Organic photovoltaic(OPV)cells have been thoroughly investigated in the past decade owing to the advantages of low cost,flexibility,light weight,easy fabrication,semi-transparency and colorfulness,*** the efficiency o...
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Organic photovoltaic(OPV)cells have been thoroughly investigated in the past decade owing to the advantages of low cost,flexibility,light weight,easy fabrication,semi-transparency and colorfulness,*** the efficiency of bulk heterojunction OPVs is still limited due to the
Flow control valve generally consists of constant pressure difference reducing valve and throttle *** it works under the condition of high differential pressure and flow, the pressure loss of reducing valve in-stalled...
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Flow control valve generally consists of constant pressure difference reducing valve and throttle *** it works under the condition of high differential pressure and flow, the pressure loss of reducing valve in-stalled in main loop will get increased and the hydraulic oil temperature will be increased as well. A digital pilotflow control valve is studied in this paper. The main stage is a cartridge valve based on the flow amplifying princi-ple. The pilot stage is digital flow control valve which consists of digital valve and constant pressure difference re-ducing valve. The digital valve controlled by PWM signal has some characteristics such as less throttling loss andgood repeatability. The high pressure loss and hydraulic oil temperature will be effectively reduced by using con-stant pressure difference reducing valve in the small flow pilot circuit. Through theoretical derivation and simula-tion research, the feasibility of this valve is verified, and some conclusions are drawn for the relationships betweenthe performance and structure parameters, which provides theoretical basis for their design.
Multiwavelength Brillouin Erbium fiber laser with ultra-narrow bandwidth filter is used as a temperature sensor. It has less than 10~(-3) ℃ resolution at the 3rd-order Stokes in the short term. 3.104 MHz/℃ sensitivi...
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ISBN:
(纸本)9781509062904
Multiwavelength Brillouin Erbium fiber laser with ultra-narrow bandwidth filter is used as a temperature sensor. It has less than 10~(-3) ℃ resolution at the 3rd-order Stokes in the short term. 3.104 MHz/℃ sensitivity of the 3rd-order Stokes wavelength are demonstrated, which is three times that of the 1st-order Stokes wavelength. A less than 0.2 ℃ temperature error is obtained for every Stokes wavelength. This proposal can provide a feasible temperature sensing scheme with high sensitivity, high precision and low frequency detection.
An ultra-wideband direct chaotic through-wall imaging radar is proposed and experimentally demonstrated. The chaotic signal is generated by an improved Colpitis oscillator. Target range information is achieved by the ...
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ISBN:
(纸本)9781785610387
An ultra-wideband direct chaotic through-wall imaging radar is proposed and experimentally demonstrated. The chaotic signal is generated by an improved Colpitis oscillator. Target range information is achieved by the cross-correlation between the time-delayed reflected echo signal and the replica of the transmitted chaotic signal. Two-dimensional image is obtained by synthetic aperture technology and back projection algorithm. Experimental results of single target and double targets show that the proposed chaotic radar system can through 20cm thick wall to detect and locate the target.
Due to the distinguished properties offered by different structural phases of monolayer MoS2, phase engineering design are urgently required for achieving switchable structural phase. Strain engineering is widely acce...
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Solution of the practical problems of the ice engineering requires the data about the strength of the ice cover that depends upon its temperature. In most cases, the snow lies on the ice cover and the ice temperature ...
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Solution of the practical problems of the ice engineering requires the data about the strength of the ice cover that depends upon its temperature. In most cases, the snow lies on the ice cover and the ice temperature differs from the atmospheric air temperature. To reveal the correlation of the air temperature with temperature on interfaces air-snow and snow-ice, the known in the thermophysics solution of the problem of the heat transfer through the multilayer plate was applied. Derived solution connects the temperature of air and temperature on the snow-ice interface and satisfactory correlates with data of the field measurements of the temperature within snow layer and ice cover and ice thickness on the Heilongjiang (Amur) River. Results of investigation are recommended for the ice temperature evaluation in engineering practice.
Dispersions of individual carbon nanotubes (CNTs) are crucial for nanodevices and polymer/CNTs nanocomposites. In this paper, stable and homogenous dispersions of individual multiwalled carbon nanotubes (MWCNTs) have ...
Dispersions of individual carbon nanotubes (CNTs) are crucial for nanodevices and polymer/CNTs nanocomposites. In this paper, stable and homogenous dispersions of individual multiwalled carbon nanotubes (MWCNTs) have been synthesized. The factors influencing the dispersibility mechanism, including the surfactant concentration and the pH value, have been investigated. SEM images display the impurities sticking on MWCNTs which have been removed. The oxygen-containing groups on the surface of MWCNTs sample have been detected through FT-IR and Raman spectra. All experimental results illustrate that using fullerenols as surfactant can greatly improve the dispersibility of MWCNTs. Moreover, the prepared dispersions exhibit good stability that the sediment percentage of fullerenols-MWCNTs is only 5.2% after 5 days.
We propose and demonstrate a scheme to measure the distribution of temperature along an optical fiber based on pseudo-random sequence modulation. In our experimental work, current modulation with a pseudo-random bit s...
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We propose and demonstrate a scheme to measure the distribution of temperature along an optical fiber based on pseudo-random sequence modulation. In our experimental work, current modulation with a pseudo-random bit sequence (PRBS) is applied to a laser diode that serves as the Brillouin pump light and reference light. Because of the independence of the spatial resolution on the PRBS length~ the measurement range can be extended while maintaining high spatial resolution using a long PRBS length. Temperature-induced changes in a Brillouin frequency shift of 250 m fiber sections are clearly observed with 54 cm spatial resolution by this method.
An ultra-wideband direct chaotic through-wall imaging radar is proposed and experimentally demonstrated. The chaotic signal is generated by an improved Colpitts oscillator. Target range information is achieved by the ...
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ISBN:
(纸本)9781510822023
An ultra-wideband direct chaotic through-wall imaging radar is proposed and experimentally demonstrated. The chaotic signal is generated by an improved Colpitts oscillator. Target range information is achieved by the cross-correlation between the time-delayed reflected echo signal and the replica of the transmitted chaotic signal. Two-dimensional image is obtained by synthetic aperture technology and back projection algorithm. Experimental results of single target and double targets show that the proposed chaotic radar system can through 20cm thick wall to detect and locate the target.
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