Interaction flow field of the sonic air jet through diamond shaped orifices at different incidence angles （10 degrees, 27.5 degrees, 45 degrees and 90 degrees） and total pressures （0.10 MPa and 0. 46 MPa） with a M...Interaction flow field of the sonic air jet through diamond shaped orifices at different incidence angles （10 degrees, 27.5 degrees, 45 degrees and 90 degrees） and total pressures （0.10 MPa and 0. 46 MPa） with a Mach 5.0 freestream was studied experimentally. A 90 degrees circular injector was examined for comparison. Crosssection Mach number contours were acquired by a Pitot-cone five-hole pressure probe. The results indicate that the low Mach semicircular region close to the wall is the wake region. The boundary layer thinning is in the areas adjacent to the wake. For the detached case, the interaction shock extends further into the freestream, and the shock shape has more curvature, also the low-Mach upwash region is larger. The vortices of the plume and the height of the jet interaction shock increase with increasing incidence angle and jet pressure. 90 degrees diamond and circular injector have stronger plume vorticity, and for the circular injector low-Mach region is smaller than that for the diamond injector. Tapered ramp increases the plume vorticity, and the double ramp reduces the level of vorticity. The three-dimensional interaction shock shape was modeled from the surface shock shape, the center plane shock shape, and crosssectional shock shape. The shock total pressure was estimated with the normal component of the Mach number using normal shock theory. The shock induced total pressure losses decrease with decreasing jet incidence angle and injection pressure, where the largest losses are incurred by the 90 degrees, circular injector.展开更多
A novel method is proposed to measure the interaction cross sections of short-lived hypernuclei with the WASA-FRS experimental setup at GSI and FAIR.The interaction cross sections of hypernuclei,produced in projectile...A novel method is proposed to measure the interaction cross sections of short-lived hypernuclei with the WASA-FRS experimental setup at GSI and FAIR.The interaction cross sections of hypernuclei,produced in projectile fragmentation reactions at relativistic energies,can be determined from their production point distribution within a target.The feasibility of such a measurement is evaluated through detailed Monte Carlo simulations.The results indicate that an aimed uncertainty on the order of 10%can be achieved for the case of a hypertriton,demonstrating the potential of this method for studying matter radii and the possible hyperon halo structure of hypernuclei.展开更多
The rapid growth of structured data has presented new technological challenges in the research fields of big data and relational database. In this paper, we present an efficient system for managing and analyzing PB le...The rapid growth of structured data has presented new technological challenges in the research fields of big data and relational database. In this paper, we present an efficient system for managing and analyzing PB level structured data called Banian. Banian overcomes the storage structure limitation of relational database and effectively integrates interactive query with large-scale storage management. It provides a uniform query interface for cross-platform datasets and thus shows favorable compatibility and scalability. Banian＇s system architecture mainly includes three layers：（1） a storage layer using HDFS for the distributed storage of massive data;（2） a scheduling and execution layer employing the splitting and scheduling technology of parallel database; and（3）an application layer providing a cross-platform query interface and supporting standard SQL. We evaluate Banian using PB level Internet data and the TPC-H benchmark. The results show that when compared with Hive, Banian improves the query performance to a maximum of 30 times and achieves better scalability and concurrency.展开更多
Predicting the physical and mechanical properties of organic materials from purely chemical understandings remains a significant challenge due to the limitations of conventional force fields in molecular dynamics(MD)....Predicting the physical and mechanical properties of organic materials from purely chemical understandings remains a significant challenge due to the limitations of conventional force fields in molecular dynamics(MD).In this work,we present a novel reformulation of Class II force fields that integrates Morse bond potentials with newly derived cross-term interactions,explicitly capturing complete bond dissociation while maintaining computational efficiency.This reformulated functional form combines the stability of fixed-bond models with the reactive capabilities of bond-breaking force fields,achieving accurate and robust MD predictions across crystalline,semi-crystalline,and amorphous organic systems.Extensive benchmarking confirms its predictive accuracy and speed,enabling high-throughput structure–property mapping for integrated computational materials engineering.Reparameterization methods have been implemented in the LUNAR software,which provides a user-friendly interface for rapid MD model development and accelerates materials discovery for composite applications.展开更多
文摘Interaction flow field of the sonic air jet through diamond shaped orifices at different incidence angles （10 degrees, 27.5 degrees, 45 degrees and 90 degrees） and total pressures （0.10 MPa and 0. 46 MPa） with a Mach 5.0 freestream was studied experimentally. A 90 degrees circular injector was examined for comparison. Crosssection Mach number contours were acquired by a Pitot-cone five-hole pressure probe. The results indicate that the low Mach semicircular region close to the wall is the wake region. The boundary layer thinning is in the areas adjacent to the wake. For the detached case, the interaction shock extends further into the freestream, and the shock shape has more curvature, also the low-Mach upwash region is larger. The vortices of the plume and the height of the jet interaction shock increase with increasing incidence angle and jet pressure. 90 degrees diamond and circular injector have stronger plume vorticity, and for the circular injector low-Mach region is smaller than that for the diamond injector. Tapered ramp increases the plume vorticity, and the double ramp reduces the level of vorticity. The three-dimensional interaction shock shape was modeled from the surface shock shape, the center plane shock shape, and crosssectional shock shape. The shock total pressure was estimated with the normal component of the Mach number using normal shock theory. The shock induced total pressure losses decrease with decreasing jet incidence angle and injection pressure, where the largest losses are incurred by the 90 degrees, circular injector.
文摘A novel method is proposed to measure the interaction cross sections of short-lived hypernuclei with the WASA-FRS experimental setup at GSI and FAIR.The interaction cross sections of hypernuclei,produced in projectile fragmentation reactions at relativistic energies,can be determined from their production point distribution within a target.The feasibility of such a measurement is evaluated through detailed Monte Carlo simulations.The results indicate that an aimed uncertainty on the order of 10%can be achieved for the case of a hypertriton,demonstrating the potential of this method for studying matter radii and the possible hyperon halo structure of hypernuclei.
基金supported by the National High-Tech Research and Development (863) Program of China (No. 2012AA012609)
文摘The rapid growth of structured data has presented new technological challenges in the research fields of big data and relational database. In this paper, we present an efficient system for managing and analyzing PB level structured data called Banian. Banian overcomes the storage structure limitation of relational database and effectively integrates interactive query with large-scale storage management. It provides a uniform query interface for cross-platform datasets and thus shows favorable compatibility and scalability. Banian＇s system architecture mainly includes three layers：（1） a storage layer using HDFS for the distributed storage of massive data;（2） a scheduling and execution layer employing the splitting and scheduling technology of parallel database; and（3）an application layer providing a cross-platform query interface and supporting standard SQL. We evaluate Banian using PB level Internet data and the TPC-H benchmark. The results show that when compared with Hive, Banian improves the query performance to a maximum of 30 times and achieves better scalability and concurrency.
基金supported by the NASA Space Technology Research Institute(STRI)for Ultra-Strong Composites by Computational Designs(US-COMP),grant NNX17AJ32GAir Force Research Laboratory(grant FA239424CB014)the Cohodas Graduate Fellowship.SUPERIOR,a high-performance computing cluster at Michigan Technological University,was used in obtaining the MD simulation results presented in this publication.The authors would like to thank the Computational Mechanics&Materials Research(CMMR)Lab members at Michigan Technological University for their valuable discussion and insights.
文摘Predicting the physical and mechanical properties of organic materials from purely chemical understandings remains a significant challenge due to the limitations of conventional force fields in molecular dynamics(MD).In this work,we present a novel reformulation of Class II force fields that integrates Morse bond potentials with newly derived cross-term interactions,explicitly capturing complete bond dissociation while maintaining computational efficiency.This reformulated functional form combines the stability of fixed-bond models with the reactive capabilities of bond-breaking force fields,achieving accurate and robust MD predictions across crystalline,semi-crystalline,and amorphous organic systems.Extensive benchmarking confirms its predictive accuracy and speed,enabling high-throughput structure–property mapping for integrated computational materials engineering.Reparameterization methods have been implemented in the LUNAR software,which provides a user-friendly interface for rapid MD model development and accelerates materials discovery for composite applications.
