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A Processive Arabidopsis Formin Modulates Actin Filament Dynamics in Association with Profilin

Molecular Plant 2016年第6期9卷 900-910页

作者： Sha Zhang Chang Liu jiaojiao Wang Zhanhong ren Christopher j. Staiger Haiyun ren Key Laboratory of Cell Proliferation and Regulation Biology of Ministry of Education College of Life Science Beijing Normal University Beijing 100875 People'sRepublic of China Department of Biological Sciences Purdue University Hansen Life Sciences Research Building West Lafayette IN 47907-2064 USA

Formins are conserved regulators of actin cytoskeletal organization and dynamics that have been impli- cated to be important for cell division and cell polarity. The mechanism by which diverse formins regulate actin dynamics in plants is still not well understood. Using in vitro single-molecule imaging technology, we directly observed that the FH1-FH2 domain of an Arabidopsis thaliana formin, AtFH14, processively at- taches to the barbed end of actin filaments as a dimer and slows their elongation rate by 90%. The attach- ment persistence of FH1-FH2 is concentration dependent. Furthermore, by use of the triple-color total internal reflection fluorescence microscopy, we found that ABP29, a barbed-end capping protein, com- petes with FH1-FH2 at the filament barbed end, where its binding is mutually exclusive with AtFH14. In the presence of different plant profilin isoforms, FH1-FH2 enhances filament elongation rates from about 10 to 42 times. Filaments buckle when FH1-FH2 is anchored specifically to cover slides, further indicating that AtFH 14 moves processively on the elongating barbed end. At high concentration, AtFH 14 bundles actin filaments randomly into antiparallel or parallel spindle-like structures; however, the FH1-FH2-mediated bundles become thinner and longer in the presence of plant profilins. This is the direct demonstration of a processive formin from plants. Our results also illuminate the molecular mechanism of AtFH14 in regulating actin dynamics via association with profilin.

关键词： processive formin profilin capping protein actin bundle TIRF microscopy single molecule

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“共享+”模式下平台生态价值共创策略与激励机制

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管理工程学报 2025年第2期39卷 248-261页

作者：任雪杰梁艺馨赵林度南京邮电大学管理学院江苏南京210003 东南大学经济管理学院江苏南京211189

共享平台在构建和完善自身生态品牌时,通过与相关企业或其他平台合作共同创造生态价值,这一模式被称为“共享+”模式。本文首先考虑平台价值独创情形,分析该情形下的最优策略。接着,本文进一步考虑平台作为主创者和多个共创者之间的微... 详细信息

共享平台在构建和完善自身生态品牌时,通过与相关企业或其他平台合作共同创造生态价值,这一模式被称为“共享+”模式。本文首先考虑平台价值独创情形,分析该情形下的最优策略。接着,本文进一步考虑平台作为主创者和多个共创者之间的微分博弈,并在该情形下决策最优努力水平的Nash均衡。最后,本文考虑平台根据共创者努力水平给予激励的Stackelberg主从博弈。本文在分析平台价值独创策略、价值共创策略和共创激励策略时发现,共创激励策略下平台的价值产量和最优收益均最高,且该策略下平台付出的努力最少;其次为无激励的价值共创策略,而价值独创策略表现最差。创造者的最优收益和价值产量在三种策略下均关于时间单调递增,但增速越来越慢,最后趋于收敛值。参数弹性分析表明,共创者的变现能力和价值产出率正向影响均衡解,而边际成本、价值自然损失率、折扣因子均负面影响均衡解。本文结论解释了抖音、拼多多等平台的补贴机制,印证了价值共创是平台和共创者的双赢策略。

关键词：共享平台生态价值共创微分博弈努力水平激励

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Rigid polyurethane foam reinforced with cellulosewhiskers: Synthesis and characterization

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Nano-Micro Letters 2010年第2期2卷 89-94页

作者： Yang Li Hongfeng ren Arthur j.Ragauskas School of Chemistry and Biochemistry Georgia Institute of Technology School of Polymer Textile and Fiber Engineering Georgia Institute of Technology

A novel nanocomposite of rigid polyurethane foam was prepared by the polymerization of a sucrose-based polyol, a glycerol-based polyol and polymeric methylene diphenyl diisocyanate in the presence of cellulose whiskers. The cell morphology of the resulting foams was examined by scanning electron microscopy which showed both the pure foam and the nanocomposite foam had homogeneous cell dispersion and uniform cell size of approximately 200 μm. Analysis of the foams by Fourier transform infrared(FT-IR) spectroscopy indicated that both samples exhibited signals attributed to the polyurethane including the NH stretching and bending vibrations at 3320 cm^(-1) and 1530 cm^(-1), the OC=O vibration at 1730 cm^(-1) and the CO-NH vibration at 1600 cm^(-1). FT-IR analysis of the nanocomposite indicated that cellulose whiskers were crosslinked with the polyurethane matrix as the signal intensity of the OH stretch at 3500 cm^(-1) was significantly reduced in comparison to the spectral data acquired for a control sample prepared from the pure polyurethane foam mixed with cellulose whiskers. According to ASTM standard testing procedures, the tensile modulus, tensile strength and yield strength of the nanocomposite foam were found to be improved by 36.8%, 13.8% and 15.2%, and the compressive modulus and strength were enhanced by 179.9% and 143.4%, respectively. Dynamic mechanical analysis results testified the improvements of mechanical properties and showed a better thermal stability of the nanocomposite foam.

关键词： Nanocomposites Cellulose whiskers Tensile Compressive Thermal

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Flow hydrodynamics in embankment breach

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journal of Hydrodynamics 2015年第6期27卷 835-844页

作者： ZHAO Gensheng VISSER Paul j. ren Yankai UIjTTEWAAL Wim S.j. Department of Hydraulic Engineering Delft University of Technology Flanders Hydraulics Research Flemish Government Department of Mobility and Public Works

Breaching flow occurs during the breach development of the embankment, dike, earthen dam, landslide barrier, etc. and plays an import role in the breaching erosion as the driving force. According to the previous research, the breaching process can be classified into initiation phase, breach widening phase and breach deepening phase. Based on the breaching development classifications, the breaching flow can be seen as a special compound weir flow when the breach channel is in the relatively equilibrium condition. There were five physical flow models were designed in the hypothesis of rectangular shape and trapezoidal shape for the breach channel cross sections to study the breaching flow characteristics. The distributions of water level and velocity were measured and analysed in the breaching flows in overtopping condition and emerged condition. There were two helicoidal flows above the breach channel slopes and triangular hydraulic jump in the downstream of the breach channel in the overtopping condition and emerged condition. The hydraulic energy loss was calculated according to the breaching velocity and water level distribution in the upstream and downstream of the model. It is found that the test results of the breach flow physical model can be valuable to bring insight of the breaching process of embankment and make contributions to the validations and verifications of breach numerical models.

关键词： embankment breach physical model breaching flow helicoidal flow hydraulic jump

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露天边帮开采中充填方式的探讨

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煤矿机械 2025年第1期46卷 99-101页

作者：任晓力中国煤炭科工集团太原研究院有限公司太原030006 山西天地煤机装备有限公司太原030006 煤矿采掘装备国家工程实验室太原030006

针对我国露天边帮开采充填的现状,结合井工开采充填的方式,介绍了矸石充填、膏体充填和高水充填3种边帮充填方式的优缺点,探讨了3种井工开采充填方式应用到露天边帮开采充填的可行性,为露天边帮开采充填设计者提供了一些思路。

关键词：露天边帮开采充填膏体充填高水充填

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Characteristics of EM scattering on dielectric fractal surface

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Chinese Science Bulletin 1997年第6期42卷 523-526页

作者： Wang, MX Li, j ren, L Institute of E.M Field & Microwave Technology Southwest Jiaotong University Chengdu China

The regular and smooth objects are always studied in conventional geometry. But very rough and irregular objects which have self-similarity, the fractal structure, are efficiently solved by fractal geometry. The self-similarity is that the local configuration is similar to the whole configuration. In other words, for each resolution scalar, the form of the curves is similar. Fractal structure exists widely in nature. In this note, band-limited fractal functions

关键词： EM scattering fractal structure rough surface Kirchhoff approximation.

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MARKOV PROCESS ANALYSIS OF ATOM PROBE DATA

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Chinese Physics Letters 1990年第8期7卷 353-356页

作者： WANG Qi T.j.Kinkus ren Dagang Institute of Metal Research Academia SinicaShenyang 110015 Department of Materials of Materials Science and Engineering Northwestern UniversityEvanstonIllinois 60201U.S.A

A geometry model of field evaporation process is set up;with this model the field evaporation process can be described as Markov *** application to the earliest stage of phase transition is *** comparison,Camus’system Fe-Cr 45 at.%is calculated again,and the same result is extracted from our method and intimated in our experimental data.

关键词： process. process field

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New Geiger-Nuttall law of odd-Z nuclei and long-lived island beyond the stable line

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Nuclear Science and Techniques 2013年第5期24卷 92-97页

作者： ren Yuejiao ren Zhongzhou Department of Physics Nanjing University

Recently,we analyze the α-decay data of even-Z nuclei and propose the new Geiger-Nuttall law where the effects of the quantum numbers of α-core relative motion are naturally embedded in the law [Physical Review C 85,044608(2012)].In this paper,we firstly test whether the new law without any change of parameters can be applied to the α-decays of odd-Z nuclei which are more complicated than those of even-even *** the nuclear shell effect around N=126 is analyzed for very proton-rich nuclei with Z=85-92 based on the data of α-decay energies and half-lives.A long-lived island beyond the stable line is proposed where the half-lives of nuclei on this island are abnormally *** mechanism of the appearance of the island and its significance to other mass ranges are discussed.

关键词：长寿命稳定塔衰变数据相对运动质量范围嵌入法量子数

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铁路工程造价“营改增”影响分析

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交通企业管理 2025年第1期40卷 52-54页

作者：田泽仁中国铁建大桥工程局集团有限公司

自2016年4月起,我国开始实施“营改增”税制改革,将原有的增值税和营业税合并为一种税种。这一改革旨在促进国民经济发展,优化税制结构,减轻企业负担,提高税收透明度等。然而,“营改增”对于铁路工程建设所产生的影响却备受关注。铁路... 详细信息

自2016年4月起,我国开始实施“营改增”税制改革,将原有的增值税和营业税合并为一种税种。这一改革旨在促进国民经济发展,优化税制结构,减轻企业负担,提高税收透明度等。然而,“营改增”对于铁路工程建设所产生的影响却备受关注。铁路工程建设是我国基础设施建设的重要领域之一,对国民经济的发展起着至关重要的作用。由于铁路工程建设所需资金巨大、工程周期长、风险高等特点.

关键词：铁路工程 “营改增” 工程造价税收政策会记核算企业创新

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Dynamic crossover in [VIO^(2+)][Tf_(2)N-]_(2) ionic liquid

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Chinese Physics B 2021年第1期30卷 374-379页

作者： Gan ren Departments of Physics&Key Laboratory of Photonic and Optical Detection in Civil Aviation Civil Aviation Flight University of ChinaGuanghan 618307China

Ionic liquids usually behave as fragile liquids,and the temperature dependence of their dynamic properties obeys supper-Arrhenius *** this work,a dynamic crossover is observed in([VIO^(2+)][Tf_(2)N-]_(2)) ionic liquid at the temperature of 240-800 *** diffusion coefficient does not obey a single Arrhenius law or a Vogel-Fulcher-Tammann(VFT) relation,but can be well fitted by three Arrhenius laws or a combination of a VFT relation and an Arrhenius *** origin of the dynamic crossover is analyzed from correlation,structure,and *** gets a stronger backward correlation at a lower temperature,as shown by the fractal dimension of the random *** temperature dependence function of fractal dimension,heterogeneity order parameter,and thermodynamic data can be separated into three regions similar to that observed in the diffusion *** two crossover temperatures observed in the three types of data are almost the same as that in diffusion coefficient fitted by three Arrhenius *** results indicate that the dynamic crossover of[VIO2+][Tf2 N-]2 is attributed to the heterogeneous structure when it undergoes cooling.

关键词： ionic liquids dynamic crossover heterogeneity order parameter fractal dimension fragile

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