The sub-Doppler absorption laser spectroscopy at 728nm transition from the 5D5/2 state to the 6F state of cesium with linewidth near 10 MHz is first experimentally performed with indirect pumping from the ground state...The sub-Doppler absorption laser spectroscopy at 728nm transition from the 5D5/2 state to the 6F state of cesium with linewidth near 10 MHz is first experimentally performed with indirect pumping from the ground state 6S1/2 to the state 7P3/2 by a 455.5nm diode laser. Using a 455.5nm diode laser as an indirect pump laser, several excited states will be populated due to spontaneous decay from the 7P state. We first implement the sub-Doppler absorption laser spectroscopy at 728nm from the 5D5/2 state to the 6F state when Cs atoms within thermal glass cell decay to the 5D5/2 state. Due to velocity transfer effect, the hyperfine structure of 5D5/2 shows a mixed and complicated pattern but very e/ear structure when the 455.5nm pumping laser is counter-propagating (or co-propagating) with the 728nm probing laser.展开更多
An ion chromatography method has been proposed for the determination of three common inorganic anions(chloride,nitrate and sulfate) in anionic surfactants using a single pump system.The new system consists of an ion...An ion chromatography method has been proposed for the determination of three common inorganic anions(chloride,nitrate and sulfate) in anionic surfactants using a single pump system.The new system consists of an ion exclusion column,a concentrator column,and an anion exchange column connected in series via two 6-ports valves in a Dionex ICS-2000 ion chromatograph.The valves were switched several times for removing surfactants,concentrating and separating the three anions.The chromatographic conditions were optimized.Detection limits(S/N = 3) were in the range of 0.10-0.68μg/L.The relative standard deviations(RSDs) of peak area were less than 4.6%.The recoveries were in the range of 84.1-112.6%.展开更多
The disc-seal single screw pump(DSSP)used in the field of high viscosity oily sludge transport has a huge advantage.However,there is no research on the pressurization characteristics of the DSSP at present,which makes...The disc-seal single screw pump(DSSP)used in the field of high viscosity oily sludge transport has a huge advantage.However,there is no research on the pressurization characteristics of the DSSP at present,which makes its application limited.In view of this,the pressurization process mathematical model of the DSSP was established based on the geometric model of the pump.By using this model,the pressurization characteristics of DSSP and the influence of working parameters on the pressurization process were studied combined with the principle of back-flow pressurization.Analysis results show that the instantaneous pressurization process could be realized mainly depending on the reflux pressurization from the outlet chamber to the pressurization chamber when the screw rotor rotating angle is located at-5°to+5°.The pressure in the pressurization chamber will increase with the increase of working parameters which include inlet pressure,outlet pressure,screw rotation velocity and dynamic viscosity of fluid medium in the area of flow-back pressurization.The screw rotation velocity and the viscosity of the conveying medium have significant effects on the peak pressure in the pressurization chamber,and the peak pressure in the pressurization chamber is proportional to the screw rotation velocity and the dynamic viscosity coefficient of the conveying medium.The proportional coefficient between the peak pressure and the screw rotation velocity is 6.29×10~4.The proportional coefficient between the peak pressure and the dynamic viscosity of the conveying medium is 6.28×10~6.展开更多
Supercontinuum generation(SC) of more than one octave spectrum spanning covering from 400 nm to 820 nm was achieved by pumping a piece of aluminum nitride(AIN) single crystal using a nanosecond 355 nm ultraviolet ...Supercontinuum generation(SC) of more than one octave spectrum spanning covering from 400 nm to 820 nm was achieved by pumping a piece of aluminum nitride(AIN) single crystal using a nanosecond 355 nm ultraviolet laser. The AlN with a thickness of ~0.8 mm was grown by an optimized physical vapor transport technique and polished with solidification technology. Compared to previously reported ones, the achieved visible SC exhibited the broadest spectrum spanning from bulk materials pumped by a nanosecond pulse laser. The visible supercontinuum in Al N presents new opportunities for bulk material-based white light SC and may find more potential applications beyond typical applications in integrated semiconductive photoelectronic devices.展开更多
With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving...With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving operation of large thermal power units has become the norm. When the depth of the unit reaches a lower load, the once-through boiler changes from dry to wet operation, and the water separated from the boiler steam-water separator directly enters the condenser or is discharged through the blowdown system, resulting in a large amount of discharge and heat loss. As a result, the operating economy of the unit decreased significantly.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 91436210
文摘The sub-Doppler absorption laser spectroscopy at 728nm transition from the 5D5/2 state to the 6F state of cesium with linewidth near 10 MHz is first experimentally performed with indirect pumping from the ground state 6S1/2 to the state 7P3/2 by a 455.5nm diode laser. Using a 455.5nm diode laser as an indirect pump laser, several excited states will be populated due to spontaneous decay from the 7P state. We first implement the sub-Doppler absorption laser spectroscopy at 728nm from the 5D5/2 state to the 6F state when Cs atoms within thermal glass cell decay to the 5D5/2 state. Due to velocity transfer effect, the hyperfine structure of 5D5/2 shows a mixed and complicated pattern but very e/ear structure when the 455.5nm pumping laser is counter-propagating (or co-propagating) with the 728nm probing laser.
基金supported by the National Natural Science Foundation of China(Nos.20775070 and J0830413)Zhejiang Provincial Natural Science Foundation of China(Nos.R4080124 and J20091495)
文摘An ion chromatography method has been proposed for the determination of three common inorganic anions(chloride,nitrate and sulfate) in anionic surfactants using a single pump system.The new system consists of an ion exclusion column,a concentrator column,and an anion exchange column connected in series via two 6-ports valves in a Dionex ICS-2000 ion chromatograph.The valves were switched several times for removing surfactants,concentrating and separating the three anions.The chromatographic conditions were optimized.Detection limits(S/N = 3) were in the range of 0.10-0.68μg/L.The relative standard deviations(RSDs) of peak area were less than 4.6%.The recoveries were in the range of 84.1-112.6%.
基金supported by National Key R&D Program of China[NO.2020YFB2010002]National Natural Science Foundation of China[NO.51706247,NO.51975585]the Fundamental Research Funds for the Central Universities and the Opening Fund of National Engineering Laboratory of Offshore Geophysical and Exploration Equipment[NO.20CX02312A]
文摘The disc-seal single screw pump(DSSP)used in the field of high viscosity oily sludge transport has a huge advantage.However,there is no research on the pressurization characteristics of the DSSP at present,which makes its application limited.In view of this,the pressurization process mathematical model of the DSSP was established based on the geometric model of the pump.By using this model,the pressurization characteristics of DSSP and the influence of working parameters on the pressurization process were studied combined with the principle of back-flow pressurization.Analysis results show that the instantaneous pressurization process could be realized mainly depending on the reflux pressurization from the outlet chamber to the pressurization chamber when the screw rotor rotating angle is located at-5°to+5°.The pressure in the pressurization chamber will increase with the increase of working parameters which include inlet pressure,outlet pressure,screw rotation velocity and dynamic viscosity of fluid medium in the area of flow-back pressurization.The screw rotation velocity and the viscosity of the conveying medium have significant effects on the peak pressure in the pressurization chamber,and the peak pressure in the pressurization chamber is proportional to the screw rotation velocity and the dynamic viscosity coefficient of the conveying medium.The proportional coefficient between the peak pressure and the screw rotation velocity is 6.29×10~4.The proportional coefficient between the peak pressure and the dynamic viscosity of the conveying medium is 6.28×10~6.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.61575129 and 11447029)the Science&Technology Innovation Committee Foundation of Shenzhen(No.JCYJ20160328144942069)
文摘Supercontinuum generation(SC) of more than one octave spectrum spanning covering from 400 nm to 820 nm was achieved by pumping a piece of aluminum nitride(AIN) single crystal using a nanosecond 355 nm ultraviolet laser. The AlN with a thickness of ~0.8 mm was grown by an optimized physical vapor transport technique and polished with solidification technology. Compared to previously reported ones, the achieved visible SC exhibited the broadest spectrum spanning from bulk materials pumped by a nanosecond pulse laser. The visible supercontinuum in Al N presents new opportunities for bulk material-based white light SC and may find more potential applications beyond typical applications in integrated semiconductive photoelectronic devices.
文摘With the rapid development of the installed capacity of clean energy sources such as wind power, hydropower and photovoltaic, significant changes have taken place in the domestic power structure, and deep peak-shaving operation of large thermal power units has become the norm. When the depth of the unit reaches a lower load, the once-through boiler changes from dry to wet operation, and the water separated from the boiler steam-water separator directly enters the condenser or is discharged through the blowdown system, resulting in a large amount of discharge and heat loss. As a result, the operating economy of the unit decreased significantly.