基于热化学沉积的快速成形系统的研究与开发

快速成形技术与化学沉积技术的集成,促生了新的快速成形工艺.提出了基于热化学沉积的快速成形工艺,分析了工艺的基本原理和技术特点,设计并建立了基于热化学沉积的快速成形系统.工艺试验证明,该系统成功实现了工艺过程,工作稳定可靠,为工艺研究和应用提供了必备的基础.     

Fine Multi‐Phase Alignments in 2D Perovskite Solar Cells with Efficiency over 17% via Slow Post‐Annealing

Layered Ruddlesden–Popper (RP) phase (2D) halide perovskites have attracted tremendous attention due to the wide tunability on their optoelectronic properties and excellent robustness in photovoltaic devices. However, charge extraction/transport and ultimate power conversion efficiency (PCE) in 2D perovskite solar cells (PSCs) are still limited by the non‐eliminable quantum well effect. Here, a slow post‐annealing (SPA) process is proposed for BA₂MA₃Pb₄I₁₃ (n = 4) 2D PSCs by which a champion PCE of 17.26% is achieved with simultaneously enhanced open‐circuit voltage, short‐circuit current, and fill factor. Investigation with optical spectroscopy coupled with structural analyses indicates that enhanced crystal orientation and favorable alignment on the multiple perovskite phases (from the 2D phase near bottom to quasi‐3D phase near top regions) is obtained with SPA treatment, which promotes carrier transport/extraction and suppresses Shockley–Read–Hall charge recombination in the solar cell. As far as it is known, the reported PCE is so far the highest efficiency in RP phase 2D PSCs based on butylamine (BA) spacers (n = 4). The SPA‐processed devices exhibit a satisfactory stability with <4.5% degradation after 2000 h under N₂ environment without encapsulation. The demonstrated process strategy offers a promising route to push forward the performance in 2D PSCs toward realistic photovoltaic applications.     

多胺同植物代谢及果品贮藏保鲜的关系

多胺是生物体代谢过程中产生的具有生物活性的低分子量脂肪族含氮碱，多胺同植物代谢及贮藏保鲜的关系问题已经成为近年来研究的热点之一。本文综述了多胺与植物生长发育，多胺与植物体抗性，多胺的测定方法，多胺与果实采后生理和贮藏保鲜的关系，旨在为多胺在果实采后生理领域的研究和应用提供理论依据。     

From high hopes to high deficit and back: A historic overview of Europe’s HDTV policy and reflections towards the future of HDTV

This paper describes the standardisation process and introduction timeline of high definition television. The development of the standard is a process that goes back over 40 years, but HDTV is only today slowly finding its place in the home entertainment market. This paper explores why the European standard for analogue HDTV was not widely adopted, what Europe’s relation to HDTV means today, and proposes some general lessons that can be learned for the benefit of the development of HDTV’s successor, Ultra HDTV aka Super Hi-Vision.     

G.657 A2光纤在干线中的应用

在对比ITU-TG.657 A2与G.652 D光纤标准的基础上,介绍了G.657 A2光纤的设计和主要性能参数,对G.657 A2与G.652 D光纤的兼容性及性能进行了对比分析,并结合对易贝G.657 A2光纤的多径干扰（MPI）测试和系统传输实验,阐述了G.657 A2在干线中应用的优势及应用前景。     

DVD光学头的BP神经网络自适应PID控制器设计

搭建了一套基于DVD聚焦循道伺服技术和双光子吸收三维光存储技术的双光头三维光盘存储系统.针对DVD光学读取头传递函数,采用BP神经网络自适应PID控制算法,构建PID控制系统仿真模型,通过BP神经网络的超强自学习和非线性逼近能力在线调整PID控制器参数,并进行计算机Matlab仿真.仿真结果表明,BP神经网络自适应PID控制算法提升了系统的响应速度,减小了系统的超调量.     

Retinal Ciliopathy in the Patient with Transplanted Kidney: Case Report

A review of a rare case of a proven mutation in the RP1 gene (RP1c.2029C>T, p. (ARG677*) in a kidney transplant patient was presented herein. According to his medical history, he had tonsillectomy performed at the age of 20 due to erythrocyturia, and at the age of 32 he was treated for malignant hypertension. The patient had been diagnosed with chronic renal failure at age 56 years. During an eye examination in 2016, retinitis pigmentosa was suspected and the patient was advised to run further tests. After an ophthalmological examination and tests, genetic testing was performed and a mutation in the RP1 gene encoding a family of proteins which are components of microtubules in photoreceptor primary cilia was proven. The literature search found that mutations in the RP1 gene have so far been exclusively associated with a non-syndromic form of retinal degeneration. However, the RP1 protein is expressed in the kidneys, and it remains unclear why the mutation of this gene so far was only specifically related to retinal photoreceptor function and not to arterial hypertension and renal disease. Primary cilia are thought to act as potential mechanosensory fluid-flow receptors in the vascular endothelium and kidney and their dysfunction results in atherosclerotic changes, hypertension, and chronic renal failure.     

联邦卡尔曼滤波器在无人机导航系统中的应用

针对无人机GPS／RP／DR组合导航系统的特点，设计了用于该系统的联邦卡尔曼滤波器。该滤波器具有全局最优性，其结构遵循信息分配原则，其算法改善了数值计算的稳定性和系统的容错性，并减少了信息传输量与计算量。理论分析及仿真结果表明，该联邦卡尔曼滤波器能够满足无人机在GPS或RP信号无效或两信号均短期无效情况下定位导航的精度要求。     

降低可复用软件构件开发难度的适配器机制

许多软件开发机构通过利用能够适应不同产品和环境需求的多用途构件组织软件生产线来支持软件复用的思想。为了更好地支持可重用构件的设计和实现,提出了构件交互适配器这一思想。适配器机制可用来定制、联接和管理可重用构件的交互作用。而且,通过使用适配器机制,可将构件的交互作用屏蔽于构件内部实现细节之外进行管理,这就能有效地降低开发构件的复杂性,提高可复用性并易于构件的实现。     

面部动态特征描述的抑郁症识别

目的 抑郁症是一种严重的精神类障碍,会显著影响患者的日常生活和工作。目前的抑郁症临床评估方法几乎都依赖于临床访谈或问卷调查,缺少系统有效地挖掘与抑郁症密切相关模式信息的手段。为了有效帮助临床医生诊断患者的抑郁症严重程度,情感计算领域涌现出越来越多的方法进行自动化的抑郁症识别。为了有效挖掘和编码人们面部含有的具有鉴别力的情感信息,本文提出了一种基于动态面部特征和稀疏编码的抑郁症自动识别框架。方法 在面部特征提取方面,提出了一种新的可以深层次挖掘面部宏观和微观结构信息的动态特征描述符,即中值鲁棒局部二值模式—3D正交平面（median robust local binary patterns from three orthogonal planes,MRELBP-TOP）。由于MRELBP-TOP帧级特征的维度较高,且含有部分冗余信息。为了进一步去除冗余信息和保留关键信息,采用随机映射（random projection,RP）对帧级特征MRELBP-TOP进行降维。此外,为了进一步表征经过降维后的高层模式信息,采用稀疏编码（sparse coding,SC）来抽象紧凑的特征表示。最后,采用支持向量机进行抑郁程度的估计,即预测贝克抑郁分数（the Beck depression inventory-II,BDI-II）。结果 在AVEC2013（the continuous audiovisual emotion and depression 2013）和AVEC2014测试集上,抑郁程度估计值与真实值之间的均方根误差（root mean square error,RMSE）分别为9.70和9.22,相比基准算法,识别精度分别提高了29%和15%。实验结果表明,本文方法优于当前大多数基于视频的抑郁症识别方法。结论 本文构建了基于面部表情的抑郁症识别框架,实现了抑郁程度的有效估计;提出了帧级特征描述子MRELBP-TOP,有效提高了抑郁症识别的精度。