Hard X-ray Imager(HXI)is one of the three scientific instruments onboard the Advanced Spacebased Solar Observatory(ASO-S)mission,which is proposed for the 25th solar maximum by the Chinese solar community.HXI is desig...Hard X-ray Imager(HXI)is one of the three scientific instruments onboard the Advanced Spacebased Solar Observatory(ASO-S)mission,which is proposed for the 25th solar maximum by the Chinese solar community.HXI is designed to investigate the non-thermal high-energy electrons accelerated in solar flares by providing images of solar flaring regions in the energy range from 30 keV to 200 keV.The imaging principle of HXI is based on spatially modulated Fourier synthesis and utilizes about 91 sets of bi-grid sub-collimators and corresponding LaBr3 detectors to obtain Fourier components with a spatial resolution of about 3 arcsec and a time resolution better than 0.5 s.An engineering prototype has been developed and tested to verify the feasibility of design.In this paper,we present background,instrument design and the development and test status of the prototype.展开更多
Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadoli...Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadolinium oxy-sulfide (GOS) fluorescent screen and a Cannon 500D digital camera were designed and constructed for real-time and near real-time x-ray imaging. The camera was connected to a laptop computer via USB port to allow remote camera setting and control as well as view image on the computer. The system was tested with x-rays generated from a Rigaku x-ray tube for its response at various camera settings and exposure times. The image brightness increased with increasing of the camera ISO setting and with the exposure time as expected. To test the system performance, two test specimens were radiographed including a video camera and a floppy disk drive as well as two simulated specimens. Each of the test specimens was also radiographed at two positions by moving the specimens approximately 6 cm from the first position. The two radiographs of each specimen were then combined to make an anaglyph image that could be viewed in 3D on a normal LCD or LED monitor by using appropriate color glasses. When the two radiographs were combined to make MPO (multiple object) file format, it could be viewed in 3D on a 3D monitor with or without 3D glasses depending on type of the monitor. The developed system could be conveniently employed for routine inspection of a specimen both in 2D and 3D within a minute.展开更多
The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic fie...The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic field,solar flares and coronal mass ejections(CMEs).Three payloads are deployed:the Full-disk vector Magneto Graph(FMG),the Lyman-αSolar Telescope(LST)and the Hard X-ray Imager(HXI).ASO-S will perform the first simultaneous observations of the photospheric vector magnetic field,non-thermal imaging of solar flares,and the initiation and early propagation of CMEs on a single platform.ASO-S is scheduled to be launched into a 720 km Sun-synchronous orbit in 2022.This paper presents an overview of the mission till the end of Phase-B and the beginning of Phase-C.展开更多
The Advanced Space-based Solar Observatory(ASO-S)is the first approved solar space mission in China.This special issue includes a total of 13 papers,which were selected from presentations at the First ASO-S Internatio...The Advanced Space-based Solar Observatory(ASO-S)is the first approved solar space mission in China.This special issue includes a total of 13 papers,which were selected from presentations at the First ASO-S International Workshop,held in Nanjing from 2019 January 15 to 18.Taken together,these 13 papers provide a complete description of ASO-S until the end of Phase-B and the beginning of Phase-C.展开更多
Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staf...Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staff at risk of radiation-induced injury. Radiation dose to patients during ERCP depends on many factors, and the endoscopist cannot control some variables, such as patient size, procedure type, or fluoroscopic equipment used. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. When fluoroscopy is used to assist ERCP, the shortest fluoroscopy time possible is recommended. Pulsed fluoroscopy and monitoring the length of fluoroscopy have been suggested for an overall reduction in both radiation exposure and fluoroscopy times. Fluoroscopy time is shorter when ERCP is performed by an endoscopist who has many years experience of performing ERCP and carried out a large number of ERCPs in the preceding year. In general, radiation exposure is greater during therapeutic ERCP than during diagnostic ERCP. Factors associated with prolonged fluoroscopy have been delineated recently, but these have not been validated.展开更多
Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral ...Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral or hybrid approaches can reduce infection rates and recovery time as well as shorten hospital stays.Minimally invasive approaches therefore are the trend and often the preferred choice,and may even be the only option for the patients associated with high surgery risks.Common interventional imaging modalities include 2-D X-ray fluoroscopy and ultrasound.However,fluoroscopic images do not display the anatomic structures without a contrast agent,which on the other hand,needs to be minimized for patients' safety.Ultrasound images suffer from relatively low image quality and tissue contrast problems.To augment the doctor's view of the patient's anatomy and help doctors navigate the devices to the targeted area with more confidence and a higher accuracy,high-resolution pre-operative volumetric data such as computed tomography and/or magnetic resonance can be fused with intra-operative 2-D images during interventions.A seamless workflow and accurate 2-D/3-D registrationas well as cardiac and/or respiratory motion compensation are the key components for a successful image guidance system using a patient-specific 3-D model.Dr.Liao's research has been focused on developing methods and systems of 3-D model guidance for various interventions and hybrid-OR applications.Dr.Liao' s work has led to several Siemens products with high clinical and/or market impact and a good number of scientific publications in leading journals/conferences on medical imaging.展开更多
Purpose We present the five-year in-orbit background evolution of Insight-HXMT since the launch,as well as the effects of the background model in data analysis.Methods The backgrounds of the three main payloads,i.e.,l...Purpose We present the five-year in-orbit background evolution of Insight-HXMT since the launch,as well as the effects of the background model in data analysis.Methods The backgrounds of the three main payloads,i.e.,low-energy telescope,medium-energy telescope,and high-energy telescope,are described.The evolution of the background over time is obtained by simply comparing the background in every year during the in-orbit operation of Insight-HXMT.Results The major observational characteristics of the Insight-HXMT in-orbit background are presented,including the light curve,spectrum,geographical distribution,and long-term evolution.The systematic error in background estimation is investigated for every year.Conclusion The observational characteristics of the five-year in-orbit background are consistent with our knowledge of the satellite design and the space environment,and the background model is still valid for the latest observations of Insight-HXMT.展开更多
基金supported by the Strategic Priority Research Program on Space Science, Chinese Academy of Sciences (Grant No. XDA15320104)the National Natural Science Foundation of China (Grant Nos. 11427803, 11622327, 11703079, 11803093 and 11820101002)
文摘Hard X-ray Imager(HXI)is one of the three scientific instruments onboard the Advanced Spacebased Solar Observatory(ASO-S)mission,which is proposed for the 25th solar maximum by the Chinese solar community.HXI is designed to investigate the non-thermal high-energy electrons accelerated in solar flares by providing images of solar flaring regions in the energy range from 30 keV to 200 keV.The imaging principle of HXI is based on spatially modulated Fourier synthesis and utilizes about 91 sets of bi-grid sub-collimators and corresponding LaBr3 detectors to obtain Fourier components with a spatial resolution of about 3 arcsec and a time resolution better than 0.5 s.An engineering prototype has been developed and tested to verify the feasibility of design.In this paper,we present background,instrument design and the development and test status of the prototype.
文摘Conventional x-ray stereoradiography based on film radiography is not practical due to its inconvenient and time-consuming procedures. In this research, an image viewing system consisted of a 30 cm × 30 cm gadolinium oxy-sulfide (GOS) fluorescent screen and a Cannon 500D digital camera were designed and constructed for real-time and near real-time x-ray imaging. The camera was connected to a laptop computer via USB port to allow remote camera setting and control as well as view image on the computer. The system was tested with x-rays generated from a Rigaku x-ray tube for its response at various camera settings and exposure times. The image brightness increased with increasing of the camera ISO setting and with the exposure time as expected. To test the system performance, two test specimens were radiographed including a video camera and a floppy disk drive as well as two simulated specimens. Each of the test specimens was also radiographed at two positions by moving the specimens approximately 6 cm from the first position. The two radiographs of each specimen were then combined to make an anaglyph image that could be viewed in 3D on a normal LCD or LED monitor by using appropriate color glasses. When the two radiographs were combined to make MPO (multiple object) file format, it could be viewed in 3D on a 3D monitor with or without 3D glasses depending on type of the monitor. The developed system could be conveniently employed for routine inspection of a specimen both in 2D and 3D within a minute.
基金supported by the Strategic Priority Research Program on Space Science, Chinese Academy of Sciences (Grant Nos. XDA15320100, XDA15320102, XDA15320103, XDA15320104, XDA15320300 and XDA15052200)supported by the National Natural Science Foundation of China (Grant Nos. 11427803, U1731241, U1631242 and 11820101002)
文摘The Advanced Space-based Solar Observatory(ASO-S)is a mission proposed for the 25 th solar maximum by the Chinese solar community.The scientific objectives are to study the relationships between the solar magnetic field,solar flares and coronal mass ejections(CMEs).Three payloads are deployed:the Full-disk vector Magneto Graph(FMG),the Lyman-αSolar Telescope(LST)and the Hard X-ray Imager(HXI).ASO-S will perform the first simultaneous observations of the photospheric vector magnetic field,non-thermal imaging of solar flares,and the initiation and early propagation of CMEs on a single platform.ASO-S is scheduled to be launched into a 720 km Sun-synchronous orbit in 2022.This paper presents an overview of the mission till the end of Phase-B and the beginning of Phase-C.
文摘The Advanced Space-based Solar Observatory(ASO-S)is the first approved solar space mission in China.This special issue includes a total of 13 papers,which were selected from presentations at the First ASO-S International Workshop,held in Nanjing from 2019 January 15 to 18.Taken together,these 13 papers provide a complete description of ASO-S until the end of Phase-B and the beginning of Phase-C.
文摘Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staff at risk of radiation-induced injury. Radiation dose to patients during ERCP depends on many factors, and the endoscopist cannot control some variables, such as patient size, procedure type, or fluoroscopic equipment used. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. When fluoroscopy is used to assist ERCP, the shortest fluoroscopy time possible is recommended. Pulsed fluoroscopy and monitoring the length of fluoroscopy have been suggested for an overall reduction in both radiation exposure and fluoroscopy times. Fluoroscopy time is shorter when ERCP is performed by an endoscopist who has many years experience of performing ERCP and carried out a large number of ERCPs in the preceding year. In general, radiation exposure is greater during therapeutic ERCP than during diagnostic ERCP. Factors associated with prolonged fluoroscopy have been delineated recently, but these have not been validated.
文摘Compared to surgery,interventional and hybrid-operating-room(OR) approaches diagnose or treat pathology with the most minimally invasive techniques possible.By minimizing the physical trauma to the patient,peripheral or hybrid approaches can reduce infection rates and recovery time as well as shorten hospital stays.Minimally invasive approaches therefore are the trend and often the preferred choice,and may even be the only option for the patients associated with high surgery risks.Common interventional imaging modalities include 2-D X-ray fluoroscopy and ultrasound.However,fluoroscopic images do not display the anatomic structures without a contrast agent,which on the other hand,needs to be minimized for patients' safety.Ultrasound images suffer from relatively low image quality and tissue contrast problems.To augment the doctor's view of the patient's anatomy and help doctors navigate the devices to the targeted area with more confidence and a higher accuracy,high-resolution pre-operative volumetric data such as computed tomography and/or magnetic resonance can be fused with intra-operative 2-D images during interventions.A seamless workflow and accurate 2-D/3-D registrationas well as cardiac and/or respiratory motion compensation are the key components for a successful image guidance system using a patient-specific 3-D model.Dr.Liao's research has been focused on developing methods and systems of 3-D model guidance for various interventions and hybrid-OR applications.Dr.Liao' s work has led to several Siemens products with high clinical and/or market impact and a good number of scientific publications in leading journals/conferences on medical imaging.
基金supports from the National Key R&D Program of China(2021YFA0718500)the National Natural Science Foundation of China under Grants Nos.U1838202 and U1838201This work was partially supported by International Partnership Program of Chinese Academy of Sciences(Grant No.113111KYSB20190020).
文摘Purpose We present the five-year in-orbit background evolution of Insight-HXMT since the launch,as well as the effects of the background model in data analysis.Methods The backgrounds of the three main payloads,i.e.,low-energy telescope,medium-energy telescope,and high-energy telescope,are described.The evolution of the background over time is obtained by simply comparing the background in every year during the in-orbit operation of Insight-HXMT.Results The major observational characteristics of the Insight-HXMT in-orbit background are presented,including the light curve,spectrum,geographical distribution,and long-term evolution.The systematic error in background estimation is investigated for every year.Conclusion The observational characteristics of the five-year in-orbit background are consistent with our knowledge of the satellite design and the space environment,and the background model is still valid for the latest observations of Insight-HXMT.
