Southeast Asia is located at the intersection of the Tethys and Pacific domains. The superimposed effects of the two tectonic domains have resulted in complicated deep structure, surface magma responses, and dynamic p...Southeast Asia is located at the intersection of the Tethys and Pacific domains. The superimposed effects of the two tectonic domains have resulted in complicated deep structure, surface magma responses, and dynamic processes of Southeast Asia. Based on the latest long-term passive seismic experiment and numerical modeling, this study reconstructs the dynamic processes of the closure of the Neo-Tethys Ocean and the formation of the curved subduction system in Southeast Asia since the Late Mesozoic. P-wave velocity structure shows a remnant of the Neo-Tethys subducted slab in the lower mantle beneath Southeast Asia at a depth of approximately 1500 km. On the Java-East Timor subduction zone, the remnant slab is coupled with the Indo-Australian subducting slab in the upper mantle with the same direction, while on the Sumatra subduction zone, the remnant slab is decoupled from the Indo-Australian subducting slab in different directions. The formation of the curved subduction system in Southeast Asia is resulted from the northward subdcutions of previous Neo-Tethys and current IndoAustralian Plate, and the westward subduction of the Pacific Plate since Mesozoic. The former is characterized by continuous subduction and subsequent continental block collision, forming the current continental lithosphere in Southeast Asia and the curve-shaped Sumatra-Java subduction zone;the latter is characterized by subduction retreat and back-arc spreading, forming the eastern Philippine subduction zone and a series of marginal sea basins. Since the Early Cretaceous, the opening of the North Australian Sea resulted in stagnation of the Australian Block in the high latitude area of the southern hemisphere for a long time.The North Australian Sea was dominated by out-dipping double subduction from 45 Ma, which resulted in rapid northward drifting of the Australian Block and final collision with the Sundaland.展开更多
Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image sensor.This results in a complex and bulk...Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image sensor.This results in a complex and bulky structure.In contrast,biological eyes possess a simple and compact structure due to their curved imaging structure that can directly match with the curved focal plane.Inspired by the structures and functions of biological eyes,curved vision systems not only improve the image quality,but also offer a variety of advanced functions.Here,we review the recent advances in bioinspired vision systems with curved imaging structures.Specifically,we focus on their applications in implementing different functions of biological eyes,as well as the emerging curved neuromorphic imaging systems that incorporate bioinspired optical and neuromorphic processing technologies.In addition,the challenges and opportunities of bioinspired curved imaging systems are also discussed.展开更多
The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.B...The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.展开更多
The conjugated polycycles show excellent optical and electrical properties that are suitable for application in various organic electronics.While most of attentions have been paid to polycycles having planar π-conjug...The conjugated polycycles show excellent optical and electrical properties that are suitable for application in various organic electronics.While most of attentions have been paid to polycycles having planar π-conjugated system,the curved polycycles seem amazing due to their unique physical and chemical features.The non-planar conjugated polycycles have been created with the geometries of bracelet,saddle,bowl,Mobius band,helicenes,etc.Among them,the bowl-shaped one is of growing interest owing to the multidiscipline applications such as synthetic intermediates for end-cap of carbon nanotube,coordination with metal ions,encapsulation of fullerenes,and fabrication of electronic devices.In this paper,we summarize the recent advances on the chemistry of the bowl-shaped conjugated polycycles,particularly on their synthesis and the further chemical modifications toward organic functional materials.展开更多
Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickne...Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickness micro radial and arcuate keratotomy incisions were constructed in porcine eyes with a femtosecond laser system and evaluated for precision of depth,quality,and consistency.Optical coherence tomography was used to determine the accuracy and precision of incision depth.Corneal endothelial safety was assessed by a fluorescent live/dead cell viability assay to demonstrate laser-induced endothelial cell loss.Quality was evaluated by ease of opening and examination of interfaces.Results:In two micro radial incision groups,intended incision depths of 50%and 80%resulted in mean achieved depths of 50.01%and 77.69%,respectively.In three arcuate incision groups,intended incision depths of 80%,600μm or 100μm residual uncut bed thickness resulted in mean achieved depths of 80.16%,603.03μm and residual bed of 115μm,respectively.No loss of endothelial cell density occurred when the residual corneal bed was maintained at a minimum of 85-116μm.The incisions were easy to open,and interfaces were smooth.Conclusions:A femtosecond laser system with curved contact interface created precise and reproducible micro radial and arcuate keratotomy incisions.Accuracy and precision of the incision depth and preservation of endothelial cell density demonstrated the effectiveness and safety of the system.展开更多
Recent advances on wheel-rail dynamic performance of curve negotiation are reviewed in this paper. There are four issues, the mechanism and calculation method of curve negotiation, the analysis and assessment of dynam...Recent advances on wheel-rail dynamic performance of curve negotiation are reviewed in this paper. There are four issues, the mechanism and calculation method of curve negotiation, the analysis and assessment of dynamic performance of vehicle, the effect of vehicle parameters on dynamic performance, and the influence of railway parameters on dynamic performance. The promising future development of wheel-rail coupled dynamics theory is analyzed in the research of curve negotiation. The framework and technique matching performance of wheel-rail dynamic interaction on the curved track are put forward for modem railways. In addition, the application of performance matching technique is introduced to the dynamic engineering, in which the wheel load is reduced obviously when the speed of train is raised to 200-250 km/h.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42025601,41890811&92155203)。
文摘Southeast Asia is located at the intersection of the Tethys and Pacific domains. The superimposed effects of the two tectonic domains have resulted in complicated deep structure, surface magma responses, and dynamic processes of Southeast Asia. Based on the latest long-term passive seismic experiment and numerical modeling, this study reconstructs the dynamic processes of the closure of the Neo-Tethys Ocean and the formation of the curved subduction system in Southeast Asia since the Late Mesozoic. P-wave velocity structure shows a remnant of the Neo-Tethys subducted slab in the lower mantle beneath Southeast Asia at a depth of approximately 1500 km. On the Java-East Timor subduction zone, the remnant slab is coupled with the Indo-Australian subducting slab in the upper mantle with the same direction, while on the Sumatra subduction zone, the remnant slab is decoupled from the Indo-Australian subducting slab in different directions. The formation of the curved subduction system in Southeast Asia is resulted from the northward subdcutions of previous Neo-Tethys and current IndoAustralian Plate, and the westward subduction of the Pacific Plate since Mesozoic. The former is characterized by continuous subduction and subsequent continental block collision, forming the current continental lithosphere in Southeast Asia and the curve-shaped Sumatra-Java subduction zone;the latter is characterized by subduction retreat and back-arc spreading, forming the eastern Philippine subduction zone and a series of marginal sea basins. Since the Early Cretaceous, the opening of the North Australian Sea resulted in stagnation of the Australian Block in the high latitude area of the southern hemisphere for a long time.The North Australian Sea was dominated by out-dipping double subduction from 45 Ma, which resulted in rapid northward drifting of the Australian Block and final collision with the Sundaland.
基金financially supported by the National Natural Science Foundation of China(Nos.52125205,U20A20166,61805015 and 61804011,52102184,52202181)the National key R&D program of China(Nos.2021YFB3200302 and 2021YFB3200304)the Fundamental Research Funds for the Central Universities。
文摘Limited by the planar imaging structure,the commercial camera needs to introduce additional optical elements to compensate for the curved focal plane to match the planar image sensor.This results in a complex and bulky structure.In contrast,biological eyes possess a simple and compact structure due to their curved imaging structure that can directly match with the curved focal plane.Inspired by the structures and functions of biological eyes,curved vision systems not only improve the image quality,but also offer a variety of advanced functions.Here,we review the recent advances in bioinspired vision systems with curved imaging structures.Specifically,we focus on their applications in implementing different functions of biological eyes,as well as the emerging curved neuromorphic imaging systems that incorporate bioinspired optical and neuromorphic processing technologies.In addition,the challenges and opportunities of bioinspired curved imaging systems are also discussed.
基金Support by the National Natural Science Foundation of China(No.92258303)the Project of Donghai Laboratory(No.DH-2022ZY0005)。
文摘The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works.
基金the National Natural Science Foundation of China(Nos.21522203,21372111,and 21190034)State Key Laboratory of Applied Organic Chemistry for the financial support
文摘The conjugated polycycles show excellent optical and electrical properties that are suitable for application in various organic electronics.While most of attentions have been paid to polycycles having planar π-conjugated system,the curved polycycles seem amazing due to their unique physical and chemical features.The non-planar conjugated polycycles have been created with the geometries of bracelet,saddle,bowl,Mobius band,helicenes,etc.Among them,the bowl-shaped one is of growing interest owing to the multidiscipline applications such as synthetic intermediates for end-cap of carbon nanotube,coordination with metal ions,encapsulation of fullerenes,and fabrication of electronic devices.In this paper,we summarize the recent advances on the chemistry of the bowl-shaped conjugated polycycles,particularly on their synthesis and the further chemical modifications toward organic functional materials.
文摘Background:To evaluate the accuracy and safety of micro radial and arcuate keratotomy incisions constructed by a femtosecond laser system with a curved contact patient interface in porcine eyes.Methods:Partial thickness micro radial and arcuate keratotomy incisions were constructed in porcine eyes with a femtosecond laser system and evaluated for precision of depth,quality,and consistency.Optical coherence tomography was used to determine the accuracy and precision of incision depth.Corneal endothelial safety was assessed by a fluorescent live/dead cell viability assay to demonstrate laser-induced endothelial cell loss.Quality was evaluated by ease of opening and examination of interfaces.Results:In two micro radial incision groups,intended incision depths of 50%and 80%resulted in mean achieved depths of 50.01%and 77.69%,respectively.In three arcuate incision groups,intended incision depths of 80%,600μm or 100μm residual uncut bed thickness resulted in mean achieved depths of 80.16%,603.03μm and residual bed of 115μm,respectively.No loss of endothelial cell density occurred when the residual corneal bed was maintained at a minimum of 85-116μm.The incisions were easy to open,and interfaces were smooth.Conclusions:A femtosecond laser system with curved contact interface created precise and reproducible micro radial and arcuate keratotomy incisions.Accuracy and precision of the incision depth and preservation of endothelial cell density demonstrated the effectiveness and safety of the system.
基金support and motivation provided by National Basic Research Programof China(973 Program No.2013CB036206)National Natural Science Foundation of China(No.61134002)
文摘Recent advances on wheel-rail dynamic performance of curve negotiation are reviewed in this paper. There are four issues, the mechanism and calculation method of curve negotiation, the analysis and assessment of dynamic performance of vehicle, the effect of vehicle parameters on dynamic performance, and the influence of railway parameters on dynamic performance. The promising future development of wheel-rail coupled dynamics theory is analyzed in the research of curve negotiation. The framework and technique matching performance of wheel-rail dynamic interaction on the curved track are put forward for modem railways. In addition, the application of performance matching technique is introduced to the dynamic engineering, in which the wheel load is reduced obviously when the speed of train is raised to 200-250 km/h.
