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Type Ia Supernova Explosions in Binary Systems:A Review

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Research in Astronomy and Astrophysics 2023年第8期23卷 10-52页

作者： Zheng-Wei Liu friedrich k.Röpke Zhanwen Han Yunnan Observatories Chinese Academy of Sciences(CAS)Kunming 650216China key Laboratory for the Structure and Evolution of Celestial Objects CASKunming 650216China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Zentrum für Astronomie der Universität Heidelberg Institut für Theoretische AstrophysikPhilosophenweg 12D-69120 HeidelbergGermany Heidelberger Institut für Theoretische Studien Schloss-Wolfsbrunnenweg 35D-69118 HeidelbergGermany

Type Ia supernovae(SNe Ia)play a key role in the fields of astrophysics and *** is widely accepted that SNe Ia arise from thermonuclear explosions of white dwarfs(WDs)in binary ***,there is no consensus on the fundamental aspects of the nature of SN Ia progenitors and their actual explosion *** fundamentally flaws our understanding of these important astrophysical *** this review,we outline the diversity of SNe Ia and the proposed progenitor models and explosion *** discuss the recent theoretical and observational progress in addressing the SN Ia progenitor and explosion mechanism in terms of the observables at various stages of the explosion,including rates and delay times,pre-explosion companion stars,ejecta–companion interaction,early excess emission,early radio/X-ray emission from circumstellar material interaction,surviving companion stars,late-time spectra and photometry,polarization signals and supernova remnant *** the efforts from both the theoretical and observational sides,questions of how the WDs reach an explosive state and what progenitor systems are more likely to produce SNe Ia remain *** single published model is able to consistently explain all observational features and the full diversity of SNe *** may indicate that either a new progenitor paradigm or an improvement in current models is needed if all SNe Ia arise from the same *** alternative scenario is that different progenitor channels and explosion mechanisms contribute to SNe *** the next decade,the ongoing campaigns with the James Webb Space Telescope,Gaia and the Zwicky Transient Facility,and upcoming extensive projects with the Vera *** Observatory's Legacy Survey of Space and Time and the Square kilometre Array will allow us to conduct not only studies of individual SNe Ia in unprecedented detail but also systematic investigations for different subclasses of SNe *** will advance theory and observation

关键词： (stars:)binaries(including multiple) close-methods numerical-(stars )supernovae general

Yield Improvement and Advanced Defect Control——Driving Forces for Modeling of Bulk Crystal Growth

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Journal of Rare Earths 2006年第z1期24卷 200-207页

作者： Georg Mueller Jochen friedrich Crystal Growth Laboratory University Erlangen-Nürnberg (WW6) and Fraunhofer Institute of Integrated Systems and Device Technology (IISB) Martensstrasse 7 D-91058 Erlangen Germany Crystal Growth Laboratory University Erlangen-Nürnberg (WW6) and Fraunhofer Institute of Integrated Systems and Device Technology (IISB) Martensstrasse 7 D-91058 Erlangen Germany

Yield improvement and advanced defect control can be identified as the driving forces for modeling of industrial bulk crystal growth. Yield improvement is mainly achieved by upscaling of the whole crystal growth apparatus and increased processing windows with more tolerances for parameter variations. Advanced defect control means on one hand a reduction of the number of deficient crystal defects and on the other hand the formation of beneficial crystal defects with a uniform distribution and well defined concentrations in the whole crystal. This "defect engineering" relates to the whole crystal growth process as well as the following cooling and optional annealing processes, respectively. These topics were illustrated in the paper by examples of modeling and experimental results of bulk growth of silicon (Si), gallium arsenide (GaAs), indium phosphide (InP) and calcium fluoride (CaF2). These examples also involve the state of the art of modeling of the most important melt growth techniques, crystal pulling (Czochralski methods) and vertical gradient freeze (Bridgman-type methods).

关键词： yield improvement advanced defect control crystal growth

Plant recruitment and survival as indicators of ecological restoration success in abandoned pasture land in Nurcoung,Victoria,Australia

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Ecological Processes 2013年第1期2卷 380-392页

作者： Singarayer k Florentine Jessica Gardner friedrich P Graz Sean Moloney School of Science Information Technology and Engineering Federation University AustraliaP.O.Box 663Mt.Helen 3353VICAustralia Greening Australia NC2 Building62 Main StreetNatimuk 3409Australia Department of Land Management Polytechnic of Namibia13Storch Str.P/Bag 13388WindhoekNamibia Department of Botany James Cook University1James Cook DrTownsville CityQLD 4811Australia

Introduction:One of the major impediments to developing better restoration strategies is the inadequate documentation of past restoration *** 2008,Greening Australia commenced ecological restoration on the Nurcoung property in Victoria to enhance local biodiversity,and in this paper we report on the habitat restoration outcomes in the three Ecological Vegetation Classes(EVC)found on this ***:Permanent sample plots(12×20 m)were randomly established in July 2010 in each of the restoration areas,with 9,10,and 24 plots demarcated in Shallow Sands Woodland(SSW),Heathy Woodland(HW),and Sandstone Ridge Woodlands(SRW),*** plots were prepared to include three seeded *** were assessed for seedling recruitment and survival in May 2010,April 2011,and May *** of individual seedling development included their height and cover,and their location within the ***:Our study shows that interaction between the age of the planted and direct-seeded vegetation and the nature of the EVC significantly affects the composition of plants and the soil surface in that species and,further,that soil cover parameters develop in different ways in the different experimental plots.A SIMPER analysis of soil cover parameters shows that most of the variation over the years of restoration is attributable to differences in the amount of bare soil recorded,rather than the amount of leaf-litter cover,and that these changes in soil cover parameters differ between EVCs over the sampling *** direct-seeding study shows that whilst most of the broadcast species were recruited,some species used in the Shallow Sands Woodland,the Heathy Woodland,and the Sandstone Ridge Shrubland did not show evidence of recruitment during the three sampling *** the density of most seedlings increased in subsequent sampling years,the planted species Callitris gracilis,Callitris rhomboidea,Hakea muelleriana,and Melaleuca lanceolata did not ***

关键词： soil planted seedling

Paleomagnetic age and palaeobiological significance of hominoid fossil strata of Yuanmou Basin in Yunnan

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Science China Earth Sciences 2004年第5期47卷 405-411页

作者： friedrich A. Heller Institute of Geophysics ETH Zurich Switzerland CH-8093

The two sections containing hominoid fossils in the Yuanmou Basin, Yunnan Prov-ince have been studied by means of magnetostratigraphy. The results are as follows. The Xiaohe section records over 8 polarity zones corresponding to Cande-kent95 time scale, including C3Br.1n, C3Br.1r, C3Br.2n, C3Br.2r, C4n.1n, C4n.1r, C4n.2n and C4n.2r, attaching to Late Mio-cene. This section comprises two layers of hominoid fossils: the lower layer (the 1st layer in fig. 4) which records the lower portion of C4n.2r with paleomagnetic age of 8.20—8.10 Ma and the upper layer (the 16th layer in fig. 4) which records C3Br.1r with paleomagnetic age of 7.20—7.15 Ma. So the age of hominoid fossils in the Xiaohe section is about 8.20—7.15 Ma. The Leilao section records over 11 polarity zones corresponding to Cande-kent95 time scale, including C3Br, C3Br.1n, C3Br.1r, C3Br.2n, C3Br.2r, C4n.1n, C4n.1r, C4n.2n, C4n.2r, C4n.3n and C4n.3r, attaching to Late Miocene. This section also consists of two layers of hominoid fossils: the lower layer (the 3rd layer in fig. 3) which records C4n.2r with the age of 8.20—8.10 Ma and the upper layer(the 19th layer in fig. 3) which records the middle portion of C3Br with the age of 7.15—7.1 Ma. So the age of hominoid fossils in the Leilao section is about 8.20—7.10 Ma. Sedimentary environments reflected in both sections are extremely similar, and the ages of hominoid fossils are of correspondency. The age of the lower and upper fossil layers is 8.20—8.10 Ma and 7.20—7.10 Ma respectively, which probably imply that hominoids living in Xiaohe and Leilao basins have uniform activity areas. There were hominoids activities all along during 8.00—7.00 MaBP in this field.

关键词： Yuanmou Basin, hominoid, paleomagnetism, chronology.

Dielectrophoretic assembly of carbon nanotubes and stability analysis

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Progress in Natural Science:Materials International 2013年第4期23卷 367-373页

作者： Libao An Craig friedrich College of Mechanical Engineering Hebei Provincial Key Laboratory of Inorganic Nonmetallic MaterialsHebei United University Department of Mechanical Engineering-Engineering Mechanics Multi-Scale Technologies InstituteMichigan Technological University

Nanoscale dimensions and remarkable properties of carbon nanotubes make them promising building blocks for *** requirement is the need to manipulate single or multiple carbon nanotubes to bridge electronic *** this paper,multi-walled carbon nanotubes with a variety of sizes are assembled onto electrodes using alternative current electric felds by *** effect of the dielectrophoretic parameters and the nanotube size as well as the length uniformity on the assembly is experimentally ***–voltage characteristics of assembled carbon nanotubes are *** experimental results showed that both the dielectrophoretic parameters and length uniformity of carbon nanotubes have an infuence on the stability of assembly *** uniform carbon nanotubes with an appropriate length and suffcient stiffness,which are more controllable by dielectrophoresis,is necessary for an assembly of a small number of carbon nanotubes.

关键词： Carbon nanotube Assembly Dielectrophoresis Process parameter Stability

STRAIN-GRADIENT STRESS ANALYSIS IN SAINT-VENANT BENDING

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Acta Mechanica Sinica 1996年第3期12卷 225-242页

作者： friedrich Wilhelm Hecker Jerzy Tadeusz Pindera Technische Universitat Braunschweig D-38106 Braunschweig Germany University of Waterloo Waterloo Ontario N2L 3G1 Canada

Light beam deflections caused by stress or strain gradients are inves- tigated analytically and experimentally in homogeneous beam specimens which are subjected to a particular case of flexure with shear. This study is a generalization of the prior an alytical-experimental examination of strain-gradient light deflections produced in stressed plates, which had concentrated on the simplest case where in- formation of interest is collected along a line of symmetry of the stress field. Main purpose of the present investigation is to document the efficacy of the strain-gradient method in analysis of the general case of stress state. The most interesting stress state is that in a beam subjected to the Saint-Venant bending, where the transversal and the longitudinal axes of the beam are in pure shear. The obtained results are compared with the predictions of the developed analytical models and with the pre- dictions of Filon's stress function. The procedures of evaluating the photoelastic and material coefficients using strain-gradient techniques were tested positively.

关键词： experimental stress analysis applied mechanics optical methods light propagation strain-gradient light bending testing mathematical models

Influence of drag laws on pressure and bed material recirculation rate in a cold flow model of an 8 MW dual fluidized bed system by means of CPFD

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Particuology 2018年第1期16卷 70-81页

作者： Stephan kraft friedrich kirnbauer Hermann Hofbauer Bioenergy 2020+ GmbH Wiener Strasse 49 A- 7540 Gussing Austria TU Wien Institute of Chemical Engineering Getreidemarkt 9/166 Vienna Austria

A cold flow model of an 8 MW dual fluidized bed （DFB） system is simulated using the commercial compu- tational particle fluid dynamics （CPFD） software package Barracuda. The DFB system comprises a bubbling bed connected to a fast fluidized bed with the bed material circulating between them. As the hydrodynam- ics in hot DFB plants are complex because of high temperatures and many chemical reaction processes, cold flow models are used. Performing numerical simulations of cold flows enables a focus on the hydro- dynamics as the chemistry and heat and mass transfer processes can be put aside. The drag law has a major influence on the hydrodynamics, and therefore its influence on pressure, particle distribution, and bed material recirculation rate is calculated using Barracuda and its results are compared with experimental results. The drag laws used were energy-minimization multiscale （EMMS）, Ganser, Turton-Levenspiel, and a combination of Wen-Yu]Ergun. Eleven operating points were chosen for that study and each was calculated with the aforementioned drag laws. The EMMS drag law best predicted the pressure and dis- tribution of the bed material in the different parts of the DFB system. For predicting the bed material recirculation rate, the Ganser drag law showed the best results. However, the drag laws often were not able to predict the experimentally found trends of the bed material recirculation rate. Indeed, the drag law significantly influences the hydrodynamic outcomes in a DFB system and must be chosen carefully to obtain meaningful simulation results. More research may enable recommendations as to which drag law is useful in simulations ofa DFB system with CPFD.

关键词： Cold flow modeling Fluidization Computational particle fluid dynamics(CPFD) simulation Dual fluidized bed Computational fluid dynamics

Novel pharmacological strategies to prevent aortic complications in Marfan syndrome

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Journal of Geriatric Cardiology 2011年第4期8卷 254-257页

作者： Peter Matt friedrich Eckstein Division of Cardiac Surgery Basel University HospitalSpitalstrasse 21CH-4031 BaselSwitzerland

The Marfan syndrome(MFS)is a systemic connective tissue disorder caused by mutations in the FBN1 *** molecular studies,most performed in mouse models,revealed that the MFS is more a developmental abnormality with broad and complex effects on the morphogenesis and function of multiple organ ***1 haploinsufficiency and dysregulated transforming growth factor-beta(TGF-β)signaling seem to be critical for clinical manifestations in MFS including aortic root *** root aneurysm and aortic dissection represent the main causes of morbidity and mortality in *** importantly,TGF-βantagonism through angiotensin II type 1 receptor blockers(ARBs),for example losartan,has been shown to prevent and possibly reverse aortic root dilatation in a mouse model of MFS.A first human study on a small pediatric cohort confirmed those promising results in reducing the aortic root growth over a follow-up period of 12 to 47 ***,a large multicenter trial has been set up and results should be available *** therapeutic strategies which might be combined with losartan include traditionalβ-blockade,doxycyclin and *** management could offer the first potential for primary prevention of clinical manifestations in MFS.

关键词： Marfan syndrome aneurysm angiotensin receptor blocker

Collision risk-capacity tradeoff analysis of an en-route corridor model

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Chinese Journal of Aeronautics 2014年第1期27卷 125-135页

作者： Ye Bojia Hu Minghua John friedrich Shortle College of Civil Aviation Nanjing University of Aeronautics and Astronautics National key Laboratory of Air Traffic Flow Management Nanjing University of Aeronautics and Astronautics Center for Air Transportation Systems Research George Mason University

Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the main purposes of the en-route corridor. This paper analyzes the collision risk-capacity tradeoff using a combined discrete-continuous simulation method. A basic two-dimensional en-route flow corridor with performance rules is designed as the operational envi- ronment. A second-order system is established by combining the point mass model and the propor- tional derivative controller together to simulate the self-separation operations of the aircrafts in the corridor and the operation performance parameters from the User Manual for the Base of Aircraft Data are used in this research in order to improve the reliability. Simulation results indicate that the aircrafts can self-separate from each other efficiently by adjusting their velocities, and rationally set- ting the values of some variables can improve the rate and stability of the corridor with low risks of loss of separation.

关键词： Air traffic control Corridor Risk-capacity tradeoff Self-separation Simulation