The QUAD(Quasi-Accurate Detection of gross errors) method which is originally developed to detect gross errors in the geodetic data is extended and used to select and identify relatively stable stations. The formulas ...The QUAD(Quasi-Accurate Detection of gross errors) method which is originally developed to detect gross errors in the geodetic data is extended and used to select and identify relatively stable stations. The formulas and algorithm are described in detail. Some problems that should be noticed in the use of this method are discussed. Finally, this method is applied to some data observed in North China as an example.展开更多
For the quad tilt rotor aircraft, a computational fluid dynamics method based on multiple reference frames (MRF) was used to analyze the influence of aerodynamic layout parameters on the aerodynamic characteristics of...For the quad tilt rotor aircraft, a computational fluid dynamics method based on multiple reference frames (MRF) was used to analyze the influence of aerodynamic layout parameters on the aerodynamic characteristics of the quad tilt rotor aircraft. Firstly, a numerical simulation method for the interference flow field of the quad tilt rotor aircraft is established. Based on this method, the aerodynamic characteristics of isolated rotors, rotor combinations at different lateral positions on the wing, and rotor rotation directions under different inflow velocities were calculated and analyzed, in order to grasp their aerodynamic interference laws and provide reference for the design and control theory research of such aircraft.展开更多
In this paper, a new idea that combines Quasi-Accurate Detection of gross errors (QUAD) with discontinuous deformation positive analysis, is brought forward to divide the regional active blocks. The method can improve...In this paper, a new idea that combines Quasi-Accurate Detection of gross errors (QUAD) with discontinuous deformation positive analysis, is brought forward to divide the regional active blocks. The method can improve the demarcation of active blocks for areas lacking with observation data and offer a new train of through for the complete study of the regional deformation of active blocks. In addition, using the Sichuan-Yunnan area as example, the practice process of the method is introduced briefly.展开更多
Based on the horizontal movement velocities and their error estimations of 144 GPS stations in North China de-duced from the results obtained from multiple GPS measurements carried out in the period of 1992~2001, the ...Based on the horizontal movement velocities and their error estimations of 144 GPS stations in North China de-duced from the results obtained from multiple GPS measurements carried out in the period of 1992~2001, the horizontal deformation in the area is studied. The movements, entire deformations, local deformations, activity patterns and intensities along the boundary zones are derived. And then the risk of strong earthquake in the area is estimated. In the research, the horizontal displacement observations can be considered as the sum of three parts. The first part is the entire motion following Eurasian plate, which can be derived from NUVAL-IA model; the second part is the relative motions and deformations between the sub-tectonic blocks in the studied area, which can be derived from a set of displacement observations determined by the expanded QUAD method in the paper; the third part is the local deformations and errors in the sub-tectonic blocks, which can be described as the inhomoge-neous strains of the block. The method and results are introduced in detail in the paper.展开更多
文摘The QUAD(Quasi-Accurate Detection of gross errors) method which is originally developed to detect gross errors in the geodetic data is extended and used to select and identify relatively stable stations. The formulas and algorithm are described in detail. Some problems that should be noticed in the use of this method are discussed. Finally, this method is applied to some data observed in North China as an example.
文摘For the quad tilt rotor aircraft, a computational fluid dynamics method based on multiple reference frames (MRF) was used to analyze the influence of aerodynamic layout parameters on the aerodynamic characteristics of the quad tilt rotor aircraft. Firstly, a numerical simulation method for the interference flow field of the quad tilt rotor aircraft is established. Based on this method, the aerodynamic characteristics of isolated rotors, rotor combinations at different lateral positions on the wing, and rotor rotation directions under different inflow velocities were calculated and analyzed, in order to grasp their aerodynamic interference laws and provide reference for the design and control theory research of such aircraft.
基金This research was sponsored by the Joint EarthquakeScience Foundation (603002) and 104011)the sub-project of the 10th"Five-Year"Key Research Program ofCEA,entitled"Variation patterns of tectonic deformation and strain accumulation state in the key areas on the Chinesecontinent".
文摘In this paper, a new idea that combines Quasi-Accurate Detection of gross errors (QUAD) with discontinuous deformation positive analysis, is brought forward to divide the regional active blocks. The method can improve the demarcation of active blocks for areas lacking with observation data and offer a new train of through for the complete study of the regional deformation of active blocks. In addition, using the Sichuan-Yunnan area as example, the practice process of the method is introduced briefly.
基金State Key Basic Research Development and Programming Project Mechanism and Prediction of Strong Continental Earthquakes (G1998040703).
文摘Based on the horizontal movement velocities and their error estimations of 144 GPS stations in North China de-duced from the results obtained from multiple GPS measurements carried out in the period of 1992~2001, the horizontal deformation in the area is studied. The movements, entire deformations, local deformations, activity patterns and intensities along the boundary zones are derived. And then the risk of strong earthquake in the area is estimated. In the research, the horizontal displacement observations can be considered as the sum of three parts. The first part is the entire motion following Eurasian plate, which can be derived from NUVAL-IA model; the second part is the relative motions and deformations between the sub-tectonic blocks in the studied area, which can be derived from a set of displacement observations determined by the expanded QUAD method in the paper; the third part is the local deformations and errors in the sub-tectonic blocks, which can be described as the inhomoge-neous strains of the block. The method and results are introduced in detail in the paper.
