Stellar ranging is the basis for stellar dynamics research and in-depth research on astrophysics. The parallax method is the most widely used and important basic method for stellar ranging. However, it needs to perfor...Stellar ranging is the basis for stellar dynamics research and in-depth research on astrophysics. The parallax method is the most widely used and important basic method for stellar ranging. However, it needs to perform highprecision measurement of the parallax angle and the baseline length together. We aim to propose a new stellar ranging scheme based on second-order correlation that does not require a parallax angle measurement. We hope our solution can be as basic as the parallax method. We propose a new stellar ranging scheme by using the offset of second-order correlation curve signals. The optical path difference between the stars and different base stations is determined by the offset of the second-order correlation curve signals. Then the distance of the stars could be determined by the geometric relation. With the distance to stars out to 10 kpc away, our astrometric precision can be better compared to Gaia by simulation. We also design an experiment and successfully demonstrate the feasibility of this scheme. This stellar ranging scheme enables further and more accurate stellar ranging without requiring any prior information or angle measurement.展开更多
To the Editor:Acute kidney injury(AKI)is a common public health problem worldwide,which can adversely affect patients’quality of life and even lead to death.^([1])Academic hospitals play an important role in admittin...To the Editor:Acute kidney injury(AKI)is a common public health problem worldwide,which can adversely affect patients’quality of life and even lead to death.^([1])Academic hospitals play an important role in admitting and providing treatment for patients with AKI,but limited data exist regarding the characteristics of patients in county-level local hospitals.Our research group initiated a comprehensive survey as part of the International Society of Nephrology’s"0 by 25"project(eliminating all deaths related to untreated AKI by 2025)for investigating the disease burden of AKI and its associated risk factors and prognosis through 22 province-level regions of China in 2013.展开更多
基金supported by National Key Research and Development Program Earth Observation and Navigation Key Specialities (No. 2018YFB0504300)。
文摘Stellar ranging is the basis for stellar dynamics research and in-depth research on astrophysics. The parallax method is the most widely used and important basic method for stellar ranging. However, it needs to perform highprecision measurement of the parallax angle and the baseline length together. We aim to propose a new stellar ranging scheme based on second-order correlation that does not require a parallax angle measurement. We hope our solution can be as basic as the parallax method. We propose a new stellar ranging scheme by using the offset of second-order correlation curve signals. The optical path difference between the stars and different base stations is determined by the offset of the second-order correlation curve signals. Then the distance of the stars could be determined by the geometric relation. With the distance to stars out to 10 kpc away, our astrometric precision can be better compared to Gaia by simulation. We also design an experiment and successfully demonstrate the feasibility of this scheme. This stellar ranging scheme enables further and more accurate stellar ranging without requiring any prior information or angle measurement.
基金supported by grants from the National Natural Science Foundation of China(Nos.91742205,81625004,and 81860129)the Beijing Young Scientist Program(No.BJJWZYJH01201910001006)the Peking University Clinical Scientist Program by the Fundamental Research Funds for the Central Universities.
文摘To the Editor:Acute kidney injury(AKI)is a common public health problem worldwide,which can adversely affect patients’quality of life and even lead to death.^([1])Academic hospitals play an important role in admitting and providing treatment for patients with AKI,but limited data exist regarding the characteristics of patients in county-level local hospitals.Our research group initiated a comprehensive survey as part of the International Society of Nephrology’s"0 by 25"project(eliminating all deaths related to untreated AKI by 2025)for investigating the disease burden of AKI and its associated risk factors and prognosis through 22 province-level regions of China in 2013.
