摘要：For low power dielectric barrier discharge （DBD） used in small-size material treatment or portable devices, high- step transformer parasitic capacitance greatly influences the performance of the resonant converter as it is of the same order of magnitude as the equivalent capacitance of DBD load. In this paper, steady-state analysis of the low power DBD is presented, considering the inevitable parasitic capacitance of the high-step transformer. The rectifier-compensated first harmonic approxi- mation （RCFHA） is applied to linearize the equivalent load circuit of DBD at low frequency and the derived expressions are accurate and convenient for the analysis and design of the power supply. Based on the proposed linear equivalent load circuit, the influence of transformer parasitic capacitance on the key parameters, including the frequency range and the applied electrode voltage, is discussed when the power is regulated with pulse frequency modulation （PFM）. Also, a design procedure is presented based on the derived expressions. A prototype is constructed according to the design results and the accuracy of the design is verified by experimental results.

摘要：The proper choice of optomechanical components along with alignment techniques is vital to the successful implementation of lens positioning and mounting. In general, there is a trade-off between lens positioning accuracy and manufacturing cost. In order to achieve optimal precision- to-cost ratio, a careful optomechanical design together with accurate alignment and assembly is necessary. This paper presents a lens positioning and mounting in a few microns accuracy using a kinematic mount module. The optomechanical design of the kinematic mount module and the associated fixtures based on the simulation study of components sensitivity are presented. The processes for alignment and assembly, which separate decenter from tip-tilt, are developed and presented. Finally, the prototypes are created and testing results are presented. The optomechanical design that allows the separation of decenter from tip-tilt considerably simplifies the positioning and assembly process and reduces the cost for mass production.

摘要：Increasing attention has been paid to develop flexible integrated energy devices, but it remains a big challenge to achieve a common electrode for building both energy conversion and storage devices with high performance. Here, we for the first time selectively functionalize polyaniline(PANI) and platinum(Pt)inside different segments of chemical vapor deposition grown continuous graphene tube, achieving selectively functionalized graphene composite(PANI//Pt@G) fibers. The PANI@G and Pt@G parts could be used as efficient electrodes for supercapacitor with a specific capacitance of 284 m F cm-2 and dye-sensitized solar cell with a power conversion efficiency of 4.73%, respectively. By using a PANI//Pt@G fiber as the common electrode, an integrated energy device with a total energy conversion and storage efficiency of 3.07% is realized. The continuous graphene tubes could be functionalized with other active materials for other flexible and wearable electronics.

摘要：胡深,男,汉族,1931年生,陕西省凤翔县郊六营村人;凤翔泥塑资深匠人,首批国家级非物质文化遗产项目代表性传承人,中国工艺美术大师,中国艺术研究院特聘"民间艺术创作研究员"。其作品画风细腻、洒脱,构图与色彩层次分明,极富西府民俗特色。其中《泥塑马》《泥塑羊》分别于2002年、2003年入选国家邮政局生肖邮票图案。

摘要：通过分子动力学方法研究化学组分和温度对水化硅铝酸钙(C-A-S-H)凝胶结构和力学性能的影响规律,结合强度试验为超高温固井水泥砂铝配比提供试验指导。构建C-A-S-H凝胶模型,研究温度、Ca/Si、Al/Si对硅氧四面体结构Q n分布、平均链长的影响规律。通过C-A-S-H凝胶断裂过程的应力应变关系,结合Al、Si原子平均受力特征,揭示富铝相C-A-S-H的增强机制。结果表明:Al的加入能够有效填补硅氧链桥位缺陷,增加平均链长,增强桥联层间硅氧结构,促进形成聚合度更高的硅氧四面体,进而提升强度;超高温220~260℃时,Ca、Si、Al物质的量比为0.9∶1∶0.15~0.2,对应加砂55%、铝质材料7%~10%BWOC,可满足固井水泥强度要求。

摘要：围绕相关低空概念以及不同类别低空载人航空器特性,通过分析国内外相关经验,深入探究浦东新区低空发展现状;同时,依据浦东新区特点和发展需求,考虑应用场景,并基于多维度应用场景提出航空器起降点的布局规划,以保障低空载人航空器安全高效运行。研究结果可为浦东新区低空载人航空器起降点布局提供具有针对性和可操作性的思路,这对促进浦东新区低空领域发展、完善相关基础设施规划具有重要意义,同时也可为其他类似地区的低空起降点布局规划提供了参考。

摘要：水电站工程安全监测仪器服役时长和时变特性,是影响工程安全监测设计、实施和运行管理的核心因素之一,然而国内外却鲜有对于安全监测仪器服役时变规律的研究。收集了我国10个水电站工程安全监测仪器服役表现的实际大样本数据,总结其重要时间节点,统计其监测仪器总失效率,揭示了安全监测仪器失效率的时变规律。结果表明:①施工期,7个工程监测仪器失效率增量模型符合正态函数,6个工程监测仪器失效率增量先增后减,拐点出现在施工期的51%~84%处;3个工程失效率持续上升。②运行期,工程监测仪器失效率均呈平稳上升趋势,符合线性模型。提出的安全监测仪器服役时变模型均能有效预估各工程安全监测仪器失效率变化情况。

摘要：在全球可持续生态城市建设浪潮中,北京以“和谐宜居之都”为目标,基于生态安全格局制定《北京城市总体规划(2016—2035)》,并在中心城区实施了一系列生态基础设施改造项目。本研究基于生态都市主义理论,指出这些城市更新实践是联系城市绿色愿景与个人日常行为的关键。本文构建了一个包含环境生态、社会生态和心理生态三个维度的理论框架,并设定了生态更新实践的三重评价要点:修复生态基础设施、激活社区、重建社会-环境共生关系。本文据此评估北京首钢工业遗址公园项目的城市更新过程,发现其中有机会构建景观与公众参与活动、市民环保行动的关联。本文提出改进的实践模式——“协作式生态更新”,强调结合中尺度景观更新与市民参与,并提供包含三个维度上设计策略的适应性工具包,在修复中小尺度生态基础设施的同时,可形成包容性社会协作平台并提升个人环境意识。其中的关键工具“城市原型”既能联系不同维度上的策略,又可将实践经验概念化,进而应用于构建新策略。作为示范,本文将之应用于北京中心城区实践,展示出这种新的实践模式的开放式城市更新过程,在适应不同城市条件与利益相关者需求的过程中形成新的城市原型,可有助于逐步构建北京的绿色未来。

摘要：量子点发光二极管(QLED)是不需要额外光源的主动发光技术,在显示领域中的应用前景被广泛看好。寿命较短是影响QLED商业化的重要因素之一,并且其老化机理尚不清晰。在本工作中,我们通过自主搭建电荷提取装置,证实红光QLED在恒流驱动过程中,存在显著的电荷累积。累积电荷量随着驱动电流密度增加而增加,但当超过阈值电流密度(对应于开启电压)后逐渐趋于饱和。随着器件老化,亮度下降伴随着累积电荷量进一步增加。本工作对QLED老化过程中电荷累积规律的理解,能为QLED材料和界面的优化设计提供直观判据。

摘要：针对铁路400 MHz数字无线列调系统试验过程中信道切换时遇到的问题,研究切换信道时车载侧和地面侧信道机的处理机制,分析试验中遇到的问题,研究车载侧信道机改进处理机制以及如何利用现有的协议改进处理机制,通过现场试验,验证改进的处理机制对于信道切换时遇到问题的解决情况。