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In vivo study of corneal responses to increased intraocular pressure loading

Eye and Vision 2015年第1期2卷 177-186页

作者： Ahmed Elsheikh charles W.McMonnies charles Whitford Gavin C.Boneham School of Engineering University of LiverpoolBrownlow HillLiverpool L693GHUK National Institute for Health Research(NIHR)Biomedical Research Centre Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of OphthalmologyLondonUK School of Optometry and Vision Science University of New South WalesSydneyAustralia

Background:The cornea is responsible for two-thirds of the eye's refractive power which is a function of the shape and refractive *** aim of this present study is to examine human eyes in vivo for corneal shape changes in response to short-term elevation in intraocular ***:Videokeratographic and tonometric assessments at baseline were compared with the same assessments when intraocular pressure was elevated to approximately double(199±22%)the baseline levels using ophthalmodynamometer applanation of the *** maps of the cornea and limbus were created by combining topographical assessments for central,nasal,temporal,inferior and superior *** finiteelement simulations were custom built for each subject and the stiffness distribution across corneal surface modified to achieve matches between simulated and experimental ***:The stiffness distributions required to achieve simulation-experimental matches showed a consistent trend with the 2.5 mm annulus bounded by the limbus showing a mean stiffness reduction of 47.3±10.8%compared with the central cornea(P=0.001).Conclusions:Corneal structure appears to provide the central cornea with a greater stiffness compared with the peripheral cornea and associated greater tolerance to elevation in intraocular pressure,consistent with the need for stable corneal refraction and *** method adopted to examine corneal biomechanical performance in vivo may have applications in additional studies.

关键词： Corneal biomechanics Topography Numerical simulation

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Hydrometallurgical detoxification and recycling of electric arc furnace dust

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International Journal of Minerals,Metallurgy and Materials 2023年第11期30卷 2076-2094页

作者： Yang Xue Xiaoming Liu Chunbao(charles)Xu Yonghui Han State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing 100083China School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Department of Chemical&Biochemical Engineering Western UniversityLondonON N6A 5B9Canada Hebei Technology Innovation Centre of Solid Wastes Utilization Hebei University of Science and TechnologyShijiazhuang 050091China

Electric arc furnace dust(EAFD)is a hazardous waste but can also be a potential secondary resource for valuable metals,such as Zn and *** the increased awareness of carbon emission reduction,energy conservation,and environmental protection,hydrometallurgical technologies for the detoxification and resource use of EAFD have been developing *** work summarizes the generation mechanisms,compositions,and characteristics of EAFD and presents a critical review of various hydrometallurgical treatment methods for EAFD,e.g.,acid leaching,alkaline leaching,salt leaching,and pretreatment–enhanced leaching ***,the phase transformation mechanisms of zinc-containing components in acid and alkali solutions and pretreatment processes are ***,two novel combined methods,i.e.,oxygen pressure sulfuric acid leaching combined with composite catalyst preparation,and synergistic roasting of EAFD and municipal solid waste incineration fly ash combined with alkaline leaching,are proposed,which can provide future development directions to completely recycling EAFD by recovering valuable metals and using zinc residue.

关键词： hazardous waste recycling separation zinc hydrometallurgical technologies

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Hybrid Cellular Automaton-Parabolic Thick Needle model for equiaxed dendritic solidification

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Journal of Materials Science & Technology 2022年第29期124卷 26-40页

作者： Romain Fleurisson Oriane Senninger Gildas Guillemot charles-André Gandin MINES ParisTech PSL Research UniversityCEMEF UMR CNRS 7635CS1020706904 Sophia AntipolisFrance

A hybrid Cellular Automaton(CA)-Parabolic Thick Needle(PTN)model is developed for the simulation of an equiaxed dendritic *** is implemented by solving conservation equations with the Finite Element(FE)method at two *** the scale of the microstructure,dendritic branches are approximated by a network of *** solute field is computed in the liquid using a FE mesh with minimum size smaller than the diffusion length ahead of the dendrite tips,giving access to a detailed description of each dendrite tip growth velocity as well as solutal interactions between *** the simulation domain scale,volume averaged heat and solute transfers are solved on a coarser FE *** average volumetric fraction of phases is deduced from a field giving the fraction of dendritic microstructure together with a microsegregation *** the PTN themselves grow on CA cells,the dendrite tip growth velocity is transferred to the vertices of the polygon associated to the CA growth ***,the field giving the fraction of dendritic microstructure is deduced from the fraction of CA cells part of the mushy zone,which include cells containing PTN *** of the new multiple scale CAPTN model include solutal interaction between dendrite branches together with long range transfer of heat and solute mass,together with the role of latent heat release on equiaxed solidification.

关键词： Solidification Dendrite growth law Multiscale Finite element method

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Multi-length scale modeling of carburization,martensitic microstructure evolution and fatigue properties of steel gears

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Journal of Materials Science & Technology 2020年第14期47卷 157-165页

作者： Edward charles Henry Crawford O’Brien Hemantha Kumar Yeddu School of Engineering Newcastle UniversityNewcastle upon TyneNE17RUUnited Kingdom

Multi-length scale modeling is performed to(i)predict the carburized case depth of SAE8620 steel gears by solving the Fick’s second law of diffusion,(ii)model the martensitic microstructure evolution in a grain inside the carburized case as well as to study the effect of stress cycling on retained austenite(RA)and martensite using a 3D phase-field model,(iii)simulate the effect of carburization and different RA contents on macroscale fatigue behavior of SAE8620 steel spur gear using the finite element *** diffusion model predicts that the case depth increases with increasing heat treatment time and *** phase-field simulations show that RA can transform to martensite during fatigue loading,where the extent of the transformation will depend on the type of stresses applied,*** in a high stress regime or low stress regime of fatigue *** transformation of martensite to austenite is also observed in low RA sample under high stress *** macroscale simulations show that the carburized case with high RA gives rise to better fatigue life compared to that with low RA.

关键词： Phase-field model Martensitic transformation Microstructure Gear steel Carburization

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Measuring,processing,and generating partially coherent light with self-configuring optics

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Light(Science & Applications) 2024年第11期13卷 2726-2733页

作者： charles Roques-Carmes Shanhui Fan David A.B.Miller 1E.L.Ginzton Laboratory Stanford University348 Via PuebloStanfordCA 94305USA

Optical phenomena always display some degree of partial coherence between their respective degrees of *** coherence is of particular interest in multimodal systems,where classical and quantum correlations between spatial,polarization,and spectral degrees of freedom can lead to fascinating phenomena(e.g.,entanglement)and be leveraged for advanced imaging and sensing modalities(e.g.,in hyperspectral,polarization,and ghost imaging).Here,we present a universal method to analyze,process,and generate spatially partially coherent light in multimode systems by using self-configuring optical *** method relies on cascaded self-configuring layers whose average power outputs are sequentially *** optimized,the network separates the input light into its mutually incoherent components,which is formally equivalent to a diagonalization of the input density *** illustrate our method with numerical simulations of Mach-Zehnder interferometer arrays and show how this method can be used to perform partially coherent environmental light sensing,generation of multimode partially coherent light with arbitrary coherency matrices,and unscrambling of quantum optical *** provide guidelines for the experimental realization of this method,including the influence of losses,paving the way for self-configuring photonic devices that can automatically learn optimal modal representations of partially coherent light fields.

关键词： coherent modal generating

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Stable reinforcement learning with recurrent neural networks

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控制理论与应用（英文版） 2011年第3期9卷 410-420页

作者： James Nate KNIGHT charles ANDERSON Department of Computer Science Colorado State UniversityFort CollinsCO 80523U.S.A

In this paper,we present a technique for ensuring the stability of a large class of adaptively controlled *** combine IQC models of both the controlled system and the controller with a method of filtering control parameter updates to ensure stable behavior of the controlled system under adaptation of the *** present a specific application to a system that uses recurrent neural networks adapted via reinforcement learning *** work presented extends earlier works on stable reinforcement learning with neural ***,we apply an improved IQC analysis for RNNs with time-varying weights and evaluate the approach on more complex control system.

关键词： Stability analysis Integral quadratic constraint Recurrent neural network Reinforcement learning Linear matrix inequality

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Sirtuins are not conserved longevity genes

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Life Metabolism 2022年第2期1卷 122-133页

作者： charles Brenner Department of Diabetes&Cancer Metabolism Beckman Research Institute of City of HopeDuarteCA 91010 USA

It is central to biology that sequence conservation suggests functional *** longevity is an emergent property of selected traits that integrates capacities to perform physical and mental functions after reproductive *** the yeast SIR2 gene was nominated as a longevity gene based on extended replicative longevity of old mother cells,this is not a selected trait:SIR2 is selected against in chronological aging and the direct targets of SIR2 in replicative lifespan are not *** it would be difficult to imagine how a gene that advantages 1 in 5 million yeast cells could have anticipated causes of aging in animals,overexpression of SIR2 homologs was tested in invertebrates for *** artifactual positive results were reported years before they were sorted out and because it was not known that SIR2 functions as a pro-aging gene in yeast chronological aging and in flies subject to amino acid deprivation,a global pursuit of longevity phenotypes was driven by a mixture of framing bias,confirmation bias,and *** articles that propagate these biases are so rampant that few investigators have considered how weak the case ever was for sirtuins as longevity *** that a few positive associations between sirtuins and longevity have been identified after thousands of person-years and billions of dollars of effort,we review the data and suggest rejection of the notions that sirtuins(i)have any specific connection to lifespan in animals and(ii)are primary mediators of the beneficial effects of NAD repletion.

关键词： sirtuins longevity model organism publication bias resveratrol nicotinamide adenine dinucleotide

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The skeleton gets a （reproductive） life

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Asian Journal of Andrology 2011年第5期13卷 651-652页

作者： charles M Allan David l Handelsman ANZAC Research Institute Concord Hospital Universityof Sydney Sydney NSW 2139 Australia

To most well-informed scientists who do not work on bone, the idea that bones determine anything other than your posture and location for the miseries of arthritis would come as quite a surprise. It would be like imagining that the walls of our home played something more than a passive role in the complexities of the lives conducted within. Yet something precisely as radical as that is what Karsenty and his colleagues boldly imagined,1 and then provocatively established in a series of studies over the past decade.20steocalcin （OCN） is a vitamin K- dependent peptide hormone secreted by the bone-formine osteoblasts.

关键词： reproductive David J Handelsman

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Strain engineering of electro-optic constants in ferroelectric materials

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npj Computational Materials 2019年第1期5卷 1092-1096页

作者： charles Paillard Sergei Prokhorenko Laurent Bellaiche Department of Physics and Institute for Nanoscience and Engineering University of ArkansasFayettevilleAR 72701USA

Electro-optic effects allow control of the ow of light using electric fields,and are of utmost importance for today’s information and communication technologies,such as TV displays and fiber *** search for large electro-optic constants in films is essential to the miniaturization and increased efficiency of electro-optic *** this work,we demonstrate that strain-engineering in PbTiO_(3) films allows to selectively choose which electro-optic constant to *** electro-optic constants larger than 100 pm V^(−1) are predicted,either by driving the softening of an optical phonon mode at a phase transition boundary under tensile strain,or by generating the equivalent of a negative pressure via compressive strain to obtain large piezoelectric *** particular,a r_(13) electro-optic coefficient twice as large as the one of the commonly used LiNbO_(3) electro-optic material is found here when growing PbTiO_(3) on the technologicallyimportant Si substrate.

关键词： softening constants ferroelectric

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Classifying Environmental Features From Local Observations of Emergent Swarm Behavior

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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 674-682页

作者： Megan Emmons Anthony AMaciejewski charles Anderson Edwin KPChong IEEE Department of Electrical and Computer Engineering Colorado State UniversityFort CollinsCO 80523 USA Department of Computer Science Colorado State UniversityFort CollinsCO 80523 USA

Robots in a swarm are programmed with individual behaviors but then interactions with the environment and other robots produce more complex, emergent swarm behaviors. One discriminating feature of the emergent behavior is the local distribution of robots in any given region. In this work, we show how local observations of the robot distribution can be correlated to the environment being explored and hence the location of openings or obstructions can be inferred. The correlation is achieved here with a simple, single-layer neural network that generates physically intuitive weights and provides a degree of robustness by allowing for variation in the environment and number of robots in the swarm. The robots are simulated assuming random motion with no communication, a minimalist model in robot sophistication, to explore the viability of cooperative sensing. We culminate our work with a demonstration of how the local distribution of robots in an unknown, office-like environment can be used to locate unobstructed exits.

关键词： Biologically inspired robotics environment exploration multi-agent systems swarm robotics

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