The paper revealed the place and role of Russia in the global market of platinum metals, highlighted features of pricing in the export of Russian platinum group metals, the main problems of pricing in the export contr...The paper revealed the place and role of Russia in the global market of platinum metals, highlighted features of pricing in the export of Russian platinum group metals, the main problems of pricing in the export contracts related to the instability of markets and imperfect currency and customs legislation of the Russian Federation, proposed innovative ways to solutions to existing problems in the preparation and conclusion of export contracts.展开更多
We report the transient effects in Erbium Doped Fiber Amplifier(EDFA)systems for pulsed signals with different duty-cycles.The work includes the analysis using three different duty-cycles,10%,20%and 50%.A curve fittin...We report the transient effects in Erbium Doped Fiber Amplifier(EDFA)systems for pulsed signals with different duty-cycles.The work includes the analysis using three different duty-cycles,10%,20%and 50%.A curve fitting technique is also proposed to predict the transients of any lesser duty-cycled pulse,once the transients of a larger duty-cycled pulse is known.Mathematical evaluation confirms the double exponential shape of transient distorted signal.Further,EDFA transient effect is experimentally verified on a Wavelength Division Multiplexed(WDM)link by multiplexing high and low bitrate modulated optical signals.We conclude the paper by proposing a transient suppression technique for variable dutycycle signals and analyzing its effectiveness with different wavelength spacing.展开更多
This paper presents a new AC chopper voltage conditioner, which can generate high quality sinusoidal waveforms with adjustable amplitudes. The circuit structure, operation principle, and control mode are analyzed in d...This paper presents a new AC chopper voltage conditioner, which can generate high quality sinusoidal waveforms with adjustable amplitudes. The circuit structure, operation principle, and control mode are analyzed in detail, the system essentially consisting of an equal duty cycle modulation AC voltage buck chopper and a voltage polarity change H-bridge, a full-wave rectifier, to perform tightly closed-loop control of the AC chopper voltage condtioner, a digital controller on a new converter model has been developed. The controller has very well dynamic response. To evaluate the new circuit and proposed control scheme, a 5kW conditioner is developed and the experimental results demonstrate that the system has good performances.展开更多
文摘The paper revealed the place and role of Russia in the global market of platinum metals, highlighted features of pricing in the export of Russian platinum group metals, the main problems of pricing in the export contracts related to the instability of markets and imperfect currency and customs legislation of the Russian Federation, proposed innovative ways to solutions to existing problems in the preparation and conclusion of export contracts.
文摘We report the transient effects in Erbium Doped Fiber Amplifier(EDFA)systems for pulsed signals with different duty-cycles.The work includes the analysis using three different duty-cycles,10%,20%and 50%.A curve fitting technique is also proposed to predict the transients of any lesser duty-cycled pulse,once the transients of a larger duty-cycled pulse is known.Mathematical evaluation confirms the double exponential shape of transient distorted signal.Further,EDFA transient effect is experimentally verified on a Wavelength Division Multiplexed(WDM)link by multiplexing high and low bitrate modulated optical signals.We conclude the paper by proposing a transient suppression technique for variable dutycycle signals and analyzing its effectiveness with different wavelength spacing.
文摘This paper presents a new AC chopper voltage conditioner, which can generate high quality sinusoidal waveforms with adjustable amplitudes. The circuit structure, operation principle, and control mode are analyzed in detail, the system essentially consisting of an equal duty cycle modulation AC voltage buck chopper and a voltage polarity change H-bridge, a full-wave rectifier, to perform tightly closed-loop control of the AC chopper voltage condtioner, a digital controller on a new converter model has been developed. The controller has very well dynamic response. To evaluate the new circuit and proposed control scheme, a 5kW conditioner is developed and the experimental results demonstrate that the system has good performances.
