A new dihydrochromone derivative, named chaenomone, was isolated from the twigs of Chaenomeles sinensis (Thouin) Koehne. The structure was determined by spectroscopic methods.
Dear Editor,In recent years,owing to the fact that antibiotic-resistant bacteria have become more and more prevalent,there has been a resurgence of interest in the use of bacteriophages.However,bacteriophage therapy r...Dear Editor,In recent years,owing to the fact that antibiotic-resistant bacteria have become more and more prevalent,there has been a resurgence of interest in the use of bacteriophages.However,bacteriophage therapy remains an underutilized option in modern medicine due to technical hurdles such as limited host range,narrow spectrum of bacteria展开更多
The fuzzy linear regression forecasting model is deduced from the symmetric triangular fuzzy number. With the help of the degree of fitting and the measure of fuzziness, the determination of symmetric triangular fuzzy...The fuzzy linear regression forecasting model is deduced from the symmetric triangular fuzzy number. With the help of the degree of fitting and the measure of fuzziness, the determination of symmetric triangular fuzzy numbers is changed into a problem of solving linear programming.展开更多
We present a study of the β Cephei instability strip based on a sample of 49 stars of this type. After deriving their effective temperatures and luminosities from their observed (B - V), (U - B) colors and parallaxes...We present a study of the β Cephei instability strip based on a sample of 49 stars of this type. After deriving their effective temperatures and luminosities from their observed (B - V), (U - B) colors and parallaxes we find their positions in the HR diagram to be mostly confined to the main sequence, and their masses to lie between 7 M⊙ and 30 M⊙ . Their distribution on the HR diagram matches well with our previous theoretical instability strip which has an upper bound in the luminosity and rather tight boundaries in the effective temperature.展开更多
文摘A new dihydrochromone derivative, named chaenomone, was isolated from the twigs of Chaenomeles sinensis (Thouin) Koehne. The structure was determined by spectroscopic methods.
基金supported by the Natural Science Foundation of China(30571637)
文摘Dear Editor,In recent years,owing to the fact that antibiotic-resistant bacteria have become more and more prevalent,there has been a resurgence of interest in the use of bacteriophages.However,bacteriophage therapy remains an underutilized option in modern medicine due to technical hurdles such as limited host range,narrow spectrum of bacteria
文摘The fuzzy linear regression forecasting model is deduced from the symmetric triangular fuzzy number. With the help of the degree of fitting and the measure of fuzziness, the determination of symmetric triangular fuzzy numbers is changed into a problem of solving linear programming.
基金Supported by the National Natural Science Foundation of China.
文摘We present a study of the β Cephei instability strip based on a sample of 49 stars of this type. After deriving their effective temperatures and luminosities from their observed (B - V), (U - B) colors and parallaxes we find their positions in the HR diagram to be mostly confined to the main sequence, and their masses to lie between 7 M⊙ and 30 M⊙ . Their distribution on the HR diagram matches well with our previous theoretical instability strip which has an upper bound in the luminosity and rather tight boundaries in the effective temperature.
