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Partitioning behavior between amphibole and silicate glass of thirty-three minor and trace elements(Sc,Ti, V, Cr, Co, Rb, Sr, P, Y, Zr, Nb, Cs, Ba, K, La, Ce, Pr,Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, Pb,Th, and U) have been determined experimentally. Products of crystallization of hydrous basalt melts from 0.6 GPa/860 °C up to 2.6 GPa/970 °C were obtained in a multianvil apparatus. Major and trace element compositions of amphibole and glass were determined with a combination of electron microprobe and laser ablation inductively coupled plasma mass spectrometry. The main mineral phase is calcic amphibole, and the coexisting glass compositions are tonalite, granodiorite, and granite. The compatibility of rare earth elements increase at 915 °C and then decrease at 970 °C, but the compatibility of most of these elements shows a continued, significant increase with increasing pressure. For high-field strength elements, large ion lithophile elements, actinide compatibility decrease with increasing temperature or pressure, but transition metals show a continued increase in compatibility within the temperature–pressure conditions. From mathematical and graphical fitting, we determined best-fit values for the ideal ionic radius(r_0, 1.01–1.04 ?), the strain-free partitioncoefficient(D_0, 1.18–1.58), and apparent Young's modulus(E, 142–370 GPa) for the M4 site in amphibole according to the lattice strain model. The D_0M4 for rare earth elements rises at 915 °C and then drops at 970 °C at 0.6 GPa.However, the D_0M4 values are positively proportional to the pressure for rare earth elements in the amphibole-glass pairs at 0.6–2.6 GPa and 970 °C. Furthermore, the derived best-fit values for r_0M4 and EM4 are almost constant and trend to increase with rising temperature and pressure,respectively. The partition coefficient is distinctly different for different melt compositions. The rare earth elements become more enriched in amphibole if the quenched glass is granodiorite or granite compared to the tonalitic glasses. 相似文献
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刘后旺,字雁宾、号了然堂主、半无散人。1960年出生于浙江温州雁荡山,现居杭州。国家一级美术师,中国黄宾虹学术研究会会员、中国美院张伟平（仁量）教授工作室助教,其山水画作品多次参加全国美展并获奖。书画,人之意念融于造化之物,使之外化形式,内聚神韵。若以三品论之,则下品虚笔飘忽,实笔呆滞,笔连而韵断,画形而神散;中品虚笔不飘,实笔不呆,笔断而韵连,画白而神现;上品者,虚笔云中隐山,实笔山中飘雪,笔散而神聚,画聚而意散。是故,下品如草木,生于春死于秋,三季之作;中品如树木,百载春秋,一世之作也;上品如山水,度千秋历万代,永世之作也。 相似文献
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氮及氮磷比对附着藻类及浮游藻类的影响 总被引：5，自引：0，他引：5
2005年5月至11月,在河北省YH水库选取5个具有代表性的样点,进行了微囊藻毒素-LR的调查,同时,测定了相应各样点的TN,TP,NH4-N,NO3-N和PO4-P.结果显示,水库中微囊藻毒素-LR(MC-LR)随季节发生变化,其中,7-10月期间相对较高,且大部分超过了生活饮用水地表水标准限值(1 μg/L);MC-LR与水体中的N、P之间的相互关系表明,5-7月期间,水库MC-LR与TP呈正相关,与NH4-N和TN/TP呈负相关;8-9月期间,水库中TP逐渐降低,但其它降低速率低于TN,造成TN/TP明显降低,MC-LR与TP和TN/TP呈正相关,与NH4-N呈负相关;10-11月期间,大量藻细胞死亡,释放到水体中MC-LR也逐渐下降,这时,大量外源营养盐也进入水库,造成微囊藻毒素-LR的变化与TN、NH4-N、NO3-N呈显著或极显著负相关.这说明在不同季节下,微囊藻毒素-LR与营养盐的关系不同,必须视实际情况而定. 相似文献
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Weijie SUN Ryan MDEWEY Sae AIZAWA Jia HUANG James A.SLAVIN Suiyan FU Yong WEI Charles F.BOWERS 《中国科学:地球科学(英文版)》2022,65(1):25-74
This review paper summarizes the research of Mercury’s magnetosphere in the Post-MESSENGER era and compares its dynamics to those in other planetary magnetospheres,especially to those in Earth’s magnetosphere.This review starts by introducing the planet Mercury,including its interplanetary environment,magnetosphere,exosphere,and conducting core.The frequent and intense magnetic reconnection on the dayside magnetopause,which is represented by the flux transfer event"shower",is reviewed on how they depend on magnetosheath plasma β and magnetic shear angle across the magnetopause,followed by how it contributes to the flux circulation and magnetosphere-surface-exosphere coupling.In the next,Mercury’s magnetosphere under extreme solar events,including the core induction and the reconnection erosion on the dayside magnetosphere,as well as the responses of the nightside magnetosphere,are reviewed.Then,the dawn-dusk properties of the plasma sheet,including the features of the ions,the structure of the current sheet,and the dynamics of magnetic reconnection,are summarized.The last topic is devoted to the particle energization in Mercury’s magnetosphere,which includes the energization of the Kelvin-Helmholtz waves on the magnetopause boundaries,reconnection-generated magnetic structures,and the cross-tail electric field.In each chapter,the last section discusses the open questions related to each topic,which can be considered by the simulations and the future spacecraft mission.We end this paper by summarizing the future Bepi Colombo opportunities,which is a joint mission of ESA and JAXA and is en route to Mercury. 相似文献
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To display the distribution characteristics of turbulence eddy under condition of complex terrain in Loess Plateau,and to enhance the precision of turbulence measurements,the research of turbulence ergodicity is considered to be the prior section of the experiment.With the statistics of single-site turbulence measurements obtained in Baimiao Tableland,Ping Liang,Gan Su,analysis result shows that not only the turbulence with scale less than 10 min,which can easily satisfy the ergodicity,the tableland terrain can also be a major cause of the coherent structure of periodic,large-scale turbulence;compared to which for the turbulence above the flat underlying surface,the distribution of 10–40 min,large-scale turbulence in the tableland region tends to be more steady and,thus,can also satisfy the ergodicity easily.Under the condition of extremely unstable stratification,the wind is comparatively low in speed and features distinctly large-scale,periodical fluctuation,and with the trend of smooth increase in temperature,large-scale wind turbulence and temperature turbulence both tend to satisfy ergodicity.In comparison,under the condition of extremely stable stratification,the aperiodicity of large-scale wind turbulence and temperature turbulence caused by intermittency is comparatively strong,and the turbulence cannot satisfy ergodicity easily. 相似文献
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Fu Huishan Grigorenko Elena E. Gabrielse Christine Liu Chengming Lu San Hwang K. J. Zhou Xuzhi Wang Zhe Chen Fang 《中国科学:地球科学(英文版)》2020,63(2):235-256
In this paper, the particle acceleration processes around magnetotail dipolarization fronts(DFs) were reviewed. We summarize the spacecraft observations(including Cluster, THEMIS, MMS) and numerical simulations(including MHD, testparticle, hybrid, LSK, PIC) of these processes. Specifically, we(1) introduce the properties of DFs at MHD scale, ion scale, and electron scale,(2) review the properties of suprathermal electrons with particular focus on the pitch-angle distributions,(3)define the particle-acceleration process and distinguish it from the particle-heating process,(4) identify the particle-acceleration process from spacecraft measurements of energy fluxes, and(5) quantify the acceleration efficiency and compare it with other processes in the magnetosphere(e.g., magnetic reconnection and radiation-belt acceleration processes). We focus on both the acceleration of electrons and ions(including light ions and heavy ions). Regarding electron acceleration, we introduce Fermi,betatron, and non-adiabatic acceleration mechanisms;regarding ion acceleration, we present Fermi, betatron, reflection, resonance, and non-adiabatic acceleration mechanisms. We also discuss the unsolved problems and open questions relevant to this topic, and suggest directions for future studies. 相似文献
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The Bayan Obo deposit in northern China is an ultra-large Fe–REE–Nb deposit.The occurrences,and geochemical characteristics of thorium in iron ores from the Bayan Obo Main Ore Body were examined using chemical analysis,field emission scanning electron microscopy,energy dispersive spectrometer,and automatic mineral analysis software.Results identified that 91.69%of ThO2 in the combined samples was mainly distributed in rare earth minerals(bastnaesite,huanghoite,monazite;56.43%abundance in the samples),iron minerals(magnetite,hematite,pyrite;20.97%),niobium minerals(aeschynite;14.29%),and gangue minerals(aegirine,riebeckite,mica,dolomite,apatite,fluorite;4.22%).An unidentified portion(4.09%)of ThO2 may occur in other niobium minerals(niobite,ilmenorutile,pyrochlore).Only a few independent minerals of thorium occur in the iron ore samples.Thorium mainly occurs in rare earth minerals in the form of isomorphic substitution.Analyses of the geochemical characteristics of the major elements indicate that thorium mineralization in the Main Ore Body was related to alkali metasomatism,which provided source material and favorable porosity for hydrothermal mineralization.Trace elements such as Sc,Nb,Zr,and Ta have higher correlation coefficients with thorium,which resulted from being related to the relevant minerals formed during thorium mineralization.In addition,correlation analysis of ThO2 and TFe,and REO and TFe in the six types of iron ore samples showed that ThO2 did not always account for the highest distribution rate in rare earth minerals,and the main occurrence minerals of ThO2 were closely related to iron ore types. 相似文献
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在5.12汶川8级特大地震灾区的抗震救灾队伍中,有13万解放军,武警,消防将士,有十余万各行各业的抢修,抢险,救护,防疫等专业救援队伍,还有众多自发的志愿者,如,成都市的老兵志愿者队,唐山市志愿者队,大中专院校学生志愿者…… 相似文献
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吴子书,笔名"子书",字"虞心",号"双辑堂主人",别称"清心夫子"。吴子书自幼善书好写,研习书帖、碑刻、篆印。十七岁时正式学习书法,凭其天资聪慧,博众家之长,耕耘于执白守黑之间,挥洒于真草隶篆之中。吴子书的书法,绝名超美,灵姿秀俊。章法有制,狂中不燥。其超然之气度,天地合一之魂韵,令众人瞠目。欧阳先生说:大开大合者有,而当 相似文献
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一年一度的奥斯卡颁奖典礼虽然落下了帷幕,但美妆华服的余温却未散去。每一次,盛典都是那么激动人心;每一次,盛典都是那么星光闪耀。当然,每一次,和明星们一样闪耀的还有那些创意独特、精致奢华的珠宝首饰。这些灵动的精灵们,随着光艳照人的明星一起亮相奥斯卡的红地毯,搭配着光鲜亮丽的锦衣罗缎,让明星们瞬间变得尊贵耀眼。可以说,每一次的奥斯卡红地毯,就是一次永恒瞬 相似文献
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正北京时间2013年4月20日8时02分,在四川,在雅安,在芦山,本来应该是一个有美好开始的早晨,也应该是一个安静的早晨,然而不应该动的却动了,天降灾难地动山摇,不应该毁的也毁了。一场灾难突然袭击,来不及逃脱,老天爷又跟四川开了个玩笑。雅安,不久的将来,你的世界,仍会春暖花开。8时02分四川省雅安市芦山县发生7.0级地震。震源深度13公里。截至4月27日8时,地震遇难人数升至 相似文献
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“自古黄山天下奇”,“黄山之奇,信在诸峰;诸蜂之奇,信在松石;松石之奇,信在拙古;云雾之奇,信在铺海。”横空峰峦,浩淼云烟,奔泄飞瀑,嶙峋巧石,奇特青松,无不展现着黄山的壮美风姿。去年初冬,是我拍摄中国20家世界地质公园的最后一站,我独自一人来到了黄山。黄山位于中国东部安徽省南部,其中精华部分154平方公里。黄山以其壮丽的景色,特别是生长在花岗岩石上的奇松和浮现在云海中的怪石,彰显永恒的魅力,享有“五岳归来不看山,黄山归来不看岳”的美誉。 相似文献