技术应用型本科院校大学物理实验的模块式教学探讨

本文分析了目前技术应用型本科院校大学物理实验开设实验的现状,提出了根据专业对象不同,采取模块式教学方式,从而达到物理实验教学为专业基础实验课及专业实验课教学服务的目的。     

Biomass fly ash deposition in an entrained flow reactor

Fly ash deposition on boiler surfaces is a major operational problem encountered in biomass-fired boilers. Understanding deposit formation, and developing modelling tools, will allow improvements in boiler efficiency and availability. In this study, deposit formation of a model biomass ash species (K₂Si₄O₉) on steel tubes, was investigated in a lab-scale Entrained Flow Reactor. K₂Si₄O₉ was injected into the reactor, to form deposits on an air-cooled probe, simulating deposit formation on superheater tubes in boilers. The influence of flue gas temperature (589 – 968°C), probe surface temperature (300 – 550°C), flue gas velocity (0.7 – 3.5?m/s), fly ash flux (10,000 – 40,000?g/m²h), and probe residence time (up to 60?min) was investigated. The results revealed that increasing flue gas temperature and probe surface temperature increased the sticking probability of the fly ash particles, thereby increasing the rate of deposit formation. However, increasing flue gas velocity resulted in a decrease in the deposit formation rate, due to increased particle rebound. Furthermore, the deposit formation rate increased with probe residence time and fly ash flux. Inertial impaction was the primary mechanism of deposit formation, forming deposits only on the upstream side of the steel tube. A mechanistic model was developed for predicting deposit formation in the reactor. Deposit formation by thermophoresis and inertial impaction was incorporated into the model, and the sticking probability of the ash particles was estimated by accounting for energy dissipation due to particle deformation. The model reasonably predicted the influence of flue gas temperature and fly ash flux on the deposit formation rate.     

中药穴位贴敷联合耳穴贴压对急性化脓性阑尾炎术后胃肠功能的影响

目的 探讨中药穴位贴敷联合耳穴贴压对急性化脓性阑尾炎术后患者胃肠功能的影响。方法 选取我院2017年11月~2019年12月急诊行阑尾切除术后的80例患者,通过随机数字表法分为两组,各40例。对照组采取术后常规护理干预,治疗组在对照组术后常规护理干预基础上采取中药穴位贴敷及耳穴贴压。观察两组患者术后肠鸣音恢复时间、肛门首次排气时间和排便时间。结果 治疗组术后肠鸣音恢复时间、肛门首次排气排便时间均短于对照组,差异明显（P<0.05）;治疗组术后12、24、48 h腹胀发生率均低于对照组,差异有统计学意义（P<0.05）。结论 联合采取中药穴位贴敷及耳穴贴压治疗能有效促进急性化脓性阑尾炎术后患者胃肠功能的恢复,减少并发症的发生,加快康复进程,具有一定的临床价值。     

基于冷门预判断的P2SP点播系统片选策略的设计与实现

结合视频点播应用中对于提高点播质量和减轻服务器负担的要求,设计和实现了一个融合P2P和P2S网络的点播系统xBT。分析现有的BitTorrent协议应用于点播系统的局限性,针对点播过程中存在冷门片段的特点,对BitTorrent协议的片段选择策略提出改进。试验分析表明,xBT在大并发量的点播系统中能够提高用户的播放质量,同时减少服务器压力。     

铁素体不锈钢高温氧化层生长及热轧粘辊研究

通过高温氧化实验研究了超纯21%Cr铁素体不锈钢高温氧化层的生长情况,并采用开发的模拟铁素体不锈钢热轧粘辊实验方法研究了表面氧化对超纯21%Cr铁素体不锈钢热轧粘辊的影响,探讨了铁素体不锈钢的热轧粘辊机理.实验发现:超纯21%Cr铁素体不锈钢的炉生氧化铁皮较厚,而热轧过程中二次氧化铁皮生长较缓慢;锤头在循环轧制过程中出现的表面裂纹为热轧粘辊提供了形核地点;在高温变形过程中,表面氧化对铁素体不锈钢带钢表面具有保护作用,可以减轻热轧粘辊.     

磁悬浮列车轨道梁机加工

以磁悬浮列车轨道梁为对象研究超大型构件的定位及加工技术.超大型构件由于其自重和体积大难以采用传统的定位方法进行定位加工,只能在进行粗略的放置和固定后,用机床来找正工件的位置,实现“粗调位置-找正拟合定位-建模-加工”的过程.采用群控(DNC)控制技术有效解决了远距离实时数据传递与控制问题,避免了人为误差,提高了系统的可靠性.用瞄准镜作为机加工前的定位测量,设计相应的拟合算法,求出轨道梁相对于机床的加工位置,根据测量拟合的数据建立轨道梁机加工模型,使得加工余量均匀,确保了加工节拍.     

古陶,瓷文物属性的计算机鉴定

古陶,瓷文物的属性很复杂,内容十分丰富。本文只研究以穆斯堡尔谱为基础的古陶片最高烧结温度与其绝对年令属性的计算机鉴定方法,以及用古瓷釉/胎原料的中子活化分析微量元素特征谱作根据的古瓷瓷类,窑址和时代属性的计算机鉴定原理。     

渤中34-1N钻井帽在锦州9-3油田井口平台上的应用

渤中34-1N钻井帽始建于2009年,计划在渤中34-1N油田利用其与非悬臂式钻井船(渤海5号)在导管架上方进行钻完井作业。但在钻井帽建造后期,悬臂式钻井船的紧张局面得到缓解,钻井帽被放置于建造场地4年。鉴于锦州9-3油田综合调整项目新建1座四腿井口平台,初步考虑利用钻井帽在锦州9-3油田井口平台的导管架上进行钻完井作业。因此,需要对钻井帽进行适应性改造。     

Measuring sticking and stripping in muon-catalyzed dt fusion with multilayer thin films

We propose a direct measurement of muon sticking to alpha particles in muon-catalyzed dt fusion at a high density. Exploiting the features of a multilayer thin-film target developed at TRIUMF, the sticking is determined directly by detection of charged fusion products. Experimental separation of initial sticking and stripping may become possible for the first time. Monte Carlo simulations, as well as preliminary results of test measurements are described.     

对铸铁件铸入钢管防渗碳效果的实验研究

本文通过生产实践总结了铸铁件铸入钢管防渗碳的效果与铸入检测试样中钢管防渗碳效果之差别。从而得出因铸件重量不同而引起防渗碳效果不同的规律。所得结果可用于冷却壁的设计、检验。并可为用户选用产品提供依据。