Synthese of Phosphonoisoquinolinediones and 1,3,8-Trioxo-2-azaspiro[4.5]deca-6,9-dien-4-yl)methyl)phosphonates via Cycloaddition between Hydrogen Phosphonates and N-Acryloylaroylamides

有机膦酸酯在有机合成，阻燃材料和生物化学中发挥着举足轻重的作用，其中膦酰化杂环化合物一直在药理学和合成化学有着重要的应用，但是目前相关的合成方法却相对有限。近年来，磷自由基对不饱和烯烃体系的加成-环化反应一直是研究热点，也是合成膦酰化杂环化合物的重要方法之一。而本论文的主要内容如下： 第一部分：膦酰化异喹啉二酮衍生物的合成；发展了由Cu(OTf)2与TBHP引发的磷自由基与N-丙烯酰基芳甲酰胺衍生物的加成-环化反应，从而完成膦酰化异喹啉二酮衍生物的合成。该方法反应条件温和，操作简单，底物实用性较好，产率较高，成功实现了“一锅法”完成对P-C(sp3)键和异喹啉二酮分子骨架的构建，为一系列的异...Organophosphorus compounds have broad applications in the fields of organic synthesis, pharmaceuticals and agrochemicals. Heterocyclic phosphonates are ubiquitous and exhibit interesting biological activities and potential pharmaceutical applications. However, relevant synthetic methods are limited. Reactions involving organophosphorus radicals have a long history, and they are useful reactive spe...学位：理学硕士院系专业：化学化工学院_有机化学学号：2052013115158

Ge_xSi_(1-x)/Si中应变的会聚束电子衍射研究

介绍了会聚束电子衍射(CBED)技术与计算机模拟相结合测定Ge_xSi_(1-x)/Si化学梯度层中应变分布的实验结果，提供了一种高空间分辨率、高灵敏度，且适用于任何材料系中微区晶格常数测定及应变分布研究的技术途径

炼制高含硫原油时污水硫化物浓度对生化处理的影响

<正> 生化处理已广泛用作炼油污水的二级处理手段,它不仅能除酚、除油,而且除硫的效率也相当高,一般可达80～90％。据报道,当污水硫化物含量大于10毫克/升时,活性污泥就有上翻流失现象。许多炼厂反映,加工高硫原油时污水处理难度大。本文就炼制高硫原油时污水硫化物浓度对生化处理的影响,进行了初步考察

半绝缘GaAs衬底中位错对MESFETs旁栅效应的影响

在位错密度不同的LEC半绝缘(SI)GaAs衬底上离子注入制做MESFETs,观察衬底位错对MESFETs旁栅效应的影响。结果表明，衬底中高位错密度可以拟制旁栅效应

Dynamics of Urban Expansion in Circum-Bohai Sea Region

以环渤海三省两市为研究区,基于20世纪70年代末期以来5个时相的Landsat MSS/TM/ETM+遥感影像提取县级及以上城镇建成区的空间分布图形信息,采用扩展动态度、扩展强度和空间自相关指数等指标分析环渤海区域城镇扩展的时空动态特征。结果表明:(1)20世纪70年代末期以来,环渤海区域城镇用地不断扩展,各阶段扩展速度和扩展强度呈上升趋势,而扩展动态度趋于减少。(2)不同类型城镇扩展的总体趋势基本一致,但类型间差异亦较显著。(3)城镇扩展动态度的总体空间格局呈显著正相关,高值区空间分布的阶段性特征显著,且呈现沿交通干线分布和变化的特征。(4)城镇扩展强度总体上趋于随机分布,但局部地区呈集聚分布态势,高值区多较为孤立地分布在大城市或其周围地区,并表现出据点式的演化趋势。 &nbsp

Dynamic Changes and Driving Factors of Landscape Connectivity for Natural Wetland in Yellow River Delta

Landscape connectivity is an efficient index measuring the continuity of the spatial landscape units, and reflects the functional characteristics of the landscape. The coastal wetland ecosystem in the Yellow River Delta which have high ecosystem service functions have changed greatly due to local development. Therefore, it is necessary to analyze the dynamic changes of the natural wetland landscape in the Yellow River Delta and to explore the causes. In this study, Landsat TM images from 1991 to 2013 were used to evaluate the changes of landscape connectivity using connectivity index based on the graph theory. The dynamic characteristics of wetland landscape connectivity were analyzed at both regional and local scales and the driving factors of natural wetland landscape connectivity in the Yellow River Delta were also discussed. The results showed that the landscape connectivity of natural wetlands in the whole delta from1991 to 2013 was generally low and declining gradually, with the maximum possible connectivity index of less than 0.1, and the area of natural wetlands decreased by 548.75 km~2. The area of natural wetlands in the Kenli agro-ecological zone, Estuary agro-ecological zone and Shengli oilfield zone severely decreased, and the degree of landscape connectivity dropped significantly. By 2013, the landscape connectivity index in these zones dropped below 0.01. However, the landscape connectivity and wetland area of Yiqianer management station and the Yellow River mouth management station had increased. In the meantime, the connectivity indices of both stations were all above 0.5, and the possible connectivity of the Yellow River mouth management station increased from 0.203 to 0.360. It indicated lower landscape connective patterns in inland wetland than those in the Yellow River delta nature reserve. Farm land, artificial wetlands and construction land werethe main driving factors that affected the changes of wetland landscape connectivity. Therefore, we strongly recommended to expand the area of nature reserves in the future, and increase the number of footsteps to increase habitat connection to improve landscape connectivity in the Yellow River Delta