Dynamically enhanced Autler–Townes splitting by orthogonal XUV fields

Based on numerical solutions of the time-dependent Schr ¨odinger equation, we theoretically investigate the photoelectron spectrum of hydrogen atoms ionized by a pair of ultrashort, intense, and orthogonally polarized laser pulses with a relative time delay in a pump–probe configuration. The pump pulse resonantly excites electrons from the 1s and 2p levels,inducing Rabi oscillations. The resulting dynamically enhanced Autler–Townes(AT) splitting is observed in the photoelectron energy spectrum upon interaction with the second probe pulse. In contrast to the previous parallel-polarization scheme, the proposed orthogonal-polarization configuration enables the resolution of dynamically enhanced AT splitting over a considerably wider range of probe photon energies.

Rydberg electromagnetically induced transparency and Autler–Townes splitting in a weak radio-frequency electric field

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)].

Relationship between electromagnetically-induced transparency and Autler–Townes splitting in a Doppler-broadened system

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.

Effect of pump-1 laser on Autler Townes splitting in photoelectron spectrum of K_2 molecule

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.

The difference in noise property between the Autler-Townes splitting medium and the electromagnetically induced transparent medium

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.

Crossover between electromagnetically induced transparency and Autler–Townes splitting with dispersion

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.

基于里德堡原子天线的短波信号接收技术

短波信号可通过电离层反射实现天波传播,传输时无需通信中继站,具有通信距离远、通信建立迅速、机动灵活、组网容易等优势,因此成为军事通信、应急通信等应用的重要方式。但由于电子学物理机理限制,传统短波天线存在尺寸大、对场地要求高、系统成本高等缺陷。基于里德堡原子天线的短波信号接收技术突破了传统短波天线的物理尺寸限制,具有尺寸小、灵敏度高等诸多优势。本文利用里德堡原子电磁感知系统进行了短波信号接收能力验证,通过对所得的EIT光谱进行转换,进而解调得到短波信号所携带信息,实现了15MHz信号接收,验证了系统短波信号接收能力。文章成果可为里德堡原子电磁感知系统短波通信应用提供技术支撑。

Phase-modulated Autler–Townes splitting in a giant-atom system within waveguide QED

The nonlocal emitter-waveguide coupling,which gives birth to the so called giant atom,represents a new paradigm in the field of quantum optics and waveguide QED.We investigate the single-photon scattering in a one-dimensional waveguide on a two-level or three-level giant atom.Thanks to the natural interference induced by the back and forth photon transmitted/reflected between the atomwaveguide coupling points,the photon transmission can be dynamically controlled by the periodic phase modulation via adjusting the size of the giant atom.For the two-level giant-atom setup,we demonstrate the energy shift which is dependent on the atomic size.For the driven three-level giantatom setup,it is of great interest that,the Autler–Townes splitting is dramatically modulated by the giant atom,in which the width of the transmission valleys(reflection range)is tunable in terms of the atomic size.Our investigation will be beneficial to the photon or phonon control in quantum network based on mesoscopical or even macroscopical quantum nodes involving the giant atom.

Linguistic landscape and its impacts on place-making in mountain destination:A case of Mogan Mountain Town of Huzhou City,China

The place and placeness are believed to be a crucial perspective for comprehending the transformative dynamics of tourist destinations in the context of globalization and the rapid development of the tourism industry.As the material carrier of language,linguistic landscape is an intermediary for people to endow emotions and personalities into the place,becoming an effective path for exploring the place-making in a certain area.Mogan Mountain is a famous national tourist resort,which is located in Mogan Mountain Town,Deqing County,Huzhou City,China.This is a good case area for studying the relationship between linguistic landscape and placemaking in tourist destinations.There are two theories that form the theoretical foundation of the study,namely the place and the geosemiotics.Firstly,the results showed the overall style of the linguistic landscape.Multilingual labelling(52.7%),official signs(55.3%),and standardized Chinese characters predominantly shaped the linguistic landscape,with English and other languages being complementary.Secondly,from the perspective of three dimensions of the geosemiotics framework,such as inscription,language preference,and placement position,we conduct a comprehensive semiotic analysis of the linguistic landscape,which encompasses diverse facets such as fonts,materials,shifts in state,text vectors,and symmetrical arrangements.Finally,we explore the influence of linguistic landscapes on the place-making of Mogan Mountain through the dimensions of location,locale,and sense of place.The information on linguistic landscapes indicates the geographical location.These linguistic landscapes play an important role in constructing the language order,nostalgic atmosphere,exotic atmosphere,and elegant and tasteful lifestyle of the public space in Mogan Mountain.Readers of linguistic landscapes,including tourists and residents,generate and identify with the unique sense of place in Mogan Mountain.These linguistic landscapes construct the destination placeness of Mogan Mountain that combines both foreign and nostalgic styles,and the integration of Chinese and Western cultures.It will help promote the image positioning of tourism destinations and have practical guiding significance for the tourism planning,landscape-making,language management,and other aspects of tourism destinations.

Optimization Study of Active-Passive Heating System Parameters in Village Houses in the Southern Xinjiang Province

Aiming at the problems of large energy consumption and serious pollution of winter heating existing in the rural buildings in Southern Xinjiang,a combined active-passive heating system was proposed,and the simulation software was used to optimize the parameters of the system,according to the parameters obtained from the optimization,a test platform was built and winter heating test was carried out.The simulation results showed that the thickness of the air layer of 75 mm,the total area of the vent holes of 0.24 m^(2),and the thickness of the insulation layer of 120 mm were the optimal construction for the passive part;solar collector area of 28 m^(2),hot water storage tank volume of 1.4 m^(3),mass flow rate of 800 kg/h on the collector side,mass flow rate of 400 kg/h on the heat exchanger side,and output power of auxiliary heat source of 5∼9 kWwere the optimal constructions for active heating system.Test results showed that during the heating period,the system could provide sufficient heat to the room under different heating modes,and the indoor temperature reached over 18°C,which met the heating demand.The economic and environmental benefits of the system were analyzed,and the economic benefits of the systemwere better than coal-fired heating,and the CO_(2) emissionswere reduced by 3,292.25 kg compared with coalfiredheating.The results of the study showed that the combinedactive-passiveheating systemcouldeffectively solve the heating problems existing in rural buildings in Southern Xinjiang,and it also laid the theoretical foundation for the popularization of the combined heating systems.

Development of Rural Tourism Industry under the Background of New Rural Construction : A Case Study of Henghe of Boluo County in Huizhou City

Henghe Town in Boluo County of Huizhou is taken as the research object for analysis.The research and analysis on the tourism industry in Henghe Town of Boluo County are conducted,and the basic situation of rural tourism construction in Henghe Town is sorted out.The forms of tourism industry in Henghe Town and the problems in rural tourism development are identified,and some targeted suggestions and countermeasures are proposed.It hopes to provide ideas and references for the construction of beautiful rural areas in mountainous areas of Guangdong Province,and theoretical reference and practical significance for the development of rural tourism in mountainous areas of Guangdong Province.

Science and Technology Commissioners Supporting High-Quality Development Project for 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.

Design Strategy of Street Space Micro Renewal: A Case Study of Baihuazhou District of Nanchang City

Against the backdrop of incremental planning moving towards stock planning, strengtheningurban public space design to promote high-quality urban development has become a focus of attentionfor domestic scholars. Street is a linear element of urban public space, and it is of great significance forimproving the quality of urban public space by studying the micro renewal design strategy of street space.Based on the interpretation of two urban renewal cases, Wangjing Street in Beijing and Mengzhuiwan inChengdu, taking Baihuazhou area in Nanchang City as an example, this paper analyzes the main problemsin the current situation of street space in Baihuazhou area from three aspects: space use, traffic organization,and waterfront space creation, and explores the micro renewal design strategy of the street space.

Allocation of Public Service Facilities in Villages and Towns from the Perspective of Smart Contraction: A Case Study of Zixi County, Jiangxi Province

The limitation of traditional layout system and the continuous contraction of villages and towns have brought challenges to the layout of public service facilities.It is an imperative task against this background to integrate space resources and allocate public service facilities scientifically and reasonably.This paper took the system and method of rural public service facility allocation from the perspective of smart contraction as the theoretic support,and Zixi County in Jiangxi Province for example,built the four-level life circle of“county-fundamental-basic-routine”based on the influence factors of facility allocation,village and town contraction strength,rural comprehensive assessment results,residents’trip willingness and demands on public service facilities,finally proposed the suggestions for optimizing the allocation of village and town public service facilities.

Landscape Architecture Planning and Design Based on Landscape Ecology Theory:A Case Study of Waterfront Landscape Planning and Design of Dapo Town

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.

A World of Ice and Snow Being also Invaluable Asset:A Case Study of the"Snow Village"

Based on field visit and interview,the current situation of snow village in China is summarized from four aspects:core scenic spots in snow village,skiing industry in snow village,film and television industry in snow village,and ice and snow agritainment.The investigation found that there are still significant problems in homogenization,scenic area infrastructure,and government regulation in snow village.Targeted solutions are proposed from four aspects:tapping internal advantages,strengthening top-level design and infrastructure construction,promoting tourism industry upgrading,and collaborating to innovate the ice and snow tourism supply chain,in order to further promote the economic development of snow village.

Huangyao Ancient Town

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).

Spatial Protection and Development of Traditional Mountain Settlements from the Perspective of Self-organization : A Case Study of Anju Ancient Town in Tongliang District, Chongqing

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.

Visiting Petra

The country of Jordan is rich in history and culture.Out in the desert lies the amazing ancient city of Petra.Most people spend only a few hours in the area.But spending a night in the small town of Wadi Musa is best.Then you can see the sunrise and sunset in Petra.Those are the best times to see the city.To get into Petra,walk through the Siq.A path through the gorge leads you to the Treasury.This marvelous building carved into the rock is Petra's most famous sight.

My Good Friend at Hometown

I have a good friend.His name is Zhang Qiang.He is from Shiyan City,my hometown.He is a middle school student,too.He is very tall and strong.He can play basketball very well.Singing and dancing are his favorite hobbies.I like playing ping-pong.So he often plays ping-pong with me in P.E. class.