304 research outputs found
Study on High-efficiency and Low-cost Process Development of Ethoxyquin
乙氧基喹啉(EMQ)作为一类性能优良、价格低廉的酮胺类抗氧化剂,广泛应用于饲料抗氧化、橡胶防老化、水果保鲜等领域,是目前饲料行业首选的抗氧化剂。国内外报道的EMQ合成工艺存在诸多不足,如反应时间长、后处理工序繁杂、工艺成本高等。针对目前以对氨基苯乙醚和丙酮为原料生产EMQ工艺存在的不足,本论文提出以原料对氨基苯乙醚的转化率及单耗、产物EMQ的选择性及产物收率为优化目标,通过考察各种因素对反应结果的影响,选择较佳的EMQ合成工艺进行优化,确定最适宜的合成工艺条件,在提高产物收率的同时降低对氨基苯乙醚单耗,从而降低工艺成本,简化工艺流程,为开发工业化高效生产EMQ工艺奠定基础。 在以对氨基苯乙醚...As a preferred antioxidant in industries of feed, ethoxyquin (EMQ) is widely applied in many industries with excellent performance and low cost. Considering the defects in the synthetic process of EMQ as reported, for instance, long reaction time, complex post-treatment and high process cost, a simple, low-cost and optimal synthetic process of EMQ with p-phenetidine and acetone is proposed by inve...学位:工程硕士院系专业:化学化工学院_工程硕士(化学工程)学号:2062013115147
回転浮遊液滴の形状及び振動に関する研究
九州大学応用力学研究所研究集会報告 No.20ME-S7 「非線形波動の数理と物理」RIAM Symposium No.20ME-S7 Mathematics and Physics in Nonlinear waves液滴の挙動解析や制御に関する研究は宇宙環境での新しい材料の開発や車・航空機のエンジンの燃料噴霧の問題など幅広い分野で応用が期待されている. 本研究はそれらの基礎研究の一環として, 本研究では浮遊する液滴を回転させたときの形状や振動及び大変形挙動を理論的に解析することを目的としている. 理論に関してはJAXA(宇宙航空研究開発機構)による回転浮遊液滴の実験結果との検証も行っている
基于SODA资料的南海表层风能输入的空间分布与长期趋势研究
海面风不仅是驱动上层海洋运动的主要动力,其能量也是维持海洋表层流动的主要机械能来源。为了分析南海表层流风能输入的变化,用SODA(Simple Ocean Data Assimilation)(1901—2010)资料估算了风向南海表层流(表层地转流+表层非地转流)的能量输入。结果表明,风向南海表层流、表层地转流和表层非地转流输入的能量总体均呈减少趋势, 110年间分别减小了约56%、65%和49%。导致风能输入减小的最主要因素是风应力的减弱(减小了35%)。由于南海受季风系统的控制,风向表层流及其各成分输入的能量呈现出显著的季节性变化。冬季风能输入最强,高值区位于南海西部及北部区域,呈一个显著的\"回力镖\"状结构。这些结果对深入认识南海环流具有理论意义。国家自然科学基金项目(41676021、41541040、91228202);;近海海洋环境科学国家重点实验室开放课题(MELRS1608)~
三硝基甲苯起爆机理实验研究
用单脉冲化学激波管实验方法,使用自由基清扫剂和对比速率,测定了邻位和对位硝基甲苯在高温下,裂解瞬间(500μs)的化学反应机理,并测定了化学反应速率常数。作为邻位硝基甲苯的同分异构体,对位硝基甲苯的主要裂解通道与其不同。通过实验发现了邻位硝基甲苯的裂解重要通道,测到它的产物1氧-2氮-3,4-环丁二烯基异恶唑(Anthranil)在瞬间随温度变化生成和很快消失的过程。由此,测得这一化学性质极不稳定的产物的消失速率常数为:k(Anthrani1)=3.7*10~{15}·exp(-25800/T)(s~{-1})。分析这一过程的机理,认为第一 步是硝基甲苯的裂解,第二步是Anthranil的生成,第三步是Anthranil中的N-O键的断裂
SERS Study of Apo-Metallothionein Adsorbed on Roughened Gold Surfaces
利用表面增强拉曼光谱(SERS)技术研究了金属硫蛋白(MT)与脱金属硫蛋白(apo-MT)在粗糙金表面的吸附行为。结果表明:MT通过氨基与金作用;apo-MT与金的作用位点受制备方法影响:在溶液中预制的apo-MT通过半胱氨酸残基的巯基与金结合,在金表面制备的apo-MT通过氨基和巯基与金结合。SERS更适合于研究MT的结构特征。The adsorption of metallothionein and apo-metallothionein on roughened Au surfaces was studied by SERS technique.The results indicate that MT is adsorbed via-NH2 group on roughened gold surfaces.The adsorption site of apo-MT on Au is determined by the preparation method of apo-MT.The apo-MT prepared in solution is adsorbed via the-SH group on Au whereas that prepared on the Au surface is adsorbed via-SH and-NH2.国家自然科学基金(20503040,20773165);; 973计划(2007CB935603);; 厦门大学固体表面物理化学国家重点实验室开放课题项目资
空气正激波后电子浓度的测量
用改进了的磁探针和离子采集器,在φ800毫米低密度激波管中,测量了空气正激波后的电子浓度,得到了与等人的平衡理论计算一致的结果。在大Ma_s,数、低密度下,实验结果表现出有“过剩”的电子浓度,这与林绍基等人的结果是一致的
Study on landscape pattern changes in islands under stress of rapid urbanization
以厦门岛为例,通过一般景观格局分析指标和特殊景观格局分析指标,研究城市化进程中海岛生态景观格局的变化以及人工景观对自然景观的胁迫作用。结果显示:从1987年至2004年,人工景观对自然景观的胁迫作用迅速增加;厦门岛建成区占海岛面积的比例迅速增长,而斑块数量明显减少;厦门岛景观多样性迅速下降,同时破碎度指数和优势度迅速提高;受到海岸带开发活动影响,海岛岸线趋向平滑,海岛形状逐步趋向圆形;厦门岛人工景观对自然景观的胁迫程度逐步升高,城市化侵蚀指数也快速提高。Several common and special landscape indices were used to analyze the landscape pattern changes of Xiamen islands and the stress of artificial landscape to the natural landscapes during urbanization process.The results showed that the landscape pattern of Xiamen islands was altered observably and the stress of the artificial landscape to natural landscape were increased rapidly.The ratio of urban land area to the total islands area was increased and the number of the patches was decreased.The landscape diversity was decreased,meanwhile the landscape fragmentation and dominance were increased respectively.Because of the coastal reclamation,the island's coastal line tended to be simple and smooth,and the shape closed to a circle.The stress of the urban land to natural landscapes was aggravated with the urbanization invasion index increase.国家自然科学基金资助项目(40701059);中国科学院知识创新工程重要方向项目(KZCX2-YW-422-1);青年人才领域前沿项目(07l4081d10
〔報文〕敦煌莫高窟第285窟南壁龕楣の彩色材料および技法
In this research, the painting on the arch over the niche was investigated by an in situ analysis of the initial colouring of the mural painting in Mogao Cave 285. The colorants for the painting on the arch over the niche were assumed to be vermilion, red organic colorant, red lead, orpiment, green colorant of copper compound, indigo and lapis lazuli. Initial colour of the vine pattern, corded belt and flame motifs painted on the arch over the niche was investigated. The corded belt painted along the niche at the entrance is divided into sections with a thin yellow belt. The sections are colored either red to orange or green to blue, and it is assumed that these color patterns were in alternating order
Human-induced disturbance on the understory plant diversity of urban forest:a case study of Xiamen
以厦门城市森林林下层植被为研究对象,重点研究台湾相思群落中林下灌草层植物多样性与土地利用类型、人为干扰程度之间的相关性;选用基于重要值的4种多样性指数,比较不同邻接用地类型城市森林群落多样性的差异;运用主成分分析、CCA排序以及多元回归等方法对城市森林灌草层植物多样性格局进行解释。结果表明:人为踩踏、垃圾堆积程度、人为挖掘、可到达容易程度等因子对厦门城市森林灌草层植物多样性分布格局有重要影响;厦门城市森林群落草本层β多样性沿着邻接商业用地、交通用地、工业用地、居住用地的方向逐渐增加,而灌木层β多样性沿着该环境梯度的方向却逐渐降低。This study is aimed at understanding anthropogenic impact on the understory plant diversity around the municipal area of Xiamen in Fujian Province,SE China.Four indexes were employed to differentiate the diversity of urban forests adjacent to different land use types.Principle Component Analysis(PCA)and Canonical Correspondence Analusis(CCA)methods were applied in our study.The results showed that human trample,dustheap,digging,accessibility and other factors have great influence on the understory plant diversity.Herb β diversity of urban forest increased along the land use gradient from commercial,transportation,industrial to residential,while shrub β diversity decreased gradually along this environment gradient.中国科学院知识创新工程重要方向资助项目(KZCX2-YW-422);厦门市科技计划资助项目(3502Z20072002);中国科学院知识创新工程青年人才领域前沿资助项
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