丙烯酸酯乳液聚合稳定性的研究

本文对丙烯酸酯乳液的聚合稳定性进行了研究,讨论了乳化剂用量、配比、引发剂用量及功能单体对聚合稳定性的影响。     

Thermodynamic Properties and Molecular Packing Explain Performance and Processing Procedures of Three D18:NFA Organic Solar Cells

Organic solar cells (OSCs) based on D18:Y6 have recently exhibited a record power conversion efficiency of over 18%. The initial work is extended and the device performance of D18-based OSCs is compared with three non-fullerene acceptors, Y6, IT-4F, and IEICO-4Cl, and their molecular packing characteristics and miscibility are studied. The D18 polymer shows unusually strong chain extension and excellent backbone ordering in all films, which likely contributes to the excellent hole-transporting properties. Thermodynamic characterization indicates a room-temperature miscibility for D18:Y6 and D18:IT-4F near the percolation threshold. This corresponds to an ideal quench depth and explains the use of solvent vapor annealing rather than thermal annealing. In contrast, D18:IEICO-4Cl is a low-miscibility system with a deep quench depth during casting and poor morphology control and low performance. A failure of ternary blends with PC₇₁BM is likely due to the near-ideal miscibility of Y6 to begin with and indicates that strategies for developing successful ternary or quaternary solar cells are likely very different for D18 than for other high-performing donors. This work reveals several unique property–performance relations of D18-based photovoltaic devices and helps guide design or fabrication of yet higher efficiency OSCs.     

可持续发展度解构——岭南汉民系乡村聚落生命源动力的探寻

研究课题探寻岭南汉民系乡村聚落人居环境构成的基本要素与平衡关系。在梳理研究方面,将聚落人居环境构成特征力求以定性定量参数的形式予以分解表达,具体体现在场地与土地利用、能源与资源配置、文化特征、建筑功能与格局、聚落健康与舒适和聚落经济活动六大方面,从而推演出聚落在面向未来发展时各基本面的优劣条件;提炼研究方面,将以“可持续发展度”这一综合指标,把不同形态、不同发展水平聚落的六大方面各项参数拟合为单一、可追踪、可比较的定性结论,从而为岭南汉民系乡村聚落整体低碳更新的政策制定和改造实施提供具有实践指导意义、简洁直观的评价标准。     

基于模糊理论的导弹系统贮存可靠性仿真方法研究

针对新型、复杂导弹系统的贮存可靠性分析困难的问题,研究了模糊故障树分析法和模糊系统贮存可靠性仿真方法,探讨了将导弹系统视为模糊系统,基于模糊理论对其贮存可靠性进行研究的思路,为新型、复杂导弹系统贮存可靠性的研究提供了技术途径。以某型号导弹自动驾驶仪为例,在功能分析的基础上建立了自动驾驶仪模糊故障树,然后利用模糊系统贮存可靠性仿真方法对其贮存可靠性指标进行了分析。     

粒状土与结构接触面多重剪切边界面模型

针对工程中存在大量的土与结构物相互作用,使接触面的力学特性对土体和结构物的受力变形及其相互作用产生重要影响的问题,利用塑性滑移理论,将粗粒土与结构接触面的宏观变形分解为一个宏观法向变形和剪切面内一系列不同方向分布的相互独立虚拟微观剪切变形;通过虚功原理,在粒状土的状态相关和边界面弹塑性理论框架内建立一个粗粒土与结构接触面的多重剪切边界面模型.每个微观剪切变形包含一个微观剪应力-应变关系和一个微观应力-剪胀关系.引入一个与接触面土体密度和法向应力相关的状态参数,用以描述不同状态下土与结构接触面的变形和强度特性.对不同粗粒土与结构接触面在二维或三维应力条件下的单调和循环剪切试验进行模拟计算,模型预测与试验结果吻合良好,说明模型能够合理地描述粗粒土与结构接触面的非线性力学行为.     

基于模糊理论的导弹系统贮存可靠性仿真方法研究

针对新型、复杂导弹系统的贮存可靠性分析困难的问题,研究了模糊故障树分析法和模糊系统贮存可靠性仿真方法,探讨了将导弹系统视为模糊系统,基于模糊理论对其贮存可靠性进行研究的思路,为新型、复杂导弹系统贮存可靠性的研究提供了技术途径.以某型号导弹自动驾驶仪为例,在功能分析的基础上建立了自动驾驶仪模糊故障树,然后利用模糊系统贮存可靠性仿真方法对其贮存可靠性指标进行了分析,对自动驾驶仪的维护与管理具有指导作用.     

Multifluid model simulations of gravitational instabilities in fluidized binary granular materials

Predicting granular flow using continuum approaches is fundamental to advance granular physics and industrial applications. Previous studies have demonstrated that continuum modeling can capture some hydrodynamic instability analogs in monodisperse granular materials. Recently, a family of gravitational instabilities was found between two types of grains, including a Rayleigh–Taylor analog, a granular bubble rising, a granular droplet splitting and particle segregation. The high packing fraction and bi-disperse nature of these flows allow for new challenges to continuum models. Herein, we applied multifluid modeling (MFM) that treats the gas phase and two separate granular phases as fully interpenetrating continua to simulate these instabilities and compared them with newly conducted experiments. Simulation results reproduced all of the four instabilities and demonstrated that frictional particle stress and solids–solids drag are needed to capture critical qualitative flow features. This study can serve as a basis for challenging future particle stress and solids–solids drag models.     

超细WC／Co粉末及其烧结体的制备与表征

以水合肼为还原剂,于液相中制得超细we／co硬质合金包覆粉,后处理并进行低压烧结,制得力学性能良好的WC／Co硬质合金烧结体。考察了反应体系温度对反应时间的影响,搅拌速度对包覆率的影响,采用SEM、TEM、EDS等手段对包覆粉进行了表征;对比了不同规格、不同烧结方法对WC／Co烧结体力学性能的影响,采用金相、被散等照片对烧结体进行表征,并最终确定了制备WC／CO包覆粉及其烧结体的优化工艺条件。结果表明：此方法制得的WC／Co包覆粉纯度高,粒径均匀,低压烧结后所得烧结体力学性能良好。