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Measurement of the Absolute Photoionization Cross Section for the 5P_(3/2) State of ^(87)Rb in a Vapor Cell Magneto-optic Trap

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Chinese Physics Letters 2012年第1期29卷 86-89页

作者： HUANG Wei RUAN Ya-ping JIA Feng-Dong zhong Yin-Peng LIU Long-Wei DAI Xing-Can XUE ping XU Xiang-Yuan zhong zhi-ping State Key Laboratory for Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084 College of Physical Sciences Graduate University of the Chinese Academy of SciencesPO Box 4588Beijing 100049 Department of Physics Capital Normal UniversityBeijing 100037

We report the measurement of the absolute photoionization cross section for the 5P_(3/2 )state of ^(87) Rb at wavelength of 473 nm,which results in the photoelectron energies of 33 meV above the ionization threshold,using cold atoms confined in a vapor-loaded magneto-optical *** 87Rb 5P_(3/2 )photoionization cross section at 473nm is determined to be σ_(PI) =10.5 ± 2.2 *** the spatial distribution of the trapped atoms,the average intensity I_(PI) of the ionization laser seen by an atom in the MOT instead of ionizing laser intensity I_(PI) is used in our calculations for the photoionization cross *** excited state fraction is also accurately estimated using the latest experimental result.

关键词： ionization state loaded

The Inversionless Amplification in a Tripod System of SrRb Atoms in a Magneto-optical Trap

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Chinese Physics Letters 2014年第4期31卷 33-36页

作者： SUN Zhen JIA Feng-Dong LV Shuang-Fei RUAN Ya-ping QING Bo XUE ping XU Xiang-yuan DAI Xing-Can zhong zhi-ping School of Physics University of Chinese Academy of Sciences Beijing 100049 State Key Laboratory of Low-dimensional Quantum Physics Department of PhysicsTsinghua University and Collaborative Innovation Center of Quantum M~tter Beijing 100084 Research Center of Laser Fusion China Academy of Engineering Physics Mianyang 621900 Department of Physics Capital Normal University Beijing 100037

The probe transmission spectra around the atomic transition 52S1/2,F = 2 → 52P3/2,F = 2 of 87Rb are measured in a magneto-optical trap by adding a coupling field around the atomic transition 52S1/2, F = 2 → 52 P3/2, F1 = 2. The inversionless amplification is observed in the spectrum over the atomic transition 5 2 S1/2, F = 2 → 52pa/2, Fr = 2. The tripod eleetromagnetically induced transparency is proposed to account for the ampli- fication feature, in which population distributions among these related atomic levels play an important role.

关键词： Trap The Inversionless atomic

Research on thermal insulation materials properties under HTHP conditions for deep oil and gas reservoir rock ITP-Coring

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Petroleum Science 2024年第4期21卷 2625-2637页

作者： zhi-Qiang He He-ping Xie Ling Chen Jian-ping Yang Bo Yu Zi-Jie Wei Ming-zhong Gao State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering College of Water Resource and Hydropower Sichuan University Guangdong Provincial Key Laboratory of Deep Earth Sciences and Geothermal Energy Exploitation and Utilization Institute of Deep Earth Sciences and Green Energy College of Civil and Transportation Engineering Shenzhen University School of Mechanical Engineering Sichuan University College of Polymer Science and Engineering Sichuan University

Deep oil and gas reservoirs are under high-temperature conditions, but traditional coring methods do not consider temperature-preserved measures and ignore the influence of temperature on rock porosity and permeability, resulting in distorted resource assessments. The development of in situ temperaturepreserved coring(ITP-Coring) technology for deep reservoir rock is urgent, and thermal insulation materials are key. Therefore, hollow glass microsphere/epoxy resin thermal insulation materials(HGM/EP materials) were proposed as thermal insulation materials. The materials properties under coupled hightemperature and high-pressure(HTHP) conditions were tested. The results indicated that high pressures led to HGM destruction and that the materials water absorption significantly increased; additionally,increasing temperature accelerated the process. High temperatures directly caused the thermal conductivity of the materials to increase; additionally, the thermal conduction and convection of water caused by high pressures led to an exponential increase in the thermal conductivity. High temperatures weakened the matrix, and high pressures destroyed the HGM, which resulted in a decrease in the tensile mechanical properties of the materials. The materials entered the high elastic state at 150.C, and the mechanical properties were weakened more obviously, while the pressure led to a significant effect when the water absorption was above 10%. Meanwhile, the tensile strength/strain were 13.62 MPa/1.3%and 6.09 MPa/0.86% at 100.C and 100 MPa, respectively, which meet the application requirements of the self-designed coring device. Finally, K46-f40 and K46-f50 HGM/EP materials were proven to be suitable for ITP-Coring under coupled conditions below 100.C and 100 MPa. To further improve the materials properties, the interface layer and EP matrix should be optimized. The results can provide references for the optimization and engineering application of materials and thus technical su

关键词： Deep oil and gas reservoir rock In situ temperature-preserved coring (ITP-Coring) Hollow glass microsphere/epoxy resin thermal insulation materials (HGM/EP materials) High-temperature and high-pressure (HTHP) Physical and mechanical properties

The Probe Transmission Spectra of^(87)Rb in an Operating Magneto-Optical Trap in the Presence of an Ionizing Laser

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Chinese Physics Letters 2013年第4期30卷 69-72页

作者： LIU Long-Wei JIA Feng-Dong RUAN Ya-ping HUANG Wei LV Shuang-Fei XUE ping XU Xiang-Yuan DAI Xing-Can zhong zhi-ping School of Physics University of Chinese Academy of SciencesPO Box 4588Beijing 100049 State Key Laboratory for Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084 Department of Physics Capital Normal UniversityBeijing 100037

The influence of an ionizing laser on the pump-probe spectra of^(87)Rb over the transition 5^(2)S_(1/2),F=2→5^(2)P_(3/2),F'=3 is experimentally studied in an operating magneto-optical *** spectral features,including gain peak,a dispersion-like structure and absorption peak,become weak as the intensity of the ionizing laser ***,the profiles of the absorption peak and gain peak vary as the ionizing laser intensity *** results indicate that there is more than one component in the two features and that each component has different dependences on the number of^(87)Rb atoms.

关键词： pump ionizing Presence

Electrical characteristics of a fractional-order 3×n Fan network

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Communications in Theoretical Physics 2024年第4期76卷 176-187页

作者： zhi-zhong Tan Xin Wang Department of Physics Nantong UniversityNantong 226019China

In this article a new achievement of fractional-order 3×n Fan networks is *** the first step,the RT-I method is used to derive the general formulae of the equivalent impedance of fractional-order 3×n Fan *** the second part,the effects of five system parameters(L,C,n,α and β)on amplitude-frequency and phase-frequency characteristics are *** the same time,the amplitude-frequency and phase-frequency characteristics of the fractional order 3×n Fan network are revealed by Matlab *** work has important theoretical and practical significance for resistor network models in the field of natural science and engineering technology.

关键词： fractional-order circuit amplitude-frequency characteristics phase-frequency characteristics RT-V theory

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Miniaturized power detection module operating in millimeter wave band

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Journal of Electronic Science and Technology 2024年第2期22卷 69-76页

作者： Xiang Zhou zhi-Yong zhong School of Electronic Science and Engineering University of Electronic Science and Technology of ChinaChengdu611731China

The miniaturized broadband detection module can be embedded into the microwave application system such as the front end of the transmitter to detect the power or other parameters in real *** is highly prospective in military and scientific *** this paper,a broadband power detection module operating at 26.5 GHz-40.0 GHz is designed by using low-barrier Schottky diode as the detector and a comparator for threshold *** module can dynamically detect the power range between-10 dBm and 10 dBm with the detection accuracy of 0.1 ***,the temperature compensation circuit is also applied to improve the measurement *** a result,the resulted error low to±1 dB in the temperature range of -55℃ to +85℃ is *** designed module is encapsulated by a Kovar alloy with a small volume of 9 mm×6 mm×3 *** endows the designed module the advantages of small size,easy integration,and low cost,and even it is applicable to high-reliability environments such as satellites.

关键词： Diode Miniaturization Power detection Temperature compensation

New Results in Cooperative Adaptive Optimal Output Regulation

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Journal of Systems Science & Complexity 2024年第1期37卷 253-272页

作者： DONG Yuchen GAO Weinan JIANG zhong-ping State Key Laboratory of Synthetical Automation for Process Industries Northeastern UniversityShenyang 110819China Department of Electrical and Computer Engineering Tandon School of EngineeringNew York UniversityBrooklynNY 11201USA

This paper investigates the cooperative adaptive optimal output regulation problem of continuous-time linear multi-agent *** the multi-agent system dynamics are uncertain,solving regulator equations and the corresponding algebraic Riccati equations is challenging,especially for high-order *** this paper,a novel method is proposed to approximate the solution of regulator equations,i.e.,gradient descent *** is worth noting that this method obtains gradients through online data rather than model information.A data-driven distributed adaptive suboptimal controller is developed by adaptive dynamic programming,so that each follower can achieve asymptotic tracking and disturbance ***,the effectiveness of the proposed control method is validated by simulations.

关键词： Adaptive dynamic programming cooperative output regulation gradient descent method multi-agent systems.

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Dark Localized Waves in Shallow Waters:Analysis within an Extended Boussinesq System

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Chinese Physics Letters 2024年第4期41卷 32-37页

作者： Zhengping Yang Wei-ping zhong Milivoj Belic Department of Medical Science Shunde PolytechnicShunde 528300China Department of Electronic Engineering Shunde PolytechnicShunde 528300China Division of Arts and Sciences Texas A&M University at Qatar23874 DohaQatar

We study dark localized waves within a nonlinear system based on the Boussinesq approximation,describing the dynamics of shallow water *** symbolic calculus,we apply the Hirota bilinear method to transform an extended Boussinesq system into a bilinear form,and then use the multiple rogue wave method to obtain its dark rational *** the first-and second-order dark solutions,we examine the conditions under which these localized solutions exist and their spatiotemporal *** the selection of various parameters and by utilizing different visualization techniques(intensity distributions and contour plots),we explore the dynamical properties of dark solutions found:in particular,the first-and second-order dark rogue *** also explore the methods of their *** findings presented here not only deepen the understanding of physical phenomena described by the(1+1)-dimensional Boussinesq equation,but also expand avenues for further *** method can be extended to other nonlinear systems,to conceivably obtain higher-order dark rogue waves.

关键词： Boussinesq bilinear nonlinear

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Prediction of contact resistance of electrical contact wear using different machine learning algorithms

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Friction 2024年第6期12卷 1250-1271页

作者： Zhen-bing CAI Chun-lin LI Lei YOU Xu-dong CHEN Li-ping HE zhong-qing CAO zhi-nan ZHANG Tribology Research Institute Southwest Jiaotong UniversityChengdu 610031China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

H62 brass material is one of the important materials in the process of electrical energy transmission and signal transmission,and has excellent performance in all *** the wear behavior of electrical contact pairs is particularly complex when they are in service,we evaluated the effects of load,sliding velocity,displacement amplitude,current intensity,and surface roughness on the changes in contact *** learning(ML)algorithms were used to predict the electrical contact performance of different factors after wear to determine the correlation between different factors and contact *** forest(RF),support vector regression(SVR)and BP neural network(BPNN)algorithms were used to establish RF,SVR and BPNN models,respectively,and the experimental data were trained and *** was proved that BP neural network model could better predict the stable mean resistance of H62 brass alloy after *** analysis shows that the load and current have great influence on the predicted electrical contact *** wear behavior of electrical contacts is influenced by factors such as load,sliding speed,displacement amplitude,current intensity,and surface roughness during *** learning algorithms can predict the electrical contact performance after wear caused by these *** results indicate that an increase in load,current,and surface roughness leads to a decrease in stable mean resistance,while an increase in displacement amplitude and frequency results in an increase in stable mean resistance,leading to a decline in electrical contact *** reduce testing time and costs and quickly obtain the electrical contact performance of H62 brass alloy after wear caused by different factors,three algorithms(random forest(RF),support vector regression(SVR),and BP neural network(BPNN))were used to train and test experimental results,resulting in a machine learning model suitable for predicting the stable mean

关键词： electrical contact wear contact resistance machine learning(ML) neural network