Photodissociation of HOBr is an important step in the reaction network of the depletion of ozone in stratosphere.Here,we report the first three-dimensional potential energy surfaces for the lowest three singlet states...Photodissociation of HOBr is an important step in the reaction network of the depletion of ozone in stratosphere.Here,we report the first three-dimensional potential energy surfaces for the lowest three singlet states for HOBr,based on high level multi reference configuration interaction calculations.Quantum dynamics calculations are performed with a real wavepacket method,yielding not only absorption spectra but also internal state and angular distributions of the photodissociation fragments.Our results agree quantitatively with the measured total absorption cross sections of HOBr in the ultraviolet region and reproduce well the observed vibrationally cold and rotationally hot OH/OD fragments via photodissociation of HOBr/DOBr at 266 nm.In addition,we predict that the recoil anisotropy parameters for OH/OD are close to the limiting value of a parallel transition,suggesting a rapid dissociation process at 266 nm following an in-plane transition from the ground state(1^1A')to the 21A'state.This is consistent with the experimental conclusion derived from the measured rotational alignment.However,spin and electronic angular momenta need to be taken into account in the future to achieve a more quantitative agreement with experiment.Our work is expected to motivate further experimental investigations for this benchmark system.展开更多
This work is focused on the characterization and rapid analytical determination of cereal flour quality with regard to nutritional and breadmaking quality. Starch, protein and non-starch polysaccharides are the main c...This work is focused on the characterization and rapid analytical determination of cereal flour quality with regard to nutritional and breadmaking quality. Starch, protein and non-starch polysaccharides are the main components of cereals. The content and quality of proteins and content of damaged starch is important because of the technological quality of flours. The high content of high molecular weight proteins is substantial for bread technology especially, while soluble protein fractions and non-starch polysaccharides are important for nutrition. The set of wheat, barley and rye flours and their blends were analyzed and their properties and their qualitative parameters were determined. Principal component analysis （PCA） was used on Fourier transform-infrared （FT-IR） spectra in the 1,200-800 cm1 wavenumber region and significant correlations of various nutritional and breadmaking parameters were observed. Results showed that the FT-IR spectroscopy and PCA can serve for rapid screening and classification of cereal flour quality.展开更多
The high-performance CPC-trough （compound parabolic concentrator） collector has been developed for the utility scale generation of low temperature solar steam and hot water for low temperature process heat applicati...The high-performance CPC-trough （compound parabolic concentrator） collector has been developed for the utility scale generation of low temperature solar steam and hot water for low temperature process heat applications including solar air conditioning. With an optical concentration of 7.5：1, operating temperatures over 130 ℃ may be reached. This novel design has included a FEM （finite element modeling） validation and is compatible with the standard reflectors and evacuated tubes in the market. The peak efficiencies of 35% with unshielded and more than 45% with evacuated tube receivers were obtained. This CPC-trough collector requires intermittent tracking, i.e., tilt adjustment is only once in a week for more than eight hours collection in summer and six to seven hours in winter seasons.展开更多
基金supported by the National Key R&D Program of China (2017YFA0303500)Anhui Initiative in Quantum Information Technologies(AHY090200).
文摘Photodissociation of HOBr is an important step in the reaction network of the depletion of ozone in stratosphere.Here,we report the first three-dimensional potential energy surfaces for the lowest three singlet states for HOBr,based on high level multi reference configuration interaction calculations.Quantum dynamics calculations are performed with a real wavepacket method,yielding not only absorption spectra but also internal state and angular distributions of the photodissociation fragments.Our results agree quantitatively with the measured total absorption cross sections of HOBr in the ultraviolet region and reproduce well the observed vibrationally cold and rotationally hot OH/OD fragments via photodissociation of HOBr/DOBr at 266 nm.In addition,we predict that the recoil anisotropy parameters for OH/OD are close to the limiting value of a parallel transition,suggesting a rapid dissociation process at 266 nm following an in-plane transition from the ground state(1^1A')to the 21A'state.This is consistent with the experimental conclusion derived from the measured rotational alignment.However,spin and electronic angular momenta need to be taken into account in the future to achieve a more quantitative agreement with experiment.Our work is expected to motivate further experimental investigations for this benchmark system.
文摘This work is focused on the characterization and rapid analytical determination of cereal flour quality with regard to nutritional and breadmaking quality. Starch, protein and non-starch polysaccharides are the main components of cereals. The content and quality of proteins and content of damaged starch is important because of the technological quality of flours. The high content of high molecular weight proteins is substantial for bread technology especially, while soluble protein fractions and non-starch polysaccharides are important for nutrition. The set of wheat, barley and rye flours and their blends were analyzed and their properties and their qualitative parameters were determined. Principal component analysis （PCA） was used on Fourier transform-infrared （FT-IR） spectra in the 1,200-800 cm1 wavenumber region and significant correlations of various nutritional and breadmaking parameters were observed. Results showed that the FT-IR spectroscopy and PCA can serve for rapid screening and classification of cereal flour quality.
文摘The high-performance CPC-trough （compound parabolic concentrator） collector has been developed for the utility scale generation of low temperature solar steam and hot water for low temperature process heat applications including solar air conditioning. With an optical concentration of 7.5：1, operating temperatures over 130 ℃ may be reached. This novel design has included a FEM （finite element modeling） validation and is compatible with the standard reflectors and evacuated tubes in the market. The peak efficiencies of 35% with unshielded and more than 45% with evacuated tube receivers were obtained. This CPC-trough collector requires intermittent tracking, i.e., tilt adjustment is only once in a week for more than eight hours collection in summer and six to seven hours in winter seasons.
