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Breakdown of effective medium theory:A study of photonic spin Hall effect in deep-subwavelength all-dielectric multilayers

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 173-174页

作者： Yongmin liu Department of Mechanical and Industrial Engineering Northeastern UniversityBoston 02115USA Department of Electrical and Computer Engineering Northeastern UniversityBoston 02115USA

Effective medium theory(EMT)has been widely applied in material science,electromagnetics and photonics to determine the effective material properties for inhomogeneous composites comprising subwavelength *** versatility of this foundational approach has been established through its application in classical Maxwell-Garnet models,which encompass relatively simple structures。

关键词： composites theory dielectric

A REFINEMENT OF THE SCHWARZ-PICK ESTIMATES AND THE CARATHéODORY METRIC IN SEVERAL COMPLEX VARIABLES

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Acta Mathematica Scientia 2024年第4期44卷 1337-1346页

作者： Xiaosong liu Taishun liu School of Mathematics and Statistics Lingnan Normal UniversityZhanjiang 524048China Department of Mathematics Huzhou UniversityHuzhou 313000China

In this article,we first establish an asymptotically sharp result on the higher order Fréchet derivatives for bounded holomorphic mappings f(x)=f(0)+∞∑s=1Dskf(0)(x^(sk))/(sk)!:B_(X)→B_(Y),where B_X is the unit ball of *** next give a sharp result on the first order Fréchet derivative for bounded holomorphic mappings F(X)=F(0+)∞∑s=KD^(s)f(0)(x^(8)/s!):B_(X)→B_(Y),where B_(X)is the unit ball of *** results that we derive include some results in several complex variables,and extend the classical result in one complex variable to several complex variables.

关键词： refined Schwarz-Pick estimate bounded holomorphic mapping Carathéodory metric first order Fréchet derivative higher order Fréchet derivatives

Fatigue-resistant sliding ferroelectricity

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Science China Materials 2024年第10期67卷 3417-3418页

作者： Zheng liu School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore

The direction of spontaneous polarization in ferroelectricity can be reoriented by an external electric *** special feature of ferroelectricity is important candidates for fabricating advanced nonvolatile random-access memory[1].However,repeatedly switching polarization induces the ferroelectric device performance degenerates due to a reduction of polarization.

关键词： polarization ferroelectric field.

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钩子技术在计算机基础教学中的应用

微计算机应用 2006年第6期27卷 751-753页

作者：刘凤鸣谢深泉湘潭大学信息工程学院湖南411105

钩子技术是Windows系统中功能十分强大的技术,通过它可以对几乎所有的Win32消息进行拦截、监视、处理。利用钩子技术可以在许多计算机上机考试系统中实现异常强大的功能,本文主要介绍了一个使用全局CBT钩子的考试系统,并体现钩子技术的... 详细信息

钩子技术是Windows系统中功能十分强大的技术,通过它可以对几乎所有的Win32消息进行拦截、监视、处理。利用钩子技术可以在许多计算机上机考试系统中实现异常强大的功能,本文主要介绍了一个使用全局CBT钩子的考试系统,并体现钩子技术的优越性。

关键词：钩子计算机基础教学钩子类型 A函数消息拦截计算机考试

加卸荷工况对注浆砂土-混凝土接触面剪切特性影响

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工程科学与技术 2022年第5期54卷 103-110页

作者：吴悦刘丰铭赵春风侯忠伟王有宝涂义亮韩达光重庆交通大学山区桥梁与隧道工程国家重点实验室重庆400074 重庆交通大学土木工程学院重庆400074 同济大学土木工程学院上海200092 重庆鲁汶智慧城市与可持续发展研究院重庆401135 重庆建筑工程职业学院重庆400072 成都市城乡建设委员会四川成都610094

土-结构物接触面力学特性是岩土工程领域研究的重点与热点问题之一,揭示其机理有利于促进对桩基础、挡土墙等结构物承载性能的认识。本文采用自主设计研发的注浆设备和室内后注浆试验方法,对3种注浆量和4种加、卸荷工况下,共计28组注浆... 详细信息

土-结构物接触面力学特性是岩土工程领域研究的重点与热点问题之一,揭示其机理有利于促进对桩基础、挡土墙等结构物承载性能的认识。本文采用自主设计研发的注浆设备和室内后注浆试验方法,对3种注浆量和4种加、卸荷工况下,共计28组注浆和未注浆大型接触面进行直剪试验,分析不同加、卸荷工况对注浆砂土-混凝土接触面力学特性和剪切影响范围的影响。结果表明:注浆可逐渐消除加卸荷产生的接触面初始剪切模量和剪切应力差异。未注浆接触面未出现软化;注浆接触面呈现软化现象,并且软化出现在剪切法向应力较小的卸荷接触面剪切过程中。后注浆主要通过提高接触面等效黏聚力,改善接触面力学特性,对接触面等效内摩擦角无明显影响。同一注浆量下,浆液对无卸荷工况接触面等效黏聚力的改善效果优于卸荷工况;卸荷工况的接触面剪切影响范围略大于无卸荷工况;加卸荷和注浆工况下,接触面剪切影响范围与接触面峰值剪切应力呈正相关。同一剪切法向应力下,注入浆液,通过压密注浆形成浆块,增大接触面混凝土板的粗糙度,改善卸荷接触面剪切特性;通过浆液渗透形成浆土混合体,对无卸荷接触面处土体特性进行改善。研究成果可为实际工程中桩基工程后注浆提供指导。

关键词：接触面卸荷剪切带力学特性注浆

The important role of Turbidity Maximum Zone in sedimentary dynamic of estuarine mangrove swamp

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Frontiers of Earth Science 2024年第1期18卷 219-226页

作者： Tao liu Ying liu Baoqing HU Key laboratory of Environment Change and Resources Use in Beibu Gulf(Ministry of Education) Nanning Normal UniversityNanning 530001China School of Civil Engineering and Architecture Guangxi UniversityNanning 530004China

Sedimentation is a key process affecting wetland sustainability and carbon burial *** context of sea level rise,climate change and human activities,further understanding about the sedimentary dynamic in wetland is critical in predicting the landscape evolution or the change in carbon burial *** this study,based on the field hydrological observation in a mangrove system in the Nanliu River estuary,we found the net flux of suspended sediment to mangrove is 39−72 kg/m in tidal cycles with Turbidity Maximum Zone(TMZ)forming in surface layer and only is 9−18 kg/m in tidal cycles without *** higher net flux of suspended sediment to mangrove in tidal cycles with TMZ forming in surface layer is attributed to high SSC in rising tide and intense flocculation in *** significant discrepancy in sedimentation rate in the mangrove patches also can be explained by the probability of TMZ forming in the surface layer of *** future,rapid sea level rising may lead to the change of TMZ pattern in estuary,which will result in non-negligible variation in sedimentation rate in *** to the present data of sedimentation rate in wetlands,the fragility of wetlands in river estuary may be miscalculated.

关键词： mangrove wetland sedimentation Turbidity Maximum Zone Nanliu River

Compact multilayer liquid crystal polymer lowpass filter with 8-shaped inductor

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The Journal of China Universities of Posts and Telecommunications 2024年第3期31卷 80-86页

作者： liu Weihong Wang Guoxiu liu Qingran School of Electronic Engineering Xi'an University of Posts and TelecommunicationsXi'an 710121China

Lumped element lowpass filter(LPF)for ultra-high frequency(UHF)radio frequency(RF)front-end system is presented based on multilayer liquid crystal polymer(LCP).The lumped element LPF can achieve miniaturization and one transmission zero on the stopband by the 8-shaped *** lumped element LPF is fabricated on a 4-layer LCP substrate with a compact size of 9 mm×14 mm×0.193 *** measured cut off frequency of the lumped element LPF is 0.5 GHz with insertion loss(IL)less than 0.37 *** measured and simulated results suggest that it is a possible candidate for the application of UHF RF front-end system.

关键词： lowpass filter(LPF) multilayer liquid crystal polymer(LCP) miniaturization 8-shaped inductor

A compact bimorph rotary piezoelectric actuator with customized small power supply

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Science China(Technological Sciences) 2024年第4期67卷 1185-1195页

作者： DENG Jie liu DaQing WANG WeiYi liu YingXiang School of Mechatronics and Engineering Harbin Institute of TechnologyHarbin 150001China

Inertial piezoelectric actuators are widely applied in precision devices with simple structure and accurate ***,existing inertial piezoelectric actuators still face the challenges of rollback motion and bulky power *** this work,an alternate excitation strategy and a customized small power supply for a bimorph rotary piezoelectric actuator(BRPA)are proposed to solve the *** BRPA prototype is designed with a bipedal symmetrical structure,measuring 35 mm in height and 32 mm in diameter,which has a maximum rotation velocity of 0.247 rad/s and a resolution of 0.66μ*** to the bipedal symmetrical structure,the friction directions between the driving feet and the rotor can be coordinated to suppress the *** rollback ratio is almost zero when the phase difference of the exciting signal is set as 180°.The customized power supply is designed and manufactured,whose size is 58 mm×56 mm×46 *** can output signals for the single step mode and the continuous mode,and they are adopted to excite BRPA to achieve a small stroke with one single step and a large stroke with continuous step,***,an experimental system for optical fiber alignment is developed based on the BRPA and the customized small power supply,the experiment has verified the practicability of this work in the precision fields,especially in the miniaturized precision systems.

关键词： inertial piezoelectric actuator customized small power supply single step mode continuous mode rollback suppression miniaturized precision system

Automated,economical,and environmentally-friendly asphalt mix design based on machine learning and multi-objective grey wolf optimization

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第3期11卷 381-405页

作者： Jian liu Fangyu liu Linbing Wang Department of Civil and Environmental Engineering Virginia Polytechnic Institute and State UniversityBlacksburgVA 24061USA School of Environmental CivilAgricultural and Mechanical EngineeringUniversity of GeorgiaAthensGA 30602USA Illinois Center for Transportation Department of Civil and Environmental EngineeringUniversity of Illinois Urbana-ChampaignUrbanaIL 61801USA

The increasing impact of the greenhouse effect on ecosystems is prompting transportation agencies to seek methods for reducing CO_(2)emissions during pavement construction and ***,the laboratory mix design process,which involves selecting aggregate gradation and binder content,is time-consuming and *** accelerate the traditional mix design procedure,this study presented a mix design procedure that can automatically determine gradation and binder content based on machine learning(ML)and a meta-heuristic ***,ML approaches were employed to model the relationship between volumetric properties(mixture bulk specific gravity(Gmb)and air void(VV))and both mixture component properties and mixture proportion,based on a dataset collected from literature with 660 mixture *** with the prediction of ML models and the modified multi-objective grey wolf optimization(MOGWO)algorithm,an automatic asphalt mix design was proposed to pursue three goals,including VV,cost,and CO_(2)*** results indicated that least squares support vector regression(LSSVR)and e Xtreme gradient boosting(XGBoost)achieved the highest prediction accuracies(correlation coefficient:0.92 for VV and 0.96 for Gmb).The MOGWO algorithm successfully found the 26 optimal mix designs for the case of VV *** ***_(2)*** to the traditional laboratory design,the optimal mixture with VV of4%achieves a cost saving of 2.46%and a reduction of 4.03%in carbon *** volumetric properties of the mixtures output by the approach also align closely with values measured in a laboratory.

关键词： Asphalt mix design Machine learning MOGWO CO_(2)emission Volumetric properties