基于裂结技术的单分子尺度化学反应研究进展

分子电子学是研究单分子器件的构筑、性质以及功能调控的一门新兴学科。其中,金属/分子/金属结的构筑和表征是现阶段分子电子学的主要研究内容。裂结技术是当前分子电子学研究的主要实验方法,主要包括机械可控裂结技术和扫描隧道显微镜裂结技术。本文对裂结技术进行了介绍,并对近年来利用这些技术,在单分子尺度化学反应的检测和动力学研究,以及将这些技术与溶液环境、静电场、电化学门控等方法相结合,调控单分子器件的电输运性质等方面所取得的进展进行了概述。国家重点研发计划(2017YFA0204902);;\n福建省自然科学基金(2016J05162)资助项目~

A New Random Walk Simulation Model for Study of Diffusion Behavior of Single Particle Within Two-Dimensional Space

分子的扩散行为是微观化学的重要研究领域. 影响扩散行为的因素很多，但是目前各个因素的具体影响效果还不明确. 作者基于随机行走理论建立了分子在二维空间的扩散模型，依据此模型自主开发了模拟软件以及数据分析系统，并利用该模拟软件系统研究了势垒尧横向速度等因素对扩散行为的影响，验证了该模型的可靠性，证明根据该模型可以得到和实验尧理论相吻合的结果. 该软件有望成为模拟微观化学扩散行为的潜在平台，如电化学以及膜过滤过程中的扩散.Research on diffusion behaviors is of significant value in that it is closely related to transport phenomena in micro-chemistry. However, the effects of variables on diffusion are still unclear. Here, we developed and programmed a simulation methodology along with data analysis, which was capable to simulate the diffusion of a particle within twodimensional heterogeneous space in large timescale; the effects of periodically arranged impenetrable barriers of specific shape and lateral drifting velocity on diffusion behavior were studied. As well as standard mean square displacement analysis, a new method, the appearance probability distribution method, was introduced, which revealed whether the particle tended to be present at certain positions. This article introduced the construction of the simulation model and demonstrated the validity of the model. The results showed that our model fit qualitatively well with experiments and theories. The model was proved to be an excellent potential platform for simulating the diffusion behaviors in micro-chemistry, such as the diffusion process in electrochemistry as well as nanofiltration membrane.This work was supported by National Basic Research Program of China (973 Program, 2010CB732400), the National Natural Science Foundation of China (NSFC) (20821063, 20873063, 51071084, and 21273113), the Natural Science Foundation of Jiangsu Province (BK2010389).This work was supported by National Basic Research Program of China (973 Program, 2010CB732400), the National Natural Science Foundation of China (NSFC) (20821063, 20873063, 51071084, and 21273113), the Natural Science Foundation of Jiangsu Province (BK2010389).作者联系地址：南京大学 化学化工学院, 生命分析化学国家重点实验室, 江苏 南京 210008Author's Address: State Key Lab of A nalytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210008, China通讯作者E-mail：[email protected]

一种城轨列车齿式联轴节结构设计与试验研究

根据城轨列车驱动电机与齿轮箱之间连接的需要，设计了用于城轨列车的一种齿式联轴节。在设计过程中，从齿式联轴节结构、齿部的几何参数、密封结构、齿部侧隙的理论计算、空间运动分析等方面进行了研究；建立了齿式联轴节的三维模型，基于Ansys计算软件对齿式联轴节的3种运行工况进行了有限元分析，并运用ZGCAD齿轮软件进行了齿轮强度计算；设计制造齿式联轴节样机，进行了样机周期性循环试验。研究结果可为其他领域齿式联轴节的设计提供借鉴和参考

一种用于粉末原料运输转移的装置

本发明公开了一种用于粉末原料运输转移的装置，包括设备外壳，所述设备外壳上安装有一料筒，同时，所述设备外壳内还设置有控制器，以及与控制器相连的直线送料器、计量秤斗、称重传感器和卸料斗，其中所述直线送料器位于料筒出料口下方，所述计量秤斗位于所述直线送料器的尾端，包括上端口、下端口，同时，所述称重传感器通过连接件连接于所述计量秤斗上，且所述卸料斗位于所述下端口处。本设备是专门针对于密胺制品研发，相对于市面上的其他设备，主要优点是结构简单，造价低廉，易清理，能满足使用不同颜色粉料的要求，占地空间小，能基本满足密胺制品的基本需求

日光诱导叶绿素荧光估算中国典型生态系统总初级生产力的能力

陆地生态系统总初级生产力(GPP,Gross Primary Productivity)是陆地生态系统碳循环的重要分量,提高其估算精度具有重要的科学意义。由于受多种因子的影响,GPP的时空变异明显,其估算结果存在较大的不确定性。日光诱导叶绿素荧光(SIF,Sun-Induced Chlorophyll Fluorescence)与GPP密切相关,近年来被应用于估算区域和全球GPP,但其在中国生态系统的适用性尚不清楚。以中国8个典型植被生态系统为研究对象,驱动两叶光能利用率模型(TL-LUE,TwoLeaf Light Use Efficiency Model)模拟以站点为中心0.5°×0.5°区域内的月GPP,验证SIF估算GPP的能力。结果表明,SIF具有监测中国典型植被生态系统GPP的能力,月SIF与TL-LUE模拟的月GPP之间显著相关,其中5个生态系统中两者的R2高于0.8,最高达到0.91,GPP与SIF变化的斜率随生态系统类型变化。模拟的GPP与SIF遥感数据的季节变化特征相同,两者之间的一致性在生长季节好于非生长季节;SIF能更好地监测农田GPP的季节变化

Studies and Progresses on Hole Metallization in High-Density Interconnected Printed Circuit Boards

孔金属化互连是印制电路板（PCB）高密度集成的核心制程之一,化学镀铜和电子电镀铜是实现孔金属化的关键技术。本文介绍HDI-PCB的概念和制作流程;综述化学镀铜和电子电镀铜孔金属化互连的研究和进展,包括溶液组成和操作条件的影响,添加剂及其相互作用机理,以及盲孔填充和通孔孔壁加厚机制;展望高密度互连印制电路板电子电镀基础研究及新技术发展方向。Printed circuit boards (PCBs) are almost the core components of all electronic systems. With the rapid development of sciences and technologies, PCBs are gradually developing in the direction of multi-layer, thin and high-density wiring due to the functionalization, miniaturization, lightweight and high reliability of electronic products, as well as the widespread popularization of the subminiature package such as chip scale package (CSP) and ball grid array (BGA). Therefore, High-density interconnected printed circuit boards (HDI-PCBs) arise. Hole metallization is one of the core technologies in HDI-PCBs and includes two processes composed of conductive treatment and electron electroplating. Electroless copper plating, as one of the conductive treatment methods, not only can deposit a copper layer with excellent conductivity and adhesion, but also has more reliable process maturity. However, reducing agent formaldehyde harms human health and environment. As a relatively eco-friendly and cheap reducing agent, hypophosphite is expected to replace formaldehyde in the process of the electroless copper plating if the copper deposition rate and the coating quality can be improved. Electron copper electroplating is closely related to the electrical properties of the electronic products. With the increase of PCBs integration, the diameters of holes decrease and the aspect ratios increase, which makes blind microvia and through hole more difficult to realize the superfilling and conformal thickening, respectively. For the superfilling of blind microvia, there are some mature models. But for the conformal thickening of through hole, there is no applicable theoretical guidance, and therefore, more studies are needed. It is very important to find suitable and novel additives besides the improvement of plating conditions for electron copper electroplating. In acidic sulfate copper electron electroplating process, although there are lots of studies on the additives, the interaction mechanism of the additives still needs to be further revealed, which not only contributes to understand the molecular mechanism of various additives, but also provides theoretical basis and guidance for the design and development of novel and efficient additives. In addition, the research and development of weakly alkaline and neutral electron copper electroplating process are also important for hole metallization of HDI-PCB. This paper firstly describes the concept of HDI-PCB, and then reviews recent studies and progresses on the electroless copper plating and acidic sulfate copper electron electroplating processes, which involves the effects of bath composition and operating conditions, the interactive mechanism of additives, and the filling and thickening mechanisms of the holes. Finally, the future directions towards basic research and novel electron electroplating development are highlighted.国家自然科学基金项目(21972118)通讯作者:杨防祖,孙世刚E-mail:[email protected];[email protected]:Fang-ZuYang,Shi-GangSunE-mail:[email protected];[email protected]厦门大学化学化工学院,固体表面物理化学国家重点实验室,福建 厦门 361005College of Chemistry and Chemical Engineering, State Key Laboratory of Physical Chemistry of Solid Surfaces, Xiamen University, Xiamen 361005, Fujian Chin

当代乡村建设中的艺术实践

在中国社会的现代转型中,乡村付出了沉重的代价。时至今日,中国乡村的危机非但没有缓解,反而随着政治运动以及资本侵蚀,陷入到空壳化、原始化的险境之中,陷入到荒漠与冷漠的生态与世态之中。艺术介入乡村的实践,即是重新探索城乡建设与社区营造的各种可能性,以此实现对文明传统的再追索及当下社会的再修复。北京大学人文社会科学研究院于2016年7月28日组织召开"乡村建设及其艺术实践"学术研讨会,基于上述主题展开讨论

2000–2010年中国典型陆地生态系统实际蒸散量和水分利用效率数据集

蒸散是陆地生态系统水分循环和能量平衡的关键过程,水分利用效率是反映生态系统碳水循环间耦合关系的重要指标,二者在生态学、农学、水文学、气候学等多个学科中均具有重要的应用价值。涡度相关法被认为是现今唯一能直接测量生物圈与大气间物质与能量交换通量的标准方法,已成为生态系统尺度碳水交换通量观测的主要方法。本文通过整合中国陆地生态系统通量观测联盟(China FLUX)的长期观测数据和中国区域其他观测站点基于涡度相关法发表的文献数据,构建了一套中国典型陆地生态系统实际蒸散量和水分利用效率数据集。本数据集共有实际蒸散量数据记录143条、水分利用效率数据记录96条,涉及5种生态系统类型45个生态系统,时间跨度为2000–2010年。本数据集可以为陆地生态系统碳水循环、生态系统管理和评估、全球变化等相关领域的研究提供数据支持