Climatological patterns in wind fluctuations on time scales of 1–10 h are analyzed at a meteorological mast at the Yangmeishan wind farm, Yunnan Province,China, using a 2-yr time series of 10-min wind speed observati...Climatological patterns in wind fluctuations on time scales of 1–10 h are analyzed at a meteorological mast at the Yangmeishan wind farm, Yunnan Province,China, using a 2-yr time series of 10-min wind speed observations. For analyzing the spectral properties of nonstationary wind fluctuations in mountain terrain, the Hilbert-Huang transform(HHT) is applied to investigate climatological patterns between wind variability and several variables including time of year, time of day, wind direction, and pressure tendency. Compared with that for offshore sites, the wind variability at Yangmeishan wind farm has a more distinct diurnal cycle, but the seasonal discrepancies and the differences according to directions are not distinct, and the synoptic influences on wind variability are weaker. There is enhanced variability in spring and winter compared with summer and autumn. For flow from the main direction sector, the maximum wind variability is observed in spring. And the severe wind fluctuations are more common when the pressure tendency is rising.展开更多
We examine the time development of a wavepacket in a Non-Hermitian PT symmetric tight-bindingchain based on the Bethe ansatz solutions.The complete orthogonal sets in both unbroken and broken PT symmetryregions are es...We examine the time development of a wavepacket in a Non-Hermitian PT symmetric tight-bindingchain based on the Bethe ansatz solutions.The complete orthogonal sets in both unbroken and broken PT symmetryregions are established with respect to an inner product in terms of CPT conjugation.The dynamical development ofa stationary wavepacket is exhibited,showing the impacts from additional imaginary potentials within unbroken andbroken symmetric regimes.Our result indicates that there are distinct dynamic characteristics for both two regions.Theunbroken symmetric imaginary end potentials can be regarded as a special kind of boundary condition in the sense ofHermitian quantum mechanics.展开更多
Based on the Weierstrass elliptic function equation, a new Weierstrass semi-rational expansion method and its algorithm are presented. The main idea of the method changes the problem solving soliton equations into ano...Based on the Weierstrass elliptic function equation, a new Weierstrass semi-rational expansion method and its algorithm are presented. The main idea of the method changes the problem solving soliton equations into another one solving the corresponding set of nonlinear algebraic equations. With the aid of Maple, we choose the modified KdV equation, (2+ 1)-dimensional KP equation, and (3+1)-dimensional Jimbo-Miwa equation to illustrate our algorithm. As a consequence, many types of new doubly periodic solutions are obtained in terms of the Weierstrass elliptic function.Moreover the corresponding new Jacobi elliptic function solutions and solitary wave solutions are also presented as simple limits of doubly periodic solutions.展开更多
This paper proposes and examines four basic organizational modes of production fragmentation＇in manufacturing industries based on three case studies. Our study shows that manufacturing enterprises weigh technology an...This paper proposes and examines four basic organizational modes of production fragmentation＇in manufacturing industries based on three case studies. Our study shows that manufacturing enterprises weigh technology and cost against the intensity of market competition in their choice of mode and the corresponding extent of production fragmentation, in industries where competition is less intense, enterprises prioritize technology concern and are inclined to choose an internally integrated organizational mode, characterized by independent investment in building their own manufacturing plants. In industries where competition is more intense, enterprises prioritize cost concern and are inclined to adopt an outsourcing-based organizational mode, characterized by maximizing the usage of third-party facilities. In sum, more intense competition prompts enterprises to seek efficiency by relying on a broader range of manufacturing locations, suppliers, and partners and, thus, to adopt more open organizational modes. We argue that a deeper understanding of how enterprises select organizational modes, combined with strategic policy aimed at promoting openness in manufacturing industries, will enhance the role of China＇s industries in the global production chain.展开更多
In this paper,we introduce the most key points during the implementation of Bunch-by-Bunch transverse feedback system of HLS(Hefei Light Soure),such as the vector computation,the notch filter development,the data proc...In this paper,we introduce the most key points during the implementation of Bunch-by-Bunch transverse feedback system of HLS(Hefei Light Soure),such as the vector computation,the notch filter development,the data processing,the phase space reconstruction method based on Hilbert transform,the mode analysis,and the development of feedback kicker cavity.展开更多
Following recent rapid developments in tunnel engineering in China,the heavy structural maintenance work of the future is likely to pose a great challenge.Newly developed vibration-based health assessment and monitori...Following recent rapid developments in tunnel engineering in China,the heavy structural maintenance work of the future is likely to pose a great challenge.Newly developed vibration-based health assessment and monitoring methods offer good prospects for large-scale structural monitoring,hidden surface detection and disease pre-judgment.However,because the dynamic properties of tunnels are sensitive to the coupling and damping effects of the surrounding soil,there is little relevant research on tunnel structures.Using the PiP(pipe in pipe)model,the intrinsic tunnel modes and their response characteristics are investigated in this paper,and the degree to which the identification of these characteristics is influenced by mode superposition and the soil coupling effect are also considered.The response features of these flexible wave modes are found to be barely recognizable in a tunnel-soil coupled system,while the phase velocity of the torsional wave can be determined by combining phase spectrum analysis and the HHT(Hilbert-Huang transformation)method.A new structural health assessment method based on the torsional wave speed is therefore proposed.In this method,the torsional wave speed is used to determine the tunnel structure’s global stiffness based on a newly developed dispersion algorithm.The calculated stiffness is then used to evaluate the tunnel’s structural service status.A field test was also carried out at a newly built tunnel to validate the proposed method;the tunnel structure’s Young’s modulus was obtained and was very close to the designed value.This indicates that this method is an effective way to assess tunnel service conditions,and also provides a theoretical basis for future applications to health assessment of shield tunnels.展开更多
Microwave radiometers have many applications because of their penetration ability. However, two major problems remain that obstruct the development of microwave research. One factor that limits their commercial applic...Microwave radiometers have many applications because of their penetration ability. However, two major problems remain that obstruct the development of microwave research. One factor that limits their commercial application is the relatively low resolution of microwave radiometers. The other is the non-uniform spatial resolution for each frequency of the radiometer. The resolution mismatch becomes a critical consideration when observations at two or more frequencies must be combined. In this paper, we have used the Backus-Gilbert method to solve these two problems, while AMSR-E is chosen as the research object. First, we derived the Backus-Gilbert method in detail. The simulated data were then used to decide the optimum parameters in the Backus-Gilbert method. To enhance the resolution, the Backus-Gilbert method has been applied to the AMSR-E data, which covered the Mexico Gulf and the Amazon River. After resolution was enhanced, detailed information was obtained and compared with visible high resolution data. To match the resolution, the AMSR-E data from the Oklahoma Little Washed were used to compute the Microwave Vegetation Index (MVI), which was developed by J. C. Shi. Compared to the original MVIs, the information contained in the MVIs that were processed by the Backus-Gilbert method is more reliable.展开更多
By virtue of the two-layer picture of Pfatfian pair Hall state, a qubit representation of topological degeneracy for quasiholes excitation is displayed. The non-Abelian feature of states can be manifested readily by t...By virtue of the two-layer picture of Pfatfian pair Hall state, a qubit representation of topological degeneracy for quasiholes excitation is displayed. The non-Abelian feature of states can be manifested readily by the new wave functions. The virtue of this approach is that one does not need to find the equalities of Pfalfians, which is a so tedious task as exemplified for the case of six quasiholes. Then the braiding matrices are also constructed readily by just permutating single-qubit states, which are unitary and hermite.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 91215302 and 41101045)the "One-Three-Five" Strategic Planning of the Institute of Atmospheric Physics, Chinese Academy of Sciences (Grant No. Y267014601)
文摘Climatological patterns in wind fluctuations on time scales of 1–10 h are analyzed at a meteorological mast at the Yangmeishan wind farm, Yunnan Province,China, using a 2-yr time series of 10-min wind speed observations. For analyzing the spectral properties of nonstationary wind fluctuations in mountain terrain, the Hilbert-Huang transform(HHT) is applied to investigate climatological patterns between wind variability and several variables including time of year, time of day, wind direction, and pressure tendency. Compared with that for offshore sites, the wind variability at Yangmeishan wind farm has a more distinct diurnal cycle, but the seasonal discrepancies and the differences according to directions are not distinct, and the synoptic influences on wind variability are weaker. There is enhanced variability in spring and winter compared with summer and autumn. For flow from the main direction sector, the maximum wind variability is observed in spring. And the severe wind fluctuations are more common when the pressure tendency is rising.
基金Support by the CNSF Grants Nos.10874091 and 2006CB921205
文摘We examine the time development of a wavepacket in a Non-Hermitian PT symmetric tight-bindingchain based on the Bethe ansatz solutions.The complete orthogonal sets in both unbroken and broken PT symmetryregions are established with respect to an inner product in terms of CPT conjugation.The dynamical development ofa stationary wavepacket is exhibited,showing the impacts from additional imaginary potentials within unbroken andbroken symmetric regimes.Our result indicates that there are distinct dynamic characteristics for both two regions.Theunbroken symmetric imaginary end potentials can be regarded as a special kind of boundary condition in the sense ofHermitian quantum mechanics.
基金National Key Basic Research Project of China under，国家自然科学基金，教育部留学回国人员科研启动基金
文摘Based on the Weierstrass elliptic function equation, a new Weierstrass semi-rational expansion method and its algorithm are presented. The main idea of the method changes the problem solving soliton equations into another one solving the corresponding set of nonlinear algebraic equations. With the aid of Maple, we choose the modified KdV equation, (2+ 1)-dimensional KP equation, and (3+1)-dimensional Jimbo-Miwa equation to illustrate our algorithm. As a consequence, many types of new doubly periodic solutions are obtained in terms of the Weierstrass elliptic function.Moreover the corresponding new Jacobi elliptic function solutions and solitary wave solutions are also presented as simple limits of doubly periodic solutions.
文摘This paper proposes and examines four basic organizational modes of production fragmentation＇in manufacturing industries based on three case studies. Our study shows that manufacturing enterprises weigh technology and cost against the intensity of market competition in their choice of mode and the corresponding extent of production fragmentation, in industries where competition is less intense, enterprises prioritize technology concern and are inclined to choose an internally integrated organizational mode, characterized by independent investment in building their own manufacturing plants. In industries where competition is more intense, enterprises prioritize cost concern and are inclined to adopt an outsourcing-based organizational mode, characterized by maximizing the usage of third-party facilities. In sum, more intense competition prompts enterprises to seek efficiency by relying on a broader range of manufacturing locations, suppliers, and partners and, thus, to adopt more open organizational modes. We argue that a deeper understanding of how enterprises select organizational modes, combined with strategic policy aimed at promoting openness in manufacturing industries, will enhance the role of China＇s industries in the global production chain.
文摘In this paper,we introduce the most key points during the implementation of Bunch-by-Bunch transverse feedback system of HLS(Hefei Light Soure),such as the vector computation,the notch filter development,the data processing,the phase space reconstruction method based on Hilbert transform,the mode analysis,and the development of feedback kicker cavity.
基金supported by the National Basic Research Program of China("973"Project)(Grant No.2011CB013803)the National Natural Science Foundation of China(Grant No.41372273)the Shanghai Science and Technology Development Funds(Grant Nos.12231200900,13231200102)
文摘Following recent rapid developments in tunnel engineering in China,the heavy structural maintenance work of the future is likely to pose a great challenge.Newly developed vibration-based health assessment and monitoring methods offer good prospects for large-scale structural monitoring,hidden surface detection and disease pre-judgment.However,because the dynamic properties of tunnels are sensitive to the coupling and damping effects of the surrounding soil,there is little relevant research on tunnel structures.Using the PiP(pipe in pipe)model,the intrinsic tunnel modes and their response characteristics are investigated in this paper,and the degree to which the identification of these characteristics is influenced by mode superposition and the soil coupling effect are also considered.The response features of these flexible wave modes are found to be barely recognizable in a tunnel-soil coupled system,while the phase velocity of the torsional wave can be determined by combining phase spectrum analysis and the HHT(Hilbert-Huang transformation)method.A new structural health assessment method based on the torsional wave speed is therefore proposed.In this method,the torsional wave speed is used to determine the tunnel structure’s global stiffness based on a newly developed dispersion algorithm.The calculated stiffness is then used to evaluate the tunnel’s structural service status.A field test was also carried out at a newly built tunnel to validate the proposed method;the tunnel structure’s Young’s modulus was obtained and was very close to the designed value.This indicates that this method is an effective way to assess tunnel service conditions,and also provides a theoretical basis for future applications to health assessment of shield tunnels.
基金supported by Chinese Special Funds for National Basic Research Project of China (Grant No. 2007CB714403)National High Technology Research and Development Program of China (Grant Nos. 2007AA12Z135, 2008AA12Z110)Chinese Academy of Sciences (Grant No. KZCX2-YW-Q10-2)
文摘Microwave radiometers have many applications because of their penetration ability. However, two major problems remain that obstruct the development of microwave research. One factor that limits their commercial application is the relatively low resolution of microwave radiometers. The other is the non-uniform spatial resolution for each frequency of the radiometer. The resolution mismatch becomes a critical consideration when observations at two or more frequencies must be combined. In this paper, we have used the Backus-Gilbert method to solve these two problems, while AMSR-E is chosen as the research object. First, we derived the Backus-Gilbert method in detail. The simulated data were then used to decide the optimum parameters in the Backus-Gilbert method. To enhance the resolution, the Backus-Gilbert method has been applied to the AMSR-E data, which covered the Mexico Gulf and the Amazon River. After resolution was enhanced, detailed information was obtained and compared with visible high resolution data. To match the resolution, the AMSR-E data from the Oklahoma Little Washed were used to compute the Microwave Vegetation Index (MVI), which was developed by J. C. Shi. Compared to the original MVIs, the information contained in the MVIs that were processed by the Backus-Gilbert method is more reliable.
基金Supported by National Natural Science Foundation of China under Grant Nos.11005002 and 11005003New Century Excellent Talent of M.O.E(NCET-11-0937)Sponsoring Program of Excellent Younger Teachers in universities in Henan Province of China under Grant No.2010GGJS-181
文摘By virtue of the two-layer picture of Pfatfian pair Hall state, a qubit representation of topological degeneracy for quasiholes excitation is displayed. The non-Abelian feature of states can be manifested readily by the new wave functions. The virtue of this approach is that one does not need to find the equalities of Pfalfians, which is a so tedious task as exemplified for the case of six quasiholes. Then the braiding matrices are also constructed readily by just permutating single-qubit states, which are unitary and hermite.
