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Heterostructure and Q-factor engineering for low-threshold and persistent nanowire lasing

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Light(Science & Applications) 2020年第1期9卷 1609-1618页

作者： Stefan Skalsky Yunyan Zhang Juan Arturo Alanis HAruni Fonseka Ana m.Sanchez Huiyun Liu patrick Parkinson Department of Physics and Astronomy and The Photon Science Institute The University of ManchesterManchester M139PLUK Department of Electronic and Electrical Engineering University College LondonLondon WC1E 7JEUK Department of Physics University of WarwickCoventry CV47ALUK

Continuous room temperature nanowire lasing from silicon-integrated optoelectronic elements requires careful optimisation of both the lasing cavity Q-factor and population inversion *** apply time-gated optical interferometry to the lasing emission from high-quality GaAsP/GaAs quantum well nanowire laser structures,revealing high Q-factors of 1250±90 corresponding to end-facet reflectivities of R=0.73±*** using optimised direct-indirect band alignment in the active region,we demonstrate a well-refilling mechanism providing a quasifour-level system leading to multi-nanosecond lasing and record low room temperature lasing thresholds(~6μJ cm^(−2) pulse−1)for Ⅲ-Ⅴ nanowire *** findings demonstrate a highly promising new route towards continuously operating silicon-integrated nanolaser elements.

关键词： lasing alignment interferometry

Convex Variational Formulation with Smooth Coupling for multicomponent Signal Decomposition and Recovery

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Numerical mathematics(Theory,methods and Applications) 2009年第4期2卷 485-508页

作者： Luis m.Briceo-Arias patrick L.Combettes UPmC Universite Paris 06 Laboratoire Jacques-Louis Lions-UMR 7598 and Equipe Combinatoire et Optimisation-UMR 7090 UPmC Universite Paris 06 Laboratoire Jacques-Louis Lions-UMR 7598

A convex variational formulation is proposed to solve multicomponent signal processing problems in Hilbert *** cost function consists of a separable term, in which each component is modeled through its own potential,and of a coupling term, in which constraints on linear transformations of the components are penalized with smooth *** algorithm with guaranteed weak convergence to a solution to the problem is *** multicomponent signal decomposition and recovery applications are discussed.

关键词： Convex optimization denoising image restoration proximal algorithm signal decom-position signal recovery

A fine-scale assessment of the ecosystem service-disservice dichotomy in the context of urban ecosystems affected by alien plant invasions

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Forest Ecosystems 2019年第4期6卷 323-338页

作者： Luke J.Potgieter mirijam Gaertner patrick J.O’Farrell David m.Richardson Centre for Invasion Biology Department of Botany and ZoologyStellenbosch University

Background: Natural resources within and around urban landscapes are under increasing pressure from ongoing urbanisation, and management efforts aimed at ensuring the sustainable provision of ecosystem services(ES) are an important response. Given the limited resources available for assessing urban ES in many cities, practical approaches for integrating ES in decision-making process are ***: We apply remote sensing techniques(integrating LiDAR data with high-resolution multispectral imagery)and combined these with supplementary spatial data to develop a replicable approach for assessing the role of urban vegetation(including invasive alien plants) in providing ES and ecosystem disservices(EDS). We identify areas denoting potential management trade-offs based on the spatial distribution of ES and EDS using a local-scale case study in the city of Cape Town, South Africa. Situated within a global biodiversity hotspot, Cape Town must contend with widespread invasions of alien plants(especially trees and shrubs) along with complex socio-political challenges. This represents a useful system to examine the challenges in managing ES and EDS in the context of urban plant ***: Areas of high ES provision(for example carbon sequestration, shade and visual amenity) are characterized by the presence of large trees. However, many of these areas also result in numerous EDS due to invasions of alien trees and shrubs – particularly along rivers, in wetlands and along the urban edge where tall alien trees have established and spread into the natural vegetation(for example increased water consumption, increased fire risk and reduced soil quality). This suggests significant trade-offs regarding the management of species and the ES and EDS they ***: The approach applied here can be used to provide recommendations and to guide city planners and managers to fine-tune management interventions at local scales to maximise the provision of ES.

关键词： Biodiversity Biological invasions Ecosystem disservices Ecosystem services Remote sensing Trade-offs Tree invasions Urban plant invasions

Optimal Ternary Cubic Two-Weight Codes

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Chinese Journal of Electronics 2018年第4期27卷 734-738页

作者： SHI minjia HUANG Daitao SOL patrick Key Laboratory of Intelligent Computing & Signal Processing Ministry of EducationAnhui University School of mathematical Sciences Anhui University CNRS/LAGA University of Paris 8

We study trace codes with defining set L,a subgroup of the multiplicative group of an extension of degree m of a certain ring of order 27. These codes are abelian, and their ternary images are quasi-cyclic of coindex three(a.k.a. cubic codes). Their Lee weight distributions are computed by using Gauss sums. These codes have three nonzero weights when m is singly-even. When m is odd, under some hypothesises on the size of L, we obtain two new infinite families of two-weight codes which are optimal. Applications of the image codes to secret sharing schemes are also given.

关键词： Three-weight codes Two-weight codes Gauss sums Trace codes

Does the mcNeill Alexander model accurately predict maximum walking speed in novice and experienced race walkers？

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Journal of Sport and Health Science 2018年第3期7卷 372-377页

作者： Andrew J.Harrison patrick G.molloy Laura-Anne m.Furlong Department of Physical Education and Sport Sciences University of LimerickCastletroyLimerick V94 T9PXIreland School of Sport Exercise and Health Sciences Loughborough UniversityEpinalWayLoughboroughLeicestershire LEll 3TUUK

Background:mathematical models propose leg length as a limiting factor in determining the maximum walking *** study evaluated the effectiveness of a leg length-based model in predicting maximum walking velocity in an applied race walking situation,by comparing experienced and novice race walkers during conditions where strictly no flight time(FT)was permitted and in simulated competition conditions(i.e.,FTms).methods:Thirty-four participants(18 experienced and l6 novice race walkers)were recruited for this *** Optojump Next system(8 m)was used to determine walking velocity,step frequency,step length,ground contact time,and FT during race walking over a range of *** were made between novice and experienced participants in predicted maximum velocity and actual velocities achieved with no flight and velocities with FTmaximum velocity to predicted ***:In novices,no significant difference was found between predicted and maximum walking speeds without FT but there was a small 5.8%gain in maximum speed when FT≤40 *** experienced race walkers,there was a significant reduction in maximum walking speed compared with predicted maximum(pmaximum walking speed with FTmaximal walking velocity in novice walkers but not a good predictor of maximum walking speed in well-trained walkers who appear to have optimised their walking technique to make use of non-visible flight periods of less than 40 *** gain in velocity above predicted maximum may be a useful index of race walking proficiency.

关键词： Biomechanics Gait mathematical modelling Race walking Sports technique Technique development

Assessing the performance of different outcomes for tumor growth studies with animal models

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Animal models and Experimental medicine 2022年第3期5卷 248-257页

作者： Luke W.Patten patrick Blatchford matthew Strand Alexander m.Kaizer Department of Biostatistics and Informatics University of ColoradoAuroraColoradoUSA

The consistency of reporting results for patient-derived xenograft(PDX) studies is an area of concern. The PDX method commonly starts by implanting a derivative of a human tumor into a mouse, then comparing the tumor growth under different treatment conditions. Currently, a wide array of statistical methods(e.g., t-test, regression, chi-squared test) are used to analyze these data, which ultimately depend on the outcome chosen(e.g., tumor volume, relative growth, categorical growth). In this simulation study, we provide empirical evidence for the outcome selection process by comparing the performance of both commonly used outcomes and novel variations of common outcomes used in PDX studies. Data were simulated to mimic tumor growth under multiple scenarios, then each outcome of interest was evaluated for 10?000 iterations. Comparisons between different outcomes were made with respect to average bias, variance, type-1 error, and power. A total of 18 continuous, categorical, and time-to-event outcomes were evaluated, with ultimately 2 outcomes outperforming the others: final tumor volume and change in tumor volume from ***, the novel variations of the tumor growth inhibition index(TGII)— a commonly used outcome in PDX studies— was found to perform poorly in several scenarios with inflated type-1 error rates and a relatively large bias. Finally, all outcomes of interest were applied to a real-world dataset.

关键词： mouse model oncology outcome selection patient-derived xenograft(PDX) statistical analysis TGII translational science

Adopting novel ecosystems as suitable rehabilitation alternatives for former mine sites

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Ecological Processes 2013年第1期2卷 221-231页

作者： David Doley patrick Audet Centre for mined Land Rehabilitation Sustainable Minerals InstituteThe University of QueenslandBrisbane(St.Lucia)QLD 4072Australia

The nature and extent of environmental disturbance associated with mining commonly entails completely new and challenging combinations of climate,lithology and ***,the outcomes of ecological processes associated with the recovery or restoration of ecosystems cannot be predicted reliably from previously known associations between their physical and biological *** radically disturbed sites,we propose that it is not practicable to aim for the restoration of historical ***,hybrid(reversibly different)or novel(irreversibly different)ecosystems comprising new combinations of physical and biological components,including both native and non-native species,could provide levels of stability and functionality acceptable to all stakeholders and within feasible management *** propose that limiting physical conditions of the landscape can be identified and managed,and that alternative species combinations for introduction to these new landscapes may be considered with cautious optimism.

关键词： Natural ecological analogues Novel ecosystems mining Landscape suitability

Liquid vaporization under thermodynamic phase non-equilibrium condition at the gas-liquid interface

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Science China(Technological Sciences) 2020年第12期63卷 2649-2656页

作者： WANG XingJian LAFON patrick SUNDARAm Dilip YANG Vigor Department of mechanical and Civil Engineering Florida Institute of TechnologyMelbourneFlorida 32901USA Department of mechanical and Nuclear Engineering The Pennsylvania State UniversityUniversity ParkPA 16802USA School of Aerospace Engineering Georgia Institute of TechnologyAtlantaGA 30332USA

Liquid vaporization under thermodynamic phase non-equilibrium condition at the gas-liquid interface is investigated over a wide range of fluid state typical of many liquid-fueled energy conversion systems. The validity of the phase-equilibrium assumption commonly used in the existing study of liquid vaporization is examined using molecular dynamics theories. The interfacial mass flow rates on both sides of the liquid surface are compared to the net vaporization rate through an order-of-magnitude *** indicated that the phase-equilibrium assumption holds valid at relatively high pressures and low temperatures,and for droplets with relatively large initial diameters(for example,larger than 10 μm for vaporizing oxygen droplets in gaseous hydrogen in the pressure range from 10 atm to the oxygen critical state). Droplet vaporization under superheated conditions is also explored using classical binary homogeneous nucleation theory,in conjunction with a real-fluid equation of state. It is found that the bubble nucleation rate is very sensitive to changes in saturation ratio and pressure;it increases by several orders of magnitude when either the saturation ratio or the pressure is slightly increased. The kinetic limit of saturation ratio decreases with increasing pressure,leading to reduced difference between saturation and superheat conditions. As a result,the influence of nonequilibrium conditions on droplet vaporization is lower at a higher pressure.

关键词： liquid vaporization droplet vaporization superheated vaporization thermodynamic phase equilibrium thermodynamic phase non-equilibrium vapor nucleation

The Tomato Hybrid Proline-rich Protein regulates the abscission zone competence to respond to ethylene signals

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Horticulture Research 2018年第1期5卷 528-544页

作者： Srivignesh Sundaresan Sonia Philosoph-Hadas Chao ma Cai-Zhong Jiang Joseph Riov Raja mugasimangalam Betina kochanek Shoshana Salim michael SReid Shimon meir Department of Postharvest Science of Fresh Produce Agricultural Research Organization(ARO)The Volcani CenterRishon LeZiyonIsrael The Robert H.Smith Institute of Plant Sciences and Genetics in Agriculture The Robert H.Smith Faculty of AgricultureFood and EnvironmentThe Hebrew University of JerusalemRehovotIsrael Department of Plant Sciences University of CaliforniaDavisCAUSA Crops Pathology&Genetic Research Unit USDA-ARSDavisCAUSA Department of Bioinformatics QTLomics Technologies Pvt.LtdBangaloreIndia Department of Nano Science and Technology Tamil Nadu Agricultural UniversityCoimbatoreIndia Beijing Key Laboratory of Development and Quality Control of Ornamental Crops Department of Ornamental HorticultureChina Agricultural UniversityBeijingChina

The Tomato Hybrid Proline-rich Protein(THyPRP)gene was specifically expressed in the tomato(Solanum lycopersicum)flower abscission zone(FAZ),and its stable antisense silencing under the control of an abscission zone(AZ)-specific promoter,Tomato Abscission Polygalacturonase4,significantly inhibited tomato pedicel abscission following flower *** understanding the THyPRP role in regulating pedicel abscission,a transcriptomic analysis of the FAZ of THyPRP-silenced plants was performed,using a newly developed AZ-specific tomato microarray *** expression of THyPRP in the silenced plants was already observed before abscission induction,resulting in FAZ-specific altered gene expression of transcription factors,epigenetic modifiers,post-translational regulators,and *** data demonstrate that the effect of THyPRP silencing on pedicel abscission was not mediated by its effect on auxin balance,but by decreased ethylene biosynthesis and ***,THyPRP silencing revealed new players,which were demonstrated for the first time to be involved in regulating pedicel abscission *** include:gibberellin perception,Ca2+-Calmodulin signaling,Serpins and Small Ubiquitin-related modifier proteins involved in post-translational modifications,Synthaxin and SNARE-like proteins,which participate in exocytosis,a process necessary for cell *** changes,occurring in the silenced plants early after flower removal,inhibited and/or delayed the acquisition of the competence of the FAZ cells to respond to ethylene *** results suggest that THyPRP acts as a master regulator of flower abscission in tomato,predominantly by playing a role in the regulation of the FAZ cell competence to respond to ethylene signals.

关键词： Hybrid inhibited competence