si:C:N:H thin films have been deposited at room temperature by r.f. reactive-sputtering of a Si target in an Ar+H-2+N-2+CH4 gas mixture. Fourier transform infrared-absorption spectroscopy and optical absorption spec...a-Si:C:N:H thin films have been deposited at room temperature by r.f. reactive-sputtering of a Si target in an Ar+H-2+N-2+CH4 gas mixture. Fourier transform infrared-absorption spectroscopy and optical absorption spectra have been investigated for the films. The study shows that the film structure and optical, electrical properties are obviously modified readily by controlling the process parameters of deposition. The nitrogen-rich a-Si:C:N:H films are thermally stable within the temperature ranging from 200 to 800 degrees C. They are of interest for the potential applications in electronic devices.展开更多
The estrogens show negative activity in Ames test, but estrodiol and diethylstilbestrol in estrogens both are carcinogens based upon animal experiments and epidemiological investigation. It is concluded from the di-re...The estrogens show negative activity in Ames test, but estrodiol and diethylstilbestrol in estrogens both are carcinogens based upon animal experiments and epidemiological investigation. It is concluded from the di-region theory, a mechanism conception put forward by one of the present authors, that the carcinogenesis of estrogens is switched on by the covalent cross-link between complementary DNA bases induced by them. We verified for the first time by the DNA alkaline elution method that both estrodiol and diethylstilbestrol cause covalent cross-link between DNA-protein and DNA interstrands after metabolic activation with dosage correlation, but neither the non-carcinogens cholesterol nor pyrene can lead to these sorts of cross-link in the same condition. It has been known that there is a synergetic effect between estrogen and pollution of polycyclic aromatic hydrocarbons. Although non-carcinogenic pyrene alone cannot induce cross-link, its addition with equal molar quantity to estrodiol culture展开更多
Adding various dopants during the growth of the parent KTiOPO4 (KTP) crystal has given rise to an extensive series of KTP-type crystals. The doped KTP or KTP-type crystals often have very subtle structural variations ...Adding various dopants during the growth of the parent KTiOPO4 (KTP) crystal has given rise to an extensive series of KTP-type crystals. The doped KTP or KTP-type crystals often have very subtle structural variations from pure KTP crystals. As a result of these structural changes the KTP-type crystals often exhibit different physical properties, which may be referred to as structure sensitive properties. It is possible to fine-tune the nonlinear optical properties of KTP crystals through doping. This results in a broad range of applications for KTP-type crystals.展开更多
KTiOPO-4(KTP) crystal is a nonlinear optical material with superior properties. The KTP structure, point group mm2, is typified by the chemical form {K++}〔Ti 4+〕O(P 5+)O-4, where the curly brackets indicate nine or ...KTiOPO-4(KTP) crystal is a nonlinear optical material with superior properties. The KTP structure, point group mm2, is typified by the chemical form {K++}〔Ti 4+〕O(P 5+)O-4, where the curly brackets indicate nine or eightfold coordination, the square brackets sixfold octahedral coordination and the parentheses fourfold tetrahedral coordination. Different isovalent and aliovalent substitutions in a given structure is quite interesting. The KTP-type structure is extremely accommodating with respect to partial or complete isomorphous substitution which may be especially significant in optical devices such as waveguides. A monographic review of the structure-property relationship of KTP isomorphous substitution is briefly and precisely presented. It is shown that the properties of KTP are very sensitive to its structure. Among the composition, structure and properties of KTP-type crystal, the structure is the core because it is a link between the composition and properties.展开更多
文摘The ESR characteristics of boron-doped fullerene prepared by are vaporization of B2O3 powder and graphite in a helium ambient are investigated for the first time. It is found that the obtained ESR spectrum of boron-doped fullerene is attributed to two components with the same g value of around 2.0025.
文摘a-Si:C:N:H thin films have been deposited at room temperature by r.f. reactive-sputtering of a Si target in an Ar+H-2+N-2+CH4 gas mixture. Fourier transform infrared-absorption spectroscopy and optical absorption spectra have been investigated for the films. The study shows that the film structure and optical, electrical properties are obviously modified readily by controlling the process parameters of deposition. The nitrogen-rich a-Si:C:N:H films are thermally stable within the temperature ranging from 200 to 800 degrees C. They are of interest for the potential applications in electronic devices.
文摘The estrogens show negative activity in Ames test, but estrodiol and diethylstilbestrol in estrogens both are carcinogens based upon animal experiments and epidemiological investigation. It is concluded from the di-region theory, a mechanism conception put forward by one of the present authors, that the carcinogenesis of estrogens is switched on by the covalent cross-link between complementary DNA bases induced by them. We verified for the first time by the DNA alkaline elution method that both estrodiol and diethylstilbestrol cause covalent cross-link between DNA-protein and DNA interstrands after metabolic activation with dosage correlation, but neither the non-carcinogens cholesterol nor pyrene can lead to these sorts of cross-link in the same condition. It has been known that there is a synergetic effect between estrogen and pollution of polycyclic aromatic hydrocarbons. Although non-carcinogenic pyrene alone cannot induce cross-link, its addition with equal molar quantity to estrodiol culture
基金This work was supported by the National Natural Science Foundation of China (Grant No. 59772001).
文摘Adding various dopants during the growth of the parent KTiOPO4 (KTP) crystal has given rise to an extensive series of KTP-type crystals. The doped KTP or KTP-type crystals often have very subtle structural variations from pure KTP crystals. As a result of these structural changes the KTP-type crystals often exhibit different physical properties, which may be referred to as structure sensitive properties. It is possible to fine-tune the nonlinear optical properties of KTP crystals through doping. This results in a broad range of applications for KTP-type crystals.
文摘KTiOPO-4(KTP) crystal is a nonlinear optical material with superior properties. The KTP structure, point group mm2, is typified by the chemical form {K++}〔Ti 4+〕O(P 5+)O-4, where the curly brackets indicate nine or eightfold coordination, the square brackets sixfold octahedral coordination and the parentheses fourfold tetrahedral coordination. Different isovalent and aliovalent substitutions in a given structure is quite interesting. The KTP-type structure is extremely accommodating with respect to partial or complete isomorphous substitution which may be especially significant in optical devices such as waveguides. A monographic review of the structure-property relationship of KTP isomorphous substitution is briefly and precisely presented. It is shown that the properties of KTP are very sensitive to its structure. Among the composition, structure and properties of KTP-type crystal, the structure is the core because it is a link between the composition and properties.
