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Is ABP1 an Auxin Receptor Yet？

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Molecular Plant 2011年第4期4卷 635-640页

作者： Jing-Hua shi zhen-Biao Yang Center for Plant Cell Biology Department of Botany and Plant Sciences University of California Riverside CA 92521 USA

AUXIN BINDING PROTEIN 1 （ABP1） has long been proposed as an auxin receptor to regulate cell expansion. The embryo lethality of ABP1-null mutants demonstrates its fundamental role in plant development, but also hinders investigation of its involvement in post-embryonic processes and its mode of action. By taking advantage of weak alleles and inducible systems, several recent studies have revealed a role for ABP1 in organ development, cell polarization, and shape formation. In addition to its role in the regulation of auxin-induced gene expression, ABP1 has now been shown to modulate non-transcriptional auxin responses. ABP1 is required for activating two antagonizing ROP GTPase signaling pathways involved in cytoskeletal reorganization and cell shape formation, and participates in the regulation of clathrinmediated endocytosis to subsequently affect PIN protein distribution. These exciting discoveries provide indisputable evidence for the auxin-induced signaling pathways that are downstream of ABP1 function, and suggest intriguing mechanisms for ABPl-mediated polar cell expansion and spatial coordination in response to auxin.

关键词： Hormonal regulation hormone biology receptors signal transduction cell signaling.

Microstructures and grain refinement performance of Al-Ti-B-C grain refiner via powder metallurgy

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Rare Metals 2022年第7期41卷 2357-2362页

作者： Cong Xu Wen-Long Xiao shi-zhen Wen Yue-Jun zhen Chao-Li Ma Key Laboratory of Aerospace Advanced Materials and Performance of Ministry of Education School of Material Science and EngineeringBeihang UniversityBeijing 100191China Lizhong Group Baoding Lizhong Wheel Manufacturing Co.Ltd.Baoding 071000China

The Al-5Ti-0.5B-0.5C grain refiner was pre-pared by powder metallurgy(PM).Microstructures of the grain refiner and its grain refinement performance in commercially pure aluminum(Al)were investigated by X-ray diffraction(XRD),scanning electron microscopy(SEM),and differential scanning calorimetry(DSC).It is found that the average grain size of commercially pure Al can be reduced from~15,000 to~180μm by the addition of Al-5Ti-0.5B-0.5C grain refiner prepared by PM,based on 0.01 wt%Ti *** grain refinement efficiency begins to decrease slightly when the grain refiner is kept in the melt for 60 *** grain refinement is attributed to high stability,proper size,and high density of Al3Ti,TiB2,and TiC particles.

关键词： Al–Ti–B–C Powder metallurgy Microstructure Grain refinement

Effect of Hf on Stress Rupture Properties of DD6 Single Crystal Superalloy After Long Term Aging

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Journal of Iron and Steel Research International 2012年第7期19卷 66-70页

作者： shi zhen-xue LI Jia-rong LIU shi-zhong National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095China

The specimens of the second generation single crystal superalloy DD6 with different Hf contents were prepared in the directionally solidified furnace with a high temperature gradient. The long term aging of the specimens after full heat treatment was performed at 1040℃for 800 h. The effect of Hf on the microstructure and stress rupture properties under 980℃/250 MPa of the alloy after long term aging was investigated. The results show that the γ＇ coarsening and rafting and no topologically close packed phase （TCP） are observed in the microstructures of DD6 alloy with different Hf contents after aged at 1 040℃ for 800 h. It indicates that DD6 alloy with different Hf contents all possesses good microstructure stability. With increasing Hf content the rupture life after long term aging turns shorter and the elongation represents the increasing first and decreasing afterwards. The fracture mechanism of the alloy with different Hf contents at 980℃/250 MPa all shows dimple model. The influence of the microstructures on the stress rupture properties of the alloy is also discussed.

关键词： DD6 single crystal superalloy stress rupture property long term aging

Construction and Verification of a Simple Smooth Chaotic System

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Communications in Theoretical Physics 2007年第2X期48卷 267-274页

作者： ZHANG Xiao-Dan shi Feng WANG zhen School of Applied Science University of Science and Technology Beijing Beijing 100083 China

This article introduces a new chaotic system of three-dimensional quadratic autonomous ordinary differential equations, which can display different attractors with two unstable equilibrium points and four unstable equilibrium points respectively. Dynamical properties of this system are then studied. Furthermore, by applying the undetermined coefficient method, heteroclinic orbit of shil＇nikov＇s type in this system is found and the convergence of the series expansions of this heteroclinic orbit are proved in this article. The shil＇nikov＇s theorem guarantees that this system has Smale horseshoes and the horseshoe chaos.

关键词： chaotic attractors three-dimensional quadratic autonomous dynamical system equilibrium point

Gas sensitivity of indium oxide

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中国有色金属学会会刊：英文版 2009年第B9期19卷 80-82页

作者： HUANG shi-zhen LIN Wei CHEN Wen-zhe Fujian Key Laboratory of Microelectronic IC Fuzhou University Fuzhou 350002 China College of Material Science and Engineering Fuzhou University Fuzhou 350002 China

The yellow indium oxide nanoparticles were prepared by sintering the white deposition at 500 ℃. The crystalline indium chloride and ammonia were used as the starting material. The results show that, by analyzing the particles through X-ray diffraction and TEM, the particles are very small, spherical, and the particle size is about 40 nm. The direct-heat components made from indium oxide in Cl2 and NO2 was tested respectively, the component is far more sensitive to NO2 than to Cl2 at low heating temperature, and the status is reversed at high heating temperature..

关键词：氧化铟透射电子显微镜粒子烧结法气敏颗粒大小二氧化氮加热温度白色沉淀

Effects of Dendritic Orientation on Stress Rupture Properties of DD6 Single Crystal Superalloy

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Journal of Iron and Steel Research International 2011年第10期18卷 66-71页

作者： shi zhen-xue LI Jia-rong LIU shi-zhong ZHAOJin-qian National Key Laboratory of Science and Technology on Advanced High Temperature Structural Materials Beijing Institute of Aeronautical Materials Beijing 100095 China

DD6 single crystal superalloy slabs were prepared with seed method in the direetionally solidified furnace with high temperature gradient. The transverse stress rupture properties and fracture hehaviour of the alloy at 760 ℃/758 MPa, 850 ℃/550 MPa and 980 ℃/250 MPa were investigated and compared with those of longitudinal specimens. The transverse stress rupture lives are corresponding with the longitudinal stress rupture lives at 760 ℃/758 MPa and 850 ℃/550 MPa. The transverse stress rupture lives are slightly less than the longitudinal stress rupture lives at 980 ℃/ 250 MPa. The fracture mechanism of the transverse stress rupture of the alloy at 760 ℃/758 MPa shows quasi-cleav- age mode and the fracture mechanism at 980 ℃/250 MPa shows dimple mode, while the fracture mechanism at 850 ℃/ 550 MPa shows quasi-cleavage and dimple mixture mode. At higher temperature and lower stress, the microeracks are easier to initiate and interconnect in the transverse specimen than those in longitudinal specimen because there are interdendritic regions perpendicular to the axis of stress.

关键词： DD6 single crystal superalloy stress rupture property fracture behaviour

The Synthesis of Dialdehyde from Sodium Hydrogen Telluride with 1,1',3,3'-Tetramethyl-2,2'-bis-benzimidazolium Salt

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Chinese Chemical Letters 2002年第9期13卷 836-838页

作者： Yue, Ke Fen Gu, Huan shi, zhen Department of Chemistry Northwest University Xi'an 710069 China

The reaction of bis-benzimidazolium salts with sodium hydrogen telluride is reported, and a new synthetic method for dialdehydes is provided.

关键词： Bis-benzimidazolium salt sodium hydrogen telluride dialdehyde synthesis.

Synthesis and application of rhodamine-based fluorescent probe dyes with spacer linker arm

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Chinese Chemical Letters 2007年第6期18卷 667-669页

作者： Yong Gao Jian Li Li zhen shi College of Chemistry and Materials Science Fujian Normal University Fuzhou 350007 China Department of Chemistry Northwest University Xi’an 710069 China

When rhodamine-based fluorescent probe dyes are used to track target molecules they always perturb the behavior of target molecules because of steric hindrance effect. In order to minimize potential steric problems, a kind of rhodamine-based fluorescent probe dye with spacer linker arm was designed and synthesized and its application in immunofluorescence histochemistry was investigated.

关键词： Rhodamine Fluorescent probe dye Spacer linker arm Synthesis Immunofluorescence histochemistry

Study on the Reaction of Benzimidazolium Salt with Amine Compounds

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Chinese Chemical Letters 2003年第6期14卷 561-564页

作者： Yun Xia WANG Lin JIA zhen shi Department of Chemistry Northwest UniversityXian 710069

The addition-hydrolysis reaction of benzimidazolium salt with some mono- and bifunctional amine nucleophiles is reported, and a novel method of biomimetic synthesis for formamides and heterocycle compounds is provided.

关键词： Tetrahydrofolate coenzyme model benzoimidazole methiodide salt amine compound biomimetic synthesis.