Metallurgical Evaluation of a DOT-3AA Cylinder Serial No. 441106, with Pin Hole Leak

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光度法研究姜黄素金属络合物与鲑鱼精DNA的相互作用_高苏亚

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抗癌、抗病毒金属络合物在生物体内与 D N A 的作用应用荧光光度法研究了诺氟沙星铽( T b ) 络合物与 D N A的相互作用 , 据此建立了 D N A 的测定方法 , 讨论了诺氟沙星铽与 D N A 分子之间的结合方式 , 对于新药的合成、选择灵敏度高的核酸探针具有深远意义。王兴明等
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( 1. 西安医学院药学系 , 陕西西安 710021; 2. 西北大学分析科学研究所 , 陕西西安 710069)
摘要 : 采用紫外可见分光光度法研究了姜黄素 ( C U R ) 的光谱特性及其金属络合物与鲑鱼精 D N A的相互作用。
3+ 结果表明 , 在 p H值为 6. 5的 T r i s H C l 缓冲溶液中 , 姜黄素的特征吸收峰在 430 n m处 , F e C U R形成了 1∶ 3 的金属 3+ 络合物 , 其结合常数 K = 4. 326 ×104 L /m o l , 确定了 F e C U R与鲑鱼精 D N A之间有嵌插作用存在 , 其结合常数 D
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高苏亚等 : 光度法研究姜黄素金属络合物与鲑鱼精 D N A的相互作用
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次蒸馏水。 U V 2450 型紫外可见分光光度计 ; M D 100 2型电子天平 , O r i o n 酸度计。 1. 2 溶液配制 1. 2. 1 姜黄素溶液精密称取 0. 036 8 g 姜黄素于 50 m L 容量瓶中 , 加无水乙醇溶解并定容 , 摇匀得浓度为 2. 000 × 10 储存。 1. 2. 2 鲑鱼精 D N A 贮备液称取一定量的鲑鱼精 D N A , 加入少量 1 m o l /LN a C l 溶液溶解于 100 m L 容量瓶中 , 以二次蒸馏水定容至刻度 ; 在 4 ℃冰箱中储存。 1. 2. 3 缓冲溶液准确称取一定量的 T r i s ,用 H C l 溶液在酸度计上调至所需的 p H 。 1. 2. 4 F e 试剂配制 F e 浓度为 2. 000 × 10

Elemental Impurities in Drug Products Guidance for Industry元素杂质指南

Elemental Impurities in Drug Products Guidance for Industry 1成品中的元素杂质I.INTRODUCTIONThis draft guidance provides recommendations regarding the control of elemental impurities of human drug products 2marketed in the United States consistent with implementation of International Council for Harmonisation (ICH) guidance for industry Q3D Elemental Impurities 3.This draft guidance will also assistmanufacturers of compendial drug products in responding to the issuance of the United States Pharmacopeia (USP) requirement 4for the control of elementalimpurities. Specifically, this draft guidance makes recommendations on the following:本指南（草案）对于在美国上市的药品2提供关于元素杂质控制方面的建议，其内容与实施的ICH Q3D 元素杂质指南3保持一致。

本指南也协助药典药品生产商应对USP 控制药品元素杂质的相关要求4。

特别指出，本指南会对以下方面提出建议：●How applicants submitting new drug applications (NDAs) or abbreviated newdrug applications (ANDAs) for noncompendial drug products should control elemental impurities as described in ICH Q3D. ICH Q3D containsrecommendations on applying a risk-based approach to control elementalimpurities and permitted daily exposure (PDE).申请非药典药品的NDA 和ANDA 时应该如何依据ICH Q3D 进行元素杂质控制。

表面纳米化对锆合金微动腐蚀行为的

装备环境工程第19卷第11期·110·EQUIPMENT ENVIRONMENTAL ENGINEERING2022年11月重大工程装备表面纳米化对锆合金微动腐蚀行为的影响唐晨1，张伟1，李正阳2，蔡振兵2（1.中国核动力研究设计院，成都 610213；2.西南交通大学摩擦学研究所，成都 610031）摘要：目的研究N36锆合金表面纳米化层的形貌和微观结构，分析表面纳米化层的微动腐蚀机理。

方法采用超声表面滚压技术（USRP）对锆合金进行表面纳米化处理，研究不同滚压速度对表面纳米化层形貌、相组成、粗糙度、显微硬度、电化学腐蚀和微动腐蚀行为的影响。

结果USRP处理后，锆合金表面有明显的塑性变形痕迹，致使锆合金表面发生加工硬化，提高了表面的硬度。

锆合金的腐蚀电流密度相较于基体更低，最大磨损深度和磨损率均低于基体。

结论USRP处理后的锆合金晶粒细化、晶界增多，提高了锆合金的表面活性，有利于钝化膜的形成。

锆合金的磨损机理为氧化磨损和磨粒磨损的共同作用。

关键词：锆合金；超声表面滚压；表面纳米化；腐蚀；微动腐蚀中图分类号：TG172 文献标识码：A 文章编号：1672-9242(2022)10-0110-09DOI：10.7643/ issn.1672-9242.2022.11.015Effect of Surface Nanocrystallization on Fretting CorrosionBehavior of Zirconium AlloyTANG Chen1, ZHANG Wei1, LI Zheng-yang2, CAI Zhen-bing2(1. Nuclear Power Institute of China, Chengdu 610213, China; 2. Tribology Research Institute, Southwest JiaotongUniversity, Chengdu 610031, China)ABSTRACT: The morphology and microstructureof N36 zirconium (Zr) alloy surface nanocrystallization layer were studied.The frettingcorrosion mechanism of the surface nanocrystallization layer was analyzed. Ultrasonic surface rolling processing (USRP) was used to preparesurface nanocrystallization layer on Zr alloys.The effects of rolling speeds on the morphology, phase composition, roughness, hardness, electrochemical corrosion and fretting corrosion behavior of the surface nanocrystallization layer were studied. Results shows thatZralloyafter USRP present plastic deformation trace.The plastic deformation on the sur-face of Zr alloy leads to work hardening and increases the surface hardness.The electrochemical corrosion tests indicate that Zr alloy after USRP shows a lower corrosion current density compared with substrate.The wear depth and wear rate of Zr alloy af-ter USRP is lower than thatsubstrate. The Zr alloy after USRP refinegrain and increase the number of grain boundary, which im-proving the activity of Zr alloy and beneficial to form passivation film. The wear mechanism of Zr alloy after USRP is the inter-收稿日期：2021–05–27；修订日期：2021–08–02Received：2021-05-27；Revised：2021-08-02基金项目：国家自然科学基金重点项目（U2067221）Fund：The National Natural Science Foundation of China (U2067221)作者简介：唐晨（1980—），男，硕士，工程师，主要研究方向为核燃料与材料。

有关铌酸钾钠基无铅压电陶瓷的英文文献翻译

Fe掺杂的钽铌酸钾钠无铅压电陶瓷的结构和压电性能通过传统的陶瓷烧结工艺已经得到一系列的无铅压电陶瓷(1- x/2) K0.5Na0.5Nb0。

95Ta0.05O3-x/2Fe2O3，（其中x=0，0.2，0.4，0.6，0.8，1.0，2.0，3.0mol%）。

研究掺杂离子对陶瓷结构、介电性、压电性能的影响。

Fe2O3的引入，细化了晶粒尺寸、减少了微孔数、增加了陶瓷的密度，从而改善了陶瓷的压电性能和烧结特性。

陶瓷的体密度达到了稳定值，大约为4.52%g/cm3，是理论值的96%。

x=0.4mol%的样品的压电系数（d33=130pC/N）和二维的机电耦合系数（K p=37.2%）最大，这两项与未掺杂样品相比都有显著地提高。

K+、Na+的空位和陶瓷中分散的Fe离子的电荷补偿减小了畴壁运动，这可能是导致陶瓷结构和电学性能提高的原因。

低浓度掺杂时，Fe2O3被认为是碱性铌酸盐的“软性”添加物。

一、简介（K，Na）NbO3基的无铅压电陶瓷作为铅基压电陶瓷的潜在替代物，已被广泛地研究。

因为它不仅有很好的压电性能而且环保。

然而，与传统的含铅压电陶瓷相比，它离商业应用还很远。

传统的压电陶瓷如：Pb（Zr，Ti）O3和Pb（Mg1/3Nb2/3）O3-PbTiO3。

提高铌酸钾钠基无铅压电陶瓷的性能，可通过Li、Ta、Sb改性或是与其他ABO3型化合物（如：BaTiO3、SrTiO3、BiMeO3、AgNbO3、Bi0.5Na0.5TiO3）形成固溶体，在这方面人们作出了很多的努力。

这一系列陶瓷的高的压电效应，归因于立方相与单斜相的变形的相界的影响。

有报道给出铌酸钾钠基无铅压电陶瓷的压电系数很高d33>200 pC/N。

但是最后发现铌酸钾钠基陶瓷的性能的提高实际上是由于铁电立方相——单斜相的相变温度降至室温附近引起的。

这种由于替代产生的相变成为多晶相变。

然而，相变温度的变化会导致强烈的温度依赖性，对于实际应用来说这是个致命的问题。

纳米金属颗粒物原位催化英文

纳米金属颗粒物原位催化英文In-situ Catalysis of Nanometal Particles.Nanometal particles, with their unique physicochemical properties, have emerged as promising catalysts in various chemical reactions. The concept of in-situ catalysis, which involves the utilization of these nanoparticles directly at the reaction site, offers significant advantages such as improved activity, selectivity, and efficiency. In this article, we delve into the principles, applications, and challenges associated with in-situ catalysis using nanometal particles.Principles of In-situ Catalysis.In-situ catalysis refers to the use of catalysts that are generated or activated directly within the reaction mixture, rather than being added as preformed entities. In the context of nanometal particles, this approach allowsfor a more intimate interaction between the catalyst andthe reactants, leading to enhanced catalytic activity. The small size of these nanoparticles ensures a high surface-to-volume ratio, which in turn results in a greater numberof active sites available for catalysis.The catalytic activity of nanometal particles isfurther enhanced by their unique electronic and structural properties. The quantum size effects observed in nanoparticles lead to changes in their electronic structure, which can significantly alter their catalytic behavior. Additionally, the high surface energy of nanoparticles promotes their stability and prevents sintering, even at elevated temperatures, maintaining their catalytic activity over extended periods.Applications of In-situ Catalysis.The applications of in-situ catalysis using nanometal particles are diverse and span across various fields of chemistry and engineering. Some of the key applications include:1. Organic Synthesis: Nanometal particles, especially those of platinum, palladium, and gold, have found widespread use in organic synthesis reactions such as hydrogenation, carbon-carbon bond formation, and oxidation reactions. Their use in in-situ catalysis allows for more efficient and selective transformations.2. Fuel Cells: Nanometal particles, particularly those of platinum and palladium, are key components in the electrodes of fuel cells. Their in-situ catalysis promotes the efficient oxidation of fuels such as hydrogen, leading to improved fuel cell performance.3. Photocatalysis: The combination of nanometal particles with photocatalysts such as titanium dioxide offers a powerful tool for solar-driven reactions. The in-situ generation of reactive species at the interface of these materials enhances photocatalytic activity and selectivity.Challenges and Future Directions.While the potential of in-situ catalysis using nanometal particles is immense, there are several challenges that need to be addressed. One of the key challenges is the stability of these nanoparticles under reaction conditions. The aggregation and sintering of nanoparticles can lead to a decrease in their catalytic activity. To address this, strategies such as stabilization by ligands or supports, and the use of bimetallic or core-shell structures have been explored.Another challenge lies in the scale-up of these processes for industrial applications. While laboratory-scale experiments often demonstrate promising results, translating these findings to large-scale operations can be challenging due to factors such as mass transport limitations and heat management.Future research in in-situ catalysis with nanometal particles could focus on developing more robust and stable catalyst systems. The exploration of new nanomaterials with enhanced catalytic properties, as well as the optimization of reaction conditions and reactor designs, are likely tobe key areas of interest. Additionally, the integration ofin-situ catalysis with other technologies such as microfluidics and nanoreactors could lead to more efficient and sustainable catalytic processes.In conclusion, the field of in-situ catalysis using nanometal particles offers significant potential for enhancing the efficiency and selectivity of chemical reactions. While there are still challenges to be addressed, the ongoing research in this area is likely to lead to transformative advancements in catalysis and beyond.。

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锶变质AlSi7Mg0_3合金力学性能衰退的研究

试验研究特种铸造及有色合金　1998年第5期锶变质A lSi7M g0.3合金力学性能衰退的研究中国纺织大学　袁象恺Ξ　鲁薇华　王汝耀摘　要　在生产条件下研究了保温时间对锶变质A lSi7M g0.3合金力学性能的影响。

保温时间延续60m in以后,合金伸长率和冲击韧度下降了20%,抗拉强度下降了5%,而硬度未发生变化。

在此期间锶含量质量分数(0.004%～0.005%Sr)皆超过有效变质临界下限值(0.003%Sr)。

铝合金力学性能的衰退可能与吸气引起的密度降低、针孔数量增加有关。

关键词:锶变质剂　铝硅合金　衰退A Study on Fad i ng i n M echan ica l Property ofStrond iu m-m od if ied A lSi7M g0.3A lloyY uan X i angka i　L u W e ihua　W ang Ruyao(Ch i na Tex itle Un iversity)ABSTRACT　T he effect of ho lding on the m echan icl p roperty fo r Sr2m odified A lSi7M g0.3alloy has been studied under indu strial conditi on.D u ring Super2ho lding over60m in.T he lo ss of elongati on and toughness is incu rred abou t20%,com pared to lo ss of5%in ten sile strength,bu t the hardness is un2 changed w ith ti m e.In th is peri od the Sr2con ten t of0.004%～0.005%in m elt is m uch m o re than that (0.003%Sr)requ ired fo r critical m odificati on.T he m echan ical p roperty fading fo r A l2alloy w ou ld be at2 tribu ted to attribu ted low ering of den sity and increasing of p in ho le.Key W ords:Strond iu m-M od if ied,A l-Si A lloy,Fad i ng 锶变质A lSi7M g0.3合金属于高强、高韧性轻质铸造合金,广泛用于航天、航空和汽车等行业。

金属硫蛋白3对快速老化痴呆模型小鼠海马CA1区神经元细胞凋亡的阻碍

金属硫蛋白3对快速老化痴呆模型小鼠海马CA1区神经元细胞凋亡的阻碍马飞煜王凤王虎田贤先张昱【摘要】目的研究金属硫蛋白3(MT3)对快速老化痴呆模型小鼠(SAMP8)海马CA1区神经元细胞凋亡的阻碍及其机制。

方式将7月龄SAMP8小鼠随机分成6组，分为痴呆组、3种浓度的MT3组、MT1组、空白对照组。

快速老化小鼠对照(SAMR1)小鼠为正常对照组。

持续腹腔注射28 d后灌注取脑，进行海马CA1区原位结尾标记(Tunel)试剂盒和免疫组化(SP)试剂盒染色。

结果痴呆组海马CA区神经元细胞凋亡指数明显高于正常对照组。

高浓度MT3组凋亡指数最低，Bcl2蛋白表达增强，Bax蛋白表达最低(P＜，P＜。

MT3组对Bax蛋白表达的抑制作用强于MT1对照组，而二组对Bcl2蛋白表达的不同不显著。

结论 SAMP8小鼠海马结构存在大量神经元细胞凋亡，MT3通过减少Bax 表达和增加Bcl2表达，减少细胞凋亡，并有浓度依托关系；且作用强于MT1。

【关键词】 MT3；SAMP8；细胞凋亡；Bax；Bcl2第一马飞煜(1975)，女，主治医师，博士，要紧从事脑血管病及老年痴呆的研究。

阿尔茨海默病(AD)是一种神经退行性疾病，其特点性病理转变之一是脑内神经元数量的明显减少，尤其以海马结构受累最为严峻。

细胞凋亡是AD神经元丢失及其他病理学特点形成的要紧缘故。

已有研究发觉身后的AD患者脑内存在大量凋亡神经元，并有凋亡信号分子凋亡增进基因(Bax)的高表达〔1〕，而在非痴呆老年人脑内几乎无表达。

1991年，Uchida等〔2〕第一次从人脑组织中分离出金属硫蛋白3(MT3)，因其只在脑内特异表达，可能具有重要的神经生理和神经调剂功能。

临床报导AD患者脑内MT3含量明显减少〔3〕，这就引发了许多MT3与AD发病机制的研究。

快速老化痴呆模型小鼠(SAMP8)是日本Takeda等人精心培育，具有快速老化痴呆的特点，平均寿命个月〔4～6〕，是目前公认的比较理想的自然衰老痴呆模型。

纳米零价铁的制备及应用研究进展

CHEMICAL INDUSTRY AND ENGINEERING PROGRESS 2017年第36卷第6期·2208·化工进展纳米零价铁的制备及应用研究进展谢青青，姚楠（浙江工业大学化学工程学院，工业催化研究所，绿色化学合成技术国家重点实验室培育基地，浙江杭州 310032）摘要：纳米零价铁催化材料具有价格低廉、比表面积大、还原性强、吸附性和反应活性优异等优点，可通过不同机制降解各类环境污染物（如重金属、无机阴离子、放射性元素、卤代有机化合物、硝基芳香化合物、环境内分泌干扰物等），被视为一种有着广阔应用前景的新材料，是目前国内外研究的热点。

本文详细介绍了纳米零价铁的典型制备方法（如物理法、化学液相还原法、热分解法、碳热法、多元醇法等）和新型绿色合成技术，同时总结了纳米零价铁在环境污染物处理和催化方面的最新应用进展，阐述了纳米零价铁在各类反应中的作用机理和效能，并提出了纳米零价铁催化材料在实际应用中尚需解决的团聚和氧化等问题，未来的研究目标应着重于改进或开发新制备方法以降低成本和拓宽纳米零价铁催化材料的应用范围。

关键词：纳米零价铁；制备；还原；催化中图分类号：TB39 文献标志码：A 文章编号：1000–6613（2017）06–2208–07 DOI ：10.16085/j.issn.1000-6613.2017.06.034Progress of preparation and application of nanoscale zero-valent ironXIE Qingqing ，YAO Nan（College of Chemical Engineering ，Institute of Industrial Catalysis ，State Key Laboratory Breeding Base of Green Chemistry Synthesis Technology ，Zhejiang University of Technology ，Hangzhou 310032，Zhejiang ，China ）Abstract ：Nanoscale zero-valent iron catalytic materials have advantages of low cost ，high reactionactivity ，high specific surface area and excellent adsorption properties. The excellent performances of these materials in various environmental pollutants （e.g. heavy metals ，inorganic anions ，radioactive elements ，halogenated organic compounds ，nitroaromatic compounds and endocrine-disrupting chemicals ）remediation through different degradation mechanisms have made them be regarded as a new type of material that having broad application prospect. In this review ，the typical preparation methods ，including physical method ，chemical liquid phase reduction method ，thermal decomposition method ，carbothermal synthesis and polyol process ，and novel green synthesis technology ，of nanoscale zero-valent iron are introduced in detail. Moreover ，the applications as well as the reaction mechanism and efficiency of nanoscale zero-valent iron in environmental pollution treatment and catalysis are summarized. In addition ，some unresolved scientific problems including the oxidation and the agglomeration of nanoscale zero-valent iron are mentioned. It also suggests that the future research should be focused on the improvement or development of new synthetic method to reduce the cost and to extend the application field of the nanoscale zero-valent iron materials. Key words ：nanoscale zero-valent iron ；preparation ；reduction ；catalysis米零价铁的制备及其应用。

半导体β-Ga2O3中本征氧缺陷的转变能级的第一性原理计算

摘要近年来，半导体在不同条件下费米能级的确定，以及深能级缺陷对发光效率的影响等，都受到了研究人员的广泛关注。

本文中所使用的方法是以密度泛函理论为基础的第一性原理方法，采用Materials Studio 8.0中的CASTEP模块建立不同电荷的氧空位和氧间隙位的β-Ga2O3，对于不同的结构进行优化，在优化的基础上我们计算了每个结构的生成焓及形成能，并找到生成焓最低的结构，分析这些结构的晶格常数、体系总能量的变化趋势，以及形成能随费米能级的变化。

得出了三种氧空位对应的缺陷能级到价带顶之间的距离分别为VO(I) =3.31eV、VO(II)=2.70eV 和VO(III)=3，57eV。

以上距离均比1大，这种情况说明了VO均为深施主。

并由实验得出β-Ga2O3一号氧空位是深能级缺陷。

上述分析对于本实验中对影响半导体发光效率的因素进行研究探讨具有指导意义。

关键词：β-Ga2O3；第一性原理；形成能AbstractIn recent years, the determination of Fermi energy levels in semiconductors under different conditions and the effect of defects in deep energy levels on luminous efficiency have attracted extensive attention from ed in this article the method is based on density functional theory of the primary principle of method, using Materials Studio CASTEP module in the 8.0 to build different charge oxygen vacancy and interstitial oxygen beta Ga2O3, for different structure optimization, on the basis of optimized we calculated the formation enthalpy of each structure and formation energy, and find the lowest formation enthalpy structure, analyzing the structure of the lattice constant and the change trend of total energy system, and can form along with the change of Fermi level.The distances between the defect energy level corresponding to the three oxygen vacancies and the valence band top are VO(I) =3.31eV, VO(II)=2.70eV and VO(III)= 3,57 eV, respectively.The above distances are all larger than 1, which indicates that all vos are deep donors.And from the experiment, it is concluded that the oxygen vacancy of tanyi -Ga2O3 is a deep level defect.The above analysis is of guiding significance to the study of the factors affecting the efficiency of semiconductor luminescence in this experiment.Keywords: β-Ga2O3；First principle；formation energy目录第一章绪论 (1)1.1课题背景 (1)1.2半导体材料的介绍 (2)1.3半导体的缺陷 (4)1.4本文主要研究内容 (7)第二章理论基础和计算方法 (9)2.1密度泛函理论 (9)2.1.1 Hohenberg_Kohn 定理 (9)2.1.2 Kohn_Sham方程 (10)2.1.3局域密度近似和广义梯度近似 (12)2.2 Material Studio (13)2.2.1 CASTEP模块 (13)第三章 (14)3.1 构建模型 (14)3.2 β-Ga2O3的结构优化及分析 (14)第四章结论与展望 (19)4.1结论 (19)4.2展望 (19)参考文献 (21)致谢 (24)第一章绪论1.1课题背景现如今社会正在飞速发展，由于半导体可以控制材料的导电性，所以在电子技术，特别是微电子技术领域的迅猛发展做出了突出贡献。

品牌转换模型(ProductQuest)英文版

Output - Product Profile
Weight Overall liking Cocoa aroma 0.87 Cocoa flavour 0.77 Malt/Cereal aroma -0.67 Creamy texture 0.62 Bitter aftertaste -0.62 Astringent aftertaste -0.62 Sweet flavour 0.53 Soy aftertaste -0.50 Dairy/Milky aroma 0.23 Coffee flavour 0.12 Roasted aroma 0.11 Mouthcoat aftertaste 0.10
Output - Product Profile
Overall liking Sweetness Richness Colour
Strength of coffee flavour Roast taste Creaminess
Consistency
Output - Penalty Analysis
Output - Perceptual map
Evaluation Stage
Product Evaluation
Test improved products petitors Fine-tuning product to optimum level prior to launch Can include other marketing components - concept, pack, price, etc => Fine-tuning marketing mix prior to launch
PAIRED COMPARISON
Richness Too weak -1.9 18

空中客车A380飞机维修手册说明书

21644Federal Register/Vol. 65, No. 79/Monday, April 24, 2000/Rules and Regulations(2) For the purposes of these mandatory inspections, piece-part opportunity means: (i) The part is considered completely disassembled when accomplished in accordance with the disassembly instructions in the manufacturer’s engine manual; and (ii) The part has accumulated more than 100 cycles in service since the last piece-part opportunity inspection, provided that the part was not damaged or related to the cause for its removal from the engine.’’(b) Except as provided in paragraph (c) of this AD, and notwithstanding contrary provisions in section 43.16 of the Federal Aviation Regulations (14 CFR 43.16), these mandatory inspections shall be performed only in accordance with the Airworthiness Limitations Section of the manufacturer’s ICA.Alternative Methods of Compliance(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Engine Certification Office (ECO). Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector (PMI), who may add comments and then send it to the ECO.Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the ECO.Ferry Flights(d) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR21.197 and 21.199) to operate the airplane toa location where the requirements of this AD can be accomplished.Continuous Airworthiness Maintenance Program(e) FAA-certificated air carriers that have an approved continuous airworthiness maintenance program in accordance with the record keeping requirement of §121.369(c) of the Federal Aviation Regulations (14 CFR 121.369 (c)) must maintain records of the mandatory inspections that result from revising the Airworthiness Limitations Section of the Instructions for Continuous Airworthiness (ICA) and the air carrier’s continuous airworthiness program. Alternately, certificated air carriers may establish an approved system of record retention that provides a method for preservation and retrieval of the maintenance records that include the inspections resulting from this AD, and include the policy and procedures for implementing this alternate method in the air carrier’s maintenance manual required by §121.369(c) of the Federal Aviation Regulations (14 CFR121.369(c)); however, the alternate system must be accepted by the appropriate PMI and require the maintenance records be maintained either indefinitely or until the work is repeated. Records of the piece-part inspections are not required under§121.380(a)(2)(vi) of the Federal Aviation Regulations (14 CFR 121.380(a)(2)(vi)). All other Operators must maintain the records of mandatory inspections required by the applicable regulations governing theiroperations.Note 3: The requirements of this AD havebeen met when the engine manual changesare made and air carriers have modified theircontinuous airworthiness maintenance plansto reflect the requirements in the enginemanuals.(f) This amendment becomes effective onOctober 23, 2000.Issued in Burlington, Massachusetts, onApril 14, 2000.Jay J. Pardee,Manager, Engine and Propeller Directorate,Aircraft Certification Service.[FR Doc. 00–10157 Filed 4–21–00; 8:45 am]BILLING CODE 4910–13–UDEPARTMENT OF TRANSPORTATIONFederal Aviation Administration14 CFR Part 71[Airspace Docket No. 99–AAL–18]Revision of Class E Airspace;Unalaska, AKAGENCY: Federal AviationAdministration (FAA), DOT.ACTION: Final rule.SUMMARY: This action revises Class Eairspace at Unalaska, AK. Theestablishment of a Global PositioningSystem (GPS) instrument approachprocedure at Unalaska Airport madethis action necessary. This rule providesadequate controlled airspace for aircraftflying IFR procedures at Unalaska, AK.EFFECTIVE DATE: 0901 UTC, June 15,2000.FOR FURTHER INFORMATION CONTACT: BobDurand, Operations Branch, FederalAviation Administration, 222 West 7thAvenue, Box 14, Anchorage, AK 99513–7587; telephone number (907) 271–5898; fax: (907) 271–2850; email:/at or ataddress http://162.58.28.41/at.SUPPLEMENTARY INFORMATION:HistoryOn November 19, 1999, a proposal toamend part 71 of the Federal AviationRegulations (14 CFR part 71) to revisethe Class E airspace at Unalaska, AK,was published in the Federal Register(64 FR 63261). The proposal wasnecessary due to the establishment of aGPS instrument approach procedure atUnalaska, AK. Interested parties wereinvited to participate in this rulemakingproceeding by submitting writtencomments on the proposal to the FAA.No public comments to the proposalwere received; thus, the rule is adoptedas written.The area would be depicted onaeronautical charts for pilot reference.The coordinates for this airspace docketare based on North American Datum 83.The Class E airspace areas designated as700/1200 foot transition areas arepublished in paragraph 6005 in FAAOrder 7400.9G, Airspace Designationsand Reporting Points, dated September1, 1999, and effective September 16,1999, which is incorporated byreference in 14 CFR 71.1. The Class Eairspace designations listed in thisdocument will be publishedsubsequently in the Order.The RuleThis amendment to 14 CFR part 71revises the Class E airspace at Unalaska,AK, through the establishment of a GPSinstrument approach. The area will bedepicted on aeronautical charts for pilotreference. The intended effect of thisrule is to provide controlled airspace forIFR operations at Unalaska, AK.The FAA has determined that thisregulation only involves an establishedbody of technical regulations for whichfrequent and routine amendments arenecessary to keep them operationallycurrent. It, therefore—(1) Is not a‘‘significant regulatory action’’ underExecutive Order 12866; (2) is not a‘‘significant rule’’ under DOTRegulatory Policies and Procedures (44FR 11034; February 26, 1979); and (3)does not warrant preparation of aregulatory evaluation as the anticipatedimpact is so minimal. Since this is aroutine matter that will only affect airtraffic procedures and air navigation, itis certified that this rule will not havea significant economic impact on asubstantial number of small entitiesunder the criteria of the RegulatoryFlexibility Act.List of Subjects in 14 CFR Part 71Airspace, Incorporation by reference,Navigation (air).Adoption of the AmendmentIn consideration of the foregoing, theFederal Aviation Administrationamends 14 CFR part 71 as follows:PART 71—DESIGNATION OF CLASS A,CLASS B, CLASS C, CLASS D, ANDCLASS E AIRSPACE AREAS;AIRWAYS; ROUTES; AND REPORTINGPOINTS1. The authority citation for 14 CFRpart 71 continues to read as follows:Authority: 49 U.S.C. 106(g), 40103, 40113,40120; E.O. 10854, 24 FR 9565, 3 CFR, 1959–1963 Comp., p. 389.21645 Federal Register/Vol. 65, No. 79/Monday, April 24, 2000/Rules and Regulations§71.1[Amended]2. The incorporation by reference in 14 CFR 71.1 of Federal Aviation Administration Order 7400.9G, Airspace Designations and Reporting Points, dated September 1, 1999, and effective September 16, 1999, is amended as follows:* * * * *Paragraph 6005Class E airspace extending upward from 700 feet or more above the surface of the earth.* * * * *AAL AK E5Unalaska, AK [Revised] Unalaska Airport(Lat. 53°53′57″ N., long. 166°32′ 42″ W.) Dutch Harbor NDB(Lat. 53°54′19″ N., long. 166°32′57″ W.) That airspace extending upward from 700 feet above the surface within 6.4-mile radius of the Unalaska Airport and within 2.9 miles each side of the Dutch Harbor NDB 360°bearing extending from the 6.4-mile radius to 9.5 miles north of the airport; and that airspace extending upward from 1,200 feet above the surface within 20-mile radius north of the airport between the Dutch Harbor NDB 305° bearing extending clockwise to the 075°bearing.* * * * *Issued in Anchorage, AK, on April 14, 2000.Anthony M. Wylie,Acting Manager, Air Traffic Division, Alaskan Region.[FR Doc. 00–10015 Filed 4–21–00; 8:45 am] BILLING CODE 4910–13–PDEPARTMENT OF JUSTICEDrug Enforcement Administration21 CFR Part 1310[DEA Number 199F]RIN 1117–AA52Placement of Gamma-Butyrolactone in List I of the Controlled Substances Act (21 U.S.C. 802(34))AGENCY: Drug Enforcement Administration, Justice.ACTION: Final rule.SUMMARY: Public Law 106–172, signed into law on February 18, 2000, and known as the ‘‘Hillory J. Farias and Samantha Reid Date-Rape Drug Prohibition Act of 1999,’’ amends section 102(34) of the Controlled Substances Act as amended (CSA) by designating gamma-butyrolactone (GBL), the precursor to gamma-hydroxybutyric acid (GHB), as a List I chemical. Reflecting this change in stature, the Drug Enforcement Administration (DEA) is amending itsregulation to reflect the status of GBL asa List I chemical subject to therequirements of the CSA and itsregulations. Establishment of athreshold for GBL will be the subject ofa separate rulemaking. Therefore, unlessand until a threshold is established, anydistribution of GBL is a regulatedtransaction as described by 21 CFR1300.02(b)(28). All handlers of GBLmust comply with the CSA regulatoryrequirements pertaining to List Ichemicals as described in the body ofthis document.FOR FURTHER INFORMATION CONTACT:Frank L. Sapienza, Chief, Drug andChemical Evaluation Section, Office ofDiversion Control, Drug EnforcementAdministration, Washington, DC 20537.DATES: Effective: April 24, 2000.Registration application deadline:DEA must receive a properly completedDEA–510 registration application withfee from handlers of GBL on or beforeJuly 24, 2000.SUPPLEMENTARY INFORMATION:What Is DEA Doing and Whom Does ItEffect?GBL is gamma-butyrolactone, theprecursor used in the clandestineproduction of gamma-hydroxybutyricacid (GHB). This Final Rule deals solelywith amending 21 CFR 1310.02(a) toreflect that GBL is a List I chemical asestablished by Public Law 106–172.Consequently any person who imports,exports, or distributes GBL must registerwith DEA and make required recordsand reports.What Authority Does DEA Have To DoThis?On February 18, 2000, Public Law106–172 was enacted. This law requiresthe Attorney General (AG) to addgamma-hydroxybutyric acid (GHB) toSchedule I no later than April 18, 2000.Effective on February 18, 2000, Congressalso specifically designated the GHBprecursor, gamma-butyrolactone (GBL)as a List I chemical.Why Is This Being Published as a FinalRule?This publication amends 21 CFR1310.02(a) to reflect the fact thatCongress made GBL a List I chemical.For regulatory purposes, this actionleaves DEA no discretion. Therefore,DEA is publishing this action as a FinalRule.Why Was Control of GBL Necessary?Law enforcement authorities haveidentified GBL in many GHBclandestine laboratories anddocumented its use as a precursor in theclandestine synthesis of GHB. There areno chemical substitutes for GBL as aprecursor in the clandestine synthesis ofGHB. Congress recognized that controlof GBL as a List I chemical is necessaryto prevent diversion for use in the illicitproduction of GHB and made it a ListI chemical. This Final Rule amends 21CFR 1310.02(a) to reflect the fact thatGBL is a List I chemical subject to therequirements of the CSA and itsregulations.Is GBL Subject to Any Other ControlsUnder the CSA?In addition to GBL functioning as achemical precursor for the manufactureof GHB, it also produces psychoactiveeffects. If taken for human consumption,GBL and other chemicals, including 1,4-butanediol, are swiftly converted intoGHB by the body. Abuse of these andother GHB-like substances is asignificant law enforcement and publichealth problem. GBL and 1,4-butanediolare structurally and pharmacologicallysimilar to GHB and are often substitutedfor GHB. Under certain circumstancesthey may satisfy the definition of acontrolled substance analogue (21U.S.C. 802(32)). Congress expresslycontemplated this possibility byamending 21 U.S.C. 802(32) to state thatthe designation of GBL or any otherchemical as a Listed chemical does notpreclude a finding that the chemical isa controlled substance analogue andsubject to the provisions of 21 U.S.C.813.Is There a Threshold for Transactionsin GBL?Public Law 106–172 did not establisha threshold for regulated transactionsinvolving GBL. Therefore, the DEA isreviewing available data, including thatprovided by commenters in response tothe Federal Register publication‘‘Industrial Uses and Handling ofGamma-butyrolactone; Solicitation ofInformation’’ (63 FR 56941), regardingan appropriate threshold. This will bethe subject of a separate rulemaking andwill provide an opportunity for publiccomment. Until and unless a thresholdis established, all covered transactionsinvolving any amount of GBL aresubject to the CSA regulatoryrequirements.Each regulated person who engages ina regulated transaction involving GBLmust keep a record of the transactionand file reports under certaincircumstances (21 CFR 1300.02(b)(28)).If a threshold is established for GBL, therecordkeeping and reportingrequirements will only apply totransactions, including cumulative。

具有奇异特性的近藤稀土硼化物SmB6研究进展进展

具有奇异特性的近藤稀土硼化物SmB6研究进展进展SmB6是上世纪60年代就开始研究的经典近藤（Kondo）稀土硼化合物，其令人困惑的低温电阻平台一直是强关联物理领域研究的一个重要问题。

近年随着奇异的低温量子振荡和与体绝缘态共存的金属表面态在SmB6中的发现，使其重新成为研究热点。

最近，中国科学院物理研究所/北京凝聚态物理国家实验室（筹）超导实验室孙力玲研究员与合作者提出了SmB6在低温下呈现出的一系列奇异性的低温现象均源自其Sm离子中f电子独特的构型与其所处的具有“负膨胀”特性的B6框架结构在不同温度下相互作用导致的特殊的价态变化，使其基态处于一种不稳定的“伴随型”价态涨落，即由f电子构型所决定的磁性Sm离子数量与传导电子的数量在涨落中同时增加或减少，这与常见的其它磁性离子价态变化中的情况完全不同。

在稀土六硼化物中，只有SmB6和YbB6具有这种特殊的价态涨落形式。

这一新观点以“Puzzle maker in SmB6: accompany type of valence fluctuation state”为题作为Key issue review文章发表在Reports on Progress in Physics (RoPP 80，112501, 2017)上。

上述观点的提出是基于近年来她和博士生周亚洲（与赵忠贤院士联合培养）与物理所杨义峰研究员、孙培杰研究员等以及人民大学俞榕教授和美国Rice大学斯其苗教授合作，对加州大学Z. Fisk教授组提供的高质量SmB6和YbB6单晶样品进行的一系列高压下电阻、磁阻、Hall测量以及高压同步辐射XRD和吸收等多种原位手段的协同研究所取得的实验结果和深入分析。

在对SmB6的极低温高压研究中发现，在4 GPa的压力下SmB6发生了由常压奇异量子态到具有重费米子行为的量子态转变，澄清了SmB6在4 GPa压力下其基态是非费米液体还是费米液体的长期争论。

此外，还揭示了SmB6中奇异拓扑表面态消失的临压力与价态变化的内在关联性，并给出了高压相图中不同的电子态与价态、Hall系数及能隙随压力演化的对应关系。

211000528_硼氮掺杂对立方ＰｂＴｉＯ３电子结构和光学性质影响的第一性原理研究

（－１３２５ｅＶ）［３］非常一致这表明本文所选的计
算参数是准确可行的
ｌｅ１ＴｈｅｃａｌｃｕｌａｔｅｄｌａｔｔｉｃｅｐａｒａｍｅｔｅｒｓｆｏｒｃｕｂｉｃＰＴＯ
黄彬荣１，文志勤１，卢涛仪１，邹正光１，赵宇宏２
（１桂林理工大学材料科学与工程学院，桂林５４１００４；２中北大学材料科学与工程学院，太原０３００５１）
摘要：钛酸铅（ＰＴＯ）因具有优异的铁电、压电特性及光学性质而备受关注但Ｂ、Ｎ掺杂对顺电相ＰＴＯ
电子结构和光学性质的影响还不明确，因此，利用第一性原理对立方ＰＴＯ开展准确的性质预测尤为必要
ＰＴＯ体系结构、能带、态密度和光学性质的影响．
２计算方法与模型
３
结果与讨论
本文使用基于的（ＤＦＴＶＡＳＰＶｉｅｎｎａＡｂｉｎｉｔｉｏ
）程序包执行所有计算，ＳｉｍｕｌａｔｉｏｎＰａｃｋａｇｅ
［１５，１６］
并采用投影缀加平面波（ＰＡＷ）法描述离子实和价
３１本征ＰＴＯ结构弛豫计算的本征立方ＰＴＯ的晶格常数和键长如表
钛酸铅（ＰＴＯ）是一种典型的ＡＢＯ３型钙钛矿铁电材料［１］，具有较强的铁电、压电和较大的电光
似（ＧＧＡ）［８］进行计算为获得真实的带隙值，采
用杂化泛函（ＨＳＥ０６
）描述［１８］
ＰＴＯ
体系的交换关
系数，因而在非易失性存储器、传感器和驱动器联泛函，以更精确计算其电子和原子结构同时，
等方面广泛应用［２－４］ＰＴＯ在制备和退火过程中，
（ＢＯ）或Ｎ掺杂（ＮＯ）或Ｏ空位（ＶＯ）
本文采用基于密度泛函理论的第一性原理方法计算了立方ＰＴＯ体系在Ｂ、Ｎ替位及Ｏ空位时的基态性质和缺陷形成能，研究了这些点缺陷对

金属纳米粒子再分散法测定二氧化铈稳定的单原子的位点数

Department of Chemical Engineering and SUNCAT Center for Interface Science and Catalysis, Stanford University, Stanford, California 94305, United States
© 2020, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.
1. Introduction
Single atom catalysts have attracted significant interest in recent years due to their ability to maximize the utilization of expensive noble metals [1,2] as well as the unique catalytic properties single atoms provide when compared to metal nanoparticles [3–7]. However, single atom catalysts are particularly vulnerable to agglomeration of metal atoms to form nanoparticles under reaction conditions [8]. It is also difficult to produce high metal loadings of single atoms to the exclusion of metal nanoparticles [8]. In order to become industrially relevant, procedures must be developed that are capable of producing high loadings of stable single atoms. Several groups have developed protocols to produce such catalysts with metal

09-0559-W Lane Departure Warning (LDW) Performance Evaluation

LANE DEPARTURE WARNING (LDW) PERFORMANCE EVALUATIONGarrick J. Forkenbrock and Frank S. Barickman National Highway Traffic Safety AdministrationPaper 09-0559ABSTRACTThis paper describes a test track based lane departurewarning (LDW) evaluation performed by theNational Highway Traffic Safety Administration(NHTSA). NHTSA defines an LDW system as oneintended to alert the driver when their vehicle isabout to drift beyond a delineated edge line of theircurrent travel lane. LDW system alerts consist ofaudible, visual, and/or haptic warnings, or anywas designed to emulate a lateral drift whiletravelling on a straight road. This type of maneuverwas chosen because it represents one of the mostdominant pre-crash scenarios as reported in the 2004General Estimates System (GES) database.LDW performance was quantified by considering the vehicle’s proximity and approach rate to the inboard edge of a single lane line at the time of the LDW alert. Variations in how the alerts were presented to the driver, and the manner in which the timing of the alerts changed as a function of the lateral velocity toward the lane line, were observed.BACKGROUND During mid to late 2008, NHTSA performed an evaluation of the lane departure warning (LDW) systems installed on three late model passenger cars. All tests were performed by researchers at theagency’s Vehicle Research and Test Center (VRTC), located on the Transportation Research Center, Inc. (TRC) proving grounds in East Liberty, OH.NHTSA defines an LDW system as one intended toalert the driver when their vehicle is about to driftbeyond a delineated edge line of their current travellane. Contemporary LDW systems use forward-looking cameras, in conjunction with algorithmsdesigned to compare predictions of the vehicle pathand lane of travel. If a departure is deemedimminent, an LDW alert is presented to the driver.LDW alerts consist of audible, visual, and/or hapticwarnings, or any combination thereof.At the time the work discussed in this paper wasperformed, the number of US-production lightvehicles available with LDW was quite low, with only four vehicle manufacturers known to offer such systems on limited variants of certain vehicle makes and models. Of these manufacturers, only three offered systems able to initialize and perform on a road where only one lane line was present. So as to best evaluate the current state of LDW technology implementation, sample offerings from each of these three vehicle manufacturers were procured: a 2008 BMW 528i, 2009 Buick Lucerne, and a 2008 Infiniti EX35. Although it is believed each of the LDW systems installed in these vehicles have been designed to address the pre-crash scenario described in this paper, the manner in which the respective cues were presented differed, as shown in Table 1. Table 1. LDW Alert Modality LDW Alert Vehicle Audible Visual Haptic BMW 528i None NoneVibratingsteering wheel Buick Lucerne Repeated tones Flashing icon oninstrument panel (amber)None Infiniti EX35 Repeated tones*Flashing icon oninstrument panel (amber) None *The Infiniti EX35 LDW alert remains on during the entire lanedeparture event (not just when it is first detected). THE ROAD DEPARTURE CRASH PROBLEM The Early Edition of Traffic Safety Facts 2007 reports that there were 22,054 fatal single vehicle police reported crashes. This represents 59 percent of all fatal police reported crashes in 2007. Of the 22,054 fatal single vehicle crashes, over 15,000 were reported to be off roadway, on the shoulder, or on the median [1]. NHTSA has long recognized that single-vehicle road departure (SVRD) crashes lead to more fatalities than any other crash type [2]. In an analysis of the 2004 General Estimates System (GES) data, Volpe (part of DOT's Research andInnovative Technology Administration) reported that there were approximately 5,942,000 police reported crashes that involved at least one light vehicle. These crashes involved over 15,000,000 people and resulted in 2,737,000 injuries. From this target population, 36 pre-crash scenarios were identified that attributed to 99.4 percent of all light-vehicle crashes. A 37th pre-crash scenario is recognized as ‘other’ but accounts for only 0.6 percent of all crashes [3].One of the most dominant pre-crash scenarios identified by Volpe was “Road Edge Departure without Prior Vehicle Maneuver” (REDPVM). This pre-crash scenario was reported to rank fifth in overall crash frequency attributing to approximately 333,706 crashes. Additionally, REDPVM ranked third highest in direct economic cost to society estimated to cost over $9M and was ranked second highest with 270,000 functional years lost [3]. Volpe defines the typical REDPVM scenario to be associated with a light vehicle travelling straight in a rural area at night, normal weather conditions, at posted speeds of 55 mph or greater, and departing the road edge at a non-junction area. Volpe recognizes that this pre-crash scenario occurs with several dynamic variations. Approximately 26 percent of these crashes were found to occur when the vehicle was negotiating a curve and 27 percent were found to occur at the road shoulder or parking lane. Out of all the REDPVM crashes, two-thirds were found to depart the road edge to the right [3].Based on the crash frequency, cost, and functional years lost (a measure of harm) data, NHTSA decided that the use of a test maneuver designed to emulate these real-world crash scenarios would provide an appropriate way to evaluate LDW performance. Building on the efforts put forth by previous field operational tests and the Integrated Vehicle-Based Safety Systems (IVBSS) programs, NHTSA researchers subsequently developed an objective test procedure to perform the work described in this paper. The objectives of this work were twofold: (1) identify the US-production based LDW alert criteria as presented to the driver with respect to the road edge line, and (2) refine the test procedures to enhance the accuracy, repeatability, and/or reproducibility by which the LDW system evaluations could be performed.TEST METHODOLOGYOverviewThe tests described in this paper were designed to evaluate the ability of an LDW system to detect, and alert the driver of, an imminent lane departure. The tests were each performed at a constant speed of 45 mph (72.4 kph), with two departure directions (left, right), and over a range of departure rates. All tests were based on straight road departures made across a single continuous solid white lane line. LDW performance was quantified by considering the vehicle’s proximity and approach rate to the inboard edge of the lane line at the time the LDW alert was first presented.The tests were each performed on the Transportation Research Center Inc. (TRC) Vehicle Dynamics Area (VDA) located in East Liberty, Ohio. The VDA measures 1800 by 1200 ft (549 by 366 m), and is comprised of a flat asphalt surface with a one percent longitudinal grade for drainage. The pavement of the VDA used for the LDW evaluations was in good condition, free from potholes, bumps, and excessive cracks. The north turn-around loop, shown in Figure 1, was used to maximize the length of the LDW test course. All tests were performed during daylight hours with good visibility (no fog, rain, snow). The ambient temperatures and wind speeds present during the BMW 528i and Buick Lucerne evaluations ranged from 75 to 81 ºF (24 to 27 ºC) and 1 to 4 mph (2 to 6 kph), respectively. During tests performed with the Infiniti EX35, the ambient temperatures and wind speeds were 38 to 49ºF (3 to 9 ºC) and 6 to 17 mph (10 to 27 kph), respectively.InstrumentationThe test vehicles were each equipped with instrumentation and data acquisition systems to monitor and record vehicle speed, lateral and longitudinal position (via GPS), yaw rate, and LDW alert status. All analog data was sampled at 200 Hz. Signal conditioning of these data consisted of amplification, anti-alias filtering, and digitizing. Amplifier gains were selected to maximize thesignal-to-noise ratio of the digitized data. GPS data were sampled at 20 Hz, and were differentially Figure 1. Orientation of the LDW test courseon the TRC VDA (not to scale).Turn-around loopLDW straight road test coursecorrected during post-processing. To facilitate comparison of the position of the test vehicle with respect to the inboard lane line edge, GPS-based static surveys of the lines were performed. All data, including the analog and GPS-based data from the test vehicle and a static lane line survey, were then merged into a single data file per trial for the ease of subsequent data analysis. Appendix Table A1 provides a summary of the instrumentation used during the LDW evaluations discussed in this paper. In addition to this equipment, a dashboard-mounted display was used to present the driver with accurate vehicle speed information.LDW Alert MonitoringWhen activated, the LDW systems discussed in this paper provided the driver with auditory, visual,and/or haptic alerts. Recording when these alerts first occurred was important since this information would provide the points in time for which the vehicle’s lane position and rate of approach would be reported, the objective measures by which LDW performance was quantified. The methods used to record the LDW alerts differed from vehicle to vehicle, as shown in Table 2.Table 2.LDW Alert Monitoring Methods Vehicle MonitorBMW 528i Direct tap of the motor used to vibrate the steering wheelBuick Lucerne Direct tap of the speakers installed behind the left and right a-pillar trimInfiniti EX35 Direct tap of the piezoelectric speaker mounted to the back of the instrument panelBMW 528iOf the vehicles discussed in this paper, only the BMW 528i presented the driver with a haptic alert to warn of an impeding lane departure. This alert, vibrations transmitted to the driver’s hands, originated from a small motor attached directly to the steering wheel. To monitor the state of this alert, researchers directly tapped the leads supplying voltage to this motor. Note: Safety precautions required the steering wheel-based airbags be removed prior to installing the programmable steering machine. In the case of the BMW 528i, removing the steering wheel also disabled the LDW alert. Retaining LDW alert functionality while evaluating the vehicle with the steering machine installed required NHTSA researchers to request and receive assistance from BMW.Buick LucerneThe LDW installed in the Buick Lucerne presented alerts via small speakers installed behind the left andright a-pillar trim. The alerts were directional; a left lane departure would produce an alert heard predominately from the left speaker, whereas right departures produced alerts most apparent from the right speaker. The speakers were also used as part of the vehicle’s audio system; however it was not necessary to have the audio system on for the LDW alert to be heard by the driver.To monitor the LDW alert during evaluation of the Buick Lucerne, researchers directly tapped the leads of both speakers, collecting data from each speaker independently. Figure 2 presents an example of the LDW alert flag recorded for the Buick Lucerne. Note that while the duration of the alert shown in this figure was believed to be accurate, the data trace does not accurately portray how the alert was presented to the driver (i.e., as it actually consisted of a series of three beeping tones, not a single continuous alert). This is because the speaker tap used to monitor the Buick Lucerne LDW status was not designed to monitor the frequency content of the signal, just to show the speakers received DC voltage, indicating the presence of an alert.Infiniti EX35For the Infiniti EX35, the LDW alert was presented to the driver via a piezoelectric speaker installed behind the center console trim. To access thisspeaker, much of the components housed in the console had to be removed (e.g., trim, the radio, navigation and climate controls, etc.). To record the LDW alert, the speaker leads were directly tapped, and the signal that activated the piezoelectric speaker, shown in Figure 3, was recorded. In addition to the LDW alert speaker tap, an external microphone was positioned near the speaker, and its output recorded. In the case of the Infiniti EX35, installation of the external microphone allowed researchers to assess the feasibility of using a microphone to monitor the piezoelectric speaker output (the speaker design was different from that of the Buick Lucerne), and to provide a redundant LDW alert monitor. However, the microphone-based alert data were not used during subsequent data processing or analyses.Lateral Velocity RangesThe lane departures described in this paper occurred over a range of lateral velocities intended to represent unintended drifts. When considering the severity of these tests, it is important that the reader recognize these are gradual transitions from the lane of travel over the line of interest. In the context of this paper, the term “lane change” should not be confused with the far more severe maneuvers used to assess obstacle avoidance capability, lateral stability, or dynamic rollover resistance.Lane Line MarkingsTo insure maximum relevancy, the 4 in. (10.2 cm) lane marker width, marking color and reflectivity, and line styles satisfied the USDOT specifications required by the Manual on Uniform Traffic Control Devices (MUTCD), and were in “very good condition” [4]. The lane departures described in this paper each occurred over a continuous solid white line.Test Configurations and ConductTo emulate a common pre-crash lane departure scenario, researchers evaluated LDW performance using a test course based on a straight road. All tests described in this paper were performed with a constant nominal speed of 45 mph (72.4 kph). To be considered a valid test, the vehicle speed was required to remain within ± 1.2 mph (± 2 kph) of the target speed, from the start of the test until any part of the vehicle, as defined by the two dimensional geometry described later in this paper, had crossed a lane line by at least 3.3 ft (1 m). Where possible, cruise control was used; otherwise, the driver modulated the throttle throughout the maneuver. For the BMW 528i and Buick Lucerne, the steering rate for each test was nominally 125 deg/s, and all steering inputs were commanded with a programmable steering machine. In the case of the Infiniti EX35, a skilled test driver manually performed the lane departures.As previously shown in Figure 1, the LDW straight road course was positioned on the VDA such that the test vehicle could easily reach the 45 mph (72.4 kph) target speed, while also providing approximately 1000 ft (300 m) of pavement over which the departure could take place. To maximize input repeatability, two pylon-delimited gates were used to help guide the driver to the appropriate course1, and all steering inputs were initiated from a common location. In the case of the tests performed with the BMW 528i and Buick Lucerne, repeatability was further enhanced by automatically initiating these inputs with the programmable steering machine, triggered as the vehicle was driven over a thin metal plate line lined with retro-reflective tape centered within the confines of the second gate. More detailed course specifications are provided in Figure 4. Note that Figure 4 illustrates the test scenario for a left departure. The vehicle was driven on the right side of the lane line to evaluate left-side lane departure warning performance, and on the left side of the lane line for the right-side lane departure tests.1 Use of additional gates would have been helpful, however researchers were concerned that visually, the extra pylons would define two distinct rows (i.e., on either side of the travel lane) that could be potentially interpreted as two lane lines by an LDW detection algorithm. If this occurred, it would confound the researchers’ ability to confirm whether a particular LDW system could be initialized from, and operated with, the presence of only one lane line.In the case of the BMW 528i and Buick Lucerne, thestraight road lane departure tests were performedusing steering angles from 1 to 15 degrees, input withan incremental increase of one degree per individualtrial. For the Infiniti EX35, the driver was instructedto perform lane departures using a range of steering angles and rates. The subsequent data wereprocessed, and the lateral position and velocity of thevehicle at the time of the LDW alert calculated. Insome cases, particularly during the left departureattempts, the combination of open-loop automationand a one-degree steering angle failed to produce alane departure before the end of the test course. Assuch, these data were treated as outliers and not usedfor subsequent analyses.TEST RESULTSThe test procedures described in this paper wereintended to provide NHTSA with the ability toobjectively evaluate contemporary LDW systems.To quantify performance, the lateral distance fromthe vehicle to the lane line, and the lateral velocity ofthe vehicle with respect to the lane line, at the time ofthe LDW alert were determined.To calculate the lateral distance from the vehicle tothe lane line during post processing of the data, eachtest vehicle was first represented by a twodimensional polygon whose length and width weredetermined by considering the outboard-most contactarea of the tires to the ground. Using thisrepresentation, the position of the vehicle (calculatedwith highly accurate differentially corrected GPSdata) was compared to the static lane line survey forthe straight course of interest. At the instant theLDW alert was initiated, the lateral distance from theclosest corner of the polygon to the lane line wasdetermined.The vehicle’s lateral velocity was calculated from the heading angle with respect to the lane line edge and forward velocity. At the onset of the LDW alert, trigonometric Equation 1 was solved [5]. V lat = V fwd * Sine Θ (1)where: V lat = Lateral velocity perpendicular to the vehicle with respect to the edge of the lane line.V fwd = Forward velocity of the vehicle. Θ = Angle between the vehicle heading and the edge of the lane line. An overall summary of the lateral positions and velocities observed at the time of the LDW alert during straight road departures over a solid white lane line are shown in Figures 5, 6, and 7. In each figure, right departures are shown in red, left departures in blue. BMW 528i For the BMW 528i, LDW alerts were presented during 28 of the 30 valid tests performed. For the two tests an alert was not observed (during one departure to the left, and during one to the right), the lateral velocities at the inboard edge of the lane line were 2.6 and 4.0 ft/s, respectively. Figure 5 presents the lateral positions and velocities observed at the time of the LDW alert during 28 straight road departures performed with the BMW 528i. Figure 5 reveals two interesting trends. First, as the lateral velocity of the approach became higher, the distance from the vehicle to the lane line at the time of the LDW alert increased. Second, tests performed with steering to the right always produced alertsearlier than those performed with steering to the left (i.e., for the same lateral velocity, the LDW alert occurred when the vehicle was further away from the lane line when a departure to the right was used). The data presented in Figure 5 imply the BMW 528i LDW algorithms consider lateral velocity when determining when the alert should be presented and not just the proximity of the vehicle to the lane line. Intuitively, this makes sense; as the lateral velocity of an unintended drift increases, the time the driver has before a lane departure occurs is reduced. Presenting alerts earlier in time would be expected to maximize the amount of time the driver has to take corrective action before the lane line is actually breached. Such findings have been documented in research performed in both simulators and on road studies [6,7]. It should also be noted that that careful attention must be made in how the alerts are presented so as to not annoy the driver [7,8,9].The specific reasons for the apparently asymmetrical alert observed during the BMW 528i evaluation are unknown. On one hand, the crash data do indicate that when a vehicle is involved in a “Road Edge Departure without Prior Vehicle Maneuver” scenario, the vehicle departs the road edge to the right in approximately two-thirds of the cases [3]. Overall, about 2.79 percent of all people involved in this crash scenario suffered high level Maximum Abbreviated Injury Scale (MAIS) 3+ injuries (serious, severe, critical, or fatal).However, while departing a lane to the right may ultimately evolve into a road departure, departures to the left may result in the driver’s vehicle encroaching into another vehicle traveling in the opposite direction. The resulting crashes are often quite serious. Although the frequency of the “Vehicle(s) Not Making a Maneuver – Vehicles Traveling in Opposite Direction” crash scenario is less than that of the “Road Edge Departure without Prior Vehicle Maneuver” crashes, about 2.58 percent of all people involved on this crash scenario suffered high level MAIS 3+ injuries [3].For these reasons, developing a more complete understanding of the tuning philosophy used for the vehicles like the BMW 528i LDW may be an interesting subject for future research.Buick LucerneIn the case of the Buick Lucerne, LDW alerts were presented during 24 of the 30 valid tests performed. When left lane departures were commanded, alerts were not produced during tests performed with lateral velocities of 3.8, 4.0, 4.4, and 4.7 ft/s. When right departures were used, alerts were not produced during tests performed with lateral velocities of 4.6, and 5.6 ft/s. Figure 6 presents the lateral positions and velocities observed at the time of the LDW alert during 24 straight road departures performed with the Buick Lucerne.For the Buick Lucerne LDW, each alert was observed during2 (i.e., when lateral displacements was ≤ 4 in) 2 A lane departure was taken to begin the instant the vehicle crossed the inboard edge of the lane line, and that the lane line was 4 in (10.2 cm ) wide.Figure 5. Lateral positions and velocitiesFigure 6. Lateral positions and velocitiesor after (i.e., when lateral displacements was > 4 in) the lane departures associated with the individual trials. Also, the distance from the vehicle to the lane line generally decreased as the lateral velocity of the approach became higher. The reason for this trend is unclear, but the vehicle’s LDW sampling rate, processing speed, and/or alert response time are suspect. For example, as the lateral velocity toward the lane line increases, the amount of time available to establish and report an imminent departure is reduced. If the sample rate is not sufficiently high, the lateral distance traveled between the data points used to predict the likelihood of a departure will increase.In the case of the Buick Lucerne, the alerts observed during right departures generally occurred sooner than those associated with left departures for a common lateral velocity. However, the effect was subtle; much less apparent than seen during theBMW 528i evaluation.Infiniti EX35The tests performed with the Infiniti EX35 indicate LDW evaluations can be successfully executed with a skilled test driver in lieu of a programmable steering machine. However, due to the manner in which the driver input the steering, the number of Infiniti EX35 tests performed with high lateral velocities was more limited than those used to assess the LDW performance of the other vehicles. Figure 7 presents the lateral positions and velocities observed at the time of the LDW alert during 59 straight road departures performed with the Infiniti EX35. LDW alerts were observed during all valid tests.Despite the limited range of lateral velocities produced by the driver-based lane departures performed with the Infiniti EX35, the authors believe the data produced by these tests were capable of revealing some meaningful trends about the vehicle’s LDW operation.First, although some data outliers were produced, the distance from the vehicle to the lane line remained quite consistent across the limited range of lateral velocities considered. Second, the data shown in Figure 7 indicate the Infiniti EX35 LDW alerts are not asymmetric. For this vehicle, alerts observed during the right departures occurred with nearly equivalent combinations of lateral displacement and lateral velocity as those associated with departures to the left (discounting the outlying data points). CONCLUSIONLane Departure Warning (LDW) system functionality is of great interest to NHTSA. Given the prevalence of unintended road departures in the crash data, and the high societal costs they impose, better understanding how advanced technologies may be able to assist drivers in mitigating these crashes is an agency priority. This paper has provided details of how NHTSA evaluated the LDW performance of three contemporary passenger cars using a test scenario designed to emulate one of the most commonly occurring pre-crash road departures scenarios. LDW performance was evaluated by considering the vehicle’s proximity and approach rate to the inboard edge of a single lane line at the time of the LDW alert.The LDW systems installed in the vehicles discussed in this paper each had unique performance characteristics. Specifically, variations in how the alerts were presented to the driver, and the manner in which the timing of the alerts changed as a function of the lateral velocity toward the lane line, were observed. How these factors affect the ability of the systems to mitigate unintended lane departures in the real-world will be addressed in future research activities.Figure 7. Lateral positions and velocities observed at the time of the LDW alert during lane departures performed with the Infiniti EX35.REFERENCES1.National Center for Statistics and Analysis,“Traffic Safety Facts 2007, Early Edition,” U.S.Department of Transportation, National Highway Traffic Safety Administration.2.Wang, J., Knipling, R. R., “Single VehicleRoadway Departure Crashes: Problem SizeAssessment and Statistical Description,” DOTHS 808 113, March 1994.3.Najm, W.G., Stearns, M.D., and Yanagisawa,M., “Pre-Crash Scenario Typology for CrashAvoidance Research,” DOT HS 810 767, April2007.4.Federal Highway Administration, “Manual onUniform Traffic Control Devices,”/index.htm.5.Burgett, A., Ranganathan, R., Srinivasan, G.,“Development Of Objective Tests ForEvaluation Lane-Keeping / Road DepartureDriver Assistance Systems,” Proceedings fromESV 2007, Paper Number 07-0155. 6.Pomerleau, D., Jochem, T., Thorpe, C., Batavia,P., Pape, D., Hadden, J., McMillian, N., Brown,N., Everson, J., “Run-Off-Road Collision Avoidance Using IVHS Countermeasures,”DOTHS 809 170, December 1999.7.Tijerina, L., Jackson, J.L., Pomerleau, D.A.,Romano, R.A., Perterson, A. “Run-Off-Road Collision Avoidance Countermeasures Using IVHS Countermeasures TASK 3-Volume 2,”DOT HS 808 502, August 1995.8.LeBlanc, D., Sayer, J., Winkler, C., Ervin, R.,Bogard, S., Devonshire, J. Mefford, M., Hagan,M., Bareket, Z., Goodsell, R., and Gordon, T.“Road Departure Crash Warning System FieldOperational Test: Methodology and Results,”UMTRI 2006-9-1, June 2006.9.Ho, A., Cummings, M.L., Wang, Enlie, Tijerina,L., Kochhar, D.S. “Integrating Intelligent DriverWarning Systems: Effects of Multiple Alarmsand Distraction on Driver Performance,”Compendium of Papers CD-ROM of the 85thAnnual Meeting of the Transportation ResearchBoard, Washington, D.C., January, 2006.APPENDIXTable A1.Instrumentation Used During LDW EvaluationType Output Range Resolution AccuracyVehicle speed 0.3 - 77 mph*(0.5 - 125 kph)0.001 mph*(0.01 kph)0.06 mph*(0.1 kph)Longitudinal position with respect to the lane line N/A2 in(5 cm)< 3.9 in (10 cm) absolute;1.6 in (1 cm) staticLateral position with respect to the lane line N/A2 in(5 cm)< 3.9 in (10 cm) absolute;1.6 in (1 cm) staticDifferentially- corrected GPS dataLateral velocity with respect to the lane line N/A0.33 ft/s(0.1 m/s)±0.33 ft/s(±0.1 m/s)Data Flag (Test Course Gate)Signal to initiate automated steeringinputs when driven over a retro-reflective marker0 – 10V N/AOutput response better than10 msData Flag (LDW Alert) Signal indicating the LDW alert status ±10V N/AOutput response better than10 msVehicle Dimensional Measurements Location of GPS antenna, vehiclecenterlines, and two bumpermeasurementsN/A0.05 in(1mm)0.05 in(1mm)*Values for the stand alone vehicle speed sensor used to provide output to the dashboard display and for data synchronization.。

金衬底调控单层二硫化钼电子性能的第一性原理研究

1.1
模型与计算方法
几何结构优化和电子结构的计算采用基于密
度泛函理论平面波赝势方法的 VASP (Vienna abinitio simulation package) 软件包完成 [23] . 原子实和价电子之间的相互作用通过缀加投影波方法 (projector-augmented wave method PAW) 赝势来描述. 平面波截断能量为 400 eV. 电子间相互作用的交换关联能采用广义梯度近似的 Perdew-BurkeErnzerhof [24] 方案处理. 布里渊区积分计算 K 点网格采用 Monkhost-Pack [25] 方法产生, 结构优化计算采用 9 × 9 × 1, 能带计算和态密度计算采用 19 × 19 × 1, 且都考虑自旋轨道耦合作用. 在优化单层二硫化钼过程中, 对所有原子进行完全弛豫, 单个原子能量收敛精度为 10 小于 0.01 eV/ Å. 金衬底吸附单层二硫化钼结构中, 选取金 (111) 面作为衬底金, 原子层由下至上依次标记为 A, B, C, A, B, 如图 1 (b) 所示. 单层二硫化钼 (0001) 面下层硫原子与金原子 B 层结合, 硫原子分别可以采取 A, B, C 三种排布方式通过比较结合能大小的方式确定硫原子层的最优排布. 理论计算中, 选取 1 × 1 × 8 共 8 个原子的原胞, 如图 1 (a) 中红色菱形所示. 其中自底向上的 A, B, C 三层
. 与石墨烯转化为扶手纳米条带时迁
[20]
移率下降几个数量级相比, 二硫化钼扶手形纳米条带迁移率数值保持不变, 极性发生转换 . 有V形
[21]
缺陷的锯齿形纳米条带表现出半导体性质属, 可用于电极和传输线

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PACKER ENGINEERING INC,1950 North Washington Street,Naperville, IL 60566Metallurgical Evaluation of a DOT-3AA Cylinder,Serial No. 441106, with Pin Hole LeakFINAL REPORTJune 2007Prepared forMark ToughiryOffice of Hazardous Materials TechnologyPipeline and HazardousMaterials Safety AdministrationU.S. Department of TransportationPurchase Order No. DTPH56-07-P-000007This document was prepared under the sponsorship of the U.S. Department of Transportation. Neither the United States Government nor any Person Acting on behalf of the United States Government assumes the responsibility resulting from the use or publication of information contained in this document or warrants that such use of publication of the information contained in this document will be free from privately owned rights.Table of Contents1.0 Introduction (3)1.1 Technical Approach (3)2.0General Documentation of the Cylinder (4)2.1Visual Documentation and Cylinder Specifications (4)2.2Non Destructive Evaluation (4)3.0Metallurgical Analysis (5)3.1Visual Observation and Sectioning of Cylinder (5)3.2Chemical Analysis of the Cylinder (5)3.3Fractography and Metallography (6)4.0Mechanical Property Evaluation (7)4.1Tensile Test (7)4.2Rockwell Hardness Test (8)4.3Microhardness Evaluation (9)5.0Discussion (10)6.0Conclusion (11)7.0Figures (12)8.0 References (31)1.0 INTRODUCTIONObjective: - The purpose of this project is to determine chemical and metallurgical characteristics of the cylinder with a leak, initial point of fracture and possible cause of leak.Approach1.1 TechnicalIn this project the DOT – 3AA cylinder with serial number 441106 was analyzed to determine the chemical and metallurgical characteristics of the leak.The general condition of the cylinder was documented. The location of the leak was identified and documented. Radiography was performed on the cylinder to characterize and confirm the location of the leak. Ultrasonic inspection was performed to characterize the length of the crack and thickness of the cylinder near the crack. After performing the non-destructive testing, the cylinder was cut open. The inside surface of the cylinder was documented. Chemical analysis was performed on a sample removed from the cylinder. Magnetic particle testing was performed on the identified leak location to confirm the size of the crack. The cylinder was cut open to perform fractographic analysis on the leak surface. The fracture surface was documented using a stereomicroscope, before cleaning the oxide scale. An Energy Dispersive Spectroscopy (EDS) analysis was performed on the uncleaned fracture surface. The fracture surface was cleaned using ultrasonic cleaning and replica strip cleaning technique. The cleaned fracture surface was analyzed using the scanning electron microscope. After completing the fractographic analysis the sample was cut perpendicular to the fracture surface and the microstructure was analyzed and compared to the microstructure of the sample cut in the same grain direction but away from the fracture surface. Microhardness was measured on both samples. Rockwell hardness was measured along the length of the largest piece of the cylinder using ASTM E-18-98. A tensile test was performed to measure the strength and ductility of the ruptured cylinder in accordance with 49 CFR 178.37- K and L.2.0 GENERAL DOCUMENTATION OF THE CYLINDER2.1 Visual Documentation and Cylinder SpecificationsThe cylinder was identified as a DOT - 3AA cylinder with serial number 441106 as shown in Figure 1. The indented markings on the cylinder are as shown in Figure 2.•The cylinder is marked as DOT – XXXXXXX GL Limited 441106. 119501 6A 06 TP377 5PSI 11566 VA3.3.•As per the information provided to Packer Engineering Inc by DOT, the service pressure of the cylinder is 2,265 psi. The minimum design wallthickness is 0.228 inch.•The maximum diameter of the cylinder is 9 inches as measured by Packer Engineering Inc.•The surface of the cylinder appears to be sandblasted.• A surface flaw was observed in the transverse direction of the cylinder as shown in Figure 3. It is located 16.5 inches from the bottom of the cylinder. Ahigher magnification image of the surface flaw is as shown in Figure 4.2.2Non Destructive EvaluationX-ray radiography was performed on the cylinder to characterize the surface flaw on the cylinder. The cylinder was radiographed in two different orientations. The first orientation consisted of a longitudinal view of the cylinder with the source perpendicular to the outer surface at the flaw location. The radiograph in Figure 5 indicates that it is not simply a surface flaw, but that the flaw penetrates a significant portion of the cylinder wall. The second orientation was in the transverse direction with the source at a 45 degree angle to the defect. The radiograph in Figure 6 also shows the defect and confirms that it is not just a surface flaw.Pressure testing was performed on the cylinder using air to confirm the presence of the leak. The cylinder was connected to a portable air compressor with a test gauge and regulator in-line between the compressor and the cylinder. Gas Leak Detector (soap solution) was applied on the cylinder surface and pressure was slowly applied. At approximately 5 psi, bubbles were visible from the area of the surface flaw. The test was continued up to approximately 20 psi, at which air could be felt escaping through the flaw. No other leak was detected in the cylinder. This test was repeated two times to confirm the findings.Ultrasonic inspection was performed to analyze the leak and thickness variation of the cylinder along the length. Figure 7 shows the ultrasonic testing of the cylinder. The shear wave analysis at the leak using 5mHz, 45º shoe, ½” diameter from 180 º back indicates the depth of the crack is 0.158 inch as indicated by Figure 8. The maximum depth of the crack is 0.174 inch as shown in Figure 9. The maximum length of the crack determined by ultrasonic inspection was 0.63 inch. The thickness of the cylinder was analyzed usingshear wave around the circumference of the cylinder containing the crack. Table I lists the thickness measurements along the cylinder length in the plane that contains the leak. The wall thickness 3 inches above the bottom of the cylinder is 0.242 inch. The wall thickness near the crack is 0.244 inch. These thickness measurements indicate that the wall thickness of the subject cylinder meets the 0.228 inch minimum design requirement.TABLE IThickness measurement along the length of the cylinder# Distance of the cylinder from bottom (inch) Thickness along the length of cylinder and in the plane containing leak (inch)1 3 0.2422 12 0.2433 16 0.2444 24 0.2465 36 0.2536 46 0.2553. METALLURGICAL ANALYSIS3.1 Visual Observation and Sectioning of the CylinderFigure 10 shows the location at which the cylinder was sectioned. Figure 11 indicates the presence of corrosion products on the inside wall of the cylinder. The inside surface at the leak is as shown in Figure 12. The samples for tensile testing and chemical analysis were sectioned from the area marked in Figure 13 and Figure 14. The arrows shown in the Figure 13 and Figure 14 indicate the leak location. The cylinder was sectioned as shown in Figure 15 to cut open the leak. Fractography and metallograhy were performed on one surface of the leak and the other side of the leak was retained.3.2 Chemical Analysis of the CylinderThe chemical analysis of the subject DOT-3AA cylinder with serial number 441106 was compared to the steel materials authorized for DOT-3AA cylinders by the Code of Federal Regulations (CFR) 49, Chapter I – Research and Special Programs Administration, Department of Transportation, Subchapter C- Hazardous Material Regulations, part § 178.37. The comparison is as shown in Table II. The composition of the subject DOT-3AA cylinder meets the specifications for 4130X steel.TABLE IIComparison of the chemistry of the subject DOT cylinder with steel authorized forDOT-3AA cylinder as per 49 CFR part § 178.37Designation ElementsSubjectDOTcylinder(%) 4130X (%) NE8630 (%) 9115 (%) 9125 (%) Carbon-Boron (%) Intermediate Manganese (%)Carbon0.31 0.25/0.35 0.28/0.33 0.10/0.20 0.20/0.30 0.25- 0.37 0.40 max Manganese0.58 0.40/0.90 0.70/0.90 0.50/0.75 0.50/0.75 0.80-1.40 1.35/1.65 Phosphorus0.011 0.04 max 0.04 max 0.04 max 0.04 max 0.035 max 0.04 max Sulfur0.008 0.05 max 0.04 max 0.04 max 0.04 max 0.045 max 0.05 max Silicon0.27 0.15/0.35 0.20/0.35 0.60/0.90 0.60/0.90 0.3 max 0.10/0.30 Chromium0.84 0.80/1.10 0.40/0.60 0.50/0.65 0.50/0.65 - - Molybdenum0.17 0.15/0.25 0.15/0.25 - - - - Zirconium- - - 0.05/0.15 0.05/0.15 - - Nickel0.02 - 0.40/0.70 - - - - Boron- - - - - 0.005/0.003 - Copper0.03 - - - - - - Aluminum0.04 - - - - - -3.3 Fractography and MetallographyThe cut section of the cylinder was observed under stereomicroscope at up to 60 X magnification. Figures 16 -18 show the stereoscope images of the section containing fracture. The surface of the as-received fracture appears to be corroded as indicated in Figure 18. The EDS analysis of the as-received fracture surface is shown in Figure 19. It indicates presence of iron (Fe), chromium (Cr), silicon (Si), carbon (C) oxygen (O), sulfur (S), silicon (Si), aluminum (Al), copper (Cu), chlorine (Cl), nickel (Ni) and sodium (Na). The fracture surface was then cleaned using replica strip cleaning, ultrasonic cleaning and rinsing with acetone. Even after cleaning several times, the fracture surface had an adherent oxide layer. The cleaned fracture surface was observed using scanning electron microscopy (SEM). Figures 20-22 show the fracture surface at the ID, center and OD of the cylinder wall respectively. As seen in the figures, the details of the fracture are obscured by oxides.In order to perform metallographic analysis, the section containing fracture surface (Sample A) was cut perpendicular to the fracture and compared to the microstructure of the sample cut in the same grain direction but away from the fracture surface (Sample B). The metallurgical mounts were prepared by polishing and etching with 2% Nital solution.Sample A (containing fracture surface):The micrographs across the fracture surface can be seen in Figures 23 to 29. Figure 24 indicates presence of oxide layer on the fracture surface and also indicates presence of copper-colored phase. Figure 30 shows that the overall microstructure across the cylinder wall is tempered martensite. However, the microstructure at the periphery of both OD and ID of the cylinder wall indicates decarburization in some areas as seen in Figures 31 and 32 respectively. Two crack-like areas can be seen at the OD of the cylinder wall as shown in Figure 31. They are non-propagating and not related to the fracture of the cylinder.Sample B (away from fracture surface):The overall microstructure of the sample taken away from fracture surface is also tempered martensite as shown in Figure 33. Also there was decarburization observed at the ID of the sample as shown in Figure 34.An EDS analysis was performed to evaluate the composition of the copper-colored phase and the dark and light gray oxide layer. Three areas at the fracture surface were analyzed as shown in Figure 35. The EDS at Location 1 and 2 and 3 are shown in Figure 36, 37 and 38, respectively. EDS at Location 1 indicates presence of copper (Cu), aluminum (Al), tin (Sn) and iron (Fe). The EDS at Location 2 (dark gray) shows presence of iron (Fe), chromium (Cr), silicon (Si), sulfur (S), chlorine (Cl), copper (Cu) and oxygen (O). The EDS at Location 3 (light gray) indicates that iron (Fe), manganese (Mn) and oxygen (O) are present.4 MECHANICAL PROPERTY EVALUATION4.1Tensile TestTensile sample was obtained from the location as shown in Figure 13. The testing was performed in accordance with 49 CFR 178.37-K and L. The results are as shown in Table III. The tensile properties of the subject DOT-3AA cylinder were compared to the mechanical properties of 4130 steel at tempering temperatures of 1000 ºF and 1200 ºF [2]. Part 178.37 of 49 CFR (g) (4) indicates that the minimum tempering temperature may not be less than 1000 ºF. Hence, the tensile test results were compared to only the values listed at 1000 ºF and above. As seen in the table, the tensile properties of the subject DOT-3AA meet the specifications as notes above.TABLE IIITensile test results of DOT-3AA cylinder compared to the tensileproperties of 4130 steelProperty DOT-3AAcylinder4130 Steel(Tempered at 1000 ºF)[ref 2]4130 Steel(Tempered at 1200 ºF)[ref 2]Tensile Strength 125 ksi 150 ksi 118 ksiYield Strength(0.2% offset)110 ksi 132 ksi 102 ksi% Elongation in2 inches20% 17% 22%4.2 Rockwell Hardness TestThe Rockwell Hardness Test was performed along the largest piece of the cylinder in accordance with ASTM E18-98. The hardness tester was calibrated using a Patriot Manufacturing Company standard block with serial number 00B5167 and standard hardness value of 32.3 +/- 1.0 HRC. The hardness measured using the standard block was33.2 at the beginning of the test and 32.0 at the end of the test. The results are as shownin Table IV. The hardness values of 4130 steel at tempering temperatures of 1000 ºF and1200 ºF are 34 HRC and 24 HRC respectively [2]. The hardness of the DOT-3AA cylinder indicates that it was tempered above 1000 ºF.Table IVRockwell hardness results of the DOT-3AA cylinder compared to the hardnessvalues of 4130 steelLocation DOT-3AAcylinder(HRC)4130 Steel(Tempered at 1000 ºF)(HRC)[ref 2]4130 Steel(Tempered at 1200 ºF)(HRC) [ref 2]1 282 273 264 275 276 2634 244.3 Microhardness EvaluationThe microhardness was evaluated for the metallurgical mounts prepared across the fracture surface and away from the fracture using ASTM E92 - 03. The results are indicated in Table V and Table VI. The average hardness at about the center of the cylinder wall thickness is similar for both samples. However, the average hardness at the OD and ID is closer to the fracture surface, which is most likely due to decarburization.TABLE VHardness measurements close to the fracture surface# Distance From OD (inches) Hardness (HRC) Average (HRC)1 0.007 (Close to OD) 22212 0.014 (Close to OD) 213 0.021 (Close to OD) 21(center) 264 0.11225(center) 255 0.119(center) 246 0.1267 0.217 (Close to ID) 198 0.224 (Close to ID) 22219 0.231 (Close to ID) 22TABLE VIHardness measurements away from fracture surface# Distance From OD (inches) Hardness (HRC) Average (HRC)1 0.007 (Close to OD) 26262 0.014 (Close to OD) 263 0.021 (Close to OD) 27(center) 254 0.11226(center) 265 0.1196 0.126(center) 277 0.217 (Close to ID) 22258 0.224 (Close to ID) 269 0.231 (Close to ID) 275 DISCUSSIONMetallurgical evaluation was performed on the DOT - 3AA cylinder with serial number 441106 to identify the cause and origin of the leak. The leak was located 16.5 inches from the bottom of the cylinder. The presence of a leak was confirmed using non-destructive techniques such as radiography, pressure testing and ultrasonic testing. The leak was oriented in the transverse direction. Hence, hoop stresses created by internal gas pressure cannot be responsible for the rupture.The composition of the DOT - 3AA cylinder meets the specifications for 4130X steel as given in 49 CFR, part § 178.37. The tensile strength, yield strength, elongation and hardness of the DOT - 3AA cylinder indicate it was tempered above 1000o F as required in 49 CFR, part § 178.37 (g) – 4.Metallography and EDS of the fracture surface showed that a copper-rich phase containing a small amount of tin is present along the grain boundaries near the fracture and in the oxide on the fracture surface. The copper-tin phase most likely represents the remnants of a bronze-type material that came into contact with the cylinder while the cylinder was near its hot deformation temperature. The bronze material melted and was included into the steel. Based on the presence of copper and tin, and the apparent lack of elements such as zinc, aluminum, nickel and lead, it may be speculated that a phosphor bronze material contacted the cylinder. However, the precise identification of the copper-bearing material is not significant for determination of the process by which the leak formed in the subject cylinder.If the bronze material entered the molten 4130X alloy, the bronze would likely have dissolved and become distributed throughout the billet. However, the nominal copper content of the cylinder was determined to be 0.03%. Bulk copper concentration at 0.03% would not be considered to be elevated, or high enough to cause cracking. Finally, copper-rich phases in grain boundaries were not seen in the microstructure away from the fracture. Therefore, the bronze material most probably did not enter the molten steel alloy.The recommended temperatures for hot deformation processes such as forging or extrusion generally range from 1600o F to 2245o F for 4130 [3]. The liquidus temperature for phosphor bronze alloys generally ranges from 1800-1920o F (The liquidus for pure copper is 1950o F.) [4]. Note that the recommended austenitizing temperature for 4130 is 1600o F which would be too low to melt bronze or pure copper. Therefore, the inclusion of the copper alloy into the cylinder must have occurred during hot deformation. Based on the observation that the crack was wider at the OD of the wall compared with the ID, it is likely that the crack was initiated by inclusion of copper at the OD and propagated toward the ID.The thick oxide layers on the fracture surface of the leak indicate the crack was open during hot deformation and subsequent heat treatment. The presence of copper phases inthe oxide layers indicates the bronze component was molten as the oxide films were forming during hot deformation.Cracking of steel resulting from contact with molten bronze has been reported in locomotive axles when bearing failure resulted in frictional heating of bronze bearing components to the point where molten bronze contacted the steel axle. This phenomenon has been characterized as liquid metal embrittlement. Three factors are generally required for embrittlement of steel by copper: (1) applied tensile stress, (2) wetting of the steel by molten copper, and (3) heating the steel into the austenite range [5]. In the caseof the DOT cylinder, tensile stress would have been created during hot deformation. Note that the transverse orientation of the leak would be consistent with the direction of tensile stresses created during deformation to form the cylinder. Also, the requirement that a tensile stress be present suggests that the bronze came into contact with the billet prior to forging rather than after forging was complete and stresses were thermally relieved. Wetting by copper would have occurred when the bronze material contacted the steel at forging temperature and the steel would have been in the austenite range at forging temperature. Therefore, the commonly recognized requirements for liquid metal embrittlement were present when the DOT – 3AA cylinder was formed.6 CONCLUSIONSThe leak on the DOT – 3AA cylinder was caused by liquid metal embrittlement. A localized area of the cylinder was liquid metal embrittled by contact with a copper-rich material, probably a phosphor bronze, while the cylinder was at forging temperature.This concludes the metallurgical evaluation of a DOT-3AA cylinder with serial no. 441106 with pin hole leak. If you have questions or need additional information please email us at mpareek@ or call at 630-577-1930.Sincerely,PACKER ENGINEERING, INC.____________________________ ____________________________Mridula L Pareek Craig L. Jensen, Ph.D., P.E.Materials Engineering, Director EngineeringTechnologist7FIGURESFigure 1: DOT-3AA cylinder as receivedFigure 2: Indented marking on the DOT-3AA cylinderSurface flawFigure 3: Surface flaw in the transverse direction on the DOT-3AA cylinderFigure 5: Radiograph of DOT cylinder with the X-ray source perpendicular to theflaw. The arrow is pointing to the defect.Figure 6: Radiograph of DOT cylinder with X-ray source at 45 º to the flaw. Thearrow is pointing to the defect.Figure 7: Ultrasonic testing of the DOT-3AA cylinderwave analysisFigure 9: Ultrasonic Testing - maximum depth of crack measured using shear waveanalysisFigure 10: Showing location of sectioning of the DOT-3AA cylinderFigure 11: Shows corrosion on the inside wall of the cylinderFigure 12: Shows the inside surface of the leakFigure 13: Shows location at with the samples for tensile testing and chemistryanalysis were sectionedFigure 14: Shows sections cut for tensile testing and chemistry analysis.Leak LocationTensileSample Chemistry SampleLeak LocationTensileSample Chemistry SampleFigure 15: Sectioning of the cylinder to cut open the leakFracture SurfaceFigure 16: Seteroscope image of the outer surface of the cylinder section containingthe fracture surface. Magnification 65XFigure 17: Stereoscope image of the inner surface of the cylinder section containingthe fracture surface. Magnification 65XFigure 18: Stereoscope image of the cylinder section showing the fracture surface. Magnification 65XFracture SurfaceFracture surfaceFigure 19: EDS of the non-cleaned fracture surface of the cylindercylinder wall. Magnification 75X.Figure 21: SEM image at the center of the fracture surface. Magnification 75XFigure 22: SEM image of the fracture surface close to the outer diameter of thecylinder wall. Magnification 75 XFigure 23: Microstructure across the fracture surface at the outer diameter of the cylinder. Magnification 200X. Etchant: 2% NitalFigure 24: Microstructure across the fracture surface showing tempered martensite structure, presence of corrosion products (gray) and copper colored phase (orange) in continuation with Figure 23. Magnification 200X. Etchant: 2% NitalFigure 25: Microstructure across the fracture surface showing copper colored phase in the tempered martensite structure in continuation with Figure 24. Magnification200X. Etchant: 2% NitalFigure 26: Microstructure across the fracture surface in continuation with Figure25. Magnification 200X. Etchant: 2% NitalFigure 27: Microstructure across the fracture surface in continuation with Figure26. Magnification 200X. Etchant: 2% NitalFigure 28: Microstructure across the fracture surface in continuation with Figure26. Magnification 200X. Etchant: 2% NitalFigure 29: Microstructure across the fracture surface at the ID in continuation with Figure 28. Magnification 200X. Etchant: 2% NitalFigure 30: Tempered martensite structure observed in the sample containing fracture surface. Magnification 200X. Etchant: 2% NitalFigure 31: Shows decarburization at the OD of the cylinder in the sample containing fracture surface. Two crack like areas can be seen in thedecarburized region. Magnification 200X. Etchant: 2% NitalFigure 32: Shows decarburization at the ID of the cylinder in the sample containing fracture surface. Magnification 200X. Etchant: 2% NitalFigure 33: Tempered martensite structure observed in the sample taken away from the fracture surface. Magnification 200X. Etchant: 2% NitalFigure 34: Shows decarburization at the ID of the sample taken away from the fracture surface. Magnification 200X. Etchant: 2% NitalFigure 35: Shows the locations near the fracture surface at which EDS analysis wasperformed. Magnification 350X.Figure 36: EDS analysis near the fracture surface at Location 1 identified inFigure 35123Figure 37: EDS analysis near the fracture surface at Location 2 identified inFigure 35Figure 38: EDS analysis near the fracture surface at location 3 identified inFigure 358.0REFERENCES1.Code of Federal Regulations (CFR) 49, Chapter I – Research and SpecialPrograms Administration, Department of Transportation, Subchapter C- Hazardous Material Regulations, part § 178.37, pg 729 – 733, 2002.2.ASM Metals Reference Book, 3rd edition, pg 309, 1993.3.Heat Treater’s Guide Practices and Procedures for Irons and Steels, 2nd edition,Harry Chandler, pg 300, 1995.4.Metals Handbook, 8th edition, Vol 1, Properties and selection of metals, pg 1027,1972.5.Metals handbook, 9th edition, Vol 11, Failure Analysis and Preventions, pg 715 to727, 1986.31。