Spark plasma sintering of UO2 nanopowders: Pressure,heating rate and current effects

We analysed with different methods the densification of UO₂ nanopowders in SPS under constant heating rate (CHR) and isothermal sintering conditions. The apparent activation energy of densification in SPS (75 kJ/mol with CHR method) is significantly smaller than in conventional sintering. It is shown that this is likely not an effect of the applied current. We also observed a threshold stress at 64 MPa for the transition from pressure-insensitive sintering (stress exponent n≈0) to pressure-assisted sintering, suggesting that the contribution of the capillary stresses in such nanopowders is comparable with the typical stress applied in SPS.     

Artistic Augmentation of Photographs with Droplets

Journal of Computer Science and Technology - Artistic augmentation of photographs with water droplets aims at generating aesthetic yet realistic images, and thus differs from traditional augmented...     

AppFusion: Interactive Appearance Acquisition Using a Kinect Sensor

We present an interactive material acquisition system for average users to capture the spatially varying appearance of daily objects. While an object is being scanned, our system estimates its appearance on‐the‐fly and provides quick visual feedback. We build the system entirely on low‐end, off‐the‐shelf components: a Kinect sensor, a mirror ball and printed markers. We exploit the Kinect infra‐red emitter/receiver, originally designed for depth computation, as an active hand‐held reflectometer, to segment the object into clusters of similar specular materials and estimate the roughness parameters of BRDFs simultaneously. Next, the diffuse albedo and specular intensity of the spatially varying materials are rapidly computed in an inverse rendering framework, using data from the Kinect RGB camera. We demonstrate captured results of a range of materials, and physically validate our system.     

一款紧凑增强型可变阻抗电磁带隙结构

基于传统AI-EBG结构,提出了一种小尺寸的增强型电磁带隙结构,实现了从0.5~9.4 GHz的宽频带-40 dB噪声抑制深度,且下截止频率减少到数百MHz,可有效抑制多层PCB板间地弹噪声。文中同时研究了EBG结构在高速电路应用时的信号完整性问题,使用差分信号方案可改善信号完整性。     

Feature-based ontological framework for semantic interoperability in product development

An essential requirement in integrating tasks in product development is to have a seamless exchange of product information through the entire product lifecycle. A key challenge in the integration is the exchange of shape semantics in terms of understandable labels and representations. A unified taxonomy is proposed to represent, classify, and extract shape features. This taxonomy is built using the Domain-Independent Form Feature (DIFF) model as the representation of features. All the shape features in a product model are classified under three main classes, namely, volumetric features, deformation features and free-form surface features. Shape feature ontology is developed using the unified taxonomy, which brings the shape features under a single reasoning framework. One-to-many reasoning framework is presented for mapping semantically equivalent information (label and representation) of the feature to be exchanged to target applications, and the reconstruction of the shape model automatically in that target application. An algorithm has been developed to extract the semantics of shape features and construct the model in the target application. The algorithm developed has been tested for shape models taken from literature and test cases are selected based on variations of topology and geometry. Results of exchanging product information are presented and discussed. Finally, the limitations of the proposed method for exchanging product information are explained.     

O-羧甲基壳聚糖在柠檬酸水溶液中的聚合工艺

利用O-羧甲基壳聚糖同时具有羧基、羟基和氨基等活性基团的特点,用柠檬酸为交联剂,可以使其发生聚合反应,生成不溶于水的高分子聚合物。通过对聚合产物产率的测算与分析,探讨了O-羧甲基壳聚糖在柠檬酸水溶液中的交联工艺参数对聚合物产率的影响。通过一系列单因素和正交试验,确定了最佳聚合工艺条件为:O-羧甲基壳聚糖溶液质量浓度为20 g/L,柠檬酸溶液质量浓度为40 g/L,反应pH值为6.0,反应温度为25℃,反应时间为10 min。     

中空载银纤维的银离子释放性能

银系纤维的抗菌性能主要来源于纤维表面或内部释放出来的银离子。采用电感耦合等离子体发射光谱仪对中空载银纤维的银离子释放性能进行测试分析,结果表明:中空载银纤维具有较为持久的释放性能,释放的银离子量随着浸渍时间的延长、浸渍温度的升高以及纤维本身载银量的增加而增加,随着纤维长度的增加而减少。     

Object-Oriented Approach in Design for Lift Installation of Offshore Structures

Abstract: A consistent representation of offshore structures and barges that is appropriate for computer processing is essential for the development of an efficient design system for offshore heavy lift installation. This paper outlines the representation of conceptual and physical entities in the preliminary design for lift installation through an object-oriented approach. The spatial and topologic abstractions of physical entities are illustrated. These abstractions, together with the locational dependency concept for an assembly, form the backbone for geometric reasoning in the top-down approach for lift installation design. An object-oriented prototype system for lift evaluation, C-LIFT, using the knowledge-based development tool kit ART_*Enterprise is described. A liftability study involving the installation of offshore modules and the associated lift sequence is then presented to illustrate the advantages of this approach.