检索结果-南通市图书馆

Effect of Zn addition on microstructure and mechanical properties of Mg-3Y-2Nd-0.5Zr alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2023年第4期20卷 299-306页

作者： Fei-yu He Wen-xin Hu Li-juan Liu shao-bo ma Wei He State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Baotou 014030Inner MongoliaChina Baotou Research Institute of Rare Earths Baotou 014030Inner MongoliaChina Technical Center of Steel Union Co. Ltd.of Baotou Steel(Group)Corp.Baotou 014010Inner MongoliaChina

The effect of 0.5wt.%Zn addition on the microstructure and mechanical properties of Mg-3Y-2Nd-0.5Zr(WE32)alloy was *** results indicate that WE32-0.5Zn alloy takes 48 h to reach peak hardness after solid solution treatment at 525℃and aging at 200℃,10 h earlier than WE32 alloy,which implies an accelerated aging precipitation kinetics owing to the addition of 0.5wt.%Zn.A large quantity of finerod and rectangular block-like Zn-Zr precipitates in theα-Mg matrix are formed in the WE32-0.5Zn alloy,and numerous needle-likeβ1phases are distributed at both ends of the Zn-Zr precipitates at peak-aged *** peak-aged condition,the ultimate tensile strength considerably increases from 263.2 MPa(WE32)to 309.6 MPa(WE32-0.5Zn),and the elongation dramatically increases from 4.3%(WE32)to 8.9%(WE32-0.5Zn).Theβ’andβ1phases are the main precipitates of the WE32-0.5Zn alloy peak-aged at 200℃.Theβ’andβ1phases easily nucleate at the Zn-Zr precipitates,and theβ1phases are particularly likely to nucleate and grow at the interface between the two ends of the Zn-Zr precipitates,which accelerates aging precipitation kinetics and leads to a shorter time to achieve peak aging.

关键词： Mg-3Y-2Nd-0.5Zr Zn-Zr precipitates microstructure mechanical properties

Effect of Ce on microstructure and mechanical properties of Mg-Zn-Ce magnesium alloys

在线全文

学校读者我要写书评

暂无评论

China Foundry 2023年第4期20卷 271-279页

作者： Hong-fei Wu Wen-xin Hu shao-bo ma Zheng-hua Yang Wei Wang Feng Liu Wei He State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Baotou 014030Inner MongoliaChina Baotou Research Institute of Rare Earths Baotou 014030Inner MongoliaChina

The Mg-6Zn alloy with different contents of Ce was prepared by the gravity casting method,and then the Mg-6Zn-xCe(x=0,0.5,1.0,1.5,wt.%)alloys were extruded at 300℃and 350℃ after solution *** phase constitution and microstructure evolution of Mg-Zn-xCe alloys were analyzed by X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and electron backscattering diffraction(EBSD).Meanwhile,the mechanical properties of the alloy were tested at room *** as-cast alloys,the results show that the main compound in Mg-6Zn alloy is Mg4Zn7 phase,and the main compound is T-(MgZn)12Ce phase after the addition of different amounts of *** microstructure and distribution of second phases are greatly improved after extrusion at 300℃and 350℃.Compared with initial mechanical properties,the strength and elongation increase obviously by means of extrusion at different *** addition,the microstructure after extrusion at 350℃is further analyzed according to EBSD *** results show that rare earth element Ce probably promotes the activation of non-basal slip during the deformation process with the increase of Ce,which reduces the strength of basal texture and thus improves the plasticity of the ***,the increase of grain boundary migration ability leads to the gradual increase of recrystallization grain size and decreases the strength.

关键词： Mg-Zn-Ce extrusion microstructure mechanical properties magnesium alloys

An efficient method for mapping the 12C+12C molecular resonances at low energies

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第8期30卷 77-83页

作者： Xiao-Dong Tang shao-bo ma Xiao Fang Brian Bucher Adam Alongi Craig Cahillane Wan-Peng Tan Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China Idaho National Laboratory Idaho FallsID 83415USA Institute for Structure and Nuclear Astrophysics University of Notre DameNotre DameIN 46556USA 123

The 12C+12C fusion reaction is famous because of its complication of molecular resonances,and it plays an important role in both nuclear structural research and astrophysics. It is extremely difficult to measure the cross sections of 12C+12C fusions at energies of astrophysical relevance because of the very low reaction yields. To measure the complicated resonant structure that exists in this important reaction, an efficient thick target method has been developed and applied for the first time at energies Ec.m.<5.3 MeV. A scan of the cross sections over a relatively wide range of energies can be carried out using only a single beam energy. The result of measurement at Ec.m.=4.1 MeV is compared with results from previous *** method will be useful for searching for potentially existing resonances of 12C+12C in the energy range 1 MeV

关键词： 12C+12C Molecular resonance Thick targetmethod 12C(12C, p)^23Na

A new seamoth species of Pegasus(Syngnathiformes:Pegasidae)from the East China Sea

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2022年第4期43卷 675-678页

作者： Ying-Yi Zhang Rong-Rong Zhang shao-bo ma Shuai-Shuai Liu Qiang Lin Xin Wang CAS Key Laboratory of Tropical marine Bio-resources and Ecology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhouGuangdong 510301China Southern marine Science and Engineering Guangdong Laboratory(Guangzhou) GuangzhouGuangdong 511458China State Key Laboratory of marine Environmental Science/College of the Environment and Ecology Xiamen UniversityXiamenFujian 361102China University of the Chinese Academy of Sciences Beijing 100049China Laboratory for marine Fisheries Science and Food Production Processes Pilot National Laboratory for Marine Science and Technology(Qingdao)QingdaoShandong 266237China

DEAR EDITOR,The Pegasidae family,which includes seven species of seamoths,is widely distributed in the temperate and tropical waters of the Indo-Pacific,ranging from South Africa to *** this study,we describe a new species of seamoth,Pegasus sinensis ***.,based on morphological and molecular characterization of 14 specimens collected from the surrounding waters of Xiamen City,Fujian Province,*** new species differs from closely related *** in both the density and color of spots present on the dorsal and lateral body surfaces.

关键词： Xiamen asi temperate

Opportunities for production and property research of neutron-rich nuclei around N=126 at HIAF

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第6期35卷 101-113页

作者： shao-bo ma Li-Na Sheng Xue-Heng Zhang Shi-Tao Wang Kai-Long Wang Chun-Wang ma Hool-Jin Ong Zhi-Yu Sun Shu-Wen Tang Yu-Hong Yu Xin-Tong Du Xiao-Bao Wei Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Advanced Energy Science and Technology Guangdong Laboratory Huizhou 516000China University of Chinese Academy of Sciences Beijing 100049China College of Physics Henan Normal UniversityXinxiang 453007China Institute of Nuclear Science and Technology Henan Academy of ScienceZhengzhou 450046China Joint-Department for Nuclear Physics Lanzhou University and Institute of Modern PhysicsLanzhou 730000China Research Center for Nuclear Physics Osaka UniversityOsaka 567-0047Japan RIKEN Nishina Center Saitama 351-0198Japan Northwest Normal University Lanzhou 730070China

The study of nuclide production and its properties in the N=126 neutron-rich region is prevalent in nuclear physics and astrophysics *** upcoming High-energy FRagment Separator(HFRS)at the High-Intensity heavy-ion Accelerator Facility(HIAF),an in-flight separator at relativistic energies,is characterized by high beam intensity,large ion-optical acceptance,high magnetic rigidity,and high momentum resolution *** provides an opportunity to study the production and properties of neutron-rich nuclei around N=*** this paper,an experimental scheme is proposed to produce neutron-rich nuclei around N=126 and simultaneously measure their mass and lifetime based on the HFRS separator;the feasibility of this scheme is evaluated through *** results show that under the high-resolution optical mode,many new neutron-rich nuclei approaching the r-process abundance peak around A=195 can be produced for the first time,and many nuclei with unknown masses and lifetimes can be produced with high *** the time-of-flight corrected by the measured dispersive position and energy loss information,the cocktails produced from 208 Pb fragmentation can be unambiguously ***,the masses of some neutron-rich nuclei near N=126 can be measured with high precision using the time-of-flight magnetic rigidity *** indicates that the HIAF-HFRS facility has the potential for the production and property research of neutron-rich nuclei around N=126,which is of great significance for expanding the chart of nuclides,developing nuclear theories,and understanding the origin of heavy elements in the universe.

关键词： HFRS Fragmentation Neutron-rich nuclei around N=126 mass measurement Lifetime

Toward real-time digital pulse process algorithms for CsI(Tl)detector array at external target facility in HIRFL-CSR

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2023年第9期34卷 8-20页

作者： Tao Liu Hai-Sheng Song Yu-Hong Yu Duo Yan Zhi-Yu Sun Shu-Wen Tang Fen-Hua Lu Shi-Tao Wang Xue-Heng Zhang Xian-Qin Li Hai-bo Yang Fang Fang Yong-Jie Zhang shao-bo ma Hooi-Jin Ong Cheng-Xin Zhao Northwest Normal University Lanzhou 730070China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

A fully digital data acquisition system based on a field-programmable gate array(FPGA) was developed for a CsI(Tl) array at the external target facility(ETF) in the Heavy Ion Research Facility in Lanzhou(HIRFL). To process the CsI(Tl) signals generated by γ-rays and light-charged ions, a scheme for digital pulse processing algorithms is proposed. Every step in the algorithms was benchmarked using standard γ and α sources. The scheme, which included a moving average filter, baseline restoration, leading-edge discrimination, moving window deconvolution, and digital charge comparison, was subsequently implemented on the FPGA. A good energy resolution of 5.7% for 1.33-MeV γ-rays and excellent α-γ identification using the digital charge comparison method were achieved, which satisfies CsI(Tl) array performance requirements.

关键词： CsI(Tl)array On-line digital algorithms Moving average filter Moving window deconvolution On-line particle identification algorithms

Isotopic production cross sections of fragmentation residues produced by ^(18)O ions on a carbon target near 260 MeV/nucleon

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第11期46卷 1-6页

作者： Xiao-Dong Xu Ya-Zhou Sun Shi-Tao Wang bo Mei Shu-Ya Jin Xue-Heng Zhang Zhi-Yu Sun Yi-Xuan Zhao Shu-Wen Tang Yu-Hong Yu Duo Yan Fang Fang Yong-Jie Zhang shao-bo ma CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China

The isotopic cross sections of residual nuclei produced in fragmentation reactions of ^(18)O projectiles impinging on a carbon target at energies near 260 MeV/nucleon were measured at the HIRFL facility in Lanzhou(China).A full identification of atomic and mass numbers of fragments was achieved from the determination of their magnetic rigidity,energy loss,and time of *** production cross sections for a dozen of nitrogen,carbon,and boron isotopes were determined with uncertainties below 30% for most of the *** obtained cross sections for N and B isotopes show a rather good agreement with previous experimental data obtained with different projectile *** cross sections for some C isotopes seem to exhibit a dependence on the projectile energy.A comparison of the data and several theoretical model calculations are presented.

关键词： heavy-ion collisions projectile fragmentation isotopic production cross sections

Fragmentation of stable and neutron-rich ^(12-16)C into boron fragments at approximately 240 MeV/nucleon

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2022年第1期46卷 118-123页

作者： Shu-Ya Jin Ya-Zhou Sun Shi-Tao Wang Zhi-Yu Sun Xue-Heng Zhang Zhi-Qiang Chen bo Mei Yi-Xuan Zhao Shu-Wen Tang Yu-Hong Yu Duo Yan Fang Fang Yong-Jie Zhang shao-bo ma Xiang-man Liu Rui Han CAS Key Laboratory of High Precision Nuclear Spectroscopy Institute of Modern PhysicsChinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100080China School of Nuclear Science and Technology Lanzhou UniversityLanzhou 730000China School of Physics and Electrical Engineering Anyang Normal UniversityAnyang 455000China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082China

The elemental fragmentation cross sections of boron fragments produced by stable and neutron-rich^(12-16)C beams with a carbon target were systematically measured at an incident beam energy of approximately 240 MeV/*** measured cross sections were found to increase as the projectile mass number *** observed feature is explained qualitatively based on the abrasion-ablation two-stage reaction model and is compared quantitatively with predictions from various reaction models,including empirical and statistical *** models agree with the measured cross sections within a factor of 2.

关键词： elemental fragmentation cross sections neutron-rich carbon isotopes abrasion-ablation model

Measurement of the^2H(^7Be,^6Li)^3He reaction rate and its contribution to the primordial lithium abundance

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2018年第4期42卷 150-156页

作者： Er-Tao Li Zhi-Hong Li Sheng-Quan Yan Jun Su Bing Guo Yun-Ju Li You-Bao Wang Gang Lian Sheng Zeng Si-Zhe Chen shao-bo ma Xiang-Qing Li Cao He Hui-Bin Sun Wei-Ping Liu China Institute of Atomic Energy Beijing 102413China College of Physics and Energy Shenzhen UniversityShenzhen 518060China Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China

In the standard Big Bang nucleosynthesis （SBBN） model, the lithium puzzle has attracted intense interest over the past few decades, but still has not been solved. Conventionally, the approach is to include more reactions flowing into or out of lithium, and study the potential effects of those reactions which were not previously considered. 7Be（d, 3He）6Li is a reaction that not only produces 6Li but also destroys 7Be, which decays to 7Li, thereby affecting 7Li indirectly. Therefore, this reaction could alleviate the lithium discrepancy if its reaction rate is sufficiently high. However, there is not much information available about the 7Be（d, 3He）6Li reaction rate. In this work, the angular distributions of the 7Be（d, 3He）6Li reaction are measured at the center of mass energies Ecm=4.0 MeV and 6.7 MeV with secondary 7Be beams for the first time. The excitation function of the 7Be（d, 3He）6Li reaction is first calculated with the computer code TALYS and then normalized to the experimental data, then its reaction rate is deduced. A SBBN network calculation is performed to investigate its influence on the 6Li and 7Li abundances. The results show that the 7Be（d, 3He）6Li reaction has a minimal effect on 6Li and 7Li because of its small reaction rate. Therefore, the 7Be（d, 3He）6Li reaction is ruled out by this experiment as a means of alleviating the lithium discrepancy.

关键词： reaction rates primordial lithium abundance big bang nucleosynthesis lithium puzzles