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Kerr effect and Kerr constant enhancement in vertically aligned deformed helix ferroelectric liquid crystals

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Chinese Physics B 2016年第9期25卷 9-12页

作者： Liangyu Shi Abhishek Kumar Srivastava Vladimir G Chigrinov Hoi-sing.Kwok State Key Laboratory on Advanced Displays and Optoelectronics Technologies Hong Kong University of Science and Technology

In this article,we review recently achieved Kerr effect progress in novel liquid crystal（LC） material：vertically aligned deformed helix ferroelectric liquid crystal（VADHFLC）.With an increasing.applied electric field,the induced inplane birefringence of LCs shows quadratic *** theoretical calculations and experimental details are *** an enhanced Kerr constant to 130 nm/V2,this VADHFLC cell can achieve a 2π modulation by a small efficient electric field with a fast response around 100 μs and thus can be employed in both display and photonics devices.

关键词： Kerr effect deformed helix ferroelectric liquid crystal phase modulation of light

Novel metastable Bi:Co and Bi:Fe alloys nanodots@carbon as anodes for high rate K-ion batteries

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Nano Research 2022年第8期15卷 7220-7226页

作者： Zhongqiu Tong Tianxing Kang Yan Wu Fan Zhang Yongbing Tang Chun-sing.Lee Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Department of Chemistry City University of Hong KongHong Kong 999077China Center of Super-Diamond and Advanced Films(COSDAF) City University of Hong KongHong Kong 999077China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

Bi is a promising.anode material for potassium-ion batteries(PIBs)due to its high theoretical ***,severe pulverization upon cycling limits its practical *** this work,we propose a new approach of using.metastable alloys with Bi *** Bi:Co and Bi:Fe alloys nanodots@carbon anode materials(Bi:Co and Bi:Fe@C)are synthesized for the first time via simple annealing of their metal-organic frameworks(MOF)*** prepared materials are demonstrated as ideal hosts for high-rate K-ion ***_(0.85)Co_(0.15)@C and Bi_(0.83)Fe_(0.17)@C electrodes respectively deliver superior 178 and 253 mAh·g^(−1)at 20 A·g^(−1),as well as stable cycling performance at 2 A·g^(−1).Ex situ scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(Xrd),and transmission electron microscopy(TEM)studies on Bi:Co@C indicate that the elemental Co separates out during the initial potassiation and stands during the following discharge/charge *** situ formed Co precipitates can act as(1)“conductive binders”as well as(2)“separators”to prevent the severe aggregation of adjacent active elemental Bi nanoparticles and(3)accelerate the potassiation/de-potassiation kinetics in elemental Bi precipitates after initial discharge/charge *** work could inspire the development of metal-type anodes.

关键词： metastable alloys metal anode potassium-ion battery metal-organic frameworks(MOF)-derived materials

Extension and Comparative Study of AUSM-Family Schemes for Compressible Multiphase Flow Simulations

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Communications in Computational Physics 2014年第8期16卷 632-674页

作者： Keiichi Kitamura Meng-sing.Liou Chih-Hao Chang NASA Glenn Research Center ClevelandOH 44135USA. Research Fellow of Japan Society for the Promotion of Science(JSPS) JAXA’s Engineering Digital Innovation(JEDI)Center3-1-1 YoshinodaiChuoSagamiharaJapan Previously at Nagoya University Furo-choChikusa-kuNagoyaAichi 464-8603 Japan Currently at Yokohama National University 79-5 TokiwadaiHodogaya-kuYokohama 240-8501Japan. Theofanous&Co Inc.Santa Barbara CA 93109USA

Several recently developed AUSM-family numerical flux functions(SLAU,SLAU2,AUSM+-up2,and AUSMPW+)have been successfully extended to compute compressible multiphase flows,based on the stratified flow model concept,by following two previous works:one by M.-***,C.-***,***,and ***[AIAA J.46:2345-2356,2008],in which AUSM+-up was used entirely,and the other by C.-***,and M.-***[***.225:840-873,2007],in which the exact Riemann solver was combined into AUSM+-up at the phase *** an extensive survey by comparing flux functions,the following are found:(1)AUSM+-up with dissipation parameters of Kp and Ku equal to 0.5 or greater,AUSMPW+,SLAU2,AUSM+-up2,and SLAU can be used to solve benchmark problems,including a shock/water-droplet interaction;(2)SLAU shows oscillatory behaviors[though not as catastrophic as those of AUSM+(a special case of AUSM+-up with Kp=Ku=0)]due to insufficient dissipation arising.from its ideal-gas-based dissipation term;and(3)when combined with the exact Riemann solver,AUSM+-up(Kp=Ku=1),SLAU2,and AUSMPW+are applicable to more challenging problems with high pressure ratios.

关键词： Multiphase flow two-fluid model AUSM-family stratified flow model

Electric Vehicle Charging Scheduling Strategy for Supporting Load Flattening Under Uncertain Electric Vehicle Departures

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Journal of Modern Power Systems and Clean Energy 2023年第5期11卷 1634-1645页

作者： Han Wang Mengge Shi Peng Xie Chun sing.Lai Kang Li Youwei Jia IEEE Department of Electrical and Electronic Engineering Southern University of Science and TechnologyShenzhen 518055China School of Electronic and Electrical Engineering University of LeedsLeedsLS29JTUK Brunel Interdisciplinary Power Systems Research Centre Department of Electronic and Electrical EngineeringBrunel University LondonLondon UB83PHUK

The scheduled electric vehicle(EV)charging flexibility has great potential in supporting the operation of power systems,yet achieving such benefits is challenged by the uncertain and user-dependent nature of EV charging *** research primarily focuses on modeling the uncertain EV arrival and battery status yet rarely discusses the uncertainty in EV *** this paper,we investigate the EV charging scheduling strategy to support load flattening at the distribution level of the utility grid under uncertain EV departures.A holistic methodology is proposed to formulate the unexpected trip uncertainty and mitigate its negative *** ensure computational efficiency when large EV fleets are involved,a distributed solution framework is developed based on the alternating direction method of multipliers(ADMM)*** numerical results reveal that unexpected trips can severely damage user convenience in terms of EV energy *** is further confirmed that by applying the proposed methodology,the resultant critical and sub-critical user convenience losses due to scheduled charging are reduced significantly by 83.5%and 70.5%,respectively,whereas the load flattening performance is merely sacrificed by 17%.

关键词： Electric vehicle(EV) EV fleet uncertain departure user convenience distributed solution

Contemporary outcomes in the detection of prostate cancer using.transrectal ultrasound-guided 12-core biopsy in sing.porean men with elevated prostate specific antigen and/or abnormal digital rectal examination

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Asian Journal of Urology 2015年第4期2卷 187-193页

作者： Alvin Lee sing.Joo Chia Yong Loo Lin School of Medicine National University of SingaporeSingapore Department of Urology Tan Tock Seng HospitalSingapore

Objective:Despite being the third commonest cancer in sing.porean men,there is a dearth of basic data on the detection rate of prostate cancer and post-procedure complication rates locally using.systematic 12-core *** objective is to evaluate prostate cancer detection rates using.12-core prostate biopsy based on serum prostate specific antigen(PSA)levels and digital rectal examination(DRE)findings in sing.porean men presenting to a sing.e tertiary *** secondary objective is to evaluate the complication rates of transrectal prostate ***:We retrospectively examined 804 men who underwent first transrectal-ultrasound(TRUS)guided 12-core prostate biopsies from January 2012 to April *** biopsies were performed on men presenting to a tertiary institution when their PSA levels were4.0 ng/mL and/or when they had suspicious DRE ***:Overall prostate cancer detection rate was 35.1%.Regardless of DRE findings,patients were divided into four subgroups based on their serum PSA levels:0e3.99 ng/mL,4.00 e9.99 ng/mL,10.00e19.99 ng/mL and20.00 ng/mL and their detection rates were 9.5%,20.9%,38.4% and 72.3%,*** detection rate of cancer based on suspicious DRE findings alone was 59.2% compared to 36.5% based on serum PSA cut-off of 4.0 ng/mL *** post-biopsy admission rate for sepsis was 1.5%.Conclusion:In conclusion,using.contemporary 12-core biopsy methods,the local prostate cancer detection rate based on serum PSA and DRE findings has increased over the past decade presumably due to multiple genetic and environmental ***-biopsy sepsis remains an important complication worldwide.

关键词： Digital rectal examination Oncology Prostate cancer Prostate specific antigen Transrectalultrasound Biopsy

A Multimodel Transfer-Learning-Based Car Price Prediction Model with an Automatic Fuzzy Logic Parameter Optimizer

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Computer Systems Science & Engineering 2023年第8期46卷 1577-1596页

作者： Ping-Huan Kuo sing.Yan Chen Her-Terng Yau Department of Mechanical Engineering National Chung Cheng UniversityChiayi62102TaiwanChina Advanced Institute of Manufacturing with High-Tech Innovations(AIM-HI) National Chung Cheng UniversityChiayi62102TaiwanChina

Cars are regarded as an indispensable means of transportation in *** studies have indicated that the automotive industry has witnessed remarkable advances and that the market of used cars has rapidly *** this study,a price prediction system for used BMW cars was *** parameters of used cars,including their model,registration year,and transmission style,were *** data obtained were then divided into three *** first subset was used to compare the results of each *** predicted values produced by the two algorithms with the most satisfactory results were used as the input of a fully connected neural *** second subset was used with an optimization algorithm to modify the number of hidden layers in a fully connected neural network and modify the low,medium,and high parameters of the membership function(MF)to achieve model ***,the third subset was used for the validation set during the prediction *** three subsets were divided using.k-fold cross-validation to avoid overfitting and selection *** conclusion,in this study,a model combining two optimal algorithms(i.e.,random forest and k-nearest neighbors)with several optimization algorithms(i.e.,gray wolf optimizer,multilayer perceptron,and MF)was successfully *** prediction results obtained indicated a mean square error of 0.0978,a root-mean-square error of 0.3128,a mean absolute error of 0.1903,and a coefficient of determination of 0.9249.

关键词： Used car price prediction transfer learning fuzzy logic machine learning optimization algorithm

Room temperature Ⅲ–Ⅴ nanolasers with distributed Bragg reflectors epitaxially grown on(001) silicon-on-insulators

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Photonics Research 2019年第9期7卷 1081-1086页

作者： YU HAN WAI KIT NG YING XUE KAM sing.WONG KEI MAY LAU Department of Electronic and Computer Engineering Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina Department of Physics and William Mong Institute of Nano Science and Technology Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina

Efficient, scalable, bufferless, and compact Ⅲ–V lasers directly grown on(001)-oriented silicon-on-insulators(SOIs) are preferred light sources in Si-photonics. In this article, we present the design and operation of Ⅲ–V telecom nanolaser arrays with integrated distributed Bragg reflectors(DBRs) epitaxially grown on industry-standard(001) SOI wafers. We simulated the mirror reflectance of different guided modes under various mirror architectures, and accordingly devised nanoscale DBR gratings to support high reflectivity around1500 nm for the doughnut-shaped TE01 mode. Building from InP/InGaAs nanoridges grown on SOI, we fabricated subwavelength DBR mirrors at both ends of the nanoridge laser cavities and thus demonstrated room-temperature low-threshold InP/InGaAs nanolasers with a 0.28 μm^2 cross-section and a 20 μm effective cavity length. The direct growth of these bufferless nanoscale Ⅲ–V light emitters on Si-photonics standard(001) SOI wafers opens future options of fully integrated Si-based nanophotonic integrated circuits in the telecom wavelength regime.

关键词： InGaAs InP SOI nanolasers with distributed Bragg reflectors epitaxially grown on Room temperature silicon-on-insulators Bragg

Robust N−k Security-constrained Optimal Power Flow Incorporating Preventive and Corrective Generation Dispatch to Improve Power System Reliability

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CSEE Journal of Power and Energy Systems 2023年第1期9卷 351-364页

作者： Liping Huang Chun sing.Lai Zhuoli Zhao Guangya Yang Bang Zhong Loi Lei Lai School of Automation Guangdong University of TechnologyGuangzhou 510006China School of Automation Guangdong University of TechnologyGuangzhou 510006Chinaand also with the Department of Electronic and Electrical EngineeringBrunel University LondonLondonUB83PHUK Center for Electric Power System and Energy Department of Electrical EngineeringTechnical University of DenmarkKongens Lyngby 2800Demark Zhaoqing Power Supply Bureau Guangdong Power Grid CompanyChina Southern Power GridZhaoqing 526020China

As extreme weather events have become more frequent in recent years,improving the resilience and reliability of power systems has become an important area of *** this paper,a robust preventive-corrective security-constrained optimal power flow(RO-PCSCOPF)model is proposed to improve power system reliability under N−k *** the short-term emergency limit(STL)and the long-term operating limit(LTL)of the post-contingency power flow on the branch are *** with the existing robust corrective SCOPF model that only considers STL or LTL,the proposed ROPCSCOPF model can achieve a more reliable generation dispatch *** addition,this paper also summarizes and compares the solution methods for solving the N−k SCOPF *** computational efficiency of the classical Benders decomposition(BD)method,robust optimization(RO)method,and line outage distribution factor(LODF)method are investigated on the IEEE 24-bus Reliability Test System and 118-bus *** results show that the BD method has the worst computation *** RO method and the LODF method have comparable ***,the LODF method can only be used for the preventive SCOPF and not for the corrective *** RO method can be used for both.

关键词： Benders cut bender decomposition line outage distribution factor N−k security criterion optimal power flow power system reliability resilience robust optimization

Pushing the limits of existing plasma focus towards 1016 fusion neutrons with Q=0.01

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Plasma Science and Technology 2022年第11期24卷 47-53页

作者： sing.LEE Institute for Plasma Focus Studies 32 Oakpark DriveChadstone VIC3148Australia Physics Department University of MalayaKuala Lumpur 50603Malaysia INTI International University Nilai 71800Malaysia Fuse Energy Technologies Napierville QC J0J 1L0Canada

Existing conventional megajoule plasma focus machines with 2–3 MA are producing fusion neutron yields of several times 10^(11) in deuterium operation,the fusion yields predominantly being the beam-gas *** the current to 10 MA and using.50%–50%D-T mixture will scale the neutron yield towards 10^(16) D-T fusion *** this work,we derive the Lawson criterion for plasma focus devices with a beam-target fusion neutron mechanism,so that we may glimpse what future technological advancements are needed for a break-even Q=1 plasma *** perform numerical experiments with a present-day feasible 0.9 MV,8.1 MJ,11 MA machine operating in 100 Torr in 50%–50%D-T *** Lee Code simulation gives a detailed description of the plasma focus dynamics through each phase,and provides plasma and yield parameters which show that out of 1.1×10^(19) fast beam ions produced in the plasma focus pinch,only 1.24×10^(14) ions take part in beam-target fusion reactions within the pinch,producing the same number of D-T *** remnant beam ions,numbering at least 10^(19),exit the focus pinch at 1.9 MeV,which is far above the 115 keV ion energy necessary for an optimum beam-target *** propose to regain the lost fusion rates by using.a high-pressure D-T-filled drift-tube to attenuate the energy of the remnant beam ions until they reach the energy for the optimum fusion *** a fusion enhancement tube would further harvest beam-target fusion reactions by increasing.the interaction path length(1 m)at increased interaction density(6 atm).A gain factor of 300 is conservatively estimated,with a final yield of 3.7×10^(16) D-T neutrons carrying kinetic energy of 83.6 kJ,demonstrating Q=0.01.

关键词： plasma focus simulation neutron enhancement fusion harvester plasma focus