creep by nanoindentation
【课程大纲】《木材科学与工程专业外语》
《木材科学与工程专业外语》课程大纲一、课程概述课程名称（中文）：专业外语（英文）：Professional English for Wood Science and Engineering 课程编号：14351073课程学分：3.0课程总学时：48课程性质：（专业课）二、课程内容简介（300字以内）木材科学与工程专业英语是在学习大学英语和相关专业课后而开设的一门专业核心课。
本课程内容主要包括木材结构、木材物理化学性能、木材力学性能、木材保护、木材干燥、胶粘剂、木质人造板等。
三、教学目标与要求《木材科学与工程专业英语》课程既为学生继续英语学习并同时接受专业训练提供帮助。
通过本课程的学习，要求学生既要掌握专业英语初步的“读写听”能力，同时巩固学过的专业知识，学习一些新的木材科学与工程知识。
本课程教学采用多媒体辅助教学，引导学生将英语学习和专业学习有机地结合起来，锻炼学生理解英文文献、正确翻译文献以及初步专业英语写作的能力。
四、教学内容与学时安排绪论Introduction（2学时）1. 教学目的与要求：了解木材资源、木材分类、木材特性等方面的英语知识;掌握本部分出现的英语单词。
2. 教学重点与难点：重点：掌握木材特性的英文专业术语；难点：一般性木材科技英文习惯表达法。
第一章Structure and Function of Wood/ 木材结构与功能（7学时）1. 教学目的与要求：了解不同尺度下的木材宏观构造特征的英语知识；掌握本部分出现的英语单词。
2. 教学重点与难点：重点：木材宏观构造特征的英文基本专业术语；难点：理解并掌握木材宏观构造特征的基本概念的英文描述。
第一节Biological Structure of Wood at Decreasing Scales /木材宏观构造（3学时）一、The tree/ 树木（0.2学时）二、Softwood and Hardwood/ 针叶树材和阔叶树材（0.2学时）三、Sapwood and Heartwood/边材和心材（0.3学时）四、Axial and Radial Systems/轴向和径向体系（0.3学时）五、Planes of Section/三切面（0.4学时）六、Vascular Cambium/维管形成层（0.2学时）七、Growth Rings/年轮、生长轮（0.4学时）八、Cells in Wood/木材细胞（0.4学时）九、Cell walls/细胞壁（0.4学时）十、Pits/纹孔（0.2学时）第二节Microscopic Structure of Softwoods and Hardwoods/针叶树材和阔叶树材微观构造（2学时）一、Softwoods/ 针叶树材（1学时）（一）Tracheids/管胞（0.3学时）（二）Axial Parenchyma and Resin Canal Complexes/轴向薄壁组织和树脂道（0.4学时）（三）Rays/木射线（0.3学时）二、Hardwoods/ 阔叶树材（1学时）（一）Vessels/导管（0.3学时）（二）Fibers /木纤维（0.2学时）（三）Axial Parenchyma/轴向薄壁组织（0.2学时）（四）Rays/木射线（0.2学时）第三节Juvenile Wood and Reaction Wood/幼龄材和应力木（1学时）一、Juvenile Wood/ 幼龄材（0.5学时）二、Reaction Wood/ 应力木（0.5学时）第四节The Properties of Wood Valuable in Identification /对木材识别有价值的木材物理性质（1学时）一、Color / 材色（0.2学时）二、Luster / 光泽（0.2学时）三、Grain and Texture/纹理和结构（0.4学时）四、Odor and taste / 木材的气味和滋味（0.2学时）第二章Chemical components of wood / 木材化学组成（2学时）1. 教学目的与要求：掌握木材化学成分的组成、定义。
Sn-Ag-Cu无铅球栅阵列焊点塑性表征
Sn-Ag-Cu无铅球栅阵列焊点塑性表征杨淼森;孙凤莲;孔祥霞;周云芳【摘要】The nanoindentation was performed on the plasticity of Sn-Ag-Cu(SAC) lead-free ball grid array(BGA) solder joint. The ratio of plastic strain to total strain was used to characterize the solder plasticity.SAC305/Cu, SAC0307 /Cu and SAC0705BiNi/Cu component solder joints were compared in terms of dynamic hardness, creep resistance and plasticity. The dynamic hardness of three kinds of solder decreases with increasing the penetration depth. For SAC0705BiNi/Cu, the ultimate dynamic hardness is the highest, and the indentation depth is the smallest. Then, the strain hardening phenomenon of SAC305/Cu is more obvious than that of the others. Thus, the order of creep resistance from big to small is SAC0705BiNi/Cu, SAC305/Cu and SAC0307/Cu. The plasticities of SAC0705BiNi/Cu and SAC305/Cu solder joints are similar. Compared with the other two types of solder, through adding Bi and Ni elements, the hardness and solder creep resistance of SAC0705BiNi solder are improved, and the good plasticity is still maintained.%通过纳米压痕的方法，采用塑性应变与总应变的比值表征塑性，对 SAC305/Cu、SAC0307/Cu 和SAC0705BiNi/Cu这3种无铅焊点的动态硬度、抗蠕变性能及塑性进行了对比。
不同异种钢管道焊接接头残余应力的数值模拟
图 5 0Cr18Ni9 钢材料性能 Fig1 5 Material propertie s of 0Cr18Ni9 steel
图 6 焊缝 A302 材料性能 Fig1 6 Material propertie s of A302
图 3 20 钢材料性能 Fig1 3 Material propertie s of 20 steel
72
焊 接 学 报
第 30 卷
图 10 接头 1Cr5Mo + A302 + 20 残余应力结果比较 Fig1 10 Re sidual stre ss comparison of 1Cr5Mo + A302 + 20
joint
一定的偏差 ,但是考虑到有限元离散化误差 、材料数 据偏差 、以及焊接工艺的稳定性等原因 ,这种偏差是 可以接受的 ,从而证明了模拟结果正确性.
收稿日期 : 2008 - 03 - 14 基金项目 : 江苏省六大人才基金资助项目 (06 D 035) ;江苏省高
技术重点实验室基金资助项目 (BM2007201)
与 1Cr5Mo 和 0Cr18Ni9 钢之间的焊接) ,进行焊接残 余应力的数值分析 ,并通过试验对模拟结果进行了 验证. 从残余应力的角度 ,对比分析了奥氏体 A302 焊条和镍基 Incone182 焊条.
材料的热力学性能均与温度相关 ,并且假定材 料在高温状态下物理性能 (熔点以上) 保持不变[8] . 由于熔池处的焊接温度很高 ,而一般钢材温度超过
600 ℃后的材料高温性能数据欠缺 ,在熔点与 600 ℃间用插值法获取. 2. 3 单元生死技术
在焊接过程中 ,焊材不断地填充形成焊缝 ,这一 过程可以利用生死单元技术生动地体现出来. 文献 [ 9 ]表明应用生死单元方法加载 ,能够有效地模拟焊 缝的形成过程和焊接热载荷的输入 ,而且这种方法 较构造焊接热流密度函数简单 ,更适用于复杂结构 的焊接过程模拟 ,且计算效率和精度均较高. 开始
不同加载速率下木材失效行为的多尺度数值分析
不同加载速率下木材失效行为的多尺度数值分析钟卫洲;邓志方;魏强;陈刚;黄西成【摘要】基于云杉微观结构特征,建立代表体积元模型,对顺纹和横纹压缩下云杉大变形行为进行数值模拟,获得材料各向异性和宽平台应力特性.数值模拟涉及准静态、5,50,500 m/s 4种加载速率,结果表明剪切滑移和屈曲塌陷是木材顺纹压缩的主要失效模式;横纹压缩则体现为胞墙褶皱和循序塌陷.加载速率对顺纹压缩影响高于横纹方向加载,高速加载时木材在轴向压缩下呈现花瓣形破坏,而横纹压缩则表现为压缩膨胀断裂;相对于高速加载,低速加载下木材变形表现为更均匀、平稳.【期刊名称】《中国测试》【年(卷),期】2016(042)010【总页数】6页(P79-84)【关键词】云杉;多尺度模型;代表体积元;数值模拟【作者】钟卫洲;邓志方;魏强;陈刚;黄西成【作者单位】中国工程物理研究院总体工程研究所,四川绵阳621999;中国工程物理研究院总体工程研究所,四川绵阳621999;中国工程物理研究院总体工程研究所,四川绵阳621999;中国工程物理研究院总体工程研究所,四川绵阳621999;中国工程物理研究院总体工程研究所,四川绵阳621999【正文语种】中文木材微观结构由规则排列聚合物胞元构成，胞元结构排列模式导致其宏观力学行为的各向异性，形成了沿顺纹、径向和弦向3个方向材料对称轴［1-2］。
由于木材沿径向和弦向力学行为基本相似，通常采用横观各向同性本构模型近似描述其力学特性。
近年来，学者们针对木材宏观各向异性和胞元结构分布特性开展了很多研究工作［3-5］。
采用材料试验机测试准静态和低应变率力学性能和失效行为，运用Hopkinson设备测试高应变率力学性能［6-7］，通过扫描电镜观察木材胞元结构尺寸与排列分布［8-10］。
宽平台应力是木材压缩性能的典型特征，压缩作用下胞壁结构发生屈曲，当胞元空间填满后，压缩应力急剧增加［11-13］，目前已被作为缓冲材料用于放射性材料包装缓冲结构［14-15］。
论文统计 - 中南大学
论文统计1. Li ZC, Liu L, He LL, et al.，Shear-activated indentation crack in GaAs single crystal，J. Mater. Res., 16 (2001) 2845 (SCI)2. Sun WR, Guo SR, Lu ZD, Li ZC, Tong YB and Hu ZQ, A mechanism of phosphorus on the creep properties of alloy 718, The Forth Pacific Rim International Conference on Advanced Materials and Processing, Ed. By S. Hanada et al., The Japan Institute of Metals, USA, (2002) 2719. (International Conference)3. Hu ZQ, Sun WR, Guo SR, Li ZC and Lu DZ, Effect of phosphorus on deformation mechanisms and creep properties of Inconel 718 alloy, The Third International Forum on Advanced Material Science and Technology, Anshan Institute of Iron & Steel Technology, Anshan, China, June 2002. (International Conference)4. Li ZC, Liu L, Wu X, et al.，Indentation induced amorphization in gallium arsenide，Mater. Sci. Eng. A, 337 (2002) 21 (SCI)5. Li ZC, Liu L, Wu X, et al.，TEM observation of the phase transition in indented GaAs，Mater Lett., 55 (2002) 200 (SCI)6. Li ZC, Liu L, Xu YB, et al.，Electric fatigue of (BaPb)TiO3 ferroelectric ceramics，J. Mater. Sci-Mater. In Electronics 13 (2002) 225 (SCI)7. Li ZC, Liu L, Wu X, et al.，Structure at the crack tip in GaAs，Phil. Mag. Lett., 83 (2003) 217 (SCI)8. Li ZC, Zhao XK, Zhang H, et al.，Microstructure and superelasticity of severely deformed TiNi alloy，Mater. Lett., 57 (2003) 1086 (SCI)9. Kese KO, Li ZC, Bergman B，Influence of residual stress on elastic modulus and hardness of soda-lime glass measured by nanoindentation, J. Mater. Res., 19 (2004) 3109 (SCI)10. Li ZC, Zhang H, Xu YB，Direct observation of electron-beam-induced nucleation and growth in amorphous GaAs，Mater. Sci. in Semicond. Proc. 7 (2004) 19 (SCI)11. Li ZC, Zhang H, Liu L, et al.，Growth and morphology of beta phase in an Mg-Y-Nd alloy，Mater. Lett., 58 (2004) 3021 (SCI)12. Li ZC, Smuk L, Bergman B，Influence of AST additives on the stability of PTCR characteristics and microstructure in ferroelectric ceramics，J. Mater. Sci-Mater. In Electronics 15 (2004) 561 (SCI)13. Li ZC, Zhang H, Bergman B，Microstructure and PTCR effect of La-doped BaPbO3 ceramics，J. Mater. Sci-Mater. In Electronics 15 (2004) 183 (SCI)14. Kese KO, Li ZC, Bergman B, Method to account for the true contact area in soda-lime glass during nanoindentation with the Berkovich tip，Mater. Sci. Eng. A, 404 (2005) 1 (SCI)15. H. ZHANG, Z.C. LI, L. L. HE, H.Q. YE, Reciprocal space analysis of β phase precipitates in a TiAlW alloy, Mater. Sci. Eng. A, 403 (2005) 120. (SCI)16. Li ZC, Bergman B，Effect of ageing on the electrical resistivities of (Ba0.69Pb0.31)TiO3 PTCR ceramic thermistors，Ceram. Intern. 31 (2005) 361 (SCI)17. Li ZC, Bergman B，Electrical properties and ageing characteristics of BaTiO3 ceramics doped by single dopants，J. Europ. Ceram. Soc., 25 (2005) 441 (SCI)18. Li ZC, Bergman B，Thermal cycle characteristics of PTCR ceramic thermistors, Sensors & Actuators A 118 (2005) 92 (SCI)19. Li ZC, Zhang H, Zou XD, et al.，Synthesis of Sm-doped BaTiO3ceramics and characterization of a secondary phase，Mater. Sci. Eng. B, 116 (2005) 34 (SCI)20. Kese KO, Li ZC, Bergman B, Contact residual stress relaxation in soda-lime glass II: aspects relating to strength recovery，J. Europ. Ceram. Soc., 26 (2006) 1013 (SCI)21. Z.C. Li, H. ZHANG, B. BERGMAN, X.D. ZOU, Synthesis and Characterization of IT-electrolyte of La0.85Sr0.15Ga0.85Mg0.15O3-δ by Steric Entrapment Synthesis Method, J. Europ. Ceram. Soc, 26 (2006) 2357 (SCI)22. K.O. Kese and Z.C. Li, Semi-ellipse method for accounting for the pile-up contact area during nanoindentation with the Berkovich indenter, Scripta Mater., 55 (2006) 699 (SCI)23. Zhang H, Li ZC, Bergman B, Zou XD, Characterization of La9.33Si6O26 oxygen-ion conductor sintered in N2 atmosphere, JMST, (revised)24. Zhi-Cheng Li, Hong Zhang, Bill Bergman, Synthesis and Characterization of NanostructuredBi2O3-doped Cerium Oxides Fabricated by PV A Polymerization Process, J. Europ. Ceram. Soc., (submitted)25. Hong Zhang, Haitao Zhou, Bill Bergman and Zhicheng Li, Fabrication and Conductivities ofCeO2-based Oxygen-ion Conductors Doped by M2O3 (M=La, Nd, Sm and/or Ga), CICC-5 (accepted). 26. 李志成，徐永波，张静华，王中光，胡壮麒，镍基单晶高温合金的循环软化硬化行为, <95全国高温合金年会>，金属学报, 31 (1995) S294.127. 李志成，徐永波，姚向东，胡壮麒，钴基定向凝固高温合金的循环软化硬化行为, <95全国高温合金年会>，金属学报, 31 (1995) S335.28.单智伟，杨继红，刘路，李志成，谭若兵，徐永波，单晶Ni3Al裂纹扩展的TEM原位观察，金属学报，36（2000）262 .(SCI)29. 李志成，单智伟，吴亚桥，贺连龙，徐永波，压痕诱导单晶GaAs非晶转变，金属学报，36 （2000）337.(SCI)30. 郑阳，李志成，刘路，徐永波，（BaPb）TiO3铁电陶瓷的电疲劳现象，<第四届全国电子材料会议（厦门）>，《功能材料》增刊，10（2001）91031. 李志成，刘路，吴欣，贺连龙，徐永波，脆性材料中的微裂纹结构与断裂，金属学报，37 （2001）503-506 (SCI)32. 李志成，刘路，吴亚桥，徐永波，脆性材料裂纹尖端结构与断裂，中国学术期刊文摘，9（2001）116933. 李志成，刘路，贺连龙，徐永波，高压与剪切诱导砷化镓单晶相变的机制，材料研究学报，16（2002）170 (EI)34. 孙文儒，郭守仁，李志成，卢德忠，佟佰运，李娜，胡壮麒,IN718合金蠕变变形机理及磷的影响,第六届先进材料技术研讨会, 中国航空学会，材料工程专业分会，2002年11月35. 李井润，李志成，刘路，徐永波，冷轧TiNi合金的微观结构，<第十二届全国电子显微学会议(2002)>，中国电子显微协会, 21 (2002) 677.36. 李井润，李志成，刘路，徐永波, 压痕诱导GaAs单晶中的孪晶结构，材料研究学报，17 (2003) 359(EI)37. 李德辉，李志成，刘路，邹壮辉，时效对Mg-Y-Nd合金的影响，材料研究学报，17 (5) (2003)483-487.(EI)38．李志成，刘路，贺连龙，徐永波，电子束诱导非晶GaAs晶化的形核与长大，金属学报，39（2003）13-16.(SCI)39. 李井润，李志成, 徐永波，压痕诱发GaAs单晶中的位错组态, 中山大学学报，43 (2004) 43 (EI)40. 李井润，李志成, 徐永波，使用铝电极的BaPbO3陶瓷的PTCR效应, 华南理工大学学报，32 (2004）10 (EI)41. 李井润，李志成，徐永波, 压痕诱发GaAs单晶的塑性变形，电子科技大学学报，33 (2004) 59 (EI)42. 张鸿，李志成，PTCR铁电陶瓷热疲劳过程中的反常现象研究，材料导报（投稿）43. 张鸿，李志成,张锦星，Sb2O3掺杂CeO2基氧离子导电电解质材料的制备与表征，材料科学与工艺（投稿）44. 张鸿，李志成，BaTiO3铁电陶瓷时效过程中的性能稳定性研究，电子元件与材料，（接收）45．张鸿，李璐君，周海涛，王申存，李志成，氧化铋掺杂氧化铈纳米材料的合成与导电性研究，材料科学与工程学报，（revised）46. 张鸿，刘红杰，李志成, 基于Ba-Bi-Ti-O系的新型无铅PTCR热敏陶瓷材料, STC07, accepted。
纳米压痕理论在残余应力检测方面的技术进展
纳米压痕理论在残余应力检测方面的技术进展李青;刘士峰【摘要】This paper described the nano-indentation theory and two typical indentation models for characterizing the residual stress. The two models both assume that there is equal-biaxial residual stress on the specimen surface, and the model proposed by Suresh and A. E. Giannakopoulos can determine the residual stress through the contact area ratio of stressed and unstressed materials. Later, Y. H. Lee and D. Kwon modified the model, and transferred the contact area into the function of load. Therefore, the residual stress is only related to load. This paper also summarized the application examples which used the nano-indentation theory to detect residual stress. However, further research has to be made on the nano-indentation technique for detecting residual stress.%介绍了纳米压痕理论以及2种典型的测量残余应力的理论模型,这2种模型都假设表面存在等双轴残余应力.其中Suresh和A.E.Giannakopoulos模型测量残余应力是由存在残余应力时和没有残余应力时的接触面积之比来确定；随后Y.H.Lee和D.Kwon对该模型进行了修正,根据载荷与硬度的对应关系,将接触面积转换成载荷的函数；最后的残余应力计算仅与载荷有关.本文还详细综述了用纳米压痕理论检测残余应力的应用实例,最后提出用纳米压痕技术检测残余应力的可能性还有待更深入的研究.【期刊名称】《新技术新工艺》【年(卷),期】2013(000)003【总页数】3页(P118-120)【关键词】纳米压痕;理论模型;残余应力;检测【作者】李青;刘士峰【作者单位】军械工程学院,河北石家庄 050003;邢台轧辊小冷辊有限责任公司,河北邢台 054000【正文语种】中文【中图分类】TG174.44纳米压痕(nano indentation)技术又被称为深度敏感压痕(depth sensing indentation)技术，是近年发展起来的一种新技术,它可以在不分离薄膜与基底材料的情况下，直接得到薄膜材料的许多力学性质，如弹性模量、硬度、屈服强度、加工硬化指数等[1-3]，其在微电子科学、表面喷涂、磁记录及薄膜等相关的材料科学领域得到越来越广泛的应用[4-6]。
纳米压痕技术及其在薄膜涂层体系中的应用
表面技术第51卷第6期纳米压痕技术及其在薄膜/涂层体系中的应用王宇迪1，王鹤峰1,2，杨尚余1，赵帅1，金涛1，肖革胜1，树学峰1（1.太原理工大学 机械与运载工程学院，太原 030024；2.太原清泽智成科技合伙企业，太原 030024）摘要：综述了纳米压痕技术的发展历程及其在薄膜领域的应用。
介绍了当前实验室条件下主要采用的电磁驱动式纳米压痕仪的构造和工作过程。
为了保证测试结果的准确性，要在合适的温度、湿度下进行压入实验，借助保载来消除一些可以避免的误差。
阐述了压头的分类和选择原则，玻氏压头相比于维氏压头具有更小的中心线与棱面夹角，避免了尖端横刃对于压入结果准确性的影响，因此最常用的压头为玻氏压头；表征断裂韧性最合适的压头为立方角压头；表征微机电系统的弯曲采用楔形压头。
总结了通过最大载荷和压入面积得到涂层力学参量的分析流程。
归纳了将纳米压痕法应用于表征薄膜涂层的硬度和弹性模量、室温下蠕变性能、断裂韧性、残余应力、塑性性能等力学量的研究，如表征硬度和弹性模量的Oliver-Pharr法的应用，识别蠕变柔量的Lee-Radok模型的应用，分析断裂韧性的Lawn-Evans-Marshall模型的应用。
在涂层制备过程中，制备参数的改变可以使得涂层具有不同的力学性能，涂层厚度远小于表面尺寸，硬度和弹性模量仍然存在各向异性，非晶态结构涂层具有更高的硬度和弹性模量。
采用碳纳米管强化可以提高涂层的断裂韧性，涂层内存在适量的残余应力数值和合适的残余应力类型，可以改善涂层的力学性能。
具有多层结构、梯度结构等新型结构的涂层相比于传统涂层具有更优良的力学性能。
纳米压痕法结合AFM原子力显微镜可以实现原位测量，结合有限元法可以对于理论模型进行完善，并拓宽模型的适用范围。
最后，对于纳米压痕技术在薄膜涂层中的应用前景进行了展望。
关键词：纳米压痕；薄膜；涂层；力学性能；研究现状中图分类号：TG174 文献标识码：A 文章编号：1001-3660(2022)06-0138-22DOI：10.16490/ki.issn.1001-3660.2022.06.012Nanoindentation Technique and Its Application in Film/Coating SystemWANG Yu-di1, WANG He-feng1,2, YANG Shang-yu1, ZHAO Shuai1,JIN Tao1, XIAO Ge-sheng1, SHU Xue-feng1(1. College of Mechanical and Vehicle Engineering, Taiyuan University of Technology, Taiyuan 030024, China;2. Taiyuan Qingze Zhicheng Technology Partnership, Taiyuan 030024, China)收稿日期：2021–05–06；修订日期：2021–09–02Received：2021-05-06；Revised：2021-09-02基金项目：山西省回国留学人员科研资助项目（2020-030）；山西省科协项目（RZ2000004218）；山西省留学人员科技活动择优资助项目（20200028）Fund：Research Project Supported by Shanxi Scholarship Council of China (2020-030); Shanxi Science and Technology Association Project (RZ2000004218); Shanxi Province Overseas Students Science and Technology Activity Funding Project (20200028).作者简介：王宇迪（1997—），男，硕士研究生，主要研究方向为金属力学性能实验表征。
纳米压痕法测定微铸件室温蠕变应变速率敏感指数
Correspondent: REN Mingxing, Tel: (0451)86402266, E-mail: hitrmx@ Supported by National Natural Sicience Foundation of China (No.50475028)
1) School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 15001 2) Micro/Nano Technology Research Center of Harbin Institute of Technology, Harbin 150001
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三年(2022-2024)高考英语真题分类汇编：专题13 阅读理解七选五-(原卷版)
B. So, should we stop traveling?
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F. You’ll find yourself virtually alone, or close to it.
G. Consider giving back to the communities you’re visiting.
3.（2024年浙江卷1月）In the past few years, online learning has become a significant part of the university and college experience.___16___But are all online courses created equal? How can you be sure that digital learning is right for you?___17___
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Mechanical Properties of Cu6Sn5, Cu3Sn, and Ni3Sn4 Intermetallic Compounds Measured by
Intermetallic compounds (IMCs) developed on the interface between the solder alloy and its bonding pads play a crucial role in the integrity of the solder joint, and hence the reliability of electronic packages. The Cu6Sn5, Cu3Sn, and Ni3Sn4 binary IMCs are major species in a solder system with Cu or Au/Ni/Cu pad metallizations. Ternary or multielement IMCs such as (Cul-,,Ni,)6Sn5 and (Nil-y,Cuy)3Sn4 can also be frequently found because of the adoption of various Pb-free solder alloys as well as the ease of inter-substitution of Cu and Ni due to their similar atomic sizes and lattice structures [1]. It has been identified that fracturing around the interfacial IMC layer is the primary failure induced by drop impacts in particular for Pb-free solder joints [2,3]. Characterizations of mechanical properties and strengths of IMCs in the structural [4-6] or nanomechanical regime [714] have therefore attracted great interests. In this work, we present nanomechanical properties of Cu6Sn5, Cu3Sn, and Ni3Sn4 IMCs obtained by nanoindentation incorporated with the continuous stiffness measurement (CSM) [15]. For nanoindentation of IMCs, difficulties in obtaining consistent and convergent measurement results have been pointed out by Rhee et al. [7], and data variations were attributed to specimen preparation as well as test methodologies. In most of the cases, Cu-Sn and Ni-Sn IMC samples were obtained by annealing a diffusion couple that placed Sn or a certain solder paste onto a Cu or Ni substrate. A proper annealing process should be sought in order for the IMC layers to grow
仿照车前草的发明英语作文
仿照车前草的发明英语作文英文回答：The invention of Plantain, a common weed found in many parts of the world, has revolutionized the medical industry. This unassuming plant, often considered a nuisance, hasbeen discovered to possess remarkable healing properties, making it a valuable addition to the world of natural medicine.Plantain, also known as Plantago major, is a broadleaf plant that has been used for centuries in traditional medicine. Its healing abilities have been documented in ancient texts from various cultures, including the Egyptians, Greeks, and Chinese. The plant contains a wide range of beneficial compounds, including flavonoids, tannins, and mucilage, which contribute to its therapeutic effects.One of the most well-known uses of Plantain is forwound healing. The plant's leaves contain allantoin, a compound that promotes cell regeneration and tissue repair. Additionally, Plantain's antibacterial and antifungal properties help prevent infection, making it an effective natural remedy for cuts, burns, and other skin ailments.Plantain is also effective in treating digestive issues. Its mucilage acts as a soothing agent, coating thedigestive tract and reducing inflammation. This makes Plantain a useful remedy for conditions such as gastritis, ulcers, and diarrhea. The plant's laxative properties can also provide relief from constipation.In addition to its healing properties, Plantain is also a valuable source of nutrients. The leaves are rich in vitamins A, C, and K, as well as minerals such as iron, calcium, and magnesium. This makes Plantain a healthy addition to any diet, contributing to overall well-being.The invention of Plantain as a medicinal plant has hada significant impact on the healthcare landscape. This humble weed has proven to be a potent natural healer,offering a wide range of therapeutic benefits. As more research is conducted on Plantain, its potential as a natural remedy continues to expand, making it an exciting prospect for the future of medicine.中文回答：车前草的发明。
creep——精选推荐
CreepObjectiveThe objective of this laboratory is for you to observe and quantify creep deformation in an elemental polycrystalline metal and a polymer.PreparationRead sections 13.1‐13.11 of Meyers and Chawla; the introductory section of the journal article on Al(Sc) alloys; and the introductory section of the 2010 journal article on polyethylene creep.Equipment and samples•Creep apparatus with linear‐variable‐differential‐transformer (LVDT); micrometer for calibrating the LVDT.•Samples of Al and polyethylene rods.•Computer, data acquisition board, plotting software.IntroductionA.Elastic, Plastic and Creep DeformationThese notes emphasize creep deformation of metals; for more details about the microscopic mechanisms of creep deformation of polymers, see section 13.11 of Meyers and Chawla.When a material is subjected to a load at elevated temperatures it begins to irreversibly change its dimensions by creep deformation. Creep is distinguished from low temperature deformation by its time dependence. When load is first applied to a component, it undergoes virtually instantaneous elastic, and sometimes plastic strain, but zero creep strain. As time proceeds, however, the material continues to strain owing to creep. The total deformation (strain) can be expressed as,= () + () + ()el pl cεεσεσεσ(1) Where εel, εpl and εc are the elastic, plastic and creep components of strain, respectively.Creep strain is obtained by integrating the expression,=tcdtεε∫ (4)Creep can or a violin More ser the comp form of c the creep Since the to time anwhere the obtain,This functincreases time. Fo tightened Fi n also be imp n gradually lo ious consequ onent does n reep is termerate can be e total strain innd obtain, e plastic strai tion is plotte . Since the e r this reasond.igure 1. Repla portant even osen their te uences can oc notactually ch ed stress rela expressedas, n this situatio in has been n f σd in Fig. 1. N elastic stress n, bolts that acement ofe if the creep s ension with ti ccur when bo hange its dim xation. To se , c ε on is constant 1d E d neglected. By 1111 - n n i σ−−Notice that th is proportion are used in h lastic strainb strain is relat me, requiring olts loosen d mension, but t ee how this o n B σ=t, i.e. d ε/dt = = - B dt σy integrating (-1)n BE =he elastic str nal to the ela high tempera by creepstrain ively smal. F g the musicia during high te the stress on occurs, we wi 0, we can dif n σ from σ = σi Et ain decreases stic strain, th ature applica n with timea For example, ns to retune emperature s the compone ill assume for (5)fferentiate eq (6)at t = 0 to σ (7)s with time a he elastic stre tions must bt high tempe strings on a g their instrum service. Note ent decreases r the momen qn.(1) with re = σf at t = as the creep ess decreases be occasional rature [1].guitar ments. e thats. This t that espect t, we strain s withlly re ‐B. T The creep transient is illustrat creep, usu contribute during pr taking plahardening constant the grain Of most cC. S Various m diffusion, temperat to creep t temperat rule of thu We will b Generally regime is Three Stag p response of creep), secon ted in Fig. 2, ually only ste e much to th imary creep ace that mak g observed a rather quickly boundaries. concern for m teady Stat mechanisms o and this is ure?" Guitar to over 1500ure, T H , whic umb, high tem be concerned y 3 < n < 8, w given by,ges of Cree f a material c ndary (or stea where strain eady state cre e overall stra is not well un e the materi at room tem y. During ter As these voimaterials desig Figure te Creepof creep def why creep is strings creep 0 °C. Since di ch is the ratio mperature ge d in this labo where n isth epcan be divide ady state), an is plotted as eep is of impo ain or service nderstood, b al increasing mperature du rtiary creep, f ids accumulat gn, therefore,e 2. Three stag ormation ha s basically a p at room tem iffusion is inv o of the actua enerally mean oratory only e stressexpo ed into three d tertiary (or s a function o ortance since e life of a com ut it seems c ly more diffic uring tensile flaws develop te, the strain , is the secon ges of creep d ve been iden high temper mperature, w volved, it is g l temperatur ns T H > 0.5.with power onent . Thef e stages, prim r final). The fu of time. Alth the other tw mponent. Ho clear that cha cult to deform testing. The p in the micro rate acceler d stage of cre deformation [ntified. All o rature pheno hile ceramic c generally usef re to the melt law creep, w ullexpression mary (sometim ull creep resp ough there a wo stages are ow the deform anges in the m m. This is no strain rate ostructure, ty ates, and fra eep.[2].of them, how omenon. Wh components ful to refer to ting point, which is exp n for creep in mes referred ponse of a ma are three stag brief; they d mation takes microstructur ot unlike the usually falls ypically voids cture soon oc wever, depen hat denotes are often res o the homolo T H = T/T m ressed by Eq n the steady to as aterial ges of do not place re arestrain to a alongccurs. nd on "high istant ogous . As a q. (5). state0 exp n c B Q A D k T σεμ⎛⎞⎛⎞−=⎜⎟⎜⎟⎝⎠⎝⎠ . (8)Where µ is the shear modulus and b k is the Boltzmann's constant (1.381x10‐23 J/°K). Notice in eqn.(8) the terms D o exp(‐Q/k b T), which is simply the diffusion coefficient, and σn . The object of the present laboratory is to determine the values of the stress exponent, n, and activation enthalpy for creep, Q. The latter can be compared to the activation enthalpy for diffusion to check if creep and diffusion are indeed related.Session 1: Creep deformation of pure polycrystalline Al• Calibrate the LVDT using a micrometer• Measure the dimensions of the sample with micrometer and caliper.• Measure the creep strain of an aluminum sample (1100‐Al) as a function of time fordifferent applied loads and at different temperatures. You will want to measure thetemperature of the clamps at both ends of the sample and use the average of thesetemperatures to determine the temperature of your sample. At temperatures near 400 C,you will need to use a mass of approximately 1 kg. Near 530 C, you will need to use a massof approximately 400 g. The best approach will probably be to systematically increase anddecrease the mass at constant temperature.• Analyze the dependence of creep strain ‐rate on temperature and train to determine theactivation energy Q for creep and the stress exponent n . Convert displacements and loads tostrains and stresses.Session 2: Creep deformation of polyethelyene• Measure the dimensions of the sample.• Measure the creep strain of a polymer sample as a function of time for different appliedloads and at different temperatures. The TAs will provide guidance on the masses andtemperatures that are appropriate. Compare the creep deformation of polyethylene to thecreep deformation of the simple metal that you studied in session 1.Instrument proceduresCreep ApparatusThe creep apparatus is sketched below in Fig. 3. A specimen is clamped to heavy rods and placed into a furnace. Thermocouples are placed near the top and the bottom of the specimen. Weights are added to the bottom support rod outside of the furnace. A linear variable displacement transducer (LVDT) is attached to the bottom support to measure the displacement. It is important that the support rodshave high creep resistance as the LVDT measures the total displacement of the sample and the rods. We use stainless steel rods. The LVDTs have a sensitivity of ≈ 1 µm.Figure 3. Creep apparatus.Calibration of LVDTBefore you begin the experiment, the LVDT must be calibrated. Essentially the LVDT measures the change in the inductance of a coil of wire as a ferromagnetic core moves through its center. The LVDT calibration is done as follows: (a) Place one end of the ferromagnetic core of the LVDT on a micrometer head and the other end through the LVDT transformer coils; (b) Adjust the micrometer head and the position of the ferromagnetic core in the transformer coils until the LVDT output reads about ‐1200 mV/V; (c) Then record the LVDT output at regular intervals (every 1 mm) of the micrometer head movement until the LVDT output reads around +1200 mV/V. The LVDTs you will be using in this laboratory should be linear within this range; (d) A graph between the LVDT output and the micrometer head readings will result in a straight line and the slope of which will give you the LVDT calibration.References1. M.F. Ashby and D.R.H. Jones, Engineering Materials: An Introduction to their Propertiesand Application , Pergamon Press, 1st Ed, New York, 1980.2. W.F. Smith, Foundations of Materials Science and Engineering, McGraw-Hill, Inc., 2nd Ed,New York, 1993.。
布鲁克主动力学试验机 Hysitron TI 980 试验机使用说明书
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With XPM, more data can be taken in a single afternoonthan could be collected in an entire year using traditional nanoindentationmethodologies. These exclusive performance capabilities are made possibleby the coupling of three industry-leading technologies: 1) a high-bandwidthelectrostatically actuated transducer, 2) fast control and data-acquisitionelectronics, and 3) top-down in-situ SPM imaging. These synchronizedtechnologies can perform six nanoindentation measurements per second toachieve comprehensive quantitative nanomechanical property maps andproperty distribution statistics in record time.Measure More in Less TimeUltrahigh-speed quantitative mechanical property measurements (6/second)Rapid, high-resolution spatial mapping of hardness and modulus withdistribution statisticsRobust tip-area function calibration within a minute500x faster data acquisition than traditional nanoindentation testingxSol® environmental control stage compatibility for rapid testing throughput under extreme environmental conditionsSPM+ Imaging for Superior Nanomechanical T esting ResultsBruker’s pioneering scanning nanoindenters utilize the same probe to both raster the sample surfacefor topography imaging and to conduct the nanomechanical test. Using the same probe for imagingand measurement maximizes test placement accuracy, provides immediatepost-test observation of material deformation behavior, and acceleratestesting throughput.High-precision probe placement accuracy (±10 nm)Customizable SPM resolution options from 64x64 to 4096x4096Quick imaging of high-aspect-ratio features with rectangular imaging ofany X -Y resolution combinationIndustry-leading nanomechanical SPM image resolution withenhanced color palettesCompatible with additional techniques, including lateral forceimaging, nanoDMA III, nanoECR®, and xSol environmental controlB r u k e r N a n o S u r f a c e s D i v i s i o n i s c o n t i n u a l l y i m p r o v i n g i t s p r o d u c t s a n d r e s e r v e s t h e r i g h t t o c h a n g e s p e c i f i c a t i o n s w i t h o u t n o t i c e . H y s i t r o n , n a n o D M A , n a n o EC R , P e r f o r m e c h , T r i b o I n d e n t e r , T r i b o i Q , T r i b o A E , T r i b o I m a g e , T r i b o S c a n , X P M , a n d x S o l a r e t r a d e m a r k s o f B r u k e r C o r p o r a t i o n . A l l o t h e r t r a d e m a r k s a r e t h e p r o p e r t y o f t h e i r r e s p e c t i v e c o m p a n i e s . © 2017 B r u k e r C o r p o r a t i o n . A l l r i g h t s r e s e r v e d . B 1500, R e v . A 0Bruker Nano Surfaces DivisionMinneapolis, MN • USA Phone +1.952.835.6366 **********************/nanomechanical-testing。
文献检索作业
纳米压痕技术在材料科学中的应用学校：北京工业大学学号：s2012260** 姓名：TX一、课题描述纳米压痕技术，又称深度敏感压痕技术，是近几年发展起来的一种新技术。
它可以在不用分离薄膜与基底材料的情况下直接得到薄膜材料的许多力学性质。
例如，弹性模量、硬度、屈服强度、加工硬化指数等。
传统的压痕测量仅仅能够得到材料的塑性性质，而且这种测量方法只能适用于较大尺寸的试样。
随着现代微电子材料科学的发展。
试样尺寸越来越小型化，传统的硬度测量技术无法满足新材料研究的需要。
此外，材料科学家们不仅要了解材料的塑性性质, 而且需要掌握材料的弹性性质。
近年发展起来的纳米压痕技术有效地满足了科学家们的这一需要，在微电子科学、表面喷涂、磁记录以及薄膜等相关的材料科学领域得到越来越广泛的应用。
二、关键词纳米压痕、力学性能三、关键词的相关词纳米压痕的相关词：弹性模量力学性能的相关词：纳米硬度、断裂韧性四、检索式中文检索式：（纳米压痕）AND (力学性能)英文检索式：" nanoindentation " AND " mechanical property "OR " elastic modulus " 五、所选择的信息源⑴中文数据库：CNKI—中国期刊全文数据库CNKI—中国优秀硕士论文全文数据库CNKI—中国博士论文全文数据库北京工业大学硕博论文数据库⑵外文数据库:Science onlineNature 数据库APS美国物理学会数据AIP美国物理联会数据库Springer Link数据库⑶文摘数据库Web of Science (SCI)Ei compendex六、每个数据库或其他信息源的检索结果⑴中文数据库① CNKI—中国期刊全文数据库检索结果：191条曹丽琴，轩福贞，王正东，涂善东.纳米压/划痕表征激光渗氮层的弹塑性力学性能.材料热处理学报. 2011, 11②CNKI—中国优秀硕士论文全文数据库检索结果：33条高宇. 单晶Cu纳米压痕的分子动力学模拟.工程力学，2011③CNKI—中国博士论文全文数据库检索结果：17条马增胜. 纳米压痕法表征金属薄膜材料的力学性能. 湘潭大学，材料物理与化学，2011⑵外文数据库① Science online检索结果：8条Izabela Szlufarska, Aiichiro Nakano, Priya Vashishta. A Crossover in the Mechanical Response of Nanocrystalline Ceramics. Science.2005: 911-914② Nature 数据库检索结果：87条选择2篇文章:1．C. A. Schuh , J. K. Mason & A. C. Lund. Quantitative insight into dislocation nucleation from high-temperature nanoindentation experiments. Nature Materials 4,617-621 (2005)2．Hongyou Fan, Christopher Hartshorn, Thomas Buchheit, David Tallant, Roger Assink, etal. Modulus–density scaling behaviour and framework architecture of nanoporous self-assembled silicas, Nature Materials 6, 418-423 (2007)③ APS美国物理学会数据库检索结果：19条选择2篇文章:1．M. Neek-Amal and F. M. Peeters. Nanoindentation of a circular sheet of bilayer graphene. Phys. Rev. B 81, 20102．M. Wen, L. Zhang, B. An, S. Fukuyama, and K. Yokogawa . Hydrogen-enhanced dislocation activity and vacancy formation during nanoindentation of nickel. Phys. Rev. B 80, 094113,2009⑶文摘数据库①Ei conpendex检索结果：199条选择2篇文章:1．Gonzalez, Mario, Vanstreels, Kris, Urbanowicz, Adam M. Modeling the substrate effects on nanoindentation mechanical property measurement. Conference article (CA), 2009(10) 2．Pharr, G.M. ,Strader, J.H. ,Oliver, W.C. . Critical issues in making small-depth mechanical property measurements by nanoindentation with continuous stiffness measurement. Journal of Materials Research, v 24, n 3, p 653-666, 2009②Web of Science (SCI)检索结果：291条选择2篇文章1．Lu, XJ；Xiao, P；Li, HY . Effect of densification distribution on the Young's modulus of porous coatings after nano-indentation . ACTA METALLURGICA SINICA-ENGLISH LETTERS, 2012, p: 383-3902．Rodriguez, Sara A.; Alcala, Jorge; Souza, Roberto M. . The reduced modulus in the analysis of sharp instrumented indentation tests . JOURNAL OF MATERIALS RESEARCH,2012, p: 2148-2160六、总结纳米压痕技术已经成为测量小尺寸材料力学性能的常用方法，但是将它作为一种技术进行基础材料物理研究，更具有意义和价值。
纳米压痕仪PPT Nanoindentation
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THEORETICAL ANALYSIS Elastic contact problem was solved already in the history: 1882- Hertz: solution of elastic contact of two spheres with different radii 1885- Boussinesq: solved stresses and displacements in an elastic body loaded by a rigid axisymmetric indenter 1965- Sneddon: general relationship between load, displacement and contact area for any punch described as a solid of revolution of a smooth function Sneddon’s load-displacement relationship for an elastic solid can be expressed by general equation as P = αhm (1)
纳米压痕技术
纳米压痕技术（英：Nanoindentation），也称深度敏感压痕技术（英：Depth-Sensing Indentation, DSI)，是最简单的测试材料力学性质的方法之一，可以在纳米尺度上测量材料的各种力学性质，如载荷-位移曲线、弹性模量(Elastic Modulus)、硬度(Hardness)、断裂韧性(Frac ture Toughness)、应变硬化效应(Strain Hardening Effect)、粘弹性使材料发生一定弹性变形的应力也越大，即材料刚度越大，亦即在一定应力作用下，发生弹性变形越小。
弹性模量E是指材料在外力作用下产生单位弹性变形所需要的应力。
它是反映材料抵抗弹性变形能力的指标，相当于普通弹簧中的刚度。
晶体管，本名是半导体三极管，是内部含有两个PN结，外部通常为三个引出电极的半导体器件。
它对电信号有放大和开关等作用，应用十分广泛。
能隙（Bandgap energy gap）或译作能带隙，在固态物理学中泛指半导体或是绝缘体的价带（valenc e band）(价带[1]（valenc e band）或称价电带，通常是指半导体或绝缘体中，在绝对零度下能被电子占满的最高能带。
对半导体而言，此能带中的能级基本上是连续的。
全充满的能带中的电子不能在固体中自由运动。
但若该电子受它可吸收足够能量而跳入下一个容许的最高能区，从而使价带变成部分充带中留下的电子可在固体中自由运动。
)顶端至传导带(传导带（conduction band）系指半导体或是绝缘体材料中，一个电子所具有能量的范围。
这个能量的范围高于价带（valence band），而所有在传导带中的电子均可经由外在的电场加速而形成电流)（conduction band）底端的能量差距, 对一个本征半导体（intrinsic semic onduc tor）而言，其导电性与能隙的大小有关，只有获得足够能量的电子才能从价带被激发，跨过能隙并跃迁至传导带。
有限元法结合压痕法估算 BNKT 薄膜的压电应力常数
有限元法结合压痕法估算 BNKT 薄膜的压电应力常数∗王巍;苏亮;郑学军【摘要】考虑基底效应的影响,将压电应变系数与压电应力常数的关系式作为补充方程,通过有限元法结合纳米压痕法估算了横观各向同性0.85Na0.5 Bi0.5 TiO3-0.15K0.5 Bi0.5 TiO3(BNKT)薄膜的压电应力常数.在正向分析中,通过无量纲分析和有限元模拟,得到最大压痕荷载、加载曲线指数与 BNKT 薄膜压电应力常数之间的无量纲方程.在反向分析中,利用纳米压痕实验得到沉积在硅基底上 BNKT 薄膜的压痕曲线,将实验数曲线中的最大压痕荷载和加载曲线指数代入正向分析建立的无量纲方程,联立补充方程进行求解,得到多组不同误差下的解,取误差最小时相应的解 e 15=0.28 C/m2,e 31=7.72 C/m2,e 33=18.26 C/m2为 BNKT 薄膜的压电应力常数.%With assistance of the substrate effect,the piezoelectric constitution is used to establish the supplemental equation,in which the piezoelectric strain constants are related with the piezoelectric stress constants,so that the piezoelectric stress constants of transversely isotropic 0.85Na0.5 Bi0.5 TiO3-0.1 5K0.5 Bi0.5 TiO3 (BNKT)thin film can be evaluated by combining nanoindentation test with finite element method (FEM)simulation.In the forward analysis,the nanoindentation responses are simulated by using FEM to extract the numerical maximum indentation loads and the loading curve exponents,and they are used to es-tablish two dimensionless equations related with the piezoelectric stress constants of BNKT thin film /sub-strate system.In the reverse analysis,the experimental indentation curves performed on BNKT thin film in nanoindentation test are fitted as the power function to obtain the maximum indentation loads and theload-ing curve exponents,and they are substituted into the dimensionless equations.The multiple solutions are obtained by using the simultaneity of dimensionless and supplemental equations,and the combination of pie-zoelectric stress constants is taken as the ultimate solution with the smallest total error.The results show that the piezoelectric stress constants of the BNKT thin film are determined as e 1 5 = 0.28 C/m2 ,e 3 1 =7.72C/m2 ,and e 3 3 =18.26 C/m2 .【期刊名称】《湘潭大学自然科学学报》【年(卷),期】2016(038)001【总页数】6页(P15-20)【关键词】纳米压痕;压电应力常数;有限元法;横观各向同性压电薄膜【作者】王巍;苏亮;郑学军【作者单位】上海理工大学环境与建筑学院，上海 200093;湘潭大学机械工程学院，湖南湘潭 411105;湘潭大学机械工程学院，湖南湘潭 411105; 上海理工大学材料科学与工程学院，上海 200093【正文语种】中文【中图分类】TB303压电薄膜是一种用人工方法合成的，通常以沉积在基底上的形式存在，其厚度在纳米至微米量级.压电薄膜材料作为一种功能材料，具有优异的力电耦合性能，广泛应用于微电机系统中的制动器、传感器和位移器等电子元器件，还应用于微机装配、自动控制、精密仪器等领域[1,2].由于压电薄膜的广泛应用，正确表征压电薄膜的力电性能显得十分重要.压痕技术是表征材料力学性能的有效手段，传统的压痕技术通过压痕测试过程中所得到的压痕载荷、投影接触面积和压痕深度等一系列的实验数据来评价材料的力学性能[3].传统的压痕测试方法将薄膜看成各向同性材料，这样简化不能表征纳米薄膜的横观各向同性材料.Zheng等利用正反向分析，采用Berkovich形状的压头进行纳米压痕实验结合有限元的方法，表征了纳米薄膜材料的弹性力学参数[4].本文考虑基底效应的影响，将压电应变系数与压电应力常数的关系式作为补充方程，通过无量纲分析和有限元模拟研究了压电应力常数对压痕响应过程中最大压痕载荷和加载曲线指数的影响，得到最大压痕载荷、加载曲线指数与压电应力常数之间的无量纲方程.利用纳米压痕实验得到沉积在硅基底上BNKT薄膜的压痕曲线，将实验数曲线中的最大压痕荷载和加载曲线指数代入无量纲方程，联立补充方程，估算横观各向同性BNKT薄膜压电应力常数.BNKT薄膜属于横观各向同性材料，它常常以沉积在基底表面的形式存在，如图1所示.x1-x2为横观各向同性面，x3为垂直于横观各向同性面的纵向对称轴，下标1和2表示横向同性方向(T)，3表示纵向对称轴方向(L).图1(b)为膜/基底体系的压痕示意图，其中P和h分别表示压痕载荷和压痕深度，t、H和R分别是薄膜厚度以及基底的厚度和半径.纳米压痕实验中，Berkovich压头是应用较为广泛的一种，为了方便地处理压头的几何模型，可由半角为70.3°的刚性圆锥型压头来代替[4].另外，假设薄膜与基底之间的结合面为理想结合面，且压头与薄膜之间的摩擦力可以忽略不计[5].对于横观各向同性压电材料，其本构方程为[4]式中，sij为弹性顺度系数，dkj为压电应变系数，ξkl为介电系数，Dk为电位移，El为电场强度.其中压电应变系数可以由压电应力常数ekj表示为dkj=ekisji，弹性顺度系数矩阵可以描述为[4]式中，ET、EL分别表示横向和纵向弹性模量，GT、GL分别表示横向和纵向剪切模量，νTL、νLT和νT是材料的泊松比，以上七个弹性力学参数之间并非独立的，其中，νTL/ET=νLT/EL，且GT可由ET和νT表示[4].由本构方程(1)和(2)知，横观各向同性材料的特征参数包括5个弹性模量、3个压电应力常数和2个介电系数[4].本文求解的是材料的压电应力常数，而材料的特征参数有10个独立参数，因此需要对材料模型进行简化，将未知的材料特征参数的个数减少到只剩3个压电应力常数.对于横观各向同性材料，泊松比νTL和νLT之和被认为是横向面内泊松比νT的两倍[6].一般近似取νT为0.3[4].当材料的弹性模量和介电系数已知时，则横观各向同性材料未知的特征参数就只剩3个压电应力常数.2.1 压痕响应的无量纲分析当刚性的圆锥型压头压入横观各向同性块体材料时，压痕载荷F与压痕深度h之间的关系可表示为F=Ch2，其中C为比例因子[7].但是，当其压入膜/基底体系时，基底效应会导致F与h的关系不同于上述的平方关系.因此，一种修正的幂函数F=Chx被用来描述受基底效应影响下压电薄膜的压痕响应，x为考虑基底效应的加载曲线指数[8].当压头达到最大压痕深度hm时，最大压痕载荷.结合F和Fm表达式，压痕载荷F和压痕深度h可表示为[8]纳米薄膜/基底体系的压痕实验表明，最大压痕载荷Fm和加载曲线指数x是与材料参数和实验数据相关的函数[4,9].当压电纳米带材料的弹性模量和介电系数作为已知量时，影响压痕响应的独立未知材料参数有纳米薄膜的压电应力常数(e15,e31,e33)、基底的弹性模量Es、纳米薄膜的厚度t以及最大压痕深度hm.于是，Fm和x可表达为其中，Es、t和hm通过纳米压痕实验获得.为了模拟数值加载曲线，将这些参数当作已知对待，而最大压痕载荷和加载曲线指数可以通过压痕实验加载曲线提取.根据π定理[4]，对(4)和(5)式进行无量纲分析可得根据(6)和(7)式，只能解出e15/e33和e31/e33两个参数.为了确定每个压电应力常数，需要一个补充方程.压电应变系数d33是表征压电材料压电性能的参数，其与压电应力常数存在如下关系[10]其中，弹性顺度系数s13和s33可由(2)式求得，d33值通过测试可得.将方程(8)作为求解压电应力常数的补充方程.2.2 有限元模拟及无量纲方程拟合利用有限元软件ABAQUS建立二维轴对称膜/基体系的模型，网格划分如图2所示.模型中BNKT薄膜的参数t=350 nm，ET=113.5 GPa，EL=169.5 GPa，GL=60 GPa，介电系数κ11=2.04×10-10F/m，κ33=10.9×10-10F/m[9,11,12]，最大压痕深度hm为40 nm.考虑到涵盖较大的材料范围，选择较宽的材料范围0<e15/e33≤7和0<e31/e33≤7.为了计算的简便，分别考虑以下组合e15/e33=(0.1、1、3、5、7)和e31/e33=(1、3、5、7)模拟加载曲线估算压电应力常数.改变无量纲化压电应力常数，可得到如图3所示的模拟数值加载曲线.当e31/e33=1，相同压痕深度下无量纲化压痕载荷随e15/e33增大而增大.由于逆压电效应反作用于压痕过程，故所需压痕载荷增大.当e31/e33分别为3、5和7时，改变e15/e33对加载曲线具有相似的影响，如图3(b)～(d)所示.图4和图5为无量纲化最大压痕载荷和加载曲线指数x与无量纲化压电应力常数e15/e33和e31/e33之间的关系.由图4和图5知，会随着e31/e33增大而增大，x随着e31/e33增大而增大.根据图3～图5的变化规律，通过Origin软件拟合，无量纲方程(6)和(7)可以拟合成如下形式：，x=β(A,B)=L1+L2A+L3A2+(L4+L5A+L6A2)B+(L7+L8A+L9A2)B2，其中，A=e15/e33和B=e31/e33，方程(9)和(10)中拟合系数Ki和Lj(i=1,2,…,9,j=1,2,…,9)的具体数值列于表1.3.1 估算BNKT压电薄膜的压电应力常数BNKT压电薄膜的压电应力常数通过文献[13]中反向分析流程图估算.在反向分析中，通过纳米压痕实验，得到BNKT压电薄膜的纳米压痕实验曲线，从中提取出最大压痕载荷为0.515 mN，拟合实验加载曲线得到加载曲线指数为1.623.查文献得Es=130 GPa[14].常见的确定d33的方法有正向压片法、圆片弯曲法、激光干涉法、悬臂梁法和显微镜法等.其中显微镜法是目前表征薄膜压电性能最为直观、有效的方法.本课题组利用日本Seiko生产的SPI4000&SPA400HV扫描探针显微镜，对不同钾含量NBT-KBT-100x铁电薄膜的电学特性进行了测试，并且已发表文章.本文所研究的压电薄膜来自课题组之前制备的样品，其d33=64 pm/V[12].通过方程(8)、(9)和(10)求得BNKT薄膜的压电应力常数.对于每一组压电应力常数组合，由方程(8)、(9)和(10)计算出对应通过实验所得的无量纲化最大加载力、加载曲线指数x和测试所得的压电应变系数d33的三个相对误差.当三个相对误差绝对值之和mtotal最小时，对应的参数组合即为所求压电应力常数的解，如表2所列.3.2 验证解的合理性为了验证解的合理性，将S1、S2和S3对应的模拟数值加载曲线与实验加载曲线对比，如图6所示.误差最小(S3)对应的数值加载曲线最接近实验加载曲线；将S3对应的压电应力常数与文献[11]中的压电应力常数e15=0.3 C/m2，e31=7.699C/m2和e33=19.62 C/m2相比，相对误差为0.2%～6.9%.因此，本文估算的结果是合理的.在考虑基底效应的情况下，将压电应变系数与压电应力常数关系式作为补充方程，提出有限元模拟结合纳米压痕实验来确定压电薄膜压电应力常数的方法.正向分析，通过无量纲分析和有限元模拟得到了压痕响应过程中最大压痕载荷、加载曲线指数和压电应力常数之间的无量纲方程；反向分析，利用纳米压痕测试，得到BNKT 压电薄膜材料的最大压痕载荷和加载曲线指数，代入无量纲方程，结合补充方程估算BNKT压电薄膜的压电应力常数.将所求得的结果反代回有限元软件ABAQUS 得到数值加载曲线与实验加载曲线，对比发现符合较好，并与文献中报道的结果比较接近，这说明通过结合有限元模拟和纳米压痕实验可以有效地确定横观各向同性压电薄膜材料的压电应力常数.【相关文献】[1] HE J H, TE HO S, WU T B, et al. Electrical and photoelectrical performances of nano-photodiode based on ZnO nanowires[J]. Chemical Physics Letters, 2007, 435(1): 119-122.[2] ZHENG X J,CHEN Y Q,ZHANG T,et al. A photoconductive semiconductor switch based on an individual ZnS nanobelt [J]. Scripta Materialia, 2010, 62: 520-523.[3] BOCCIARELLI M, BOLZON G, MAIER G. Parameter identification in anisotropic elastoplasticity by indentation and imprint mapping [J]. Mechanics of Materials,2005,37:855-868.[4] WANG J S, ZHENG X J, ZHENG H, et al. Identification of elastic parameters of transversely isotropic thin films by combining nanoindentation and FEM analysis[J]. Computational Materials Science, 2010, 49(2): 378-385.[5] CHEN W M, CHENG Y T, LI M. Indentation of power law creep solids by self-similar indenters[J]. Materials Science and Engineering: A, 2010, 527(21): 5 613-5 618.[6] NAKAMURA T, GU Y. Identification of elastic-plastic anisotropic parameters using instrumented indentation and inverse analysis[J]. Mechanics of Materials, 2007, 39(4): 340-356.[7] ZHAO M, CHEN X, XIANG Y, et al. Measuring elastoplastic properties of thin films on an elastic substrate using sharp indentation[J]. Acta Materialia, 2007, 55(18): 6 260-6 274.[8] WANG J S, ZHENG X J, ZHENG H, et al. Evaluation of the substrate effect on indentation behavior of film/substrate system[J]. Applied Surface Science, 2010, 256(20): 5 998-6 002.[9] ZHENG H, ZHENG X J, SONG S T, et al. Evaluation of the elastic modulus of thin film considering the substrate effect and geometry effect of indenter tip[J]. ComputationalMaterials Science, 2011, 50(10):3 026-3 031.[10] DAMJANOVIC D. Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics[J]. Reports on Progress in Physics, 1998, 61(9): 1 267.[11] ISUPOV V A. Ferroelectric Na0.5Bi0.5TiO3 and K0.5Bi0.5TiO3 perovskites and their solid solutions[J]. Ferroelectrics, 2005, 315(1): 123-147.[12] ZHAN K, ZHENG X J, PENG J F, et al. Effects of potassium content on the electrical and mechanical properties of (Na1-x Kx)0.5 Bi0.5 TiO3 thin films[J]. Ceramics International, 2015, 41(3): 3 474-3 480.[13] SONG S T, ZHENG X J, ZHENG H, et al. Evaluation of engineering/piezoelectric constants of piezoelectric thin film by combining nanoindentation test with FEM[J]. Computational Materials Science, 2012, 63: 134-144.[14] ZHENG H, ZHENG X J, WANG J S, et al. Evaluation the effect of aspect ratio for Young’s modulus of nanobelt using finite element method[J]. Materials & Design, 2011,32(3):1 407-1 413.。
新高考名校试题分类汇编：专题01 阅读理解应用文记叙文(开学考试专辑) (原卷版)
4.Why does the author mention Taylor Swift’s song “Bad Blood”?
A.To stress the power of music.
B.To introduce the topic of the text.
C.To show Taylor Swift’s popularity.
C.To help other children with DBA.
D.To have an operation for her cancer
6.Which of the following can best describe Hallie Barnard?
A.Strong-minded and selfish.B.Hard-working and patient.
Maine Lobster Festival — Rockland, Maine
Rockland is the self-proclaimed (自封的) lobster capital of the world, and its annual Maine Lobster Festival provides the state’s favorite lobsters and crabs. It takes place five days each summer and includes feasting on fresh seafood, a parade and live music. The Maine Sea Goddess Coronation and the Great International Great Crate Race, where contestants jump from crate (木箱) to crate and risk falling into the cold Atlantic Ocean, are don’t-miss events.
纳米压痕法测量牙周膜不同层面弹性模量
eriodontal ligament ( PDL ) is a deformable component connecting tooth root and alveolar bone， w hich transmits orthodontic forces and moments to alveolar bone and results in tooth mobility during orthodontic treatment［ 1-2］ ． How ever， according to the previous literature and dentist experience， clinical orthodontic treatment is a longterm and iterative process， and is even accompanied by possible side effects． Furthermore， the magnitude of forces and moments is considered to be indeterminate and the biologic response to orthodontic forces is unknow n as w ell ［ 3-4］ ． Studying the material properties of PDL is fundamental for elucidating the role of PDL in absorbing the treatment load and increasing the understanding of tooth
Yang Yu Tang Wencheng
( School of M echanical Engineering， Southeast University， Nanjing 211189， China)
重读那片绿绿的爬山虎推荐书作文
重读那片绿绿的爬山虎推荐书作文英文回答：In the literary tapestry of nature appreciation, the essay "Re-encountering the Verdant Ivy" weaves a vivid and poignant tale that captures the transformative power of a childhood memory. The author's sensitive prose paints a vibrant picture of a sprawling ivy plant, its emerald tendrils cascading down an old wall, evoking a sense of wonder and nostalgia.As the narrator revisits this memory, they embark on a journey of self-discovery and reflection. The ivy becomes a symbol of their own growth and resilience, mirroring their evolution from a carefree child to a thoughtful and introspective adult. Through the ivy's steadfast presence, the author gains a renewed appreciation for the enduring beauty of nature and the importance of cherishing its gifts.The essay's language is rich and evocative, employing awide range of literary devices to create a multi-sensory experience for the reader. Imagery, metaphors, and similes bring the ivy to life, allowing readers to envision its vibrant hues, delicate textures, and captivating aura. The author's use of foreshadowing and symbolism adds depth to the narrative, hinting at the deeper meaning and significance that the ivy holds for them.Overall, "Re-encountering the Verdant Ivy" is a beautifully crafted and thought-provoking essay that explores the profound connection between nature and human experience. Its evocative language and insightful reflections invite readers to reconnect with the natural world and appreciate its transformative power.中文回答：重读那片绿绿的爬山虎。
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For various indenter probes, and at various scales, at the scale of the individual hydration products (probed at 2 mN) and at the scale of mixtures of the various phases in a cement paste (probed at 100 mN).
The fit function h(t) plotted using the mean values of E0, E1, and b calculated from the 30 s tests and from the 1 h tests.
Results through nano-indentation
Some suggestions
Difficulties in the study of cement creep Concrete creep
(still not fully understood)
Short term volumetri creep
+
Long term deviatoric creep
loading and unloading is present between dwell periods
Creep relaxation appears to subside after a few tens of seconds in the 1 h test, due to the decrease in applied stress as penetration depth increases. A viable experiment for characterizing the viscoelastic response of cementitious materials on a relatively short length scale.
2
where E and ν are the elastic modulus of the tested material and Poisson's ratio, respectively. Ei and νi are indenter's parameters (for diamond: Ei=1141 GPa and νi=0.07).
3 kind of C-S-H
Relationship between creep modulus and indentation modulus, indentation hardness and packing density
The unique scaling between contact creep modulus and packing density proves that the creep behavior of the hydrated phases of cementitious materials is fully determined by its packing density: mix design has an influence on the packing density distribution but has no influence on the scaling between contact creep modulus and packing density.
Small indents (hardly visible black dots) performed to the minimum load
A large indentation matrix performed to the maximum applied load (70 indents).
Typical 30 s nanoindentation displacement versus time plot including the fit function. The data has been time shifted so that t = t-t1.
Macro study
Time limit: Concrete creeps over decades
Heterogeneous microstructure Complex multiscale heterogeneity makes it difficult to identify the individual contribution of each constituent to the overall macroscopic behavior.
C–S–H creep mechanism: primarily nano-particle sliding.
Applied hydrostatic stress
Mixed dilatational and deviatoric stress state Gradual shift to purely dilatational stress state Increasing function of time as the porosity of the material is reduced
Creep origination: viscous behavior of calcium silicate hydrates (C-S-H) C-S-H: (1) not a well-defined compound, which exhibit significant local variations. (2)never found alone and can therefore not be probed directly macroscopically. The nanoindentation technique is well-suited: probe submicrometric volumes of material.
Short-term creep of cement paste during nanoindentation
Applied force as a function ofห้องสมุดไป่ตู้time, P(t), and the displacement into the surface as a function of time, h(t).
h(t ) 1.21 Pmax ( J (t )) cot
1 1 ( t / th ) J (t ) (1 e ) 1 E0 E1 (1 e )
Contact creep modulus C
2
P Ac
Linear relationship between contact creep modulus and indentation hardness
Creep performance of cement based composites at microscale based on nanoindentation
By Abodul 2013.12.17
Content
Testing method-nanoindentation Problems exists in the testing process Applications Microscale creep properties
Indentation modulus evaluated for hydrated phases of cement paste. “O” series with increasing loading cycles without a dwell period at the peak, “C” series tested by cyclic loading to the same load with a 120 s dwell period at the peak.
Long-term logarithmic creep and nanoindentation
Identical volume fractions and creep properties of the cement, we showed analytically that how those interfaces behave has a significant impact on the macroscopic creep behavior of the concrete.
Large indentation matrix
Individual indents was set at least ten times of their final depth (approximately 5–50 μm) to avoid a mutual influence. Load range of 0 to 20N, displacement range of 0 to 50 mm, resolutions of 100 nN and 0.04 nm,
Load applied in the nano-indentation test
Time course of a single cycle: exponential loading to the peak, dwell period (only “C” series) and linear unloading.
Indentation hardness and indentation modulus
Area of contact increased over time. Indentation hardness decrease with an increasing duration of the holding phase. Indentation modulus is unbiased by viscous effects if the unloading phase is fast enough.