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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

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Current Zoology 2019年第5期65卷 527-534页

作者： ke DENG Wei LIU De-hua WANG State key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijingChina Chengdu Institute of Biology Chinese Academy of SciencesChengduSichuanChina University of Chinese Academy of Sciences BeijingChina

Kin selection theory predicts that individuals should generally behave less aggressively or more amicably towards relatives than ***,how individuals treat conspecifics depends on genetic relatedness but also on the ecological context,which influences the benefits and costs of their *** this study,we used microsatellite DNA markers and behavioral tests to examine the influence of kinship and proximity on the social behavior of Mongolian gerbils Meriones unguiculatus living in different social groups,and whether these effects varied with sex and *** recorded the duration of 4 behavioral categories(investigative,neutral,amicable,and agonistic)during a 10-min pairwise *** found that genetic relatedness had significant effects on the duration of investigative,neutral,and amicable behavior,but not on agonistic *** also found significant interaction effects of relatedness and distance between burrow systems(i.e.,spatial distance)on investigative,neutral,and amicable behavior,which suggests that the effects of kinship on social behavior were restricted by spatial *** interaction effect between sex and relatedness on amicable behavior showed that male gerbils became more intimate with individuals of the same sex that had higher pairwise relatedness than ***,both male and female gerbils enhanced their aggression during the food-hoarding season,but the intensity of these changes was significantly higher in ***,our results suggest that the effects of kinship and spatial proximity on social behavior exhibit sexual or seasonal patterns,thereby implying ecological context-dependent responses to out-group individuals in Mongolian gerbils.

关键词： familiarity kinship Meriones unguiculatus seasonality social behavior

Effect of Cu on Microstructures of Manganese Steel by EDXA and SEM

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Journal of Materials Science & Technology 2007年第3期23卷 307-311页

作者： Xinhua ChEN Junhua DONG Enhou hAN Wei ke Environmental Corrosion Center Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

In order to investigate the distribution of Cu and Mg, and the effect of Cu on the microstructure of steels, manganese steels containing various Cu contents were annealed at 1260, 1100 and 1000℃, respectively, for I h and subsequently cooled to room temperature in the furnace to simulate the pre-rolling anneal. The results indicate that Cu is not microscopically segregated in the annealed steels. The scanning electron microscopy （SEM） observation shows that the main microstructure consist of ferrite and pearlite; the percentage of pearlite in the steels increases with increasing Cu content. The grain size reduces with the decrease of the annealing temperature. The results of energy dispersive X-ray analysis （EDXA） suggest that Cu content in pearlite is higher than that in ferrite, demonstrating that the microstructure-segregation of Cu occurred. however, the cast specimens show that Cu content in MnS and S-rich phases is high. In addition, Cu of 0.2%-0.4% could improve the distribution of MnS and S-rich inclusions. The optimal Cu content in steels and the optimal annealing temperature between 1100-1200℃ were determined.

关键词： Manganese steels Copper-alloying Annealing Energy dispersive X-ray analysis (EDXA) Scanning electron microscopy (SEM)

A mosquito mouthpart-like bionic neural probe

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Microsystems & Nanoengineering 2023年第4期9卷 77-90页

作者： Yu Zhou huiran Yang Xueying Wang heng Yang ke Sun Zhitao Zhou Liuyang Sun Jianlong Zhao Tiger h.Tao Xiaoling Wei State key Laboratory of Transducer Technology Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences200050 ShanghaiChina School of Graduate Study University of Chinese Academy of Sciences100049 BeijingChina 2020 X-Lab Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences200050 ShanghaiChina Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences100049 BeijingChina Center for Excellence in Brain Science and Intelligence Technology Chinese Academy of Sciences200031 ShanghaiChina Neuroxess Co. Ltd.(Jiangxi)330029 NanchangJiangxiChina Guangdong Institute of Intelligence Science and Technology Hengqin519031 ZhuhaiGuangdongChina Tianqiao and Chrissy Chen Institute for Translational Research ShanghaiChina

Advancements in microscale electrode technology have revolutionized the field of neuroscience and clinicalapplications by offering high temporal and spatial resolution of recording and stimulation. Flexible neural probes, withtheir mechanical compliance to brain tissue, have been shown to be superior to rigid devices in terms of stability andlongevity in chronic recordings. Shuttle devices are commonly used to assist flexible probe implantation;however, theprotective membrane of the brain still makes penetration difficult. hidden damage to brain vessels duringimplantation is a significant risk. Inspired by the anatomy of the mosquito mouthparts, we present a biomimeticneuroprobe system that integrates high-sensitivity sensors with a high-fidelity multichannel flexible electrode *** customizable system achieves distributed and minimally invasive implantation across brain regions. Mostimportantly, the system’s nonvisual monitoring capability provides an early warning detection for intracranial softtissues, such as vessels, reducing the potential for injury during implantation. The neural probe system demonstratesexceptional sensitivity and adaptability to environmental stimuli, as well as outstanding performance in postoperativeand chronic recordings. These findings suggest that our biomimetic neural-probe device offers promising potential forfuture applications in neuroscience and brain-machine interfaces.

关键词： neural implantation recording

Genetic Variation in Rhizome Lotus(Nelumbo nucifera ***) Germplasms from China Assessed by RAPD Markers

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Agricultural Sciences in China 2009年第1期8卷 31-39页

作者： AN Na GUO hong-bo ke Wei-dong College of Life Science Northwest A ＆ F University Yangling 712100 P.R.China National Garden of Aquatic Vegetable Wuhan Institute of Vegetable Science Wuhan 430065 P.R China

To estimate genetic variation in rhizome lotus （Nelumbo nucifera Gaertn. ssp. nucifera） germplasms in China, a total of 94 rhizome lotus germplasms collected from 18 provinces in China were assessed. The RAPD （randomly amplified polymorphic DNA） marker was employed. The selected 17 random primers detected 139 polymorphic alleles out of a total 207 （67.15%）. Nei＇s gene diversity statistics and region differentiation parameters indicated that all germplasms had a relatively high level of genetic diversity with ne = 1.3202, h = 0.1937, I= 0.2982 and the gene flow among all regions was Nrn = 5.5742. The UPGMA dendrogram clustered all 94 germplasms into two clusters： One contained eight commercial cultivars and major landraces, and the other included the wild and some special landraces from five regions, and the PCA analysis exhibited the similar result. Those germplasms from southwestern and eastern China had higher genetic diversity than those from the southern, northern and central China. Predominant proportion of genetic variation （95.61%） was found significant within rather than among （4.39%） regions, as revealed by AMOVA analysis. The data analysis also revealed that the genetic diversity of rhizome lotus germplasms among different regions is positively related to their geographic distances, though it is ambiguous to find the trend from the UPGMA dendrogram and the PCA analysis. A relatively high genetic diversity and gene flow resided in the root lotus germplasms; about 96% of the variation was found within region; accessions from southwest and eastern China have higher genetic diversity than those from the southern, northern and central China.

关键词： germplasm genetic diversity lotus accessions N. nucifera Gaertn. RAPD

Structure and properties of an ultra-high strength 7xxx aluminum alloy contained Sc and Zr

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Journal of University of Science and Technology Beijing 2008年第3期15卷 276-279页

作者： Xiaoyuan Dai Changqing Xia Xiaomin Peng ke Ma School of Materials Science and Engineering Central South University Changsha 410083 China School of Materials Science and Engineering Changsha University of Science and Technology Changsha 410076 China

An ultra-high strength aluminum alloy was produced by casting and then extruded to rods. The effect of heat treatment on the microstructure and mechanical properties of the alloy was investigated. After single ageing （120℃, 24 h）, the tensile strength was 812.4 MPa and the elongation was 6.2%. After retrogression reaging （RRA）, the tensile strength was 751.2 MPa and the elongation was 6.4%. The strengthening mechanism is considered as fine grain strengthening, substructure strengthening and dispersion strengthening by Al3（Sc, Zr）.

关键词： aluminum alloy scandium zirconium microstructure mechanical properties strengthening mechanism

Pinches-Induced Transport Reduction in Reversed Shear/Optimized Shear Tokamak Plasmas

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Chinese Physics Letters 1999年第9期16卷 662-664页

作者： QIU Xiao-ming WANG Ai-ke Southwestern Institute of Physics (P.O.Box 432)Chengdu 610041

The analytical formulas for anomalous particle and ion thermal diffusivities,Dte and xti,are derived on the basis of the two-fluid equations of our previous paper[***.15(1998)721].The two formulas involve five factors:(reversed/optimized)magnetic shear LB(r),E x B sheared velocity VE(r),where E is from the gradient of the ion pressure Pi,and the three ways of coupling between them,L-1B(dVE/dr),L-1B VE,and ***,where k is the LB-dependent *** is found that the five factors can produce turbulent particle-and heat-pinch,i.e.,Dtehe core region of tokamaks,and hence the effective particle and ion thermal diffusivities,Deeff and xieff,reduce significantly in that *** numerical results for Deeff and xieff are in good agreement with experimental values.

关键词： Shear particle reversed

Corrosion Behavior of X52 Anti-h_2S Pipeline Steel Exposed to high h_2S Concentration Solutions at 90℃

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Journal of Materials Science & Technology 2014年第5期30卷 504-510页

作者： Meng Liu Jianqiu Wang Wei ke En-hou han State key Laboratory for Corrosion and Protection Institute of Metal ResearchChinese Academy of Sciences

Initial corrosion kinetics of X52 anti-h2S pipeline steel exposed to 90 ℃/1.61 MPa h2S solutions was investigated through high temperature and high pressure immersion tests. Corrosion rates were obtained based on weight loss calculation. The corrosion products were analyzed by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and electron probe micro-analysis （EPMA）. The initial corrosion kinetics was found to obey the exponential law. With increasing immersion time, the main corrosion products changed from iron-rich mackinawite to sulfur-rich pyrrhotite. The corrosion films had two layers： an inner fine-grained layer rich in iron and an outer columnar-grained layer rich in sulfur. The corrosion film formed through the combination of outward diffusion of Fe2＋ ions and inward diffusion of hS^- ions. The variation of the corrosion products and compaction of the corrosion layer resulted in a decrease in the diffusion coefficient with increasing immersion time. The double-layered corrosion film formed after long time immersion acted as an effective barrier against diffusion.

关键词： h2S corrosion X52 anti-h2S pipeline steel high temperature Iron sulfide

Model for heat Pinch in Reversed Magnetic Shear Tokamak Plasmas

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Chinese Physics Letters 1998年第10期15卷 721-723页

作者： QIU Xiao-ming WANG Ai-ke Southwestern Institute of Physics P.O.Box 432Chengdu 610041

A simple model is proposed to explain the recent experiment in TFTR and the more recent one in *** the model the significant reduction of effective thermal diffusivities of ions and electrons(xieff and xeeff)is attributed to the inward flows of drift wave energy,induced by the synergistic effects of the reversed magnetic shear and E X B velocity shear,where E is due to ion pressure *** results demonstrate the predictions of the present model,in particular,the numerical results for x_(i)^(eff) are in good agreement with experimental trents.

关键词： reversed Plasma synergistic