酞菁染料与氯离子协同效应在酸性镀铜中的作用

采用旋转圆盘电极和交流阻抗方法研究酞菁染料（PC）及其与氯离子协同效应对酸性镀铜电沉积过程的影响，通过选择不同浓度的酞菁染料，研究它们在不同转速下的阴极极化行为和交流阻抗图谱，对其在电极表面的成膜状态作了深入研究。极化的电位从自然电位到－0．6V（相对SCUE）。结果表明，PC在酸铜电镀中所起的作用更多依赖于其在表面形成吸附膜的结构，而非单纯的电荷吸引。     

纳米单晶铜磨料磨损行为的分子动力学研究

目的探究在不同参数下纳米单晶铜的磨料磨损行为。方法通过构建纳米单晶铜的摩擦磨损模型,对磨粒施加不同的滑动速度、滑动距离以及外载荷,研究在不同滑动速度、滑动距离、外载荷下纳米单晶铜磨料磨损行为。结果随着磨料与单晶铜基体之间滑动速度的增加(50, 100, 200 m/s),基体内部缺陷减少;随着滑动距离的增大(4, 8, 16 nm),基体被去除的原子增多且主要集中在磨料前端;随着外载荷的增大(40,80 nN),基体内部缺陷的最大深度增大,且表面无定形原子增多。结论在不同的滑动速度、滑动距离、外载荷等参数下,主要包括基体内部缺陷和表层无定形原子的纳米单晶铜磨料磨损行为有明显差异。     

Guided Molecular Assembly on a Locally Reactive 2D Material

Atomically precise engineering of the position of molecular adsorbates on surfaces of 2D materials is key to their development in applications ranging from catalysis to single‐molecule spintronics. Here, stable room‐temperature templating of individual molecules with localized electronic states on the surface of a locally reactive 2D material, silicene grown on ZrB₂, is demonstrated. Using a combination of scanning tunneling microscopy and density functional theory, it is shown that the binding of iron phthalocyanine (FePc) molecules is mediated via the strong chemisorption of the central Fe atom to the sp³‐like dangling bond of Si atoms in the linear silicene domain boundaries. Since the planar Pc ligand couples to the Fe atom mostly through the in‐plane d orbitals, localized electronic states resembling those of the free molecule can be resolved. Furthermore, rotation of the molecule is restrained because of charge rearrangement induced by the bonding. These results highlight how nanoscale changes can induce reactivity in 2D materials, which can provide unique surface interactions for enabling novel forms of guided molecular assembly.     

微纳米尺度单晶铜各向异性表面切削特性实验研究

利用纳米压痕仪和原子力显微镜对微纳米尺度下单晶铜各向异性表面在不同载荷和刻划速度下的切削特性进行实验研究。结果表明:单晶铜各晶面表面在较低载荷下,划痕细小且不明显。随着载荷的逐渐增大,划痕深度和宽度逐渐变大,并形成明显的沟槽,在沟槽的两侧出现明显的侧流现象,探针前方出现切屑堆积,尤其单晶铜Cu(100)切屑堆积较明显;单晶铜Cu(100)在刻划速度为10μm/s、50μm/s时,切削力无明显变化规律,其余两晶向都是在同等载荷下,刻划速度越大,切削力越大。随着刻划速度的增大,切削力趋于稳定;载荷越大,切削力越大,其相应摩擦系数也增大。     

新型折叠夹芯结构材料研究进展

折叠夹芯结构是一种具有轻质、高比强、高比刚度以及多功能潜力的新型三维结构材料,近几年受到国内外学者的极大关注.它将成为新一代结构功能一体化的理想结构材料.主要概述了折叠夹芯结构的发展历程,包括折叠芯材的拓扑构型设计、制备工艺研究以及折叠夹芯结构力学性能、失效方式、数值模拟和隔音、热力学等方面的工作.同时结合折叠夹芯结构的性能和优势,对其可能应用的领域进行预测,并对其未来研究方向进行了展望.     

聚乙烯亚胺添加剂对碱性镀铜电沉积行为的影响

为了研究碱性镀铜中添加剂对铜电沉积行为的影响,采用一种新型柠檬酸碱性镀铜工艺制备了铜镀层,研究了聚乙烯亚胺添加剂在新型柠檬酸盐碱性镀铜中的作用机理.运用SEM,XRD和电化学方法对镀液、镀层进行了分析.结果表明:聚乙烯亚胺有利于获得较宽的电流密度范围和均匀细致的镀层,使铜镀层表现出(111)晶面的择优取向,铜的沉积为侧向生长;聚乙烯亚胺优先吸附在阴极高电流密度处,并对铜沉积产生较强的阻化作用;铜电沉积的初期行为服从扩散控制和三维连续成核方式生长规律.     

舰船用高阻尼铜合金板材的研制

本文介绍了高阻尼铜合金板材用于舰船后传动系统的研制过程,并对影响阻尼特性的关键热处理工艺对其组织性能的影响进行了试验研究。试验表明,材料在820～850℃淬火和420℃×12h时效后,组织显示为清晰、整齐的孪晶马氏体组织,这些孪晶界面在交变应力的作用下,可以移动或滑移,从而吸收振动能量,达到减振降噪的功能。     

凝固方向对单晶高温合金枝晶组织的影响

用籽晶法制备了沿不同晶体取向凝同的镍基单晶高温合金试样,研究了单晶中枝晶形貌和一次枝晶臂距随凝固取向的变化规律.结果表明:凝同方向偏离[001]取向小于15°时,枝晶排列比较规则,一次枝晶臂距随偏离角度增大而减小;偏离角度为25°时,部分二次枝晶臂阻断了相邻一次枝晶干的生长,导致一次枝晶臂距增大.沿[011]和[111...     

表面处理对第二代单晶高温合金胞状再结晶的影响

对第二代镍基单晶高温合金进行表面处理并在1000～1200℃保温,研究表面加工工艺和热处理条件对胞状再结晶行为的影响.结果表明:磨削、吹砂、喷丸试样热处理后表面均发生了胞状再结晶,其生成厚度依次增加.喷丸试样经1200℃/50h后胞状再结晶区厚度可达0.1mm,晶团之间及与基体之间存在取向差小于5°的小角晶界和35～4...     

Adlayer‐Free Large‐Area Single Crystal Graphene Grown on a Cu(111) Foil

To date, thousands of publications have reported chemical vapor deposition growth of “single layer” graphene, but none of them has described truly single layer graphene over large area because a fraction of the area has adlayers. It is found that the amount of subsurface carbon (leading to additional nuclei) in Cu foils directly correlates with the extent of adlayer growth. Annealing in hydrogen gas atmosphere depletes the subsurface carbon in the Cu foil. Adlayer‐free single crystal and polycrystalline single layer graphene films are grown on Cu(111) and polycrystalline Cu foils containing no subsurface carbon, respectively. This single crystal graphene contains parallel, centimeter‐long ≈100 nm wide “folds,” separated by 20 to 50 µm, while folds (and wrinkles) are distributed quasi‐randomly in the polycrystalline graphene film. High‐performance field‐effect transistors are readily fabricated in the large regions between adjacent parallel folds in the adlayer‐free single crystal graphene film.     

A Highly Reliable Molybdenum Disulfide-Based Synaptic Memristor Using a Copper Migration-Controlled Structure

Memristors are drawing attention as neuromorphic hardware components because of their non-volatility and analog programmability. In particular, electrochemical metallization (ECM) memristors are extensively researched because of their linear conductance controllability. Two-dimensional materials as switching medium of ECM memristors give advantages of fast speed, low power consumption, and high switching uniformity. However, the multistate retention in the switching conductance range for the long-term reliable neuromorphic system has not been achieved using two-dimensional materials-based ECM memristors. In this study, the copper migration-controlled ECM memristor showing excellent multistate retention characteristics in the switching conductance range using molybdenum disulfide (MoS₂) and aluminum oxide (Al₂O₃) is proposed. The fabricated device exhibits gradual resistive switching with low switching voltage (<0.5 V), uniform switching (σ/µ ∼ 0.07), and a wide switching range (>12). Importantly, excellent reliabilities with robustness to cycling stress and retention over 10⁴ s for more than 5-bit states in the switching conductance range are achieved. Moreover, the contribution of the Al₂O₃ layer to the retention characteristic is investigated through filament morphology observation using transmission electron microscopy (TEM) and copper migration component analysis. This study provides a practical approach to developing highly reliable memristors with exceptional switching performance.     

复合气相缓蚀剂对纯铜缓蚀的研究

铜应用广泛,但在湿度较高的腐蚀性介质中其易被腐蚀,采用苯骈三氮唑(BTA)和酚类W制成一种新型复合气相缓蚀剂,采用原子分光光度计和电化学测试方法、扫描电镜和激光拉曼显微镜研究了该复合气相缓蚀剂对纯铜的缓蚀性能及其缓蚀机理.结果表明,该复合气相缓蚀剂在铜表面形成的膜是一种自组装缓蚀膜,具有很好的防蚀和拒水性能.     

Microstructural Characterization of the Shear Bands in Fe-Cr-Ni Single Crystal by EBSD

An investigation has been made into the microstructural characterization of the shear bands generated under high-strain rate （≈10^4 s^-1） deformation in Fe-15%Cr-15%Ni single crystal by EBSD-SEM （electron backscatter diffraction-scanning electron microscopy）, TEM （transmission electron in microscopy） and HREM （high- resolution electron microscopy）. The results reveal that the propagation of the shear band exhibits an asymmetrical behavior arising from inhomogenous distribution in plasticity in the bands because of different resistance to the collapse in different crystallographic directions; The γ-ε-α′phase transformations may take place inside and outside the bands, and these martensitic phases currently nucleate at intersections either between the twins and deformation bands or between the twins and ε-sheet. Investigation by EBSD shows that recrystallization can occur in the bands with a grain size of an average of 0.2μm in diameter. These nano-grains are proposed to attribute to the results of either dynamic or static recrystallization, which can be described by the rotational recrystallization mechanism. Calculation and analysis indicate that the strain rate inside the shear band can reach 2.50×10^6 s^-1, which is higher, by two or three orders of magnitude, than that exerted dynamically on the specimen tested.     

Using a modified genetic algorithm to find feasible regions of a desirability function

The multi‐response optimization (MRO) problem in response surface methodology is quite common in applications. Most of the MRO techniques such as the desirability function method by Derringer and Suich are utilized to find one or several optimal solutions. However, in fact, practitioners usually prefer to identify all of the near‐optimal solutions, or all feasible regions, because some feasible regions may be more desirable than others based on practical considerations. In this paper, with benefits from the stochastic property of a genetic algorithm (GA), we present an innovative procedure using a modified GA (MGA), a computational efficient GA with a local directional search incorporated into the GA process, to approximately generate all feasible regions for the desirability function without the limitation of the number of factors in the design space. The procedure is illustrated through a case study. The MGA is also compared with other commonly used methods for determining the set of feasible regions. Using Monte Carlo simulations with two benchmark functions and a case study, it is shown that the MGA can more efficiently determine the set of feasible regions than the GA, grid methods, and the Nelder–Mead simplex algorithm. Copyright © 2011 John Wiley & Sons, Ltd.     

LCA在铜工业中的应用现状及发展趋势

虽然我国是铜生产和消费大国,但依然面临突出的供需矛盾问题。同时,铜工业对环境造成的污染问题不利于我国的可持续发展。为了优化铜工业生产过程,实现资源的综合利用和提高经济效益,已有相关学者利用生命周期评价(LCA)这一国际认可的环境管理工具来评估铜工业的环境影响与能源消耗。总结分析了LCA在铜工业中的应用现状,针对应用过程中的不足之处,提出了未来的发展趋势,为推动铜工业节能减排的实施及标准体系的构建提供有力支持。     

镍基单晶高温合金小角度晶界的形成机制、影响因素与控制措施

镍基单晶高温合金被广泛用于制备先进航空发动机及工业燃气轮机的关键热端部件,随着铸件结构的复杂化和大型化以及合金中难熔元素的增多,凝固缺陷的形成倾向增大。其中,小角度晶界是定向凝固制备单晶高温合金铸件过程中经常出现的一类缺陷,它会破坏单晶的完整性,一旦超过容限就会对铸件的力学性能造成恶劣影响,随着单晶高温合金服役温度的不断提高,小角度晶界对性能的损害会更为严重。因此,小角度晶界日益成为镍基单晶高温合金发展和应用中需要解决的重要课题,受到国内外研究者的广泛关注。单晶中的小角度晶界与传统意义上的小角度晶界有所不同,是指相邻枝晶间的取向偏离。研究者们在不同晶界偏离角及不同温度条件下就小角度晶界对合金持久性能、蠕变性能及疲劳性能的影响进行了研究,结果发现:当偏离角较小时,小角度晶界对合金性能的影响并不明显,但是随着偏离角的增大及温度的升高,合金的性能均会降低。为了探寻有效的预防和控制措施,研究者们就小角度晶界的形成机制及影响因素进行了研究。关于小角度晶界的形成机制,被大家普遍认同的观点是:枝晶在分枝生长过程中发生了塑性变形,从而导致了枝晶的取向偏离,当枝晶再次汇聚时就会产生小角度晶界。但是,关于枝晶变形的原因则没有一致看法。另外,关于小角度晶界影响因素的研究还不是很系统,主要集中在合金成分及晶界强化元素、凝固参数及取向、铸件尺寸等方面。镍基单晶高温合金中的小角度晶界归根结底是由枝晶的取向偏离导致的,而取向偏离的影响因素复杂,因此小角度晶界的出现很难完全避免。目前,主要通过取向控制以减少小角度晶界的产生,并通过晶界强化以提高合金对小角度晶界的容限。本文阐明了单晶高温合金中的小角度晶界的概念,总结了小角度晶界对合金力学性能的影响,综述了小角度晶界形成机制的研究进展,分析了合金元素、微量元素、凝固条件和铸件结构等因素对小角度晶界形成的影响,在此基础上,提出了减少小角度晶界的措施和强化晶界的途径,最后就未来的研究方向进行了展望。     

Polymer Light-Emitting Diode Using a New Electrophosphorescent Cyclometalated Iridium Complex

A new iridium-based cyclometalated complex, namely bis (2-phenylpyridine-C², N') iridium (III) picolinate [(ppy)₂Ir(pic)] is synthesized and investigated as electrophosphorescent dopant in polymer-based organic light-emitting diodes. The photoluminescence emission from this complex is observed at 501 nm, with a shoulder at 526 nm. Poly(N-vinylcarbazole) (PVK) is used as host polymer and single-layer devices of PVK doped with (ppy)₂Ir(pic) complex are fabricated. Photoluminescence (PL) spectra of PVK films doped with different concentration of iridium complex were measured to study the possible energy transfer occurring between PVK to iridium complex. A predominant blue to a completely green shifted emission is observed when the doping concentration was increased from 0% to 5 wt%. Optical and atomic force microscopic images of the doped films indicate a smooth film formation when spin coated with chlorobenzene as a solvent as compared to chloroform. Electroluminescence spectra of ITO/PEDOT:PSS/PVK:(ppy)₂Ir(pic)/Al device resembles that of the PL spectra with emission at 507 nm and Commission Internationale de l'Eclairage (CIE) coordinates (0.29, 0.57).     

MFC-Based Structural Health Monitoring Using a Miniaturized Impedance Measuring Chip for Corrosion Detection

This article presents an experimental study using an active sensing device that consists of a miniaturized impedance-measuring chip (AD5933) and a self-sensing macrofiber composite (MFC) patch to detect corrosion in aluminum structures widely used for aerospace, civil, and mechanical systems. A simple beam structure made from a 6063 T5 aluminum alloy was selected for corrosion-detection testing. Four different corrosion cases with two different locations and two different degrees at each location were artificially inflicted on the beam using hydrochloric (HCI) acid. To identify the degrees and locations of the corrosion, the electromechanical impedance-based damage-detection technique using the proposed active sensing device was investigated. Root-mean-square deviation (RMSD) metric of the real part of the impedances obtained from the MFC patch was selected as a damage-sensitive feature. Experimental results have verified that the proposed approach can be an effective tool for detection and quantification of corrosion in aluminum structures.