|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | 磁赤铁矿的几种类型与特点分析显示文摘随着环境磁学的广泛开展和应用,最近20年来磁赤铁矿(γ-Fe2O3)被人们所日益熟悉.现在它已经被发现是一种地表十分常见的矿物,与磁铁矿常常相伴随,是氧化透水通气环境的很好指示矿物.它也是制造音乐和录像磁带的重要磁性材料,在工业有很广泛的用途.磁赤铁矿的人工合成一般由磁铁矿通过在低于300℃的氧化环境中加热几个小时甚至几天时间来形成.它受热不稳定而产生化学变化的磁学性质是其重要特点,即加热到250℃之后该矿物一般就会被不同程度转变成为赤铁矿.因此实际上无法测量其居里点.后来对人工合成磁赤铁矿样品研究进一步发现,该矿物受热可以部分热稳定,居里温度约为645℃.本文通过不同粒度人工磁铁矿系列样品进行热磁测量实验时发现,超细粒级(假单畴(PSD)和多畴(MD)细粒)磁铁矿在快速加热过程中,形成了完全热稳定的磁赤铁矿.而且,用同样的样品在另外加热炉中快速加热到700℃高温,并且在该温度停留10min,然后冷却下来,也可以达到相同的效果.即由此两个过程形成的磁赤铁矿,再从室温加到700℃的居里温度测量过程几乎达到百分之百可逆,即完全对热稳定性特点.我们用X衍射和穆斯堡尔谱技术来鉴定和确认加热前的磁铁矿和快速加热形成的磁赤铁矿(和赤铁矿),并且比较其磁铁矿的磁滞迴线、高温磁化强度、低温热退磁和低温磁化率特性,结果表明,这种过程通过超细磁铁矿加热快速氧化形成完全可逆具有热稳定性质的磁赤铁矿,可能暗示着在某些加热环境形成的磁赤铁矿也可能携带热剩磁.根据磁赤铁矿是否受热不稳定及其表现形式,将它详细分成4种类型探讨分析.受热后部分稳定和完全稳定的磁赤铁矿应当具备携带热剩磁的能力.人工合成磁赤铁矿的温度与其反应时间可能有个互补关系.磁赤铁受热后稳定与否可能与多种因素有关,如受纯度大小、受热温度高低和时间长短等影响,粒度大小可能也是重要因素之一.磁赤铁矿可能如同磁铁矿,也有不同粒级超顺磁(SP)、单畴(SD)和MD对应着不同的磁学特点.细粒PSD氧化的人工磁铁矿在低温磁学测量显示为Verwey转换被'抑制'的现象,其根本原因可能是,氧化后磁铁矿的内核直径实际上已经达到或者接近该矿物的SD粒径,所以它的Verwey转换显得被'抑制'. | 刘秀铭 John SHAW 蒋建中 Jan BLOEMENDAL Paul HESSE Tim ROLPH 毛学刚 | 2010 | 中国科学:地球科学2010，40，5： | 20 |
| 2 | Analysis on variety and characteristics of maghemite显示文摘Maghemite (γ-Fe2O3) is a very common mineral at the earth’s surface and also an important material for making music and video tapes. Maghemite is usually synthesized from magnetite under oxidizing conditions after a few hours or a few days below a temperature of 300°C. The magnetic property of thermal instability and the chemical action after heating is an important character for maghemite. That is, it will become hematite in certain proportion after being heated above 250°C. Maghemite is therefore actually unable to have its Curie temperature measured. But late using synthetic sample, maghemite was further found partially thermal stable with a measurable Curie temperature ~645°C. During our thermally magnetic experiments for a set of synthetic magnetite, we found that extra fined grain size (pseudo single domain (PSD) and small multi-domain (MD), mainly 1-10 μm) magnetite was formed to a completely thermally stable maghemite. This maghemite can also be produced by heating the same powder up to 700°C in an oven and keeping this temperature for 10 min, then cooling it down. When the generated maghemite by these two ways is heated from room temperature to 700°C, it shows almost fully reversible, or thermally stable. We used X-ray powder diffraction and Mssbauer spectroscopy to confirm the identity of this maghemite and compared its magnetic hysteresis, high temperature magnetization, low temperature thermal demagnetization, and low temperature susceptibility with those of the original preheated magnetite. Such quickly oxidized maghemite by heating to high temperature implies some types of maghemite formed in certain natural condition can carry a thermal remnant magnetization (TRM). Four types of maghemite were characterized and discussed according to their thermal stability. Among them, partially stable and fully thermally stable maghemite after heating should possess capability of carrying TRM. There is possibly a compensation of synthetizing maghemite between heating temperature and heating duration. The thermal stability of maghemite may be affected by a few factors, such as its purity (stoichiometry), heating temperature and duration. The grain size may be one of important factors. Maghemite might be similar to magnetite, having various magnetic properties corresponding to its grain size categories such as superparamagnetic (SP), single domain (SD) and MD. Low temperature measurement for PSD fine grain of synthetic magnetite shows a phenomenon of Verwey transition 'suppressed', its fundamental causes could be that the core diameter of oxidized magnetite is actually reach or approach SD size, so that its Verwey transition is shown 'suppressed'. | SHAW John BLOEMENDAL Jan HESSE Paul ROLPH Tim | 2010 | Science China Earth Sciences2010，53，8： | 3 |
| 3 | Customer loyalty in e-commerce: an exploration of its antecedents and consequences显示文摘 | Srini S. Srinivasan Rolph Anderson Kishore Ponnavolu | 2002 | Journal of Retailing2002，，1： | 3 |
| 4 | E‐satisfaction and e‐loyalty: A contingency framework显示文摘 | Rolph E.Anderson Srini S.Srinivasan | 2003 | Mark2003，，2： | 2 |
| 5 | B/M极性转换过程与虚磁极转移路径显示文摘利用超导磁力仪对西峰黄土剖面记录的布容/松山(B/M)地磁极性转换过程的高分辨率研究表明,B/M极性转换经历了由负极性到正极性的五次反复倒转;转换过程中地磁场的强度衰减到正常值的约30%,场强的衰减是极性转换的前奏,而地磁场方向完全倒转后的场强恢复,是转换的最后一幕;极性转换所需的时间约2万年,从场强的开始衰减到反向恢复则需要更长的时间;极性转换的虚地磁极(VGP)转移路径大多连续,并落于一定的径度带内,包括美洲径度带、大西洋径度带和非洲径度带。西峰剖面记录的B/M转换VGP路径并未落入美洲和印度洋这两个高密径度带内。 | 孙东怀 John Shaw 郑洪波 马醒华 Tim Rolph | 1994 | 自然科学进展(国家重点实验室通讯)1994，4，4： | 2 |
| 6 | An efficient algorithm for analysis of nonlinear heat transfer with phase changes显示文摘 | Donald Rolph W Bathe K J | 1982 | International Journal for Numerical Methods in Engineering1982，18，： | 2 |
| 7 | Molecular identification of bacteria on the tongue dorsum of subjects with and without halitosis显示文摘 | Riggio MP Lennon A Rolph HJ | 2008 | Oral Diseases2008，14，3： | 1 |
| 8 | MHC class Ia-restricted T cells partially account for beta2-microglobulin-dependent resistance to Mycobacterium tuberculosis显示文摘 | Raupach B Kobernick HH | 2001 | Eur J Immunol2001，31，6： | 1 |
| 9 | Incluetion of protective immunity in cattle against in fection with Fasciola hepatica by vaccination with cathepsin L proteinases and with hemoglobin显示文摘 | DALTON J P MCGONIGLE S ROLPH T P | 1999 | Am Soc Microbiol1999，64，： | 1 |
| 10 | Epithelial invasion and cell lysis by virulent strains of Streptococcus suis is enhanced by the presence of suilysin显示文摘 | Norton P Rolph C Ward P | 1999 | FEMS Immunol Med Microbiol1999，26，1： | 1 |
| 11 | The effect of the beta-adrenergic agonist salbutamol on meat quality in pigs 显示文摘 | Warriss PD Kestin SC Rolph T P | 1990 | J Anim Sci1990，68，： | 1 |
| 12 | Epithelial invasion and cell lysis by virulent strains of Streptococcus suis is enhanced by the presence of suilysin显示文摘 | Norton P M Rolph C Ward P N | 1999 | FEMS Immunol Med Microbiol1999，26，1： | 1 |
| 13 | Granulocyte-macrophage colony-stimulating factor is required for bronchial eosinophilia in a murine model of allergic airway inflammation显示文摘 | Su YC Rolph MS Hansbro NG | 2008 | J Immunol2008，180，4： | 1 |
| 14 | A Theory of Excise Subsidies显示文摘 | Rolph E R | 1952 | The American Economic Review1952，42，4： | 1 |
| 15 | Epithelial invasion and cell lysis by virulent strains of Streptococcus suis is enhanced by the presence of suilysin显示文摘 | Pamela M Norton Charlotte Rolph Philip N Ward Robert W Bentley James A Leigh | 1999 | FEMS Immunology and Medical Microbiology1999，，1： | 1 |
| 16 | 《社会语言学》评介显示文摘1.引言
Ralph Fasold(1990,1999)所著<社会语言学>(The Sociolinguistics of Language)一书,是Basil Blackwell出版社'社会中的语言'(Language in Society)系列丛书中的一种.这套丛书从八十年代起开始推出,种类已由最初的14种增加到目前的28种.总编虽然仍为Peter Trudgill,丛书顾问班子却已由最初的两名,增至现在的四位.他们分别是:Ralph Fasold,William Labov,J.K.Chambers,以及Lesley Milroy. | Rolph Fasold 杨永林 | 2002 | 当代语言学2002，4，4： | 1 |
| 17 | MIP-1alpha,MIP-1beta,RANTES,and ATAC/lymphotactin function together with IFN-gamma as type 1 cytokines显示文摘 | Dorner BG Scheffold A Rolph MS Huser MB Kaufmann SH Radbruch A Flesch IE Kroczek RA | 2002 | Proc Natl Acad Sci USA2002，99，9： | 1 |
| 18 | MIP-1α,MIP-1β,RANTES,and ATAC/lymphotactin function together with IFN-γ as type 1 cytokines显示文摘 | Dorner BG Scheffold A Rolph MS | 2002 | Proc Natl Acad Sci USA2002，99，9： | 1 |
| 19 | Induction of protective immunity in cattle against infection with Fasciola hepatica by Vaccination with cathepsim L proteinases and hemoglobin显示文摘 | Dalton J P Mc Gonigle S Rolph T P | 1997 | Infec and Immun1997，64，： | 1 |
| 20 | Production of the long pentraxin 3 PTX3 in advanced atherosclerotic plaques显示文摘 | Rolph MS Zimmer S Bottazzi B | 2002 | Arterioscler Thromb Vasc Biol2002，22，5： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员