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Birkhoff Normal Form for the Derivative Nonlinear Schrodinger Equation

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Acta Mathematica Sinica,English Series 2022年第1期38卷 249-262页

作者： jian jun LIU School of Mathematics Sichuan UniversityChengdu 610065P.R.China

This paper is concerned with the derivative nonlinear Schr?dinger equation with periodic boundary *** obtain complete Birkhoff normal form of order *** an application,the long time stability for solutions of small amp... 详细信息

关键词： Birkhoff normal form derivative nonlinear Schr?dinger equation long time stability

Evaluation of mobility impact on urban work zones using statistical models

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Journal of Central South University 2017年第6期24卷 1513-1521页

作者： LIU Pei ZHANG jian QU jun-rong LU Jia-jian CHENG Yang tan Hua-chun jiangsu Key Laboratory of Urban ITS Southeast University jiangsu Province Collaborative Innovation Center of Modern Urban Traffic Technologies jiangsu Province Collaborative Innovation Center for Technology and Application of Internet of Things Southeast University Traffic Operations and Safety (TOPS) Laboratory Department of Civil and Environment Engineering University of Wisconsin-Madison Department of Transportation Engineering Beijing Institute of Technology

This work correlated the detailed work zone location and time data from the Wis LCS system with the five-min inductive loop detector data. One-sample percentile value test and two-sample Kolmogorov-Smirnov(K-S) test were applied to compare the speed and flow characteristics between work zone and non-work zone conditions. Furthermore, we analyzed the mobility characteristics of freeway work zones within the urban area of Milwaukee, WI, USA. More than 50% of investigated work zones have experienced speed reduction and 15%-30% is necessary reduced volumes. Speed reduction was more significant within and at the downstream of work zones than at the upstream.

关键词： ITS data mobility impact work zone statistical model

梧州市2010-2014年孕产妇感染调查及高危行为分析

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中国药物滥用防治杂志 2016年第5期22卷 252-254页

作者：钟坚李骏谭琳琳陈懿王冠李勇黄赛伦潘颖梅梁炳健广西梧州市疾病预防控制中心梧州市543000

目的:了解梧州市孕产妇艾滋病、梅毒、丙肝以及高危行为的影响,为评价艾滋病、梅毒、丙肝预防和控制效果提供依据。方法:2010至2014年每年4至7月,对梧州市三县二市的妇幼保健院就诊的6053名孕产妇进行面对面无关联匿名基本情况以及行为... 详细信息

目的:了解梧州市孕产妇艾滋病、梅毒、丙肝以及高危行为的影响,为评价艾滋病、梅毒、丙肝预防和控制效果提供依据。方法:2010至2014年每年4至7月,对梧州市三县二市的妇幼保健院就诊的6053名孕产妇进行面对面无关联匿名基本情况以及行为学调查,并采血样进行艾滋病病毒(HIV)、丙型肝炎病毒(HCV)和梅毒抗体检测。结果:五年共调查了6053名孕产妇,平均年龄(25.05±5.49)岁。0.12%的孕产妇有吸毒史,0.36%的孕产妇丈夫有吸毒史。0.94%的孕产妇存在婚外性行为,1.00%有性病史。2010至2014年孕产妇HIV抗体阳性率分别为0.08%、0.08%、0%、0.16%和0.08%(1/1203)。梅毒抗体阳性率分别为0.50%、0.33%、0.57%、0.16%和0.58%。HCV抗体阳性率分别为0%、0.58%、0.16%、0.16%和0%。结论:孕产妇人群存在性病、艾滋病感染的风险,并有高危行为,应加强对孕产妇人群开展性病艾滋病的宣传教育工作,进一步深化开展各种形式的宣传教育以及行为干预工作。

关键词：孕产妇梅毒 HIV HCV

Effect of aspect ratio on triaxial compression of multi-sphere ellipsoid assemblies simulated using a discrete element method

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Particuology 2017年第3期15卷 49-62页

作者： jian Gong jun Liu State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

Here, we present a numerical investigation of the mechanical behavior of ellipsoids under triaxial com- pression for a range of aspect ratios. Our simulations use a multi-sphere approach in a three-dimensional discrete element method. All assemblies were prepared at their densest condition, and triaxial compres- sion tests were performed up to extremely large strains, until a critical state was reached. The stress-strain relationship and the void ratio-strain behavior were evaluated. We found that the stress-dilatancy rela- tionship of ellipsoids with different aspect ratios could be expressed as a linear equation. In particular, the aspect ratio influenced the position of the critical state lines for these assemblies. Particle-scale char- acteristics at the critical state indicate that particles tend to be flat lying, and the obstruction of particle rotation that occurs with longer particles affects their contact mechanics. Lastly, anisotropic coefficients related to aspect ratio were investigated to probe the microscopic origins of the macroscopic behavior. A detailed analysis of geometrical and mechanical anisotropies revealed the microscopic mechanisms underlying the dependency of peak and residual strengths on aspect ratio.

关键词： EllipsoidsAspect ratio DEM Triaxial compression Particle shape Macro-micro response

High heat loading performance of actively cooled W/Cu FGM-based components

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International Journal of Minerals,Metallurgy and Materials 2011年第4期18卷 467-471页

作者： Zhang-jian Zhou jun tan Dan-dan Qu Hua Li Young-jin yum Hyun-woo Lim School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China Electronic Engineering Institute Hefei 230037 China School of Mechanical ＆ Automotive Engineering University of Ulsan Ulsan 680-749 Korea

A functionally graded material-based actively water-cooled tungsten-copper mockup with a dimension of 30 mm×30 mm×25 mm was designed and fabricated by infiltration-brazing *** thicknesses of the pure W layer and W/Cu graded layer were 2 and 3 mm,*** heat flux tests were performed on the mockup using an e-beam *** is no damage occurring on the joint after heat loading at 5 MW/*** temperature on the pure W surface is less than 500°C after irradiation for 100 s at 5 MW/m2,while the temperature on the brazing seam/copper surface is around 200°C.

关键词： tungsten copper functionally graded materials thermal load

Empirical Likelihood Ratio Confidence Interval for Positively Associated Series

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Acta Mathematicae Applicatae Sinica 2007年第2期23卷 245-254页

作者： jun-jian Zhang College of Applied Sciences Beijing University of Technology Beijing 100022 China College of Mathematics Guangxi Normal University Guilin 541004 China

Empirical likelihood is discussed by using the blockwise technique for strongly stationary, positively associated random variables. Our results show that the statistics is asymptotically chi-square distributed and the... 详细信息

关键词： Empirical likelihood positive association blockwise confidence interval

Reconstructing the landing trajectory of the CE-3 lunar probe by using images from the landing camera

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Research in Astronomy and Astrophysics 2014年第12期14卷 1530-1542页

作者： jian-jun Liu Wei Yan Chun-Lai Li Xu tan Xin Ren Ling-Li Mu Key Laboratory of Lunar and Deep Space Exploration National Astronomical ObservatoriesChinese Academy of Sciences

An accurate determination of the landing trajectory of Chang＇e-3 （CE-3） is significant for verifying orbital control strategy, optimizing orbital planning, accu- rately determining the landing site of CE-3 and analyzing the geological background of the landing site. Due to complexities involved in the landing process, there are some differences between the planned trajectory and the actual trajectory of CE-3. The land- ing camera on CE-3 recorded a sequence of the landing process with a frequency of 10 frames per second. These images recorded by the landing camera and high-resolution images of the lunar surface are utilized to calculate the position of the probe, so as to reconstruct its precise trajectory. This paper proposes using the method of trajectory reconstruction by Single Image Space Resection to make a detailed study of the hov- ering stage at a height of 100 m above the lunar surface. Analysis of the data shows that the closer CE-3 came to the lunar surface, the higher the spatial resolution of im- ages that were acquired became, and the more accurately the horizontal and vertical position of CE-3 could be determined. The horizontal and vertical accuracies were 7.09 m and 4.27 m respectively during the hovering stage at a height of 100.02 m. The reconstructed trajectory can reflect the change in CE-3＇s position during the powered descent process. A slight movement in CE-3 during the hovering stage is also clearly demonstrated. These results will provide a basis for analysis of orbit control strategy, and it will be conducive to adjustment and optimization of orbit control strategy in follow-up missions.

关键词： Moon - methods: data analysis - techniques: image processing

Phonon engineering significantly reducing thermal conductivity of thermoelectric materials: a review

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Rare Metals 2023年第9期42卷 2825-2839页

作者： Chuan-Dong Zhou Bo Liang Wen-Jie Huang Jacques-Guillaume Noudem Xiao-jian tan jun jiang State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao066004China ENSICAEN UNICEFCNRSCRISMATNormandie UniversityNormandie14000CaenFrance Ningbo Institute of Materials Technology and Engineering Chinese Academy of SciencesNingbo315201China

Lattice thermal conductivity, κL, is a fundamental parameter for evaluating the performance of thermoelectric materials. However, the predicted value of κL based on the Debye dispersion model is often overestimated compared with the experimentally determined *** researchers have attempted to modify the theoretical model and have sought more reliable results. In this review,the recent progress in the study of phonon dispersion models is summarized and we propose that the lattice thermal conductivity can be most accurately determined by using the modified sinusoidal phonon dispersion ***, experimental methods that have the potential to reduce a thermoelectric material's κLare reviewed, for example, methods that generate standing waves or anharmonic lattice vibrations. A high concentration of standing waves and anharmonic lattice vibrations can effectively suppress excessive κL. Finally, this review presents the challenges of sinusoidal phonon dispersion when applied to real materials, which are often complicated and therefore time-consuming, especially when dealing with material defects.

关键词： Thermoelectric Lattice thermal conductivity Sinusoidal phonon dispersion model Standing wave Anharmonicity

Synergistic electronic interaction between ruthenium and nickel-iron hydroxide for enhanced oxygen evolution reaction

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Rare Metals 2022年第8期41卷 2606-2615页

作者： Hao Cui Han-Xiao Liao Zhi-Lu Wang jian-Ping Xie Peng-Fei tan De-Wei Chu Pan jun State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China chool of Minerals Processing and Bioengineering Central South UniversityChangsha410083China School of Materials Science and Engineering University of New South WalesSydney2052Australia

The efficiency of electrochemical water splitting is extremely hampered by the sluggish oxygen evolution reaction(OER)occurred at the ***,developing high-performance OER electrocatalysts is crucial for realizing the industrialized application of water ***,a high-efficiency electrocatalyst of ruthenium-decorated nickel-iron hydroxide(10 Ru-NiFe LDH)supported on Ni foam is successfully synthesized for *** NiFe LDH with ruthenium can optimize the electronic density to form high valences of metal sites,which is beneficial to promote its OER ***,the 10 Ru-NiFe LDH only needs a low overpotential of 222 mV to achieve a current density of50 mA,cm^(-2),which exhibits fast OER kinetics with a small Tafel slope of 58 ***^(-1).Moreover,this electrocatalyst shows high stability over 20 h at a high current density of 100 mA·cm^(-2)without obvious *** decent OER performances can be ascribed to the increased active sites and the synergistic electronic interactions among Ni,Fe and *** work provides an effective approach for designing desirable electrocatalysts for OER.

关键词： Ru-decorated NiFe hydroxide Electronic interaction Electrocatalyst Oxygen evolution reaction(OER)