The properties of Mach stems in hypersonic corner flow induced by Mach interaction over 3D intersecting wedges were studied theoretically and numerically.A new method called "spatial dimension reduction" was used to...The properties of Mach stems in hypersonic corner flow induced by Mach interaction over 3D intersecting wedges were studied theoretically and numerically.A new method called "spatial dimension reduction" was used to analyze theoretically the location and Mach number behind Mach stems. By using this approach, the problem of 3D steady shock/shock interaction over 3D intersecting wedges was transformed into a 2D moving one on cross sections, which can be solved by shock-polar theory and shock dynamics theory. The properties of Mach interaction over 3D intersecting wedges can be analyzed with the new method,including pressure, temperature, density in the vicinity of triple points, location, and Mach number behind Mach stems.Theoretical results were compared with numerical results,and good agreement was obtained. Also, the influence of Mach number and wedge angle on the properties of a 3D Mach stem was studied.展开更多
A new three-dimensional nickel(Ⅱ) hydrogen-bonded molecular self assembly containing [(Ni(nicotinamide)2(thiocyanate)2(H2O)2] complex has been synthesized and characterized by single-crystal X-ray diffractio...A new three-dimensional nickel(Ⅱ) hydrogen-bonded molecular self assembly containing [(Ni(nicotinamide)2(thiocyanate)2(H2O)2] complex has been synthesized and characterized by single-crystal X-ray diffraction,FTIR spectroscopy,thermal analysis and magnetic measurements.Structural analysis reveals that the complex crystallizes in triclinic space group P1(crystal data a = 7.5574,b = 8.2683,c = 9.0056 A,α = 73.010,β = 69.698,γ = 66.51) and exhibits a distorted octahedral coordination sphere.Most interesting point in its structure is the involvement of sulphur atom of thiocyanate moiety in the trifurcated hydrogen bonding to build up the hydrogen-bonded self assembly.The magnetic behavior as determined by squid magnetometer(2~300 K temp.range) reveals dominating antiferromagnetic interaction followed by spin canting behavior below 20 K.展开更多
Six degrees of freedom(6DoF)input interfaces are essential formanipulating virtual objects through translation or rotation in three-dimensional(3D)space.A traditional outside-in tracking controller requires the instal...Six degrees of freedom(6DoF)input interfaces are essential formanipulating virtual objects through translation or rotation in three-dimensional(3D)space.A traditional outside-in tracking controller requires the installation of expensive hardware in advance.While inside-out tracking controllers have been proposed,they often suffer from limitations such as interaction limited to the tracking range of the sensor(e.g.,a sensor on the head-mounted display(HMD))or the need for pose value modification to function as an input interface(e.g.,a sensor on the controller).This study investigates 6DoF pose estimation methods without restricting the tracking range,using a smartphone as a controller in augmented reality(AR)environments.Our approach involves proposing methods for estimating the initial pose of the controller and correcting the pose using an inside-out tracking approach.In addition,seven pose estimation algorithms were presented as candidates depending on the tracking range of the device sensor,the tracking method(e.g.,marker recognition,visual-inertial odometry(VIO)),and whether modification of the initial pose is necessary.Through two experiments(discrete and continuous data),the performance of the algorithms was evaluated.The results demonstrate enhanced final pose accuracy achieved by correcting the initial pose.Furthermore,the importance of selecting the tracking algorithm based on the tracking range of the devices and the actual input value of the 3D interaction was emphasized.展开更多
Based on light field reconstruction and motion recognition technique, a penetrable interactive floating 3D display system is proposed. The system consists of a high-frame-rate projector, a flat directional diffusing s...Based on light field reconstruction and motion recognition technique, a penetrable interactive floating 3D display system is proposed. The system consists of a high-frame-rate projector, a flat directional diffusing screen, a high-speed data transmission module, and a Kinect somatosensory device. The floating occlusioncorrect 3D image could rotate around some axis at different speeds according to user's hand motion. Eight motion directions and speed are detected accurately, and the prototype system operates efficiently with a recognition accuracy of 90% on average.展开更多
Subject Code:H06 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Zou Weiguo(邹卫国)from the Institute of Biochemistry and Cell Biology,Shanghai Institutes...Subject Code:H06 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Zou Weiguo(邹卫国)from the Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,CAS demonstrates that E3ligase SMURF2maintains bone展开更多
In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3+ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D as...In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3+ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D asynchronous spectrum confirms the occurrence of intermolecular interaction between Nd^3+and pyridinium.However,no coordination occurs between Nd^3+ and pyridinium.Interaction between πelectron from aromatic system and/electron from lanthanide ions account for the appearance of cross peaks in 2D asynchronous spectra.Because of the interaction,the emission spectrum of pyridinium exhibits a significant change when neodymium perchlorate was introduced into the system.展开更多
基金supported by the National Natural Science Foundation of China (Grants 11372333, 90916028)
文摘The properties of Mach stems in hypersonic corner flow induced by Mach interaction over 3D intersecting wedges were studied theoretically and numerically.A new method called "spatial dimension reduction" was used to analyze theoretically the location and Mach number behind Mach stems. By using this approach, the problem of 3D steady shock/shock interaction over 3D intersecting wedges was transformed into a 2D moving one on cross sections, which can be solved by shock-polar theory and shock dynamics theory. The properties of Mach interaction over 3D intersecting wedges can be analyzed with the new method,including pressure, temperature, density in the vicinity of triple points, location, and Mach number behind Mach stems.Theoretical results were compared with numerical results,and good agreement was obtained. Also, the influence of Mach number and wedge angle on the properties of a 3D Mach stem was studied.
文摘A new three-dimensional nickel(Ⅱ) hydrogen-bonded molecular self assembly containing [(Ni(nicotinamide)2(thiocyanate)2(H2O)2] complex has been synthesized and characterized by single-crystal X-ray diffraction,FTIR spectroscopy,thermal analysis and magnetic measurements.Structural analysis reveals that the complex crystallizes in triclinic space group P1(crystal data a = 7.5574,b = 8.2683,c = 9.0056 A,α = 73.010,β = 69.698,γ = 66.51) and exhibits a distorted octahedral coordination sphere.Most interesting point in its structure is the involvement of sulphur atom of thiocyanate moiety in the trifurcated hydrogen bonding to build up the hydrogen-bonded self assembly.The magnetic behavior as determined by squid magnetometer(2~300 K temp.range) reveals dominating antiferromagnetic interaction followed by spin canting behavior below 20 K.
文摘Six degrees of freedom(6DoF)input interfaces are essential formanipulating virtual objects through translation or rotation in three-dimensional(3D)space.A traditional outside-in tracking controller requires the installation of expensive hardware in advance.While inside-out tracking controllers have been proposed,they often suffer from limitations such as interaction limited to the tracking range of the sensor(e.g.,a sensor on the head-mounted display(HMD))or the need for pose value modification to function as an input interface(e.g.,a sensor on the controller).This study investigates 6DoF pose estimation methods without restricting the tracking range,using a smartphone as a controller in augmented reality(AR)environments.Our approach involves proposing methods for estimating the initial pose of the controller and correcting the pose using an inside-out tracking approach.In addition,seven pose estimation algorithms were presented as candidates depending on the tracking range of the device sensor,the tracking method(e.g.,marker recognition,visual-inertial odometry(VIO)),and whether modification of the initial pose is necessary.Through two experiments(discrete and continuous data),the performance of the algorithms was evaluated.The results demonstrate enhanced final pose accuracy achieved by correcting the initial pose.Furthermore,the importance of selecting the tracking algorithm based on the tracking range of the devices and the actual input value of the 3D interaction was emphasized.
基金supported by the National Basic Research Program of China(973 Program)(No.2013CB328806)the National High Technology Research and Development Program of China(863 Program)(No.2012AA011902)+1 种基金the National Natural Science Foundation of China(No.61177015)the Research Funds for the Central Universities of China(No.2012XZZX013)
文摘Based on light field reconstruction and motion recognition technique, a penetrable interactive floating 3D display system is proposed. The system consists of a high-frame-rate projector, a flat directional diffusing screen, a high-speed data transmission module, and a Kinect somatosensory device. The floating occlusioncorrect 3D image could rotate around some axis at different speeds according to user's hand motion. Eight motion directions and speed are detected accurately, and the prototype system operates efficiently with a recognition accuracy of 90% on average.
文摘Subject Code:H06 With the support by the National Natural Science Foundation of China,a study by the research group led by Prof.Zou Weiguo(邹卫国)from the Institute of Biochemistry and Cell Biology,Shanghai Institutes for Biological Sciences,CAS demonstrates that E3ligase SMURF2maintains bone
基金financially supported by the National Natural Science Foundation of China(No.51373003)Beijing Natural Science Foundation(No.2122059)
文摘In this paper,2D asynchronous spectra generated by using the DAOSD approach was utilized to probe interactions between Nd^3+ and pyridinium dissolved in aqueous solution.A series of cross peaks in the resultant 2D asynchronous spectrum confirms the occurrence of intermolecular interaction between Nd^3+and pyridinium.However,no coordination occurs between Nd^3+ and pyridinium.Interaction between πelectron from aromatic system and/electron from lanthanide ions account for the appearance of cross peaks in 2D asynchronous spectra.Because of the interaction,the emission spectrum of pyridinium exhibits a significant change when neodymium perchlorate was introduced into the system.