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Optimal Selling Time in Stock Market over a Finite Time Horizon

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Acta Mathematicae Applicatae Sinica 2012年第3期28卷 557-570页

作者： S.C.P.YAM S.P.YUNG w.zhou The Chinese University of Hong Kong China The University of Hong Kong China

In this paper, we examine the best time to sell a stock at a price being as close as possible to its highest price over a finite time horizon [0, T], where the stock price is modelled by a geometric Brownian motion and the ＇closeness＇ is measured by the relative error of the stock price to its highest price over [0, T]. More precisely, we want to optimize the expression：V^＊=sup 0≤τ≤T E[Vτ/MT],where （Vt）t≥0 is a geometric Drownian motion with constant drift α and constant volatility σ 〉 0, Mt = max Vs 0≤a〈t is the running maximum of the stock price, and the supremum is taken over all possible stopping times 0 ≤ τ≤T adapted to the natural filtration （Ft）t≥0 of the stock price. The above problem has been considered by Shiryacv, Xu and zhou （2008） and Du Toit and Peskir （2009）. In this paper we provide an independent proof that when α=1/ 2 σ^2 , a selling strategy is optimal if and only if it sells the stock either at the terminal time T or at the 1 2 moment when the stock price hits its maximum price so far. Besides, when α 〉1/2σ^2 , selling the stock at the terminal time T is the unique optimal selling strategy. Our approach to the problem is purely probabilistic and has been inspired by relating the notion of dominant stopping pr of a stopping time τ to the optimal stopping strategy arisen in the classical ＂Secretary Problem＂.

关键词： optimal Stopping stock selling buy and hold local time

Improving high-temperature mechanical properties of cast CrFeCoNi high-entropy alloy by highly thermostable in-situ precipitated carbides

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Journal of Materials Science & Technology 2021年第13期72卷 29-38页

作者： X.w.Liu N.Gao J.Zheng Y.wu Y.Y.Zhao Q.Chen w.zhou S.Z.Pu w.M.Jiang Z.T.Fan State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan430074China Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621999China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China School of Materials Engineering Purdue UniversityWest LafayetteIN 47907USA Southwest Technology and Engineering Research Institute Chongqing 400039China Center for Electron Microscopy Wuhan UniversityWuhan 430072China

The Cr Fe Co Ni high-entropy alloy(HEA)exhibits excellent mechanical properties at lower temperatures due to its low stacking-fault energy,however,its medium-and high-temperature strengths are still *** consideration of the potential diversified applications,more strengthening approaches except for the previously proposed L12 phase hardening deserve further exploration due to its rapid coarsening tendency at high ***,we achieved significant high-temperature strengthening of the cast Cr Fe Co Ni HEA by in-situ precipitation of highly thermostable *** with 0.5 at.%and 1 at.%niobium and carbon were prepared by simple casting processes,*** cast,solute solution and aging.A highly thermostable microstructure was formed,which comprises very coarse grains accompanied with extensive thermostable carbide precipitates embedded,including submicrometer coherent Nb C particles in grain interiors and intergranular coherent M_(23)C_(6)*** high thermostability of microstructure,which is beneficial for the high-temperature loading,is ascribed to the synergy of lacking growth driving force and Zenner pinning effect by the *** properties tested at 673,873 and1073 K show that the yield strength and ultimate tensile strength are significantly increased by Nb/C doping,along with the elongation escalation at higher *** strengthening is mainly due to the precipitation hardening of carbide particles.

关键词： High-entropy alloy Carbides Precipitation High-temperature property Strengthening

Aeroelasticity Analysis of High-aspect-ratio Composite wing

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Aeroelasticity Analysis of High-aspect-ratio Composite Wing

International Conference on Industrial Technology and Management Science(ITMS 2015)

作者： K.X.Liu w.zhou X.R.wang Xi’an High Technology Institute

The pneumatic elastic model establishing and analysis of the high-aspect-ratio composite wing is an important task for the long-endurance aircraft’s design. The pneumatic elastic analysis theory and fluidstructure interaction（FSI） analysis method are applied in this paper to establish the structured finite element model for the high-aspect-ratio composite wing. Based on the analysis of initialized static model, the software Mp CCI is used to analyze the model with the bidirectional FSI theory, and discuss the pneumatic elasticity characteristics of the wing model in the coupling state. And the relative structure and flow field parameters are supported.

关键词： high aspect ratio composite fluid structure interaction pneumatic elasticity

Coordination-resolved local bond relaxation and electron binding energy shift of PbN atomic clusters

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Coordination-resolved local bond relaxation and electron bin...

第十三届全国物理力学学术会议

作者： M.L.Bo Y.wang Y.L.Huang w.zhou C.Q.Sun Key Laboratory of Low-Dimensional Materials and Application Technologies Ministry of EducationXiangtan University School of Information and Electronic Engineering Hunan University of Science and Technology School of Electrical and Electronic Engineering Nanyang Technological University

Pd is an important constituent in topological insulators with pronounced energy states pertaining to undercoordinated surface and edge atoms but the physical origin of these excessive states remains *** we show that consistency between Density Functional Theory calculations and photoelectron spectroscopy measurements confirmed our theoretical predications on the 5d core level shift of Pb skins and *** is clarified that the shorter and stronger bonds between under-coordinated atoms cause local densification and entrapment of the core electrons,which polarize the otherwise conducting electrons in the skins and edges,which results in the electron binding-energy shift of the skins and *** analysis turns out that the 5d5/2 level shifts from the value of 18.283 e V for an isolated Pb atom by 3.478 e V upon bulk ***,this approach has enabled us to determine the local bond length,bond energy,binding energy density,and atomic cohesive energy at the undercoordinated atomic sites.

关键词： Pb nanoclusters XPS DFT binding energy BOLS

FOLFOX 4 Combined with Herbal Medicine for Advanced Colorectal Cancer:A Systematic Review

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FOLFOX 4 Combined with Herbal Medicine for Advanced Colorect...

第十四届全国中药和天然药物学术研讨会

作者： Menghua Chen Brian H.May Iris w.zhou Charlie C.L.Xue Anthony L Zhang RMIT University VIC Guangdong Provincial Academy of Chinese Medical Sciences & Guangdong Provincial Hospital of Chinese Medicine

＜正＞This systematic review evaluates the clinical evidence for the addition of herbal medicines（HMs）to FOLFOX 4 for advanced colorectal cancer（ACRC）in terms of tumor response rate（tRR）,survival,quality of life and reduction in adverse events（AEs）.Seven electronic databases were searched for randomized controlled trials（RCTs）of FOLFOX4 combined with

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68Ga-FAPI和18F-FDG PET/CT在进展期肺癌评估中的比较

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国际医学放射学杂志 2022年第3期 361-362页

作者： L.wang G.Tang K.Hu X.Liu w.zhou H.Li 任华

摘要镓68(Ga)标记的成纤维细胞活化蛋白抑制剂（FAPI）现已作为一种有前景的肿瘤显像剂。目的比较68GaFAPI PET/CT与氟18(F)标记的氟代氧葡萄糖（FDG）PET/

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A comparative study of proton-conducting fuel cells with BaCe0.8Zr0.1Y0.1O3-δ electrolyte operated on hydrogen,ammonia and hydrazine at intermediate temperatures

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A comparative study of proton-conducting fuel cells with BaC...

第九届全国氢能学术会议

作者： L.Ye,R.Ran,w.zhou,Z.P.Shao,w.Q.Jin,N.P.Xu Nanjing University of Technology,China

＜正＞SOFCs are electrochemical power generation devices characterized by high energy-conversion efficiency and low *** SOFCs are composed of oxygen-ion conducting electrolyte and operated at～1000℃.Reducing the operation temperature of SOFCs to lower than 800℃has many benefits such as versatile cell materials, elegant sealing,reduced electrode sintering,prolonged lifetime,and quicker start-up and *** suggests proton-conducting SOFCs potentially have higher power density than the SOFCs composed of oxygen ion-conducting ***,proton-conducting

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Sb^(3+)and Sm^(3+)co-doped lead-free Cs_(2)NaInCl_(6)double perovskite nanocrystals for single-component cold white emitter

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Journal of Rare Earths 2024年第9期42卷 1646-1651,I0001页

作者： Biao zhou Xiangtong Zhang Ranran Hu Ruixue Hou william w.Yu Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Centre for High-Efficiency Display and Lighting TechnologySchool of Materials and EngineeringCollaborative Innovation Centre of Nano Functional Materials and ApplicationsHenan UniversityKaifeng475000China School of Chemistry and Chemical Engineering Shandong UniversityJinan250100China

Metal halide perovskites exhibit promising prospect in light-emitting diodes,solar cells,photodetectors and ***,the workhorse of metal halide perovskites relies on toxicity lead element,which severely damages human body and *** lead-free perovskites,Cs_(2)NaInCl_(6)double perovskite is one of the most promising candidates because of its great stability and easy synthesis,but suffers inadequate optical ***,we doped Sb^(3+)and Sm^(3+)into Cs_(2)NaInCl_(6)nanocrystals by a hot injection ***_(2)NaInCl_(6):Sb^(3+)exhibits blue emission at 447 ***_(2)NaInCl_(6):Sm^(3+),Sb^(3+)nanocrystals simultaneously generate the blue emission of Sb^(3+)and the multiple emissions of Sm^(3+)at 565,602,650 and 710 *** the increase of Sm^(3+)feed ratio,the emission color of Cs_(2)NaInCl_(6):Sm^(3+),Sb^(3+)gradually moves to cold white region at(0.27,0.28)in CIE chromaticity diagram and correlated color temperature of 11840 *** work shows the potential application of Cs_(2)NaInCl_(6):Sm^(3+),Sb^(3+)nanocrystals as a single-component cold white emitter.

关键词： Lead-free Double perovskites Single component white emitter Doping Rare earths

出血性卒中的老年病人频繁行头颅CT检查的差异性分析

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国际医学放射学杂志 2015年第3期 281-282页

作者： K.Bekelis E.S.Fisher N.Labropoulos w.zhou J.Skinner 牛忠锋 Section of Neurosurgery Dartmouth-Hitchcock Medical Center One Medical Center DriveLebanon NH 03755

目的探讨美国医院内脑出血性卒中病人CT扫描的差异,并分析其与死亡率和会诊医生数量的关系。材料与方法该研究经Dartmouth大学人类保护委员会批准,回顾性

关键词：出血性卒中头颅老年病人 CT