涡轮端壁平均气膜冷却效率的正交模拟研究

在涡轮叶栅端壁21%、51%、81%轴向弦长处和距前缘9%轴向弦长端壁处布置4排圆柱形气膜冷却孔,运用CFD方法模拟吹风比、轴向倾角α和展向倾角β3个影响因素共同作用下的端壁平均气膜冷却效率,通过正交方案选出最优孔排布置方式.结果表明:吹风比对端壁平均气膜冷却效率的影响最大,展向倾角β影响次之,轴向倾角α影响最小;吹风比为2.0,轴向倾角α为30°,展向倾角β为45°(第1、第3排冷却孔与y轴负方向成45°,第2、第4排冷却孔与y轴正方向成45°)布置时,端壁表面平均气膜冷却效率最高,为3个因素影响下的最优方案.     

Plasmonic Nickel Nanoantennas

The fundamental optical properties of pure nickel nanostructures are studied by far‐field extinction spectroscopy and optical near‐field microscopy, providing direct experimental evidence of the existence of particle plasmon resonances predicted by theory. Experimental and calculated near‐field maps allow for unambiguous identification of dipolar plasmon modes. By comparing calculated near‐field and far‐field spectra, dramatic shifts are found between the near‐field and far‐field plasmon resonances, which are much stronger than in gold nanoantennas. Based on a simple damped harmonic oscillator model to describe plasmonic resonances, it is possible to explain these shifts as due to plasmon damping.     

阿勒泰羊臀脂及其分提产物对小鼠结肠形态及盲肠内容物短链脂肪酸影响

为研究阿勒泰羊臀脂及其溶剂法分提产物的营养特性,选取60只昆明雄性小鼠,随机分为5组,使用2 ℃分提产物（2 ℃组）、12 ℃分提产物（12 ℃组）、原脂（BF组）、菜籽油（RO组）和生理盐水（CK组）进行灌胃（1.5 mL/10 g）,分别于第20和40 d处死小鼠并测量相关指标。结果表明:灌胃20 d后,除CK组外,各组小鼠盲肠中乙酸、丁酸和戊酸含量无显著性差异（P>0.05）,BF组盲肠丙酸含量、2和12 ℃组盲肠异戊酸含量显著高于RO组（P<0.05）,12 ℃和BF组小鼠结肠绒毛长度和结肠隐窝深度均显著低于RO组（P<0.05）。灌胃40 d后,2 ℃组盲肠丙酸、丁酸和戊酸及12 ℃组盲肠乙酸、丙酸和丁酸的含量显著高于RO组（P<0.05）,12 ℃和BF组结肠隐窝深度和绒毛长度显著低于RO组（P<0.05）。说明在此摄入水平下,阿勒泰羊臀脂2 ℃分提产物比原脂和菜籽油更有利于维持小鼠盲肠短链脂肪酸含量的相对稳定,并且对于结肠损伤较小。     

Kinetics of Lipid Oxidation and Degradation of Flaxseed Oil Containing Crawfish (<Emphasis Type="Italic">Procambarus clarkii</Emphasis>) Astaxanthin

Flaxseed oil (FO) containing crawfish (Procambarus clarkii) astaxanthin (FOA) was evaluated for lipid oxidation and astaxanthin degradation. The FOA was analyzed for astaxanthin content, free fatty acids (FFA), peroxide value (PV), fatty acid methyl esters (FAMEs) profile, and color. The amount of extractable astaxanthin in the crawfish byproducts was 3.02 mg/100 g of crawfish byproducts. FOA and FO had a similar alpha-linolenic acid (ALA) content (on a weight% basis). The FO was lighter and more yellow in color than FOA. The oxidation rate of FOA was lower than that of FO. When FO and FOA were heated to 30 °C, both oils exhibited minimal lipid oxidation with increasing heating time, whereas FO, when heated to 40, 50, 60 °C, had a higher lipid oxidation rate than FOA with increasing the heating time from 0 to 4 h. Astaxanthin was an effective antioxidant agent in FO when it was heated from 30 to 60 °C. The degradation of astaxanthin in FOA could be described by first order reaction kinetics. Astaxanthin was stable in flaxseed oil at 30 and 40 °C, while its stability decreased significantly at 50 and 60 °C. The rate of astaxanthin degradation in FOA was significantly influenced by temperature.     

基于Web的虚拟实验教学系统研究

随着Web技术的发展,数字化和虚拟化的实验教学系统被广泛关注。本文旨在研究基于Web技术和虚拟现实技术构建的虚拟实验教学系统,对虚拟实验室的主要构建类型进行了分析,并设计了该教学系统的功能模块,最后阐述了网络下虚拟实验教学系统的优势及其需要注意的问题。     

基于ARM9的多功能综合通信控制系统设计

介绍了基于ARM9硬件平台和嵌入式Linux系统的多功能综合通信控制系统的框架设计及各模块的功能。系统采用符合POSIX.1标准的C语言编写,实现了对下位机传送数据帧的采集、分析和存储,并能根据上位机的配置指令和数据传输指令分别对串口波特率、数据时间及手机短信号码等参数进行配置和存储数据的传输。     

基于水文过程的城市湖泊雨水利用系统的构建方法研究——以武汉梦泽湖为例

城市开发使天然湖泊的供水源大量受阻,导致湖泊在数量与面积上的大幅减少。而湖泊的减少,又加剧了城市内涝的发生。为了改变这种状况,众多城市开始营建人工湖,而兴建的城市人工湖又需要大量的市政补水来填充,实际上城市内涝也未得到有效缓解。本文在研究城市水文过程的基础上,以武汉市梦泽湖的应用研究为例,提出湖泊雨水利用系统的构建方法,予以最大效率地利用雨水来补充城市人工湖水源,同时减少城市内涝的发生。     

碱改性处理高岭土的性能研究

以高岭土为原料,通过高温焙烧、碱处理的方法,制备多孔的基质材料,采用气相色谱仪和自 动吸附仪对碱处理前后的焙烧高岭土进行比表面、孔体积和孔分布的测定,结果表明,碱处理后的焙烧高岭土孔体积明显增加,且具有明显的中孔特征,平均孔径在55埃米左右,且随着碱液浓度的增加,孔体积和比表面也有明显的提高.     

离轴型全息图再现象与背景光分离条件的另一种分析

本文从衍射波扩散出发,提出了另一种分析离轴型全息图再现象与背景光分离条件的方法。