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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

Genetic and phenological variation of tocochromanol(vitamin E)content in wild(Daucus carota ***)and domesticated carrot(*** ***)

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Horticulture Research 2014年第1期1卷 221-226页

作者： Claire H Luby Hiroshi A Maeda Irwin L Goldman Department of Horticulture University of Wisconsin-MadisonMadisonWI 53706USA Department of Botany University of Wisconsin-MadisonMadisonWI 53706USA

Carrot roots(Daucus carota ***)produce tocochromanol compounds,collectively known as vitamin ***,little is known about their types and *** we determined the range and variation in types and amounts of tocochromanols in a variety of cultivated carrot accessions throughout carrot postharvest storage and reproductive stages and in wild-type roots(Daucus carota ***).Of eight possible tocochromanol compounds,we detected and quantified α-,and the combined peak for β-and γ-forms of tocopherols and *** variation in amounts of tocochromanol compounds was observed across accessions and over *** increases in a-tocopherol were noted during both reproductive growth and the postharvest *** variation of tocochromanols in carrot root tissue provides useful information for future research seeking to understand the role of these compounds in carrot root tissue or to breed varieties with increased levels of these compounds.

关键词： sativa cultivated vitamin

Excitation and detection of coherent sub-terahertz magnons in ferromagnetic and antiferromagnetic heterostructures

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npj Computational Materials 2022年第1期8卷 1606-1614页

作者： Shihao Zhuang Jia-Mian Hu Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI53706USA

Excitation of coherent high-frequency magnons(quanta of spin waves)is critical to the development of high-speed magnonic *** we computationally demonstrate the excitation of coherent sub-terahertz(THz)magnons in ferromagnetic(FM)and antiferromagnetic(AFM)thin films by a photoinduced picosecond acoustic *** calculations are also performed to reveal the magnon excitation *** spin pumping and spin-charge conversion,these magnons can inject sub-THz charge current into an adjacent heavy-metal film which in turn emits electromagnetic(EM)*** a dynamical phase-field model that considers the coupled dynamics of acoustic waves,spin waves,and EM waves,we show that the emitted EM wave retains the spectral information of all the sub-THz magnon modes and has a sufficiently large amplitude for near-field *** predictions indicate that the excitation and detection of sub-THz magnons can be realized in rationally designed FM or AFM thin-film heterostructures via ultrafast optical-pump THz-emission-probe spectroscopy.

关键词： pumping pump coherent

Electron Tomography in Plant Cell Biology

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Journal of Integrative Plant Biology 2007年第8期49卷 1091-1099页

作者： ThomasJ.Haas MarisaS.Otegui Department of Botany University of Wisconsin-MadisonMadisonWI 53706USA

This review focuses on the contribution of electron tomography-based techniques to our understanding of cellular processes in plant cells. Electron microscopy techniques have evolved to provide better three-dimensional resolution and improved preservation of the subcellular components. In particular, the combination of cryofixation/freeze substitution and electron tomography have allowed plant cell biologists to image organelles and macromolecular complexes in their native cellular context with unprecedented three-dimensional resolution （4-7 nm）. Until now, electron tomography has been applied in plant cell biology for the study of cytokinesis, Golgi structure and trafficking, formation of plant endosome/prevacuolar compartments, and organization of photosynthetic membranes. We discuss in this review the new insights that these tomographic studies have brought to the plant biology field.

关键词： cell structure electron tomography high-pressure freezing/freeze substitution.

Nanosecond mid-infrared pulse generation via modulated thermal emissivity

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Light(Science & Applications) 2019年第1期8卷 724-731页

作者： Yuzhe Xiao Nicholas A.Charipar Jad Salman Alberto Pique Mikhail A.Kats Department of Electrical and Computer Engineering University of Wisconsin-MadisonMadisonWI 53706USA Naval Research Laboratory 4555 Overlook Ave.SWWashingtonDC 20375USA Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI 53706USA Department of Physics University of Wisconsin-MadisonMadisonWI 53706USA

We demonstrate the generation of nanosecond mid-infrared pulses via fast modulation of thermal emissivity enabled by the absorption of visible pump pulses in unpatterned silicon and gallium *** free-carrier dynamics in these materials result in nanosecond-scale modulation of thermal emissivity,which leads to nanosecond pulsed thermal *** our knowledge,the nanosecond thermal-emissivity modulation in this work is three orders of magnitude faster than what has been previously *** also indirectly observed subnanosecond thermal pulses from hot carriers in *** experiments are well described by our multiphysics *** method of converting visible pulses into the mid infrared using modulated emissivity obeys different scaling laws and can have significant wavelength tunability compared to approaches based on conventional nonlinearities.

关键词： pump emissivity thermal

A REDUCED ORDER SCHWARZ METHOD FOR NONLINEAR MULTISCALE ELLIPTIC EQUATIONS BASED ON TWO-LAYER NEURAL NETWORKS

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Journal of Computational Mathematics 2024年第2期42卷 570-596页

作者： Shi Chen Zhiyan Ding Qin Li Stephen J.Wright Mathematics Department University of Wisconsin-MadisonMadisonWI 53706USA Department of Mathematics University of California-BerkeleyBerkeley CA 94720USA Mathematics Department and Discovery Institute University of Wisconsin-Madison MadisonWI 53706USA Computer Sciences Department University of WisconsinMadisonWI 53706USA

Neural networks are powerful tools for approximating high dimensional data that have been used in many contexts,including solution of partial differential equations(PDEs).We describe a solver for multiscale fully nonlinear elliptic equations that makes use of domain decomposition,an accelerated Schwarz framework,and two-layer neural networks to approximate the boundary-to-boundarymap for the subdomains,which is the key step in the Schwarz ***,the boundary-to-boundary map requires solution of boundary-value elliptic problems on each *** leveraging the compressibility of multiscale problems,our approach trains the neural network offline to serve as a surrogate for the usual implementation of the boundary-to-boundary *** method is applied to a multiscale semilinear elliptic equation and a multiscale p-Laplace *** both cases we demonstrate significant improvement in efficiency as well as good accuracy and generalization performance.

关键词： Nonlinear homogenization Multiscale elliptic problem Neural networks Do-main decomposition

Micromolded honeycomb scaffold design to support the generation of a bilayered RPE and photoreceptor cell construct

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Bioactive Materials 2023年第12期30卷 142-153页

作者： In-Kyu Lee Ruosen Xie Agustin Luz-Madrigal Seunghwan Min Jingcheng Zhu Jiahe Jin Kimberly L.Edwards M.Joseph Phillips Allison L.Ludwig David M.Gamm Shaoqin Gong Zhenqiang Ma Department of Electrical and Computer Engineering University of Wisconsin-MadisonMadisonWI53706USA wisconsin Institute for Discovery University of Wisconsin-MadisonMadisonWI53715USA Department of Ophthalmology and Visual Sciences University of Wisconsin-MadisonMadisonWI53705USA Department of Biomedical Engineering University of Wisconsin-MadisonMadisonWI53706USA McPherson Eye Research Institute University of Wisconsin-MadisonMadisonWI53705USA Waisman Center University of Wisconsin-MadisonMadisonWI53705USA Department of Comparative Biomedical Sciences University of Wisconsin–MadisonMadisonWI53706USA Department of Materials Science and Engineering University of Wisconsin-MadisonMadisonWI53706USA Department of Engineering Physics University of Wisconsin-MadisonMadisonWI53706USA Grainger Institute for Engineering University of Wisconsin-MadisonMadisonWI53706USA

Age-related macular degeneration(AMD)causes blindness due to loss of retinal pigment epithelium(RPE)and photoreceptors(PRs),which comprise the two outermost layers of the *** the small size of the macula and the importance of direct contact between RPE and PRs,the use of scaffolds for targeted reconstruction of the outer retina in later stage AMD and other macular dystrophies is particularly *** developed microfabricated,honeycomb-patterned,biodegradable poly(glycerol sebacate)(PGS)scaffolds to deliver organized,adjacent layers of RPE and PRs to the subretinal ***,an optimized process was developed to photocure PGS,shortening scaffold production time from days to *** resulting scaffolds robustly supported the seeding of human pluripotent stem cell-derived RPE and PRs,either separately or as a dual celllayered *** advanced,economical,and versatile scaffolds can accelerate retinal cell transplantation efforts and benefit patients with AMD and other retinal degenerative diseases.

关键词： Microfabrication Retina Scaffolds Stem cells Tissue engineering

Dark matter is darker

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Nuclear Science and Techniques 2023年第6期34卷 1-3页

作者： Yang Bai Department of Physics University of Wisconsin-MadisonMadisonWI53706USA

New results for directly searching for dark matter electromagnetic interactions have been reported by the PandaX *** study reveals the most stringent upper limits on dark matter charge radius,millicharge,magnetic dipole moment,electric dipole moment,and anapole moment to *** findings demonstrate that dark matter is significantly darker than previously anticipated.

关键词： dipole moment charge

Added-value of GEO-hyperspectral Infrared Radiances for Local Severe Storm Forecasts Using the Hybrid OSSE Method

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Advances in Atmospheric Sciences 2021年第8期38卷 1315-1333页

作者： Pei WANG Zhenglong LI Jun LI Timothy JSCHMIT Cooperative Institute for Meteorological Satellite Studies University of Wisconsin-MadisonMadisonWI53706USA Advanced Satellite Product Branch Center for Satellite Applications and ResearchNESDIS/NOAAMadisonWI53706USA

High spectral resolution(or hyperspectral)infrared(IR)sounders onboard low earth orbiting satellites provide high vertical resolution atmospheric information for numerical weather prediction(NWP)*** contrast,imagers on geostationary(GEO)satellites provide high temporal and spatial resolution which are important for monitoring the moisture associated with severe weather systems,such as rapidly developing local severe storms(LSS).A hyperspectral IR sounder onboard a geostationary satellite would provide four-dimensional atmospheric temperature,moisture,and wind profiles that have both high vertical resolution and high temporal/spatial *** this work,the added-value from a GEO-hyperspectral IR sounder is studied and discussed using a hybrid Observing System Simulation Experiment(OSSE)method.A hybrid OSSE is distinctively different from the traditional OSSE in that,(a)only future sensors are simulated from the nature run and(b)the forecasts can be evaluated using real *** avoids simulating the complicated observation characteristics of the current systems(but not the new proposed system)and allows the impact to be assessed against real *** Cross-track Infrared Sounder(CrIS)full spectral resolution(FSR)is assumed to be onboard a GEO for the impact studies,and the GEO CrIS radiances are simulated from the ECMWF Reanalysis v5(ERA5)with the hyperspectral IR all-sky radiative transfer model(HIRTM).The simulated GEO CrIS radiances are validated and the hybrid OSSE system is verified before the impact *** LSS cases from 2018 and 2019 are selected to evaluate the value-added impacts from the GEO CrIS-FSR *** impact studies show improved atmospheric temperature,moisture,and precipitation forecasts,along with some improvements in the wind *** added-value,consisting of an overall 5%Root Mean Square Error(RMSE)reduction,was found when a GEO CrIS-FSR is used in replacement of LEO ones indicat-ing the potential for a

关键词： GEO hyperspectral IR hybrid OSSE satellite data assimilation