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How Does Tropical Cyclone Size Affect the Onset Timing of Secondary Eyewall Formation？

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Journal of Meteorological Research 2018年第1期32卷 124-134页

作者： Liang GUAN xuyang GE Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Nanjing University of Information Science & Technology Nanjing 210044 Shanghai Meteorological Science and Technology Service Center Shanghai 200030

By using idealized numerical simulations, the impact of tropical cyclone size on secondary eyewall formation（SEF） is examined. Both unbalanced boundary layer and balanced processes are examined to reveal the underlying mechanism. The results show that a tropical cyclone（TC） with a larger initial size favors a quicker SEF and a larger outer eyewall. For a TC with a larger initial size, it will lead to a stronger surface entropy flux, and thus more active outer convection. Meanwhile, a greater inertial stability helps the conversion from diabatic heating to kinetic ***, the progressively broadening of the tangential wind field will induce significant boundary layer imbalances. This unbalanced boundary layer process results in a supergradient wind zone that acts as an important mechanism for triggering and maintaining deep convection. In short, different behaviors of balanced and unbalanced processes associated with the initial wind profile lead to different development rates of the secondary eyewall.

关键词： secondary eyewall formation tropical cyclone size surface entropy flux

Multi-User File-Sharing Systems Based on LWE

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China Communications 2020年第7期17卷 166-182页

作者： xuyang Wang Aiqun Hu Hao Fang Southeast University Nanjing 210096China Purple Mountain Laboratories Nanjing 210000China UPSEC Cyber INC.Nanjing 210096 China.

Multi-user file-sharing plays an important role in the cloud *** allows different users to share files via the ***,it usually faces many security issues because the cloud is usually public and *** overcome these issues,we propose multi-user file-sharing systems(MFS)in this *** to the date sources,we propose two frameworks of MFS based on the framework of proxy re-encryption(PRE),unique source(uni-source)MFS and multi-source *** formalize the security models,which contain ciphertext security,secret key security and master secret *** the frameworks,we propose two secure and efficient MFS schemes based on LWE,the uni-source MFS UM and the multi-source MFS *** prove that UM is secret key and ciphertext security,and MM is secret key,master secret and ciphertext security with the hardness assumptions of LWE and ***,we prove they have some useful properties,such as non-interactive and anonymous.

关键词： interactive framework LWE

Comparison of Controlling Parameters for Near-Equatorial Tropical Cyclone Formation between Western North Pacific and North Atlantic

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Journal of Meteorological Research 2021年第4期35卷 623-634页

作者： Changhao LU xuyang GE Melinda PENG Key Laboratory of Meteorological Disaster of Ministry of Education/Joint International Research Laboratory of Climate and Environment Change/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science&TechnologyNanjing 210044China University of Colorado Colorado SpringColorado 80918USA

In this study,the differences in spatial distribution and controlling parameters for the formation of near-equatorial tropical cyclones(NETCs)between the western North Pacific(WNP)and the North Atlantic(NA)are *** exhibit distinctive spatial variabilities in different *** the past few decades,the majority of NETCs took place in WNP while none was observed in *** mechanism behind such a distinguishing spatial distribution difference is analyzed by using statistical *** is noted that the dynamical variables such as low-level relative vorticity and vertical wind shear(VWS)are likely the primary controlling *** with NA,larger low-level vorticity and smaller VWS appear over *** increase of vorticity attributes a lot to the turning of northeast trade *** in WNP tend to occur in the areas with VWS less than 9 m s^(-1),while the VWS in NA generally exceeds 10 m s^(-1).On the other hand,the sea surface temperature in the near-equatorial region of both of the two oceans exceeds 26.5℃and the difference of mid-level moisture is not significant;thus,thermal factors have little contribution to the distinction of NETC activities between WNP and *** oscillation(ISO)and synoptic-scale disturbances in WNP are also shown to be more favorable for NETC *** NETCs were generated in ISO active ***-scale disturbances in WNP obtain more energy from the mean flows through the barotropic energy conversion *** overall unfavorable thermal and dynamic conditions lead to the absence of NETCs in NA.

关键词： near-equatorial tropical cyclone(NETC) cyclogenesis genesis potential index(GPI)

A Review on Applications of Integrated Terahertz Systems

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China Communications 2021年第5期18卷 175-201页

作者： xuyang Lu Suresh Venkatesh Hooman Saeidi University of Michigan–Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai 200240China Department of Electrical and Computer Engineering Princeton UniversityPrincetonNJ 08540USA

A review on Terahertz end-to-end systems with an emphasis on integrated approaches is *** major catalogs of THz integrated systems,including THz communication systems,THz imaging systems,THz radars,and THz spectroscopy systems,are reviewed in this *** performance of integrated systems is compared with non-integrated solutions,followed by a discussion on the trend in future research avenues and applications.

关键词： terahertz integrated circuit imaging communication spectroscopy on-chip antenna CMOS wireless transceivers phased array MIMO

Al-NaOH-Composited Liquid Metal:A Fast-Response Water-Triggered Material with Thermal and Pneumatic Properties

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Engineering 2020年第12期6卷 1454-1462页

作者： Bo Yuan xuyang Sun Jing Liu Department of Biomedical Engineering School of MedicineTsinghua UniversityBeijing 100084China Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Water-triggered materials are receiving increasing attentions due to their diverse capabilities such as easy operation,soft actuation,low cost,environmental friendliness,and many more other ***,most of such materials generally have a long reaction time and require strict preservation conditions,which limit their adaptability in *** this study,a novel water-triggered material based on Al-NaOH-composited eutectic gallium–indium(eGaIn)alloys was proposed and demonstrated,which is rather fast-responsive and *** water is applied,the material thus fabricated would achieve a temperature rise of 40C in just several seconds along with gas production,indicating its big potential to be used as a thermal and pneumatic ***,the new material’s reusability and degradation ability were also *** that,a double-layer-structure smart bandage was designed,whose bulk was filled with Al-NaOH-composited eGaIn while BiInSn served as outer supporting *** to the experiments,a sheet structure with a thickness of 2 mm would support a weight of 1.8 kg after it was subjected to a cooling process,which is much better than the weight-bearing capability of *** addition,a prototype of a water-triggered sphere robot was also fabricated using Al-NaOH-eGaIn,which realized rolling and bouncing behaviors under specific external *** findings indicate the potential value of the present material in developing future wearable devices,soft actuators,and soft robotics.

关键词： Liquid metal Water-triggered materials Self-heating materials Soft actuator

Liquid metal E-tattoo

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Science China(Technological Sciences) 2023年第6期66卷 1551-1575页

作者： GAO Shang CUI ZiLiang WANG XueLin SUN xuyang School of Engineering Medicine Beihang UniversityBeijing 100191China

The past twenty years have witnessed a rapid advancement in medical devices and healthcare *** by the growing demand for personalized,preventive,predictive and participatory medicine,the on-skin portable healthcare system with fascinating merits has attracted great ***,the electronic tattoo(E-tattoo)that can form intimate contact and deform with the skin movement is regarded to play an important role in further healthcare monitoring and disease *** with the combination of fluidity and metallic properties,liquid metals(LMs)have become an emerging class of functional materials and are regarded as the ideal candidate for soft ***,we highlighted the key advantages of LM in E-tattoo,classified the LM based conductive inks,and summarized the important pattern technologies in fabrication of LM *** typical applications of healthcare detection and therapy were also ***,outlooks were provided for future E-tattoo development.

关键词： liquid metal E-tattoo flexible electronic skin printing technologies healthcare applications

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Simulated Sensitivity of the Tropical Cyclone Eyewall Replacement Cycle to the Ambient Temperature Profile

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Advances in Atmospheric Sciences 2017年第9期34卷 1047-1056页

作者： Xulin MA Jie HE xuyang GE Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Key Laboratory of Meteorological DisasterNanjing University of Information Science and Technology

In this study, the impacts of the environmental temperature profile on the tropical cyclone eyewall replacement cycle are examined using idealized numerical simulations. It is found that the environmental thermal condition can greatly affect the formation and structure of a secondary eyewall and the intensity change during the eyewall replacement cycle. Simulation with a warmer thermal profile produces a larger moat and a prolonged eyewall replacement cycle. It is revealed that the enhanced static stability greatly suppresses convection, and thus causes slow secondary eyewall formation. The possible processes influencing the decay of inner eyewall convection are investigated. It is revealed that the demise of the inner eyewall is related to a choking effect associated with outer eyewall convection, the radial distribution of moist entropy fluxes within the moat region, the enhanced static stability in the inner-core region, and the interaction between the inner and outer eyewalls due to the barotropic instability. This study motivates further research into how environmental conditions influence tropical cyclone dynamics and thermodynamics.

关键词： tropical cyclone eyewall replacement cycle ambient temperature profile

Efficient simulation of spatially correlated non-stationary ground motions by wavelet-packet algorithm and spectral representation method

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 799-814页

作者： Ji Kun Cao xuyang Wang Suyang Wen Ruizhi College of Civil and Transportation Engineering Hohai UniversityNanjing 210098China The Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100022China Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China

Although the classical spectral representation method(SRM)has been widely used in the generation of spatially varying ground motions,there are still challenges in efficient simulation of the non-stationary stochastic vector process in *** first problem is the inherent limitation and inflexibility of the deterministic time/frequency modulation *** difficulty is the estimation of evolutionary power spectral density(EPSD)with quite a few *** tackle these problems,the wavelet packet transform(WPT)algorithm is utilized to build a time-varying spectrum of seed recording which describes the energy distribution in the time-frequency *** time-varying spectrum is proven to preserve the time and frequency marginal property as theoretical EPSD will do for the stationary *** the simulation of spatially varying ground motions,the auto-EPSD for all locations is directly estimated using the time-varying spectrum of seed recording rather than matching predefined EPSD *** the constructed spectral matrix is incorporated in SRM to simulate spatially varying non-stationary ground motions using efficient Cholesky decomposition *** addition to a good match with the target coherency model,two numerical examples indicate that the generated time histories retain the physical properties of the prescribed seed recording,including waveform,temporal/spectral non-stationarity,normalized energy buildup,and significant duration.

关键词： non-stationarity time-varying spectrum wavelet packet transform(WPT) spectral representation method(SRM) response spectrum spatially varying recordings

Mechanism study of trans-lamina cribrosa pressure difference correlated to optic neuropathy in individuals with glaucoma

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Science China(Life Sciences) 2020年第1期63卷 148-151页

作者： Qingfeng Liang Leying Wang xuyang Liu Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing Key Laboratory of Ophthalmology and Visual SciencesBeijing 100005China Xiamen Eye Center Xiamen UniversityXiamen 361011China Department of Ophthalmology Shenzhen Ophthalmology HospitalShenzhen 518040China

Glaucoma is the second leading cause of blindness after cataract ***,among irreversible blinding eye diseases,glaucoma is the primary cause(Liang et al.,2011).To date,most studies have indicated that glaucoma is not only an ocular disease,but also an optic nerve *** particular,primary open-angle glaucoma(POAG)is characterized by insidious onset,painless visual impairment,and complicated pathological mechanism,and patients with such condition require long-term ***,the underlying cause of POAG remains unclear,and there are several theories about its exact *** mechanisms have presented underlying optic nerve damage,which include the mechanical theory,vascular theory,and the in・volvement of other factors.

关键词： glaucoma al. cataract