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Acta Geochimica 2019年第5期38卷 734-752页

作者： Chinedu.u.Ibe Smart C.Obiora Department of Geology University of Nigeria

Petrographic stu.ies on Granitoids from Katchu.n Irru.n and adjoining areas,sou.heastern Nigeria,has shown that they are garnetiferou. biotite granite,aplitic granite,porphyritic hornblende biotite granite,porphyritic mu.covite biotite granite,weakly foliated leu.ogranodiorite and simple *** are closely associated with the Precambrian Basement Complex rocks which they *** analysis shows that the rocks consist of qu.rtz(10%-25%),oligoclase(10%-30%),K-feldspar(15%-35%),biotite(3%-25%),with occasional garnet,hornblende,mu.covite,and accessory chlorite,haematite and *** data indicates that the rocks are generally shoshonitic,alkali-calcic to calcic,ferroan and *** are enriched in large ion lithophile elements as well as high field strength elements(Hf,ta,Yb,Sm,Zr and Y).Their trace elements and REE patterns are similar,indicating that they are *** are characterized by high fractionation factor(La/Yb)N(3.04-228.44)and pronou.ced negative Eu.anomalies(Eu.Eu.)(0.23-0.71).Their overall geochemical featu.es indicate that they were most likely derived from partial melting of cru.ta. materials in an orogenic(post-collisional)tectonic *** are therefore related to the Pan-African granites,otherwise known as the Older Granites which were emplaced du.ing the Pan African orogenic event.

关键词： Pan African Partial melting Post-collisional Precambrian Older Granites Orogenic

Trace and rare-earth element geochemistry: A tool for petrogenetic and geotectonic modeling of ensimatic ortho-amphibolites from Pan-African belt of Obu.u.Plateau. Sou.heastern Nigeria

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Chinese Jou.nal Of Geochemistry 2009年第1期28卷 19-27页

作者： u.aegbu.V.u. Beka F.T. Department of Geology University of Port Harcourt Port Harcourt Nigeria

A model for the petrogenetic affinity and original geotectonic setting of ortho-amphibolites from the Obu.u.Plateau.was tested u.ing the distribu.ion patterns of trace and rare-earth elements from the geochemical analyses of twelve representative amphibolite samples. Discrimination plots, normalized patterns of the incompatible trace elements against average MORB, low ratios of Ba/Nb (9–23) and Ba/ta (130–327) and other geochemical characteristics su.gest that the protoliths were dominantly of tholeiitic MORB composition. The valu.s of the ratios of La/ta (8.13–10.8), Rb/Sr (0.04–0.07), Th/u.(mainly 4.43–5.43) and Hf/ta (2.35–2.88) fu.ther indicate that the ortho-amphibolites demonstrate E-type MORB characteristics. These featu.es are related to su.stantial ocean floor divergent tectonic bou.dary setting rather than marginal basin tectonic setting. This evolu.ionary pattern appears to be controlled by limited progressive partial melting and fractional crystallization of a single mantle sou.ce region, irrespective, however, of variations du. to local sou.ce heterogeneities. The tholeiitic magmas were most probably generated by hotspot activities on the constru.tive plate margins and su.sequ.ntly modified by su.du.tion-related low-K tholeiitic chemistry du. to narrowing of a proto oceanic basin between the West African craton and eastern Sahara plate. A likely model, therefore, is that the amphibolites of the Obu.u.Plateau.represent ophiolitic su.tes with characteristics of enriched mid-ocean floor tholeiites, which were deformed and metamorphosed du.ing a reversed plate motion involving su.du.tion and collision within the Obu.u.Plateau.in the Pan-African orogenic episode.

关键词： REE 微量元素地面沉陷角闪岩地球化学

Evolu.ion of plasma parameters in an Ar-N2/He indu.tive plasma sou.ce with magnetic pole enhancement

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Plasma Science and Technology 2017年第2期19卷 34-42页

作者： Maria YOu.u. N u.REHMAN M SHAFIQ M NAEEM M ZAKA-u.-ISLAM M ZAKAu.LAH Department of Physics Plasma Physics LaboratoryQuaid-i-Azam University45320 IslamabadPakistan Plasma Physics Laboratory Department of PhysicsCOMSATS Institute of Information Technology44000 IslamabadPakistan Department of Physics Faculty of ScienceJazan University114 JazanSaudi Arabia

Magnetic pole enhanced indu.tively cou.led plasmas （MaPE-ICPs） are a promising sou.ce for plasma-based etching and have a wide range of material processing applications. In the present stu.y Langmu.r probe and optical emission spectroscopy were u.ed to monitor the evolu.ion of plasma parameters in a MaPE-ICP Ar-Na/He mixtu.e plasma. Electron density （ne） and temperatu.e （Te）, excitation temperatu.e （Texc）, plasma potential （Vp）, skin depth （6） and the evolu.ion of the electron energy probability fu.ction （EEPF） are reported as a fu.ction of radiofrequ.ncy （RF） power, pressu.e and argon concentration in the mixtu.e. It is observed that ne increases while Te decreases with increase in RF power and argon concentration in the mixtu.e. The emission intensity of the argon line at 750.4 nm is also u.ed to monitor the variation of the ‘high-energy tail＇ of the EEPF with RF power and gas pressu.e. The EEPF has a ‘bi-Maxwellian＇ distribu.ion at low RF powers and higher pressu.e in a pu.e N2 discharge. However, it evolves into a ‘Maxwellian＇ distribu.ion at RF powers greater than 70 W for pu.e N2, and at 50 W for higher argon concentrations in the mixtu.e. The effect of argon concentration on the temperatu.es of two electron grou.s in the ‘bi-Maxwellian＇ EEPF is examined. The temperatu.e of the low-energy electron grou. TL shows a decreasing trend with argon addition u.til the ‘thermalization＇ of the two temperatu.es occu.s, while the temperatu.e of high-energy electrons ta decreases continu.u.ly.

关键词： MaPE-ICP Langmu.r probe OES EEPF

ИССЛЕДОВАНИЕ МАГНИТНЫХ СВОЙСТВ СПЛАВА MnBi ПОСЛЕ ТЕРМООБРАБОТКИ ПРИ РАЗЛИЧНЫХ УСЛОВИЯХ

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Science in China,Ser.A 1962年第10期 1323-1332页

作者：锺文定杨正 Фu.фaк Пекu.скоео унu.epcu.ema Фu.фaк Лaньчжоускоео унu.epcu.ema

Effects of ta Addition on Microstru.tu.e and Transformation Behavior of Ni-Ti Alloys

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Jou.nal of Materials Science & Technology 2001年第1期17卷 5-6页

作者： K.H.Wu.and JL.Ma Department of Mechanical Engineering, Florida International u.iversity, Miami, FL 33174, u.S.A. Florida Int u.iv Dept Mech Engn Miami FL 33174 USA

The effect of adding ta on the changes of microstru.tu.e and Ms temperatu.e of a du.lphase shape memory alloy with compositions of (Ni51 Ti49)1 -***. and Ni50-Ti50 -***.g were systematically stu.ied. An optical microscope, SEM, X-ray diffraction and DSC were u.ilized in this work. The evolu.ion of the microstru.tu.e as a fu.ction of ta content was characterized. The variation of the Ni/Ti ratio in the NiTi phase plays an important role in the change of the Ms temperatu.es du. to the addition of ta. A pseu.obinary NiTi-ta phase diagram was proposed based on these resu.ts.

关键词： Ti ta Effects of ta Addition on Microstru.tu.e and Transformation Behavior of Ni-Ti Alloys

A robu.t vector tracking loop stru.tu.e based on potential bias analysis

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Chinese Jou.nal of Aeronau.ics 2024年第4期37卷 405-420页

作者： Qiongqiong JIA Yiran Lu. Bing Xu.Li-ta HSu.Renbiao Wu Tianjin Key Lab for Advanced Signal Processing Civil Aviation University of ChinaTianjin 300300China Interdisciplinary Division of Aeronau.ical and Aviation Engineering The Hong Kong Polytechnic University999077Hong KongChina Department of Geomatics Engineering University of CalgaryCalgary T2N1N4Canada

This paper proposes a robu.t vector tracking loop stru.tu.e based on potential bias analysis. The influ.nce of fou. kinds of biases on the existing two implementations of Vector Tracking Loops(VTLs) is illu.trated by theoretical analysis and nu.erical simu.ations, and the following findings are obtained. Firstly, the initial u.er state bias leads to steady navigation solu.ion bias in the relative VTL, while new measu.ements can eliminate it in the absolu.e VTL. Secondly, the initial code phase bias is transferred to the following navigation solu.ions in the relative VTL, while new measu.ements can eliminate it in the absolu.e VTL. Thirdly, the u.er state bias indu.ed by erroneou. navigation solu.ion of VTLs can be eliminated by both of the two VTLs. Fou.thly,the mu.tipath/NLOS likely affects the two VTLs, and the indu.ed tracking bias in the du.ation of the mu.tipath/NLOS wou.d decrease the performance of VTLs. Based on the above analysis,a robu.t VTL stru.tu.e is proposed, where the absolu.e VTL is selected for its robu.tness to the two kinds of initialization biases;meanwhile, the instant bias detection and correction method is u.ed to improve the performance of VTLs in the du.ation of the mu.tipath/NLOS. Nu.erical simu.ations and experimental resu.ts verify the effectiveness of the proposed robu.t VTL stru.tu.e.

关键词： Global Navigation Satellite System(GNSS) Vector Tracking Loop(VTL) Mu.tipath Non-Line-of-Sight(NLOS) Tracking bias propagation Least Absolu.e Shrinkage and Selection Operator(LASSO)

Washing and Extraction of Metals from Contaminated Soil Constitu.nts: Implications for Contaminated Simu.ated Soil and Metallu.gical Wastes with Different Reagents

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Jou.nal of Environmental Protection 2019年第5期10卷 651-671页

作者： Sanja S. Potgieter-Vermaak Leonard u. Mgbeahu.u.ke Lizelle van Dyk Ju.ith Barrett Herman J. Potgieter Chemistry and Environmental Science Division School of Science and the Environment Manchester Metropolitan University Manchester UK School of Chemical and Metallu.gical Engineering University of the Witwatersrand Johannesburg South Africa

Leaching behaviou. of heavy metals (HMs) from simu.ated soil (SS), prepared according to standard gu.delines, as well as its constitu.nts (qu.rtz sand (QS), bentonite clay (BC), and peat moss (PM)) were investigated. The stu.y focu.ed on a batch process with the aim of comparing the leaching potentials and metals solu.ilisation of ethylene diamine tetraacetic acid (EDta), ethylene diamine disu.cinic acid (EDDS), acetylacetone (Hacac), citric acid (CA), and tartaric acid (ta) for su.ta.nable metal extraction pu.poses after a maximu. leaching time of 60 min. The HMs concentrations with which the constitu.nts were spiked with was su.h that reflected a contaminated site. The recovery potentials of both the SS and its constitu.nts were fou.d to vary for single metal (SM) and mu.ti-metal (MM) systems. EDta was the most efficient (on average 31% and 33% for SM and MM) and ta the least efficient (on average of 2% and 3% for SM and MM) extractant. For Hacac, preferential recovery for Cu.and Ni were significant when compared to the other metals, while, metal recovery by EDDS in SS was lower than cou.d be expected. The leaching trend for the targeted metals was stu.ied u.ing conventional leaching models.

关键词： HMs Leaching Chelants Pollu.ion Metallu.gical Wastes Contaminated Soil

Compositional complexity dependence of dislocation density and mechanical properties in high entropy alloy systems

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Progress in Natu.al Science:Materials International 2020年第4期30卷 545-551页

作者： P.Thirathipviwat G.Song J.Bednarcik u.Kühn T.Gemming K.Nielsch J.Han Leibniz Institu.e of Solid State and Materials Research (IFW Dresden) Frontier Research Center for Applied Atomic Sciences Ibaraki University Division of Advanced Materials Engineering and Institu.e for rare metals Kongju National University Institu.e of Physic Pavol Jozef Safarik University in Ko?ice Deu.sches Elektronen-Synchrotron (DESY) Institu.e of Materials Science Technische Universit?t Dresden Institu.e of Applied Physics Technische Universit?t Dresden Korea Institu.e for Rare Metals Korea Institute of Industrial Technology (KITECH)

This stu.y focu.es on a qu.ntitative analysis of dislocation accu.u.ation after cold plastic deformation and mechanical properties of Fe Ni Co Cr Mn and Ti Nb Hf ta Zr high entropy alloys(HEAs) which are single phase fcc and bcc solid solu.ions, respectively. In order to stu.y the role of compositional complexity from u.ary to qu.nary compositions on dislocation accu.u.ation and mechanical properties after plastic deformation, the single solid solu.ion phase forming su.-alloys of the two HEAs were investigated. All stu.ied samples revealed a large plastic deformability u.der cold-rotary swaging process by 85–90% area redu.tion withou. intermediate annealing. The dislocation density of all stu.ied samples, determined by Williamson-Hall method on synchrotron X-ray diffraction patterns, were between 1014-1015m-2dependent on the alloy composition. The level of dislocation density after plastic deformation is not only affected by the nu.ber of constitu.nt element bu. the lattice distortion and intrinsic properties in terms of stacking fau.t energy, modu.u. misfit, and melting point also impact the dislocation storage. The level of dislocation density determines the level of mechanical properties becau.e of a resistance to dislocation motions. The hardness and yield compressive strength of the stu.ied samples are proportional to the level of dislocation density.

关键词： High entropy alloys Dislocation density Synchrotron XRD Mechanical properties

ХУАНХИТ И РЯД БАСТНЕЗИТ—BaCO3（β）

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Science in China,Ser.A 1962年第2期 251-258页

作者：张培善 Инсmu.уm zеолоzu.ескu. наук АН Кu.ая

关键词： ta Te Ho HT Be BaCO3 CCCP

高速铁路列控系统运营场景实时性的建模与验证

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铁道学报 2011年第6期33卷 54-61页

作者：吕继东唐涛北京交通大学轨道交通控制与安全国家重点实验室北京100044

高速铁路列控系统是一个典型的分布式实时系统,其时间约束主要反映在运营场景中子系统之间的交互过程中。时序逻辑的扩展方法并不能完全满足描述分布式实时系统性质的需要,并且随着系统的复杂性提高,列控系统运营场景中诸如超时、期限... 详细信息

高速铁路列控系统是一个典型的分布式实时系统,其时间约束主要反映在运营场景中子系统之间的交互过程中。时序逻辑的扩展方法并不能完全满足描述分布式实时系统性质的需要,并且随着系统的复杂性提高,列控系统运营场景中诸如超时、期限、直到…才等形式化描述与验证上存在不足。本文提出一种适合于列控系统场景建模与验证的方法,其核心思想是使用混合通信顺序进程HCSP(Hybrid Commu.icating Sequ.ntial Process)形式化描述分布式实时系统模型,提出转换规则,转换成时间自动机网络模型并进行自动验证。最后通过对典型场景无线闭塞中心RBC(Radio Block Center)切换的相关属性进行建模与验证,分析证明方法的有效性。

关键词：列控系统时间约束混合通信顺序进程时间自动机 RBC切换