鉱業活動による土地変容の時空間分析

Tohoku University博士（学術）thesi

大学英语石化现象原因分析及对策

中介语石化是二语习得中一个普遍现象。本文通过调查大学生学习英语的现状,分析了目前普遍存在于大学英语学习过程中的石化现象及石化产生的隐性因素和显性因素,提出缓解石化的策略以促进英语的学习和教学

中国金融改革深化论

八十年代,我国金融体制改革迈出了重大步伐,但也应清醒看到存在的问题,认真总结经验教训

基于高斯混合模型 Varian NovalisTX 直线加速器盆腔肿瘤放疗摆位误差分布预测模型的构建

【目的】构建 Varian NovalisTX 直线加速器盆腔肿瘤放疗摆位误差分布预测模型。【方法】选取加速器 治 疗 30 例 盆 腔 肿 瘤 患 者 先 验 IGRT 摆 位 误 差 数 据 ，采 用 高 斯 混 合 模 型 构 建 误 差 分 布 预 测 模 型 ，并 求 解 分 析 模 型 参数。【结果】由模型参数可知摆位误差主要往μ1~μ4 四个中心点方向集中；中心点坐标表明误差在 Vrt 方向（-3.88~4.28）mm 和 Lng 方 向（-2.41~1.54）mm 较 大 ，Lat 方 向（-1.85~0.72）mm 较 小 ；误 差 可 能 性 往 μ2 和 μ4 中 心（0.301、0.310）较μ1 和μ3 中心（0.190、0.196）大；摆位误差标准差可达 5.2 mm。【结论】高斯混合模型对盆腔摆位 误差分布进行定量描述和预测分析，为缺少 IGRT 的盆腔肿瘤放疗摆位误差控制及肿瘤计划靶区外扩提供参考

新型磷杂菲酯类衍生物的合成及热稳定性研究

磷杂菲衍生物是一类重要的阻燃材料.由磷杂菲与甲醛反应得到的中间体分别与各种酰氯反应得到一系列新型的磷杂菲酯类衍生物,利用1H NMR、13C NMR、31P NMR、FT-IR、HR-MS和ESI-MS对化合物的结构做了表征.讨论了催化剂用量、物料比、溶剂、反应物浓度、反应时间及温度对反应的影响,并对反应进行优化.对代表化合物的热稳定性做了测试,结果表明这类磷杂菲酯类衍生物具有良好的热稳定性,可以作为阻燃材料使用

Biomass Cell Wall Component Structural Interpretation and Bonding Mechanism

生物质转化为高值化材料的关键一步是对组分进行清洁温和分离,然后将分离后的组分进行生物和化学转化,获得高性能材料。然而,由于生物质结构复杂,人们对其了解的局限导致对它们有效分离缺乏理论上的指向,使得目前的分离技术多是一种工艺层面的探索。迄今为止,尚没有高效的集成化生物质清洁分离技术体系,即在一个工艺过程中将生物质不同的组分能以较完整的分子结构形式清洁有效分离出来。由于生物质现代转化利用途径需要在保持较完整结构的基础上将主要组分清洁有效分离开来,然后对不同组分进行有目的的转化利用。因此,尽管生物质组分转化利用有广阔的应用前景,但生物质组分的清洁有效分离仍是一个瓶颈限制,是一个难点问题。生物质组分分离的关键是将断裂木质素组分和半纤维素组分之间的结合键或有选择性断裂木质素分子内的结合键,进一步达到清洁分离组分的目的。该研究拟从生物质组分间化学结合键的差异性以及空间构型的差异性中寻找其对不同差异介质环境中的反应机制,从而进一步提出氧基化学分离新途径的导向指引,即利用木质素侧链的α、β、γ-与半纤维素组分之间的酯键等结合键或木质素分子内不同化学键对不同微差异介质环境中化学体系中O2分子的敏感性不同,探索其可能的分子内或分子外结合键的断裂途径,从而实现清洁温和分离纤维素、半纤维素和木质素组分的目的,为生物质的高值化利用奠定基础。The key procedure of converting the biomass into high value materials is to separate the fractions clean and moderately and then to conduct the biological or chemical conversion of the separated fractions to obtain the high value materials. However, it, the lack of theoretical guide of effective separation on account of the limitation of our acquirement about the complexity of biomass structure, makes the separation technology become an exploration on process level. So far, there is no efficient integrated system for clean separation, which can separates different fractions at a fairly complete molecular structure clean and effectively in a process. The way of modern biomass utilization needs to separate its fractions clean and effectively under the premise of a fairly complete molecular structure and then carry out the purposeful conversion and utilization of different fractions. Despite the biomass conversion and utilization have broad application prospects, the clean and effective separation is still a bottleneck restriction and a difficult problem. The key to the separation of biomass components is to break the bond between lignin and hemicellulose or to selectively break the intramolecular bond among lignin achieving the purpose of clean separation. This study intends to find the reaction mechanism under different medium environment from the differences of the bonds among the fractions and the differences of spatial configuration, and then propose an orientation guidance of oxygen chemical separation. Scilicet, making use of the different sensitivities to O2 of different bonds, which between lignin side chain of alpha, beta, gamma- and bonds among hemicellulose fractions, such as easter bond, or intramolecular bond among lignin molecules, to explore the possible fracture way in or between the molecular. Furthermore, on the basis of the above work, this study intends to achieve the purpose of a clean and moderate separation of cellulose, hemicellulose and lignin fractions, laying a foundation for high value utilization of biomass

The Current Situation and Protection Measures of Amphibians and Reptiles Diversity of Huaihe River basin in Anhui

经过调查统计,发现淮河流域(安徽段)现有两栖动物11种,其中古北界2种,东洋界5种,广布种4种;爬行动物23种,属于古北界4种,东洋界13种,广布种6种。区系特点明显,属于古北界向东洋界的过渡区,东洋界和广布种种类分布相对丰富。相似系数分析表明沱湖和女山湖相似系数最高,说明其生境和其他两个保护区相比更为优越。此研究有助于了解该地区两栖爬行动物的多样性现状,为进一步加强资源的保护和可持续利用提供参考。The amphibians and reptiles diversity of Huaihe River basin in Anhui has been investigated and studied.The result indicates that 11 amphibian species have been found,2 of them are pale arctic realm,5 oriental species and 4 widespread species.23 reptile species have been found,4 of them are pale arctic realm,13 oriental species and 6 widespread species.The fauna feature was obvious.The pale arctic species are seldom,the oriental species and the widespread species are rich.Analysis indicates that the similar coefficient of Tuohu and Nvsanhu are the highest.The conclusion is that the diversity of amphibians and reptiles in this area can be illustrated;the environment and wildlife resources can be utilized reasonably after more protection.安徽科技学院重点学科建设基金项目(YZD2004-19)资

Research Progress of Metal Material Liquid Forming Technology

随着汽车工业的迅速发展以及市场竞争对铸件质量要求的提高,推动了金属材料液态成型技术发展。从20世纪70年代压铸技术的广泛运用,到90年代挤压铸造技术的不断完善,随后挤压压铸技术不断创新,使液态成型技术向多学科渗透融合发展,应用领域不断拓展,铸件用量逐年上升。重点介绍了压铸、挤压铸造、挤压压铸这三种重要的成型技术发展以及取得的最新成果。With the rapid development of auto industry and the market competition on the increase of the requirement of the casting quality,the development of metal material liquid forming technology was promoted.From the extensive use of the die casting technology in the nineteen seventies to constant maturity of the 90's the squeeze casting technology,and then the continuous innovation of squeezing die casting,the liquid forming technology for multidisciplinary permeated and developed,application area continued to expand,and casting quantities increased year by year.The development and the latest achievements of three kinds of important forming technologies(die casting,squeezing casting and squeezing die casting) were mainly introduced.贵州省(贵阳市)工业攻关项目(黔科合GY字[2012]3004;筑科合同[2012101]2-13号

Al2O3含量对PVDF/PVC/Al2O3共混中空纤维膜的影响

以聚偏氯乙烯(PVDF)、聚氯乙烯(PVC)和纳米氧化铝(Al2O3)三元共混,制备中空纤维膜,探讨Al2O3含量对膜性能的影 响。结 果表明,由于 适量Al2O3的加入,中空纤维膜膜孔结构明显改善,大孔减少,微孔增多;亲水性明显提高。Al2O3为最佳含量3%时,水通量和截留率分别达到了301L/(h·m2)和77.2%