In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinat...In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.展开更多
Herman Melville(1819-1891) is one of the famous writers in the history of American and world literature. Moby Dick is one of the masterpieces of Melville, and it is also his most famous ocean works in his late life. M...Herman Melville(1819-1891) is one of the famous writers in the history of American and world literature. Moby Dick is one of the masterpieces of Melville, and it is also his most famous ocean works in his late life. Moby Dick describes a story on Captain Ahab took revenge on white whale. This paper will discuss Captain Ahab's paranoid personality, and reveal how Melville reflected in the works: coexistence between human and nature. A brief description will be provided for the writer's life and his works, and then I will discuss Captain Ahab's paranoid personality through his whaling capturing process. Then, I will discuss obtaining principles of Captain Ahab, Mate Starbuck, Crew Ishmael, and reveal the Captain's tragic causes and reflected thinking. Finally, I will make a conclusion only if people adopt right obtaining principles to natural resources, could we live with nature altogether.展开更多
In the strap-down TV guidance system, the line-of-sight(LOS) rate can not be obtained frora the measured information, the math platform to select missile attitude information must be set up. The LOS rate selecting m...In the strap-down TV guidance system, the line-of-sight(LOS) rate can not be obtained frora the measured information, the math platform to select missile attitude information must be set up. The LOS rate selecting models based on the missile attitude angle and the rate gyro are set up, the influencing factor and the extracting precision of LOS rate are emulated and analyzed.展开更多
Utilization of the shift operator to represent Euler polynomials as polynomials of Appell type leads directly to its algebraic properties, its relations with powers sums;may be all its relations with Bernoulli polynom...Utilization of the shift operator to represent Euler polynomials as polynomials of Appell type leads directly to its algebraic properties, its relations with powers sums;may be all its relations with Bernoulli polynomials, Bernoulli numbers;its recurrence formulae and a very simple formula for calculating simultaneously Euler numbers and Euler polynomials. The expansions of Euler polynomials into Fourier series are also obtained;the formulae for obtaining all π<sup>m</sup> as series on k<sup>-m</sup> and for expanding functions into series of Euler polynomials.展开更多
“Obtaining” verbs depict a person taking temporary possession of an object. They signal an event of the transferring of one thing from its original owner to a potential possessor. Based on theories of Cognitive Sema...“Obtaining” verbs depict a person taking temporary possession of an object. They signal an event of the transferring of one thing from its original owner to a potential possessor. Based on theories of Cognitive Semantics, this paper intends to probe into the semantic features of English “obtaining” verbs and the different profiles, background frames entailed in different words, hoping to shed light on the further study of the syntactic performance of this category of verbs.展开更多
The degree of polarization (DOP) ellipsoid can be used as either feedback or feedforward signal for automatic polarization mode dispersion compensation. We have realized the experiment for obtaining DOP ellipsoid from...The degree of polarization (DOP) ellipsoid can be used as either feedback or feedforward signal for automatic polarization mode dispersion compensation. We have realized the experiment for obtaining DOP ellipsoid from 100 sampling data of output states of polarization using particle swarm optimization (PSO) as ellipsoid data fitting algorithm. It was shown that the PSO algorithm was powerful for ellipsoid data fitting with high precision within 250 ms.展开更多
In this letter, a thin slab of glass is used as Fabry-Perot etalon inside a cavity of a continuous wave (CW) Nd:YAG laser to change the behavior of its output longitudinal modes. The slab etalon is used as tuning e...In this letter, a thin slab of glass is used as Fabry-Perot etalon inside a cavity of a continuous wave (CW) Nd:YAG laser to change the behavior of its output longitudinal modes. The slab etalon is used as tuning element when it turns around the laser cavity axis. Two simultaneous longitudinal modes with a relatively wide tuning range from 5.83 MHz to 0,02 THz are obtained when the Nd:YAG laser is operated at moderate output power of about 120 roW. The mode structure of this configuration is modeled and simulated. Computer-generated diagrams are also presented schematically and compared with the experimental results.展开更多
In this article the deficiency of "production function method" widely usedin present appraisal of land value in our country is analysed, and the application of theoret-ical method of deriving urban datum lan...In this article the deficiency of "production function method" widely usedin present appraisal of land value in our country is analysed, and the application of theoret-ical method of deriving urban datum land value by "Rent-Profit Ratio Method", whichmight be used for reference in the fields of land administration performed by city govern-ments, the programmes of urban planning formulated by planning departments and fur-ther performing the study of land economics, is proposed.展开更多
A method for the inversion of the transmission losses for the bottom reflection loss is proposed on the basis of the theory of the smooth- averaged sound field. The procedure of the inversion is based on the criterion...A method for the inversion of the transmission losses for the bottom reflection loss is proposed on the basis of the theory of the smooth- averaged sound field. The procedure of the inversion is based on the criterion of the least square error in the transmission losses between calculation and measurement. By using the Gauss - Newton iterative approach, the non - linear least square aloqrithm is equivalent to solving a sequence of lineared least square problems. The physical causes of the instability of the inversion problem are discussed and the stability is improved by means of the Levenberg- Marquardt method. Both numerical simulations with noise and experimental results show that the inversion for the bottom reflection loss of small grazing angle has high precision and the certain perturbation in the measured transmission losses does not lead to serious deviation in the inversion result of the bottom reflection loss.展开更多
This report describes a new method, the self-searching method, to find cigenrays in an ocean where there is a three-dimensional sound speed perturbation blob on a uniform sound speed background. Compared with the trad...This report describes a new method, the self-searching method, to find cigenrays in an ocean where there is a three-dimensional sound speed perturbation blob on a uniform sound speed background. Compared with the traditional shooting method, this method can reduce the number of ray calculations by about two orders of magnitude, and an eigcnray can be found by computer program without manual intervention.展开更多
Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 mm.SHR is one of the mos...Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 mm.SHR is one of the most common convective weather phenomena that can cause severe damage.Short-range forecasting of SHR is an important part of operational severe weather prediction.In the present study,an improved objective SHR forecasting scheme was developed by adopting the ingredients-based methodology and using the fuzzy logic approach.The 1.0°×1.0°National Centers for Environmental Prediction(NCEP)final analysis data and the ordinary rainfall(0.1-19.9 mm h-1)and SHR observational data from 411 stations were used in the improved scheme.The best lifted index,the total precipitable water,the 925 hPa specific humidity(Q 925),and the 925 hPa divergence(DIV 925)were selected as predictors based on objective analysis.Continuously distributed membership functions of predictors were obtained based on relative frequency analysis.The weights of predictors were also objectively determined.Experiments with a typhoon SHR case and a spring SHR case show that the main possible areas could be captured by the improved scheme.Verification of SHR forecasts within 96 hours with NCEP global forecasts 1.0°×1.0°data initiated at 08:00 Beijing Time during the warm seasons in 2015 show the results were improved from both deterministic and probabilistic perspectives.This study provides an objectively feasible choice for short-range guidance forecasts of SHR.The scheme can be applied to other convective phenomena.展开更多
From the hypotheses that the position-representation of a physical state is the Fourier transform of its momentum-representation and that the timerepresentation is the inverse Fourier transform of its energy-represent...From the hypotheses that the position-representation of a physical state is the Fourier transform of its momentum-representation and that the timerepresentation is the inverse Fourier transform of its energy-representation, we are able to obtain the Planck relation E = hν , the de Broglie relation p = h /λ , the Dirac fundamental commutation relation, the Schr?dinger equations, the Heisenberg uncertainty principle in quantum mechanics, and the annihilation/creation of a photon from excitation/de-excitation of an atom following Bohr.展开更多
Studies the stability for them manifold of equilibrium state of the autonomous Birkhoffsystem. Uses the Liapunov's direct method and the first approximation method to obtain thestability criterion for the manifold...Studies the stability for them manifold of equilibrium state of the autonomous Birkhoffsystem. Uses the Liapunov's direct method and the first approximation method to obtain thestability criterion for the manifold of equilibrium state of the system. Gives an example toillustrate the application of the result.展开更多
A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simult...A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.展开更多
Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of ann...Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied.展开更多
Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to...Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one another展开更多
The magnetic properties and microstructure of diffusion annealed [Ta/Nd/NdFeB/Nd/Ta]thin films have been investigated. The films were deposited on Si substrate with various thickness ratio of Nd/NdFeB layer (R=0~3.3)...The magnetic properties and microstructure of diffusion annealed [Ta/Nd/NdFeB/Nd/Ta]thin films have been investigated. The films were deposited on Si substrate with various thickness ratio of Nd/NdFeB layer (R=0~3.3), then diffused and crystallized by annealing at 650℃ for 10 min. The film without Nd layer showed soft magnetic behavior and high content of a-Fe phase. The films with R > =1 showed good hard magnetic properties with the high coercivity of about 20 kOe.展开更多
文摘In this paper, a photoelectric signal obtained scheme via equator triangle pattern engraved on rotor is discussed and the mathematic model is deduced in the case which is deflexion between rotor axis and the coordinate frame of case. The deflexion error and coupling error under the situation are analyzed. Finally, three methods of engraving based on the spherical triangle pattern are presented. The error models of various methods are built up and the simulation curves are provided respectively. We have done the primary experiments on the surface of rotor using this method. It can be seen from the enlarged figures that the rim of the pattern is smooth and the demand of sensor resolution is satisfied by and large. The results of study supply reference for signal obtaining.
文摘Herman Melville(1819-1891) is one of the famous writers in the history of American and world literature. Moby Dick is one of the masterpieces of Melville, and it is also his most famous ocean works in his late life. Moby Dick describes a story on Captain Ahab took revenge on white whale. This paper will discuss Captain Ahab's paranoid personality, and reveal how Melville reflected in the works: coexistence between human and nature. A brief description will be provided for the writer's life and his works, and then I will discuss Captain Ahab's paranoid personality through his whaling capturing process. Then, I will discuss obtaining principles of Captain Ahab, Mate Starbuck, Crew Ishmael, and reveal the Captain's tragic causes and reflected thinking. Finally, I will make a conclusion only if people adopt right obtaining principles to natural resources, could we live with nature altogether.
文摘In the strap-down TV guidance system, the line-of-sight(LOS) rate can not be obtained frora the measured information, the math platform to select missile attitude information must be set up. The LOS rate selecting models based on the missile attitude angle and the rate gyro are set up, the influencing factor and the extracting precision of LOS rate are emulated and analyzed.
文摘Utilization of the shift operator to represent Euler polynomials as polynomials of Appell type leads directly to its algebraic properties, its relations with powers sums;may be all its relations with Bernoulli polynomials, Bernoulli numbers;its recurrence formulae and a very simple formula for calculating simultaneously Euler numbers and Euler polynomials. The expansions of Euler polynomials into Fourier series are also obtained;the formulae for obtaining all π<sup>m</sup> as series on k<sup>-m</sup> and for expanding functions into series of Euler polynomials.
文摘“Obtaining” verbs depict a person taking temporary possession of an object. They signal an event of the transferring of one thing from its original owner to a potential possessor. Based on theories of Cognitive Semantics, this paper intends to probe into the semantic features of English “obtaining” verbs and the different profiles, background frames entailed in different words, hoping to shed light on the further study of the syntactic performance of this category of verbs.
基金This work was supported by the National Natural Science Foundation of China (No. 60072042 and 60377026), the National "863" High Technology Project of China (No. 2001AA122041 and 2003AA311070), and Corporative Building Project of Beijing Educational Committee (No. XK100130437).
文摘The degree of polarization (DOP) ellipsoid can be used as either feedback or feedforward signal for automatic polarization mode dispersion compensation. We have realized the experiment for obtaining DOP ellipsoid from 100 sampling data of output states of polarization using particle swarm optimization (PSO) as ellipsoid data fitting algorithm. It was shown that the PSO algorithm was powerful for ellipsoid data fitting with high precision within 250 ms.
文摘In this letter, a thin slab of glass is used as Fabry-Perot etalon inside a cavity of a continuous wave (CW) Nd:YAG laser to change the behavior of its output longitudinal modes. The slab etalon is used as tuning element when it turns around the laser cavity axis. Two simultaneous longitudinal modes with a relatively wide tuning range from 5.83 MHz to 0,02 THz are obtained when the Nd:YAG laser is operated at moderate output power of about 120 roW. The mode structure of this configuration is modeled and simulated. Computer-generated diagrams are also presented schematically and compared with the experimental results.
文摘In this article the deficiency of "production function method" widely usedin present appraisal of land value in our country is analysed, and the application of theoret-ical method of deriving urban datum land value by "Rent-Profit Ratio Method", whichmight be used for reference in the fields of land administration performed by city govern-ments, the programmes of urban planning formulated by planning departments and fur-ther performing the study of land economics, is proposed.
基金The Project Supported by National Natural Science Fundation of China
文摘A method for the inversion of the transmission losses for the bottom reflection loss is proposed on the basis of the theory of the smooth- averaged sound field. The procedure of the inversion is based on the criterion of the least square error in the transmission losses between calculation and measurement. By using the Gauss - Newton iterative approach, the non - linear least square aloqrithm is equivalent to solving a sequence of lineared least square problems. The physical causes of the instability of the inversion problem are discussed and the stability is improved by means of the Levenberg- Marquardt method. Both numerical simulations with noise and experimental results show that the inversion for the bottom reflection loss of small grazing angle has high precision and the certain perturbation in the measured transmission losses does not lead to serious deviation in the inversion result of the bottom reflection loss.
文摘This report describes a new method, the self-searching method, to find cigenrays in an ocean where there is a three-dimensional sound speed perturbation blob on a uniform sound speed background. Compared with the traditional shooting method, this method can reduce the number of ray calculations by about two orders of magnitude, and an eigcnray can be found by computer program without manual intervention.
基金Key R&D Program of Xizang Autonomous Region(XZ202101ZY0004G)National Natural Science Foundation of China(U2142202)+1 种基金National Key R&D Program of China(2022YFC3004104)Key Innovation Team of China Meteor-ological Administration(CMA2022ZD07)。
文摘Short-duration heavy rainfall(SHR),as delineated by the National Meteorological Center of the China Me-teorological Administration,is characterized by hourly rainfall amounts no less than 20.0 mm.SHR is one of the most common convective weather phenomena that can cause severe damage.Short-range forecasting of SHR is an important part of operational severe weather prediction.In the present study,an improved objective SHR forecasting scheme was developed by adopting the ingredients-based methodology and using the fuzzy logic approach.The 1.0°×1.0°National Centers for Environmental Prediction(NCEP)final analysis data and the ordinary rainfall(0.1-19.9 mm h-1)and SHR observational data from 411 stations were used in the improved scheme.The best lifted index,the total precipitable water,the 925 hPa specific humidity(Q 925),and the 925 hPa divergence(DIV 925)were selected as predictors based on objective analysis.Continuously distributed membership functions of predictors were obtained based on relative frequency analysis.The weights of predictors were also objectively determined.Experiments with a typhoon SHR case and a spring SHR case show that the main possible areas could be captured by the improved scheme.Verification of SHR forecasts within 96 hours with NCEP global forecasts 1.0°×1.0°data initiated at 08:00 Beijing Time during the warm seasons in 2015 show the results were improved from both deterministic and probabilistic perspectives.This study provides an objectively feasible choice for short-range guidance forecasts of SHR.The scheme can be applied to other convective phenomena.
文摘From the hypotheses that the position-representation of a physical state is the Fourier transform of its momentum-representation and that the timerepresentation is the inverse Fourier transform of its energy-representation, we are able to obtain the Planck relation E = hν , the de Broglie relation p = h /λ , the Dirac fundamental commutation relation, the Schr?dinger equations, the Heisenberg uncertainty principle in quantum mechanics, and the annihilation/creation of a photon from excitation/de-excitation of an atom following Bohr.
文摘Studies the stability for them manifold of equilibrium state of the autonomous Birkhoffsystem. Uses the Liapunov's direct method and the first approximation method to obtain thestability criterion for the manifold of equilibrium state of the system. Gives an example toillustrate the application of the result.
文摘A design for an air-cooled test tube, with a series of modular and movable rings (cylindrical “crystallization comb”), installed in a laboratory crucible furnace is presented. The setup allows easy regulation simultaneous crystallization tests of a series of different crystallization rates in several columns (matrix) of test tubes, enabling fast studies of obtaining crystals. This low-budget, portable device (i.e. adjustable airstream with more simple control options), can also be applied in tube and chamber furnaces. The relations between the crystallization rate and parameters of air-cooled test tube are given and numerically analyzed.
文摘Silver-ceramics (Ag2MO2)(M=Co, Ni, or Cu) were prepared through thermal decompositionof coprecipitated oxalates. Pellets of these materials were annealed at 350℃ for different timeperiods up to 5 h. The effect of annealing time on the transport properties was studied. IR andX-ray spectra were also studied.
文摘Wollastonite, a mineral of wide industrial applications was synthesised from rice husk ash silica and limestone. A number of raw batches consisting of these starting materials, in 1:1 molar ratio, were heat treated to produce it through solid state reaction from 900℃ to 1300℃. The conducted reaction was monitored by XRD step by step. Amount of Wollastonite formed at every temperature was also studied to some extent. Analyses of the obtained data indicated that the target mineral formation was quite effective and almost proportional to a rise in temperature up to 1200℃. The results from both, XRD and chemical analysis were found in fair agreement with one another
文摘The magnetic properties and microstructure of diffusion annealed [Ta/Nd/NdFeB/Nd/Ta]thin films have been investigated. The films were deposited on Si substrate with various thickness ratio of Nd/NdFeB layer (R=0~3.3), then diffused and crystallized by annealing at 650℃ for 10 min. The film without Nd layer showed soft magnetic behavior and high content of a-Fe phase. The films with R > =1 showed good hard magnetic properties with the high coercivity of about 20 kOe.