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The properties of a large volume-limited sample of face-on low surface brightness disk galaxies

Research in Astronomy and Astrophysics 2012年第11期12卷 1486-1498页

作者： Guo-Hu Zhong Yan-Chun Liang Feng-Shan Liu francois hammer Karen Disseau Li-Cai Deng National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academyof Sciences Beijing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China GEPI Observatoire de Paris-Meudon 92195 Meudonl France College of Physical Science and Technology Shenyang Normal University Shenyang 110034China Univ Paris Diderot Sorbonne Paris Cit6 GEPI UMR8111 CNRS Observatoire de ParisF-92190 Meudon France

We select a large volume-limited sample of low surface brightness galax- ies （LSBGs, 2021） to investigate in detail their statistical properties and their dif- ferences from high surface brightness galaxies （HSBGs, 3639）. The distributions of stellar masses of LSBGs and HSBGs are nearly the same and they have the same me- dian values. Thus this volume-limited sample has good completeness and is further removed from the effect of stellar masses on their other properties when we compare LSBGs to HSBGs. We found that LSBGs tend to have lower stellar metallicities and lower effective dust attenuations, indicating that they have lower dust than HSBGs. The LSBGs have relatively higher stellar mass-to-light ratios, higher gas fractions, lower star forming rates （SFRs）, and lower specific SFRs than HSBGs. Moreover, with the decreasing surface brightness, gas fraction increases, but the SFRs and spe- cific SFRs decrease rapidly for the sample galaxies. This could mean that the star formation histories between LSBGs and HSBGs are different, and HSBGs may have stronger star forming activities than LSBGs.

关键词： galaxies fundamentalparameters--galaxies general--galaxies statis-tics -- galaxies stellar content

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Relations between stellar mass and electron temperature-based metallicity for star-forming galaxies in a wide mass range

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Research in Astronomy and Astrophysics 2014年第7期14卷 875-890页

作者： Wei-Bin Shi Yan-Chun Liang Xu Shao Xiao-Wei Liu Gang Zhao francois hammer Yong Zhang Hector Flores Gui-Ping Ruan Li Zhou Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment School of Space Science and PhysicsShandong University Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of Sciences University of Chinese Academy of Sciences Kavli Institute for Astronomy and Astrophysics Peking University GEPI Observatoire de Paris-Meudon Department of Physics University of Hong Kong

We select 947 star-forming galaxies from SDSS-DR7 with [O III]λ4363emission lines detected at a signal-to-noise ratio larger than 5σ. Their electron temperatures and direct oxygen abundances are then determined. We compare the results from different methods. t2, the electron temperature in the low ionization region, estimated from t3, that in the high ionization region, is compared using three analysis relations between t2- t3. These show obvious differences, which result in some different ionic oxygen abundances. The results of t3, t2, O＋＋/H＋and O＋/H＋derived by using methods from IRAF and literature are also compared. The ionic abundances O＋＋/H＋are higher than O＋/H＋for most cases. The different oxygen abundances derived from Teand the strong-line ratios show a clear discrepancy, which is more obvious following increasing stellar mass and strong-line ratio R23. The sample of galaxies from SDSS with detected [O III]λ4363 have lower metallicites and higher star formation rates, so they may not be typical representatives of the whole population of galaxies. Adopting data objects from Andrews ＆ Martini, Liang et al. and Lee et al. data, we derive new relations of stellar mass and metallicity for star-forming galaxies in a much wider stellar mass range： from 106 M to 1011 M.

关键词： galaxies: abundances -- galaxies: evolution -- galaxies: ISM -- galax-ies: spiral -- galaxies: starburst -- galaxies: stellar content

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星系金属丰度的研究进展(Ⅰ):定标方法

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天文学进展 2006年第4期24卷 335-361页

作者：梁艳春 hammer francois 邓李才赵刚中国科学院国家天文台 GEPI Observatoire de Paris-Meudon92195 MeudonFrance

金属丰度是表征星系特征的重要参量,对于理解星系的形成与演化具有重要意义。随着观测设备的不断完善与发展,已经获得越来越多的星系(包括近邻星系、中等红移及高红移星系)金属丰度的观测资料。在光致电离模型方面也取得了很大进展．这... 详细信息

金属丰度是表征星系特征的重要参量,对于理解星系的形成与演化具有重要意义。随着观测设备的不断完善与发展,已经获得越来越多的星系(包括近邻星系、中等红移及高红移星系)金属丰度的观测资料。在光致电离模型方面也取得了很大进展．这些对于理解星系中金属及恒星成分的累积历史有非常重要的作用。有多种方法可以用来估计星系的金属丰度(主要是星际介质中气相的O丰度),介绍和评述了估计星系的O丰度的多种方法,包括电子温度的方法、R23方法以及其他一些“强线”比值的方法,并给出了相应的解析公式,同时介绍了电离星云的物理本质及由光致电离模型估计星系金属丰度的方法,还给出了估计星系的C和N元素丰度的方法。

关键词：天体物理学金属丰度综述星系化学演化

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Multiwavelength study of nearly face-on low surface brightness disk galaxies

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Research in Astronomy and Astrophysics 2010年第12期10卷 1223-1241页

作者： Dong Gao Yan-Chun Liang Shun-Fang Liu Guo-Hu Zhong Xiao-Yan Chen Yan-Bin Yang francois hammer Guo-Chao Yang Li-Cai Deng Jing-Yao Hu National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China ycliang @ nao. cas. cn dgao @ nao. cas. cn Key Laboratory of Optical Astronomy National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China Graduate University of Chinese Academy of Sciences Beijing 100049 China GEPI Observatoire de Paris-Meudon 92195 Meudon France Department of Physics Hebei Normal University Shijiazhuang 050016 China

We study the ages of a large sample （1802） of nearly face-on disk low surface brightness galaxies （LSBGs） using the evolutionary population synthesis （EPS） model PEGASE with an exponentially decreasing star formation rate to fit their mul- tiwavelength spectral energy distributions （SEDs） from far-ultraviolet （FUV） to nearinfrared （NIR）. The derived ages of LSBGs are 1-5 Gyr for most of the sample no matter if constant or varying dust extinction is adopted, which are similar to most of the previous studies on smaller samples. This means that these LSBGs formed the majority of their stars quite recently. However, a small part of the sample （~2%-3%） has larger ages of 5-8 Gyr, meaning their major star forming process may have occurred earlier. At the same time, a large sample （5886） of high surface brightness galaxies （HSBGs） are selected and studied using the same method for comparisons. The de- rived ages are 1-5 Gyr for most of the sample （97%） as well. These results probably mean that these LSBGs have not much different star formation histories from their HSBGs counterparts. However, we should notice that the HSBGs are generally about 0.2 Gyr younger, which could mean that the HSBGs may have undergone more recent star forming activities than the LSBGs.

关键词： galaxies: evolution -- galaxies: formation -- galaxies: photometry --galaxies: spiral -- galaxies: statistics -- ultraviolet: galaxies

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星系金属丰度的研究进展(Ⅱ):光度-金属丰度关系

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天文学进展 2007年第1期25卷 22-35页

作者：梁艳春 hammer francois 邓李才赵刚中国科学院国家天文台 GEPI.Observatoire de Paris-Meudon 92195 MeudonFrance

金属丰度与星系光度是星系的重要特征参量,研究它们之间的关系有助于理解星系中恒星质量与金属成分的累积过程。评述了星系的光度-金属丰度关系的最新研究进展,包括对近邻星系、中等红移星系(0．42)的研究结果．由于观测样本跨越较宽的... 详细信息

金属丰度与星系光度是星系的重要特征参量,研究它们之间的关系有助于理解星系中恒星质量与金属成分的累积过程。评述了星系的光度-金属丰度关系的最新研究进展,包括对近邻星系、中等红移星系(0．42)的研究结果．由于观测样本跨越较宽的宇宙学时标,可以由此来探讨这一关系的演化过程,从而帮助理解星系演化的整体图景。

关键词：天体物理学星系综述金属丰度光度-金属丰度关系

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White,everything white?Josef Frank’s Villa Beer(1930)in Vienna,and its materiality in the context of the discourse on‘white cubes’

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Built Heritage 2020年第2期4卷 40-55页

作者： Ivo B.hammer HAWK University of Applied Sciences and Art HildesheimGermany

In 2017 a group of conservators-restorers conducted a conservation-science study of the materials used in the construction of Josef Frank’s main work,the Villa Beer(1930)in Vienna-Hietzing,and of the building’s *** study was an opportunity to find evidence indicating whether the contemporary description of the wall colour as a non-colour white corresponded to physical *** notion‘Weiss,alles Weiss’(‘white,everything white’),celebrated as‘an expression of values and of the times’(Hammann,1930),will be identified as a cultural construct that stands in contradiction to the actual materiality of the buildings of the *** must rewrite the colour history of Modern Movement ***‘White Cubes’were never white.

关键词： Modern movement architecture Josef Frank Villa Beer Materiality White Conservation-restoration Conservation-science study White cubes Le Corbusier

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Evaluation of strategies for the subsequent use of CO_(2)

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Frontiers of Chemical Science and Engineering 2010年第2期4卷 172-183页

作者： Marc SCHAEFER Frank BEHRENDT Thomas hammer Berlin Institute of Technology Institute for Energy Process Engineering and Conversion Technologies for Renewable EnergiesBerlin 10623Germany Siemens AG Corporate TechnologyCT PS 591052 ErlangenGermany

If substantial amounts of CO_(2),which according to actual scenarios may in the future be captured from industrial processes and power generation,shall be utilized effectively,scalable energy efficient technologies will be ***,a survey was performed to assess a large variety of applications utilizing CO_(2) chemically(e.g.,production of synthesis-gas,methanol synthesis),biologically(e.g.,CO_(2) as fertilizer in green houses,production of algae),or physically(enhancement of fossil fuel recovery,use as refrigerant).For each of the processes,material and energy balances were set *** with pure CO_(2) at standard conditions,expenditure for transport and further process specific treatment were *** on these calculations,the avoidance of greenhouse gas emissions by applying the discussed technologies was *** on the currently available technologies,applications for enhanced fossil fuel recovery turn out to be most attractive regarding the potential of utilizing large quantities of CO_(2)(total capacity>1000 Gt CO_(2))and producing significant amounts of marketable products on one hand and having good energy and material balances on the other hand(t_(CO_(2)-emitted)/t_(CO_(2)-utilized)0.34).Biological processes such as CO_(2) fixation using microalgae look attractive as long as energy and CO_(2) balance are ***,the development of effective photobioreactors for growing algae with low requirements for footprint area is a challenge.

关键词： CO_(2) utilization survey energy balances synthesis-gas green houses micro-algae fossil fuel recovery

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作者： Chris hammer.

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The proton radius:from a puzzle to precision

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Science Bulletin 2020年第4期65卷 257-258页

作者： Hans-Werner hammer Ulf-GMeiBner Institut für Kernphysik Technische Universitat Darmstadt64289 DarmstadtGermany ExtreMe Matter Institute EMMI GSI Helmholtzzentrum für Schwerionenforschung GmbH64291 DarmstadtGermany Helmholtz Institut für Strahlen-und Kernphysik and Bethe Center for Theoretical Physics Universitat BonnD-53115 BonnGermany Institute for Advanced Simulation and Institut für Kernphysik Forschungszentrum JülichD-52425 JülichGermany Tbilisi State University 0186 TbilisiGeorgia

The proton charge radius rP is a fundamental quantity in particle physics,as it challenges our understanding of the so successful Standard Model in the non-perturbative regime of the strong *** is defined by the slope of the proton charge form factor GE p etT at zero momentum transfer,with t the invariant four-momentum transfer *** proton charge radius was first indirectly measured in the Nobel prize winning electron scattering experiments by Hofstadter et al.[1,2],who fitted the form factor data with a dipole form and extracted the radius from the slope of the dipole.

关键词：精准测量

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Evaluation of adenosine triphosphate bioluminescence-based system in rooms occupied by patients with methicillin resistant Staphylococcus

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Infectious Medicine 2022年第3期1卷 217-220页

作者： Anna Montgomery Kimberly hammer Dubert Guerrero Tze Shien Lo Department of Research San Francisco VA Medical CenterSan FranciscoCAUSA Department of Medicine University of California San FranciscoSan FranciscoCAUSA Department of Medicine University of North Dakota School of Medicine and Health SciencesGrand ForksNDUSA Department of Infection Prevention Fargo VA Healthcare SystemFargoNDUSA Department of Infection Prevention Sanford HealthFargoNDUSA

Background:Adenosine triphosphate(ATP)-based monitoring systems can detect the amount of organic matter that remains on hospital surfaces after *** evaluated an ATP-based monitoring system in assessing con-tamination of high touched objects in rooms occupied by patients on methicillin resistant *** ***:We compared the ATP to standard aerobic cultures as well as to gloved hand culture to predict risk of healthcare-worker hand ***:More than a third of high touch object surfaces were measured unclean with ATP yet only reflects about 5%chance of contaminating healthcare-workers’***:Our study emphasizes the shortcomings of using the ATP system even in pathogen specific environ-ment such as surfaces in methicillin resistant *** rooms.

关键词： Environment Healthcare-associated infections Hand hygiene Infection prevention Infection control MRS

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