The performance of slowed-rotor compound aircraft,particularly at high-speed flight condition,is examined.The forward flight performance calculation model of the composite helicopter is established,and the appropriate...The performance of slowed-rotor compound aircraft,particularly at high-speed flight condition,is examined.The forward flight performance calculation model of the composite helicopter is established,and the appropriate wing and propeller parameters are determined.The predicted performance of isolated propeller,wing and rotor combination is examined.Three kinds of tip speed and a range of load share setting are investigated.Propeller bearing 80%of the thrust with wing sharing lift is found to be the best condition to have better performance and the maximum L/D for maximum forward speed.Detailed rotor,propeller,and wing performance are examined for sea level,1000 m,and 2000 m cruise altitude.Rotor,propeller,and wing power are found to be largely from profile drag,except at low speed where the wing is near stall.Increased elevation offloads lift from the rotor to the wing,dropping the total power required and increasing the maximum speed limit over 400 km/h.展开更多
Within the framework of an effective field approximation, the effects of single-ion anisotropy and different trimodal transverse fields of two sublattices on the critical properties of the mixed spin-1/2 and spin-1 Is...Within the framework of an effective field approximation, the effects of single-ion anisotropy and different trimodal transverse fields of two sublattices on the critical properties of the mixed spin-1/2 and spin-1 Ising system are investigated on the simple cubic lattice. A smaller single-lon anisotropy can magnify magnetic ordering phases and a larger one can depress magnetic ordering phase for T-Ω1/2 space at low temperatures, while a smaller single-ion anisotropy can hardly change the value of critical transverse field for T-Ω1 space. On the other hand, influences of two different trimodal transverse fields concentrations on tricritical points and magnetic ordering phases take on some interesting results in T-D space. The main reason comes from the common action of single-ion anisotropy, different transverse fields and two trimodal distributions.展开更多
Based on the Kubo formalism, the anomalous Hall effect in a magnetic two-dimensional hole gas with cubic-Rashba spin-orbit coupling is studied in the presence of δ-function scattering potential. When the weak, shortr...Based on the Kubo formalism, the anomalous Hall effect in a magnetic two-dimensional hole gas with cubic-Rashba spin-orbit coupling is studied in the presence of δ-function scattering potential. When the weak, shortranged disorder scattering is considered in the Born approximation, we find that the self-energy becomes diagonal in the helicity basis and its value is independent of the wave number, and the vertex correction to the anomalous Hall conductivity due to impurity scattering vanishes when both subbands are occupied. That is to say, the anomalous Hall effect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system, which is in sharp contrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering is considered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.展开更多
A new automatic rotary compactor and its abilities in compacting stone mastic asphalt (SMA) are presented. Following an overview of the rotary compactor and the compaction procedure, it is demonstrated that the rota...A new automatic rotary compactor and its abilities in compacting stone mastic asphalt (SMA) are presented. Following an overview of the rotary compactor and the compaction procedure, it is demonstrated that the rotary compactor is able to produce uniform slabs with the desired thickness of 65 mm all over around. Furthermore, 132 cored samples from the rotary compactor had been compacted uniformly with approximately 4% optimum air void content. In addition, performance tests results indicate that the rotary compactor produces asphalt mixturures with the requirements of resilient modulus, Marshall stability and flow. A weight factor was introduced for each fraction of aggregates in the degradation analysis to compensate the crushing effect of aggregates during mixing and compacting.展开更多
Multi-mode spiral wave and its breakup in 1-d and 2-d coupled oscillatory media is studied here by theoretic analysis and numerical simulations. The analysis in 1-d system shows that the dispersion relation curve coul...Multi-mode spiral wave and its breakup in 1-d and 2-d coupled oscillatory media is studied here by theoretic analysis and numerical simulations. The analysis in 1-d system shows that the dispersion relation curve could be nonmonotonic depending on the coupling strength. It may also lead to the coexistence of different wave numbers within one system. Direct numerical observations in 1-d and 2-d systems conform to the prediction of dispersion relation analysis. Our findings indicate that the wave grouping can also be observed in oscillatory media without tip meandering and waves with negative group velocity can occur without inhomogeneity.展开更多
The mixed spin P-fields (MSP for short) theory sets up a geometric platform to relate Gromov-Witten invariants of the quintic three-fold and Fan-Jarvis-Ruan-Witten invariants of the quintic polynomial in five variab...The mixed spin P-fields (MSP for short) theory sets up a geometric platform to relate Gromov-Witten invariants of the quintic three-fold and Fan-Jarvis-Ruan-Witten invariants of the quintic polynomial in five variables. It starts with Wittens vision and the P-fields treatment of GW invariants and FJRW invaxiants. Then it briefly discusses the master space technique and its application to the set-up of the MSP moduli. Some key results in MSP theory are explained and some examples are provided.展开更多
文摘The performance of slowed-rotor compound aircraft,particularly at high-speed flight condition,is examined.The forward flight performance calculation model of the composite helicopter is established,and the appropriate wing and propeller parameters are determined.The predicted performance of isolated propeller,wing and rotor combination is examined.Three kinds of tip speed and a range of load share setting are investigated.Propeller bearing 80%of the thrust with wing sharing lift is found to be the best condition to have better performance and the maximum L/D for maximum forward speed.Detailed rotor,propeller,and wing performance are examined for sea level,1000 m,and 2000 m cruise altitude.Rotor,propeller,and wing power are found to be largely from profile drag,except at low speed where the wing is near stall.Increased elevation offloads lift from the rotor to the wing,dropping the total power required and increasing the maximum speed limit over 400 km/h.
基金The project supported partly by the Key Projects of Natural Science Foundation of Jiangsu Province of China under Grant No. 03KJA140117 and the 0pen Foundation of Jiangsu Key Laboratory of Thin Films under Grant No. K2022
文摘Within the framework of an effective field approximation, the effects of single-ion anisotropy and different trimodal transverse fields of two sublattices on the critical properties of the mixed spin-1/2 and spin-1 Ising system are investigated on the simple cubic lattice. A smaller single-lon anisotropy can magnify magnetic ordering phases and a larger one can depress magnetic ordering phase for T-Ω1/2 space at low temperatures, while a smaller single-ion anisotropy can hardly change the value of critical transverse field for T-Ω1 space. On the other hand, influences of two different trimodal transverse fields concentrations on tricritical points and magnetic ordering phases take on some interesting results in T-D space. The main reason comes from the common action of single-ion anisotropy, different transverse fields and two trimodal distributions.
基金Supported by the Research Fund for Outstanding Young Teachers in Higher Education Institutions of Shanghai under Grant No.gjd08040the Scientific Research Startup Funds of SUESthe National Natural Science Foundation of China under Grant No.C-6201-10-001
文摘Based on the Kubo formalism, the anomalous Hall effect in a magnetic two-dimensional hole gas with cubic-Rashba spin-orbit coupling is studied in the presence of δ-function scattering potential. When the weak, shortranged disorder scattering is considered in the Born approximation, we find that the self-energy becomes diagonal in the helicity basis and its value is independent of the wave number, and the vertex correction to the anomalous Hall conductivity due to impurity scattering vanishes when both subbands are occupied. That is to say, the anomalous Hall effect is not vanishing or influenced by the vertex correction for two-dimensional heavy-hole system, which is in sharp contrast to the case of linear-Rashba spin-orbit coupling in the electron band when the short-range disorder scattering is considered and the extrinsic mechanism as well as the effect of external electric field on the SO interaction are ignored.
基金the Ministry of Higher Education for funding this research
文摘A new automatic rotary compactor and its abilities in compacting stone mastic asphalt (SMA) are presented. Following an overview of the rotary compactor and the compaction procedure, it is demonstrated that the rotary compactor is able to produce uniform slabs with the desired thickness of 65 mm all over around. Furthermore, 132 cored samples from the rotary compactor had been compacted uniformly with approximately 4% optimum air void content. In addition, performance tests results indicate that the rotary compactor produces asphalt mixturures with the requirements of resilient modulus, Marshall stability and flow. A weight factor was introduced for each fraction of aggregates in the degradation analysis to compensate the crushing effect of aggregates during mixing and compacting.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 20573134, 10875011the Natural Science Foundation of Xuzhou Normal University under Grant No. 07PYL02
文摘Multi-mode spiral wave and its breakup in 1-d and 2-d coupled oscillatory media is studied here by theoretic analysis and numerical simulations. The analysis in 1-d system shows that the dispersion relation curve could be nonmonotonic depending on the coupling strength. It may also lead to the coexistence of different wave numbers within one system. Direct numerical observations in 1-d and 2-d systems conform to the prediction of dispersion relation analysis. Our findings indicate that the wave grouping can also be observed in oscillatory media without tip meandering and waves with negative group velocity can occur without inhomogeneity.
基金supported by Hong Kong General Research Fund(Nos.600711,6301515,602512)the National Science Foundation(Nos.NSF-1104553,DMS-1159156,DMS-1206667,DMS-1159416)
文摘The mixed spin P-fields (MSP for short) theory sets up a geometric platform to relate Gromov-Witten invariants of the quintic three-fold and Fan-Jarvis-Ruan-Witten invariants of the quintic polynomial in five variables. It starts with Wittens vision and the P-fields treatment of GW invariants and FJRW invaxiants. Then it briefly discusses the master space technique and its application to the set-up of the MSP moduli. Some key results in MSP theory are explained and some examples are provided.