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International Journal of Digital Earth 2019年第5期12卷 544-565页

作者： Ignacio San-Miguel david w.Andison Nicholas C.Coops Integrated Remote Sensing Studio Department of Forest Resources ManagementUniversity of British ColumbiaVancouverBCCanada Bandaloop Landscape-Ecosystem Services North VancouverBCCanada

Free and open access to the Landsat archive has enabled the detection and delineation of an unprecedented number of fire events across the *** the availability and potential of these data,few studies have analysed residual vegetation patterns and/or partial mortality of fire across the Canadian boreal forest,and those available,are either incomplete or ***,they all differ in the methods and spatial language,which makes it difficult for managers to interpret fire patterns over large *** is an urgent need for methods to help unify fire pattern observations across the Canadian boreal *** study explores the capacity of the Landsat data archive when coupled with a recently developed fire mapping approach and a robust spatial language to characterize and compare tree mortality patterns across the boreal plains ecozone,*** 507 fires 2.5 Mha mapped,this study represents the most comprehensive analysis of mortality patterns for study *** from this demonstration generated an accurate characterization of the fire patterns the various ecoregions based on seven key fire *** comparison between ecoregions revealed differences in the amount of residual vegetation,which in turn suggested various climate,topography and/or vegetation ecosystem drivers.

关键词： Fire emulation historical range of variability landscape metrics fire patterns disturbance-based management

Investigation of role of cartilage surface polymer brush border in lubrication of biological joints

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Friction 2022年第1期10卷 110-127页

作者： JinJing LIAO david w.SMITH Saeed MIRAMINI Bruce S.GARDINER Lihai ZHANG Department of Infrastructure Engineering.The University of Melbourne.Victoria 3010 Australia Faculty of Engineering and Mathematical Sciences The University of Western AustraliaWA 6009Australia College of Science Health.Engineering and Education.Murdoch UniversityWA 6150Australia

Although experimental evidence has suggested that the polymer brush border(PBB)on the cartilage surface is important in regulating fluid permeability in the contact gap,the current theoretical understanding of joint lubrication is still *** address this research gap,a multiscale cartilage contact model that includes PBB,in particular its effect on the fluid permeability of the contact gap,is developed in this *** modeling is employed to estimate the permeability of the contact *** permeability is classified into two categories:For a gap size>1μm,the flow resistance is assumed to be dominated by the cartilage roughness;for gap sizew resistance is assumed to be dominated by the surface polymers extending beyond the collagen network of the articular *** gap sizes of less than 1μm,the gap permeability decreases exponentially with increasing aggrecan concentration,whereas the aggrecan concentration varies inversely with the gap ***,the gap permeability is employed in a macroscale cartilage contact model,in which both the contact gap space and articular cartilage are modeled as two interacting poroelastic *** fluid exchange between these two media is achieved by imposing pressure and normal flux continuity boundary *** model results suggest that PBB can substantially enhance cartilage lubrication by increasing the gap fluid load support(e.g.,by 26 times after a 20-min indentation compared with the test model without a PBB).Additionally,the fluid flow resistance of PBB sustains the cartilage interstitial fluid pressure for a relatively long period,and hence reduces the vertical deformation of the ***,it can be inferred that a reduction in the PBB thickness impairs cartilage lubrication ability.

关键词： assumed polymer hence

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Phase field modeling with large driving forces

作者： (英)david w. Ferguson

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npj Computational Materials 2023年第1期9卷 623-631页

作者： Jin Zhang Alexander F.Chadwick david L.Chopp Peter w.Voorhees Department of Materials Science and Engineering Northwestern UniversityEvanstonIL 60208USA Department of Engineering Sciences and Applied Mathematics Northwestern UniversityEvanstonIL 60208USA

There is growing interest in applying phase field methods as quantitative tools in materials discovery and ***,large driving forces,common in many materials systems,lead to unstable phase field profiles,thus requiring fine spatial and temporal *** demands more computational resources,limits the ability to simulate systems with a suitable size,and deteriorates the capability of quantitative ***,we develop a strategy to map the driving force to a constant perpendicular to the *** with the third-order interpolation function,we find a stable phase field profile that is independent of the magnitude of the driving *** power of this approach is illustrated using three *** demonstrate that by using the driving force extension method,it is possible to employ a grid size orders of magnitude larger than traditional *** approach is general and should apply to many other phase field models.

关键词： forces interpolation apply

PRISMS-PF:A general framework for phase-field modeling with a matrix-free finite element method

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npj Computational Materials 2020年第1期6卷 1421-1432页

作者： Stephen Dewitt Shiva Rudraraju david Montiel w.Beck Andrews Katsuyo Thornton University of Michigan Department of Materials Science and Engineering2300 Hayward St.Ann ArborMI 48109USA University of Michigan Department of Mechanical Engineering2350 Hayward St.Ann ArborMI 48109USA University of wisconsin MadisonWI 53706USA

A new phase-field modeling framework with an emphasis on performance,flexibility,and ease of use is *** among the strategies employed to fulfill these objectives are the use of a matrix-free finite element method and a modular,application-centric code *** approach is implemented in the new open-source PRISMS-PF *** performance is enabled by the combination of a matrix-free variant of the finite element method with adaptive mesh refinement,explicit time integration,and multilevel *** testing with a particle growth problem shows PRISMS-PF with adaptive mesh refinement and higher-order elements to be up to 12 times faster than a finite difference code employing a second-order-accurate spatial discretization and first-order-accurate explicit time integration.

关键词： structure finite element

Convergence of ADMM for multi-block nonconvex separable optimization models

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Frontiers of Mathematics in China 2017年第5期12卷 1139-1162页

作者： Ke GUO Deren HAN david Z. w. wANG Tingting wU School of Mathematical Sciences and Key Laboratory for NSLSCS of Jiangsu Province Nanjing Normal University Nanjing 210023 China School of Civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798 Singapore School of Science Nanjing University of Posts and Telecommunications Nanjing 210023China

For solving minimization problems whose objective function is the sum of two functions without coupled variables and the constrained function is linear, the alternating direction method of multipliers （ADMM） has exhibited its efficiency and its convergence is well understood. when either the involved number of separable functions is more than two, or there is a nonconvex function~ ADMM or its direct extended version may not converge. In this paper, we consider the multi-block *** optimization problems with linear constraints and absence of convexity of the involved component functions. Under the assumption that the associated function satisfies the Kurdyka- Lojasiewicz inequality, we prove that any cluster point of the iterative sequence generated by ADMM is a critical point, under the mild condition that the penalty parameter is sufficiently large. we also present some sufficient conditions guaranteeing the sublinear and linear rate of convergence of the algorithm.

关键词： Nonconvex optimization separable structure alternating directionmethod of rnultip!iers (.ADMM) Kurdyka-Lojasiewicz inequality

Channel capacity investigation of a linear massive MIMO system using spherical wave model in LOS scenarios

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Science China(Information Sciences) 2016年第2期59卷 45-59页

作者： Liu LIU david w.MATOLAK Cheng TAO Yongzhi LI Bo AI Houjin CHEN Institute of Broadband wireless Mobile Communications Beijing Jiaotong University Department of Electrical Engineering University of South Carolina National Mobile Communications Research Laboratory Southeast University

Massive multiple-input multiple-output(MIMO) is a key technology for the 5th generation(5G)of wireless communication systems. The traditional plane wave channel model(PwM) is often not suitable for the large antenna structure, and in certain cases should be replaced by the more accurate spherical wave model(SwM). By using the spherical wave characterization method, this paper investigates the channel capacity performance of a linear massive MIMO system in line-of-sight(LOS) scenarios. Two types of access settings, the point to point(PTP) system and multi-user(MU) system, are considered. In the PTP setting, a geometrical optimization is performed to obtain configurations that are able to generate a full rank channel matrix for a linear massive MIMO system, which yields full spatial diversity even in LOS scenarios. Compared with the approximate and commonly applied rank-1 PwM, this is very useful for fixed wireless access and radio relay systems requiring high throughput. For the MU case, we compare the eigenvalue distributions of the LOS channels using the plane wave and spherical wave characterization method, and sum rate results are obtained by Monte Carlo simulations. The results show that MU systems using the more realistic and accurate SwM can achieve a higher sum rate than results from the PwM. This is beneficial and informative when designing massive MIMO wireless networks.

关键词： massive MIMO channel model plane wave model spherical wave model channel capacity

Saluenolide A,A Novel Eremophilanolide from Senecio saluenensis

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Chinese Chemical Letters 2002年第4期13卷 333-334页

作者： Yu ZHAO Peng wANG Simon PARSONS david w.H. RANKIN DepartmentofNaturalDrugResearch CollegeofPharmaceuticalSciencesZhejiangUniversityHangzhou310031

From Senecio saluenensis, a novel eremophilanolide Saluenolide A was isolated. Its structure was elucidated by 2D-NMR technique and X-ray diffraction.

关键词： Sesquiterpene eremophilanolide Senecio X-ray cytotoxicity.

Effect of stripe rust on the yield response of wheat to nitrogen

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The Crop Journal 2014年第4期2卷 201-206页

作者： Rakhesh Devadas Steven Simpfendorfer david Backhouse david w.Lamb Climate Change Cluster (C3) Faculty of Sciences University of Technology Sydney Australia Precision Agriculture Research Group University of New England Armidale NSW 2351 Australia NSw Department of Primary Industries Tamworth NSW 2340 Australia School of Environmental and Rural Science University of New England Armidale NSW 2351 Australia Cooperative Research Centre for Spatial Information P.O. Box 672 Carlton South VIC 3053 Australia

Nitrogen(N) is the most important fertiliser element determining the productivity of wheat.N nutrition is known to affect the level of stripe rust infection, with higher N associated with increased disease severity. Stripe rust, caused by Puccinia striiformis f. sp. tritici, is a major yield-limiting disease of wheat in Australia. This paper describes experiments designed to investigate the agronomic response to the interaction of various levels of N application and stripe rust severity in wheat varieties differing in response. Experimental plots were established in crop seasons 2006 and 2007 on the Liverpool Plains of northern NSw, ***, biomass, grain protein content(GPC) and harvest index(HI) data were *** rates of N increased the severity of stripe rust during grain filling. N application also increased yield and GPC in all varieties in both years. Stripe rust reduced the yield of the rust-susceptible wheat varieties, and GPC and proportion of added N recovered in the grain were also reduced in one year but not the other. It was evident from our experiment that stripe rust caused yield loss accompanied by either no change or reduction in GPC, indicating that the total amount of N entering the grain was reduced by stripe rust. The effects of stripe rust on N yield are most likely associated with reduced uptake of N during grain filling.

关键词： Puccinia striiformis Yield Grain protein Nitrogen deficiency

Treating amyotrophic lateral sclerosis with allogeneic Schwann cell-derived exosomal vesicles: a case report

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Neural Regeneration Research 2025年第4期20卷 1207-1216页

作者： Pascal J.Goldschmidt-Clermont Aisha Khan George Jimsheleishvili Patricia Graham Adriana Brooks Risset Silvera Alexander J.P.Goldschmidt Damien D.Pearse w.Dalton Dietrich Allan D.Levi James D.Guest Miller School of Medicine University of MiamiMiamiFLUSA Stem Cell Institute Miller School of MedicineUniversity of MiamiMiamiFLUSA The Miami Project to Cure Paralysis Miller School of MedicineUniversity of MiamiMiamiFLUSA Alzady International LLC MiamiFLUSA Neurological Surgery Miller School of MedicineUniversity of MiamiMiamiFLUSA

Schwann cells are essential for the maintenance and function of motor neurons,axonal networks,and the neuromuscular *** amyotrophic lateral sclerosis,where motor neuron function is progressively lost,Schwann cell function may also be ***,important signaling and potential trophic activities of Schwann cell-derived exosomal vesicles have been *** case report describes the treatment of a patient with advanced amyotrophic lateral sclerosis using serial intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles,marking,to our knowledge,the first instance of such *** 81-year-old male patient presented with a 1.5-year history of rapidly progressive amyotrophic lateral *** initial diagnosis,the patient underwent a combination of generic riluzole,sodium phenylbutyrate for the treatment of amyotrophic lateral sclerosis,and *** patient volunteered to participate in an FDA-approved single-patient expanded access treatment and received weekly intravenous infusions of allogeneic Schwann cell-derived exosomal vesicles to potentially restore impaired Schwann cell and motor neuron *** confirmed that cultured Schwann cells obtained from the amyotrophic lateral sclerosis patient via sural nerve biopsy appeared impaired(senescent)and that exposure of the patient’s Schwann cells to allogeneic Schwann cell-derived exosomal vesicles,cultured expanded from a cadaver donor improved their growth capacity in *** a period of observation lasting 10 weeks,during which amyotrophic lateral sclerosis Functional Rating Scale-Revised and pulmonary function were regularly monitored,the patient received weekly consecutive infusions of 1.54×1012(×2),and then consecutive infusions of 7.5×1012(×6)allogeneic Schwann cell-derived exosomal vesicles diluted in 40 mL of Dulbecco’s phosphate-buffered *** of the infusions were associated with adverse events such as infusion reactions(allergic or otherwise)or

关键词： allogeneic amyotrophic lateral sclerosis exosomes infusion neuromuscular junction Schwann cell