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Magic Wavelengths for a Lattice Trapped Rubidium Four-Level Active Optical Clock

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Chinese Physics Letters 2012年第9期29卷 24-27页

作者： ZANG Xiao-Run ZHANG Tong-Gang chen jing-biao Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System&NetworkSchool of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871

After being pumped from the 5s_(1/2) ground state to the 6p_(1/2) state,the population inversion between 6s_(1/2) and 5p_(1/2,3/2) can be established for a rubidium four-level active optical *** calculate the ac Stark shift due to lattice trapping laser which dominates the frequency shift of clock transition in a lattice trapped rubidium four-level active optical *** magic wavelengths are found,which can form desired optical lattice trapping *** choosing a proper intensity and linewidth of the trapping laser,the fractional frequency uncertainty of clock transition due to the ac Stark shift of the trapping laser,is estimated to be below 10^(−18).

关键词： pumped trapping Magic

Dynamical Behavior of an Atomic Beam Interacting with a Fock State Light Field

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Chinese Physics Letters 2010年第1期27卷 100-103页

作者：李犇陈景标 Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication System & Network School of Electronics Engineering & Computer Science Peking University Beijing 100871

The collapse and revival of evolution with photon number of population inversion in the case of an atomic beam with velocity distribution interacting with a single-mode and Fock-state light field is investigated by full quantum theory. Compared to the previously reported coherent state case [Li B and chen J B Chin. Phys. Lett. 26（2009）123203], which was induced by evolution with coupling strength of population inversion, in the case under consideration there exists Poisson distribution of photon numbers and atomic velocity distribution in the beam. Moreover, we prove that above, the collapse and revival have an analogy with conventional collapse and revival [Eberly J H et al. Phys. Rev. Lett. 44（1980）1323] in both the mathematical expression and physical significance.

关键词： Chinese climate network complex systems small world community

Alternating Current Zeeman and Stark Interference Effect in Ramsey Separated Oscillating Fields

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Chinese Physics Letters 2001年第2期18卷 202-204页

作者： chen jing-biao WANG Feng-Zhi YANG Dong-Hai WANG Yi-Qiu Department of Electronics and Key Laboratory for Quantum Information and Measurements of Education MinistryPeking UniversityBeijing 100871

Analytic expressions have been derived of the alternating current(ac)Zeeman and ac Stark effect in an atomic beam magnetic resonance method using Ramsey separated oscillating *** interesting feature which will affect the normal Ramsey pattern is that an interference fringe is superimposed on the dispersion lineshapes of the normal ac Zeeman or ac Stark *** point out that this new character of ac Zeeman(ac Stark)effect generally exists in all kinds of Ramsey method,for example,in the optical Ramsey atomic interferometer and atomic beam frequency *** important implication is that,particularly in an atomic beam frequency standard using Ramsey method,this effect has an influence on the evaluation of the second-order Doppler frequency shift.

关键词： effect Ramsey Zeeman

A New Pumping-Probing Scheme for the Optically Pumped Cesium Beam Frequency Standard

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Chinese Physics Letters 2001年第1期18卷 16-17页

作者： chen jing-biao ZHU cheng-Jin WANGFeng-Zhi YANG Dong-Hai WANG Yi-Qiu Department of Electronics Peking UniversityBeijing 100871

A new pumping-probing scheme for the optically pumped cesium beam frequency standard has been experimentally tested in our *** stability of the optically pumped cesium beam frequency standard was measured by comparing its 10 MHz output with an HP5071A commercial cesium atomic *** result shows that the frequency stability for the 1 s and 30000s sample times are 1.2×10^(-11) and 3.7×10^(-13),*** was proved that the new pumping scheme works well.

关键词： pumping pumped Optically

A Potassium Atom Four-Level Active Optical Clock Scheme

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Chinese Physics Letters 2013年第4期30卷 34-37页

作者： ZHANG Sheng-Nan WANG Yan-Fei ZHANG Tong-Gang ZHUANG Wei chen jing-biao Institute of Quantum Electronics and State Key Laboratory of Advanced Optical Communication and System Network School of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871

We present an active optical clock scheme with a four-level quantum potassium *** calculate the population probabilities of each state using the density *** the steady state,ρ33 andρ55 are equal to 8.3%and 3.5%,respectively,and the population inversion between the 5S1/2 and 4P3/2 states is built up in the thermal potassium cell with a 404.7 nm pumping *** to the mechanism of the active optical clock,under the action of the 404.7 nm pumping laser,the scheme can output a 1252.2 nm quantum-limited-linewidth laser,which can be directly used as an active optical frequency standard.

关键词： pumping potassium quantum

Cerebral furin deficiency causes hydrocephalus in mice

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Genes & Diseases 2024年第3期11卷 438-451页

作者： Shiqi Xie Xiaoyong Xie jing Tang biao Luo Jian chen Qixin Wen Jianrong Zhou Guojun chen Nursing College Chongqing Medical UniversityChongqing 400016China Department of Neurology The First Affiliated Hospital of Chongqing Medical UniversityChongqing Key Laboratory of Major Neurological and Mental DisordersChongqing Key Laboratory of NeurologyChongqing 400016China

Furin is a pro-protein convertase that moves between the trans-Golgi network and cell surface in the secretory *** have previously reported that cerebral overexpres-sion of furin promotes cognitive functions in ***,by generating the brain-specific furin conditional knockout(ckO)mice,we investigated the role of furin in brain *** found that furin deficiency caused early death and growth *** resonance im-aging showed severe *** the brain of furin cko mice,impaired ciliogenesis and the derangement of microtubule structures appeared along with the down-regulated expres-sion of RAB28,a ciliary vesicle *** line with the widespread neuronal loss,ependymal cell layers were *** proteomics analysis revealed that cell adhesion molecules including astrocyte-enriched ITGB8 and BCAR1 were altered in furin cKO mice;and astrocyte overgrowth was accompanied by the reduced expression of sox9,indicating a disrupted differ-entiation into ependymal ***,whereas alteration of RAB28 expression correlated with the role of vesicle trafficking in ciliogenesis,dysfunctional astrocytes might be involved in ependymal damage contributing to hydrocephalus in furin ckO *** structural and mo-lecular alterations provided a clue for further studying the potential mechanisms of furin.

关键词： Astrocyte Ciliogenesis Conditionalknockout Ependymal Furin Hydrocephalus Proteomics

Exploring a new path of green and efficient utilization of sinter return fine to produce composite pellets

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Journal of Iron and Steel Research International 2024年第7期31卷 1610-1622页

作者： Yan-biao chen Wen-guo Liu Hao Guo jing-song Wang Qing-guo Xue Hai-bin Zuo State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China MCC Capital Engineering and Research Incorporation Limited Beijing 100176China

Efficient utilization of sinter return fine is an important measure to reduce cost,increase efficiency,save energy and reduce emission.A new path of green and efficient utilization of return fine was proposed to produce composite *** metallurgical properties of composite pellets under the condition of hydrogen-rich blast furnace were *** experimental results indicate that the coated concentrate was consolidated for the composite pellets through normal Fe_(2)O_(3) *** the surface of core return fine,the liquid phase formed due to its low-melting point,assimilated the adjacent concentrate,and then consolidated with the temperature *** with regular pellets,the com-pressive strength and reduction swelling index of composite pellets were decreased,but the reducibility index and softening-melting properties were *** addition,the reduction degradation index of composite pellets was sig-nificantly higher than that of ***,adding composite pellets was conducive to indirect reduction in blast furnace,reducing fuel ratio and improving production *** to the effect of the roasting system on the metallurgical properties,the roasting temperature and time were determined as 1250℃and 30 min,*** composite pellets can be produced under the traditional pelletizing process.

关键词： Sinter Return fine Composite pellet Roasting system Metallurgical property Hydrogen-rich blast furnace

Effect of the yaw angle on turbulent flow structures around the submarine model

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Journal of Hydrodynamics 2024年第3期36卷 421-434页

作者： Yi-jing Hu Yi Qu Qin Wu biao Huang School of Mechanical Engineering Beijing Institute of TechnologyBeijing100081China Beijing Institute of Electronic System Engineering Beijing100854China

The objective of this paper is to investigate the turbulent flow structures around the submarine model and evaluate the effect of the yaw angle on the turbulent flow *** large eddy simulation based on the boundary data immersion method is used to *** computational domain consists of 1.2×10^(8)uniformly distributed Cartesian orthogonal grid nodes to capture the basic flow characteristics around the *** pressure coefficient,friction coefficient and wake velocity distribution are in good agreement with the experimental *** different types of vortex structures were mainly captured around the model,including horseshoe vortex,sail tip vortex and crossflow separation *** the increase of the yaw angle,the asymmetry of the horseshoe vortex and the tip vortex gradually increases,and the vortex strength of the vortex leg on the windward of the horseshoe vortex and the vortex strength of the tip vortex also increase *** the crossflow separation vortex,the flow separation zone gradually expands and migrates downstream with the increase of the yaw angle.

关键词： Vortex structure submarine model boundary data immersion method yaw angle

Cs 455nm Nonlinear Spectroscopy with Ultra-narrow Linewidth

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Chinese Physics Letters 2013年第6期30卷 50-52页

作者： WANG Dong-Ying WANG Yan-Fei TAO Zhi-Ming ZHANG Sheng-Nan HONG Ye-Long ZHUANG Wei chen jing-biao State Key Laboratory of Advanced Optical Communication System and Network Institute of Quantum ElectronicsSchool of Electronics Engineering&Computer SciencePeking UniversityBeijing 100871

Nonlinear spectroscopy has become a useful tool in laser cooling,frequency stabilization and so *** use the 455.5 nm light beam output of an external cavity diode laser to perform the saturation spectroscopy signal and polarization spectroscopy signal on the 6S_(1/2)→7P3/2 transition in *** measured linewidth of the F4→4,5 transition is as narrow as 1.40 MHz and that of the F3→2,3 transition is 1.67 *** of them are very close to the natural linewidth of about 1.2 *** result is the narrowest measured linewidth of Cs 455 nm saturation spectroscopy signal to our knowledge.

关键词： polarization narrow signal