这项工作是由美国航空航天局授予NNX11AC68G和华盛顿卡内基研究所的支持。我感谢张驰为他协助收集数据。我还要感谢解剖学沙哈尔和Valerie Hillgren这个手稿的有益的评论。

1。准备原料和样品室<ol><li>制备两种类型的起始原料，天然硅酸盐橄榄石和金属铁粉末与10重量％的硫（金属/硅酸盐比例范围从4至30重量％），用于模拟中的固体硅酸盐基质的液体铁合金渗滤（1）的混合物在一个小的行星体，和（2）的均匀的微细接地纯铁和铁的硫化物，用于确定所述行星内芯结晶混合物的初始芯形成。 </li><li>磨下乙醇的起始材料，以精细的混合粉末在玛瑙研钵中一小时，并在100℃下干燥。 </li><li>加载的起始材料为烧结的MgO或Al 2 O 3的胶囊剂（通常为1.5毫米的直径和长度为1.5），然后将其放置在高压电池组件，用于多砧实验。 </li><li>加载铁的FeS的混合物进入一个小样本室（通常为100微米，直径25＆＃181;米厚）钻一个preindented铼垫片激光加热实验的钻石砧细胞。夹着其作为热绝缘体的NaCl层之间的铁的FeS的混合物。 </li></ol> 2。高压和高温实验中的多顶砧高压装置<ol><li>多砧高压电池组件由一个MgO的八面体作为压力介质，ZrO 2的套筒作为热绝缘体，和一个圆柱形铼或石墨加热器。加热器内的样品胶囊配合。 A型-C热电偶插入到样品室，以确定样品的温度。 </li><li>将高压组件中用于加压的多砧高压装置。 </li><li>多顶砧高压装置包括一个1500吨的液压机，压力模块，它包含一个固定环与六可拆卸推楔形成立方腔的中心15。立方腔ħouses 8碳化钨立方体截断角落。截短的立方体，它收敛于八面体单元组件，彼此由可压缩垫圈隔开。液压油缸由一个两阶段的砧座结构。 图1示出了用于多砧实验的实验步骤，有效地将力传递到样品集。 </li><li>样品加压到2-27 GPA在室温下基于固定点压力校准曲线16，然后将其加热到试验温度高达2300℃下通过电阻加热之间的目标压力;维持实验在恒定温度对于实验的持续时间;和关闭到样品骤冷至室温，在实验结束时的功率。 </li><li>释放压力缓慢通过打开液压油阀和恢复实验费。 </li></ol> 3。激光加热实验中钻石砧细胞<ol><li> 2宝石级单晶金刚石砧（各约0.25克拉）之间产生的压力在金刚石压腔。我们使用对称金刚石压腔驱动完全对齐相对砧座与活塞 - 气缸系统。该细胞能够产生对应于地球的核心17的压力条件下的压力。高温是通过激光加热金刚石压腔来实现。我们使用一个系统在超前光子源（APS），它是基于一个双面激光加热技术，由两个光纤激光器，光学系统，以从两侧加热样品，和2分光​​系统两侧的温度测量18。该系统被设计来产 ​​生一个大的加热斑点（直径25μm）时，在金刚石压腔径向和轴向最小化样品的温度梯度，并最大限度地提高加热稳定性， 图2示出了示意S中的实验配置为激光加热试验中金刚石砧细胞用激光加热斑点的图像的。 </li><li>对齐金刚石砧与300微米culets并从250微米的初始厚度preindent铼垫圈的厚度为30微米。 </li><li>钻在preindented垫圈的孔的直径为120微米的中心，并加载在样品中的孔。 </li><li>样品加压到在室温下的目标压力，然后通过提高激光功率，同时考虑温度测量和原位 X射线衍射测量在同步加速器设施加热样品。 </li><li>关闭激光功率，以便淬灭样品，当部分熔融是通过热辐射和来自衍射图案的变化来检测。 </li><li>恢复易地表征加热样品。 </li></ol> 4。样品回收率及分析<ol><li>莫UNT检索多砧样品中的环氧树脂，并使用一套金刚石粉末粒度为150微米到0.25微米的抛光表面。 </li><li>碳涂层的样品表面并将其装载到一个蔡司御夫座FIB / SEM横梁仪器（ 图3A）进行分析的样品室。 </li><li>样品对准以5mm（ 图3B）的工作距离的点重合的FIB和SEM，然后premill样品暴露的15×20×20微米3（ 图3C）的体积。 </li><li>使用该切片与视图函数的蔡司御夫FIB / SEM仪（自动记录的一系列图像的离子束研磨具有约35nm的典型图像的分辨率后）采取的SEM图像，在25纳米的间隔。 </li><li>输入的图像数据文件到一个可视化软件和重建三维图像可视化的熔体分配和连通的淬火样品中（ 图3中D）。 </li></ol>

<ol>
	<li>Wetherill, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+the+terrestrial+planets.">Formation of the terrestrial planets.</a> Annual Review of Astronomy and Astrophysics. 18, 77-113 (1980).</li><li>Chambers, J. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Planetary+accretion+in+the+inner+Solar+System.">Planetary accretion in the inner Solar System.</a> Earth and Planetary Science Letters. 223, 241-252 (2004).</li><li>Greenwood, R. C., Franchi, I. A., Jambon, A., Buchanan, P. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Widespread+magma+oceans+on+asteroidal+bodies+in+the+early+Solar+System.">Widespread magma oceans on asteroidal bodies in the early Solar System.</a> Nature. 435, 916-918 (2005).</li><li>Mann, U., Frost, D. J., Rubie, D. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+wetting+ability+of+Si-bearing+liquid+Fe-alloys+in+a+solid+silicate+matrix-percolation+during+core+formation+under+reducing+conditions.">The wetting ability of Si-bearing liquid Fe-alloys in a solid silicate matrix-percolation during core formation under reducing conditions.</a> Physics of the Earth and Planetary Interiors. 167 (1-2), 1-7 (2008).</li><li>Terasaki, H., Frost, D. J., Rubie, D. C., &amp;Langenhorst, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Percolative+core+formation+in+planetesimals.">Percolative core formation in planetesimals.</a> Earth and Planetary Science Letters. 273, 132-137 (2008).</li><li>Walte, N. P., Becker, J. K., Bons, P. D., Rubie, D. C., Frost, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Liquid-distribution+and+attainment+of+textural+equilibrium+in+a+partially-molten+crystalline+system+with+a+high-dihedral-angle+liquid+phase.">Liquid-distribution and attainment of textural equilibrium in a partially-molten crystalline system with a high-dihedral-angle liquid phase.</a> Earth and Planetary Science Letters. 262, 517-532 (2007).</li><li>Terasaki, H., Frost, D. J., Rubie, D. C., Langenhorst, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interconnectivity+of+Fe-O-S+liquid+in+polycrystalline+silicate+perovskite+at+lower+mantle+conditions.">Interconnectivity of Fe-O-S liquid in polycrystalline silicate perovskite at lower mantle conditions.</a> Physics of Earth and Planetary Interiors. 161, 170-176 (2007).</li><li>Halliday, A. N., Wood, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+did+Earth+accrete?.">How did Earth accrete?.</a> Science. 325, 44-45 (2009).</li><li>Yoder, C. F., Konopliv, A. S., Yuan, D. N., Standish, E. M., Folkner, W. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fluid+core+size+of+Mars+from+detection+of+the+solar+tide.">Fluid core size of Mars from detection of the solar tide.</a> Science. 300, 299-303 (2003).</li><li>Margot, J. L., Peale, S. J., Jurgens, R. F., Slade, M. A., Holin, I. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Large+longitude+libration+of+Mercury+reveals+a+molten+core.">Large longitude libration of Mercury reveals a molten core.</a> Science. 316, 710-714 (2007).</li><li>Fei, Y., Bertka, C. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+interior+of+Mars.">The interior of Mars.</a> Science. 308, 1120-1121 (2005).</li><li>Williams, J. -. P., Nimmo, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thermal+evolution+of+the+Martian+core:+Implications+for+an+early+dynamo.">Thermal evolution of the Martian core: Implications for an early dynamo.</a> Geology. 32, 97-100 (2004).</li><li>Smith, D. E., Zuber, M. T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gravity+field+and+internal+structure+of+Mercury+from+MESSENGER.">Gravity field and internal structure of Mercury from MESSENGER.</a> Science. 336, 214-217 (2012).</li><li>Weber, R. C., Lin, P. -. Y., Garnero, E. J., Williams, Q., Lognonn&#233;, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Seismic+detection+of+the+Lunar+core.">Seismic detection of the Lunar core.</a> Science. 331, 309-312 (2011).</li><li>Li, J., Fei, Y., Carlson, R. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+constraints+on+core+composition.">Experimental constraints on core composition.</a> Geochemistry of the Mantle and Core. , 521-546 (2007).</li><li>Bertka, C. M., Fei, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mineralogy+of+the+Martian+interior+up+to+core-mantle+boundary+pressures.">Mineralogy of the Martian interior up to core-mantle boundary pressures.</a> Journal of Geophysical Research. 102, 5251-5264 (1997).</li><li>Tateno, S., Hirose, K., Ohishi, Y., Tatsumi, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+structure+of+iron+in+Earth's+inner+core.">The structure of iron in Earth's inner core.</a> Science. 330, 359-361 (2010).</li><li>Prakapenka, V. B., Kubo, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advanced+flat+top+laser+heating+system+for+high+pressure+research+at+GSECARS:+application+to+the+melting+behavior+of+germanium.">Advanced flat top laser heating system for high pressure research at GSECARS: application to the melting behavior of germanium.</a> High Pressure Research. 28, 225-235 (2008).</li><li>Minarik, W. G., Ryerson, F. J., Watson, E. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Textural+entrapment+of+core-forming+melts.">Textural entrapment of core-forming melts.</a> Science. 272, 530-533 (1996).</li><li>Terasaki, H., Frost, D. J., Rubie, D. C., Langenhorst, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+oxygen+and+sulphur+on+the+dihedral+angle+between+Fe-O-S+melt+and+silicate+minerals+at+high+pressure:+Implications+for+Martian+core+formation.">The effect of oxygen and sulphur on the dihedral angle between Fe-O-S melt and silicate minerals at high pressure: Implications for Martian core formation.</a> Earth and Planetary Science Letters. 232, 379-392 (2005).</li><li>Fei, Y., Bertka, C. M., Finger, L. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-pressure+iron-sulfur+compound,+Fe3S2,+and+melting+relations+in+the+system+Fe-FeS+at+high+pressure.">High-pressure iron-sulfur compound, Fe3S2, and melting relations in the system Fe-FeS at high pressure.</a> Science. 275, 1621-1623 (1997).</li><li>Fei, Y., Li, J., Bertka, C. M., Prewitt, C. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+type+and+bulk+modulus+of+Fe3S,+a+new+iron-sulfur+compound.">Structure type and bulk modulus of Fe3S, a new iron-sulfur compound.</a> American Mineralogist. 85, 1830-1833 (2000).</li><li>Li, J., Fei, Y., Mao, H. K., Hirose, K., Shieh, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sulfur+in+the+Earth's+inner+core.">Sulfur in the Earth's inner core.</a> Earth and Planetary Science Letters. 193, 509-514 (2001).</li><li>Chen, B., Li, J., Hauck, S. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-ideal+liquidus+curve+in+the+Fe-S+system+and+Mercury's+snowing+core.">Non-ideal liquidus curve in the Fe-S system and Mercury's snowing core.</a> Geophysical Research Letter. 35, L07201 (2008).</li><li>Buono, A. S., Walker, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Fe-rich+liquidus+in+the+Fe-FeS+system+from+1+bar+to+10+GPa.">The Fe-rich liquidus in the Fe-FeS system from 1 bar to 10 GPa.</a> GeochimicaCosmochimicaActa. 75, 2072-2087 (2011).</li><li>Ito, E., Yamazaki, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Pressure+generation+and+investigation+of+the+post-perovskite+transformation+in+MgGeO3by+squeezing+the+Kawai-cell+equipped+with+sintered+diamond+anvils.">Pressure generation and investigation of the post-perovskite transformation in MgGeO3by squeezing the Kawai-cell equipped with sintered diamond anvils.</a> Earth and Planetary Science Letters. 293 (1-2), 84-89 (2010).</li><li>Roberts, J. J., Kinney, J. H., Siebert, J., Ryerson, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fe-Ni-S+melt+permeability+in+olivine:+implications+for+planetary+core+formation.">Fe-Ni-S melt permeability in olivine: implications for planetary core formation.</a> Geophysical Research Letter. 34, L14306 (2007).</li><li>Wang, Y., Lesher, C., Fiquet, G., Rivers, M., Nishiyama, N., Siebert, J., Roberts, J., Morard, G., Gaudio, S., Clark, A., Watson, H., Menguy, N., Guyot, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In-situ+high+P,+T+X-ray+microtomographic+imaging+during+large+deformation:+a+newtechnique+for+studying+mechanical+behavior+of+multi-phase+composites.">In-situ high P, T X-ray microtomographic imaging during large deformation: a newtechnique for studying mechanical behavior of multi-phase composites.</a> Geosphere. 7, 40-45 (2011).</li><li>Watson, H. C., Roberts, J. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Connectivity+of+core+forming+melts:+Experimental+constraints+from+electrical+conductivity+and+X-ray+tomography.">Connectivity of core forming melts: Experimental constraints from electrical conductivity and X-ray tomography.</a> Physics of Earth and Planetary Interiors. 186, 172-182 (2011).</li><li>Fei, Y., Ricolleau, A., Frank, M., Mibe, K., Shen, G., Prakapenka, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Toward+an+internally+consistent+pressure+scale.">Toward an internally consistent pressure scale.</a> Proc. Natl. Acad. Sci. U.S.A. 104, 9182-9186 (2007).</li></ol>

没有利益冲突声明。

该技术的多砧实验已经非常成熟，产生稳定的压力和温度下的运行时间较长，并产生比较大的样品体积。它是一个强有力的工具来模拟行星的内部过程，特别是对于实验，如熔体渗透，需要一定的样品体积。该限制是可以达到的最大压力可达27 GPA与碳化钨（WC）砧，达到火星和水星的核心压力，但太低的压力而到达地球和金星的核心。可达到的最大压力可以通过使用膨胀烧结金刚石砧为26?...

类地行星，如地球，金星，火星和水星是有区别的行星齿轮机构组成的硅酸盐地幔和一个金属芯。现代化的行星形成模型表明，类地行星是从公里大小或更大的行星通过引力相互作用1-2月增长到火星大小的行星胚胎的碰撞形成的。该行星被容易区分已经一次的金属铁的合金达到了来自诸如短命的同位素如26 Al和60的Fe，冲击放射性衰变由于加热熔化温度和势能3的释放。重要的是要了解早期分化过程中通过硅酸盐基质如何液态金属渗出是很重要的。 行星分化可以进行通过高效液 - 液分离，或由液态金属中的固体硅酸盐基质渗滤，这取决于的大小与行星机构的内部温度。液态金属中的固体硅酸盐基质的渗滤很可能在初始分化的主导过程时的温度不高到足以在整个行星体融化。渗滤的效率依赖于二面角，通过固 - 固和固 - 液界面的界面能来确定。我们可以通过在铁合金和硅酸酯的混合物进行高压和高温实验在实验室中模拟这种过程。最近的研究4-7已经调查液体铁合金中的固体硅酸盐基质在高温高压下的润湿能力。他们用传统的方法来测量的淬灭液体和金属硅酸盐颗粒在抛光横截面之间明显的二面角的相对频率分布测定的真实二面角。传统的方法产生比较大的UNCertainties在所测量的二面角和根据采样的统计数据可能的偏差。在这里，我们提出了一种新的成像技术，通过FIB铣削和高分辨率场发射扫描电镜成像的组合形象化液态金属的硅酸盐基质分布在三维（3D）。新的成像技术提供了精确测定的二面角和液相的体积分数和连接的定量度量。 形成在相对 ​​短的时间（&lt;亿年）8地核，想必在液体状态在其早期历史。火星和水星也有基于来自火星环球探测无线电跟踪数据9和雷达的散斑图案绑在行星旋转10，分别为太阳能潮汐形变液体内核。热演化模型和核心材料的高压熔融实验进一步支持液体火星核心11-12。最近信使号飞船的数据提供了水星13的液芯的其他证据。即使是小月亮有可能根据最近的阿波罗月球地震14再分析小液芯。液态行星内核具有高吸积能量一致的行星形成的早期阶段。随后的冷却，会生成一些行星的固体内核的。地震资料显示，地球由一个液态外核和固态内核。内芯的形成具有核心由热合力对流和地球的磁场产生驱动的动力学具有重要意义。 内芯的凝固是由芯材料的熔融温度和芯部的热演化控制。芯形成地行星共享类似增生路径和芯的化学组成被认为是到bË占主导地位的铁，约10％重量轻元素，如硫（S），硅（Si），氧（O），碳（C）和氢（H）15。关键是要在相关的芯，如Fe-硫化亚铁，铁碳，铁的FeO，铁 - FEH，和Fe-FeSiat高压系统的熔化关系的知识，为了理解的组成行星内核。在这个研究中，我们将展示在多砧装置和金刚石砧细胞进行的实验中，模仿行星内核的条件。该实验提供了有关固态和液态金属之间的结晶序列和元件的分区信息，从而导致对于所述内芯和结晶的结晶内芯和液体从芯之间的光元件的分布的要求，更好地理解。为了延长熔的关系，以非常高的压力，我们已经开发了新的技术来分析从激光加热金刚石 - 一个恢复的淬火样品NVIL细胞实验。随着激光光斑加热精密FIB铣削，我们测定熔点使用影像与高分辨率扫描电镜和在亚微米的空间分辨率硅漂移探测器定量化学分析淬火结构的标准。 这里，我们概述了两组实验由金属的渗滤以模仿行星芯形成过程中的早期增生和内芯结晶由随后的冷却熔体在硅酸盐基质。仿真的目的是行星核心的进化过程中，了解两个重要的过程。

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			<td class="xl63" height="43" style="height:32.25pt;width:66pt" width="88">Multi-anvil apparatus</td>
			<td class="xl63" style="border-left:none;width:66pt" width="88">Geophysical Lab</td>
			<td class="xl63" style="border-left:none;width:66pt" width="88">Home Builder</td>
			<td class="xl63" style="border-left:none;width:66pt" width="88"> </td>
		</tr>
		<tr height="43" style="height:32.25pt">
			<td class="xl63" height="43" style="height:32.25pt;border-top:none;
 width:66pt" width="88">Diamond-anvil cell</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">Geophysical Lab</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">Home Builder</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88"> </td>
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		<tr height="64" style="height:48.0pt">
			<td class="xl63" height="64" style="height:48.0pt;border-top:none;
 width:66pt" width="88">Laser-heating system</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">APS GSECARS</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">Designed by beamline staff</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88"> Public beamline</td>
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			<td class="xl63" height="43" style="height:32.25pt;border-top:none;
 width:66pt" width="88">FIB/SEM Crossbeam</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">Carl Zeiss Ltd.</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">Auriga</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88"> </td>
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			<td class="xl63" height="64" style="height:48.0pt;border-top:none;
 width:66pt" width="88">Avizo 3D software</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">VSG</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88">Fire for materials science</td>
			<td class="xl63" style="border-top:none;border-left:none;width:66pt" width="88"> </td>
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simulation of the planetary interior differentiation processes in the laboratory

一种行星内部是高压和高温条件下，它具有层状结构。有迹象表明，导致了层状结构的两个重要的过程，（1）渗透液体金属在通过行星分化的固体硅酸盐基质，和（2）的内芯结晶通过随后行星冷却。我们进行高压和高温实验在实验室中模拟两个进程。渗流行星核心的形成取决于熔渗漉，这是由二面角（润湿）角控制的效率。渗滤模拟包括在高压下与靶温度下的铁 - 硫合金熔融将样品加热而保持硅酸盐固体，然后确定真实的二面角，以评估在通过3D可视化的结晶基质的液体迁移的样式。 3D体积呈现是通过用聚焦离子束（FIB）和钽切片回收的样品来实现每个切片与FIB / SEM横梁乐器之王SEM图像。第二组实验的目的是了解液体外芯和通过确定在高压的熔融温度和元件分隔实心内芯之间的内芯结晶和元素分布。熔点实验均在多砧装置进行多达27 GPa和延伸到与激光加热金刚石砧细胞更高的压力。我们已经开发的技术来恢复小加热样品经精密FIB铣削和获得激光加热点，显示融化的质地在高压下的高清晰度图像。通过分析共存的液相和固相的化学组成中，我们精确地确定液相线曲线，提供了必要的数据，以便了解内芯的结晶过程。

我们已经进行了一系列的使用圣卡洛斯橄榄石和铁的FeS金属合金具有不同的金属硅酸盐的比例的混合物的实验中，作为起始原料。金属中的S含量为10重量％S在这里，我们从显示在6 GPa和1800℃进行高压实验的一些有代表性的结果，利用良好校准的多砧组件15。在实验条件下，铁 - 硫化亚铁金属合金完全熔化和硅酸盐（圣卡洛斯橄榄石）保持结晶。该实验的目的是研究如何液态金属会通过渗?...

Watch this Scientific Journal Video about Simulation of the Planetary Interior Differentiation Processes in the Laboratory at JoVE.com

Simulation of the Planetary Interior Differentiation Processes in the Laboratory

这里所描述的高压和高温实验模拟地球内部分化过程。该过程是由高分辨率三维成像和定量化学分析和可视化更好地理解。

模拟行星内部分化过程中的实验室

A planetary interior is under high-pressure and high-temperature conditions and it has a layered structure. There are two important processes that led to ...

simulation-planetary-interior-differentiation-processes

Research

JoVE Journal

Engineering

11.5K 次观看.  Carnegie Institution of Washington. 这里所描述的高压和高温实验模拟地球内部分化过程。该过程是由高分辨率三维成像和定量化学分析和可视化更好地理解。 

视频: Simulation of the Planetary Interior Differentiation Processes in the Laboratory

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted significant interests across the research fields of materials science, physics, chemistry and biology. The key enabling technology is a liquid cell. We fabricate liquid cells with thin viewing windows through a sequential microfabrication process, including silicon nitride membrane deposition, photolithographic patterning, wafer etching, cell bonding, etc. A liquid cell with the dimensions of a regular TEM grid can fit in any standard TEM sample holder. About 100 nanoliters reaction solution is loaded into the reservoirs and about 30 picoliters liquid is drawn into the viewing windows by capillary force. Subsequently, the cell is sealed and loaded into a microscope for in situ imaging. Inside the TEM, the electron beam goes through the thin liquid layer sandwiched between two silicon nitride membranes. Dynamic processes of nanoparticles in liquids, such as nucleation and growth of nanocrystals, diffusion and assembly of nanoparticles, etc., have been imaged in real time with sub-nanometer resolution. We have also applied this method to other research areas, e.g., imaging proteins in water. Liquid cell TEM is poised to play a major role in revealing dynamic processes of materials in their working environments. It may also bring high impact in the study of biological processes in their native environment.

We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.

在液体中使用液体池透射电子显微镜揭示材料的动态过程

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted ...

科研

工程学

Flame Experiments at the Advanced Light Source: New Insights into Soot Formation Processes

The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics Beamline of the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory1-4. This video demonstrates how the complex chemical structures of laboratory-based model flames are analyzed using flame-sampling mass spectrometry with tunable synchrotron-generated vacuum-ultraviolet (VUV) radiation. This experimental approach combines isomer-resolving capabilities with high sensitivity and a large dynamic range5,6. The first part of the video describes experiments involving burner-stabilized, reduced-pressure (20-80 mbar) laminar premixed flames. A small hydrocarbon fuel was used for the selected flame to demonstrate the general experimental approach. It is shown how species&#8217; profiles are acquired as a function of distance from the burner surface and how the tunability of the VUV photon energy is used advantageously to identify many combustion intermediates based on their ionization energies. For example, this technique has been used to study gas-phase aspects of the soot-formation processes, and the video shows how the resonance-stabilized radicals, such as C3H3, C3H5, and i-C4H5, are identified as important intermediates7. The work has been focused on soot formation processes, and, from the chemical point of view, this process is very intriguing because chemical structures containing millions of carbon atoms are assembled from a fuel molecule possessing only a few carbon atoms in just milliseconds. The second part of the video highlights a new experiment, in which an opposed-flow diffusion flame and synchrotron-based aerosol mass spectrometry are used to study the chemical composition of the combustion-generated soot particles4. The experimental results indicate that the widely accepted H-abstraction-C2H2-addition (HACA) mechanism is not the sole molecular growth process responsible for the formation of the observed large polycyclic aromatic hydrocarbons (PAHs).

Gas sampling from laboratory-scale flames with online analysis of all species by mass spectrometry is a powerful method to investigate the complex mixture of chemical compounds occurring during combustion processes. Coupled with tunable soft ionization via synchrotron-generated vacuum-ultraviolet radiation, this technique provides isomer-resolved information and potentially fragment-free mass spectra.

火焰在实验的先进光源：全新洞察烟灰形成过程

The following experimental protocols and the accompanying video are concerned with the flame experiments that are performed at the Chemical Dynamics ...

Laboratory Drop Towers for the Experimental Simulation of Dust-aggregate Collisions in the Early Solar System

For the purpose of investigating the evolution of dust aggregates in the early Solar System, we developed two vacuum drop towers in which fragile dust aggregates with sizes up to ~10 cm and porosities up to 70% can be collided. One of the drop towers is primarily used for very low impact speeds down to below 0.01 m/sec and makes use of a double release mechanism. Collisions are recorded in stereo-view by two high-speed cameras, which fall along the glass vacuum tube in the center-of-mass frame of the two dust aggregates. The other free-fall tower makes use of an electromagnetic accelerator that is capable of gently accelerating dust aggregates to up to 5 m/sec. In combination with the release of another dust aggregate to free fall, collision speeds up to ~10 m/sec can be achieved. Here, two fixed high-speed cameras record the collision events. In both drop towers, the dust aggregates are in free fall during the collision so that they are weightless and match the conditions in the early Solar System.

We present a technique to achieve low-velocity to intermediate-velocity collisions between fragile dust aggregates in the laboratory. For this purpose, two vacuum drop-tower setups have been developed that allow collision velocities between &#60;0.01 and ~10 m/sec. The collision events are recorded by high-speed imaging.

实验室落塔的粉尘聚集在碰撞早期太阳系的实验模拟

For the purpose of investigating the evolution of dust aggregates in the early Solar System, we developed two vacuum drop towers in which fragile dust ...

Quantification of Hydrogen Concentrations in Surface and Interface Layers and Bulk Materials through Depth Profiling with Nuclear Reaction Analysis

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and non-destructively reveals the hydrogen density distribution at surfaces, at interfaces, and in the volume of solid materials with high depth resolution. The technique applies a 15N ion beam of 6.385 MeV provided by an electrostatic accelerator and specifically detects the 1H isotope in depths up to about 2 &#956;m from the target surface. Surface H coverages are measured with a sensitivity in the order of ~1013 cm-2 (~1% of a typical atomic monolayer density) and H volume concentrations with a detection limit of ~1018 cm-3 (~100 at. ppm). The near-surface depth resolution is 2-5 nm for surface-normal 15N ion incidence onto the target and can be enhanced to values below 1 nm for very flat targets by adopting a surface-grazing incidence geometry. The method is versatile and readily applied to any high vacuum compatible homogeneous material with a smooth surface (no pores). Electrically conductive targets usually tolerate the ion beam irradiation with negligible degradation. Hydrogen quantitation and correct depth analysis require knowledge of the elementary composition (besides hydrogen) and mass density of the target material. Especially in combination with ultra-high vacuum methods for in-situ target preparation and characterization, 1H(15N,&#945;&#947;)12C NRA is ideally suited for hydrogen analysis at atomically controlled surfaces and nanostructured interfaces. We exemplarily demonstrate here the application of 15N NRA at the MALT Tandem accelerator facility of the University of Tokyo to (1) quantitatively measure the surface coverage and the bulk concentration of hydrogen in the near-surface region of a H2 exposed Pd(110) single crystal, and (2) to determine the depth location and layer density of hydrogen near the interfaces of thin SiO2 films on Si(100).

We illustrate the application of 1H(15N,&#945;&#947;)12C resonant nuclear reaction analysis (NRA) to quantitatively evaluate the density of hydrogen atoms on the surface, in the volume, and at an interfacial layer of solid materials. The near-surface hydrogen depth profiling of a Pd(110) single crystal and of SiO2/Si(100) stacks is described.

通过与核反应分析深度剖面的表面和界面层和颗粒材料氢含量的定量

Nuclear reaction analysis (NRA) via the resonant 1H(15N,&#945;&#947;)12C reaction is a highly effective method of depth profiling that quantitatively and ...

Simulation of Human-induced Vibrations Based on the Characterized In-field Pedestrian Behavior

For slender and lightweight structures, vibration serviceability is a matter of growing concern, often constituting the critical design requirement. With designs governed by the dynamic performance under human-induced loads, a strong demand exists for the verification and refinement of currently available load models. The present contribution uses a 3D inertial motion tracking technique for the characterization of the in-field pedestrian behavior. The technique is first tested in laboratory experiments with simultaneous registration of the corresponding ground reaction forces. The experiments include walking persons as well as rhythmical human activities such as jumping and bobbing. It is shown that the registered motion allows for the identification of the time variant pacing rate of the activity. Together with the weight of the person and the application of generalized force models available in literature, the identified time-variant pacing rate allows to characterize the human-induced loads. In addition, time synchronization among the wireless motion trackers allows identifying the synchronization rate among the participants. Subsequently, the technique is used on a real footbridge where both the motion of the persons and the induced structural vibrations are registered. It is shown how the characterized in-field pedestrian behavior can be applied to simulate the induced structural response. It is demonstrated that the in situ identified pacing rate and synchronization rate constitute an essential input for the simulation and verification of the human-induced loads. The main potential applications of the proposed methodology are the estimation of human-structure interaction phenomena and the development of suitable models for the correlation among pedestrians in real traffic conditions.

A protocol is presented for the characterization of the in-field pedestrian behavior and the simulation of the resulting structural response. Field-tests demonstrate that the in situ identified pacing rate and synchronization rate among the participants constitute an essential input for the simulation and verification of the human-induced loads.

基于该特征场行人行为人类引起的振动模拟

For slender and lightweight structures, vibration serviceability is a matter of growing concern, often constituting the critical design requirement. With ...

Knowledge Based Cloud FE Simulation of Sheet Metal Forming Processes

The use of Finite Element (FE) simulation software to adequately predict the outcome of sheet metal forming processes is crucial to enhancing the efficiency and lowering the development time of such processes, whilst reducing costs involved in trial-and-error prototyping. Recent focus on the substitution of steel components with aluminum alloy alternatives in the automotive and aerospace sectors has increased the need to simulate the forming behavior of such alloys for ever more complex component geometries. However these alloys, and in particular their high strength variants, exhibit limited formability at room temperature, and high temperature manufacturing technologies have been developed to form them. Consequently, advanced constitutive models are required to reflect the associated temperature and strain rate effects. Simulating such behavior is computationally very expensive using conventional FE simulation techniques.
This paper presents a novel Knowledge Based Cloud FE (KBC-FE) simulation technique that combines advanced material and friction models with conventional FE simulations in an efficient manner thus enhancing the capability of commercial simulation software packages. The application of these methods is demonstrated through two example case studies, namely: the prediction of a material's forming limit under hot stamping conditions, and the tool life prediction under multi-cycle loading conditions.

The following paper presents a novel FE simulation technique (KBC-FE), which reduces computational cost by performing simulations on a cloud computing environment, through the application of individual modules. Moreover, it establishes a seamless collaborative network between world leading scientists, enabling the integration of cutting edge knowledge modules into FE simulations.

板料成形过程的知识基于云的有限元模拟

The use of Finite Element (FE) simulation software to adequately predict the outcome of sheet metal forming processes is crucial to enhancing the ...

Wicking Tests for Unidirectional Fabrics: Measurements of Capillary Parameters to Evaluate Capillary Pressure in Liquid Composite Molding Processes

During impregnation of a fibrous reinforcement in liquid composite molding (LCM) processes, capillary effects have to be understood in order to identify their influence on void formation in composite parts. Wicking in a fibrous medium described by the Washburn equation was considered equivalent to a flow under the effect of capillary pressure according to the Darcy law. Experimental tests for the characterization of wicking were conducted with both carbon and flax fiber reinforcement. Quasi-unidirectional fabrics were then tested by means of a tensiometer to determine the morphological and wetting parameters along the fiber direction. The procedure was shown to be promising when the morphology of the fabric is unchanged during capillary wicking. In the case of carbon fabrics, the capillary pressure can be calculated. Flax fibers are sensitive to moisture sorption and swell in water. This phenomenon has to be taken into account to assess the wetting parameters. In order to make fibers less sensitive to water sorption, a thermal treatment was carried out on flax reinforcements. This treatment enhances fiber morphological stability and prevents swelling in water. It was shown that treated fabrics have a linear wicking trend similar to those found in carbon fabrics, allowing for the determination of capillary pressure.

An experimental method to measure geometrical parameters and the apparent advancing contact angles describing capillary wicking in unidirectional synthetic and natural fabrics is proposed. These parameters are mandatory for the determination of the capillary pressures that must be taken into account for liquid composite molding (LCM) applications.

吸湿排汗试验单向织物：毛细管参数的标准评价在液体复合成型工艺毛细管压力

During impregnation of a fibrous reinforcement in liquid composite molding (LCM) processes, capillary effects have to be understood in order to identify ...

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and nanocrystalline materials. The traditional techniques associated with scanning electron microscopy (SEM), such as electron backscatter diffraction (EBSD), do not possess the required spatial resolution due to the large interaction volume between the electrons from the beam and the atoms of the material. Transmission electron microscopy (TEM) has the required spatial resolution. However, due to a lack of automation in the analysis system, the rate of data acquisition is slow which limits the area of the specimen that can be characterized. This paper presents a new characterization technique, Transmission Kikuchi Diffraction (TKD), which enables the analysis of the microstructure of UFG and nanocrystalline materials using an SEM equipped with a standard EBSD system. The spatial resolution of this technique can reach 2 nm. This technique can be applied to a large range of materials that would be difficult to analyze using traditional EBSD. After presenting the experimental set up and describing the different steps necessary to realize a TKD analysis, examples of its use on metal alloys and minerals are shown to illustrate the resolution of the technique and its flexibility in term of material to be characterized.

This paper provides a detailed method to characterize the microstructure of ultra-fine grained and nanocrystalline materials using a scanning electron microscope equipped with a standard electron backscatter diffraction system. Metal alloys and minerals presenting refined microstructures are analyzed using this technique, showing the diversity of its possible applications.

超细晶和纳米晶材料的表征采用透射菊池衍射

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and ...

Processing of Bulk Nanocrystalline Metals at the US Army Research Laboratory

Given their potential for significant property improvements relative to their large grained counterparts, much work has been devoted to the continued development of nanocrystalline metals. Despite these efforts, the transition of these materials from the lab bench to actual applications has been blocked by the inability to produce large scale parts that retain the desired nanocrystalline microstructures. Following the development of a method proven to stabilize the nanosized grain structure to temperatures approaching that of the melting point for the given metal, the US Army Research Laboratory (ARL) has progressed to the next stage in the development of these materials - namely the production of large scale parts suitable for testing and evaluation in a range of relevant test environments. This report provides a broad overview of the ongoing efforts in the processing, characterization, and consolidation of these materials at ARL. In particular, focus is placed on the methodology used for producing the nanocrystalline metal powders, in both small and large-scale amounts, that are at the center of ongoing research efforts.

This paper provides a brief overview of the ongoing efforts at the Army Research Laboratory on the processing of bulk nanocrystalline metals with an emphasis on the methodologies used for the production of the novel metal powders.

美国陆军研究实验室散装纳米晶金属的加工

Given their potential for significant property improvements relative to their large grained counterparts, much work has been devoted to the continued ...

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57Fe isotope, namely M&#246;ssbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. M&#246;ssbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of M&#246;ssbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.

结构转换的原位和原位研究方法: 金属玻璃结晶的实例

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic ...