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Tribological properties of PTFE-based fabric composites at cryogenic temperature

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Friction 2024年第2期12卷 245-257页

作者： Mingkun XU Zidan wang Lihe GUO Liming TAO Tianbao MA Tingmei wang Qihua wang Key Laboratory of Science and Technology on Wear and Protection of Materials Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Fabric composites are widely employed in self-lubricating bearing liners as solid lubrication materials.Although the tribological behaviors of fabric composites have been extensively studied,the cryogenic tribological properties and mechanisms have been scarcely reported and are largely unclear to instruct material design for aerospace and other high-tech applications.Herein,the tribological properties of polytetrafluoroethylene(PTFE)-based hybrid-fabric composites were investigated at cryogenic and ambient temperatures in the form of pin-on-disk friction under heavy loads.The results suggest that the friction coefficients of the hybrid-fabric composites obviously increase with a decrease in wear when the temperature drops from 25 to−150°C.Moreover,thermoplastic polyetherimide(PEI),as an adhesive for fabric composites,has better cryogenic lubrication performance than thermosetting phenol formaldehyde(PF)resin,which can be attributed to the flexible chemical structure of PEI.The excellent lubrication performance of hybrid-fabric composites is attributed to the transfer film formed by PTFE fibers on the surface of fabrics.

关键词： cryogenic temperatures fabric composites friction and wear transfer film

Gibberellin promotes cambium reestablishment during secondary vascular tissue regeneration after girdling in an auxin-dependent manner in Populus

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Journal of Integrative Plant Biology 2024年第1期66卷 86-102页

作者： Yufei Zhang Lingyan wang Yuexin Wu Donghui wang Xin‐Qiang He State Key Laboratory of Protein and Plant Gene Research School of Life SciencesPeking UniversityBeijing 100871China

Secondary vascular tissue(SVT)development and regeneration are regulated by phytohormones.In this study,we used an in vitro SVT regeneration system to demonstrate that gibberellin(GA)treatment significantly promotes auxin-induced cambium reestablishment.Altering GA content by overexpressing or knocking down ent-kaurene synthase(KS)affected secondary growth and SVT regeneration in poplar.The poplar DELLA gene GIBBERELLIC ACID INSENSITIVE(PtoGAI)is expressed in a specific pattern during secondary growth and cambium regeneration after girdling.Overexpression of PtoGAI disrupted poplar growth and inhibited cambium regeneration,and the inhibition of cambium regeneration could be partially restored by GA application.Further analysis of the PtaDR5:GUS transgenic plants,the localization of pin-FORMED 1(pin1)and the expression of auxin-related genes found that an additional GA treatment could enhance the auxin response as well as the expression of pin1,which mediates auxin transport during SVT regeneration.Taken together,these findings suggest that GA promotes cambium regeneration by stimulating auxin signal transduction.

关键词： auxin cambium gibberellin Populus secondary vascular tissue regeneration

Exogenous nerve growth factor protects the hypoglossal nerve against crush injury

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Neural Regeneration Research 2015年第12期10卷 1982-1988页

作者： Li-yuan Fan Zhong-chao wang pin wang Yu-yan Lan Ling Tu Department of Prosthodontics Stomatological Hospital of Sichuan Medical University Orofacial Reconstruction and Regeneration Laboratory Sichuan Medical University Department of Endodontics Stomatological Hospital of Sichuan Medical University Department of Anatomy and Physiology College of StomatologyCentral South University

Studies have shown that sensory nerve damage can activate the p38 mitogen-activated protein kinase（MAPK）pathway,but whether the same type of nerve injury after exercise activates the p38MAPK pathway remains unclear.Several studies have demonstrated that nerve growth factor may play a role in the repair process after peripheral nerve injury,but there has been little research focusing on the hypoglossal nerve injury and repair.In this study,we designed and established rat models of hypoglossal nerve crush injury and gave intraperitoneal injections of exogenous nerve growth factor to rats for 14 days.p38MAPK activity in the damaged neurons was increased following hypoglossal nerve crush injury;exogenous nerve growth factor inhibited this increase in acitivity and increased the survival rate of motor neurons within the hypoglossal nucleus.Under transmission electron microscopy,we found that the injection of nerve growth factor contributed to the restoration of the morphology of hypoglossal nerve after crush injury.Our experimental findings indicate that exogenous nerve growth factor can protect damaged neurons and promote hypoglossal nerve regeneration following hypoglossal nerve crush injury.

关键词： nerve regeneration p38MAPK mitogen-activated protein kinase nerve growth factor hypoglossal nerve crush injury nerve injury neural regeneration

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断控缝洞型油藏注采井间油水界面预测方法

深圳大学学报（理工版） 2024年第2期41卷 152-162页

作者：王远征曹仁义贾品中国石油大学(北京)油气资源与探测国家重点实验室北京102249 中国石油大学(北京)石油工程学院北京102249

断控缝洞型碳酸盐岩油藏受大型克拉通内走滑断裂控制和改造,其纵向多发育为断裂复合储层体(裂缝-溶洞体),该储集体既是油气运移通道,又是储层空间,其空间及配置关系复杂.为实现注水开发过程中油水界面和见水规律的准确分类及预测,并提... 详细信息

断控缝洞型碳酸盐岩油藏受大型克拉通内走滑断裂控制和改造,其纵向多发育为断裂复合储层体(裂缝-溶洞体),该储集体既是油气运移通道,又是储层空间,其空间及配置关系复杂.为实现注水开发过程中油水界面和见水规律的准确分类及预测,并提供后续开发方案和对策指导,以单一溶洞下的油水界面运移特征为基础,利用物质平衡方程建立一种新的断控缝洞型油藏多溶洞连通下的油水运移数学模型,基于稳态逐步替换法形成了注采井间动态油水界面实时追踪预测方法.与常规数值模拟方法相比,该模型构建简易,计算效率高,综合考虑了油水密度差异和井-裂缝-溶洞间的复杂纵向配置关系,能够较为准确预测生产井的见水规律、各溶洞油水界面运移位置及剩余油分布等各项开发指标.研究结果表明,多缝洞开发单元受生产制度和缝-洞储层参数影响,油井生产期将出现3个阶段(纯油、油水同产和纯水期);合理的采油速度与注水量可有效保持地层压力,兼顾采出程度和裂缝应力敏感效应;裂缝传导率越高,储层能量恢复越快,油水界面上升也变快;随着注采井间溶洞体积及裂缝传导率差异增大,油水同产期将变长.最后,对比Eclipse数值模拟器与本研究模型计算结果,分析溶洞体物性参数(渗透率和孔隙度)对油水界面运移速度的影响.鉴于目前断控缝洞型油藏地质构造及裂缝-溶洞体配置关系的多样性,开展多井生产动态与模型预测结果的实时拟合工作是目前油水界面评价与追踪的有效方法.本研究模型为断控缝洞型油藏见水预警、注采参数优化及剩余油挖潜对策制定提供了基础理论与方法.

关键词：油田开发断控缝洞型油藏碳酸盐岩见水预警注采参数优化生产动态缝洞配置关系

众包情报的四象限模型在科技安全风险预警中的应用

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情报杂志 2024年第5期43卷 116-122页

作者：王君李品李璟致江苏警官学院南京210031 扬州大学扬州225009 南京工业大学南京211816

[研究目的]自维基百科产生以来,美国情报界开始重视众包情报,并运用众包情报开展情报搜集和技术创新。分析美国近年来众包情报运用案例,为众包情报运用于我国科技安全风险预警提供新视角和新启发。[研究方法]该文运用众包四象限理论构... 详细信息

[研究目的]自维基百科产生以来,美国情报界开始重视众包情报,并运用众包情报开展情报搜集和技术创新。分析美国近年来众包情报运用案例,为众包情报运用于我国科技安全风险预警提供新视角和新启发。[研究方法]该文运用众包四象限理论构建科技安全风险预警模型,剖析典型众包情报案例,归纳总结其在情报搜集、技术创新和助推共同体文化方面的价值和挑战,分析科技安全风险预警中的众包情报需求。[研究结论]基于我国科技情报预警情境,构建众包情报任务场景,并从维护科技安全的情报保障、国产软硬件使用的数据支持、前沿科技治理的情报感知以及科技文化认同的情报赋能等四方面提出众包情报在科技安全风险预警中的应用路径。

关键词：科技情报情报搜集众包情报科技安全风险预警

A bacterial protein Rhp-PSP inhibits plant viral proliferation through endoribonuclease activity

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Journal of Integrative Agriculture 2024年第6期23卷 1967-1978页

作者： Lijie Chen Qianze Peng Xiaohua Du Weixing Zhang Ju’e Cheng Shu’e Sun Deyong Zhang pin Su Yong Liu Longping Branch College of BiologyHunan UniversityChangsha 410082China State Key Laboratory of Hybrid Rice/Institute of Plant Protection Hunan Academy of Agricultural SciencesChangsha 410125China

Plant virus causes massive crop losses globally.However,there is currently no effective measure to control plant viral disease.Previously,we identify an antiviral protein Rhp-PSP,produced by the bacterial Rhodopseudomonas palustris strain JSC-3b.In this study,we discover that the antiviral activity of Rhp-PSP relies on its endoribonuclease activity.Converting the arginine(R)residue at position 129 onto alanine(A)abolishs its endoribonuclease activity on coat protein(CP)RNA of tobacco mosaic virus(TMV),consequentially,compromises the antiviral activity of Rhp-PSP.Further investigation demonstrates that,the mutant Rhp-PSP^(R129A)is unable to form the homotrimer as the wild type,indicating the importance of quaternary junction for the endoribonuclease activity.Overexpression of Rhp-PSP in Nicotiana benthamiana significantly enhances the resistance against TMV of seedlings,while expression of Rhp-PSP^(R129A)did not,confirming that endoribonuclease activity is responsible for the antiviral activity of Rhp-PSP.In addition,foliar spray of Rhp-PSP solution on tomato and pepper plants significantly reduces the disease index of viral diseases,indicating that Rhp-PSP shows potential to develop antiviral agent in practice.

关键词： Rhodopseudomonas palustris Rhp-PSP tobacco mosaic virus endoribonuclease antiviral activity

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中华文明连续不断的历史逻辑与中国路径

学术研究 2024年第3期 1-7页

作者：李凭华南师范大学历史文化学院广东广州510631

中华文明是世界上独一无二的经5000年毫不断裂而长存至今的历史现象,以二十四史为脊梁的历史文献和层出不穷的考古遗存是不容置疑的铁证。中华文明毫不断裂的重要原因在于中华民族的勤劳勇敢,依靠勤劳而开天辟地,不畏强暴而驱逐豺狼,才... 详细信息

中华文明是世界上独一无二的经5000年毫不断裂而长存至今的历史现象,以二十四史为脊梁的历史文献和层出不穷的考古遗存是不容置疑的铁证。中华文明毫不断裂的重要原因在于中华民族的勤劳勇敢,依靠勤劳而开天辟地,不畏强暴而驱逐豺狼,才使得中华民族日益繁荣昌盛。中华民族具有的勤劳勇敢基因源自遥远的石器时代,是经历近百万年艰苦磨炼形成的,因此能够驱动中华文明持续发展。中华文明持续发展的现代意义在于,不但为世界文明树立了和平与文治的榜样,而且增强了中华民族自立于世界前列的信心。因此,应该努力贯彻“让中华优秀传统文化成为现代的”方针,尽力守护和发扬中华文明的传统。

关键词：中华民族中华文明历史文献考古资料

影戏之暗影:重绘中国早期的电影接受(1897—1920)

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当代电影 2024年第4期 71-77页

作者：李频浙大宁波理工学院传媒与法学院

迄今为止有关中国早期电影接受的叙述,往往将其描述为电影这个充满现代性魅力的新媒介如何吸引和征服观众的过程,却忽视了这个过程中可能遭遇的挫折和失败。然而,早期观众有关电影的负面评价和想象同样深刻地影响了当时电影文化的生成... 详细信息

迄今为止有关中国早期电影接受的叙述,往往将其描述为电影这个充满现代性魅力的新媒介如何吸引和征服观众的过程,却忽视了这个过程中可能遭遇的挫折和失败。然而,早期观众有关电影的负面评价和想象同样深刻地影响了当时电影文化的生成和变化,甚至展示出一种另类的电影经验。因此,有关中国早期电影负面想象的历史研究,为重绘当时的电影接受提供了新的可能。

关键词：早期电影接受电影恐惧电影的负面想象

高职院校工匠精神教育课程教学体系的构建:要素、原则与路径

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中国职业技术教育 2024年第17期 71-77页

作者：邓德艾王频湖南安全技术职业学院湖南现代物流职业技术学院

高职院校工匠精神教育课程教学体系由“三嵌套式”目标体系、“金字塔型”内容体系和“全场景化”过程体系组成,需要遵循价值性和知识性相统一、传承性和创新性相融合、整体性和层次性相结合的构建原则,通过培养好“大先生”,建设好“... 详细信息

高职院校工匠精神教育课程教学体系由“三嵌套式”目标体系、“金字塔型”内容体系和“全场景化”过程体系组成,需要遵循价值性和知识性相统一、传承性和创新性相融合、整体性和层次性相结合的构建原则,通过培养好“大先生”,建设好“大教材”,组织好“大教学”的多元路径推动高职院校工匠精神教育的有效施行。

关键词：高职院校工匠精神教育课程教学体系