We recommend a new convenient method for disentangling some exponential operators and derive a set of new operator identities. Especially, we derive the normal odering form of exp [fa^＋a ＋ ga^2＋ ＋ ka^2] without ap...We recommend a new convenient method for disentangling some exponential operators and derive a set of new operator identities. Especially, we derive the normal odering form of exp [fa^＋a ＋ ga^2＋ ＋ ka^2] without appealing to Lie algebra method. Application of these formulas in solving some dynamic Hamiltonian is presented.展开更多
In the preceding paper [Commun. Theor. Phys. 51 （2009） 321] we have recommended a convenient method for disentangling exponential operators in the form of exp{B ＋ C}, trying to find an operator A that satisfies [A,...In the preceding paper [Commun. Theor. Phys. 51 （2009） 321] we have recommended a convenient method for disentangling exponential operators in the form of exp{B ＋ C}, trying to find an operator A that satisfies [A, B] = C, and [A, [A, B]] = 0, then from the Baker-Hausdorff formula we have exp{B ＋C} ： exp（B ＋ [A, B]} = e^A e^B e^-A. After arranging e^Ae^B = e^B e^A e^W, the disentangling exp{B ＋ C} = e^B e^W is obtained. In this work we use this method to two-mode case, especially, derive the normal ordering form of exp[h（a^＋a ＋ b^＋b） ＋ ga^＋b^＋ ＋ kab] without appealing to Lie algebra method.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
Centrifugal pumps are being widely used in many industrial and commercial applications.Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations.The ...Centrifugal pumps are being widely used in many industrial and commercial applications.Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations.The purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed conditions.For this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump performance.The energy saving and therefore the cost saving depends on the specific duty cycle of which the machine operates.Duty cycle is the proportion of time during which a component,device and system is operated.The duty cycle segmented into different flow rates and weighting the average value for each segment by the interval time.The system was operated at 50%or less of the pump capacity.The input power of the system was carried out by pump characteristics curve of each operating point.The energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive operation.The total energy consumed for constant speed drive pump was 75,770 k W.hr and for variable speed drive pump was 31,700 k W.hr.The total energy saving of the system was 44,070 k W.hr or 58.16%annually.So,this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.展开更多
基金supported by the National Natural Science Foundation of China under Grant Nos.10475056 and 10775097
文摘We recommend a new convenient method for disentangling some exponential operators and derive a set of new operator identities. Especially, we derive the normal odering form of exp [fa^＋a ＋ ga^2＋ ＋ ka^2] without appealing to Lie algebra method. Application of these formulas in solving some dynamic Hamiltonian is presented.
基金supported by the National Natural Science Foundation of China under Grant Nos.10775097 and 10874174
文摘In the preceding paper [Commun. Theor. Phys. 51 （2009） 321] we have recommended a convenient method for disentangling exponential operators in the form of exp{B ＋ C}, trying to find an operator A that satisfies [A, B] = C, and [A, [A, B]] = 0, then from the Baker-Hausdorff formula we have exp{B ＋C} ： exp（B ＋ [A, B]} = e^A e^B e^-A. After arranging e^Ae^B = e^B e^A e^W, the disentangling exp{B ＋ C} = e^B e^W is obtained. In this work we use this method to two-mode case, especially, derive the normal ordering form of exp[h（a^＋a ＋ b^＋b） ＋ ga^＋b^＋ ＋ kab] without appealing to Lie algebra method.
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 the Korea government through the Korea institute of Energy Technology Evaluation and Planning(KETEP)The grant number is 20132010101870 for the Promotion of Science
文摘Centrifugal pumps are being widely used in many industrial and commercial applications.Many of these pumps are being operated at constant speed but could provide energy savings through adjustable speed operations.The purpose of this study was to get the energy saving rates of the multistage centrifugal pump with variable speed conditions.For this investigation an experimental set up of variable flow and pressure system was made to get energy saving rates and numerical analyses are applied to validate the pump performance.The energy saving and therefore the cost saving depends on the specific duty cycle of which the machine operates.Duty cycle is the proportion of time during which a component,device and system is operated.The duty cycle segmented into different flow rates and weighting the average value for each segment by the interval time.The system was operated at 50%or less of the pump capacity.The input power of the system was carried out by pump characteristics curve of each operating point.The energy consumption was done by the product of specific duty cycle and the input power of the system for constant speed and variable speed drive operation.The total energy consumed for constant speed drive pump was 75,770 k W.hr and for variable speed drive pump was 31,700 k W.hr.The total energy saving of the system was 44,070 k W.hr or 58.16%annually.So,this paper suggests a method of implementing an energy saving on variable-flow and pressure system of the multistage centrifugal pump.
