The performance of CdZnTe X/γ-ray detectors is strongly affected by the electric field distribution in terms of charge transport and charge collection.Factors which determine the electric field distribution are not o...The performance of CdZnTe X/γ-ray detectors is strongly affected by the electric field distribution in terms of charge transport and charge collection.Factors which determine the electric field distribution are not only electric contact,but also intrinsic defects,especially grown-in twin boundaries.Here,the electric field distribution around twin boundaries is investigated in a CdZnTe bicrystal detector with a{111}–{111}twin plane using the Pockels electro-optic effect.The results of laser beam induced current pulses are also obtained by the transient current technique,and we discuss the influence of the twin boundary on the electric field evolution.These studies reveal a significant distortion of the electric field,which is attributed to the buildup of space charges at twin boundaries.Also,the position of these space charge regions depends on the polarity of the detector bias.An energy band model based on the formation of an n–n+–n junction across the twin boundary has been established to explain the observed results.展开更多
Light field imaging is an emerging technology in computational photography areas. Based on innovative designs of the imaging model and the optical path, light field cameras not only record the spatial intensity of thr...Light field imaging is an emerging technology in computational photography areas. Based on innovative designs of the imaging model and the optical path, light field cameras not only record the spatial intensity of three- dimensional （3D） objects, but also capture the angular information of the physical world, which provides new ways to address various problems in computer vision, such as 3D reconstruction, saliency detection, and object recognition. In this paper, three key aspects of light field cameras, i.e., model, calibration, and reconstruction, are reviewed extensively. Furthermore, light field based applications on informatics, physics, medicine, and biology are exhibited. Finally, open issues in light field imaging and long-term application prospects in other natural sciences are discussed.展开更多
Six sesquiterpenes, including three guaiane type sesquiterpenes （1-3）, one oplopanone type sesquiterpene （4）, one xanthane type sesquiterpene （5） and one salvialane type sesquiterpene （6）, were isolated from A...Six sesquiterpenes, including three guaiane type sesquiterpenes （1-3）, one oplopanone type sesquiterpene （4）, one xanthane type sesquiterpene （5） and one salvialane type sesquiterpene （6）, were isolated from Alisma plantago-aquatica for the first time. The structures of these six compounds were elucidated as alismoxide （1）, alismol （2）, orientalol B （3）, oplopanone （4）, gibberodione （5）, and 7a, lOa-epoxy-salvialan-1Ofl-ol （6）, respectively, among which 6 was a new natural product. Xanthane type and salvialane type sesquiterpenes were obtained from the genus Alisma for the first time. In addition, a plausible biosynthetic pathway for all isolates was discussed.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1631116 and 51702271)the National Key Research and Development Program of China(Grant No.2016YFE0115200)+3 种基金the Natural Science Basic Research Plan in Shaanxi Province of China(Grant No.2017KW-029)Austrian Academic Exchange Service(ÖD-WTZ)through project CN 02/2016the Fundamental Research Funds for the Central Universities of China(Grant Nos.3102017zy057 and 3102018jcc036)the Young and Middle-aged Teachers Education and Scientific Research Foundation of Fujian Province,China(Grant No.JAT170407)
文摘The performance of CdZnTe X/γ-ray detectors is strongly affected by the electric field distribution in terms of charge transport and charge collection.Factors which determine the electric field distribution are not only electric contact,but also intrinsic defects,especially grown-in twin boundaries.Here,the electric field distribution around twin boundaries is investigated in a CdZnTe bicrystal detector with a{111}–{111}twin plane using the Pockels electro-optic effect.The results of laser beam induced current pulses are also obtained by the transient current technique,and we discuss the influence of the twin boundary on the electric field evolution.These studies reveal a significant distortion of the electric field,which is attributed to the buildup of space charges at twin boundaries.Also,the position of these space charge regions depends on the polarity of the detector bias.An energy band model based on the formation of an n–n+–n junction across the twin boundary has been established to explain the observed results.
基金Project supported by the National Natural Science Foundation of China （Nos. 61531014 and 61272287）
文摘Light field imaging is an emerging technology in computational photography areas. Based on innovative designs of the imaging model and the optical path, light field cameras not only record the spatial intensity of three- dimensional （3D） objects, but also capture the angular information of the physical world, which provides new ways to address various problems in computer vision, such as 3D reconstruction, saliency detection, and object recognition. In this paper, three key aspects of light field cameras, i.e., model, calibration, and reconstruction, are reviewed extensively. Furthermore, light field based applications on informatics, physics, medicine, and biology are exhibited. Finally, open issues in light field imaging and long-term application prospects in other natural sciences are discussed.
基金The National Science and Technology Major Project of“Technological study on the safety and standards of Chinese materia medica”(Grant No.2014ZX09304307-001-011)Chinese materia medica supporting program of“Quality control base construction of Chinese material medica including Isatidis Radix,Carthami Flos,etc”by Ministry of Industry and Information Technology of Peoples Republic of China
文摘Six sesquiterpenes, including three guaiane type sesquiterpenes （1-3）, one oplopanone type sesquiterpene （4）, one xanthane type sesquiterpene （5） and one salvialane type sesquiterpene （6）, were isolated from Alisma plantago-aquatica for the first time. The structures of these six compounds were elucidated as alismoxide （1）, alismol （2）, orientalol B （3）, oplopanone （4）, gibberodione （5）, and 7a, lOa-epoxy-salvialan-1Ofl-ol （6）, respectively, among which 6 was a new natural product. Xanthane type and salvialane type sesquiterpenes were obtained from the genus Alisma for the first time. In addition, a plausible biosynthetic pathway for all isolates was discussed.
