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The physics and astrophysics of Type Ia supernova explosions

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Frontiers of physics 2013年第2期8卷 111-115页

作者： Mike Guidry Bronson messer Dcparlment of Physics and Astronomy University of Tennessee. KnoxvilleUSA TN 37996 Physies Division Oak Ridge National Laboratory Oak RidgeUSA TN 37830 Computer Science and Mathematics Division Oak Ridge National Laboratory Oak RidgeUSA TN 37830 National Center for Computational Sciences Oak Ridge National Laboratory Oak Ridgv USA TN 37831

Asupernowt is a transient astronomical event of spectacular peak brightness that is associ-a ted with an exploding star. Supernovae exhibit a range of observational characteristics that historically h^ts led to a rich set of classsifications and sub-clmssifications. Despite the complex- ity of the obscrwttionally-based supernova, taxonomy, we now believe that all supernovae are caused by just one of two basic inechanisms：（i） the collapse of the core of a inassive star late in its litb, or （ii） a runaway thermonuclear explosion in a white dwarf. The former is terlned tile cor^-collapsc mechanism, and is powered by gravitational energy

关键词： astrophysics an exploding star the observationally-based

Tribological performance and microstructural evolution ofα-brass alloys as a function of zinc concentration

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Friction 2020年第6期8卷 1117-1136页

作者： Zhilong LIU Philipp messer-HANNEMANN Stephan LAUBE Christian GREINER Institute for Applied Materials(IAM) Karlsruhe Institute of Technology(KIT)Karlsruhe 76131Germany KIT IAM-CMS MikroTribologie CentrumμTC Karlsruhe 76131Germany

Tailoring a material's properties for low friction and little wear in a strategic fashion is a long-standing goal of materials *** deformation plays a major role when metals are employed in a sliding contact;therefore,the effects of stacking fault energy and mode of dislocation glide need to be ***,we investigated how a decrease in the stacking fault energy affects friction,wear,and the ensuing sub-surface microstructure *** samples with increasing zinc concentrations of 5,15,and 36 wt%were tested in non-lubricated sphere-on-plate contacts with a reciprocating linear tribometer against Si3N4 *** the sliding distance from 0.5(single trace)to 5,000 reciprocating cycles covered different stages in the lifetime of a sliding *** the results among the three alloys revealed a profound effect of the zinc concentration on the tribological ***15 and CuZn36 showed similar friction and wear results,whereas CuZn5 had a roughly 60%higher friction coefficient(COF)than the other two ***15 and CuZn36 had a much smaller wear rate than *** dislocation motion in CuZn5 and CuZn15 allowed for dislocation self-organization into a horizontal line about 150 nm beneath the contact after a single trace of the *** feature was absent in CuZn36 where owing to planar dislocation slip band-like features under a 45°angle to the surface were *** results hold the promise to help guide the future development of alloys tailored for specific tribological applications.

关键词： brass tribology sliding contact microstructure stacking fault energy electron microscopy

Species distribution of polymeric aluminium ferrum——timed complexation colorimetric analysis method of Al-Fe-Ferron

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Journal of Environmental Sciences 2001年第4期13卷 418-421页

作者： Hu, YY Tu, CQ Wu, hh S China Univ Technol Coll Paper & Environm Engn Guangzhou 510640 Peoples R China

The effects of the calorimetric buffer solutions were investigated while the two colorimetric reactions of AI-ferron complex and Fe-ferron complex occurred individually, and the effects of the testing wavelength and the pH of the solutions were also investigated. A timed complexatian colorimetric analysis method of Al-Fe-ferron in view of the total concentration of {AI + Fe} was then established to determine the species distribution of polymeric Al-Fe. The testing wavelength was recommended at 362 net and the testing pH value was 5. With a comparison of the ratios of n(Al)/n(Fe), the standard adsorption curves of the polymeric Al-Fe solutions were derived from the experimental results. Furthermore, the solutions' composition were carious in both the molar n(Al)/n(Fe) ratios, i.e. 0/0, 5/5, 9/1 and 0/10, and the concentrations associated with the total ( Al + Fe which ranged from 10(-5) to 10(-4) mol/L..

关键词： polymeric aluminum-ferrum species distribution timed complexation colarimetric analysis method Al-Fe-ferron

Electroencephalogram response in premature infants to different odors: a feasibility study

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World Journal of Pediatrics 2022年第12期18卷 845-848页

作者： Janine Gellrich Sandy Schlage Veronika messer Valentin A.Schriever Abteilung Neuropädiatrie Medizinische Fakultät Carl Gustav Carus Technische UniversitätDresdenGermany Klinik und Poliklinik für Kinder-und Jugendmedizin Medizinische Fakultät Carl Gustav CarusTechnische Universität DresdenFetscherstrasse 7401307DresdenGermany Center for Chronically Sick Children(Sozialpädiatrisches Zentrum SPZ)Charité-Universitätsmedizin BerlinBerlinGermany Department of Pediatric Neurology Charité-Universitätsmedizin BerlinBerlinGermany

The importance of olfaction for newborns,especially for mother-associated odors is well *** receptor neurons were found in preterm infants as early as 24–27 weeks of gestation[1].Therefore,it can be assumed that the olfactory sense is functioning in preterm infants[2],but only very little is known about olfactory processing at this *** studies dealing with the processing of olfactory stimuli have been conducted on mature ***,in 2001 a research group demonstrated,using near-infrared spectroscopy,that a change in blood oxygenation of premature infants could be detected in the orbitofrontal cortex after olfactory stimulation with disinfectant and detergent[3].Electroencephalogram(EEG)techniques have broadly been used to measure central odor processing in adults and children[4,5,6].

关键词： mother stimulation cortex

Cyclic Saturation Dislocation Pattern Observation in the Vicinity of Grain Boundaries by Electron Channeling Contrast Technique

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Journal of Materials Science & Technology 1998年第3期14卷 211-214页

作者： Zhang, ZF Li, XW Su, hh Wang, ZG Acad Sinica Inst Met Res State Key Lab Fatigue & Fracture Mat Shenyang 110015 Peoples R China

The cyclic saturation dislocation patterns within grains and in the vicinity of low-angle grain boundaries in fatigued copper crystal were successfully observed by electron channeling contrast technique in SEM. The results show that the dislocation patterns within grains consisted of typical two-phase structure, i.e. persistent slip bands (PSB) and veins. With increasing plastic strain amplitude (gamma(pl) greater than or equal to 1.7 x 10(-3)), large amount of PSBs and regular dislocation walls were observed. The dislocation walls and PSBs could cross through the low-angle grain boundaries continuously except that the dislocation-free zone (DFZs) appeared at some local regions. Combining with the cyclic stress-strain response and dislocation patterns, the effect of low-angle grain boundaries on cyclic deformation behavior was discussed.

关键词： Copper

Rb-Sr isotope dating of silicalite from the Dajiangping massive sulfide ore deposit,Guangdong Province

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Chinese Science Bulletin 1997年第23期42卷 1983-1985页

作者： Wang, HI Li, HY Wang, YX Wang, hh Nanjing Univ Dept Earth Sci Nanjing 210093 Peoples R China

THE Dajiangping pyrite ore deposit located in the Yunfu County of Guangdong Province is asuper-large pyrite ore deposit. Its age has not been defined so far because of the absence of fos-sil. This note is to use Rb-Sr isotope dating of silicalite to constrain the age of the ore depositand place special emphasis on its geological significance.

关键词： pyrite ore deposit silicalite Rb-Sr isotope ore-forming age.

Assessment of genotoxicity and cytotoxicity of standardized aqueous extract from leaves of Erythroxylum cuneatum in human HepG2 and WRL68 cells line

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Asian Pacific Journal of Tropical Medicine 2013年第10期6卷 811-816页

作者： RK Wesam AN Ghanya hh Mizaton M ILham A Aishah Faculty of Pharmacy Universiti Teknologi MARAShah AlamSelangor Department of Food Sciences and Technology Faculty of AgricultureUniversity of Sana'a Forest Research Institute of Malaysia(FRIM)

Objective:To investigate the cytotoxicity and the genotoxicity of standardized aqueous of dry leaves of Erythroxylum cuneatum(***)in human HepG2 and WRL68 ***:The cytoloxicity of *** extract was evaluated by both MTS and LDH *** study on *** extract was assessed by the single cell gel electrophoresis(comet assay).The protective effect of *** against menadione-induced cytotoxicity was also ***:Results from this study showed that *** extract exhibited cytotoxic activities towards the cells with IC_(50)value of(125±12)and(125±14)μg/mL for HepG2and WRL68 cells respectively,after 72 h incubation period as determined by MTS *** leakage was detected at(251±19)and(199.5±12.0)μg/mL for HepG2 and WRL68 *** study results showed that treatment with *** up to 1 mg/mL did not cause obvious DNA damage in WRL68 and HepG2 *** of *** did not show significant protection towards menadione in WRL68 and HepG2 ***:*** standardized aqueous extract might be developed in onler to establish new pharmacological possibilities for its application.

关键词： Erythroxylum cuneatu Cytotoxicity Genotoxicity DNA damage HepG2 WRL68

A review of direct numerical simulations of astrophysical detonations and their implications

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Frontiers of physics 2013年第2期8卷 189-198页

作者： Suzanne T. Parete-Koon Christopher R. Smith Thomas L. Papatheodore O. E. Bronson messer National Center for Computational Sciences Oak Ridge National Laboratory Oak Ridge USA TN 37831-6354 Department of Physics and Astronomy University of Tennessee KnoxvilleUSA TN 37996-1200

Multi-dimensional direct numerical simulations （DNS） of astrophysical detonations in degenerate matter have revealed that the nuclear burning is typically characterized by cellular structure caused by transverse instabilities in the detonation front. Type Ia supernova modelers often use one- dimensional DNS of detonations as inputs or constraints for their whole star simulations. While these one-dimensional studies are useful tools, the true nature of the detonation is multi-dimensional. The multi-dimensional structure of the burning influences the speed, stability, and the composition of the detonation and its burning products, and therefore, could have an impact on the spectra of Type Ia supernovae. Considerable effort has been expended modeling Type Ia supernovae at densities above 1 ~ 107 ***-3 where the complexities of turbulent burning dominate the flame propagation. How- ever, most full star models turn the nuclear burning schemes off when the density falls below 1 ~ 107 ***-3 and distributed burning begins. The deflagration to detonation transition （DDT） is believed to occur at just these densities and consequently they are the densities important for studying the properties of the subsequent detonation. This work will review the status of DNS studies of detona- tions and their possible implications for Type Ia supernova models. It will cover the development of Detonation theory from the first simple Chapman-Jouguet （C J） detonation models to the current models based on the time-dependent, compressible, reactive flow Euler equations of fluid dynamics.

关键词： supernova detonations direct numerical simulations

The Crystal structure of Hexakisammonium Diacety loctamoly bdate Tetrahydrate

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Chinese Journal of Structural Chemistry 2000年第3期19卷 191-194页

作者： Wang, S Lin, X Lu, CZ Wu, DM Yang, WB Zhuang, hh Chinese Acad Sci Fujian Inst Res Struct Matter State Key Lab Struct Chem Fuzhou 350002 Peoples R China

The title compound, 〔NH 4〕 6〔(CH 3CO) 2(Mo 8O 28 )〕·4H 2O, was produced from (NH 4) 6〔Mo 7O 24 〕·4H 2O aqueous solution in the presence of N 2H 4·H 2SO 4 and its structure has been deter... 详细信息

The title compound, 〔NH 4〕 6〔(CH 3CO) 2(Mo 8O 28 )〕·4H 2O, was produced from (NH 4) 6〔Mo 7O 24 〕·4H 2O aqueous solution in the presence of N 2H 4·H 2SO 4 and its structure has been determined by X ray single crystal analysis. The crystallographic data: C 4H 38 Mo 8N 6O 34 , M r =1481.92, triclinic, P1, a=8.127(2), b = 10\^373(2), c = 12.383(3) , α=99.51(3), β=105.47(3), γ=112.92(3)°, V=883.0(3) 3, Z=1, D c =2.787g/cm 3, F(000)= 712, μ =2.864 mm -1 , Final R =0.0368 and wR =0.0924 for 2926 reflections with I>2σ(I ). The X ray crystal structure analysis reveals that there is one independent molecule in the unit cell of the title compound which contains one centrosymmetric diacetyloctamolybdate anion, six ammonium cations and four water molecules.

关键词： diacetyloctamolybdate centrosymmetric hexakisammonium