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Dendroclimatic analysis of white pine (Pinus strobus L.)using long-term provenance test sites across eastern North America

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Forest Ecosystems 2018年第3期5卷 221-235页

作者： Sophan Chhin Ronald S.Zalesny Jr William C.parker John Brissette Division of Forestry and Natural Resources West Virginia University322 Percival HallPO Box 6125MorgantownWV26506USA USDA Forest Service Northern Research Station5985Highway KRhinelanderWI 54501USA Ontario Forest Research Institute 1235Queen St.ESault Ste.MarieON P6A 2E5Canada USDA Forest Service Northern Research Station271Mast RoadDurhamNH 03824USA

Background: The main objective of this study was to examine the climatic sensitivity of the radial growth response of 13 eastern white pine(Pinus strobus L.) provenances planted at seven test sites throughout the northern part of the species’ native distribution in eastern North ***: The test sites(i.e., Wabeno, Wisconsin, USA; Manistique, Michigan, USA; Pine River, Michigan, USA; Newaygo,Michigan, USA; Turkey Point, Ontario, Canada; Ganaraska, Ontario, Canada; and Orono, Maine, USA) examined in this study were part of a range-wide white pine provenance trial established in the early 1960 s in the eastern United States and Canada. Principal components analysis(PCA) was used to examine the main modes of variation [first(PC1) and second(PC2) principal component axes] in the standardized radial growth indices of the provenances at each test *** year scores for PC1 and PC2 were examined in relation to an array of test site climate variables using multiple regression analysis to examine the commonality of growth response across all provenances to the climate of each test site. Provenance loadings on PC1 and PC2 were correlated with geographic parameters(i.e., latitude, longitude,elevation) and a suite of biophysical parameters associated with provenance origin ***: The amount of variation in radial growth explained by PC1 and PC2 ranged from 43.4% to 89.6%. Dendroclimatic models revealed that white pine radial growth responses to climate were complex and differed among sites. The key dendroclimatic relationships observed included sensitivity to high temperature in winter and summer, cold temperature in the spring and fal(i.e., beginning and end of the growing season), summer moisture stress, potential sensitivity to storminduced damage in spring and fal, and both positive and negative effects of higher winter snowfal. Separation of the loadings of provenances on principal component axes was mainly associated with temperature-related bioclima

关键词： Adaptation Climate change Dendrochronology Seed source

Numerical Analysis of Tilted Cutting and F128 Brushes

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Computer Modeling in Engineering & Sciences 2019年第10期121卷 23-47页

作者： Libardo V.Vanegas-Useche Magd M.Abdel-Wahab Graham A.parker Facultad de Ingeniería Mecánica Universidad Tecnológica de PereiraLa JulitaPereira 660003Colombia Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityViet Nam Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 46B-9052 ZwijnaardeBelgium Faculty of Engineering and Physical Sciences University of Surrey.Guildford GU27XHUK.

Road sweeping is an essential service that has to be conducted for public health,as well as aesthetic *** many countries,sweeping vehicles are used for this *** usually comprise a gutter brush that sweeps the debris that is located in the road *** work studies the performance of two kinds of gutter brushes:a cutting brush and a flicking(F128)*** is carried out by means of a 3-D dynamic,nonlinear Finite Element(FE)brush model developed by the *** this model,inertia forces are applied to the bristle,and its clamped end is ***,the surface(road)is rotated,translated,and ***-road interaction is modelled as flexible-to-rigid *** particular,the aim of this article is to compare the performance of a conventional brush and a brush rotating at variable *** brushes normally work tilted,FE analyses are carried out for tilted cutting and F128 brushes,rotating at speeds that fluctuate at different *** is concluded that brush oscillations have a significant effect on bristle tip velocities and bristle-road ***,at certain frequencies,oscillations seem to improve sweeping performance of the F128 ***,they do not appear to improve significantly the performance of the cutting brush.

关键词： Gutter brushes cutting brush flicking brush FEM variable speed brushing

The Impact of Exchange Rate on Economic Growth in Central Africa

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The Impact of Exchange Rate on Economic Growth in Central Af...

作者： Sosso Ngando Nelson parker 浙江工商大学

学位级别：硕士

20世纪90年代以来,非洲国家经济逐步复苏,实现了快速增长。其中,中非经济增长相对显著。中非经济增长的主要原因可分为外部环境和内部因素的多个方面,包括战争和冲突的持续减少和政治稳定的显著增加。各国实施的宏观经济改革措施增强了... 详细信息

20世纪90年代以来,非洲国家经济逐步复苏,实现了快速增长。其中,中非经济增长相对显著。中非经济增长的主要原因可分为外部环境和内部因素的多个方面,包括战争和冲突的持续减少和政治稳定的显著增加。各国实施的宏观经济改革措施增强了中非经济的增长潜力,国际市场上商品成本和资本流入量的上升,有力地证明了中非国家的贸易和融资条件。由于不同的初始条件,中非国家在经济转型过程中面临的困难将大于其他国家。本文从重要经济体和货币市场两个维度出发,总结了影响中非国家经济的汇率波动途径,包括贸易规模效应、资本流动效应和货币稳定效应。利用2000-2016年中非主要经济体月度面板数据,采用TGARCH模型测算汇率波动性指标,采用PVAR模型实证检验汇率波动对中非经济的影响。研究发现,利率波动促进了资本流动,但它绝对不是国际贸易事件的附属因素。它在一定程度上加剧了货币市场的动荡,这不是中非经济事件的附庸,阻碍了中非经济的复苏。在此基础上,本文提出了相应的对策。

关键词：中非汇率经济增长

Determination of the Normal Contact Stiffness and Integration Time Step for the Finite Element Modeling of Bristle-Surface Interaction

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Computers, Materials & Continua 2018年第7期56卷 169-184页

作者： Libardo V.Vanegas-Useche Magd M.Abdel-Wahab Graham A.parker Facultad de Ingeniería Mecánica Universidad Tecnológica de Pereira.Pereira 660003Colombia Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 903Zwijnaarde B-9052Belgium Faculty of Engineering and Physical Sciences University of Surrey.GuildfordUK

In finite element modeling of impact,it is necessary to define appropriate values of the normal contact stiffness,Kn,and the Integration Time Step(ITS).Because impacts are usually of very short duration,very small ITSs are ***,the selection of a suitable value of Kn is a critical issue,as the impact behavior depends dramatically on this *** this work,a number of experimental tests and finite element analyses have been performed in order to obtain an appropriate value of Kn for the interaction between a bristle of a gutter brush for road sweeping and a concrete ***,a suitable ITS is *** experiments consist of releasing a steel bristle that is placed vertically at a certain distance from a concrete surface and tracking the ***,in the finite element analyses,a beam is modeled in free fall and impacting a surface;contact and target elements are attached to the beam and the surface,*** results of the experiments and the modeling are integrated through the principle of conservation of energy,the principle of linear impulse and momentum,and Newton’s second *** results demonstrate that,for the case studied,Kn and the impact time tend to be independent of the velocity just before impact and that Kn has a very large variation,as concrete is a composite material with a rough ***,the ratio between the largest height of the bristle after impact and the initial height tends to be constant.

关键词： Brush street sweeping finite element modeling contact mechanics

Drug clinical trials on high-grade gliomas: challenges and hopes

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Cancer Biology & Medicine 2023年第12期20卷 947-954页

作者： Mengqian Huang Shenglan Li parker Li Zhuang Kang Botao Zhang Wenbin Li Cancer Center Beijing Tiantan HospitalCapital Medical UniversityBeijing 100070China Clinical Medicine Shanghai Jiao Tong University School of MedicineShanghai 200025China

Gliomas are the most common group of malignant central nervous system tumors across all ages and have high *** to histopathologic criteria and molecular pathology,gliomas are classified as grades 1–***-grade gliomas(HGG),including the most aggressive subtype,glioblastoma(GBM),belong to grade 3 or *** a standard therapy comprising surgical resection,chemotherapy,and radiation is available,almost all patients with HGG experience recurrence within several months and a dismal prognosis1.

关键词： glioma chemotherapy pathology

The tumor suppressor RASSF1A is a novel effector of small G protein Rap1A

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Protein & Cell 2011年第3期2卷 237-249页

作者： Sunil K.Verma Trivadi S.Ganesan Uday Kishore Peter J.parker Department of Medical Oncology Medical Sciences DivisionThe University of OxfordOxford OX39DUUK Ovarian Cancer Group CRUK Molecular Oncology LaboratoriesWeatherall Institute of Molecular MedicineJohn Radcliffe HospitalHeadingtonOxford OX39DSUK Protein Phosphorylation Laboratory London Research InstituteCRUK Lincoln's Inn Fields Laboratories44 Lincoln's Inn FieldsLondon WC2A 3PXUK Kings College London The Division of Cancer StudiesSection of Cancer Cell Biology and Imaging2nd FloorNew Hunt's HouseGuy's HospitalSt Thomas StreetLondon SE11ULUK Current address:Center for Cellular and Molecular Biology Uppal RoadHyderabad 500007India Current address:Cancer Institute&Institute of Molecular Medicine Amrita Institute of Medical SciencesElamakkara P.O.KochiKerala 682026India Center for Infection Immunity and Disease MechanismsBiosciencesSchool of Health Sciences and Social CareBrunel UniversityUxbridge UB83PHWest LondonUK

Rap1A is a small G protein implicated in a spectrum of biological processes such as cell proliferation,adhesion,differentiation,and *** downstream effectors through which Rap1A mediates its diverse effects are largely *** we show that Rap1A,but not the related small G proteins Rap2 or Ras,binds the tumor suppressor Ras association domain family 1A(RASSF1A)in a manner that is regulated by phosphorylation of *** with Rap1A is shown to influence the effect of RASSF1A on microtubule behavior.

关键词： RASSF1A Rap1A microtubule vimentin protein-protein interaction

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生成式人工智能的未来

商学院 2024年第4期 14-14页

作者： Atin Gupta Geoffrey G.parker 麻省理工学院斯隆管理学院麻省理工学院

生成式人工智能的发展已经在数字世界中带来了巨大变革,它可以创建新颖且真实的内容,例如文本、图像、音乐、视频和代码。如今,它也正逐渐渗透到物理世界,为我们处理各种机器和机器人任务提供帮助。在牛津大学研究人员最近的一项研究中... 详细信息

生成式人工智能的发展已经在数字世界中带来了巨大变革,它可以创建新颖且真实的内容,例如文本、图像、音乐、视频和代码。如今,它也正逐渐渗透到物理世界,为我们处理各种机器和机器人任务提供帮助。在牛津大学研究人员最近的一项研究中,人工智能专家预测,未来十年内,高达40%的家务活将实现自动化。

关键词：人工智能牛津大学生成式机器人未来十年自动化巨大变革

PEPT study of particle motion for different riser exit geometries

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Particuology 2010年第6期8卷 623-630页

作者： Chian Wen Chan Anke Brems Shiva Mahmoudi Jan Baeyens Jonathan Seville David parker Thomas Leadbeater Joseph Gargiuli University of Warwick School of EngineeringCoventryCV4 7 ALUK Katholieke Universiteit Leuven Department of Chemical Engineeringde Croylaan463001LeuvenBelgium University of Birmingham School of Physics and AstronomyBirminghamB22 T15UK

Laboratory and industrial risers are equipped with exits of many different layouts, and numerous publications discuss the influence of riser exit geometry on local and overall solids hydrodynamics in the riser. The present paper reviews literature findings--mostly based upon indirect experimental techniques and often somewhat contradictory, Direct measurement of particle velocity and particle occupancy near and in the riser exit provide a better indication of the effect of riser exit geometry. Positron Emission Particle Tracking （PEPT） was used in this work for the first time to investigate the exit region of the riser, An abrupt or sharp exit causes particles to be knocked out of the gas flow, so forming a recirculation or reflux region in the upper part of the riser. This is much less pronounced with a curved or gradual exit.

关键词： CFB Riser Exit geometries Positron Emission Particle Tracking

High throughput materials research and development for lithium ion batteries

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Journal of Materiomics 2017年第3期3卷 202-208页

作者： parker Liu Bingkun Guo Tanglin An Hui Fang Genxiang Zhu Chris Jiang Xiaoping Jiang MTI Corporation 860 South 19th StreetRichmondCA 94804USA Shanghai University 99 Shangda RoadBaoshan DistrictShanghai 200444China Kejing Materials Technology Co.Ltd. 10 Kexueyuan RoadHefeiAnhui 230088China

Development of next generation batteries requires a breakthrough in *** one-by-one method,which is suitable for synthesizing large number of sing-composition material,is timeconsuming and *** throughput and combinatorial experimentation,is an effective method to synthesize and characterize huge amount of materials over a broader compositional region in a short time,which enables to greatly speed up the discovery and optimization of materials with lower *** this work,high throughput and combinatorial materials synthesis technologies for lithium ion battery research are discussed,and our efforts on developing such instrumentations are introduced.

关键词： High throughput Materials synthesis Lithium-ion battery