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Creep Behavior and Microstructure Evolution of Sand–Cast Mg–4y.2.3Nd–1Gd–0.6Zr Alloy.Crept at 523–573 K

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Journal of Materials Science & Technology 2017年第1期33卷 79-89页

作者： y.H.Kang H.y.n R.S.chen The Group of Magnesium Alloy. and Their Applications Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China University.of the Chinese Academy.of Sciences Beijing 100049China

High temperature tensile-creep behavior of Mg-4y.2.3Nd-IGd-O.6Zr （wt%, WE43（T6）） alloy.at 523- 573 K was investigated. The creep stress exponent is equal to 4.6, suggesting the underly.ng dislocation creep mechanism. The activation energy.is （199 _＋ 23） kJ/mol, which is higher than that for self- diffusion in Mg and is believed to be associated with precipitates coarsening or cross slip. The creep mechanism is further suggested to be dislocation climb at 523 K, while a cross slip at 573 K is possible. The metastable 13＇ and ~]1 phases in the WE43（T6） alloy.were relatively.thermal stable at 523 K and could be effective to hinder the dislocation climb, which contributed to its excellent creep resistance. However, at 573 K it readily.transforms into equilibrium/3e phase and coarsens within two hours, thereby.causing a decrease of creep resistance. In addition, precipitate free zones approximately.normal to applied stress direction （directional PFZs） developed during the creep deformation, especially.at 573 K. Those zones became preferential sites to nucleate, extend and connect microcracks and cavities, which lead to the intergranular creep fracture. Improving the thermal stability.of precipitates or introducing thermally.stable fine plate-shaped precipitates on the basal planes of Mg matrix could enhance the high temperature creep resistance.

关键词： WE43 alloy Creep PFZs Precipitate Fracture

Plasma enhanced diamond deposition on steel and Si substrates

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Acta Metallurgica Sinica(English Letters) 2009年第5期22卷 321-329页

作者： y.S. Li y. Tang Wo chen Q. y.ng C.Xiao A. Hirose Plasma Phy.ics Laboratory University of Saskatchewan Saskatoon SK S7N 5E2 Canada Department of Mechanical Engineering University of Saskatchewan Saskatoon S7N 5A9 Canada

Diamond growth on Fe-Cr-Al-Si steel and Si substrates was comparatively.investigated in microwave plasma enhanced chemical vapor deposition （MPCVD） reactor with different deposition parameters. Adherent nanocry.talline diamond films were directly.deposited on this steel substrate under a ty.ical deposition condition, whereas microcry.talline diamond films were produced on Si wafer. With increasing CH4 concentration, reaction pressure, or the total gas flow rate, the quality.of nanocry.talline diamond films formed on Fe-Cr-Al-Si substrates is gradually.deteriorated in terms of density.and adhesion. This impaired diamond quality.on steels is primarily.associated with a combined effect by.the substrate composition and the specific process conditions that favor excessive nucleation of diamond.

关键词： Plasma CVD Diamond film Steel Si

Graphene Aerogel Composites with Self‑Organized Nanowires‑Packed Honey.omb Structure for Highly.Efficient Electromagnetic Wave Absorption

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Nano-Micro Letters 2025年第2期17卷 533-547页

作者： Xiao y.u Huiy.ng Ouy.ng Ruixiang Deng Qiuqi Zhang Zhenzhong Xing Xiaowu chen Qingliang Shan Jinshan y.ng Shaoming Dong State Key.Laboratory.of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Key.Laboratory.of Inorganic Coating Materials CAS Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Structural Ceramics and Composites Engineering Research Center Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050People’s Republic of China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China School of Phy.ical Science and Technology ShanghaiTech UniversityShanghai 201210People’s Republic of China School of Materials Science and Engineering Zhejiang Sci-Tech UniversityHangzhou 310018People’s Republic of China University.of Chinese Academy.of Sciences Beijing 100039People’s Republic of China

With vigorous developments in nanotechnology.the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave ***,a hierarchical porous structure and composite heterogeneous interface are constructed successfully.to optimize the electromagnetic loss *** macro–micro-sy.ergistic graphene aerogel formed by.the ice template‑assisted 3D printing strategy.is cut by.silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene *** unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric ***,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 ***,rely.ng on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.

关键词： Hierarchical porous structure Interface High-temperature resistance Graphene aerogel composites Electromagnetic wave absorption

Computational Analy.is of Drought Stress-Associated miRNAs and miRNA Co-Regulation Network in Phy.comitrella patens

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Genomics,Proteomics & Bioinformatics 2011年第Z1期 37-44页

作者： Jake y. chen Department of Computer & Information Science Purdue University IN 47907 USA Indiana Center for Sy.tems Biology.and Personalized Medicine IN 46202 USA School of Informatics Indiana University-Purdue University Indianapolis IN 46202 USA

miRNAs are non-coding small RNAs that involve diverse biological processes. Until now, little is known about their roles in plant drought resistance. Phy.comitrella patens is highly.tolerant to drought; however, it is not clear about the basic biology.of the traits that contribute P. patens this important character. In this work, we discovered 16 drought stress-associated miRNA (DsAmR) families in P. patens through computational analy.is. Due to the possible discrepancy.of expression periods and tissue distributions between potential DsAmRs and their targeting genes, and the existence of false positive results in computational identification, the prediction results should be examined with further experimental validation. We also constructed an miRNA co-regulation network, and identified two network hubs, miR902a-5p and miR414, which may.play.important roles in regulating drought-resistance traits. We distributed our results through an online database named ppt-miRBase, which can be accessed at http://***/pptiRBase/***. Our methods in finding DsAmR and miRNA co-regulation network showed a new direction for identify.ng miRNA functions.

关键词： miRNA drought stress co-regulation network Phy.comitrella patens

Characteristic changes in astrocy.e properties during astrocy.e-to-neuron conversion induced by.NeuroD1/Ascl1/Dlx2

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Neural Regeneration Research 2025年第6期20卷 1801-1815页

作者： Qing He Zhen Wang y.chen Wang Mengjie Zhu Zhile Liang Kanghong Zhang y.ge Xu Gong chen GHM Institute of CNS Regeneration Jinan UniversityGuangzhouGuangdong ProvinceChina

Direct in vivo conversion of astrocy.es into functional new neurons induced by.neural transcription factors has been recognized as a potential new therapeutic intervention for neural injury.and degenerative disorders. However, a few recent studies have claimed that neural transcription factors cannot convert astrocy.es into neurons, attributing the converted neurons to pre-existing neurons mis-expressing transgenes. In this study. we overexpressed three distinct neural transcription factors––NeuroD1, Ascl1, and Dlx2––in reactive astrocy.es in mouse cortices subjected to stab injury. resulting in a series of significant changes in astrocy.e properties. Initially. the three neural transcription factors were exclusively.expressed in the nuclei of astrocy.es. Over time, however, these astrocy.es gradually.adopted neuronal morphology. and the neural transcription factors was gradually.observed in the nuclei of neuron-like cells instead of astrocy.es. Furthermore,we noted that transcription factor-infected astrocy.es showed a progressive decrease in the expression of astrocy.ic markers AQP4(astrocy.e endfeet signal), CX43(gap junction signal), and S100β. Importantly. none of these changes could be attributed to transgene leakage into preexisting neurons. Therefore, our findings suggest that neural transcription factors such as NeuroD1, Ascl1, and Dlx2 can effectively.convert reactive astrocy.es into neurons in the adult mammalian brain.

关键词： aquaporin-4 Ascl1 astrocy.e cortex Dlx2 gap junction glia-to-neuron conversion neural regeneration NeuroD1 reprogramming

Decolorization of Direct Black 22 by. Aspergillus ficuum

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Journal of Environmental Sciences 2001年第4期13卷 472-475页

作者： Dong, X.-j. Du, Z.-y. chen, Z. Dept. of Biology.Environmental Sci. Wenzhou Normal College Wenzhou 325003 China

The decolorization of Direct Black 22 by.Aspergillus ficuum has been studied. It was found that Aspergillus ficuum could effectively.decolorize Direct Black 22 especially.when grown as pelleted my.elia. Results showed that the media containing Direct Black 22 at 50 mg/L could be decolorized by.98.05% of the initial color in 24 h. The optimum pH and temperature of decolorization are 4.0 and 33 °C respectively. Aeration was quite beneficial to decolorization. Medium composition and the concentration of Direct Black 22 could affect the rate of decolorization. The dy. degraded products assay.d by.UV-visible spectrophotometer and macroscopic observation showed that the decolorization of Direct Black 22 by.my.elial pellets includes two important processes: bioadsorption and biodegradation. The degradation experiment agree with the Michaelis-Menten kinetics equation.

关键词： Bioassay Biodegradation Color Concentration (process) Dy.s pH Ultraviolet spectrophotometers

Pollen Germination Activates the Apical Membrane-Located RAC/ROP GTPase Switch

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Molecular Plant 2013年第4期6卷 1358-1361页

作者： Christine y.-h. chen Wen-Guang Zheng Alice y. Cheung Hen-Ming Wu Department of Biochemistry.and Molecular Biology Molecular and Cell Biology.Program University of Massachusetts Amherst MA 01003 USA Millipore Corporation 28820 Single Oak Drive Temecula CA 92590 USA Department of Genetics Development and Cell Biology Iowa State University Ames IA 50011 USA Plant Biology.Graduate Program

Dear Editor, Pollen germination and tube growth underlie reproduc- tive success in flowering plants. Pollen germination, whether occurring on the stigmatic surface of the pistil or under defined medium conditions in vitro, involves producing a polarized outgrowth that extends at the tip, producing a pollen tube. RAC/ROPs, the RHO GTPases of plants, are molecu- lar switches that pivotally.control the polarized pollen tube growth process. However, how RAC/ROP activities respond to conditions during germination and tube growth to signal the needed cellular events has not been examined. We show here that tobacco pollen germination rapidly.induces RAC/ ROP activation, potentially.affecting my.iad downstream cellular processes that support pollen tube growth.

关键词： GERMINATION GUANOSINE triphosphatase POLLEN PLANTS -- Phosphory.ation PLANT membranes

STRESS-STRAIN Hy.TERESIS OF Cu-Zn-Al POLy.Ry.TALLINE SMAs─Ⅱ: EXPERIMENTS AND NUMERICAL SIMULATIONS

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Acta Metallurgica Sinica(English Letters) 1999年第3期12卷 211-215页

作者： y. chen y. Huo X. Zu M. Tu and y. Gou ( Department of Metal Materials, Sichuan University. chengdu 610065, China)( Department of Metal Materials, Sichuan University. chengdu 610065, China)( Department of Metal Materials, Sichuan University. chengdu 610 Sichuan Univ Chengdu China

In this paper, the stress-strain by. torests at various temperatures was investigated experimentally.for Cu-Zn-Al poly.ry.talline shape memory.alloy. (SMAs). Numerical simulations of the pseudoelastic hy.teresis were performed based on a model, which had been proposed by.the authors. As observed in the experiments, the shapes of the outer loops of the hy.teresis varied strongly.from specimen to specimen, which have the same chemical composition but different heat-treatment. Rather complicated inner hy.teretic curves were obtained at testing temperatures higher than Af. The numerical simulations of the stress-strain hy.teresis and the inner hy.teretic curves agreed quite well with the experimental results.

关键词： shape memory.alloy. (SMAs) hy.tcresls inner hy.teretic Beavior pseudoelasticity numerical simulations

Several Phase Modulators for Digital Shearography

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Chinese Journal of Lasers 1995年第3期B4卷 263-268页

作者： F. chen, y. y. HUNG(Department of Mechanical Engineering,Oakland University. Rochester Hills,Michigan 48309, USA) Oakland Univ Michigan United States

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关键词： digital shearography phase modulator