This paper is devoted to characterizing the Riemann-Stieltjes operators and pointwise multipliers on F（p, q, s） spaces in the unit ball of C^n which contain many classical function spaces, such as the Bloch space, B...This paper is devoted to characterizing the Riemann-Stieltjes operators and pointwise multipliers on F（p, q, s） spaces in the unit ball of C^n which contain many classical function spaces, such as the Bloch space, BMOA and Q8 spaces. The boundedness and compactness of these operators on F（p, q, s） spaces are characterized by means of an embedding theorem, i.e., F（p,q, s） spaces boundedly embedded into the tent-type spaces Tp,s^∞（μ）展开更多
The titl angle measurement system based on the ADXL345 of three-axis acceleration sensor is introduced, and the composition and working principle of the system are described. The MSP430F149 microcontroller of ultra-lo...The titl angle measurement system based on the ADXL345 of three-axis acceleration sensor is introduced, and the composition and working principle of the system are described. The MSP430F149 microcontroller of ultra-low power and high performance is adopted. Firstly, the voltage value which is proportional to the acceleration value is output by ADXL345 when the system is powered. Secondly, the voltage value is converted into the corresponding digital signal by AD converter of the sensor. Thirdly, the digital signal is transformed into the titl angle according to the arithmetic processing of the MSP430F149. Finally, the corresponding angle is displayed on the liquid crystal display （LCD） screen. Experimental results show that the design has high sensitivity and response speed compared with the conventional methods. It is suitable for practical engineering application because of simple structure, low cost and low power consumption.展开更多
By employing function one-direction S-rough sets and rough law generation method based on function S-rough sets, ^-f-decomposition law and ^-F-decomposition rough law are proposed, and the measurement of rough law var...By employing function one-direction S-rough sets and rough law generation method based on function S-rough sets, ^-f-decomposition law and ^-F-decomposition rough law are proposed, and the measurement of rough law variation in the process of rough law ^-F-decomposition is researched. The concepts of law energy and attdbute ^-f-interference degree are presented, which make the variation of rough law become measurable. ^-f-decomposition law energy characteristic theorem, ^-f- decomposition law energy inequality theorem, ^-F-decomposition rough law energy characteristic theorem, and ^-f-decomposition law energy mean value theorem are presented.展开更多
The status and the variation of electrical resistance of impacted carbon fiber/epoxy-matrix composites were studied by ultrasonic F-scan and electrical resistance measurement The experimental results shows that impact...The status and the variation of electrical resistance of impacted carbon fiber/epoxy-matrix composites were studied by ultrasonic F-scan and electrical resistance measurement The experimental results shows that impact damage energy threshold value of carbon fabric/epoxy-matrix composites can determine by using ultrasonic F-scan. When the impact energy exceeds the threshold value, damage is generated in composites. Electrical resistance of impacted composites is changed owing to the contact of each carbon fiber unit in composites, which cause a change of the series-parallel in conductors. The veracity of detecting impact damage in composites can be improved in this case.展开更多
Purpose： In this contribution we continue our investigations related to the activity index （A/） and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Desig...Purpose： In this contribution we continue our investigations related to the activity index （A/） and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Design/methodology/approach： We point out that fluctuations in the value of the AI for a given country and domain are never the result of that country＇s policy with respect to that domain alone because there are exogenous factors at play. For this reason we introduce the F-measure. This F-measure is nothing but the harmonic mean of the country＇s share in the world＇s publication output in the given domain and the given domain＇s share in the country＇s publication output.Findings： The F-measure does not suffer from the problems the AI does Research limitations： The indicator is not yet fully tested in real cases R＆D policy management： In policy considerations, the AI should better be replaced by the F-measure as this measure can better show the results of science policy measures （which the AI cannot as it depends on exogenous factors）. Originality/value： We provide an original solution for a problem that is not fully realized by policy makers.展开更多
The absolute frequency of 87Rb 5S1/2 （F=2）→5D5/2 （F＂ = 4） two-photon transition at 778nm is measured in an accuracy of 44kHz. A home-made erbium-doped fiber laser frequency comb with frequency stability of 5.0 ...The absolute frequency of 87Rb 5S1/2 （F=2）→5D5/2 （F＂ = 4） two-photon transition at 778nm is measured in an accuracy of 44kHz. A home-made erbium-doped fiber laser frequency comb with frequency stability of 5.0 × 10-13@1 s is employed for the light source. By using a periodically poled lithium niobate, the femtosecond pulse operating in 1556 nm is frequency-doubled to 778 nm to obtain the direct two-photon transition spectroscopy of thermal rubidium vapor. Through sweeping the carrier envelope offset frequency （fceo）, the 5S1/2 （F=2）→5D5/2 （F＂ = 4） two-photon transition line is clearly resolved and its absolute frequency is determined via the peak-finding of the fitting curve. After the frequency correction, the measured result agrees well with the previous experiment on this transition. The entire potential candidate of optical frequency standard for system configuration is compact and robust, providing a telecommunication applications.展开更多
研究基于STM32F4微控制器的无刷直流电机滑模速度控制策略,实现一种比传统控制系统(proportional integral derivative,PID)更优的速度方法,提高电机控制的响应速度和稳定性。控制策略采用滑模控制理论设计了一套完整的控制算法,并通过S...研究基于STM32F4微控制器的无刷直流电机滑模速度控制策略,实现一种比传统控制系统(proportional integral derivative,PID)更优的速度方法,提高电机控制的响应速度和稳定性。控制策略采用滑模控制理论设计了一套完整的控制算法,并通过STM32F4微控制器实施。实验结果显示,滑模控制在动态性能和抗扰动性方面均超越了PID控制,展现了较好的控制效果。该研究不仅证实了滑模控制在无刷电机速度控制中的应用价值,也展示了STM32F4在实现复杂控制策略方面的强大能力,对工业自动化和相关领域有着重要的实际意义。展开更多
基金Supported in part by the National Natural Science Foundation of China(11271359)the Fundamental Research Funds for the Central Universities(2014-Ia-037and 2015-IVA-069)
文摘This paper is devoted to characterizing the Riemann-Stieltjes operators and pointwise multipliers on F（p, q, s） spaces in the unit ball of C^n which contain many classical function spaces, such as the Bloch space, BMOA and Q8 spaces. The boundedness and compactness of these operators on F（p, q, s） spaces are characterized by means of an embedding theorem, i.e., F（p,q, s） spaces boundedly embedded into the tent-type spaces Tp,s^∞（μ）
文摘The titl angle measurement system based on the ADXL345 of three-axis acceleration sensor is introduced, and the composition and working principle of the system are described. The MSP430F149 microcontroller of ultra-low power and high performance is adopted. Firstly, the voltage value which is proportional to the acceleration value is output by ADXL345 when the system is powered. Secondly, the voltage value is converted into the corresponding digital signal by AD converter of the sensor. Thirdly, the digital signal is transformed into the titl angle according to the arithmetic processing of the MSP430F149. Finally, the corresponding angle is displayed on the liquid crystal display （LCD） screen. Experimental results show that the design has high sensitivity and response speed compared with the conventional methods. It is suitable for practical engineering application because of simple structure, low cost and low power consumption.
基金supported by the Natural Science Foundation of Shandong Province (Y2007H02)
文摘By employing function one-direction S-rough sets and rough law generation method based on function S-rough sets, ^-f-decomposition law and ^-F-decomposition rough law are proposed, and the measurement of rough law variation in the process of rough law ^-F-decomposition is researched. The concepts of law energy and attdbute ^-f-interference degree are presented, which make the variation of rough law become measurable. ^-f-decomposition law energy characteristic theorem, ^-f- decomposition law energy inequality theorem, ^-F-decomposition rough law energy characteristic theorem, and ^-f-decomposition law energy mean value theorem are presented.
基金Funded by the Key Laboratory of Nondestructive Testing (Nanchang Hangkong University), Ministry of Education, China(No.ZD200829001)
文摘The status and the variation of electrical resistance of impacted carbon fiber/epoxy-matrix composites were studied by ultrasonic F-scan and electrical resistance measurement The experimental results shows that impact damage energy threshold value of carbon fabric/epoxy-matrix composites can determine by using ultrasonic F-scan. When the impact energy exceeds the threshold value, damage is generated in composites. Electrical resistance of impacted composites is changed owing to the contact of each carbon fiber unit in composites, which cause a change of the series-parallel in conductors. The veracity of detecting impact damage in composites can be improved in this case.
文摘Purpose： In this contribution we continue our investigations related to the activity index （A/） and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Design/methodology/approach： We point out that fluctuations in the value of the AI for a given country and domain are never the result of that country＇s policy with respect to that domain alone because there are exogenous factors at play. For this reason we introduce the F-measure. This F-measure is nothing but the harmonic mean of the country＇s share in the world＇s publication output in the given domain and the given domain＇s share in the country＇s publication output.Findings： The F-measure does not suffer from the problems the AI does Research limitations： The indicator is not yet fully tested in real cases R＆D policy management： In policy considerations, the AI should better be replaced by the F-measure as this measure can better show the results of science policy measures （which the AI cannot as it depends on exogenous factors）. Originality/value： We provide an original solution for a problem that is not fully realized by policy makers.
基金Supported by the National Natural Science Foundation of China under Grant Nos 61405002,91336103,10934010,61535001 and 61078026
文摘The absolute frequency of 87Rb 5S1/2 （F=2）→5D5/2 （F＂ = 4） two-photon transition at 778nm is measured in an accuracy of 44kHz. A home-made erbium-doped fiber laser frequency comb with frequency stability of 5.0 × 10-13@1 s is employed for the light source. By using a periodically poled lithium niobate, the femtosecond pulse operating in 1556 nm is frequency-doubled to 778 nm to obtain the direct two-photon transition spectroscopy of thermal rubidium vapor. Through sweeping the carrier envelope offset frequency （fceo）, the 5S1/2 （F=2）→5D5/2 （F＂ = 4） two-photon transition line is clearly resolved and its absolute frequency is determined via the peak-finding of the fitting curve. After the frequency correction, the measured result agrees well with the previous experiment on this transition. The entire potential candidate of optical frequency standard for system configuration is compact and robust, providing a telecommunication applications.
文摘研究基于STM32F4微控制器的无刷直流电机滑模速度控制策略,实现一种比传统控制系统(proportional integral derivative,PID)更优的速度方法,提高电机控制的响应速度和稳定性。控制策略采用滑模控制理论设计了一套完整的控制算法,并通过STM32F4微控制器实施。实验结果显示,滑模控制在动态性能和抗扰动性方面均超越了PID控制,展现了较好的控制效果。该研究不仅证实了滑模控制在无刷电机速度控制中的应用价值,也展示了STM32F4在实现复杂控制策略方面的强大能力,对工业自动化和相关领域有着重要的实际意义。
