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Extending the trapping lifetime of single atom in a microscopic far-off-resonance optical dipole trap

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Frontiers of physics 2011年第3期6卷 262-270页

作者： jun he Bao-dong YANG Yong-jie CheNG Tian-cai ZHANG jun-min WANG State Key Laboratory of Quantum Optics and Quantum Optics Devices and Institute of Opto Electronics Shanxi University Taiyuan 030006 China

In our experiment, a single cesium atom prepared in a large-magnetic-gradient magneto optical trap （MOT） can be efficiently transferred into a 1064-nm far-off-resonance microscopic optical dipole trap （FORT）. The efficient transfer of the single atom between the two traps is used to determine the trapping lifetime and the effective temperature of the single atom in FORT. The typical trapping lifetime has been improved from ~ 6.9 s to ~ 130 s by decreasing the background pressure from 1 × 10^-10 Torr to ~ 2 × 10^-11 Torr and applying one-shot 10-ms laser cooling phase. We also theoretically investigate the dependence of trapping lifetimes of a single atom in a FORT on trap parameters based on the FORT beam＇s intensity noise induced heating. Numerical simulations show that the heating depends on the FORT beam＇s waist size and the trap depth. The trapping time can be predicted based on effective temperature measurement of a single atom in the FORT and the intensity noise spectra of the FORT beam. These experimental results are found to be in agreement with the predictions of the heating model.

关键词： magneto optical trap (MOT) far-off-resonance optical dipole trap (FORT) singleatom trapping lifetime release-and-recapture method (R&R) effective temperature

Characterizations of Lie Triple Derivations on the Algebra of Operators in Hilbert C*-Modules

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Journal of Mathematical Research with Applications 2024年第3期44卷 387-396页

作者： Guangyu AN jun SheNG jun he Department of Mathematics Shaanxi University of Science and Technology Department of Mathematics Anhui Polytechnic University

Let A be a commutative unital C*-algebra with the unit element e and M be a full Hilbert *** by EndA（M） the algebra of all bounded A-linear mappings on M and by M′the set of all bounded A-linear mappings from M into *** this paper,we prove that if there exists x0in M and f0in M′such that f0（x0）=e,then every A-linear Lie triple derivation on EndA（M） is standard.

关键词： Lie triple derivation standard derivation Hilbert C*-module

Some Inequalities for Tree Martingales

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Acta Mathematicae Applicatae Sinica 2005年第4期21卷 671-682页

作者： Tong-jun he You-liang Hou College of Mathematics and Computer Science Fuzhou University Fuzhou 35002 China School of Mathematics and Statistics Wuhan University Wuhan 430072 China

In this paper we study tree martingales and proved that if 1≤α,β〈∞,1≤p〈∞ then for every predictable tree martingale f=（ft,t∞T）and E[σ^（P）（f）]〈∞,E[S^（P）（f）]〈∞,it holds that ‖（St^（p）（f）,t∈T）‖M^α∞≤Cαβ‖f‖p^αβ,‖（σt^（p）（f）,t∈T）‖M^α,β‖f‖P^αβ,where Cαβ depends only on α and β.

关键词： Tree martingale quadratic variation conditional quadratic variation

Synthesis and antitumor activity of N^1-acetylamino-(5-alkyl/aryl-1,3,4-thiadiazole-2-yl)-5-fluorouracil derivatives

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Chinese Chemical Letters 2008年第11期19卷 1281-1284页

作者： Kai Bo Zheng jun he Jie Zhang College of Chemistry Sichuan University Chengdu 610064 China Department of Nephrology West China Hospital Sichuan University Chengdu 610041 China

A new series of N^1-acetylamino-（5-alkyl/aryl- 1,3,4-thiadiazole-2-yl）-5-fluorouracil derivatives were designed and synthesized. These compounds have not been reported in literature, and their structure chemical were confirmed by IR, ^1H NMR and MS （HRMS）. The results of antitumor inhibitory activity test showed that some compounds possess more potent antitumor inhibitory activity than 5-fluorouracil.

关键词： 5-Fluorouracil derivatives 1,3,4-Thiadiazole Synthesis Antitumor

Pore structure evolution during the coke graphitization process in a blast furnace

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International Journal of Minerals,Metallurgy and Materials 2020年第9期27卷 1226-1233页

作者： Hao-bin Zhu Wen-long Zhan Zhi-jun he Ying-chang Yu Qing-hai Pang jun-hong Zhang School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051China Ansteel Engineering Technology Corporation Limited Anshan 114021China

Pore structure is an important factor influencing coke strength,while the property of coke is essential to maintaining gas and liquid permeability in a blast ***,an in-depth understanding of the pore structure evolution during the graphitization process can reveal the coke size degradation behavior during its descent in a blast *** graphitization was simulated at different heating temperatures from 1100 to 1600℃ at intervals of 100℃.The quantitative evaluation of the coke pore structure with different graphitization degree was determined by vacuum drainage method and nitrogen adsorption *** show that the adsorption and desorption curves of graphitized coke have intersection points,and the two curves did not coincide,instead forming a“hysteresis loop.”Based on the hysteresis loop analysis,the porous structure of the graphitized coke mostly appeared in the shape of a“hair follicle.”Furthermore,with an increase in heating temperature,the apparent porosity,specific surface area,total pore volume,and amount of micropores showed good correlation and can divided into three stages:1100-1200,1200-1400,and 1400-1600℃.When the temperature was less than 1400℃,ash migration from the inner part mainly led to changes in the coke pore *** the temperature was greater than 1400℃,the pore structure evolution was mainly affected by the coke graphitization *** results of scanning electron microscopy,energy dispersive spectrometry,and ash content analyses also confirmed that the migration of the internal ash to the surface of the matrix during the graphitization process up to 1400℃ contributed to these changes.

关键词： coke blast furnace graphitization pore structure ash migration

Mechanical Behavior of a Partially Encased Composite Girder with Corrugated Steel Web： Interaction of Shear and Bending

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Engineering 2017年第6期3卷 806-816页

作者： jun he Sihao Wang Yuqing Liu Zhan Lyu Chuanxi Li School of Civil Engineering Changsha University of Science and Technology Changsha 410114 China Department of Bridge Engineering Tonal University Shanghai 200092 China Department of Civil and Environmental Engineering Imperial College London London SW7 2AZ UK

The synergistic use of partially encased concrete and composite girders with corrugated steel webs （CGCSWs） has been proposed to avoid the buckling of corrugated steel webs and compression steel flanges under large combined shear force and bending moment in the hogging area. First, model tests were carried out on two specimens with different shear spans to investigate the mechanical behavior, including the load-carrying capacity, failure modes, flexural and shear stress distribution, and development of concrete cracking. Experimental results show that the interaction of shear force and bending moment causes the failure of specimens. The bending-to-shear ratio does not affect the shear stiffness of a composite girder in the elastic stage when concrete cracking does not exist, but significantly influ- ences the shear stiffness after concrete cracking. In addition, composite sections in the elastic stage sat- isfy the assumption of the plane section under combined shear force and bending moment. However, after concrete cracking in the tension field, the normal stresses of a corrugated web in the tension area become small due to the ＂accordion effect,＂ with almost zero stress at the flat panels but recognizable stress at the inclined panels. Second, three-dimensional finite-element （FE） models considering material and geometric nonlinearity were built and validated by experiments, and parametric analyses were conducted on composite girders with different lengths and heights to determine their load-carrying capacity when subjected to combined loads. Finally, an interaction formula with respect to shear and flexural strength is offered on the basis of experimental and numerical results in order to evaluate the load- carrying capacity of such composite structures, thereby providing a reference for the design of partially encased composite girders with corrugated steel webs （PECGCSWs） under combined flexural and shear loads.

关键词： Encased concrete Composite girder Corrugated steel web Interaction of shear and bending

Spatiotemporal Variations of Meteorological Droughts in China During 1961–2014: An Investigation Based on Multi-Threshold Identification

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International Journal of Disaster Risk Science 2016年第1期7卷 63-76页

作者： jun he Xiaohua Yang Zhe Li Xuejun Zhang Qiuhong Tang Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences School of Environment Beijing Normal University University of Chinese Academy of Sciences

As a major agricultural country, China suffers from severe meteorological drought almost every *** studies have applied a single threshold to identify the onset of drought events, which may cause problems to adequately characterize long-term patterns of *** study analyzes meteorological droughts in China based on a set of daily gridded(0.5° 9 0.5°) precipitation data from 1961 to 2014. By using a multi-threshold run theory approach to evaluate the monthly percentage of precipitation anomalies index(Pa), a drought events sequence was identified at each grid cell. The spatiotemporal variations of drought in China were further investigated based on statistics of the frequency, duration,severity, and intensity of all drought events. Analysis of the results show that China has five distinct meteorological drought-prone regions: the Huang-Huai-Hai Plain, Northeast China, Southwest China, South China coastal region,and Northwest China. Seasonal analysis further indicates that there are evident spatial variations in the seasonal contribution to regional drought. But overall, most contribution to annual drought events in China come from the winter. Decadal variation analysis suggests that most of China's water resource regions have undergone an increase in drought frequency, especially in the Liaohe, Haihe, and Yellow River basins, although drought duration and severity clearly have decreased after the 1960 s.

关键词： China Meteorological drought Multi-threshold run theory method Spatiotemporal variations

Optical investigations reveal the effects of 2-aminoethyldiphenyl borate on STIM1 puncta formation

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Journal of Innovative Optical health Sciences 2018年第2期11卷 51-64页

作者： Tao Yu Shangbin Chen Jingying Pan Conglin Su jun he Division of Histology and Embryology School of Basic Medicine Tongji Medical College Huazhong University of Science and Technology WuhanP.R.China Wuhan Children's Hospital(Wuhan Maternal and Child healthcare Hospital)Tongji Medical College Huazhong University of Science and TechnologyWuhanP.R.China Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for Optoelectronics-Huazhong University of Science and Technology WuhanP.R.China

2-A minoethyldiphenyl borate(2-APB)is the most commonly used pharmacological agent in the study of calcium release-activated channels(CRACa);however,its inhibitory mechanism to CRACs remains *** address this issue,we systematically employed confocal imaging,dual-wavelength excitation photometry and FRET to examine the effects of 2-APB on the dynamic activities and function of STIM1 and Orail,two key components of *** results support that there are two signaling pathways(Orail-independent and Orail-dependent)for the formation of STM1 puncta.2 APB could dose dependently block Orail-independent but not Oril-dependent STIM1 puncta formation,despite its obvious inhibition effect on store-opented Ca^(2+)entry(SOCE).In addition,we found that although 2-APB could not visibly alter near plasma membrane CAD-eYFP localization,it could completely block CAD-YFP-induced constitutive Ca^(2+)entry and promnote the interaction between Orail and CAD by FRET ***,we proposed that inhibitory action of 2-APB on SOCE might attribute to its direct inhbitory effects on Orail channel itself,but not the interference on puncta formation between STIM1 and Orail.

关键词： SOCE CRAC 2-arminoethyldiphenyl bornate STIM1 Orail confocal imaging FRET

Recent Progress in the Fabrication, Properties, and Devices of heterostructures Based on 2D Materials

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Nano-Micro Letters 2019年第1期11卷 217-240页

作者： Yanping Liu Siyu Zhang jun he Zhiming M.Wang Zongwen Liu School of Physics and Electronics Hunan Key Laboratory for Super-Microstructure and Ultrafast ProcessCentral South University State Key Laboratory of Electronic Thin Films and Integrated Devices University of Electronic Science and Technology of China School of Chemical and Biomolecular Engineering The University of Sydney

With a large number of researches being conducted on two?dimen?sional(2D) materials, their unique properties in optics, electrics, mechanics, and magnetics have attracted increasing attention. Accordingly, the idea of combining distinct functional 2D materials into heterostructures naturally emerged that pro?vides unprecedented platforms for exploring new physics that are not accessible in a single 2D material or 3D heterostructures. Along with the rapid development of controllable, scalable, and programmed synthesis techniques of high?quality 2D heterostructures, various heterostructure devices with extraordinary performance have been designed and fabricated, including tunneling transistors, photodetectors, and spintronic devices. In this review, we present a summary of the latest progresses in fabrications, properties, and applications of di erent types of 2D heterostruc?tures, followed by the discussions on present challenges and perspectives of further investigations.

关键词： Two-dimensional(2D) materials 2D heterostructures Charge and magnetotransport Electronic and optoelectronic devices