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Time-stepping approach for solving upper-bound problems: Application to two-dimensional Rayleigh-Bénard convection

Physical Review E 2015年第4期92卷 043012-043012页

作者： Baole Wen Gregory P. Chini Rich R. Kerswell Charles R. Doering Program in Integrated Applied Mathematics University of New Hampshire Durham New Hampshire 03824 USA Center for Fluid Physics University of New Hampshire Durham New Hampshire 03824 USA The Institute for Computational Engineering and Sciences The University of Texas at Austin Austin Texas 78712 USA Department of Mechanical Engineering University of New Hampshire Durham New Hampshire 03824 USA School of Mathematics University of Bristol University Walk Bristol BS8 1TW United Kingdom Department of Physics University of Michigan Ann Arbor Michigan 48109-1040 USA Department of Mathematics University of Michigan Ann Arbor Michigan 48109-1043 USA Center for the Study of Complex Systems University of Michigan Ann Arbor Michigan 48109-1107 USA

An alternative computational procedure for numerically solving a class of variational problems arising from rigorous upper-bound analysis of forced-dissipative infinite-dimensional nonlinear dynamical systems, including the Navier-Stokes and Oberbeck-Boussinesq equations, is analyzed and applied to Rayleigh-Bénard convection. A proof that the only steady state to which this numerical algorithm can converge is the required global optimal of the relevant variational problem is given for three canonical flow configurations. In contrast with most other numerical schemes for computing the optimal bounds on transported quantities (e.g., heat or momentum) within the “background field” variational framework, which employ variants of Newton's method and hence require very accurate initial iterates, the new computational method is easy to implement and, crucially, does not require numerical continuation. The algorithm is used to determine the optimal background-method bound on the heat transport enhancement factor, i.e., the Nusselt number (Nu), as a function of the Rayleigh number (Ra), Prandtl number (Pr), and domain aspect ratio L in two-dimensional Rayleigh-Bénard convection between stress-free isothermal boundaries (Rayleigh's original 1916 model of convection). The result of the computation is significant because analyses, laboratory experiments, and numerical simulations have suggested a range of exponents α and β in the presumed Nu∼PrαRaβ scaling relation. The computations clearly show that for Ra≤1010 at fixed L=22,Nu≤0.106Pr0Ra5/12, which indicates that molecular transport cannot generally be neglected in the “ultimate” high-Ra regime.

关键词： RAYLEIGH-Benard convection RESEARCH BOUNDS (Mathematics) CONVECTIVE flow (Fluid dynamics) NATURAL heat convection NUSSELT number

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Global, regional, and national sex-specific burden and control of the HIV epidemic, 1990–2019, for 204 countries and territories: the Global Burden of Diseases Study 2019

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The Lancet HIV 2021年第10期8卷 e633-e651页

作者： Jahagirdar, Deepa Walters, Magdalene K. Novotney, Amanda Brewer, Edmond D. Frank, Tahvi D. Carter, Austin Biehl, Molly H. Abbastabar, Hedayat Abhilash, E.S. Abu-Gharbieh, Eman Abu-Raddad, Laith Jamal Adekanmbi, Victor Adeyinka, Daniel Adedayo Adnani, Qorinah Estiningtyas Sakilah Afzal, Saira Aghababaei, Soodabeh Ahinkorah, Bright Opoku Ahmad, Sajjad Ahmadi, Keivan Ahmadi, Sepideh Ahmadpour, Ehsan Ahmed, Muktar Beshir Rashid, Tarik Ahmed Salih, Yusra Ahmed Aklilu, Addis Akram, Tayyaba Akunna, Chisom Joyqueenet Al Hamad, Hanadi Alahdab, Fares Alanezi, Fahad Mashhour Aleksandrova, Ekaterina A. Alene, Kefyalew Addis Ali, Liaqat Alipour, Vahid Almustanyir, Sami Alvis-Guzman, Nelson Ameyaw, Edward Kwabena Amu, Hubert Andrei, Catalina Liliana Andrei, Tudorel Anvari, Davood Arabloo, Jalal Aremu, Olatunde Arulappan, Judie Atnafu, Desta Debalkie Quintanilla, Beatriz Paulina Ayala Ayza, Muluken Altaye Azari, Samad Darshan, B.B. Banach, Maciej Bärnighausen, Till Winfried Barra, Fabio Barrow, Amadou Basu, Sanjay Bazargan-Hejazi, Shahrzad Belay, Habtamu Gebrehana Berheto, Tezera Moshago Bezabhe, Woldesellassie Mequanint Bezabih, Yihienew Mequanint Bhagavathula, Akshaya Srikanth Bhardwaj, Nikha Bhardwaj, Pankaj Bhattacharyya, Krittika Bibi, Sadia Bijani, Ali Bisignano, Catherine Bolarinwa, Obasanjo Afolabi Boloor, Archith Boltaev, Azizbek A. Briko, Nikolay Ivanovich Buonsenso, Danilo Burkart, Katrin Butt, Zahid A. Cao, Chao Charan, Jaykaran Chatterjee, Souranshu Chattu, Soosanna Kumary Chattu, Vijay Kumar Choudhari, Sonali Gajanan Chu, Dinh-Toi Couto, Rosa A.S. Cowden, Richard G. Dachew, Berihun Assefa Dadras, Omid Dagnew, Amare Belachew Dahlawi, Saad M.A. Dai, Xiaochen Dandona, Lalit Dandona, Rakhi das Neves, José Degenhardt, Louisa Demeke, Feleke Mekonnen Desta, Abebaw Alemayehu Deuba, Keshab Dhamnetiya, Deepak Dhungana, Govinda Prasad Dianatinasab, Mostafa Diaz, Daniel Djalalinia, Shirin Doan, Linh Phuong Dorostkar, Fariba Edinur, Hisham Atan Effiong, Andem Eftekharzadeh, Sahar El Sayed Zaki, Maysaa Elayedath, Rajesh Elhadi, Institute for Health Metrics and Evaluation University of Washington Seattle WA United States Department of Health Metrics Sciences School of Medicine University of Washington Seattle WA United States Division of Allergy and Infectious Diseases University of Washington Seattle WA United States Department of Global Health University of Washington Seattle WA United States School of Social Work University of Washington Seattle WA United States Department of Medicine University of Washington Seattle WA United States Vagelos College of Physicians and Surgeones Columbia University Medical Center New York NY United States Division of Data Analytics and Delivery for Impact WHO Geneva Switzerland Advanced Diagnostic and Interventional Radiology Research Centre Tehran University of Medical Sciences Tehran Iran Multiple Sclerosis Research Centre Tehran University of Medical Sciences Tehran Iran School of Public Health Tehran University of Medical Sciences Tehran Iran Department of Epidemiology and Biostatistics Tehran University of Medical Sciences Tehran Iran Paediatric Chronic Kidney Disease Research Centre Tehran University of Medical Sciences Tehran Iran Department of Psychiatry Tehran University of Medical Sciences Tehran Iran Metabolomics and Genomics Research Centre Tehran University of Medical Sciences Tehran Iran Sina Trauma and Surgery Research Centre Tehran University of Medical Sciences Tehran Iran Research Centre for Immunodeficiencies Tehran University of Medical Sciences Tehran Iran Non-Communicable Diseases Research Centre Tehran University of Medical Sciences Tehran Iran Department of Botany Sree Narayana Guru College Chelannur Kozhikode India Clinical Sciences Department University of Sharjah Sharjah United Arab Emirates Mass Communication Department University of Sharjah Sharjah United Arab Emirates Department of Health-Care Policy and Research Weill Cornell Medical College in Qatar Doha Qatar Department of Population Medicine Ca

Background: The sustainable development goals (SDGs) aim to end HIV/AIDS as a public health threat by 2030. Understanding the current state of the HIV epidemic and its change over time is essential to this effort. This study assesses the current sex-specific HIV burden in 204 countries and territories and measures progress in the control of the epidemic. Methods: To estimate age-specific and sex-specific trends in 48 of 204 countries, we extended the Estimation and Projection Package Age-Sex Model to also implement the spectrum paediatric model. We used this model in cases where age and sex specific HIV-seroprevalence surveys and antenatal care-clinic sentinel surveillance data were available. For the remaining 156 of 204 locations, we developed a cohort-incidence bias adjustment to derive incidence as a function of cause-of-death data from vital registration systems. The incidence was input to a custom Spectrum model. To assess progress, we measured the percentage change in incident cases and deaths between 2010 and 2019 (threshold >75% decline), the ratio of incident cases to number of people living with HIV (incidence-to-prevalence ratio threshold <0·03), and the ratio of incident cases to deaths (incidence-to-mortality ratio threshold <1·0). Findings: In 2019, there were 36·8 million (95% uncertainty interval [UI] 35·1–38·9) people living with HIV worldwide. There were 0·84 males (95% UI 0·78–0·91) per female living with HIV in 2019, 0·99 male infections (0·91–1·10) for every female infection, and 1·02 male deaths (0·95–1·10) per female death. Global progress in incident cases and deaths between 2010 and 2019 was driven by sub-Saharan Africa (with a 28·52% decrease in incident cases, 95% UI 19·58–35·43, and a 39·66% decrease in deaths, 36·49–42·36). Elsewhere, the incidence remained stable or increased, whereas deaths generally decreased. In 2019, the global incidence-to-prevalence ratio was 0·05 (95% UI 0·05–0·06) and the global incidence-to-mortality ratio was

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Solitons in optical metamaterials with trial solution approach and Bäcklund transform of Riccati equation

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Journal of Computational and Theoretical Nanoscience 2015年第12期12卷 5940-5948页

作者： Arnous, A.H. Mirzazadeh, Mohammad Moshokoa, Seithuti Medhekar, Sarang Zhou, Qin Mahmood, M.F. Biswas, Anjan Belic, Milivoj Department of Engineering Mathematics and Physics Higher Institute of Engineering El Shorouk Egypt Department of Engineering Sciences University of Guilan Rudsar-Vajargah44891-63157 Iran Department of Mathematics and Statistics Tshwane University of Technology Pretoria0008 South Africa Centre for Applied Physics Central University of Jharkhand Brambe Ranchi835205 India School of Electronics and Information Engineering Wuhan Donghu University Wuhan430212 China Department of Mathematics Howard University WashingtonDC20059 United States Department of Mathematical Sciences Delaware State University DoverDE19901-2277 United States Department of Mathematics Faculty of Science King Abdulaziz University Jeddah21589 Saudi Arabia Science Program Texas A and M University at Qatar P.O. Box 23874 Doha Qatar

This paper obtains soliton solutions in optical metamaterials. There are a couple of integration techniques that are applied to the nonlinear Schrödinger's equation, with full nonlinearity, that serves as the governing model. These are trial solution approach and application of Bäcklund transform to Riccati equation. There are four types of nonlinear media that are studied in this paper. They are Kerr law that is also referred to as cubic law, power law, parabolic law occasionally referred to as cubic-quintic law and finally dual-power law nonlinearity. Bright, dark and singular soliton solutions are obtained in optical metamaterials with the aid of the two algorithms. As a byproduct of these two approaches, singular periodic solutions and plane wave solutions are also listed although these are not utilized in optical metamaterials. There are several constraint conditions that naturally fall out from the solution structure. These conditions guarantee the existence of these variety of solutions. Copyright © 2015 American Scientific Publishers All rights reserved.

关键词： Solitons

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Human neutralizing antibodies isolated from a Zika patient and their molecular determinants

Human neutralizing antibodies isolated from a Zika patient a...

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第十一届全国免疫学学术大会

作者： Wang Qihui Yang Huabing Liu Xiaoqing Dai Lianpan Ma Tong Qi Jianxun Wong Gary Peng Ruchao Liu Sheng Li Junfu Li Shihua Song Jian Liu Jianying He Jianhua Yuan Hui Xiong Ying Liao Yong Li Jianhua Yang Jianping Tong Zhou Griffin Bryan Bi Yuhai Liang Mifang Xu Xiaoning Qin Chuan Cheng Gong Wang Peiyi Qiu Xiangguo Kobinger Gary Shi Yi Yan Jinghua Gao Fu CAS Key Laboratory of Microbial Physiological and Metabolic Engineering Institute of Microbiology Chinese Academy of Sciences Shenzhen Key Laboratory of Pathogen and Immunity Shenzhen Third People’s Hospital School of Life Sciences Anhui University Jiangxi province center for disease control and prevention Research Network of Immunity and Health (RNIH) Beijing Institutes of Life Science Chinese Academy of Sciences CAS Key Laboratory of Pathogenic Microbiology and Immunology Institute of Microbiology Chinese Academy of Sciences CAS Center for Influenza Research and Early-warning (CASCIRE) Chinese Academy of Sciences School of Life Sciences University of Science and Technology of China Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases School of Medicine Tsinghua University Shanghai Institute of Applied Physics Chinese Academy of Sciences Ganzhou Prefecture Center for Disease Control and Prevention Special Pathogens Program National Microbiology Laboratory Public Health Agency of Canada National Institute for Viral Disease Control and Prevention Chinese Center for Disease Control and Prevention (China CDC) MRC Human Immunology Unit University of Oxford Key Laboratory of Human Diseases Comparative Medicine Ministry of Health Institute of Medical Laboratory Animal Science Chinese Academy of Medical Sciences Faculty of Biological Science University of Leeds College of Life Sciences University of Chinese Academy of Sciences Savaid Medical School University of Chinese Academy of Sciences

Zika virus infections are associated with fetal microcephaly,neurological complications and constitute a public health ***,we report the isolation of 13 specific,human-origin monoclonal antibodies from an imported Zika case to *** of the isolated antibodies(Z23 and Z3L1)demonstrate potent Zika-specific neutralization in vitro without binding or neutralizing activity against Zika’s closest relative Dengue virus(DENV)1-4,

关键词： Zika virus envelope protein human neutralizing MAbs B cell sequencing crystal structure Cryo-EM

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Symmetry-protected mode coupling near normal incidence for narrow-band transmission filtering in a dielectric grating

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Physical Review B 2014年第16期89卷 165111-165111页

作者： J. M. Foley S. M. Young J. D. Phillips Applied Physics Program University of Michigan Ann Arbor Michigan 48109 USA Electrical Engineering and Computer Science Department University of Michigan Ann Arbor Michigan 48109 USA Physics Department University of Michigan Ann Arbor Michigan 48109 USA

A narrow-band transmission filter is demonstrated near normal incidence that operates through relaxation of supported-mode selection rules and is explained in the context of group theory. We calculated the transverse magnetic and transverse electric dispersion relations of a dielectric grating in the subwavelength and near-wavelength region using finite element modal analysis and determine the modes' corresponding irreducible representations. Coupling to select transverse magnetic modes at normal incidence is optimized to yield broadband high reflectance that acts as the background for the transmission filter. While some modes couple at normal incidence, others are shown to remain inaccessible due to symmetry mismatch. Away from normal incidence, the reduced symmetry relaxes the selection rules, enabling weak coupling between the incident field and these symmetry-protected modes. This weak coupling produces narrow transmission bands within the opaque background. Furthermore, by choosing the plane of incidence to include or exclude the grating periodicity, we show that orthogonal mode sets can independently be selected to couple to the incident light, yielding separate transmission bands. This spectral filtering is experimentally demonstrated with a suspended silicon grating in the infrared spectrum (7–14μm), which agrees well with simulated transmittance spectra and modal analysis.

关键词： GROUP theory MODAL analysis DIELECTRICS SYMMETRIC functions FINITE element method

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Highly efficient (11.1%) small molecule multi-junction organic photovoltaic cells

Highly efficient (11.1%) small molecule multi-junction organ...

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2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)

作者： Xiaozhou Che Xin Xiao Stephen R. Forrest Applied Physics Program University of Michigan Ann Arbor MI USA Department of Electrical Engineering and Computer Science University of Michigan Ann Arbor MI USA

We present multi-junction small molecule organic photovoltaic (OPV) cells with efficiencies over 11%. The devices consist of two or three, vacuum thermally evaporated planar-mixed heterojunction sub-cells with minimal absorption overlap between the cells. By introducing a transparent interconnecting layer, a dual element (tandem) cell achieves a power conversion efficiency of 10.0 ± 0.5%. We further improve the cell performance by adding an additional (3 rd ) sub-cell that absorbs at the second order optical interference maximum within the stack. The triple-junction cell significantly improves the quantum efficiency at shorter wavelengths, achieving a power conversion efficiency of 11.1 ± 0.5%, which to our knowledge, is the highest reported for a multi-junction OPV cell in the scientific literature.

关键词： Absorption Photovoltaic cells Interference Adaptive optics Cathodes Current measurement Optical filters

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MULTI-VARIABLE MICRO OPTO-FLUIDIC RING RESONATOR SENSING WITH PLASMONIC NANOPARTICLE FILMS

MULTI-VARIABLE MICRO OPTO-FLUIDIC RING RESONATOR SENSING WIT...

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International Conference on Solid-State Sensors, Actuators and Microsystems

作者： C. Zhang L. K. Wright K. Scholten Xudong Fan E. T. Zellers Department of Environmental Health Sciences University of Michigan Ann Arbor MI USA Department of Chemistry University of Michigan Ann Arbor MI USA Applied Physics Program University of Michigan Ann Arbor MI USA Center for Wireless Integrated MicroSensing & Systems University of Michigan Ann Arbor MI USA

ISBN: (纸本)9781479989560

Localized surface plasmon resonance (LSPR) in films of thiolate- and dithianate-monolayer-protected gold nanoparticles (MPN) having different monolayers and Au core sizes (4, 5, and 40 nm), and probed at three visible wavelengths near the LSPR maximum, has been exploited to discriminate among 6 vapors with a single sensing film. Arrays of just two MPN films (4- or 5-nm core diameters) were also remarkably selective (> 95% discrimination) even probing each film with just a single wavelength. Initial results obtained from the first MPN-coated microfabricated optofluidic ring resonator sensor (μOFRR) used as a μGC detector are also presented and appear promising.

关键词： Vapor sensor localized surface plasmon resonance nanoparticle ring resonator gas chromatography

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Complexity in Surfaces of Densest Packings for Families of Polyhedra

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Physical Review X 2014年第1期4卷 011024-011024页

作者： Elizabeth R. Chen Daphne Klotsa Michael Engel Pablo F. Damasceno Sharon C. Glotzer School of Engineering and Applied Sciences Harvard University Cambridge Massachusetts 02138 USA Department of Chemical Engineering University of Michigan Ann Arbor Michigan 48109 USA Applied Physics Program University of Michigan Ann Arbor Michigan 48109 USA Department of Materials Science and Engineering University of Michigan Ann Arbor Michigan 48109 USA

Packings of hard polyhedra have been studied for centuries due to their mathematical aesthetic and more recently for their applications in fields such as nanoscience, granular and colloidal matter, and biology. In all these fields, particle shape is important for structure and properties, especially upon crowding. Here, we explore packing as a function of shape. By combining simulations and analytic calculations, we study three two-parameter families of hard polyhedra and report an extensive and systematic analysis of the densest known packings of more than 55 000 convex shapes. The three families have the symmetries of triangle groups (icosahedral, octahedral, tetrahedral) and interpolate between various symmetric solids (Platonic, Archimedean, Catalan). We find optimal (maximum) packing-density surfaces that reveal unexpected richness and complexity, containing as many as 132 different structures within a single family. Our results demonstrate the importance of thinking about shape not as a static property of an object, in the context of packings, but rather as but one point in a higher-dimensional shape space whose neighbors in that space may have identical or markedly different packings. Finally, we present and interpret our packing results in a consistent and generally applicable way by proposing a method to distinguish regions of packings and classify types of transitions between them.

关键词： Geometry

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Dielectric properties of ternary composites of triblock polymer surfactant, liquid crystal and organic solvent

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Journal of Advanced Dielectrics 2014年第3期4卷 33-39页

作者： M.R.Fisch Clinton Braganza L.C.Chien R.G.Petschek College of Applied Engineering Sustainabilityand Technology Kent State UniversityKentOhio 44242USA Liquid Crystal Institute and Chemical Physics Interdisciplinary Program Kent State University KentOhio 44242USA Department of Physics Case Western Reserve University10600 Euclid Ave.ClevelandOhio 44106USA

Dielectric spectroscopy,at room temperature(20℃),is used to study the dielectric response of ternary mixtures of commercial nematic liquid crystal mixtures E7 and E33,an organic solvent N-Methyl-2-Pyrrolidone(NMP)and a triblock polymers in the frequency range from 0.01Hz to *** results indicate a dielectric relaxation in the hectohertz ***,both E7 and NMP have rather large low frequency conductivities;however,the low frequency(0.01–10Hz)behavior of the mixtures has no such *** attribute this behavior to an ion getter effect of the triblock polymer *** ternary mixtures obtain a real dielectric constant near 230,and loss tangent less than 0.05 at frequencies near 10mHz.

关键词： Emulsion dielectric properties liquid crystal

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Calibrated Langevin-dynamics simulations of intrinsically disordered proteins

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Physical Review E 2014年第4期90卷 042709-042709页

作者： W. Wendell Smith Po-Yi Ho Corey S. O'Hern Department of Physics Yale University New Haven Connecticut 06520-8120 USA Integrated Graduate Program in Physical and Engineering Biology Yale University New Haven Connecticut 06520-8114 USA Department of Mechanical Engineering and Materials Science Yale University New Haven Connecticut 06520-8286 USA Department of Applied Physics Yale University New Haven Connecticut 06520-8267 USA Program in Computational Biology and Bioinformatics Yale University New Haven Connecticut 06520 USA

We perform extensive coarse-grained (CG) Langevin dynamics simulations of intrinsically disordered proteins (IDPs), which possess fluctuating conformational statistics between that for excluded volume random walks and collapsed globules. Our CG model includes repulsive steric, attractive hydrophobic, and electrostatic interactions between residues and is calibrated to a large collection of single-molecule fluorescence resonance energy transfer data on the interresidue separations for 36 pairs of residues in five IDPs: α−, β−, and γ-synuclein, the microtubule-associated protein τ, and prothymosin α. We find that our CG model is able to recapitulate the average interresidue separations regardless of the choice of the hydrophobicity scale, which shows that our calibrated model can robustly capture the conformational dynamics of IDPs. We then employ our model to study the scaling of the radius of gyration with chemical distance in 11 known IDPs. We identify a strong correlation between the distance to the dividing line between folded proteins and IDPs in the mean charge and hydrophobicity space and the scaling exponent of the radius of gyration with chemical distance along the protein.

关键词： LANGEVIN equations SIMULATION methods & models CONFORMATIONAL analysis MICROTUBULE-associated proteins HYDROPHOBIC compounds

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