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Transactions of Nonferrous Metals society of China 2024年第11期34卷 3629-3649页

作者： Rania EhaMMAM Engie MsAFWAT s.ha aabdel-gawad Madiha sHOEIB shimaa EL-haDAD Faculty of Engineering Modern University for Technology and Information(MTI)Cairo 11585Egypt Restorative and Dental Materials Department National Research CentreGiza 12622Egypt Chemistry Department Faculty of ScienceCairo UniversityGiza 12613Egypt Central Metallurgical Research and Development Institute CMRDIP.O.87Helwan 11421Egypt

Integrating titanium-based implants with the surrounding bone tissue remains *** study aims to explore the impact of different anodization voltages(20−80 V)on the surface topography of two-phase(α/β)Ti alloys and to produce TiO_(2) films with enhanced bone formation *** electron microscopy coupled with energy dispersive spectroscopy(sEM−EDs)and atomic force microscopy(AFM)were applied to investigate the morphological,chemical,and surface topography of the prepared alloys and to confirm the growth of hydroxyapatite(ha)on their *** disclosed that the surface roughness of TiO_(2) films formed on Ti−6Al−7Nb alloys was superior to that of Ti−6Al−4V ***−6Al−7Nb alloy anodized at 80 V had the highest yields of ha after immersion in simulated body fluid with enhanced ha surface *** developed ha layer had a mean thickness of(128.38±18.13)μm,suggesting its potential use as an orthopedic implantable material due to its promising bone integration and,hence,remarkable stability inside the human body.

关键词： material science electrochemical anodization process atomic force microscopy α/βTi alloys hydroxyapatite deposition

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Current state-of-the-art review of footwear–ground friction

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Friction 2024年第10期12卷 2188-2204页

作者： David REBENDA Tomáš s.ha Footwear Research Centre University InstituteTomas Bata University in ZlinZlin 76001Czech Republic Faculty of Mechanical Engineering Brno University of TechnologyBron 61600Czech Republic

The most important role of footwear is to ensure safe,functional walking,and foot *** the proper functionality of not only the work shoes,the anti-slip behavior of the shoe under various conditions and environments plays an important role in the prevention of slips,trips,falls,and consequent *** article is intended to review the current understanding of the frictional mechanisms between shoe outsoles and various counterfaces that impact the evaluation of outsole *** research focuses on the mechanisms driving outsole friction on different ground surfaces or the definition and description of parameters that influence outsole ***,the review discusses the effect of various surface contaminants on footwear ***,challenges and outlooks in the field of footwear outsoles are briefly mentioned.

关键词： shoe outsole composite slipperiness coefficient of friction(COF) adhesion safe walk

Non-expansive Mappings and Iterative Methods in Uniformly Convex Banach spaces

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Acta Mathematica sinica,English series 2004年第5期20卷 829-836页

作者： ha|YunZHOU Dept.ofMath. ShijiazhuangMechanicalEngineeringCollegeShijiazhuang050003P.R.China

In this article,we will investigate the properties of iterative sequence for non-expansive mappings and present several strong and weak convergence results of successive approximations to fixed points of non-expansive mappings in uniformly convex Banach *** results presented in this article generalize and improve various ones concerned with constructive techniques for the fixed points of non-expansive mappings.

关键词： Non-expansive mapping Mann and lshikawa iteration schemes Convergence theorem Uniformly convex Banach space

support vector machine based machine learning method for Gs 8QAM constellation classification in seamless integrated fiber and visible light communication system

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science China(Information sciences) 2020年第10期63卷 182-193页

作者： Wenqing NIU Yinaer ha Nan CHI Key Laboratory for Information science of Electromagnetic Waves (MoE) Fudan University

Visible light communication(VLC) network over optical fiber has become a potential candidate in ultra-high speed indoor wireless communication. To mitigate signal distortion accumulated in optical fiber and VLC channel, we present to utilize support vector machine(sVM) for constellation classification in two kinds of geometrically-shaped 8 QAM(quadrature amplitude modulation) seamless integrated fiber and VLC system. We introduce 4 sub-bands to simulate multi-user. Experimental results show that system performance can be significantly improved, and transmission at-2.5 dB m input optical power under 7%forward error correction(FEC) threshold can be realized employing Circular(7, 1) geometrically-shaped8 QAM and sVM. At overall capacity of 960 Mbps, Q-factor increases by up to 11.5 dB.

关键词： visible light communication VLC support vector machine sVM geometrically shaping Gs VLC network constellation classification

suzuki Reaction of Aryl Bromides Using a Phosphine-Free Magnetic Nanoparticle-supported Palladium Catalyst

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催化学报 2011年第11期32卷 1667-1676页

作者： Nghia T. BUI Trung B. DANG ha V. LE Nam T. s. PhaN Department of Chemical Engineering HCMC University of Technology VNU-HCM 268 Ly Thuong Kiet Distriet 10 Ho Chi Minh City Viet Nam

A palladium catalyst immobilized on superparaganetic nanoparticles was prepared with a palladium loading of 0.30 mmol/g. The catalyst was characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, Fourier transform infrared, atomic absorption spectrophotometry, and nitrogen adsorption. The immobilized palladium catalyst was an efficient catalyst without added phosphine ligands for the suzuki cross-coupling reaction of several aryl bromides with phenylboronic acid. The recovery of catalyst was simply by magnetic decantation in the presence of a magnet. The immobilized palladium catalyst can be reused many times without significant degradation in catalytic activity. No leaching of active palladium species into the reaction solution was detected.

关键词： superparamagnetic nanoparticle suzuki reaction palladium aryl bromide

Low-temperature synthesis of Fe_(2)(MoO_(4))_(3) nanosheets: A cathode for sodium ion batteries with kinetics enhancement

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Nano Research 2021年第11期14卷 3977-3987页

作者： ha Tran Huu N.s.M.Viswanath Ngoc Hung Vu Jong-Won Lee Won Bin Im Division of Materials science and Engineering Hanyang University222Wangsimni-roSeongdong-guSeoul04763Republic of Korea school of Materials science and Engineering Chonnam National University77 Yongbong-roBuk-guGwangju61186Republic of Korea Falcuty of Biotechnology Chemistry and Environmental EngineeringPhenikaa UniversityHanoi10000Vietnam A&A Green Phoenix Group Phenikaa Research and Technology Institute(PRATI)167 Hoang NganHanoi10000Vietnam Department of Energy science and Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)333 Techno Jungang-daeroHyeonpung-eupDalseonggunDaegu42988Republic of Korea

sodium ion batteries (sIBs) are alternatives to lithium ion batteries (LIBs), and offer some significant benefits such as cost reduction and a lower environmental impact;however, to compete with LIBs, further research is required to improve the performance of sIBs. In this study, an orthorhombic Na super ionic conductor structural Fe_(2)(MoO_(4))_(3) nanosheet with amorphous-crystalline core-shell alignment was synthesized using a facile low-temperature water-vapor-assisted solid-state reaction and applied as a cathode material for sIBs. The obtained material has a well-defined three-dimensional stacking structure, and exhibits a high specific capacity of 87.8 mAh·g^(−1) at a current density of 1 C = 91 mA·g^(−1) after 1,000 cycles, which is due to the considerable contribution of extra surface-related reaction such as the pseudo-capacitive process. This material shows significantly improved cycling and rated behavior as well as enhanced performance under high- and low-temperature conditions, as compared to the same materials prepared by the conventional high-temperature solid-state reaction. This enhancement is explained by the unique morphology in combination with the improved kinetics of the electrochemical reaction due to its lower charge transfer resistance and higher sodium ion conductivity.

关键词： low-temperature synthesis cathode sodium ion batteries kinetics Na+super ionic conductor(NAsICON)

summer extreme precipitation patterns and synoptic-scale circulation precursors over the Tibetan Plateau

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science China Earth sciences 2024年第5期67卷 1625-1638页

作者： Zhiyuan DING Yao ha Zhong ZHONG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China Key Laboratory for Virtual Geographic Environment School of Geography ScienceNanjing Normal UniversityNanjing 210023China Jiangsu Collaborative Innovation Center for Climate Change School of Atmospheric SciencesNanjing UniversityNanjing 210023China

In the context of global warming,the extreme summer precipitation over the Tibetan Plateau(TP)has changed *** this study,the summer(June–August)extreme precipitation on the TP was classified into three spatial types by applying the K-means clustering method to the Third Pole Region long time-series high-resolution(1/30°)precipitation dataset(TPHi Pr,1979–2020).The characteristics of the circulation anomalies and precursors corresponding to the extreme precipitation on the TP in summer during 1979–2020 were *** results showed that the summer extreme precipitation of the TP can be categorized into northwestern(NW),southeastern(sE),and southern Himalayan(Hs)types based on extreme precipitation *** NW and sE types are mainly influenced by anomalous signals in the mid-to-high latitude regions upstream of them,whereas the Hs type is controlled by the localized subtropical anomalous *** the 8th day before the onset of the NW type,an anomalous cyclone was observed in the western Atlantic Ocean(60°W,50°N),which triggered the west-to-east quasi-latitudinal propagation of Rossby *** the onset day of the NW type,the upper troposphere showed positive-negative-positive geopotential height anomalies along the latitudinal 40°N from the Caspian sea,the western part of Xinjiang,to the northeastern *** entered from the Arabian sea along the southeastern edge of the anomalous cyclone on the southwestern TP and converged in the northwestern *** to the NW type,the precursors of the sE type appeared at higher latitudes and were more *** the 8th day before the onset of the sE type,an anomalous cyclone occurred near Greenland(60°W,70°N)and excited Rossby waves propagating *** the onset day of the sE type,the upper troposphere showed negative-positive-negative geopotential height anomalies across Eurasia from the Ural Mountains and the Iranian Plateau to the northern TP in the northwest-southeast directi

关键词： Tibetan Plateau summer extreme precipitation Atmospheric circulation anomaly Precursor Teleconnection wave train

Propulsion Modeling and Analysis of a Biomimetic swimmer

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Journal of Bionic Engineering 2010年第3期7卷 259-266页

作者： Ngoc san ha Nam seo Goo smart Microsystem Research Lab. Department of Advanced Technology FusionKonkuk University

We have studied a biomimetic swimmer based on the motion of bacteria such as Escherichia coli (E. coli) theoretically andexperimentally. The swimmer has an ellipsoidal cell body propelled by a helical filament. The performance of this swimmer wasestimated by modeling the dynamics of a swimmer in viscous fluid. We applied the Resistive Force Theory (RFT) on this modelto calculate the linear swimming speed and the efficiency of the model. A parametric study on linear velocity and efficiency tooptimize the design of this swimmer was demonstrated. In order to validate the theoretical results, a biomimetic swimmer wasfabricated and an experiment setup was prepared to measure the swimming speed and thrust force in silicone oil. The experimentalresults agree well with the theoretical values predicted by RFT. In addition, we studied the flow patterns surrounding thefilament with a finite element simulation with different Reynolds number (Re) to understand the mechanism of propulsion. Thesimulation results provide information on the nature of flow patterns generated by swimming filament. Furthermore, the thrustforces from the simulation were compared with the thrust forces from theory. The simulation results are in good agreement withthe theoretical results.

关键词： biomimetic microrobots swimming microrobots propulsion of flagella flow visualization medical application

A novel benzo[4,5]furo[3,2-d]pyrimidine-based host as a n-type host for blue phosphorescent organic light-emitting diodes

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science China Materials 2022年第4期65卷 1028-1033页

作者： Junsu ha Junseop Lim Jun Yeob Lee school of Chemical Engineering Sungkyunkwan University2066Seobu-roJangan-guSuwon-siGyeonggi-do16419Republic of Korea

An electron-transport-type host was synthesized using a benzo[4,5]furo[3,2-d]pyrimidine(BFP)core to develop a high triplet energy *** host was designed to have both the tetraphenylsilyl blocking group and the hole-transport-type carbazole *** the device application,the host was used as an electron-transport-type host mixed with a hole-transport-type 3,3'-di(9H-carbazol-9-yl)-1,1†-biphenyl(mCBP)host in the blue phosphorescent organic light-emitting diodes(PhO-LEDs)doped with a[[5-(1,1-dimethylethyl)-3-phenyl-1H-imidazo[4,5-b]pyrazin-1-yl-2(3H)-ylidene]-1,2-phenylene]bis-[[6-(1,1-dimethylethyl)-3-phenyl-1H-imidazo[4,5-b]pyrazin-1-yl-2(3H)-ylidene]-1,2-phenylene]iridium(Ir(cb)3)blue *** a result,the mCBP:CzBFPmsi mixed host showed high external quantum efficiency over 20%at 1000 cd m^(−2) and low efficiency roll-off in the blue PhOLEDs.

关键词： blue device host efficiency lifetime

A procedural footprint enhancement of global topographic surface with multiple levels of detail

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International Journal of Digital Earth 2020年第4期13卷 527-545页

作者： Lukáš Brůha Jan Kolář Faculty of science Department of Applied Geoinformatics and CartographyCharles University in PraguePragueCzech Republic Grifinor Project CopenhagenDenmark

Virtual globes are technologies for visual navigation through a threedimensional,multi-resolution model of the entire *** representations used in virtual globes,however,lack geometric flexibility at high-resolution levels of the planet-wide terrain *** is a problem especially if boundaries between individual geospatial features and the terrain are important.A novel integration of individual polygonal boundaries with a specific multi-resolution representation of the planet-wide terrain is developed in this *** the preparation stage,the integration relies on an original simplification algorithm applied to the polygonal boundaries between geospatial features and the *** output is a multiple level-of-detail(LOD)geometry,which can be combined with a known multi-LOD representation of the terrain that uses run-time *** data representation is suitable for storage in existing database systems,avoids any data redundancy across LODs,and is even independent of the subdivision schema that partitions the planet’s surface for the sake of dealing with *** runtime,a novel reconstruction algorithm stitches geometric parts from different LODs together in a manner that augments the multi-LOD representation of the *** a certain proximity range from a given position,the method reconstructs a scene that preserves topological relations between the boundaries of geospatial features with the *** method also guarantees that certain nearest proximity to the given position consists of the best geometries that correspond to the original *** properties of the method close up the gap between a mere exploratory visualization of static,pre-generated models and the models supporting geospatial analysis,which is deemed crucial for applications in Geographic Information systems,Building Information Modelling and other software industries.A prototype implementation and experiment results that prove this method are also prese

关键词： Feature-based topography multiple level-of-detail procedural modeling vector data organization geometry reconstruction