钢筋混凝土结构CAD应用软件研究

本文着重对廓道配筋ＣＡＤ研究中的钢筋绘制、钢筋尺寸标注、钢筋表的自动生成等进行了深入的探讨。并针对空间复杂相交体几何建模的特殊性应用坐标传递法。对廓道进行了几何计算。同时，对廓道等径相交处基于反映实形的展视图画法提供了一种表达方式。     

High resolution angular-displacement sensor based on whispering gallery mode resonance in bent optical fibers

A simple fiber sensor to measure angular displacement with high resolution,which is based on whispering gallery mode(WGM)resonance in bent optical fibers,is proposed.The sensor is composed of a single loop formed by loosely tying a knot using single mode fiber.To measure the transmission spectra,a tunable laser and an optic power meter are connected to the two ends of fiber loop,respectively.Significant WGM resonances occur over the investigated wavelength range for all the sensors with different bend radius.The angular-displacement sensitivity is studied in the range from-0.1°to 0.1°.The detection limit of1.49×10-7 rad can be achieved for the detecting system with the resolution of 1pm.The simple loopstructure fiber sensor has potential application prospect in the field of architecture or bridge building with low detection limit and low cost.     

粮仓地槽通风新型空气分配器的研究

本文以流体力学理论为依据,对习惯使用的空气分配器进行研究改进,解决了老式地槽通风空气分配器开孔率低、空气射流角偏小、分配器附近粮堆空气损失过大等问题。新研制的空气分配器采用双层空腔,形成缓衡空间,提高了气流射流角,降低了分配器附近粮堆内空气阻力,提高了开孔率,使粮堆静压均衡层提前出现,具有均匀送风性能,并获得明显的通风降温降水效果。     

Highly Efficient Triplet-Triplet-Annihilation Upconversion Sensitized by a Thermally Activated Delayed Fluorescence Molecule in Optical Microcavities

Triplet-triplet-annihilation (TTA) upconversion sensitized by a new thermally activated delayed fluorescence (TADF) molecule, BTZ-DMAC-4Br, is investigated in whispering gallery mode (WGM) microcavities made of toluene solutions filled into quartz capillaries. Since the utilization of the excitation light is improved in WGM microcavities through total internal reflection, the upconversion efficiency is enhanced greatly and an upconversion quantum yield of 24.6% is observed, which is a dozen times higher than that measured in conventional cuvettes. To the best of knowledge, this is the highest upconversion efficiency achieved in TADF sensitized TTA systems. Not only is a new material designed, but also the results provide a novel way to improve the TTA upconversion performance by utilizing the optical cavity effect, and the TTA microcavities may be used to construct highly efficient and low-threshold photonic devices in many applications.     

Coreless Fiber‐Based Whispering‐Gallery‐Mode Assisted Lasing from Colloidal Quantum Well Solids

Whispering gallery mode (WGM) resonators are shown to hold great promise to achieve high‐performance lasing using colloidal semiconductor nanocrystals (NCs) in solution phase. However, the low packing density of such colloidal gain media in the solution phase results in increased lasing thresholds and poor lasing stability in these WGM lasers. To address these issues, here optical gain in colloidal quantum wells (CQWs) is proposed and shown in the form of high‐density close‐packed solid films constructed around a coreless fiber incorporating the resulting whispering gallery modes to induce gain and waveguiding modes of the fiber to funnel and collect light. In this work, a practical method is presented to produce the first CQW‐WGM laser using an optical fiber as the WGM cavity platform operating at low thresholds of ≈188 µJ cm^?2 and ≈1.39 mJ cm^?2 under one‐ and two‐photon absorption pumped, respectively, accompanied with a record low waveguide loss coefficient of ≈7 cm^?1 and a high net modal gain coefficient of ≈485 cm^?1. The spectral characteristics of the proposed CQW‐WGM resonator are supported with a numerical model of full electromagnetic solution. This unique CQW‐WGM cavity architecture offers new opportunities to achieve simple high‐performance optical resonators for colloidal lasers.     

大古水电站坝前排沙运行方式与排沙漏斗形态

为给实际工程排沙设施的设计和布置提供依据,基于1∶60整体模型,根据淤积泥沙扬动流速相似原理,试验研究大古水电站2条排沙廊道和1个底孔在不同运行方式下坝前库区的排沙效果和排沙漏斗形态。结果表明:排沙洞开启顺序对最终排沙效果影响不大;深水条件下,坝前排沙漏斗形态主要受泥沙特性决定,非黏性沙的排沙漏斗坡度接近于淤积泥沙水下休止角;大古水电站排沙设施的设计方案具备保证电站进水口"门前清"的条件。     

城市综合管廊WSN中LEACH-HC协议的仿真研究

城市综合管廊是未来城市发展的重要基础设施之一.具有截面小,延伸距离长的特点.为了适应管廊的这种特殊环境,进行有效监测.对无线传感网络在管廊中的应用做了深入研究.针对LEACH协议的节点布局和簇头选举方面进行改进,提出LEACH-HC协议,以适应管廊的工作要求.通过MATLAB仿真工具与经典LEACH、SEP进行对比实验.结果表明LEACH-HC协议不仅能满足综合管廊的需求,且具有较好的生存能力.     

基于移动感知的综合管廊电缆线路运行状态诊断系统设计及应用北大核心CSCD

综合管廊是雄安新区城市管网主要方式,运行环境复杂,随着其运检数量的指数级增长,状态数据离散化、孤岛化严重,依靠人力为主的传统运检模式已无法支撑电网的运维需求。为此,文中设计了一种新型基于移动感知的综合管廊电力舱电缆线路的运行状态诊断系统,利用小波分解对感知数据进行压缩,并根据前、后端数据特征及应用场景进行算法设计,形成了一套基于前端短时数据的电缆线路状态分析预测及大数据后台的多维度融合分析与决策系统,综合实现设备识别、状态感知、数据交互与智能诊断的无缝衔接和多层级电缆运行可靠性评价。该系统在应用中能够成功确立电缆线路缺陷因素等级,发现同类风险隐患,并给出检修建议,进一步强化了设备状态管控力、优化设备运维策略。     

Pose Robust Low-resolution Face Recognition via Coupled Kernel-based Enhanced Discriminant Analysis

Most face recognition techniques have been successful in dealing with high-resolution (HR) frontal face images. However, real-world face recognition systems are often confronted with the low-resolution (LR) face images with pose and illumination variations. This is a very challenging issue, especially under the constraint of using only a single gallery image per person. To address the problem, we propose a novel approach called coupled kernel-based enhanced discriminant analysis (CKEDA). CKEDA aims to simultaneously project the features from LR non-frontal probe images and HR frontal gallery ones into a common space where discrimination property is maximized. There are four advantages of the proposed approach: 1) by using the appropriate kernel function, the data becomes linearly separable, which is beneficial for recognition; 2) inspired by linear discriminant analysis (LDA), we integrate multiple discriminant factors into our objective function to enhance the discrimination property; 3) we use the gallery extended trick to improve the recognition performance for a single gallery image per person problem; 4) our approach can address the problem of matching LR non-frontal probe images with HR frontal gallery images, which is difficult for most existing face recognition techniques. Experimental evaluation on the multi-PIE dataset signifies highly competitive performance of our algorithm.      

海南省陀兴水库浆砌石重力坝改扩建方案研究

陀兴水库建于20世纪六七十年代,由于当时设计和施工条件有限,经过多年运行后年久失修,需将浆砌石重力坝加高培厚。根据坝址区地质勘探资料及坝体钻孔揭露情况,拟定了三种改扩建方案。为了确保工程扩建后的正常运行,从渗透稳定性、结构安全性、抗滑稳定性和工程投资等多个方面进行了对比论证,以便为工程的顺利实施提供参考。