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Track Prediction of Typhoon Neoguri 2008

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Communications in Theoretical Physics 2009年第2期51卷 363-366页

作者： JIA man Department of Physics Shanghai Jiao Tong University Shanghai 200240 China

In this paper, the prediction of the track for No.1 tropical cyclone, Neoguri, is concretely provided by using a special solution to （2-1）-dimensional Euler Equation.

关键词： tropical cyclone Euler equation the induced flow

Can cold dark matter paradigm explain the central-surface-densities relation?

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Research in Astronomy and Astrophysics 2017年第7期17卷 109-114页

作者： man-Ho Chan Department of Science and Environmental Studies The Education University of Hong Kong

Recently, a very strong correlation between the central surface density of stars and dynamical mass in 135 disk galaxies has been obtained. It has been shown that this central-surface-densities relation agrees very well with Modified Newtonian Dynamics（MOND）. In this article, we show that if we assume the baryons have an isothermal distribution and dark matter exists, then it is possible to derive by means of the Jeans equation an analytic central-surface-densities relation connecting dark matter and baryons that agrees with the observed relation. We find that the observed central-surface-densities relation can also be accommodated in the context of dark matter provided the latter is described by an isothermal profile. Therefore, the observed relation is consistent with not only MOND.

关键词： (cosmology:) dark matter

Forms and Aesthetics of Bridges

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Engineering 2018年第2期4卷 103-112页

作者： man-Chung Tang Chinese Academy of Engineering Beijing 100088 China US National Academy of Engineering Washington DC 20001 USA T.Y. Lin International Group San Francisco CA 94104 USA

The objective of a bridge design is to produce a safe bridge that is elegant and satisfies all functionality requirements, at a cost that is acceptable to the owner. A successful bridge design must be natural, simple, original, and harmonious with its surroundings. Aesthetics is not an additional consideration in the design of a bridge, but is rather an integral part of bridge design. Both the structural configuration and the aesthetics of a bridge must be considered together during the conceptual design stage. To achieve such a task, the bridge design engineer must have a good understanding of structural theory and bridge aesthetics.

关键词： Form Aesthetics Bridge Concept Design Environment

Novel travelling wave structures:few-cyclepulse solitons and soliton molecules

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Communications in Theoretical Physics 2021年第2期73卷 23-29页

作者： Zitong Chen man Jia School of Physical Science and Technology Ningbo UniversityNingbo 315211China

We discuss a fifth order KdV(FOKdV)equation via a novel travelling wave method by introducing a background *** show that the background term plays an essential role in finding new abundant travelling wave structures,such as the soliton induced by negative background,the periodic travelling wave excited by the positive background,the few-cycle-pulse(FCP)solitons with and without background,the soliton molecules excited by the *** FCP solitons are first obuained for the FOKdV equation.

关键词： New travelling method a fifth order KdV equation solitons induced by background few-cycle-pulse solitons soliton molecules

Relationship between high dietary fat intake and Parkinson’s disease risk: a meta-analysis

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Neural Regeneration Research 2019年第12期14卷 2156-2163页

作者： Yan Qu Xi Chen man-man Xu Qiang Sun Department of Physiology School of Basic Medicine Qingdao University Qingdao Shandong Province China Intensive Care Unit The Affiliated Hospital of Qingdao University Qingdao Shandong Province China

OBJECTIVE: To assess whether dietary fat intake influences Parkinson’s disease risk. DATA SOURCES: We systematically surveyed the Embase and PubMed databases, reviewing manuscripts published prior to October 2018. The following terms were used:(“Paralysis agitans” OR “Parkinson disease” OR “Parkinson” OR “Parkinson’s” OR “Parkinson’s disease”) AND (“fat” OR “dietary fat” OR “dietary fat intake”). DATA SELECTION: Included studies were those with both dietary fat intake and Parkinson’s disease risk as exposure factors. The Newcastle-Ottawa Scale was adapted to investigate the quality of included studies. Stata V12.0 software was used for statistical analysis. OUTCOME MEASURES: The primary outcomes included the relationship between high total energy intake, high total fat intake, and Parkinson’s disease risk. The secondary outcomes included the relationship between different kinds of fatty acids and Parkinson’s disease risk. RESULTS: Nine articles met the inclusion criteria and were incorporated into this meta-analysis. Four studies scored 7 and the other five studies scored 9 on the Newcastle-Ottawa Scale, meaning that all studies were of high quality. Meta-analysis results showed that high total energy intake was associated with an increased risk of Parkinson’s disease (P = 0.000, odds ratio (OR)= 1.49, 95% confidence interval (CI): 1.26–1.75);in contrast, high total fat intake was not associated with Parkinson’s disease risk (P = 0.123, OR = 1.07, 95% CI: 0.91–1.25). Subgroup analysis revealed that polyunsaturated fatty acid intake (P = 0.010, OR = 1.03, 95% CI: 0.88–1.20) reduced the risk of Parkinson’s disease, while arachidonic acid (P = 0.026, OR = 1.15, 95% CI: 0.97–1.37) and cholesterol (P = 0.002, OR = 1.09, 95% CI: 0.92–1.29) both increased the risk of Parkinson’s disease. Subgroup analysis also demonstrated that, although the results were not significant, consumption of n-3 polyunsaturated fatty acids (P = 0.071, OR = 0.88, 95% CI: 0.73–1.05),α-linolenic ac

关键词： nerve regeneration dietary fat Parkinson's disease risk meta-analysis total energy intake polyunsaturated fatty acids arachidonic acid cholesterol α-linolenic acid linoleic acid n-3/n-6 polyunsaturated fatty acid intake ratio monounsaturated fatty acids neural regeneration

Robust fault detection of piecewise affine ARX systems

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Journal of Control and Decision 2020年第3期7卷 276-285页

作者： Young-man Kim School of Engineering Liberty University1971 University Blvd.LynchburgVAUSA

In this paper,l1 regularisation-based robust fault detection technique for PWARX(PieceWise affine Auto Regressive eXogenous)systems is *** problem is formulated in convex optimisation form using l1 regularisation hence,global solution can be *** regularisation constant plays a key role for finding the number of *** MSE(mean square error)value between actual system and its model under no fault is used as a threshold for tracking dynamics change and detecting *** simplicity of turning only one parameter(regularisation constant)outstands this approach from *** proposed algorithm also shows the capability of separating the dynamics change from additive fault under *** illustration concludes this proposal by demonstrating its effectiveness.

关键词： Piecewise affine ARX fault detection regularisation convex optimisation sparsity

Influence of the Acoustic Liner in Large Eddy Simulation of Longitudinal Thermoacoustic Instability in a Model Annular Combustor

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Journal of Thermal Science 2024年第2期33卷 710-724页

作者： MENG Sheng ZHANG man GAO Yi AECC Commercial Aircraft Engine Co. Ltd.Shanghai200241China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai200240China

Although extensive efforts have been made to dampen the thermoacoustic instability,successfully controlling the pressure oscillations in modern gas turbines or aeroengines remains *** influence of the acoustic liner on the longitudinal thermoacoustic mode in a model annular combustor is investigated by Large Eddy Simulation(LES) in this *** result of the self-excited longitudinal thermoacoustic instability without the liner agrees well with the frequency and acoustic analysis of the pressure mode based on experimental *** different bias flow velocities of the liner located downstream of the combustor are then *** results reveal that the existence of the liner influences not only the acoustic field but also the flow *** the bias velocity is large,it leads to intense turbulence-induced fluctuations,and the pressure oscillation is modulated *** shows that the weak coupling between flow and pressure oscillations plays a significant role in the onset of the intermittency of a thermoacoustic *** on the dynamic analysis of the thermoacoustic system with the acoustic liner,this intermittency is caused by the influence of the flow field on the flame-acoustic ***,a low-order modeling method based on Van der Pol(VdP) oscillator with additive stochastic forcing is conducted to reproduce the evolving dynamics of the thermoacoustic *** the numerical cases demonstrated in this work are relatively simpler than those in a practical combustion system,the results are helpful for us to understand the effect of the acoustic liner and show the attractive potential to apply this device to suppress thermoacoustic instability.

关键词： thermoacoustic instability acoustic liner Large Eddy Simulation low-order modeling

Does the gamma-ray signal from the central Milky Way indicate Sommerfeld enhancement of dark matter annihilation?

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Research in Astronomy and Astrophysics 2016年第10期16卷 116-120页

作者： man-Ho Chan Department of Science and Environmental Studies The Education University of Hong Kong

Recently, some studies showed that the GeV gamma-ray excess signal from the central Milky Way can be explained by the annihilation of -40 GeV dark matter through the bb channel. Based on the morphology of the gamma-ray flux, the best-fit inner slope of the dark matter density profile is γ = 1.26. However, recent analyses of the Milky Way dark matter profile favor γ = 0.6 - 0.8. In this article, we show that the GeV gamma-ray excess can also be explained by the Sommerfeld-enhanced dark matter annihilation through the bb channel with γ = 0.85 - 1.05. We constrain the parameters of the Sommerfeld-enhanced annihilation by using data from Fermi-LAT. We also show that the predicted gamma-ray fluxes emitted from dwarf galaxies generally satisfy recent upper limits on gamma-ray fluxes detected by Fermi-LAT.

关键词： (cosmology): dark matter

Adaptive control of nonlinear systems with severe uncertainties in the input powers

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Science China(Information Sciences) 2021年第1期64卷 227-238页

作者： Linzhen YU Yungang LIU Yongchao man School of Control Science and Engineering Shandong University

In this study, we discuss global adaptive stabilization for a class of uncertain nonlinear *** input powers of the system are unknown, and the upper bound and the nonzero lower bound are not known in advance. This suggests that the system suffers from severe uncertainties with respect to the input powers when compared with the related literature, which would considerably challenge the control design. The switching-based strategy can compensate for severe system uncertainties, especially new types of uncertainties, including those associated with the input powers. Herein, a switching adaptive controller is successfully designed to ensure that the resulting closed-loop system states are globally bounded and ultimately converge to the origin(the equilibrium point). The proposed controller is extended to the systems with unknown control directions by redefining the involved switching sequences. A simulation example demonstrates the effectiveness of the proposed switching adaptive controller.

关键词： nonlinear systems severe uncertainties global stabilization unknown input powers switching adaptive control