语义驱动的集成化产品建模

针对复杂产品研发过程中多领域协同对产品知识共享和重用的需求,提出一种语义驱动的集成化产品建模方法.结合多本体技术,给出了集成化产品建模框架,该框架由概念层和模型层构成,概念层包括高层核心产品本体和领域本体,模型层由主模型和领域模型等一族模型构成;同时还给出了集成化产品模型的形式化语义描述,在构建高层核心产品本体的基础上建立主模型;基于多领域本体,进行由概念层语义驱动的领域模型快速重构,在语义理解基础上实现跨领域的产品知识重用.     

Artificial convolution neural network techniques and applications for lung nodule detection

We have developed a double-matching method and an artificial visual neural network technique for lung nodule detection. This neural network technique is generally applicable to the recognition of medical image pattern in gray scale imaging. The structure of the artificial neural net is a simplified network structure of human vision. The fundamental operation of the artificial neural network is local two-dimensional convolution rather than full connection with weighted multiplication. Weighting coefficients of the convolution kernels are formed by the neural network through backpropagated training. In addition, we modeled radiologists' reading procedures in order to instruct the artificial neural network to recognize the image patterns predefined and those of interest to experts in radiology. We have tested this method for lung nodule detection. The performance studies have shown the potential use of this technique in a clinical setting. This program first performed an initial nodule search with high sensitivity in detecting round objects using a sphere template double-matching technique. The artificial convolution neural network acted as a final classifier to determine whether the suspected image block contains a lung nodule. The total processing time for the automatic detection of lung nodules using both prescan and convolution neural network evaluation was about 15 seconds in a DEC Alpha workstation.     

The design of the TEI encoding scheme

This paper discusses the basic design of the encoding scheme described by the Text Encoding Initiative'sGuidelines for Electronic Text Encoding and Interchange (TEI document number TEI P3, hereafter simplyP3 orthe Guidelines). It first reviews the basic design goals of the TEI project and their development during the course of the project. Next, it outlines some basic notions relevant for the design of any markup language and uses those notions to describe the basic structure of the TEI encoding scheme. It also describes briefly the core tag set defined in chapter 6 of P3, and the default text structure defined in chapter 7 of that work. The final section of the paper attempts an evaluation of P3 in the light of its original design goals, and outlines areas in which further work is still needed.C. M. Sperberg-McQueen is a Senior Research Programmer at the academic computer center of the University of Illinois at Chicago; his interests include medieval Germanic languages and literatures and the theory of electronic text markup. Since 1988 he has been editor in chief of the ACH/ACL/ALLC Text Encoding Initiative. Lou Burnard is Director of the Oxford Text Archive at Oxford University Computing Services, with interests in electronic text and database technology. He is European Editor of the Text Encoding Initiative's Guidelines.     

Functional 2D Phases in Mixed Dimensional Perovskite Photovoltaics

Organic-inorganic hybrid perovskite solar cells (PSCs) with unique properties exhibit their powerful competitiveness in the photovoltaic field over the past few years. However, the challenges of stability for perovskite devices limit the commercialization and further development. The 2D/3D hybrid structures combine the superior efficiency of bulk perovskites and the superior stability of layered perovskites and gradually get hotspots of the photovoltaic field. In addition, there remains a lack of comprehensive understanding and systematic summary of the function of 2D perovskite attributed to the complex nature of 2D/3D structures. Here, the latest progress of 2D/3D hybrid structures and focus on the functionality of 2D phases in mixed structures and the underlying mechanism from the perspective of their different distributions in the perovskite layer is summarized. Then, the insight and vital factors for overall improvements in the stability of 2D/3D structures are thoroughly discussed. Finally, it is expected that this review will contribute to the present challenges and future research prospects in the photovoltaic industry.     

Surface Oxygen Coordination of Hydrogen Bond Chemistry for Aqueous Ammonium Ion Hybrid Supercapacitor

Aqueous ammonium ion hybrid supercapacitor (A-HSC) combines the charge storage mechanisms of surface adsorption and bulk intercalation, making it a low-cost, safe, and sustainable energy storage candidate. However, its development is hindered by the low capacity and unclear charge storage fundamentals. Here, the strategy of phosphate ion-assisted surface functionalization is used to increase the ammonium ion storage capacity of an α-MoO₃ electrode. Moreover, the understanding of charge storage mechanisms via structural characterization, electrochemical analysis, and theoretical calculation is advanced. It is shown that NH₄⁺ intercalation into layered α-MoO₃ is not dominant in the A-HSC system; rather, the charge storage mainly depends on the adsorption energy of surface “O” to NH₄⁺. It is further revealed that the hydrogen bond chemistry of the coordination between “O” of surface phosphate ion and NH₄⁺ is the reason for the capacity increase of MoO₃. This study not only advances the basic understanding of rechargeable aqueous A-HSC but also demonstrates the promising future of surface engineering strategies for energy storage devices.     

融合通道位置注意力机制和并行空洞卷积的人脸年龄合成

目的 人脸年龄合成旨在合成指定年龄人脸图像的同时保持高可信度的人脸,是计算机视觉领域的热门研究方向之一。然而目前主流人脸年龄合成模型过于关注纹理信息,忽视了与人脸相关的多尺度特征,此外网络存在对身份信息筛选不佳的问题。针对以上问题,提出一种融合通道位置注意力机制和并行空洞卷积的人脸年龄合成网络（generative adversarial network（GAN）composed of the parallel dilated convolution and channel-coordinate attention mechanism,PDA-GAN）。方法 PDA-GAN基于生成对抗网络提出了并行三通道空洞卷积残差块和通道—位置注意力机制。并行三通道空洞卷积残差块将3种膨胀系数空洞卷积提取的不同尺度人脸特征融合,提升了特征尺度上的多样性和总量上的丰富度;通道—位置注意力机制通过对人脸特征的长度、宽度和深度显著性计算,定位图像中与年龄高度相关的通道和空间位置区域,增强了网络对通道和空间位置上敏感特征的表达能力,解决了特征冗余问题。结果 实验在Flickr高清人脸数据集（Flickr-faces-high-quality,FFHQ）上训练,在名人人脸属性高清数据集（large-scale celebfaces attributes dataset-high quality,Celeba-HQ）上测试,将本文提出的PDA-GAN与最新的3种人脸年龄图像合成网络进行定性和定量比较,以验证本文方法的有效性。实验结果表明,PDA-GAN显著提升了人脸年龄合成的身份置信度和年龄估计准确度,具有良好的身份信息保留和年龄操控能力。结论 本文方法能够合成具有较高真实度和准确性的目标年龄人脸图像。     

双脉冲激光诱导铝等离子体的双波长干涉诊断

双脉冲激光诱导等离子体在激光加工、元素检测、材料去除等领域有广阔的应用前景和发展空间,对其进行诊断具有重要意义。针对延迟双脉冲激光诱导铝等离子体的作用效果和影响机理,采用双波长干涉法对其时间演化规律展开研究。基于马赫-曾德尔干涉仪搭建了双波长干涉诊断系统,得到了双脉冲激光诱导等离子体干涉图。通过对干涉图的处理和分析,得到了等离子体电子密度随双脉冲激光延迟时间的变化规律。结果表明,随着双脉冲激光延迟时间的增加,第二束脉冲激光对等离子体电子密度的增强效果先加强后减弱。其中,双脉冲激光延迟时间为10 ns时,对等离子体电子密度的增强效果最强,在30 ns时刻,其中心区域平均电子密度可达6.49×1019 cm?3,相较于同等能量单脉冲激光诱导等离子体提升了26%。同时研究了延迟时间对第二束脉冲激光作用机制的影响。研究结果为双脉冲激光诱导等离子体的优化方向提供了参考。     

Fast in situ 3D nanoimaging: a new tool for dynamic characterization in materials science

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Synthesis of large-scale atomic-layer SnS<Subscript>2</Subscript> through chemical vapor deposition

Two-dimensional layers of metal dichalcogenides have attracted much attention because of their ultrathin thickness and potential applications in electronics and optoelectronics.Monolayer SnS2,with a band gap of ～2.6 eV,has an octahedral lattice made of two atomic layers of sulfur and one atomic layer of tin.Till date,there have been limited reports on the growth of large-scale and high quality SnS2 atomic layers and the investigation of their properties as a semiconductor.Here,we report the chemical vapor deposition (CVD) growth of atomic-layer SnS2 with a large crystal size and uniformity.In addition,the number of layers can be changed from a monolayer to few layers and to bulk by changing the growth time.Scanning transmission electron microscopy was used to analyze the atomic structure and demonstrate the 2H stacking poly-type of different layers.The resultant SnS2 crystals is used as a photodetector with external quantum efficiency as high as 150％,suggesting promise for optoelectronic applications.