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Effects of hydrogen on a tungsten grain boundary:A first-principles computational tensile test

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Progress in Natural Science:Materials International 2011年第3期21卷 240-245页

作者： Hong-bo zhou,shuo JIN,Ying ZHANG,Guang-hong LU Department of Physics,Key Laboratory of Micro-nano Measurement-Manipulation and Physics(Ministry of Education),Beijing University of Aeronautics and Astronautics,Beijing 100191,China Department of Physics Key Laboratory of Micro-nano Measurement-Manipulation and Physics (Ministry of Education) Beijing University of Aeronautics and Astronautics Beijing 100191 China

A first-principles computational tensile test has been preformed to investigate the effects of hydrogen on a tungsten grain *** has been found that the maximum ideal tensile strength of the tungsten grain boundary with hydrogen atom segregation was 32.85 GPa,which was about 9%lower than that of the clean tungsten grain boundary(36.23 GPa).This indicated that the theoretical strength of the tungsten grain boundary became weaker in the presence of the hydrogen *** configuration analysis showed that the grain boundary fracture was caused by the interfacial bond *** Griffith fracture energy was calculated to be 161 meV/A~2(2.58 J/m~2) and 155 meV/A~2(2.48 J/m~2) for the tungsten grain boundary without and with the hydrogen atom segregation,*** solution energy of the hydrogen atom in a fracture free surface was -0.31 eV,which was 0.08 eV lower than that of the hydrogen atom in a tungsten grain *** indicated that hydrogen was a grain boundary embrittler according to the Rice-Wang thermodynamic *** Bader charge analysis suggested that the physical origin for hydrogen-induced embrittlement was the charge transfer induced by hydrogen in the tungsten grain boundary.

关键词： tungsten hydrogen grain boundary tensile strength first-principles

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先秦“诗言志”观念的孕育与完型

中国文学研究 2010年第2期 35-38页

作者：周朔广东教育学院中文系广东广州510303

《尚书.尧典》"诗言志",其内容应当与祭祀天地鬼神、祖宗社稷的活动有关,这是"诗言志"观念的最早孕育。《左传》"诗以言志",当指春秋时期所盛行的"赋诗言志"或"称诗言志",这是"诗言志"观念在诗歌接受领域的发展。荀子提出的"诗言是其志... 详细信息

《尚书.尧典》"诗言志",其内容应当与祭祀天地鬼神、祖宗社稷的活动有关,这是"诗言志"观念的最早孕育。《左传》"诗以言志",当指春秋时期所盛行的"赋诗言志"或"称诗言志",这是"诗言志"观念在诗歌接受领域的发展。荀子提出的"诗言是其志也",不仅规范了诗"言志"的内容,而且确认了诗是"言志"的文体,这是"诗言志"观念在先秦时期的初步完型。

关键词：诗言志诗以言志孕育完型

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一类反中心对称矩阵反问题的最小二乘解

系统科学与数学 2007年第6期27卷 858-865页

作者：周硕吴柏生东北电力大学理学院吉林132012 吉林大学数学研究所长春130012

给定矩阵Y,X和B,得到了矩阵方程YAX=B的反中心对称最小二乘解.利用矩阵的标准相关分解给出解存在的充要条件及其解的一般表达式.

关键词：反中心对称矩阵最小二乘解反问题标准相关分解(CCD)

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儿童早期词切分能力的发展

学前教育研究 2015年第3期 3-9页

作者：赵微周硕陕西师范大学教育学院西安710062 西安美术学院艺术教育学院西安710000

以幼儿园小、中、大班共140名儿童为被试，采用实验法探讨3-6岁学前儿童早期词切分的发展状况及特点，结果表明儿童在学前阶段词切分能力已经开始发展。儿童词切分能力的发展经历了从句子到字再到词或者词块的过程。儿童词切分能力的发... 详细信息

以幼儿园小、中、大班共140名儿童为被试，采用实验法探讨3-6岁学前儿童早期词切分的发展状况及特点，结果表明儿童在学前阶段词切分能力已经开始发展。儿童词切分能力的发展经历了从句子到字再到词或者词块的过程。儿童词切分能力的发展在口语与书面语中经历了从分离到趋于一致的过程，同时词汇类型对儿童词切分任务的完成有一定影响。

关键词：词切分词意识儿童语言发展

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反中心对称矩阵的广义特征值反问题

高等学校计算数学学报 2005年第1期27卷 53-59页

作者：周硕吴柏生吉林大学数学研究所吉林 132012 吉林大学数学研究所长春 130012 东北电力学院数理科学系

1 引言由结构动力学等实际问题中提出的矩阵广义特征值反问题在固体力学、分子光谱学、结构设计、振动控制、系统参数识别等领域都有重要应用,目前关于广义特征值反问题已有不少研究成果(见[1-8]).而中心对称矩阵与反中心对称矩阵在... 详细信息

1 引言由结构动力学等实际问题中提出的矩阵广义特征值反问题在固体力学、分子光谱学、结构设计、振动控制、系统参数识别等领域都有重要应用,目前关于广义特征值反问题已有不少研究成果(见[1-8]).而中心对称矩阵与反中心对称矩阵在信息论、线性系统理论、线性估计理论及数值分析等领域中应用广泛(见[9-11]).本文将广义特征值反问题关于中心对称矩阵的研究结果(见[6,11]),推广到反中心对称矩阵的情况. 令Rn×m表示所有n×m阶实矩阵集合;ORn×n表示所有n阶正交阵的集合;用

关键词： anti-centrosymmetric matrices generalized eigenvalue inverse problem optimal approximation.

中心主子矩阵约束下矩阵反问题X^TAX=B的双对称解及其最佳逼近

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系统科学与数学 2014年第8期34卷 985-991页

作者：周硕王霖东北电力大学理学院吉林132012

文章研究了中心主子矩阵约束下矩阵方程X^TAX=B的双对称解.利用子空间的基将约束问题转化为非约束问题的方法,得到了有解的充分必要条件及解的一般表达式.进而,考虑了与之相关的任意给定矩阵的最佳逼近问题.

关键词：矩阵反问题中心主子矩阵约束双对称矩阵最佳逼近

Viscosity and structure relationship with equimolar substitution of CaO with MgO in the CaO–MgO–Al_(2)O_(3)–SiO_(2)slag melts

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 70-79页

作者： Yong Hou shuo Zhang Jie Dang Jia Guo Hanghang zhou Xuewei Lü College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this *** most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina *** results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO *** transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO *** of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents *** analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO ***,bond strength is another important factor affecting the slag *** occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.

关键词： aluminosilicate viscosity structure spectroscopy

Non-coding RNAs in acute ischemic stroke:from brain to periphery

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Neural Regeneration Research 2025年第1期20卷 116-129页

作者： shuo Li Zhaohan Xu Shiyao Zhang Huiling Sun Xiaodan Qin Lin Zhu Teng Jiang Junshan zhou Fuling Yan Qiwen Deng Department of Neurology Nanjing First HospitalNanjing Medical UniversityNanjingJiangsu ProvinceChina Department of Neurology Zhongda HospitalSchool of MedicineSoutheast UniversityNanjingJiangsu ProvinceChina General Clinical Research Center Nanjing First HospitalNanjing Medical UniversityNanjingJiangsu ProvinceChina

Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and *** predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain *** innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental *** expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic ***,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and *** particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic *** this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and *** from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.

关键词： acute ischemic stroke apoptosis blood–brain barrier damage circular RNAs excitatory toxicity long non-coding RNAs microRNAs neuroinflammation non-coding RNAs oxidative stress

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双中心矩阵反问题及其在电网络理论中的应用

工程数学学报 2007年第4期24卷 611-617页

作者：周硕吴柏生东北电力大学理学院吉林132012 吉林大学数学研究所长春130012

本文研究双中心矩阵反问题。建立了双中心矩阵反问题的最小二乘解,得到了解的具体表达式。讨论了用双中心矩阵反问题的解构造给定矩阵的最佳逼近问题,给出该问题有解的充分必要条件和解的表达式。设计了相应的算法并给出了其在电网络理... 详细信息

本文研究双中心矩阵反问题。建立了双中心矩阵反问题的最小二乘解,得到了解的具体表达式。讨论了用双中心矩阵反问题的解构造给定矩阵的最佳逼近问题,给出该问题有解的充分必要条件和解的表达式。设计了相应的算法并给出了其在电网络理论中的应用。

关键词：双中心矩阵反问题最佳逼近电网络理论