表面化学反应中间生成物的检测

对催化反应的各种中间生成物实施检测以直接确定反应的基元步骤、路径和机理，是研究表面催化反应的有效手段。探索一种检测化学中间生成物的方法是一个意义重大的课题。本文提出了用激光脉冲成象原子探针（Ｐｕｌｓｅｄ－ＬａｓｅｒＩｍａｇｉｎｇＡｔｏｍ－Ｐｒｏｂｅ，ＰＬＩＡＰ）［１］研究表面催化反应的方法，并对运用ＰＬＩＡＰ检测表面催化反应中间生成物的实验条件和实验结果的真实性进行了概括和探讨。     

光纤通信系统中的光检测器件

论文介绍运用在光纤通信系统中的光检测器件的结构，工作原理及性能，并对ＰＩＮ和ＡＰＤ两种光检测器件进行了比较。     

单元结构和维持电压对表面放电型AC-PDP光电特性的影响

单元结构和维持电压对ＡＣ－ＰＤＰ的性能有非常大的影响。依据国内外研究人员所做的相关实验,全面总结了这两方面因素对表面放电型ＡＣ－ＰＤＰ光电特性的影响,并从理论上给予解释。最后归纳出表面放电型ＡＣ－ＰＤＰ单元结构的设计步骤和确定维持电压的原则。     

RF－PECVD制备类金刚石碳膜的沉积机理

本文综合评述了用射频等离子体化学气相沉积（ＲＦ－ＰＥＣＶＤ）法制备类金刚石碳膜过程中的等离子体化学反应和等离子体与材料表面反应机理的研究概况。着重介绍射频ＣＨ＿４等离子体中，各种离子和中性基因的产生和传输机理，以及等离子体与材料表面反应的动力学基本理论。     

贵金属纳米颗粒催化刻蚀硅表面微纳结构现状北大核心

简述了目前一些贵金属纳米颗粒催化刻蚀Si表面微纳结构的研究工作,并叙述了催化刻蚀反应的主要过程。在系统介绍催化刻蚀化学反应机理的基础上,对催化刻蚀的阴极、阳极反应进行了细致的探讨。根据不同的阳极和阴极反应方程式,讨论了不同的中间产物以及不同中间产物在反应中的作用机理。然后介绍了贵金属纳米颗粒的物理法和化学法两种制备方法。结合目前国内外研究进展,讨论了贵金属纳米颗粒种类、尺寸以及溶液成分比例对硅表面微纳结构的影响。最后对贵金属纳米颗粒催化刻蚀硅表面微纳陷光结构的未来前景进行了展望。     

半绝缘GaAs的表面光伏谱研究

利用表面光伏法（ＳＰＶ）研究了半绝缘ＧａＡｓ（ＳＩ－ＧａＡｓ）的缺陷态,通过加直流光偏置测量了室温下带边以下的光伏响应,发现带隙内缺陷态的光伏向应主要是由于表面复合而在样品表面形成协流子浓度梯度引起的,通过实验表明ＳＰＶ是一种对ＳＩ－ＧａＡｓ晶片表面质量进行检测的非常灵敏的无损检测方法。     

交流彩色等离子体显示器（Ⅰ）

彩色等离子体显示器具有许多独特的特点，最适宜用于大屏幕壁挂高清晰度电视。从目前的技术发展状况看，单基板表面放电型ＡＣＰＰ最具潜力。本文详细分析了ＡＣＰＤＰ的工作原理和采用的多种关键技术，并对彩色ＰＤＰ的发展前景作了展望。     

彩色PDP的放电特性及发光机理

简述彩色等离子显示屏的发展历史和现状。从低压气体放电的基本特性出发,分析彩色ＰＤＰ放电的基本特性。阐述ＡＣ ＰＤＰ的充气气压一定时,在理论上存在一个极限分辨率,以充信Ｎｅ－Ｘｅ混合气体的表面型ＡＣ ＰＤＰ为例,说明ＰＤＰ的发光机理。最后,从气体的电离电位出发,讨论降低ＰＤＰ着火电压的几种途径。     

AC PDP介质保护膜材料的选择

随着对交流等离子体显示板电压变化原因的探讨，新型表面保护材料的开发研究以及为除去污染而对制造工艺的调整，ＡＣＰＤＰ正在获得极好寿命特性。介质保护膜直接与放电气体相接触，其材料和表面状况是决定ＡＣＰＤＰ寿命及放电性的重要因素，因而保护膜材料的选择尤为重要。     

航天工业用电路DPA中键合强度失效分析

本文通过对一批高可靠集成电路ＤＰＡ试验失效机理的分析，证明了ＤＰＡ试验对剔除电子元器件不合格批次、提高产品可靠性确实有效，并为生产厂家对生产工艺的改进提供了科学依据。     

A Comparison of One- and Two-Dimensional Classification of Hemagglutination Reactions in Microplates

The ability of a two-dimensional classification system to improve detection of weak hemagglutination reactions was investigated. Two canonical variables were derived by stepwise linear discriminant techniques from a set of 24 measurements of light absorbance for each of 605 hemagglutination reactions. A test set of 3864 reactions were then classified by the k nearest neighbor algorithm using either the first canonical variable or both variables. No improvement in the ability to distinguish positive reactions from negative ones was found when the second canonical variable was added. This implies that all of the information about hemagglutination reactions in microplates is contained in the first canonical variable. Thus, computationally expensive two-dimensional pattern classifiers will not improve the performance of automated microplate hemagglutination detection. It appears that it will be necessary to reduce the size of the light beam used to measure light absorbance in order to improve detection of weak reactions.     

Real‐Time Imaging of Nanoscale Redox Reactions over Bimetallic Nanoparticles

The catalytic performance of bimetallic nanoparticles (NPs) strongly depends on their structural and compositional changes under reaction conditions. At the fundamental level, these changes are driven by redox reactions that occur on the surface of the NPs. The degree of complexity in the redox reactions is further amplified in bimetallic NPs because both metals can have their own reactions with the reactant molecules, in addition to any synergistic effects between the metal nanocatalysts and their reducible oxides. Here, the gas phase oxidation and reduction reactions, and the oxidation of carbon monoxide (CO) over Pt–Ni rhombic dodecahedron NPs with segregated Pt frames and Pt–Ni alloy NPs are investigated using in situ gas cell transmission electron microscopy. The real‐time observations show that NiO shell formation and Pt segregation are two important features during the oxidation and reduction of Pt–Ni NPs, respectively. Moreover, the two types of NPs evolved in different ways. By combining high‐resolution imaging, mass spectroscopy, and modeling, it is shown that the evolution of NP morphology and composition during redox reactions plays an important role in controlling the catalytic activity of the NPs.     

Facile Room‐Temperature Anion Exchange Reactions of Inorganic Perovskite Quantum Dots Enabled by a Modular Microfluidic Platform

In an effort to produce the materials of next‐generation photoelectronic devices, postsynthesis halide exchange reactions of perovskite quantum dots are explored to achieve enhanced bandgap tunability. However, comprehensive understanding of the multifaceted halide exchange reactions is inhibited by their vast relevant parameter space and complex reaction network. In this work, a facile room‐temperature strategy is presented for rapid halide exchange of inorganic perovskite quantum dots. A comprehensive understanding of the halide exchange reactions is provided by isolating reaction kinetics from precursor mixing rates utilizing a modular microfluidic platform, Quantum Dot Exchanger (QDExer). The effects of ligand composition and halide salt source on the rate and extent of the halide exchange reactions are illustrated. This fluidic platform offers a unique time‐ and material‐efficient approach for studies of solution phase‐processed colloidal nanocrystals beyond those studied here and may accelerate the discovery and optimization of next‐generation materials for energy technologies.     

Modulating the Photocatalytic Activity of Graphene Quantum Dots via Atomic Tailoring for Highly Enhanced Photocatalysis under Visible Light

Precise control over doping of photocatalysts is required to modulate their photocatalytic activity in visible light‐driven reactions. Here, a single precursor‐employing bottom‐up approach is developed to produce different heteroatom‐doped graphene quantum dots (GQDs) with unique photocatalytic activities. The solvothermal reaction of a norepinephrine precursor with redox active and condensable moieties effectively produces both nitrogen/sulfur codoped GQDs (NS‐GQDs) and nitrogen‐doped GQDs (N‐GQDs) by simply varying solvents (from dimethyl sulfoxide to water) under microwave irradiation. As‐prepared NS‐GQDs and N‐GQDs show similar lateral sizes (3–4 nm) and heights (1–2 nm), but they include different dopant types and doping constitution and content, which lead to changes in photocatalytic activity in aerobic oxidative coupling reactions of various amines. NS‐GQDs exhibit much higher photocatalytic activity in reactions under visible light than N‐GQDs and oxygen‐doped GQDs (O‐GQDs). The mechanism responsible for the outstanding photocatalytic activity of NS‐GQDs in visible light‐driven oxidative coupling reactions of amines is also fully investigated.     

Decoupling Interfacial Reactions at Anode and Cathode by Combining Online Electrochemical Mass Spectroscopy with Anode-Free Li-Metal Battery

It is essential to decouple the interfacial reactions taking place at the anode and cathode in rechargeable batteries. However, due to the reactive nature of Li, it is challenging to use Li-metal batteries (LMBs) protocol to decouple the interfacial reactions. The by-products from the anode or cathode become mixed in Li/NMC111 cells, which make decoupling interfacial reactions difficult. Here, reactions at electrodes are successfully decoupled and demystified using a protocol combining anode-free LMB (AFLMB) with online electrochemical mass spectroscopy. LiPF₆ in ethylene carbonate (EC)/diethyl carbonate (DEC) and EC/ethyl methyl carbonate (1:1 v/v%) electrolytes are used to compare interfacial reactions in Li/NMC111 and Cu/NMC111 cells. In Cu/NMC111, the evolution of CO₂, CO, and C₂H₄ gases at the initial stage of first charging is due to interfacial reactions at Cu surface due to solid–electrolyte-interphase formation. However, the evolution of CO₂ and CO gases at high voltage in the entire cycles is associated with chemical and/or electrochemical electrolyte oxidation at the cathode. This work paves a new concept to decouple interfacial reactions at electrodes for developing electrochemically stable electrolytes to improve the performance with the long-cycling life of AFLMBs and LMBs.     

Effects of humorous heroes and villains in violent action films

This experimental investigation explores the use of humor in violent action films, focusing on the effects of wisecracking heroes and villains on audience distress. An action film was edited to create control film versions without wisecracking dialogue. The research revealed contrast effects. Among female viewers, hero wisecracks in an action film increased distress reactions to the film, but lessened distressful reactions to subsequent televised depictions of real, nonhumorous violence. Conversely, males exposed to hero humor found the film marginally less distressing, but rated depictions of real violence more distressing. For all viewers, effects of villain wisecracks tended to parallel females' reactions to hero wisecracks. Disposition theory is offered as a plausible explanations of study findings.     

Biomimetic Structural Electrochemistry from Conducting Polymers: Processes,Charges, and Energies. Coulovoltammetric Results from Films on Metals Revisited

Oxidation/reduction reactions in films of conducting polymers exchanging anions and solvent during reactions are revisited here and explored by voltammetric and coulovoltammetric results using Pt electrodes coated with films of different polymers, in different solvents and salts. The reactions induce molecular (conformational) and macroscopic (relaxation, swelling, shrinking, and compaction) structural changes. Coulovoltammetric loops constitute a direct graphical tool to identify, separate, and quantify the structural components of the reversible film reactions together the potential domains and the charges involved in irreversible reactions. Any abrupt slope variation is related to abrupt changes of the reaction rate associated with each of the structural induced processes. Charges, energies, and characteristic potentials for any of the structural or irreversible process are obtained. Reversible film reactions are present from –1.5 to 0.35 V versus Ag/AgCl, overlapping the irreversible hydrogen evolution at the metal/polymer interface below –1.1 V. Structural reduction energies are higher than structural oxidation energies and structural changes are energetically asymmetric. 3D reactive structural memories are envisaged stepping up storage density by orders of magnitude. Conducting polymers are 3D structural gel reactors at the polymer chain level: large anions in solution cannot penetrate inside the film. Composition changes and structural processes mimic intracellular matrix (ICM) biological reactions.     

腐蚀性溶液介电常数测量的探头研究

测量化学反应物的介电常数,必须对测量探头进行保护,采用FDTD方法在圆柱坐标下对一种有保护层的新型同轴线探头进行分析计算,得到了被测物介电常数与反射系数之间的关系。对圆柱中心以及薄层结构进行了特殊处理。计算结果与实验值吻合。     

Versatile,Stable, and Scalable Gel-Like Aerophobic Surface System (GLASS) for Hydrogen Production

Facile removal of adsorbed gas bubbles from electrode surfaces is crucial to realize efficient and stable energy conversion devices based on electrochemical gas evolution reactions. Conventional studies on bubble removal have limited applicability and scalability due to their reliance on complex and energy/time-intensive processes. In this study, a simple and versatile method is reported to fabricate large-area superaerophobic electrodes (up to 100 cm²) for diverse gas evolution reactions using the gel-like aerophobic surface system (GLASS). GLASS electrodes are readily and uniformly fabricated by simple spin-coating and cross-linking of polyallylamine on virtually any kinds of electrodes within 5 min under ambient conditions. Intrinsically hydrophilic gel overlayers with interconnected open pores allow the physical separation of bubble adhesion and catalytic active sites, reducing bubble adhesion strength, and promoting the removal of gas bubbles. As a result, GLASS electrodes exhibit greatly enhanced efficiency and stability for diverse gas evolution reactions, such as hydrogen evolution, hydrazine oxidation, and oxygen evolution reactions. This study provides deeper insights into understanding the effect of the hydrophilic microenvironment on gas evolution reactions and designing practical electrochemical devices.