We extend the method that Banerjee and Majhi have used to discuss Hawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the ...We extend the method that Banerjee and Majhi have used to discuss Hawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the charged black hole by a new Tortoise coordinate transformation. Taking the reaction of the radiation of the particle to the spacetime into consideration, we not only derive the radiation spectrum that satisfies the unitary principle in quantum mechanics but also show that the contribution of ingoing particles is equal to the one of outgoing particles on the similar chemical potential term in radiation spectrum caused by charged particles.展开更多
To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum...To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.展开更多
Based on the theory of plasma continuous radiation, the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained. During the development...Based on the theory of plasma continuous radiation, the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained. During the development process of a return stroke of ground flash, the intensity of continuous radiation spectrum is separated on the basis of the spectrums with obviously different luminous intensity at two moments. The electron temperature of the lightning discharge channel is obtained through the curve fitting of the continuous spectrum intensity. It is found that electron temperature increases with the increase of wavelength and begins to reduce after the peak. The peak temperature of the two spectra is close to 25 000 K. To be compared with the result of discrete spectrum, the electron temperature is fitted by the O I line and N II line of the spectrum respectively. The comparison shows that the high temperature value is in good agreement with the temperature of the lightning core current channel obtained from the ion line information, and the low temperature at the high band closes to the calculation result of the atomic line, at a low band is lower than the calculation of the atomic line, which reflects the temperature of the luminous channel of the outer corona.展开更多
Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, t...Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, the solar spectrum data measured by Kondratyev lead to a value of at least 7134 K. Such a higher value can be obtained by interpreting the Planck formula for the black radiation spectrum for the Kondratyev data. In addition, using the Stefan-Boltzmann law, the energetic emissivity of the Sun’s surface was determined to be 0.431. Furthermore, based on Petela’s formulae for exergy of thermal radiation, the exergetic emissivity of the Sun’s surface was also calculated at the level of 0.426.展开更多
OBJECTIVE:To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan(LU 9) acupoint in patients with asthma.METHODS:A highly sensitive infrared spectrum d...OBJECTIVE:To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan(LU 9) acupoint in patients with asthma.METHODS:A highly sensitive infrared spectrum detecting device was used to detect the spectrums of spontaneous infrared radiation at Taiyuan(LU 9) in 37 asthma patients and 34 healthy volunteers.RESULTS:Asthma patients had significantly lower infrared intensity than that of the healthy volunteers(P>0.01).Asthma patients had significantly lower overall infrared radiation intensity at the left Taiyuan(LU 9) than that of healthy volunteers(P>0.05),but there was no significant difference between healthy volunteers and asthma patients at the right Taiyuan(LU 9)(P>0.05).The infrared radiation intensity of 17 wavelength spots at the left Taiyuan(LU 9) and 4 wavelength spots at the right Taiyuan(LU 9) in asthma patients were significantly lower than those of healthy volunteers(P>0.05).At 2 μm,the infrared radiation intensity of asthma patients was significantly stronger than that of healthy volunteers(P>0.05).At 19 wavelength spots in the healthy volunteers and at 4 wavelength spots in the asthma patients,the left Taiyuan(LU 9) showed a significantly stronger intensity than that of the right Taiyuan(LU 9)(P>0.05).By Pearson's χ2 test,healthy volunteers had more wavelength spots that were significantly different between the left and right Taiyuan(LU 9) than the asthma patients(P>0.01).CONCLUSION:Changes in the infrared spectrum at the Taiyuan(LU 9) acupoint in asthma patients may reflect distinct pathological changes.Certain acupuncture points may be related to specific organs.展开更多
With the most advanced Synchronous Radiation Photoelectron Spectrum(SRPS),the emission mechanism of M-type cathodes has been investigated from the perspective of chemical state.Based on the experimental results of SRP...With the most advanced Synchronous Radiation Photoelectron Spectrum(SRPS),the emission mechanism of M-type cathodes has been investigated from the perspective of chemical state.Based on the experimental results of SRPS analysis,a new model of the electron emission mechanism for M-type cathode is discussed.The main topics in this paper include the research status of electron emission mechanism of M-type cathodes;the advantages of SRPS technology;the distribution of oxygen chemical state on the cathode surface and the evolvement of oxygen chemical state during activation process;the relation between barium chemical state and osmium(Os)-coating;surplus barium and its formula;the characteristics of Os,and other noble metal coatings;the relation between film characteristics and emission performance of cathodes,the inhibition effects to the emission for Platinum(Pt)-coated cathode,etc.At the end of this paper,electron emission mechanism of M-type cathode is summarized and foreseen.展开更多
Extending Parikh and Wilczek's work to the non-stationary black hole, we study the Hawking radiation of the non-stationary Kerr black hole by the Hamilto-Jacobi method. The result shows that the radiation spectrum is...Extending Parikh and Wilczek's work to the non-stationary black hole, we study the Hawking radiation of the non-stationary Kerr black hole by the Hamilto-Jacobi method. The result shows that the radiation spectrum is not purely thermal and the tunnelling probability is related to the change of Bekenstein Hawking entropy, which gives a correction to the Hawking thermal radiation of the black hole.展开更多
A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation emitted by positrons moving towards the surface of the neutron star along inclined magnetic field and refle...A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation emitted by positrons moving towards the surface of the neutron star along inclined magnetic field and reflected from the surface. Such radiation interferes with transition radiation emitted from the neutron star when positrons hit the surface. Proposed mechanism explains the mystery of the interpulse shift in the Crab pulsar at high frequencies discovered by Moffett and Hankins twenty years ago. We have found also reflected energy flux and spectrum, discussed coherence and disappearance of interpulse shift with increase of frequency.展开更多
The Qianguo Ms5. 8 earthquake swarm of 2013 occurred in Qianguo, Jilin Province, China. There are five earthquakes with Ms ≥5. 0 in the Qianguo earthquake swarm, with magnitudes of Ms 5. 5, Ms 5. 0, Ms 5. 3, Ms 5. 8 ...The Qianguo Ms5. 8 earthquake swarm of 2013 occurred in Qianguo, Jilin Province, China. There are five earthquakes with Ms ≥5. 0 in the Qianguo earthquake swarm, with magnitudes of Ms 5. 5, Ms 5. 0, Ms 5. 3, Ms 5. 8 and Ms 5. 0. In this study, the far-field seismic radiated energy characteristics of the earthquakes are compared based on the source spectrum and the ground motion spectrum of the earthquake swarm. The ground motion spectrum of the five earthquakes at Changchun seismic station (CN2), which is the national standard station, is first investigated with the recorded ground motions, and then the far-field seismic radiated energy is calculated and combined with the relationships of the source spectrum to describe the variable characteristics of the Qianguo earthquake swarm. Research results indicate that the second earthquake (No. 2) with Ms5. 0 is the key event of the earthquake swarm, which occurred on October 31, the same day following the first Ms5. 5 earthquake (No.l). In fact, the magnitude of event No. 2 decreased compared to event No.l, which did not agree with its large far-field seismic radiated energy. It needs to be pointed out that event No. 2 was the turning point event of the Qianguo earthquake swarm, as being a significant transition before the largest Ms5. 8 earthquake.展开更多
Lead iodide single crystal was grown by physical vapor transport method.Two radiation detectors with different configurations were fabricated from the as-grown crystal.The electrical and y-ray response properties at r...Lead iodide single crystal was grown by physical vapor transport method.Two radiation detectors with different configurations were fabricated from the as-grown crystal.The electrical and y-ray response properties at room temperature of the both detectors were investigated.It is found that the dark resistivity of the detectors are respectively 3×10^(10)Ω·cm for bias electric field parallel to crystal c-axis(E//c) and 2×10~8Ω·cm for perpendicular to crystal c-axis(E⊥c).The energy spectrum response measurement shows that both detectors were sensitive to ^(241) Am 59.5 keVγ-rays,and achieved a good energy resolution of 16.8%for the E⊥c-axis configuration detector with a full width at half maximum of 9.996 keV.展开更多
In this paper we discuss the theory of undulator radiation in an electromagnet undulator. We discuss the spectral properties of undulator radiation when electrons are injected off the undulator axis. This paper highli...In this paper we discuss the theory of undulator radiation in an electromagnet undulator. We discuss the spectral properties of undulator radiation when electrons are injected off the undulator axis. This paper highlights the distinctive features of the radiation spectrum from electromagnet undulators, as compared to PPM undulators.展开更多
基金Supported by the Natural Science Foundation of Shanxi Province under Grant No. 2006011012the Shanxi Datong University Doctoral Sustentation Fund
文摘We extend the method that Banerjee and Majhi have used to discuss Hawking radiation. Under the condition that the total energy and electrical charge of spacetime are conserved, we investigate Hawking radiation of the charged black hole by a new Tortoise coordinate transformation. Taking the reaction of the radiation of the particle to the spacetime into consideration, we not only derive the radiation spectrum that satisfies the unitary principle in quantum mechanics but also show that the contribution of ingoing particles is equal to the one of outgoing particles on the similar chemical potential term in radiation spectrum caused by charged particles.
基金supported by the National Natural Science Foundation of China(51875535)the Natural Science Foundation for Young Scientists of Shanxi Province(201701D221017,201901D211242)。
文摘To improve the ability of detecting underwater targets under strong wideband interference environment,an efficient method of line spectrum extraction is proposed,which fully utilizes the feature of the target spectrum that the high intense and stable line spectrum is superimposed on the wide continuous spectrum.This method modifies the traditional beam forming algorithm by calculating and fusing the beam forming results at multi-frequency band and multi-azimuth interval,showing an excellent way to extract the line spectrum when the interference and the target are not in the same azimuth interval simultaneously.Statistical efficiency of the estimated azimuth variance and corresponding power of the line spectrum band depends on the line spectra ratio(LSR)of the line spectrum.The change laws of the output signal to noise ratio(SNR)with the LSR,the input SNR,the integration time and the filtering bandwidth of different algorithms bring the selection principle of the critical LSR.As the basis,the detection gain of wideband energy integration and the narrowband line spectrum algorithm are theoretically analyzed.The simulation detection gain demonstrates a good match with the theoretical model.The application conditions of all methods are verified by the receiver operating characteristic(ROC)curve and experimental data from Qiandao Lake.In fact,combining the two methods for target detection reduces the missed detection rate.The proposed post-processing method in2-dimension with the Kalman filter in the time dimension and the background equalization algorithm in the azimuth dimension makes use of the strong correlation between adjacent frames,could further remove background fluctuation and improve the display effect.
基金supported by National Natural Science Foundation of China(Grant No.11647150)Young Talents Program of Gansu Province of China(2016)Scientific Research Program of the Higher Education Institutions of Gansu Province of China(Grant No.2016A-068)
文摘Based on the theory of plasma continuous radiation, the relationship between the emission intensity of bremsstrahlung and recombination radiation and the plasma electron temperature is obtained. During the development process of a return stroke of ground flash, the intensity of continuous radiation spectrum is separated on the basis of the spectrums with obviously different luminous intensity at two moments. The electron temperature of the lightning discharge channel is obtained through the curve fitting of the continuous spectrum intensity. It is found that electron temperature increases with the increase of wavelength and begins to reduce after the peak. The peak temperature of the two spectra is close to 25 000 K. To be compared with the result of discrete spectrum, the electron temperature is fitted by the O I line and N II line of the spectrum respectively. The comparison shows that the high temperature value is in good agreement with the temperature of the lightning core current channel obtained from the ion line information, and the low temperature at the high band closes to the calculation result of the atomic line, at a low band is lower than the calculation of the atomic line, which reflects the temperature of the luminous channel of the outer corona.
文摘Information is given on thermal radiation from the Sun, considered in practical engineering calculations of heat exchange. It was found that although the surface temperature of the Sun is assumed to be about 5800 K, the solar spectrum data measured by Kondratyev lead to a value of at least 7134 K. Such a higher value can be obtained by interpreting the Planck formula for the black radiation spectrum for the Kondratyev data. In addition, using the Stefan-Boltzmann law, the energetic emissivity of the Sun’s surface was determined to be 0.431. Furthermore, based on Petela’s formulae for exergy of thermal radiation, the exergetic emissivity of the Sun’s surface was also calculated at the level of 0.426.
基金Supported by the National Basic Research Program of China(2009CB522901)Key Project of State Administration of Traditional Chinese Medicine of ChinaShanghai Municipal Science Foundation(11DZ1973300,11ZR1436700, 10QA1406400)
文摘OBJECTIVE:To analyze the distinctive pathological characteristics in the spectrums of spontaneous infrared radiation at the Taiyuan(LU 9) acupoint in patients with asthma.METHODS:A highly sensitive infrared spectrum detecting device was used to detect the spectrums of spontaneous infrared radiation at Taiyuan(LU 9) in 37 asthma patients and 34 healthy volunteers.RESULTS:Asthma patients had significantly lower infrared intensity than that of the healthy volunteers(P>0.01).Asthma patients had significantly lower overall infrared radiation intensity at the left Taiyuan(LU 9) than that of healthy volunteers(P>0.05),but there was no significant difference between healthy volunteers and asthma patients at the right Taiyuan(LU 9)(P>0.05).The infrared radiation intensity of 17 wavelength spots at the left Taiyuan(LU 9) and 4 wavelength spots at the right Taiyuan(LU 9) in asthma patients were significantly lower than those of healthy volunteers(P>0.05).At 2 μm,the infrared radiation intensity of asthma patients was significantly stronger than that of healthy volunteers(P>0.05).At 19 wavelength spots in the healthy volunteers and at 4 wavelength spots in the asthma patients,the left Taiyuan(LU 9) showed a significantly stronger intensity than that of the right Taiyuan(LU 9)(P>0.05).By Pearson's χ2 test,healthy volunteers had more wavelength spots that were significantly different between the left and right Taiyuan(LU 9) than the asthma patients(P>0.01).CONCLUSION:Changes in the infrared spectrum at the Taiyuan(LU 9) acupoint in asthma patients may reflect distinct pathological changes.Certain acupuncture points may be related to specific organs.
基金Supported by the National Natural Science Foundation of China(No.60871053)
文摘With the most advanced Synchronous Radiation Photoelectron Spectrum(SRPS),the emission mechanism of M-type cathodes has been investigated from the perspective of chemical state.Based on the experimental results of SRPS analysis,a new model of the electron emission mechanism for M-type cathode is discussed.The main topics in this paper include the research status of electron emission mechanism of M-type cathodes;the advantages of SRPS technology;the distribution of oxygen chemical state on the cathode surface and the evolvement of oxygen chemical state during activation process;the relation between barium chemical state and osmium(Os)-coating;surplus barium and its formula;the characteristics of Os,and other noble metal coatings;the relation between film characteristics and emission performance of cathodes,the inhibition effects to the emission for Platinum(Pt)-coated cathode,etc.At the end of this paper,electron emission mechanism of M-type cathode is summarized and foreseen.
基金Project supported by the National Natural Science Foundation of China(Grant No10773008)
文摘Extending Parikh and Wilczek's work to the non-stationary black hole, we study the Hawking radiation of the non-stationary Kerr black hole by the Hamilto-Jacobi method. The result shows that the radiation spectrum is not purely thermal and the tunnelling probability is related to the change of Bekenstein Hawking entropy, which gives a correction to the Hawking thermal radiation of the black hole.
文摘A new mechanism of radiation emission in the polar gap of a pulsar is proposed. It is the curvature radiation emitted by positrons moving towards the surface of the neutron star along inclined magnetic field and reflected from the surface. Such radiation interferes with transition radiation emitted from the neutron star when positrons hit the surface. Proposed mechanism explains the mystery of the interpulse shift in the Crab pulsar at high frequencies discovered by Moffett and Hankins twenty years ago. We have found also reflected energy flux and spectrum, discussed coherence and disappearance of interpulse shift with increase of frequency.
基金funded by the National Natural Science Foundation,China(Grant No.41404045,No.41504047)
文摘The Qianguo Ms5. 8 earthquake swarm of 2013 occurred in Qianguo, Jilin Province, China. There are five earthquakes with Ms ≥5. 0 in the Qianguo earthquake swarm, with magnitudes of Ms 5. 5, Ms 5. 0, Ms 5. 3, Ms 5. 8 and Ms 5. 0. In this study, the far-field seismic radiated energy characteristics of the earthquakes are compared based on the source spectrum and the ground motion spectrum of the earthquake swarm. The ground motion spectrum of the five earthquakes at Changchun seismic station (CN2), which is the national standard station, is first investigated with the recorded ground motions, and then the far-field seismic radiated energy is calculated and combined with the relationships of the source spectrum to describe the variable characteristics of the Qianguo earthquake swarm. Research results indicate that the second earthquake (No. 2) with Ms5. 0 is the key event of the earthquake swarm, which occurred on October 31, the same day following the first Ms5. 5 earthquake (No.l). In fact, the magnitude of event No. 2 decreased compared to event No.l, which did not agree with its large far-field seismic radiated energy. It needs to be pointed out that event No. 2 was the turning point event of the Qianguo earthquake swarm, as being a significant transition before the largest Ms5. 8 earthquake.
基金Project supported by the National Natural Science Foundation of China(No.50902012)the Natural Science Foundation of Sichuan Province,China(No.2009JY0087)
文摘Lead iodide single crystal was grown by physical vapor transport method.Two radiation detectors with different configurations were fabricated from the as-grown crystal.The electrical and y-ray response properties at room temperature of the both detectors were investigated.It is found that the dark resistivity of the detectors are respectively 3×10^(10)Ω·cm for bias electric field parallel to crystal c-axis(E//c) and 2×10~8Ω·cm for perpendicular to crystal c-axis(E⊥c).The energy spectrum response measurement shows that both detectors were sensitive to ^(241) Am 59.5 keVγ-rays,and achieved a good energy resolution of 16.8%for the E⊥c-axis configuration detector with a full width at half maximum of 9.996 keV.
文摘In this paper we discuss the theory of undulator radiation in an electromagnet undulator. We discuss the spectral properties of undulator radiation when electrons are injected off the undulator axis. This paper highlights the distinctive features of the radiation spectrum from electromagnet undulators, as compared to PPM undulators.