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Interface dominated deformation transition from inhomogeneous to apparent homogeneous mode in amorphous/amorphous nanolaminates

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journal of Materials Science & Technology 2022年第4期99卷 178-183页

作者： Z.Q.chen M.c.Li j.S.cao F.c.Li S.w.Guo B.A.Sun H.B.Ke w.H.wang Songshan Lake Materials Laboratory Dongguan 523808PR China Institute of Physics Chinese Academy of SciencesBeijing 100190PR China Institute of Materials Engineering Nanjing UniversityNantong 226019PR China School of Physics Science and Technology Xinjiang UniversityXinjiang 830046PR China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049PR China State Key Laboratory for Mechanical Behavior of Material Xi'an Jiaotong UniversityXi’an 710049PR China

The amorphous/amorphous nanolaminates(A/ANLs)have aroused great attentions owing to their tunable structure and enhanced mechanical ***,the plastic deformation mechanism of A/ANLs have yet been ***,we systematically examined the mechanical properties and deformation behavior of series of NiNb/ZrcuNi Al A/ANLs via nanoindentaion *** was found that both the amount and morphology of amorphous/amorphous interface(A/AIs)played crucial roles in the plastic deformation of A/*** and straighter A/AIs facilitated multiple shear banding deformation,of which the hardness increased with decreasing layer thickness,as the A/AIs hindered the propagation of shear bands(SBs).whilst,more and wavier A/AIs promoted homogeneous deformation,of which the hardness stayed at a much lower value and was relatively irrelevant with the layer thickness,for the promoted activation of shear transformation zones by A/*** results provide guidance for modifying the mechanical properties of amorphous alloys with interface engineering design.

关键词： Amorphous alloys Nanolaminates Shear bands Hardness Interface

Sea Nine 211 as antifouling biocide: A coastal pollutant of emerging concern

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journal of Environmental Sciences 2017年第11期29卷 68-79页

作者： Lianguo chen james c.w.Lam State Key Laboratory in Marine Pollution City University of Hong Kong Department of Science and Environmental Studies The Education University of Hong Kong

Sea Nine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one（DcOIT） being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as an environmentally acceptable antifoulant mainly due to its claimed rapid degradation in marine environment. However, increasing researches document varying degradative kinetics in different environments, proving that Sea Nine 211 is actually not degraded equally fast around the world（half-life between〈 1 day and 13.1 days）. Large-scale application of Sea Nine 211 in antifouling coatings has also caused global contamination of marine environment in various compartments. For example, accumulation of Sea Nine 211 is detected as high as 3700 ng/L in Spanish seawater and 281 ng/g dry weight in Korean sediment. considering that Sea Nine 211 is highly toxic against non-target marine organisms, environmental risk assessment finds that most marine organisms are endangered by Sea Nine 211 in worst-case scenario. Its endocrine disrupting and reproductive impairing effects at environmentally worst-case concentrations further constitute a long-term threat to the maintenance of population ***, in the light of the varying degradability, environmental pollution and high toxicity, especially the endocrine disruption, Sea Nine 211 as an antifouling agent is likely to cause non-negligible damages to the marine ecosystem. There is an urgency to perform a systematic ecological risk assessment of Sea Nine 211 to prevent the potential impacts on the health of marine environment. A regular monitoring also becomes necessary to place the usage of antifouling biocides under control.

关键词： Sea Nine 211 Antifouling agent Degradation Environmental occurrences Ecological risks Endocrine disruption

control of dislocation density maximizing precipitation strengthening effect

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journal of Materials Science & Technology 2022年第32期127卷 133-143页

作者： c.Xu w.j.Dai Y.chen Z.X.Qi G.Zheng Y.D.cao j.P.Zhang c.c.Bu G.chen MIIT Key Laboratory of Advanced Metallic and Internetallic Materials Technology Engineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

The strength-ductility trade-off has been the most challenging problem for structural metals for *** strengthening is an ideal approach to enhance the strength without significantly sacrificing the *** nanoprecipitates have been successfully acquired by nanostructural design,but the number density of nanoprecipitates cannot be further *** attempted to enhance number density by introducing highly potent nucleation sites(e.g.,dislocations).However,there remains controversy over the influence of dislocations on the nucleation and growth of coherent nanoprecipitates with minimized nucleation ***,cu-rich nanoprecipitates in an HSLA steel,as a typical type of coherent nanoprecipitates,are *** combining analytical calculation and experiments,we show that dislocations are harmful for the formation of large numbered cu-rich nanoprecipitates in a certain density *** dislocations deprive solute atoms which decrease homogenous precipitation that cannot be compensated by the increase in heterogeneous *** such circumstance,cu-rich nanoprecipitates have smaller number density but larger size and higher fraction of incoherent structures due to rapid Ostwald *** a result,by controlling dislocation density,the yield strength is increased by 24%without obvious loss in ductility as compared with traditional solution-quench-age *** work would help to optimize composition and processing routes that fully exploit the nanoprecipitation strengthening effect.

关键词： cu-rich nanoprecipitates crystallographic defects Nucleation Structural transformation Ostwald ripening

Improvement of coercivity and corrosion Resistance of Nd-Fe-B Sintered Magnets with cu Nano-particles Doping

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journal of Materials Science & Technology 2012年第10期28卷 927-930页

作者： c.Sun w.Q.Liu H.Sun M.Yue X.F.Yi j.w.chen college of Materials Science and Engineering Beijing University of TechnologyBeijing 100124China Earth-panda Advance Magnetic Material co. Ltd.Anhui 231500China

Nd-Fe-B permanent magnets with a small amount of cu nano-particles doping have been prepared by con-ventional sintered method. Effects of cu content on magnetic properties, corrosion resistance, and oxidation properties of the magnets have been studied. It shows that the coercivity rises gradually, while the remanence decreases simultaneously with increasing cu doping amount. Microstructure observation reveals that cu ele- ment enriches mainly the Nd-rich phase. Autoclave test results show that the corrosion rate of the magnets decreases with increasing cu content. After oxidation, the maximum energy product loss of the magnets with 0 and 0.2 wt% cu nano-particles doping are 6.13% and 0.g9%, respectively. Therefore, it is concluded that cu nano-particles doping is a promising way to enhance the coercivity and corrosion resistance of sintered Nd-Fe-B magnets.

关键词： Nd-Fe-B cu nano-particles coercivity corrosion resistance Oxidation

Helicity Amplitude Analysis of η_c Decays into Hyperon-Antihyperon Pairs

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communications in Theoretical Physics 2009年第6期51卷 1091-1094页

作者： pang cai-Ying PING Rong-Gang Institute of High Energy Physics Chinese Academy of Sciences P.O. Box 918（1） Beijing 100049 China college of Physics and Electronic Engineering Guangxi Normal University Guilin 541004 China Liuzhou High School Liuzhou 545006 China

The helicity amplitudes for the processes of e^＋e^- →j/ψ→γηc→γYY（Y： hyperon） are presented, together with the joint angular distributions for ηc decays into ∧∧,∑^0 ∑^0, and [1]-[1]＋. The sensitivities to measure the hyperon decay parameters in these decays are evaluated based on the helicity amplitudes. The prospects to test the Bell inequality in experiment using the decay of ηc→∧∧ are discussed.

关键词： ηc helicity amplitude hyperon decay parameter Bell inequality

Male contraception:prospects for the new millennium

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Asian journal of Andrology 2000年第1期2卷 3-12页

作者： w.M.Hair F.c.w.wu Department of Medicine University of Manchester Manchester MI3 9WL UKDepartment of Medicine University of Manchester Manchester MI3 9WL UK

Effective regulation of human fertility has global consequences in terms of resource depletion, pollution and pover-ty. current family planning services predominantly target a female clientele with few significant developments in malefertility regulation for over a century. The last two decades have witnessed a gathering interest, initially from the scien-tific community, and laterally from industry, in the development of safe, reliable, reversible methods of contraceptionfor men. This review summarises the methods of male fertility regulation which are currently available and critically ex-amines the published data on novel developments in male hormonal contraception which offer the potential of improvedcontraceptive choice for all in new millennium. (Asian j Androl 2000; 2: 3 - 12)

关键词： contraception male contraceptive agents male contraceptive devices gonadotropins testosterone androgen

MOLEcULAR DESIGN OF LIGHT EMITTING POLYMERS

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chinese journal of Polymer Science 2000年第3期18卷 227-237页

作者： j.w.Yu j.K.Kim j.MHong Y.c.Kim H.N.cho D.Y.Kim c.Y.Kim Polymer Materials Laboratory Korea Institute of Science and TechnologyP.O.Box 131CheongryangSeoul 130-650.Korea

Fluorene-based alternating and statistical copolymers were synthesized by employing reaction methods of wittig,Heck and *** copolymers were classified into three groups with the photoluminescence(PL)emission maxima at420,475 and 500 nm,*** copolymers with two chromophores having PL emission maxima at 420 and475 nm emitted light with the emission maximum at 475 nm on photoexcitation at 365 nm and improved the quantumefficiency by the energy ***,the intramolecular energy transfer was inefficient compared to the intermolecularenergy transfer when the two chromophores were apart from each other in the range of the Forster critical ***-pyridinedivinylene alternating copolymer was synthesized by the wittig reaction and found to have physical,electronic andelectrochemical properties of the individual units *** double-layered light emitting diode(LED)with the statisticalcopolymer as an emitting layer and the pyridine-containing copolymer as an electron transporting-hole blocking layer,whichwere sandwiched between ITO and Al,displayed a quantum efficiency of 0.1%.

关键词： Light emitting polymers

Multiple ballistic impacts on 2024-T4 aluminum alloy by spheres:Experiments and modelling

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journal of Materials Science & Technology 2021年第35期94卷 164-174页

作者： j.c.cheng S.P.Zhao D.Fan H.w.chai S.j.Ye c.Li S.N.Luo Y.cai j.Y.Huang School of Materials Science and Engineering Southwest Jiaotong UniversityChengduSichuanP.R.China The Peac Institute of Multiscale Sciences ChengduSichuanP.R.China

Multiple ballistic impacts are carried out on a 2024-T4 aluminum alloy by spherical steel projectiles(5-mm diameter)at~400 m s^(-1),to investigate its dynamic deformation and *** ballistic impact process is captured with high-speed *** samples are characterized with optical imaging,three-dimensional laser scanning,microhardness testing and electron backscatter *** increasing number of impacts,crater diameter increases slightly,but crater depth and crater volume increase significantly,and strain accumulation leads to microhardness increase *** parameters all follow power-law relations with the number of ***-like deformation bands and macroscopic deformation twins are produced by impact as a result of spontaneous dislocation self-pinning under high strain rate,large shear *** multiple impacts,shear strain accumulation in the arc-shaped region of the crater induces deformation twinning when it exceeds a critical value(~1.1-1.6).It is highly possible that the deformation twins are related to deformation bands,since they both share one set of the{111}pole with the initial matrix grain.A finite element method model is optimized to reproduce experimental observations and interpret deformation mechanisms.

关键词： 2024Al-T4 alloy Multiple impacts Twin-like deformation band Deformation twinning Finite element method

Mechanosynthesis and mechanochemical treatment of bismuth-doped vanadium phosphorus oxide catalysts for the partial oxidation of n-butane to maleic anhydride

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journal of Natural Gas chemistry 2008年第3期17卷 232-237页

作者： Y. H. Taufiq-Yap Y.c. wong Y. Kamiya w.j. Tang Putra center for catalysis Science and Technology Department of Chemistry Faculty of Science Universiti Putra Malaysia 43400 UPM Serdang Selangor Darul Ehsan Malaysia Graduate School of Environmental Science Hokkaido Universit3 Sapporo 060-0810 Japan

Three Bi-doped vanadyl pyrophosphate catalysts were prepared via dihydrate route （VPD method）, which consisted of different preparation methods including mechanosynthesis, mechanochemical treatment, and the conventional reflux method. The catalysts produced by the above three methods were characterized by x-ray diffraction （XRD）, scanning electron microscopy （SEM）, and temperature programmed reduction （TPR）. catalytic evaluation for the partial oxidation of n-butane to maleic anhydride （MA） was also carried out. The XRD patterns of all the Bi-doped catalysts showed the main peaks of pyrophosphate phase. Lower intensity peaks were observed for the mechanochemically treated Bi-doped catalyst （VPDBiMill） with two additional small peaks corresponding to the presence of a small amount of V5＋ phase. The TPR profiles showed that the highest amount of active oxygen species, i.e, V4＋–O- pair, responsible for n-butane activation, was removed from VPDBiMill. Furthermore, from the catalytic test results, the graph of selectivity to MA as a function of the conversion of n-butane demonstrated that VPDBiMill was the most selective catalyst. This suggests that the mechanochemical treatment of vanadium phosphate catalyst （VPDBiMill） is a potential method to improve the catalytic properties for the partial oxidation of n-butane to maleic anhydride.

关键词： mechanosynthesis mechanochemical treatment bismuth vanadyl pyrophosphate