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Physical Review E 2017年第2期95卷 023201-023201页

作者： Hao Liu Yin Zhang Wei Kang Ping Zhang Huiling Duan X. T. He HEDPS Center for Applied Physics and Technology College of Engineering Peking University Beijing 100871 China Department of Mechanics and Engineering Science College of Engineering Peking University Beijing 100871 China Collaborative Innovation Center of IFSA (CICIFSA) Shanghai Jiao Tong University Shanghai 200240 China Institute of Applied Physics and Computational Mathematics Beijing 100088 China

We present a molecular dynamics simulation of shock waves propagating in dense deuterium with the electron force field method [J. T. Su and W. A. Goddard, Phys. Rev. Lett. 99, 185003 (2007)], which explicitly takes the excitation of electrons into consideration. Nonequilibrium features associated with the excitation of electrons are systematically investigated. We show that chemical bonds in D2 molecules lead to a more complicated shock wave structure near the shock front, compared with the results of classical molecular dynamics simulation. Charge separation can bring about accumulation of net charges on large scales, instead of the formation of a localized dipole layer, which might cause extra energy for the shock wave to propagate. In addition, the simulations also display that molecular dissociation at the shock front is the major factor that accounts for the “bump” structure in the principal Hugoniot. These results could help to build a more realistic picture of shock wave propagation in fuel materials commonly used in the inertial confinement fusion.

关键词： Shock waves Shock waves & discontinuities in plasma Inertially confined plasmas Molecular dynamics

Symmetrized importance samplers for stochastic differential equations

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arXiv 2017年

作者： Leach, Andrew Lin, Kevin K. Morzfeld, Matthias Program in Applied Mathematics University of Arizona 617 N. Santa Rita Ave. TucsonAZ85721 United States Department of Mathematics University of Arizona 617 N. Santa Rita Ave. TucsonAZ85721 United States

We study a class of importance sampling methods for stochastic differential equations (SDEs). A small-noise analysis is performed, and the results suggest that a simple symmetrization procedure can significantly improve the performance of our importance sampling schemes when the noise is not too large. We demonstrate that this is indeed the case for a number of linear and nonlinear examples. Potential applications, e.g., data assimilation, are discussed. Copyright © 2017, The Authors. All rights reserved.

关键词： Importance sampling

Snowmass 2021 CMB-S4 White Paper

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arXiv 2022年

作者： Abazajian, Kevork Abdulghafour, Arwa Addison, Graeme E. Adshead, Peter Ahmed, Zeeshan Ajello, Marco Akerib, Daniel Allen, Steven W. Alonso, David Alvarez, Marcelo Amin, Mustafa A. Amiri, Mandana Anderson, Adam Ansarinejad, Behzad Archipley, Melanie Arnold, Kam S. Ashby, Matt Aung, Han Baccigalupi, Carlo Baker, Carina Bakshi, Abhishek Bard, Debbie Barkats, Denis Barron, Darcy Barry, Peter S. Bartlett, James G. Barton, Paul Thakur, Ritoban Basu Battaglia, Nicholas Beall, Jim Bean, Rachel Beck, Dominic Belkner, Sebastian Benabed, Karim Bender, Amy N. Benson, Bradford A. Besuner, Bobby Bethermin, Matthieu Bhimani, Sanah Bianchini, Federico Biquard, Simon Birdwell, Ian Bischoff, Colin A. Bleem, Lindsey Bocaz, Paulina Bock, James J. Bocquet, Sebastian Boddy, Kimberly K. Richard Bond, J. Borrill, Julian Bouchet, François R. Brinckmann, Thejs Brown, Michael L. Bryan, Sean Buza, Victor Byrum, Karen Calabrese, Erminia Calafut, Victoria Caldwell, Robert Carlstrom, John E. Carron, Julien Cecil, Thomas Challinor, Anthony Chan, Victor Chang, Clarence L. Chapman, Scott Charles, Eric Chauvin, Eric Cheng, Cheng Chesmore, Grace Cheung, Kolen Chinone, Yuji Chluba, Jens Cho, Hsiao-Mei Sherry Choi, Steve Clancy, Justin Clark, Susan Cooray, Asantha Coppi, Gabriele Corlett, John Coulton, Will Crawford, Thomas M. Crites, Abigail Cukierman, Ari Cyr-Racine, Francis-Yan Dai, Wei-Ming Daley, Cail Dart, Eli Daues, Gregorg de Haan, Tijmen Deaconu, Cosmin Delabrouille, Jacques Derylo, Greg Devlin, Mark Di Valentino, Eleonora Dierickx, Marion Dober, Brad Doriese, Randy Duff, Shannon Dutcher, Daniel Dvorkin, Cora Dünner, Rolando Eftekhari, Tarraneh Eimer, Joseph El Bouhargani, Hamza Elleflot, Tucker Emerson, Nick Errard, Josquin Essinger-Hileman, Thomas Fabbian, Giulio Fanfani, Valentina Fasano, Alessandro Feng, Chang Ferraro, Simone Filippini, Jeffrey P. Flauger, Raphael Flaugher, Brenna Fraisse, Aurelien A. Frisch, Josef Frolov, Andrei Galitzki, Nicholas Gallardo, Patricio A. Galli, Silvia Ganga, Ken Gerbino, Martina Giannakopoulos, Christos G University of California IrvineCA92697 United States School of Physics The University of Melbourne ParkvilleVIC3010 Australia Johns Hopkins University BaltimoreMD21218 United States Illinois Center for Advanced Studies of the Universe Department of Physics University of Illinois at Urbana-Champaign UrbanaIL61801 United States SLAC National Accelerator Laboratory Menlo ParkCA94025 United States Clemson University ClemsonSC29634 United States Stanford University StanfordCA94305 United States University of Oxford OxfordOX1 3RH United Kingdom University of California BerkeleyCA94720 United States Lawrence Berkeley National Laboratory BerkeleyCA94720 United States Department of Physics & Astronomy Rice University HoustonTX77005 United States University of British Columbia VancouverBCV6T 1Z1 Canada Fermi National Accelerator Laboratory BataviaIL60510 United States University of California La Jolla San DiegoCA92093 United States Harvard-Smithsonian Center for Astrophysics CambridgeMA02138 United States Department of Physics Yale University New HavenCT06520 United States SISSA International School for Advanced Studies Via Bonomea 265 Trieste34136 Italy IFPU - Institute for Fundamental Physics of the Universe Via Beirut 2 Trieste34014 Italy Department of Physics Harvard University CambridgeMA02138 United States Department of Physics and Astronomy University of New Mexico AlbuquerqueNM87131 United States Argonne National Laboratory LemontIL60439 United States School of Physics and Astronomy Cardiff University The Parade CardiffCF24 3AA United Kingdom CNRS IN2P3 Université Paris Diderot Paris Cedex 1375205 France California Institute of Technology PasadenaCA91125 United States Cornell University IthacaNY14853 United States National Institute of Standards and Technology Boulder CO80305 United States Département de Physique Théorique et CAP Université de Genève Genève 4CH-1211 Switzerland CNRS Sorbonne Un

The science case for CMB-S4 remains as exciting as ever, as evidenced by DOE CD-0 "Mission Need" approval and by the strong endorsement by the 2020 Decadal Survey of Astronomy and Astrophysics. In fact, the science case has become stronger as scientists spanning the particle physics and cosmology communities have explored the potential of the transformational measurements CMB-S4 will make to achieve its threshold-crossing science goals. The technology is well understood and field tested. The CMB-S4 Collaboration and Integrated Project Office are established and highly functioning. The project is well developed, has been extensively reviewed, and is on path to achieve DOE CD-1 and NSF PDR on the timescale of a year, depending on funding. © 2022, CC BY.

关键词： Astrophysics

On trees, tanglegrams, and tangled chains 28

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On trees, tanglegrams, and tangled chains

28th International Conference on Formal Power Series and Algebraic Combinatorics, FPSAC 2016

作者： Billey, Sara C. Konvalinka, Matjaž Matsen, Frederick A. Department of Mathematics University of Washington SeattleWA98195 United States Department of Mathematics University of Ljubljana & Institute for Mathematics Physics and Mechanics Ljubljana Slovenia Computational Biology Program Fred Hutchinson Cancer Research Center SeattleWA98109 United States

Tanglegrams are a class of graphs arising in computer science and in biological research on cospeciation and coevolution. They are formed by identifying the leaves of two rooted binary trees. The embedding of the trees in the plane is irrelevant for this application. We give an explicit formula to count the number of distinct binary rooted tanglegrams with n matched leaves, along with a simple asymptotic formula and an algorithm for choosing a tanglegram uniformly at random. The enumeration formula is then extended to count the number of tangled chains of binary trees of any length. This work gives a new formula for the number of binary trees with n leaves. Several open problems and conjectures are included along with pointers to several followup articles that have already appeared. © 2016 Discrete mathematics and Theoretical Computer Science (DMTCS), Nancy, France to reconstruct the historical associations between the phylogenies of host and parasite under a model of parasites switching hosts, which is an instance of the more general problem of cophylogeny estimation.

关键词： Binary trees

Millimeter light curves of Sagittarius A∗ observed during the 2017 Event Horizon Telescope campaign

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arXiv 2022年

作者： Wielgus, Maciek Marchili, Nicola Martí-Vidal, Iván Keating, Garrett K. Ramakrishnan, Venkatessh Tiede, Paul Fomalont, Ed Issaoun, Sara Neilsen, Joey Nowak, Michael A. Blackburn, Lindy Gammie, Charles F. Goddi, Ciriaco Haggard, Daryl Lee, Daeyoung Moscibrodzka, Monika Tetarenko, Alexandra J. Bower, Geoffrey C. Chan, Chi-Kwan Chatterjee, Koushik Chesler, Paul M. Dexter, Jason Doeleman, Sheperd S. Georgiev, Boris Gurwell, Mark Johnson, Michael D. Marrone, Daniel P. Mus, Alejandro Psaltis, Dimitrios Ripperda, Bart Witzel, Gunther Akiyama, Kazunori Alberdi, Antxon Alef, Walter Algaba, Juan Carlos Anantua, Richard Asada, Keiichi Azulay, Rebecca Bach, Uwe Baczko, Anne-Kathrin Ball, David Baloković, Mislav Barrett, John Bauböck, Michi Benson, Bradford A. Bintley, Dan Blundell, Raymond Boland, Wilfred Bouman, Katherine L. Boyce, Hope Bremer, Michael Brinkerink, Christiaan D. Brissenden, Roger Britzen, Silke Broderick, Avery E. Broguiere, Dominique Bronzwaer, Thomas Bustamante, Sandra Byun, Do-Young Carlstrom, John E. Ceccobello, Chiara Chael, Andrew Chatterjee, Shami Chen, Ming-Tang Chen, Yongjun Cho, Ilje Christian, Pierre Conroy, Nicholas S. Conway, John E. Cordes, James M. Crawford, Thomas M. Crew, Geoffrey B. Cruz-Osorio, Alejandro Cui, Yuzhu Davelaar, Jordy de Laurentis, Mariafelicia Deane, Roger Dempsey, Jessica Desvignes, Gregory Dhruv, Vedant Dzib, Sergio A. Eatough, Ralph P. Emami, Razieh Falcke, Heino Farah, Joseph Fish, Vincent L. Alyson Ford, H. Fraga-Encinas, Raquel Freeman, William T. Friberg, Per Fromm, Christian M. Fuentes, Antonio Galison, Peter García, Roberto Gentaz, Olivier Gold, Roman Gómez-Ruiz, Arturo I. Gómez, José L. Gu, Minfeng Hada, Kazuhiro Haworth, Kari Hecht, Michael H. Hesper, Ronald Ho, Luis C. Ho, Paul Honma, Mareki Huang, Chih-Wei L. Huang, Lei Hughes, David H. Ikeda, Shiro Violette Impellizzeri, C.M. Inoue, Makoto James, David J. Jannuzi, Buell T. Janssen, Michael Jeter, Britton Jiang, Wu Jiménez-Rosales, Alejandra Jorstad, Svetlana Joshi, Abhishek V. Jung, Taehyun Karami, Mansour Karupp Max-Planck-Institut für Radioastronomie Auf dem Hügel 69 BonnD-53121 Germany Italian ALMA Regional Centre INAF-Istituto di Radioastronomia Via P. Gobetti 101 BolognaI-40129 Italy Departament d’Astronomia i Astrofísica Universitat de València C. Dr. Moliner 50 Burjassot ValènciaE-46100 Spain Observatori Astronòmic Universitat de València C. Catedrático José Beltrán 2 Paterna ValenciaE-46980 Spain Center for Astrophysics Harvard & Smithsonian 60 Garden Street CambridgeMA02138 United States Astronomy Department Universidad de Concepción Casilla 160-C Concepción Chile Finnish Centre for Astronomy with ESO University of Turku FI-20014 Finland Aalto University Metsähovi Radio Observatory Metsähovintie 114 KylmäläFI-02540 Finland Harvard University 20 Garden Street CambridgeMA02138 United States National Radio Astronomy Observatory 520 Edgemont Road CharlottesvilleVA22903 United States NASA Hubble Fellowship Program Einstein Fellow United States Villanova University Mendel Science Center Rm. 263B 800 E Lancaster Ave VillanovaPA19085 United States Physics Department Washington University CB 1105 St LouisMO63130 United States Department of Physics University of Illinois 1110 West Green Street UrbanaIL61801 United States Department of Astronomy University of Illinois at Urbana-Champaign 1002 West Green Street UrbanaIL61801 United States Dipartimento di Fisica Università degli Studi di Cagliari SP Monserrato-Sestu km 0.7 MonserratoI-09042 Italy INAF - Osservatorio Astronomico di Cagliari Via della Scienza 5 CA Selargius09047 Italy Department of Physics McGill University 3600 rue University MontréalQCH3A 2T8 Canada McGill Space Institute McGill University 3550 rue University MontréalQCH3A 2A7 Canada Radboud University P.O. Box 9010 Nijmegen6500 GL Netherlands Department of Physics and Astronomy Texas Tech University LubbockTX79409-1051 United States Institute of Astronomy and Astrophysics Academia Sinica 645 N. A’oho

The Event Horizon Telescope (EHT) observed the compact radio source, Sagittarius A∗ (Sgr A∗), in the Galactic Center on 2017 April 5-11 in the 1.3 millimeter wavelength band. At the same time, interferometric array data from the Atacama Large Millimeter/submillimeter Array and the Submillimeter Array were collected, providing Sgr A∗ light curves simultaneous with the EHT observations. These data sets, complementing the EHT very-long-baseline interferometry, are characterized by a cadence and signal-to-noise ratio previously unattainable for Sgr A∗ at millimeter wavelengths, and they allow for the investigation of source variability on timescales as short as a minute. While most of the light curves correspond to a low variability state of Sgr A∗, the April 11 observations follow an X-ray flare, and exhibit strongly enhanced variability. All of the light curves are consistent with a red noise process, with a power spectral density (PSD) slope measured to be between -2 and -3 on timescales between 1 min and several hours. Our results indicate a steepening of the PSD slope for timescales shorter than 0.3 h. The spectral energy distribution is flat at 220 GHz and there are no time-lags between the 213 and 229 GHz frequency bands, suggesting low optical depth for the event horizon scale source. We characterize Sgr A∗’s variability, highlighting the different behavior observed just after the X-ray flare, and use Gaussian process modeling to extract a decorrelation timescale and a PSD slope. We also investigate the systematic calibration uncertainties by analyzing data from independent data reduction pipelines. © 2022, CC BY.

关键词： Signal to noise ratio

Optimization of second order spatially distributed systems with multiple interconnected actuator/sensor pairs

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IFAC-PapersOnLine 2016年第18期49卷 476-481页

作者： Demetriou, Michael A. Fahroo, Fariba Aerospace Engineering Program Mechanical Engineering Department Worcester Polytechnic Institute WorcesterMA01609 United States Department of Applied Mathematics Naval Postgraduate School MontereyCA93943 United States

This work considers the economic aspects in control implementation of second order spatially distributed systems. By opting to use multiple actuator/sensor pairs with limited capacity, instead of a single actuator/sensor pair with higher price and larger capacity, this work provides a first view into the economic, computational and communication aspects. Considering a large number of actuator/sensor pairs and the a priori defined controller architecture of static output feedback along with the collocation assumption of the actuators and sensors, the resulting closed-loop system is expressed in terms of a static output feedback gain matrix that defines the communication amongst the actuator/sensor pairs. The design problem is then to find the values of the static feedback gain matrix in order to optimize a performance measure. Using the energy of the second order infinite dimensional system as the performance measure, the resulting optimization is expressed in terms of the solution to a parameterized operator Lyapunov equation. Simulation studies of the wave PDE in one spatial dimension for different communication topologies, reveal the effects of communication on the performance of the closed loop system. © 2016

关键词： Actuators Closed loop systems Feedback control Lyapunov functions Spatial distribution Actuator/sensor Communication topologies Controller architectures Distributed parameter systems Infinite dimensional system Second order systemss Spatially distributed system Static output feedback

Fast acoustic source imaging using multi-frequency sparse data

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arXiv 2017年

作者： Alzaalig, Ala Hu, Guanghui Liu, Xiaodong Sun, Jiguang Department of Mathematical Sciences Michigan Technological University Beijing Computational Science Research Center Beijing100193 China Institute of Applied Mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Department of Mathematical Sciences Michigan Technological University College of Mathematical Sciences University of Electronic Science and Technology of China

We consider the acoustic source imaging problems using multiple frequency data. Using the data of one observation direction/point, we prove that some information (size and location) of the source support can be recovered. A non-iterative method is then proposed to image the source for the Helmholtz equation using multiple frequency far field data of one or several observation directions. The method is simple to implement and extremely fast since it only computes an indicator function on the interested domain using only matrix vector multiplications. Numerical examples are presented to validate the effectiveness of the *** Codes 35P25, 35Q30, 45Q05, 78A46 Copyright © 2017, The Authors. All rights reserved.

关键词： Iterative methods

Genome-wide association study of long COVID

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Nature Genetics 2025年 1-16页

作者： Lammi, Vilma Nakanishi, Tomoko Jones, Samuel E. Andrews, Shea J. Karjalainen, Juha Cortés, Beatriz O’Brien, Heath E. Ochoa-Guzman, Ana Fulton-Howard, Brian E. Broberg, Martin Haapaniemi, Hele H. Kanai, Masahiro Pirinen, Matti Schmidt, Axel Mitchell, Ruth E. Mousas, Abdou Mangino, Massimo Huerta-Chagoya, Alicia Sinnott-Armstrong, Nasa Cirulli, Elizabeth T. Vaudel, Marc Kwong, Alex S. F. Maiti, Amit K. Marttila, Minttu M. Posner, Daniel C. Rodriguez, Alexis A. Batini, Chiara Minnai, Francesca Dearman, Anna R. Warmerdam, C. A. Robert Sequeros, Celia B. Winkler, Thomas W. Jordan, Daniel M. Rešcenko, Raimonds Miano, Lorenzo Lane, Jacqueline M. Chung, Ryan K. Guillen-Guio, Beatriz Leavy, Olivia C. Carvajal-Silva, Laura Aguilar-Valdés, Kevin Frangione, Erika Guare, Lindsay Vergasova, Ekaterina Marouli, Eirini Striano, Pasquale Zainulabid, Ummu Afeera Kumar, Ashutosh Ahmad, Hajar Fauzan Edahiro, Ryuya Azekawa, Shuhei Maj, Carlo Pensel, Max C. Miller, Abigail Nöthen, Markus M. Behzad, Pari Schultz, Sonja Heggemann, Julia Balla, Daniella Morrison, David R. Mooser, Vincent Perley, Danielle Ragoussis, Jiannis Rousseau, Simon Shi, Fangyi Lathrop, G. Mark Yanishevsky, Solomia Laurent, Laetitia Auld, Daniel Bertrand, Mylene Boisclair, Ariane Bourque, Guillaume Bujold, David Durand, Madeleine Adra, Darin St-Cyr, Janick Niemi, Mari E. K. Iyengar, Sudha K. Cai, Tianxi Cho, Kelly Sarvadhavabhatla, Sannidhi Donaire, Maria Sophia Valenzuela-Jorquera, Héctor Lamoza, Eduardo Arévalo, Tamara V. Retamales-Ortega, Rocío Sanhueza, Sergio Selman, Carolina S. Silva, Andrea X. Alarcon, Teresa A. Martínez, Matías F. Quiroga, Romina Zuñiga-Pacheco, Paula Zapata-Contreras, Daniela Yáñez, Cristian E. Quiñones, Luis A. Tobar-Calfucoy, Eduardo A. Monardes-Ramírez, Virginia A. Signore, Iskra A. Guajardo, Lissette G. Figueroa, Alvaro Oróstica, Karen Y. Muñoz, Christian A. Fuentes-Guajardo, Macarena Bocchieri, Pamela Cabrera, Camilo Echeverria, Cesar A. Cerpa, Leslie C. Donoso, Gerardo Gutiérrez-Richards, Scarlett Nova-Lamperti, Estefania Saez Hidalgo Institute for Molecular Medicine Finland (FIMM) Helsinki Institute of Life Science (HiLIFE) University of Helsinki Helsinki Finland University of Helsinki Helsinki Finland Department of Human Genetics McGill University Montreal QC Canada Centre for Clinical Epidemiology Department of Medicine Lady Davis Institute Jewish General Hospital McGill University Montreal QC Canada Kyoto-McGill International Collaborative Program in Genomic Medicine Graduate School of Medicine Kyoto University Kyoto Japan Department of Genome Informatics Graduate School of Medicine the University of Tokyo Tokyo Japan Research Fellow Japan Society for the Promotion of Science Tokyo Japan Lady Davis Institute Jewish General Hospital McGill University Montreal QC Canada Department of Psychiatry and Behavioral Sciences University of California San Francisco San Francisco CA United States Program in Medical and Population Genetics Broad Institute of Harvard and MIT Cambridge MA United States Stanley Center for Psychiatric Research Broad Institute of Harvard and MIT Cambridge MA United States Analytic and Translational Genetics Unit Massachusetts General Hospital Boston MA United States Genomes for Life-GCAT Lab CORE Program Germans Trias i Pujol Research Institute (IGTP) Badalona Spain Grup de REcerca en Impacte de les Malalties Cròniques i les seves Trajectòries (GRIMTra) Barcelona Spain Germans Trias i Pujol Research Institute (IGTP) Badalona Spain Sano Genetics Limited London United Kingdom Unidad de Biología Molecular y Medicina Genómica Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán Mexico City Mexico Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán Mexico City Mexico Genetics and Genomic Sciences Icahn School of Medicine at Mount Sinai New York City NY United States Broad Institute Cambridge MA United States Analytical and Translational Genetics Unit Massachusetts General Hospital Harvard Medical School Boston MA United Sta

Infections can lead to persistent symptoms and diseases such as shingles after varicella zoster or rheumatic fever after streptococcal infections. Similarly, severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) infection can result in long coronavirus disease (COVID), typically manifesting as fatigue, pulmonary symptoms and cognitive dysfunction. The biological mechanisms behind long COVID remain unclear. We performed a genome-wide association study for long COVID including up to 6,450 long COVID cases and 1,093,995 population controls from 24 studies across 16 countries. We discovered an association of FOXP4 with long COVID, independent of its previously identified association with severe COVID-19. The signal was replicated in 9,500 long COVID cases and 798,835 population controls. Given the transcription factor FOXP4’s role in lung physiology and pathology, our findings highlight the importance of lung function in the pathophysiology of long COVID. © The Author(s) 2025.

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Self-Organized Kilotesla Magnetic-Tube Array in an Expanding Spherical Plasma Irradiated by kHz Femtosecond Laser Pulses

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Physical Review Letters 2018年第25期121卷 255002-255002页

作者： Shiyi Zhou Yafeng Bai Ye Tian Haiyi Sun Lihua Cao Jiansheng Liu State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 People’s Republic of China University of Chinese Academy of Sciences Beijing 100049 People’s Republic of China Institute of Applied Physics and Computational Mathematics Beijing 100088 People’s Republic of China IFSA Collaborative Innovation Center Shanghai Jiao Tong University Shanghai 200240 People’s Republic of China Department of Physics Shanghai Normal University Shanghai 200234 People’s Republic of China Institute of Modern Optics Nankai University Tianjin 300000 People’s Republic of China

By using a millijoule kHz femtosecond laser pulse to irradiate a preformed expanding spherical plasma, which is driven by a prepulse with intensity of 1×1014 W/cm2, we observe fast-electron-mediated filamentary structures and an accompanying self-organized magnetic-tube array with 2000 T via time-resolved magneto-optical polarization rotation measurements. We reveal that these periodical filamentary structures predominantly originate from ejected energetic electron flows from the inner denser region of the spherical plasma, which will induce the electron Weibel instability and magnetic field organization and amplification in the expanding plasma in 2 ps. These results open new paths to investigate ampliﬁcation of intense magnetic fields and the radiation signature from gamma-ray bursts just by means of a much smaller and robust experimental platform.

关键词： Laser-plasma interactions Magnetic field generation & plasma dynamo Plasma instabilities Weibel instability Femtosecond laser irradiation

Transport effects on multiple-component reactions in optical biosensors

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arXiv 2017年

作者： Evans, Ryan M. Edwards, David A. Applied and Computational Mathematics Division Information and Technology Laboratory National Institute of Standards and Technology GaithersburgMD20899 United States Department of Mathematical Sciences University of Delaware NewarkDE19716 United States

Optical biosensors are often used to measure kinetic rate constants associated with chemical reactions. Such instruments operate in the surface-volume configuration, in which ligand molecules are convected through a fluid-filled volume over a surface to which receptors are confined. Currently, scientists are using optical biosenors to measure the kinetic rate constants associated with DNA translesion synthesis-a process critical to DNA damage repair. Biosensor experiments to study this process involve multiple interacting components on the sensor surface. This multiple-component biosensor experiment is modeled with a set of nonlinear Integrodifferential Equations (IDEs). It is shown that in physically relevant asymptotic limits these equations reduce to a much simpler set of Ordinary Differential Equations (ODEs). To verify the validity of our ODE approximation, a numerical method for the IDE system is developed and studied. Results from the ODE model agree with simulations of the IDE model, rendering our ODE model useful for parameter estimation. Copyright © 2017, The Authors. All rights reserved.

关键词： Integrodifferential equations