This paper discusses the important role of science and technology commissioners in the high-quality development of hundreds of counties,thousands of towns,and myriads of villages in the context of rural revitalization...This paper discusses the important role of science and technology commissioners in the high-quality development of hundreds of counties,thousands of towns,and myriads of villages in the context of rural revitalization,including building bridges,accelerating the transformation of achievements,promoting the value-added of the whole agricultural industry chain,and promoting the rapid development of rural industrial economy.It also discusses the working achievements of science and technology commissioners,in order to promote further development of rural revitalization in Guangdong Province.展开更多
HUANGYAO Ancient Town is located in the northeast of Zhaoping County in Hezhou City,south China’s Guangxi Zhuang Autonomous Region.Around 60 kilometers from downtown,the ancient town covers an area of over 3.2 square...HUANGYAO Ancient Town is located in the northeast of Zhaoping County in Hezhou City,south China’s Guangxi Zhuang Autonomous Region.Around 60 kilometers from downtown,the ancient town covers an area of over 3.2 square kilometers.It traces its origin to the early days of the Song Dynasty(960-1279).The town expanded during the Ming Dynasty(1368-1644)and flourished during the Qing Dynasty(1644-1911).展开更多
With the rapid development of urbanization,landscape architecture has become an indispensable component of daily life.In order to achieve better landscape effects and protect the ecological environment,landscape ecolo...With the rapid development of urbanization,landscape architecture has become an indispensable component of daily life.In order to achieve better landscape effects and protect the ecological environment,landscape ecology theory can be integrated into landscape planning to carry out disciplinary crossing and integration research between landscape ecology and landscape architecture.In this study,based on the basic theories of landscape ecology,the waterfront landscape of Dapo Town was designed,with the aim to achieve ecological balance in planning,showcase biodiversity,and create a harmonious landscape ecological environment which can benefit both nature and people.This design combined artificial and natural elements while improving the natural environment,which promoted a harmonious relationship between humans and nature,thus enriching the spatial organization of the city,and playing a role in regulating the urban environment and climate.展开更多
Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant charact...Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.展开更多
We utilize an electromagnetically induced transparency(EIT) of a three-level cascade system involving Rydberg state in a room-temperature cell, formed with a cesium 6 S_(1/2)–6 P_(3/2)–66 S_(1/2) scheme, to investig...We utilize an electromagnetically induced transparency(EIT) of a three-level cascade system involving Rydberg state in a room-temperature cell, formed with a cesium 6 S_(1/2)–6 P_(3/2)–66 S_(1/2) scheme, to investigate the Autler–Townes(AT)splitting resulting from a 15.21-GHz radio-frequency(RF) field that couples the |66 S_(1/2) → |65 P_(1/2) Rydberg transition.The radio-frequency electric field induced AT splitting, γAT, is defined as the peak-to-peak distance of an EIT-AT spectrum.The dependence of AT splitting γAT on the probe and coupling Rabi frequency, ?_p and ?_c, is investigated. It is found that the EIT-AT splitting strongly depends on the EIT linewidth that is related to the probe and coupling Rabi frequency in a weak RF-field regime. Using a narrow linewidth EIT spectrum would decrease the uncertainty of the RF field measurements.This work provides new experimental evidence for the theoretical framework in [J. Appl. Phys. 121, 233106(2017)].展开更多
We theoretically investigate the Autler–Townes(AT) splitting in the photoelectron spectrum of four-level ladder K2 molecule driven by a pump 1-pump 2-probe pulse via employing the time-dependent wave packet approac...We theoretically investigate the Autler–Townes(AT) splitting in the photoelectron spectrum of four-level ladder K2 molecule driven by a pump 1-pump 2-probe pulse via employing the time-dependent wave packet approach. The effects of the pump-1 laser intensity and wavelength on AT splitting are studied for the first time. The magnitude of AT splitting increases with increasing the pump-1 laser intensity. The triple splitting with asymmetric profile occurs due to the nonresonant excitation. The triple structure is transformed into a double structure(near-resonant region), and then becomes a peak(far-off resonant region) progressively as the pump-1 laser is detuned from the resonance wavelength, which can be explained in terms of the asymmetric excitation/population of dressed states. The splitting between adjacent peaks and the splitting between the two sideband peaks in the triplet do not change with the pump-1 pulse wavelength. The three peaks shift toward lower energy with the same shift 1/4^*△1 as the pump-1 wavelength changes in near-resonant region.The asymptotic behaviors of AT splitting with the pump-1 laser intensity are interesting in the threshold points of the near-resonant region and the far-off resonant region.展开更多
We investigate Autler-Townes splitting in the photoelectron spectra of K2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach. It is found that the magnitude of Aulter-Townes spl...We investigate Autler-Townes splitting in the photoelectron spectra of K2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach. It is found that the magnitude of Aulter-Townes splitting varies with the wavelength of the intense laser pulse. In particular, the phenomenon of Aulter-Townes splitting vanishes for the far-off resonance of the pump pulse. Also, the split peaks of Autler Townes in the case of resonant pump pulse give us an approach to directly obtaining the transition dipole moment of a molecule.展开更多
The quantum noise of squeezed probe light passing through an atomic system with different electromagnetically induced transparency and AutlewTownes splitting effects is investigated theoretically. It is found that the...The quantum noise of squeezed probe light passing through an atomic system with different electromagnetically induced transparency and AutlewTownes splitting effects is investigated theoretically. It is found that the optimal squeezing preservation of the outgoing probe beam occurs in the strong-coupling-field regime rather than in the weak- coupling-field regime. In the weak-coupling-field regime, which was recently recognized as the electromagnetically induced transparency regime (Abi-Salloum T Y 2010 Phys. Rev. A 81 053836), the output amplitude noise is affected mainly by the atomic noise originating from the random decay process of atoms. While in the strong-coupling-field regime, defined as the Autler-Townes splitting regime, the output amplitude noise is affected mainly by the phase-to- amplitude conversion noise. This is useful in improving the quality of the experiment for efficient quantum memory, and hence has an application in quantum information processing.展开更多
Autler-Townes splitting in absorption spectra of the excited states 6^ 2P3/2 - 8^2S1/2 Of cold cesium atoms confined in a magneto-optical trap has been observed. Experimental data of the Autler-Townes splitting fit we...Autler-Townes splitting in absorption spectra of the excited states 6^ 2P3/2 - 8^2S1/2 Of cold cesium atoms confined in a magneto-optical trap has been observed. Experimental data of the Autler-Townes splitting fit well to the dressedatom theory, by which the fact of the cold atoms dressed by cooling/trapping laser beams is revealed. The results of the theoretical fitting with experiment not only told us the effective Rabi frequency cold atoms experienced, but also could be used for measuring the probability amplitudes of the dressed states.展开更多
An Autler-Townes(AT) spectroscopy based on phase conjugate six-wave mixing(SWM) is proposed to detect AT doublet of high-lying state in a Doppler-broadened cascade four-level system.It is found that the SWM spectr...An Autler-Townes(AT) spectroscopy based on phase conjugate six-wave mixing(SWM) is proposed to detect AT doublet of high-lying state in a Doppler-broadened cascade four-level system.It is found that the SWM spectrum is dependent strongly on the ratios between the magnitudes of the wave vectors.We discuss how the Doppler broadening affects the SWM spectrum from a time-domain viewpoint and find that,due the atomic motion,the atomic polarizations acquire different phases for atoms with different velocities as time evolves.The Doppler free SWM spectrum can be obtained only when the atomic polarization can be rephasing again at certain time after the interactions of all the incident fields.展开更多
用光学 光学双共振激光光谱研究了 7Li2 A1Σ+ u 态的Autler Townes (A T)分裂 .一个强的耦合场 (泵浦激光 )激发 7Li2 A1Σ+ u v′ ,J′←X1Σ+ g v″,J″跃迁 ,诱发A1Σ+ u v′ ,J′能级和X1Σ+ g v″ ,J″能级的A T分裂 .另一个探测...用光学 光学双共振激光光谱研究了 7Li2 A1Σ+ u 态的Autler Townes (A T)分裂 .一个强的耦合场 (泵浦激光 )激发 7Li2 A1Σ+ u v′ ,J′←X1Σ+ g v″,J″跃迁 ,诱发A1Σ+ u v′ ,J′能级和X1Σ+ g v″ ,J″能级的A T分裂 .另一个探测激光从A1Σ+ u v′ ,J′能级进一步激发到 4 1Σ+ g 态 .扫描探测激光 ,监测 4 1Σ+ g 态碰撞诱导紫色荧光 ,从而探测A1Σ+ u v′,J′能级的A T分裂 .当耦合场频率偏离共振时 ,激发光谱线出现双重分裂 .在该实验条件下 ,分裂大小和泵浦激光频率偏离共振频率的失谐量成正比 .研究了A T分裂的两条线的相对强度与泵浦、探测光的强度及缓冲气体压力的关系 .展开更多
We study the relationship between electromagnetically-induced transparency(EIT) and Autler–Townes(AT) splitting in a cascade three-level Doppler-broadened system. By comparing the absorption spectrum with the flu...We study the relationship between electromagnetically-induced transparency(EIT) and Autler–Townes(AT) splitting in a cascade three-level Doppler-broadened system. By comparing the absorption spectrum with the fluorescence excitation spectrum, it is found that for a Doppler-broadened system, EIT resonance cannot be explained as the result of quantum interference, unlike the case of a homogeneously broadened system. Instead, the macroscopic polarization interference plays an important role in determining the spectra of EIT and AT splitting, which can be explained within the same framework when being detected by the absorption spectra.展开更多
Based on Akaike's information criterion(AIC) for a coherently driven ensemble of cold rubidium atoms, we study the crossover between electromagnetically induced transparency(EIT) and Autler–Townes(AT) splittin...Based on Akaike's information criterion(AIC) for a coherently driven ensemble of cold rubidium atoms, we study the crossover between electromagnetically induced transparency(EIT) and Autler–Townes(AT) splitting from the dispersion as well as the absorption viewpoint. We find that the dispersion signal is more sensitive than the absorption signal, showing more pronounced features in the Akaike per-point weights spectrum, which provides a cleaner way of discerning EIT from AT splitting.展开更多
With a coupling laser locked to caesium 6S1/2 Fg=4-6P3/2 Fe=5 cycling transition and a co-propagating probe laser scanned across 6S1/2 Fg=4-6Pa/2 Fe=3, 4 and 5 transitions, a novel scheme for sub-Doppler spectra in Do...With a coupling laser locked to caesium 6S1/2 Fg=4-6P3/2 Fe=5 cycling transition and a co-propagating probe laser scanned across 6S1/2 Fg=4-6Pa/2 Fe=3, 4 and 5 transitions, a novel scheme for sub-Doppler spectra in Dopplerbroadened V-type three-level system is demonstrated by detecting the transmission of the coupling laser through a caesium vapour cell. The Autler-Townes doublet in the sub-Doppler spectra of the coupling laser is clearly observed. The effects of coupling laser intensity on the splitting and linewidth of the Autler-Townes doublet are experimentally investigated and the results agree well with theoretical predictions. Taking the multiple hyperfine levels of caesium atom into account, a brief analysis is presented.展开更多
文摘This paper discusses the important role of science and technology commissioners in the high-quality development of hundreds of counties,thousands of towns,and myriads of villages in the context of rural revitalization,including building bridges,accelerating the transformation of achievements,promoting the value-added of the whole agricultural industry chain,and promoting the rapid development of rural industrial economy.It also discusses the working achievements of science and technology commissioners,in order to promote further development of rural revitalization in Guangdong Province.
文摘HUANGYAO Ancient Town is located in the northeast of Zhaoping County in Hezhou City,south China’s Guangxi Zhuang Autonomous Region.Around 60 kilometers from downtown,the ancient town covers an area of over 3.2 square kilometers.It traces its origin to the early days of the Song Dynasty(960-1279).The town expanded during the Ming Dynasty(1368-1644)and flourished during the Qing Dynasty(1644-1911).
文摘With the rapid development of urbanization,landscape architecture has become an indispensable component of daily life.In order to achieve better landscape effects and protect the ecological environment,landscape ecology theory can be integrated into landscape planning to carry out disciplinary crossing and integration research between landscape ecology and landscape architecture.In this study,based on the basic theories of landscape ecology,the waterfront landscape of Dapo Town was designed,with the aim to achieve ecological balance in planning,showcase biodiversity,and create a harmonious landscape ecological environment which can benefit both nature and people.This design combined artificial and natural elements while improving the natural environment,which promoted a harmonious relationship between humans and nature,thus enriching the spatial organization of the city,and playing a role in regulating the urban environment and climate.
基金the General Project of National Natural Science Foundation of China(51778078)General Project of Natural Science Foundation of Chongqing City(cstc2021jcyj-msxmX1055).
文摘Through literature research, field research and urban design analysis methods, based on the self-organization theory, the evolution characteristics of the settlement space of Anju Ancient Town with significant characteristics of traditional mountain settlements were analyzed, and then its internal and external influencing factors were summarized. Finally, appropriate protection and development strategies were proposed, such as reasonably planning functional zones, breaking through the single structure, and creating a good living cultural environment. The innovation of this study is that it integrates the self-organization theory into the cognition of traditional mountain settlement space, and discusses the connection between the mountain settlement space and the traditional regional context under the modern development concept, so as to seek the benign protection and reasonable development of traditional mountain settlement space.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFA0304203)the National Natural Science Foundation of China(Grant Nos.61475090,61675123,61775124,and 11804202)+1 种基金the State Key Program of National Natural Science of China(Grant Nos.11434007 and61835007)the Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(Grant No.IRT13076)
文摘We utilize an electromagnetically induced transparency(EIT) of a three-level cascade system involving Rydberg state in a room-temperature cell, formed with a cesium 6 S_(1/2)–6 P_(3/2)–66 S_(1/2) scheme, to investigate the Autler–Townes(AT)splitting resulting from a 15.21-GHz radio-frequency(RF) field that couples the |66 S_(1/2) → |65 P_(1/2) Rydberg transition.The radio-frequency electric field induced AT splitting, γAT, is defined as the peak-to-peak distance of an EIT-AT spectrum.The dependence of AT splitting γAT on the probe and coupling Rabi frequency, ?_p and ?_c, is investigated. It is found that the EIT-AT splitting strongly depends on the EIT linewidth that is related to the probe and coupling Rabi frequency in a weak RF-field regime. Using a narrow linewidth EIT spectrum would decrease the uncertainty of the RF field measurements.This work provides new experimental evidence for the theoretical framework in [J. Appl. Phys. 121, 233106(2017)].
基金The code used in our calculation is provided by Pro- fessor Ke-li Han from Dalian Institute of Chemical Physics, Chinese Academy of Science, and we appreci- ate his help and kind advice. This work was supported by the National Natural Science Foundation of China (No.11447020), the Natural Science Foundation of Hu- nan province (No.2015JJ3104), and the Scientific Re- search Foundation for the Returned Overseas Chinese Scholars, State Education Ministry.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.41104094 and 11174119)the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20114324120002)+1 种基金the Research Foundation of Education Bureau of Hunan Province,China(Grant No.12C0370)the Scientific Research Foundation for the Returned Overseas Chinese Scholars
文摘We theoretically investigate the Autler–Townes(AT) splitting in the photoelectron spectrum of four-level ladder K2 molecule driven by a pump 1-pump 2-probe pulse via employing the time-dependent wave packet approach. The effects of the pump-1 laser intensity and wavelength on AT splitting are studied for the first time. The magnitude of AT splitting increases with increasing the pump-1 laser intensity. The triple splitting with asymmetric profile occurs due to the nonresonant excitation. The triple structure is transformed into a double structure(near-resonant region), and then becomes a peak(far-off resonant region) progressively as the pump-1 laser is detuned from the resonance wavelength, which can be explained in terms of the asymmetric excitation/population of dressed states. The splitting between adjacent peaks and the splitting between the two sideband peaks in the triplet do not change with the pump-1 pulse wavelength. The three peaks shift toward lower energy with the same shift 1/4^*△1 as the pump-1 wavelength changes in near-resonant region.The asymptotic behaviors of AT splitting with the pump-1 laser intensity are interesting in the threshold points of the near-resonant region and the far-off resonant region.
基金supported by the National Natural Science Foundation of China (Grant Nos.91021009 and 10874102)the Research Fund for the Doctoral Program of Higher Education,China (Grant No.200804220004)
文摘We investigate Autler-Townes splitting in the photoelectron spectra of K2 molecule driven by pump-probe pulses via employing the time-dependent wave packet approach. It is found that the magnitude of Aulter-Townes splitting varies with the wavelength of the intense laser pulse. In particular, the phenomenon of Aulter-Townes splitting vanishes for the far-off resonance of the pump pulse. Also, the split peaks of Autler Townes in the case of resonant pump pulse give us an approach to directly obtaining the transition dipole moment of a molecule.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 10974126 and 60821004)the National Basic Research Program of China (Grant No. 2010CB923102)
文摘The quantum noise of squeezed probe light passing through an atomic system with different electromagnetically induced transparency and AutlewTownes splitting effects is investigated theoretically. It is found that the optimal squeezing preservation of the outgoing probe beam occurs in the strong-coupling-field regime rather than in the weak- coupling-field regime. In the weak-coupling-field regime, which was recently recognized as the electromagnetically induced transparency regime (Abi-Salloum T Y 2010 Phys. Rev. A 81 053836), the output amplitude noise is affected mainly by the atomic noise originating from the random decay process of atoms. While in the strong-coupling-field regime, defined as the Autler-Townes splitting regime, the output amplitude noise is affected mainly by the phase-to- amplitude conversion noise. This is useful in improving the quality of the experiment for efficient quantum memory, and hence has an application in quantum information processing.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60978017,61078051,10974125,and 60821004)the NCET Project from the Education Ministry of China (Grant No. NCET-07-0524)the Specialized Research Fund for the Doctoral Program of China (Grant No. 20070108003)
文摘Autler-Townes splitting in absorption spectra of the excited states 6^ 2P3/2 - 8^2S1/2 Of cold cesium atoms confined in a magneto-optical trap has been observed. Experimental data of the Autler-Townes splitting fit well to the dressedatom theory, by which the fact of the cold atoms dressed by cooling/trapping laser beams is revealed. The results of the theoretical fitting with experiment not only told us the effective Rabi frequency cold atoms experienced, but also could be used for measuring the probability amplitudes of the dressed states.
基金Project supported by the National Basic Research Program of China(Grant No.2013CB922002)the National Natural Science Foundation of China(Grant Nos.11274376 and 61308011)the National High Technology Research and Development Program of China(Grant No.2011AA120102)
文摘An Autler-Townes(AT) spectroscopy based on phase conjugate six-wave mixing(SWM) is proposed to detect AT doublet of high-lying state in a Doppler-broadened cascade four-level system.It is found that the SWM spectrum is dependent strongly on the ratios between the magnitudes of the wave vectors.We discuss how the Doppler broadening affects the SWM spectrum from a time-domain viewpoint and find that,due the atomic motion,the atomic polarizations acquire different phases for atoms with different velocities as time evolves.The Doppler free SWM spectrum can be obtained only when the atomic polarization can be rephasing again at certain time after the interactions of all the incident fields.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11404330,11274376,61308011,and 11474347)the NSAF,China(Grant No.U1330117)+1 种基金the National Basic Research Program of China(Grant Nos.2013CB922002 and 2010CB922904)the China Postdoctoral Science Foundation(Grant No.119103S239)
文摘We study the relationship between electromagnetically-induced transparency(EIT) and Autler–Townes(AT) splitting in a cascade three-level Doppler-broadened system. By comparing the absorption spectrum with the fluorescence excitation spectrum, it is found that for a Doppler-broadened system, EIT resonance cannot be explained as the result of quantum interference, unlike the case of a homogeneously broadened system. Instead, the macroscopic polarization interference plays an important role in determining the spectra of EIT and AT splitting, which can be explained within the same framework when being detected by the absorption spectra.
基金Project supported by the National Basic Research Program of China(Grant Nos.2013CB922002 and 2010CB922904)the National Natural Science Foundation of China(Grant Nos.11274376,61308011,and 11474347)
文摘Based on Akaike's information criterion(AIC) for a coherently driven ensemble of cold rubidium atoms, we study the crossover between electromagnetically induced transparency(EIT) and Autler–Townes(AT) splitting from the dispersion as well as the absorption viewpoint. We find that the dispersion signal is more sensitive than the absorption signal, showing more pronounced features in the Akaike per-point weights spectrum, which provides a cleaner way of discerning EIT from AT splitting.
基金Project supported by the National Natural Science Foundation of China (Grant Nos 60578018, 10434080 and 10374062), by the Key Scientific Program of Education Ministry of China (Grant No 204019), and by the Research Funds for Youth Academic Leaders of Shanxi Province, China.
文摘With a coupling laser locked to caesium 6S1/2 Fg=4-6P3/2 Fe=5 cycling transition and a co-propagating probe laser scanned across 6S1/2 Fg=4-6Pa/2 Fe=3, 4 and 5 transitions, a novel scheme for sub-Doppler spectra in Dopplerbroadened V-type three-level system is demonstrated by detecting the transmission of the coupling laser through a caesium vapour cell. The Autler-Townes doublet in the sub-Doppler spectra of the coupling laser is clearly observed. The effects of coupling laser intensity on the splitting and linewidth of the Autler-Townes doublet are experimentally investigated and the results agree well with theoretical predictions. Taking the multiple hyperfine levels of caesium atom into account, a brief analysis is presented.