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Balanced and Unbalanced Components of moist Atmospheric Flows with Phase Changes

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Chinese Annals of mathematics,Series B 2019年第6期40卷 1005-1038页

作者： Alfredo N.WETZEL Leslie m.smith Samuel N.STECHmANN Jonathan E.mARTIN Department of mathematics University of Wisconsin-MadisonMadisonWI 53706USA Department of mathematics and Department of Engineering Physics University of Wisconsin-MadisonMadisonWI 53706USA Department of mathematics and Department of Atmospheric and Oceanic Sciences University of Wisconsin-MadisonMadisonWI 53706USA Department of Atmospheric and Oceanic Sciences University of Wisconsin-MadisonMadisonWI 53706USA

Atmospheric variables(temperature, velocity, etc.) are often decomposed into balanced and unbalanced components that represent low-frequency and high-frequency waves, respectively. Such decompositions can be defined, for instance, in terms of eigenmodes of a linear operator. Traditionally these decompositions ignore phase changes of water since phase changes create a piecewise-linear operator that differs in different phases(cloudy versus non-cloudy). Here we investigate the following question: How can a balanced–unbalanced decomposition be performed in the presence of phase changes? A method is described here motivated by the case of small Froude and Rossby numbers,in which case the asymptotic limit yields precipitating quasi-geostrophic equations with phase changes. Facilitated by its zero-frequency eigenvalue, the balanced component can be found by potential vorticity(PV) inversion, by solving an elliptic partial differential equation(PDE), which includes Heaviside discontinuities due to phase changes. The method is also compared with two simpler methods: one which neglects phase changes, and one which simply treats the raw pressure data as a streamfunction. Tests are shown for both synthetic, idealized data and data from Weather Research and Forecasting(WRF) model simulations. In comparisons, the phase-change method and no-phase-change method produce substantial differences within cloudy regions, of approximately 5K in potential temperature, due to the presence of clouds and phase changes in the data. A theoretical justification is also derived in the form of a elliptic PDE for the differences in the two streamfunctions.

关键词： Potential vorticity inversion moist atmospheric dynamics Slow-fast systems Balanced-unbalanced decomposition Elliptic partial differential equations

Effects of single-tree selection harvesting on hymenopteran and saproxylic insect assemblages in the canopy and understory of northern temperate forests

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Journal of Forestry Research 2012年第2期23卷 275-284页

作者： sandy m. smith Nurul Islam m. Isabel Bellocq Faculty of Forestry University of Toronto 33 Willcocks St. Toronto Ontario M5S 3B3 Canada Departamento de Ecología Genética y Evolución FCEN Universidad de Buenos Aires CONICET. Ciudad Universitaria Pab 2 Piso 4 Buenos Aires 1426 Argentina

Insects respond to changes in microhabitat caused by canopy disturbance, and thus can be used to examine the ecological impacts of harvesting. Single-tree selection harvesting is the most common silvicultural system used to emulate local small-scale natural disturbance and maintain uneven-aged forest structure in temperate forests. Here, we test for differences in richness, abundance, and composition of hymenopteran and saproxylic insect assemblages at four different taxon levels （selected insect orders; and all hymenopteran families, and braconid subfamilies and morphospecies） between the canopy and understory of unharvested and single-tree selection harvested sites in a northern temperate forest from central Canada. Harvesting had no effect on insect assemblage richness, composition or abundance at the three highest taxon levels （order, family and subfamily）. Similarly, richness and abundance at the lowest-taxon level （braconid morphospecies） were similar, although composition differed slightly between unharvested and harvested stands. Insect assemblages were vertically stratified, with generally higher abundance （for Diptera, Hymenoptera, some hymenopteran families and braconid subfamilies） and richness （for braconid morphospecies） in the understory than the canopy. In particular, composition of the braconid morphospecies assemblage showed relatively low similarity between the understory and canopy. Single-tree selection harvesting appears to influence wood-associated insect taxa only subtly through small changes in community composition at the lowest taxon level, and thus is recommended as a conservative approach for managing these northern temperate forests.

关键词： selection harvesting insect communities canopy insects Jack pine forests forest management high-taxon level insect conserva-tion

Acetylation as a mechanism that regulates axonal regeneration

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Neural Regeneration Research 2015年第7期10卷 1034-1036页

作者： Shen Lin George m.smith Shriners Hospitals for Pediatric Research Center Department of Neuroscience Temple University

The capacity for adult axons to regenerate after injury is diminished compared with developing *** the case of central nervous system（CNS）axons,injury causes a total failure to *** failure is due to both the intrins... 详细信息

关键词： gene HDAC Acetylation as a mechanism that regulates axonal regeneration

JIU GONG SHAN-FATHER OF TEA

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湖北科技学院学报 1993年第1期24卷 67-69页

作者： Nicholas m.smith

By the Qing Dynasty^1 present day Xianning Prefecture was well established as a producerof tea. and for much of that period dealt on the international markets. The rise of thePrefecfure’s tea empires was speedy, but histories of the tea towns leave unanswered thequestion where did all the tea come from? This article postulates that the prefecture’s tea originatedand was first cultivated in an area known as Jiu Gong Shan^2 as early as the Jin Dy-

关键词： cultivated leave Dynasty displayed valuable painting eaves throughout Canton largely

Does variable stand structure associated with multi-cohort forests support diversity of ground beetle (Coleoptera, Carabidae) communities in the central Nearctic boreal forest？

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Journal of Forestry Research 2016年第5期27卷 1191-1202页

作者： Erica P. Barkley Jay R. malcolm sandy m. smith m. Isabel Bellocq Faculty of Forestry University of Toronto 33 Willcocks Street Toronto ON M5S 3B3 Canada Departamento de Ecología Genética y Evolución IEGEBA(CONICET-UBA) Facultad de Ciencias Exactas y NaturalesUniversidad de Buenos Aires Buenos Aires Argentina

multi-cohort management （mCm） that retains a range of stand structures （age and size class） has been proposed to emulate natural disturbance and improve management in the Nearctic boreal forest. Although mCm forests contain both single- and multi-aged stands of mixed tree sizes, little is known about how variable stand structure affects associated fauna and biodiversity. Here, we examine the relationship between ground beetle （Coleoptera, Carabidae） communities and stand characteristics across a range of forest structure （=cohort classes）. Given that mCm classes are defined by the distribution of their tree-stem diameters, we ask whether parameters associated with these distributions （Weibull） could explain observed variation in carabid communities, and if so, how this compares to traditional habitat variables such as stand age, foliage complexity or volume of downed woody debris. We sampled carabids using weekly pitfall collections and compared these with structural habitat variables across a range of cohort classes （stand structure and age since disturbance） in 18 sites of upland mixed boreal forests from central Canada. Results showed that richness and diversity of carabid communities were similar among cohort classes. Weibull parameters from the diameter distribution of all stems were the strongest predictors of variation in carabid communities among sites, but vertical foliage complexity, understory thickness, and percentage of deciduous composition were also significant. The abundance of several carabid forest specialists was strongly correlated with tree canopy height, the presence of large trees, and high vertical foliage complexity. Our results demonstrate that variable forest structure, as expected under mCm, may be useful in retaining the natural range of ground beetle species across the central Nearctic boreal forest.

关键词： Biodiversity conservation Boreal forest Carabidae Forest structure Ground beetles multi-cohortmanagement Tree diameter distribution

Water balloon-induced orbital fracture in an aviator

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military medical Research 2020年第2期7卷 245-248页

作者： Timothy E.Holland David m.smith Guy N.Gibson Jared G.Brinkerhoff Flight and Operational medical Clinic 78th Medical Group655 Seventh StreetRobins Air Force BaseRobinsGA 31098USA Department of Radiology Ehrling Bergquist Clinic2501 Capehart RdOffutt AFBNEOffutt 68113-2160USA Flight and Operational medical Clinic 5th Medical Group194 Missilie AveMinot AFBNDMinot 58705USA

Background:Orbital fractures are common injuries found in facial *** etiologies of orbital fractures include motor vehicle collisions and *** report the case of a 32-year-old male who suffered an orbital fracture from a water ***,we describe the aeromedical complications that may result from this ***,we attempt to answer the question of when a patient may return to flying after sustaining such an injury through review of the *** presentation:A 32-year-old male pilot with the United States Air Force was at an outdoor event with his unit when he was struck with a water balloon launched from a sling shot into his left *** afterwards,he had an onset of subcutaneous emphysema and was escorted to a nearby Emergency *** tomography identified an orbital fracture with associated orbital and subcutaneous *** patient was evaluated by a plastic surgeon and was determined not to be a surgical *** weeks later,he returned to flying ***:Water balloons are thought to be safe and harmless ***,when coupled with sling shots,water balloons can become formidable projectiles capable of significant orbital injury including orbital *** injuries are concerning to aviators,as the most common sites for fractures of the orbit are the thin ethmoid and maxillary bones adjacent to the *** altitude,gases in the sinuses may expand and enter the orbit through these fractures,which may suddenly incapacitate the *** is important for flight surgeons to identify and assess these individuals to determine suitability for flying.

关键词： Boyle’s law Orbital emphysema Facial fracture

Tailoring spin mixtures by ion-enhanced maxwell magnetic coupling in colortunable organic electroluminescent devices

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Light(Science & Applications) 2018年第1期7卷 629-640页

作者： Junwei Xu Yue Cui Gregory m.smith Peiyun Li Chaochao Dun Linqi Shao Yang Guo Hongzhi Wang Yonghua Chen David L.Carroll Center for Nanotechnology and molecular materials Wake Forest UniversityWinston-SalemNC 27109USA Department of Physics Wake Forest UniversityWinston-SalemNC 27106USA Key Laboratory of Luminescence and Optical Information(ministry of Education) Institute of Optoelectronics TechnologyBeijing Jiaotong University100044 BeijingP.R.China Department of Electro-Optics School of EngineeringUniversity of DaytonDaytonOH 45469USA Department of mathematics Wake Forest UniversityWinston-SalemNC 27106USA State Key Laboratory for modification of Chemical Fibers and Polymer materials 201620 ShanghaiP.R.China College of materials Science and Engineering Donghua University201620 Shanghai P.R.China Institute of Advanced materials Nanjing Tech University211816 NanjingJiangsuP.R.China Department of Physics and Astronomy College of CharlestonCharlestonSC 29424USA

In this work,we show that the spin dynamics of excitons can be dramatically altered by maxwell magnetic field coupling,together with an ion-enhanced,low-internal-splitting-energy organic semiconducting *** employing a unique,alternating current(AC)-driven organic electroluminescent(OEL)device architecture that optimizes this magnetic field coupling,almost complete control over the singlet-to-triplet ratio(from fluorescent to phosphorescent emission in a single device)is *** attribute this spin population control to magnetically sensitive polaron–spin pair intersystem crossings(ISCs)that can be directly manipulated through external driving *** an illustration of the utility of this approach to spin-tailoring,we demonstrate a simple hybrid(double-layer)fluorescence–phosphorescence(F–P)device using a polyfluorene-based emitter with a strong external Zeeman effect and ion-induced long carrier *** control over de-excitation pathways is achieved by controlling the device-driving frequency,resulting in complete emission blue–red color *** photoluminescence(PL)spectroscopy directly confirms that this color control derives from the magnetic manipulation of the singlet-totriplet *** results may pave the way to far more exotic organic devices with magnetic-field-coupled organic systems that are poised to usher in an era of dynamic spintronics at room temperature.

关键词： temperature. coupling maxwell

Reactive astrocyte scar and axon regeneration:suppressor or facilitator?

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Neural Regeneration Research 2016年第7期11卷 1050-1051页

作者： Yosuke Ohtake George m.smith Shuxin Li Shriners Hospitals Pediatric Research Center Department of Anatomy and Cell BiologyDepartment of NeuroscienceLewis Katz School of Medicine at Temple University

Several major factors are known to contribute to CNS axon regenerative failure after injury, including reduced intrinsic growth capacity of developed neurons and extrinsic factors mediating axon outgrowth. For the latter, a non-permissive environment around the lesion and the lack of sufficient neurotrophic support within the adult CNS play important roles （Silver et al., 2015）. In addition to generation of various inhibitory substrates by oligodendrocytes, fibrotic tissues, inflammatory cells and other cell types, reactive astrocytes surrounding lesions are thought to highly suppress regeneration of injured CNS axons （Silver and miller, 2004; Ohtake and Li, 2014）. A great number of studies suggest that reactive astrocytic scars form one of the major barriers preventing axon regeneration after CNS iniuries, including spinal cord injury （SCI）. However, reactive astrocytes were reported to provide a beneficial role by reducing infiltrating immunoreactive cells into adjacent domains, protecting bordering neural tissue from damage and generating numerous supportive extracellular matrix （ECm） components to promote cell survival and growth （Bush et al., 1999）. Previ- ous data showed that ablation of reactive astrocytes increased inflammation and secondary tissue damage, prevented blood- brain barrier formation and increased local neurite growth. Interestingly, a recent study by Anderson et al （2016） provides evidence that reactive astrocytes around the lesioned spinal cord support axon regeneration after SCI, rather than block regrowth （Anderson et al., 2016）.

关键词： astrocyte regeneration suppressor neurotrophic extrinsic latter intrinsic glial injured sensory

Exploring the band structure of Wurtzite InAs nanowires using photocurrent spectroscopy

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Nano Research 2020年第6期13卷 1586-1591页

作者： Seyyedesadaf Pournia Samuel Linser Giriraj Jnawali Howard E.Jackson Leigh m.smith Amira Ameruddin Philippe Caroff Jennifer Wong-Leung Hark Hoe Tan Chennupati Jagadish Hannah J.Joyce Department of Physics University of CincinnatiCincinnatiOH45221-0011USA Department of Electronic materials Engineering Research School of PhysicsThe Australian National UniversityCanberraACT2601Australia Department of Engineering University of Cambridge9 JJ Thomson AvenueCambridgeCB30FAUK

Nano Research volume We use polarized photocurrent spectroscopy in a nanowire device to investigate the band structure of hexagonal Wurtzite *** of optical transitions between four valence bands and two conduction bands are observed which are consistent with the symmetries expected from group *** ground state transition energy identified from photocurrent spectra is seen to be consistent with photoluminescence emitted from a cluster of nanowires from the same growth *** the energies of the observed bands we determine the spin orbit and crystal field energies in Wurtzite *** information is vital to the development of crystal phase engineering of this important III-V semiconductor.

关键词： nanowires Wurtzite InAs photocurrent measurement optical selection rules energy band structure