A kind of remote ultrasonic generating system is designed in this paper.Microcontroller unit(MCU)Kinetis60and direct digital synthesizer(DDS)AD9951constitute the core section of this ultrasonic generating terminal in ...A kind of remote ultrasonic generating system is designed in this paper.Microcontroller unit(MCU)Kinetis60and direct digital synthesizer(DDS)AD9951constitute the core section of this ultrasonic generating terminal in this system.A friendly and easy-operating host computer software is contrived to control the terminal to generate sinusoidal,rectangular and triangular waveform with variable frequency,amplitude and phase through ZigBee wireless transmission protocol.In order to enhance the practical driving ability,this system also includes power amplifier circuit and transformer matching design,which enable the ultrasonic generating terminal to output enough power for applying to different types of ultrasonic energy convertors.Through experimental verification,the host computer can precisely and swiftly control the ultrasonic generating terminal to generate the above three waveforms with variable wave elements.Oscilloscope is used to verify the terminal output performance of this remote system.展开更多
HCl acid was applied to the surface of the self-prepared Cu-Sn-Pb alloy, and the methods of IR-REF, IR-PAS, XRD, SPM, SEM, TEM and pH were employed to study the forming process and the developing speed of the bronze p...HCl acid was applied to the surface of the self-prepared Cu-Sn-Pb alloy, and the methods of IR-REF, IR-PAS, XRD, SPM, SEM, TEM and pH were employed to study the forming process and the developing speed of the bronze powder-corrosion Cu_2(OH)_3Cl (PC). It is found that the corrosion develops fast in acid environment at room temperature; the corrosion Cu_2(OH)_3Cl with valence Cu^(2+) forms from alloy through the intermediate corrosion CuCl with valence Cu^+; PC is contagious, which can pollute the fresh bronze alloy from the corroded sample by air; when CuCl is oxidized to produce Cu_2(OH)_3Cl, Cu^(2+) cation forms at the same time, and both the oxidizing reactions have zero-order reaction with respect to O_2 in the air; the P1 formation reaction has first-order reaction with respect to Cull; in enormous distilled water Cu_2(OH)_3Cl forms from CuCl through the intermediate product Cu_2O.All the results above are discussed in the present article, and the mechanism of PC formation is studied further. The reaction orders, the rate constants and the apparent activity energies are calculated.展开更多
Following the previous paperr, we examined the kinetics of the irreversible modification of enzyme activity in coupled assay when the modifier reacted with both primary and auxiliary enzymes. It was shown that Tsou’s...Following the previous paperr, we examined the kinetics of the irreversible modification of enzyme activity in coupled assay when the modifier reacted with both primary and auxiliary enzymes. It was shown that Tsou’s kinetic method can also be used in the present situation in some conditions.展开更多
文摘A kind of remote ultrasonic generating system is designed in this paper.Microcontroller unit(MCU)Kinetis60and direct digital synthesizer(DDS)AD9951constitute the core section of this ultrasonic generating terminal in this system.A friendly and easy-operating host computer software is contrived to control the terminal to generate sinusoidal,rectangular and triangular waveform with variable frequency,amplitude and phase through ZigBee wireless transmission protocol.In order to enhance the practical driving ability,this system also includes power amplifier circuit and transformer matching design,which enable the ultrasonic generating terminal to output enough power for applying to different types of ultrasonic energy convertors.Through experimental verification,the host computer can precisely and swiftly control the ultrasonic generating terminal to generate the above three waveforms with variable wave elements.Oscilloscope is used to verify the terminal output performance of this remote system.
基金Project conducted by the Structure Analysis Open Laboratory,USTCsupported by the National Natural Science Foundation of China
文摘HCl acid was applied to the surface of the self-prepared Cu-Sn-Pb alloy, and the methods of IR-REF, IR-PAS, XRD, SPM, SEM, TEM and pH were employed to study the forming process and the developing speed of the bronze powder-corrosion Cu_2(OH)_3Cl (PC). It is found that the corrosion develops fast in acid environment at room temperature; the corrosion Cu_2(OH)_3Cl with valence Cu^(2+) forms from alloy through the intermediate corrosion CuCl with valence Cu^+; PC is contagious, which can pollute the fresh bronze alloy from the corroded sample by air; when CuCl is oxidized to produce Cu_2(OH)_3Cl, Cu^(2+) cation forms at the same time, and both the oxidizing reactions have zero-order reaction with respect to O_2 in the air; the P1 formation reaction has first-order reaction with respect to Cull; in enormous distilled water Cu_2(OH)_3Cl forms from CuCl through the intermediate product Cu_2O.All the results above are discussed in the present article, and the mechanism of PC formation is studied further. The reaction orders, the rate constants and the apparent activity energies are calculated.
文摘Following the previous paperr, we examined the kinetics of the irreversible modification of enzyme activity in coupled assay when the modifier reacted with both primary and auxiliary enzymes. It was shown that Tsou’s kinetic method can also be used in the present situation in some conditions.
