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西太平洋麦哲伦海山群Hemler、Vlinder和Il’ichev海山熔岩的成因及其形成的深部动力学机制

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中国科学：地球科学 2024年第6期54卷 1883-1900页

作者：位荀张艳石学法张辉自然资源部第一海洋研究所海洋地质与成矿作用重点实验室青岛266061 青岛海洋科技中心海洋地质过程与环境功能实验室青岛266237 山东省深海矿产资源开发重点实验室(筹) 青岛266061

经典的“地幔柱假说”能够很好解释年龄随空间位置线性变化的大洋板内火山链的成因.而位于西太平洋的众多海山群,空间分布广、年龄-位置关系杂乱,很难用经典的“地幔柱假说”来解释,其成因存在争议.本研究选择西太平洋麦哲伦海山群Hemle... 详细信息

经典的“地幔柱假说”能够很好解释年龄随空间位置线性变化的大洋板内火山链的成因.而位于西太平洋的众多海山群,空间分布广、年龄-位置关系杂乱,很难用经典的“地幔柱假说”来解释,其成因存在争议.本研究选择西太平洋麦哲伦海山群Hemler、Vlinder和Il’ichev海山熔岩,对其进行40Ar-39Ar年代学、主量和微量元素以及Sr-Nd-Pb-Hf同位素分析,来揭示其岩石成因和形成的深部动力学机制. Hemler、Vlinder和Il’ichev海山熔岩属于碱性玄武岩、碧玄岩/霞石岩和粗面岩, MgO>8wt.%的熔岩具有较高的CaO、FeOT和TiO2含量,是碳酸盐化榴辉岩熔融的熔体与橄榄岩反应的产物.这些熔岩具有较高的Zr/Hf比值(40.6~45.2)和Zr-Hf负异常,指示它们的地幔源区存在碳酸盐组分. Hemler、Vlinder和Il’ichev海山熔岩富集不相容元素,其Sr-Nd-Pb-Hf同位素显示EM1(1型富集地幔)特征,与Rarotonga和Samoa热点相似.虽然产出于同一个海山, Il’ichev碱性玄武岩与Il’ichev碧玄岩的同位素组成明显不同:前者具有更为亏损的Sr-Nd-Hf同位素特征.结合板块构造恢复结果, Hemler(100.1Ma)、Vlinder造盾前(100.2Ma)和造盾期后((87.5±0.4)Ma)以及Il’ichev((56.4±1.2)Ma)海山熔岩的形成时间明显偏离了南太平洋Macdonald、Arago、Rarotonga和Samoa热点的运移轨迹,因此它们并非来源于深部地幔柱的直接熔融,更可能是浅部过程的产物.麦哲伦海山群所在的大洋板块的一个典型特征是:岩石圈断裂带在该区域广泛分布.我们提出,在中白垩世当麦哲伦海山群所在的太平洋板块经过Rarotonga地幔柱上方时, Rarotonga地幔柱直接熔融形成Vlinder(造盾期)、Pako和Ioah海山.随着地幔对流分散在周围软流圈中的Rarotonga和Samoa地幔柱物质,在岩石圈裂隙处发生减压熔融,形成Hemler和Vlinder造盾前和造盾期后熔岩;Il’ichev海山碱性玄武岩和碧玄岩是岩石圈裂隙诱发的软流圈中不均一富集组分熔融的产物.这种不均一组分最可能是滞留在软流圈中的不同地幔柱的物质,也有可能是残留在软流圈中的再循环的地球表层物质.

关键词：地幔柱麦哲伦海山链碳酸盐化地幔热点岩石圈伸展

Investigation of Nanocrystalline Fe-Cu-Nb-Mo-Si-B Alloy

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Journal of Materials Science & Technology 1997年第5期13卷 425-430页

作者： zhang y~*. Shanghai Iron and Steel Research Institute Shanghai 200940 China

The soft magnetic properties are reported for newly-developed nanocrystalline Fe72.7Cu1Nb1.8-Mo2Si13B9.5 and Fe73Cu1Nb1.5Mo2Si13B9.5 The high frequency core losses of the new alloys are as follows: P-3/100K=473 kW.m(-3), P-2/200K=750 kW.m(-3), P-2/500K=3400 kW.m(-3), P-0.5/1000K 680 kW.m(-3), which are clearly lower than those of the early-developed Fe-Cu-Nb-Si-B nanocrystalline alloys and the superior power MnZn ferrite H-7c4 The dependences of core loss on frequency and amplitude magnetic flux density have been analysed. The temperature relations of initial susceptibility have been examined for as-quenched and different annealed Fe72.7Cu1Nb1.8Mo2Si13B9.5 alloy acid interpreted by using the phenomenological theory.

关键词： Mo Fe Si Cu

Attitude control for part actuator failure of agile small satellite

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Acta Mechanica Sinica 2008年第4期24卷 463-468页

作者： J.R.zhang A.Rachid y.zhang Beijing Institute of Technology School of Aerospace Science and Engineering 100081 Beijing China Univercite de Picardie-Jules Veme 80000 Amiens France

The stability and singularity problem of agile small satellite （ASS） with actuator failure is discussed in this paper. Firstly, the three-axis stabilized controller of an ASS is designed, where micro control moment gyros （MCMG＇s） in pyramid configuration （PC） is used as the actuator. By using the same controller and steering law, the control results before and after one gyro fails are compared by simulation. The variation of singular momentum envelope before and after one gyro fails is also compared. The simulation results show that the failure intensively decreases the capacity of output torque, which leads to the emergence of more singular points and the rapid saturation of MCMG＇s. Finally, the parameters of system controller are changed to compare the control effect.

关键词： Micro control moment gyros (MCMG's) · Gyro failure ·Singularity analysis · Agile small satellite

THE HOT DEFORMATION BEHAVIOR AND DyNAMIC RECRySTALLIZATION MODEL OF 35CrMo STEEL

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Acta Metallurgica Sinica(English Letters) 2003年第3期16卷 183-191页

作者： B.zhang H.B.zhang X.y.Ruan y.zhang Department of Plasticity Technology Shanghai Jiao Tong University Shanghai 200030 ChinaDepartment of Materials Science and Engineering Shanghai Institute of Technology Shanghai 200053ChinaDepartment of Plasticity Technology Shanghai Jiao Tong UniversityShanghai 200030ChinaState Key Laboratory for Advanced Metals & MaterialsUniversity of Science and Technology BeliingBeijing 100083 China

The isothermal single-stage compression of 35CrMo structural steel has been carried out by using Gleeble 1500 simulator at the temperature range of 950℃ to 1150℃ and strain rate range of 0.01s-1 to 10s-1. The effect of hot deformation parameters, such as strain rate, deformed temperature and initial grain size on the flow stress behavior was investigated. The activation energy of tested alloy was calculated, which is 378.16kJ/mol; The relationships between the peak stress (σp), the peak stain (εp), the critical strain (εc) and Z parameter were established. The micro structure evolution shows the pre-existing austenite grain boundaries constitute the principal nucleation sites for dynamic recrystallization (DRX), and the initial austenite grain size affects the grain size of DRX slightly. The kinetic mathematical model of DRX of 35CrMo is: XDRX=1-exp(-3.23-2.28) and Ddyn = 2.252× 10Z-0.22.

关键词： dynamic recrystallization deformation activation energy stress/strain curve grain size

Thermal Properties of PHB/PEG Blends

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Journal of Materials Science & Technology 1998年第1期14卷 95-96页

作者： zhang, QQ zhang, y Wang, FJ Liu, LR Wang, C Chinese Acad Med Sci Inst Biomat Engn Tianjin 300192 Peoples R China Peking Union Med Coll Tianjin 300192 Peoples R China Univ Utah Salt Lake City UT 84112 USA

Thermal properties of PHB and PHB/PEG blends were investigated by differential scanning calorimetry (DSC) and melt index (MI) test. DSC thermograms indicate that two components of blend are miscible. From the DSC thermogram, we can also conclude that the melting point of PHB descends with the increased content of PEG, this can improve PHB processing properties. From MI data, we may draw the same conclusion.

关键词： Polyesters

Proper orthogonal decomposition analysis of coherent motions in a turbulent annular jet

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Applied Mathematics and Mechanics(English Edition) 2021年第9期42卷 1297-1310页

作者： y.zhang M.VANIERSCHOT Department of Mechanical Engineering Group T Leuven CampusCelestijnenlaan 300Leuven B-3001Belgium

A three-dimensional incompressible annular jet is simulated by the large eddy simulation(LES)method at a Reynolds number Re=*** time-averaged velocity field shows an asymmetric wake behind the central bluff-body although the flow geometry is *** proper orthogonal decomposition(POD)analysis of the velocity fluctuation vectors is conducted to study the flow dynamics of the wake *** distribution of turbulent kinetic energy across the three-dimensional POD modes shows that the first four eigenmodes each capture more than 1%of the turbulent kinetic energy,and hence their impact on the wake dynamics is *** results demonstrate that the asymmetric mean flow in the near-field of the annular jet is related to the first two POD modes which correspond to a radial shift of the stagnation *** modes 3 and 4 involve the stretching or squeezing effects of the recirculation region in the radial *** addition,the spatial structure of these four POD eigenmodes also shows the counter-rotating vortices in the streamwise direction downstream of the flow reversal region.

关键词： coherent structure proper orthogonal decomposition(POD) turbulent annular jet large eddy simulation(LES)

NEWLy-DEVELOPED AND CHEAP NANOCRySTALLINE Fe-Cu-Nb-Mo-Si-B ALLOyS FOR SWITCHING MODE POWER SUPPLy

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Acta Metallurgica Sinica(English Letters) 1997年第6期10卷 489-494页

作者： zhang, y.Z. Shanghai Iron and Steel Research Inst Shanghai China

The synthetical soft magnetic properties were reported for newly-developed nanocrystalline Fe73.5Cu1Nb0.9 Mo2.1Si13.5B9 and Fe73.5Cu1Nb0.5 Mo2.5Si13.5B9 alloys. The levels of high-frequency losses of the new alloys are P3/100k=612 and 670 kWm-3, P2/200k=880 and 973kWm-3, P2/500k=4300 and 4600 kWm-3, P0.5/1000k=860 and 920 kWm-3, respectively. They are significantly lower than those of the superior power Mn-Zn ferrite H7c4. The dependence of core loss on frequency and amplitude flux density has been analyzed. The practical applications of the new alloys to switching mode power supplies with the output power of 1 and 2kW were reported.

关键词： Boron Copper alloys Electric power systems Magnetic materials Molybdenum alloys Nanostructured materials Niobium alloys Silicon alloys

NUMERICAL MODELING OF DONGZHUANG RESERVOIR ON JING RIVER

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Journal of Hydrodynamics 2001年第2期13卷 68-71页

作者： yang, M. zhang, H.y. zhang, J.H. zhang, H.W. Dept. 5 Beijing Univ. of Aero. and Astron. Beijing 100084 China

The Dongzhuang Reservoir will be constructed on the Jing River, which is laden with the highest sediment concentration in the world. The sediment problem is a key challenge for the reservoir design and management. This paper presents essential data, details of sediment scour and siltation calculated by the numerical modeling based on new fundamental equations. Calculated results prove that the reservoir could preserve long-term storage capacity with the operation was offered by the design department.

关键词： Flow of fluids Mathematical models Sediments Storage (materials)

Diatomic Pd catalyst with conjugated backbone for synergistic electrochemical CO_(2)reduction

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Nano Research 2024年第6期17卷 4850-4855页

作者： Wenxuan zhang Mengran zhang Hongjuan Wang Wen zhang Min zhang MOE International Joint Laboratory of Materials Microstructure Institute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion School of Chemistry and Chemical EngineeringTianjin University of TechnologyTianjin 300384China

Double-site catalysts have attracted widespread attention in the field of electrocatalysis due to their high metal loading,adjustable active centres,and electronic valence ***,the development of bimetallic sites catalysts that coordinate with definite atoms is still in the exploratory ***,we designed and synthesized a bimetallic palladium complex(BPB-Pd_(2))with conjugated *** supported BPB-Pd_(2)was applied to electrochemical CO_(2)reduction reaction(CO_(2)RR)for the first *** as-obtained BPB-Pd_(2)gives an exceptional Faradaic efficiency of CO(FECO)of 94.4%at−0.80 V *** hydrogen electrode(RHE),which is significantly superior to monoatomic palladium catalyst(BPB-Pd1).The density functional theory(DFT)calculations revealed that the essential reason for the outstanding activity of BPB-Pd_(2)toward CO_(2)RR was that the electronic effect between diatomic palladium reduces the free energy change for CO_(2)RR ***,BPB-Pd_(2)exhibits moderate free energy change to form COOH*intermediate,which was beneficial for the generation of CO in CO_(2)RR.

关键词： synthesis electrocatalysis CO_(2)reduction bimetallic palladium complex synergistic catalysis