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Type Ia Supernova Explosions in Binary Systems:A review

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

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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

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Electron–plasmon and electron–magnon scattering in ferromagnets from first principles by combining GW and GT self-energies

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npj Computational Materials 2021年第1期7卷 1619-1632页

作者： Dmitrii Nabok Stefan Blügel Christoph friedrich Peter Grünberg Institut and Institut for Advanced Simulation Forschungszentrum JülichJülich 52425Germany

This work combines two powerful self-energy techniques:the well-known GW method and a self-energy recently developed by us that describes renormalization effects caused by the scattering of electrons with magnons and Stoner *** GT selfenergy,which is fully k-dependent and contains infinitely many spin-flip ladder diagrams,was shown to have a profound impact on the electronic band structure of Fe,Co,and *** the present work,we refine the method by combining GT with the GW *** resulting GWT spectral functions exhibit strong lifetime effects and emergent dispersion *** are in an overall better agreement with experimental spectra than those obtained with GW or GT alone,even showing partial improvements over local-spin-density approximation dynamical mean-field *** performed analysis provides a basis for applying the GWT technique to a wider class of magnetic materials.

关键词： materials theory infinitely

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Ensuring adequate statistics in particle tracking experiments

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Particuology 2021年第6期19卷 43-54页

作者： C.r.k.Windows-Yule School of Chemical Engineering University of BirminghamEdgbastonBirmingham B152TTUnited Kingdom Institute for Multiscale Simulation Engineering of Advanced MaterialsFriedrich-Alexander Universitat Erlangen-NurnbergSchloBplatz 491054 ErlangenGermany

Particle tracking techniques such as magnetic particle tracking,radioactive particle tracking and positron emission particle tracking are widely used in academia and industry to image the dynamics of particulate and multiphase *** techniques can provide detailed data concerning a range of important,whole-field quantities based only on the time-averaged dynamics of a small number of tracer ***,in order for this data to be reliable,the duration over which these time-averages are taken must be suitably ***,the‘minimum averaging time’required to produce good statistics depends sensitively on the system in question and,at present,cannot be determined a priori in advance of an *** this paper,we take a step toward resolving this issue,using discrete element method simulations of a simple vibroﬂuidised granular bed to develop a series of scaling laws relating said minimum averaging time to a variety of key system *** scaling laws developed may be used by future experimentalists to predict the required averaging time for each given system during an experimental campaign,thus improving both the efficiency with which particle tracking techniques may be applied,and the reliability of the data produced thereby.

关键词： Granular Particle tracking Positron emission particle tracking radioactive particle tracking Magnetic particle tracking Particle tracking velocimetry

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高聚物塑性流动磨损机理研究

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高分子材料科学与工程 1997年第4期13卷 90-94页

作者：章明秋 k.friedrich 中山大学材料科学研究所

选用聚醚醚酮（ＰＥＥＫ）为对象，研究其无润滑条件下的滑动摩擦磨损行为，根据实验测得的有关特性，磨屑形态及试样摩擦面特征，提出了塑性流动磨损机理，解释了实验现象。

关键词：聚醚醚酮摩擦磨损滑动摩擦塑性流动高聚物

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表面接枝改性纳米二氧化硅填充聚丙烯的结晶行为

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高分子学报 2004年第2期14卷 184-190页

作者：容敏智章明秋潘顺龙 friedrich k. 中山大学材料科学研究所聚合物复合材料及功能材料教育部重点实验室广州510275 Institute for Composite Materials (IVW) University of Kaiserslautern

应用差示扫描量热方法研究了纳米二氧化硅 (SiO2 )及其表面接枝改性对聚丙烯 (PP)结晶过程、等温与非等温结晶动力学的影响 ,并研究了上述等温结晶的熔融行为和平衡熔点 .研究发现纳米SiO2 具有明显的异相成核效应 ,能够提高PP的结晶温... 详细信息

应用差示扫描量热方法研究了纳米二氧化硅 (SiO2 )及其表面接枝改性对聚丙烯 (PP)结晶过程、等温与非等温结晶动力学的影响 ,并研究了上述等温结晶的熔融行为和平衡熔点 .研究发现纳米SiO2 具有明显的异相成核效应 ,能够提高PP的结晶温度、熔融温度、结晶度和结晶速率 ,但降低聚丙烯结晶的完善程度 .粒子的表面接枝处理 ,因改善了粒子与基体的亲和性而有利于粒子成核效应的提高。

关键词：聚丙烯表面接枝改性纳米二氧化硅结晶行为差示扫描量热法

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纳米碳化硅填充环氧树脂复合材料的摩擦磨损特性

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复合材料学报 2004年第6期21卷 14-20页

作者：纪秋龙章明秋容敏智 WETZEL B friedrich k 中山大学材料科学研究所聚合物复合材料及功能材料教育部重点实验室 Institute for Composite Materials University of Kaiserslautern D-67663 Kaiserslautern Germany

　以提高环氧树脂的摩擦磨损性能为目的,研究了纳米碳化硅粒子填充环氧树脂复合材料的滑动干摩擦磨损特性,着重探讨纳米粒子表面接枝改性、纳米粒子含量、摩擦条件等对复合材料摩擦学性能的影响。通过对复合材料磨损表面的形貌分析,以... 详细信息

　以提高环氧树脂的摩擦磨损性能为目的,研究了纳米碳化硅粒子填充环氧树脂复合材料的滑动干摩擦磨损特性,着重探讨纳米粒子表面接枝改性、纳米粒子含量、摩擦条件等对复合材料摩擦学性能的影响。通过对复合材料磨损表面的形貌分析,以及复合材料的热变形性能和表面硬度的测定,探讨了复合材料的磨损机理。结果表明,纳米碳化硅粒子能在很低的含量下提高环氧树脂耐磨性、并降低其摩擦系数,而经过接枝处理后的纳米碳化硅粒子填充复合材料的上述性能改善更为明显,耐磨性比环氧树脂提高近4倍,摩擦系数降低36%。这说明在SiC纳米粒子表面引入聚丙烯酰胺接枝链后,由于界面的强相互作用(包括化学键合与链纠缠),有效地提高了复合材料的抵抗裂纹引发能力等性能,从而有利于改善其摩擦学性能。

关键词：纳米碳化硅接枝改性环氧树脂复合材料摩擦磨损

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Porous insights:IpaH7.8 reveals crystal-clear differences of gasdermins in mice and men

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Signal Transduction and Targeted Therapy 2023年第7期8卷 3209-3210页

作者： friedrich Alexander von Samson-Himmelstjerna Benedikt kolbrink Stefan krautwald Department of Nephrology and Hypertension University Hospital Schleswig-Holstein24105 KielGermany

Two recent back-to-back papers published in Nature provide new insights into the structural basis of gasdermin B(GSDMB)targeting by the secreted Shigella virulence effector IpaH7.8,the regulation of GSDMB’s pore-forming pyroptotic activity by alternative splicing,and into the inter-species differences regarding IpaH7.8-mediated inhibition of gasdermin D(GSDMD)activity.

关键词： insight Shigella activity

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Compression behavior of Sm)2Ti_2O_7-pyrochlore up to 50 GPa:single-crystal X-ray diffraction and density functional theory calculations

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Chinese Science Bulletin 2014年第36期59卷 5278-5282页

作者： Bjrn Winkler Alexandra friedrich Wolfgang Morgenroth Eiken Hausshl Victor Milman Chris r.Stanek kenneth J.Mc Clellan Geowissenschaften Goethe-Universitt Altenh ferallee 160438 Frankfurt am Main Germany Dassault Syste`mes BIOVIA 334 Science ParkCambridge CB4 0WN UK Los Alamos National Laboratory Los Alamos NM 87545 USA

Single-crystal X-ray diffraction at pressures up to 50 GPa has been employed to study the compression behavior of Sm2Ti2O7-pyrochlore. In contrast to earlier reports, we observed no pressure-induced amorphization or pressure-induced anion disorder up to 50 GPa. The experimental study has been complemented by density functional theory-based calculations. A combination of the theoretical and experimental data yields a bulk modulus of 185 GPa, significantly higher than a value which had been reported earlier. In comparison to earlier work, the current study provides more reliable data due to the use of neon as a pressure medium, which provides a more hydrostatic pressure than the aluminum, which had been employed as a pressure medium in the earlier studies. An analysis of the compressibility of Al2B2O7 pyrochlores shows an approximately linear dependence of the bulk modulus on the unit cell volume.

关键词：密度泛函理论压缩行为单晶X射线衍射烧绿石计算单晶X-射线衍射压力诱导体积弹性模量

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A Cognitive radio receiver Supporting Wide-Band Sensing

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Wireless Sensor Network 2009年第3期1卷 123-134页

作者： Volk.r BLASCHkE Tobias rENk friedrich k. JONDrAL Institut für Nachrichtentechnik Universitat Karlsruhe(TH)KarlsruheGermany

The specification of IEEE 802.22 defines the world-wide first cognitive radio (Cr) standard. Within a range of 40 MHz to 910 MHz Cr systems are allowed to allocate spectrum besides the currently established radio services like radio and TV broadcasting. In order to fulfill the regulative guidelines of interference limita-tions, a capable spectral sensing and user detection has to be provided. Due to the wide frequency range specified in IEEE 802.22 and the high dynamic range of signals allocated in this band there are high de-mands on the Cr receiver’s front-end. Especially the performance requirements on analog-to-digital con-verters increase significantly compared to current wireless systems. Based on measurements taken in this frequency range requirements to Cr’s ADCs are figured out. Furthermore, the measurement results are ana-lyzed regarding expectable allocation scenarios and their impacts to spectral sensing. Derived from this re-sults and a comparison of general spectral sensing mechanisms an approach for a Cr receiver supporting wide-band sensing is presented. Considering the apriori information resulting from scenario analysis and including adapted information processing in the terminal the ADC’s performance requirements can be re-duced.

关键词： Cognitive radio IEEE 802.22 Spectrum Sensing A/D Conversion

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