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| 1 | Designing new work-hardenable ductile Ti-based multilayered bulk metallic glass composites with ex-situ and in-situ hybrid strategy显示文摘To overcome the trade-off between the devisable micro structure and the excellent tensile ductility of bulk metallic glass composites(BMGCs),a novel ex-situ and in-situ hybrid strategy is successfully proposed to design a series of the work-hardenable ductile Ti-based multilayered BMGCs(ML-BMGCs).The asprepared ML-BMGCs,consisting of α-phases,β-phases and amorphous phases,exhibit a controllable multilayered structure of the Ti layers and the amorphous layers with alternative distribution.The size and volume fraction of the crystalline phases are tuned by Nb microalloying.It is found that the ML-BMGCs possess a suitable size and volume fraction of the crystalline phases when Nb microalloying content are5%(at.) or 8%(at.),and they obtain an optimum combination of the specific strength of 243 MPa g kg-1 or 216 MPa g kg-1,and tensile plasticity of 4.33%±0.1 % or 5.10%±0.1%.The deformation mechanism of the as-prepared ML-BMGCs during tension is also revealed.The ex-situ Ti layers and in-situ dendrites together effectively serve as absorbers to suppress the propagation of shear bands and multiply shear bands.And the defo rmation of ex-situ α-Ti phases by dislocation slip and the transformation from in-situ metastable β-Ti phase to orthorhombic α-Ti during tension impart significant work-hardening capability to the ML-B MGCs.The present study provides a guidance of developing novel high-performance BMGCs with a controllable micro structure. | Shifeng Lin Zhengwang Zhu Shaofan Ge Long Zhang Dingming Liu Yanxin Zhuang Huameng Fu Hong Li Aimin Wang Haifeng Zhang | 2020 | Journal of Materials Science & Technology2020，47，15： | 1 |
| 2 | High-temperature Mechanical Properties and Dynamic Recrystallization Mechanism of in situ Silicide-reinforced MoNbTaTiVSi Refractory High-entropy Alloy Composite显示文摘The hypoeutectic composite material composed of BCC phase and in situ precipitated Ti_(5)Si_(3) was prepared by adding Si into MoNbTaTiV high-entropy alloy.The obvious oriented in situ Ti_(5)Si_(3) phase formed eutectic phase with BCC phase in the inter-dendritic area,which leads to excellent properties of the composite.The alloy exhibits ultra-high yield stress of 718 MPa at 1200℃ and obvious compression plasticity.After reaching the maximum strength,dynamic recovery(DRV)and dynamic recrystallization(DRX)caused soften phenomena.The DRX mechanism of the dual-phase eutectic structure is analyzed by electron backscatter diffraction.The DRX of the BCC phase conforms to the discontinuous DRX and continuous DRX mechanisms,while the Ti_(5)Si_(3) phase has a geometric DRX mechanism in addition to the above two mechanisms.The high performance of this composite has enough potential high-temperature applications such as nuclear and aero engine. | Shaofan Ge Shifeng Lin Huameng Fu Long Zhang Tieqiang Geng Zhengwang Zhu Zhengkun Li Hong Li Aimin Wang Hongwei Zhang Haifeng Zhang | 2022 | Acta Metallurgica Sinica(English Letters)2022，35，10： | 1 |
| 3 | The allocation between egg size and clutch size depends on local nest survival rate in a mean of bet-hedging in a shorebird显示文摘Background:The allocation of resources between offspring size and number is a central question of life-history theory.Although several studies have tested the existence of this trade-off,few studies have investigated how environmental variation influences the allocation of resources to offspring size and offspring number.Additionally,the relationship between population dynamics and the offspring size and number allocation is far less understood.Methods:We investigate whether resource allocation between egg size and clutch size is influenced by the ambient temperature and whether it may be related to apparent nest survival rate.We measured 1548 eggs from 541 nests of two closely related shorebird species,the Kentish Plover(Charadrius alexandrinus)and the White-faced Plover(C.dealbatus)in China,in four populations that exhibit contrasting ambient environments.We weighed females,monitored nest survival,and calculated the variance of ambient temperature.Results:Although we found that egg size and clutch size were all different between the four breeding populations,the reproductive investment(i.e.total clutch volume)was similar between populations.We also found that populations with a high survival rate had relatively larger eggs and a smaller clutch than populations with a low nest survival rate.The latter result is in line with a conservative/diversified bet-hedging strategy.Conclusions:Our findings suggest that plovers may increasing fitness by investing fewer,larger or many,small according local nest survival rate to make a similar investment in reproduction,and thereby may have an impact on population demography. | Zitan Song Xin Lin Pinjia Que Naerhulan Halimubieke Qin Huang Zhengwang Zhang Tamás Székely Yang Liu | 2020 | Avian Research2020，11，4： | 1 |
| 4 | Zigzag magnetic order in a novel tellurate compound Na_(4-δ)NiTeO_6 with S=1 chains显示文摘Na_(4-δ)Ni Te O_(6) is a rare example in the transition-metal tellurate family of realizing an S=1 spin-chain structure.By performing neutron powder diffraction measurements,the ground-state magnetic structure of Na_(4-δ)Ni Te O_(6) is determined.These measurements reveal that below T_N~6.8(2)K,the Ni^(2+) moments form a screwed ferromagnetic(FM)spin-chain structure running along the crystallographic a axis but these FM spin chains are coupled antiferromagnetically along the b and c directions,giving rise to a magnetic propagation vector of k=(0,1/2,1/2).This zigzag magnetic order is well supported by first-principles calculations.The moment size of Ni^(2+) spins is determined to be 2.1(1) μ_(B) at 3 K,suggesting a significant quenching of the orbital moment due to the crystalline electric field(CEF)effect.The previously reported metamagnetic transition near H_(c)~0.1 T can be understood as a field-induced spin-flip transition.The relatively easy tunability of the dimensionality of its magnetism by external parameters makes Na_(4-δ)Ni Te O_(6)a promising candidate for further exploring various types of novel spin-chain physics. | Cheng Su Xu-Tao Zeng Yi Li Nvsen Ma Zhengwang Lin Chuandi Zhang Chin-Wei Wang Ziyu Chen Xingye Lu Wei Li Xian-Lei Sheng Wentao Jin | 2022 | Science China(Physics,Mechanics & Astronomy)2022，65，9： | 0 |
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