200 research outputs found

    Heterogeneous catalyze epoxidation of FAME(Fatty Acid Methyl Ester)

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    随着塑料工业的飞速发展,对增塑剂的需求量越来越大,同时,人们环保意识的增强也对增塑剂提出了更高的卫生要求。环氧脂肪酸甲酯是新近开发成功的一种新型无毒环保的增塑剂,它由不饱和脂肪酸甲酯双键的环氧化得到。 本文研究工作分为两部分,第一部分是对磷钨酸季铵盐催化脂肪酸甲酯环氧化的工艺改进,通过对工艺参数的优化以及催化剂中季铵盐种类的调变,找到了一种兼有较高反应活性及较高回收率的催化剂,在此过程中发现了季铵盐烷烃长链的不同对催化剂性能的影响规律,并且找到了一种有效的回收催化剂的方法,切实解决了该工艺催化剂回收率低的问题;第二部分是对以空气为氧化剂(气相氧化法),负载型Au-Pd催化脂肪酸甲酯环氧化的工...It’s growing demand for plasticizers with the rapid development of the plastics industry, simultaneously, people have a higher hygiene requirements with awareness of environmental protection. Epoxy FAME comes from the epoxidation of double bonds of unsaturated FAME. This study can be divided into two parts. The first part is the process improvement of FAME epoxidation catalyzed by phosphotungstic...学位:理学硕士院系专业:化学化工学院化学系_物理化学(含化学物理)学号:2052008115173

    Research and Design of Production Equipment Defect Management System for Power Enterprise

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    在分析某发电企业管理流程的基础上,找出当前生产中存在的问题,针对经营环节重点进行系统需求分析,设计发电企业生产设备缺陷管理系统,提升发电企业的管理水平,实现发电企业现代化管理。 系统采用.NET平台、SQLServer数据库和B/S三层体系架构进行软件开发,详细描述发电企业信息管理流程中的设备台账信息录入、生产运行信息记录筛选、安全监察信息收集调用、大坝水文信息采集等功能设计,实现了生产设备管理功能模块。 本文介绍研究背景、研究目标和业务需求,描述系统设计思路、系统需求分析、系统总体架构设计方案、系统设计的关键技术、系统功能设计方法和数据库设计技术,并实现了系统的主要功能模块。In the foundation to analyzing management process of a power enterprise, find out the problems existing in the production, directed by system for automated processing of link key needs analysis. Design of power company production equipment defect management system, the purpose is to upgrade the power enterprise management level, to realize the generation of modern enterprise management requirement...学位:工程硕士院系专业:软件学院_工程硕士(软件工程)学号:X201023019

    A Study on the Public Company's Merger&Acquisition

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    论文摘要 我国上市公司的并购重组已走过了十余年的发展历程,理论不断丰富,制度日趋规范,模式不断创新,实践活动蓬勃发展,在我国的产业整合升级以及证券市场的发展中呈现出一幅多彩的资本运作画卷。 在近两年经济衰退、营商环境恶化及估值重心下移的新背景下,从实际情况看,有的龙头上市公司在寻求并购机会,推进行业整合;有的困难公司则在等待重组机会。上市公司的并购重组活动,有利于提高上市公司质量,改善公司治理水平,提高公司核心竞争力,渡过短期乃至中期的发展难关。 在过去的十余年间,业界及学界对上市公司并购重组的理论研究已有不少有益的成果,但由于我国的股市起步较晚,上市公司的并购近几年才大规模的兴起,因此...Abstract The merger & acquisition of public company in our country has passed through tens of years. The relative theories are more plentiful, rules and regulations are more formally, models are innovated, and practice is growing. Nowadays, the globally recession and financial crisis has leaded to the economic conditions turn for the worse. Some leaders companies are looking for chance to merger...学位:工商管理硕士院系专业:管理学院工商管理教育中心(MBA中心)_工商管理硕士(MBA)学号:X20031537

    Asymmetric Transfer Hydrogenation of Ketones Catalyzed by Chiral Multidentate Aminophosphine Ligands/Iron Cluster

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    从廉价易得、绿色环保的铁簇合物Fe_3(CO)_(12)出发,开展了其与手性多齿胺膦配体(R,R,R,R)-PN_4H_6原位生成的催化体系在酮; 的不对称转移氢化中的应用研究.通过考察温度、添加剂等影响因素,探索最优的反应条件,并将其进一步应用于多种芳香酮的不对称转移氢化反应,得到高达96; % ee的对映选择性.As one of the most abundant metals on earth, iron is cheap and low toxicity. Herein we reported the asymmetric transfer hydrogenation of (ATH) ketones catalyzed by the system generated in situ from chiral multidentate aminophosphine ligand (R, R, R, R)-PN4H6 and Fe-3(CO)(12). The effects of temperature and additive on the ATH of propiophenone were examined. After optimizing the reaction conditions, we applied the catalytic system to the ATH of various aromatic ketones, obtaining the corresponding optical active alcohols with high enantioselectivities (up to 96% ee).National Natural Science Foundation of China [21173176, 21673190];; Fundamental Research Funds for the Central Universities [20720150040

    化学反应的价键理论研究

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    根据价键波函数的对称性及基态、激发态化学键与键表的对应 ,可以把轨道对称守恒原理和键对称规律表述成“价键结构对称性匹配” .价键结构对称规则通过对反应物和产物的价键结构进行对称性分析 ,可以直接预测化学反应活性 ,无需依赖理论计算结果 .在价键结构对称性分析的基础上 ,应用多VB结构计算方法 ,建立了反应H +HLi→H2 +Li和H +LiH→HLiH(cyclic)→HLi+H的曲线交叉VB图 ,讨论了能垒及过渡态的形成机制 .计算结果表明 ,H原子交换反应H +LiH HLi+H是一个两步过程

    空间机器人高可信软件检错技术

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    提出一套适用于空间机器人的高可信软件设计模型和算法,将空间机器人软件错误检测分为单元级和系统级2 个层级,针对单元 级检测设计程序基本块模型以及基于该模型的数据流和控制流错误检测算法;针对分布式软件系统级的错误检测,设计多节点自适应冗余 模型,在此基础上设计基于微检查点的错误检测算法,对空间机器人软件系统的错误检测形成一个完整覆盖,该方法已得到成功应用。国家“863”计划基金资助项目(2005AA742013

    自适应光学对大气扰动波前的补偿效果研究:II.水平大气传输时…

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    讨论了光波在水平大气湍流中传输时的情况。计算结果表明自适应光学系统的补偿效果与光波传播路径上的横向风有很大的关系。大气湍流的强度越大, 自适应光学系统的截止频率越高, 横向风的影响也越大。计算结果还表明在相同的r0 或者相同的大气湍流强度下, 球面波所受大气扰动的自适应光学补偿效果受横向风的影响要比平面波的厉害。本文还将理论分析的结果和数值模拟的结果进行了比较, 表明数值模拟结果受横向风的影响比理论分析结果受横向风的影响大。最后, 文中分析了以上现象并对此作出了合理的解释

    Compositions of Organic Acids in PM_(10) Emission Sources in Xiamen Urban Atmosphere

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    对厦门城区大气颗粒物PM10中有机酸的可能来源,如烹调油烟、生物质燃烧颗粒、汽车尾气和土壤/路面扬尘等4种不同排放源,采用再悬浮混合箱得到PM10样品.采用bf3/正丁醇衍生-gC/MS分析方法,测定了包括二元羧酸、脂肪酸和芳香酸共15种有机酸.结果表明,烹调油烟中有机酸的含量远高于其它颗粒物,最高可达53%,其中亚油酸和油酸的含量最高,为24%±14%;而汽车尾气颗粒物中乙二酸的含量最高,其次为邻苯二甲酸PH;汽油燃烧颗粒物中己二酸与壬二酸的比值显著高于其它样品,可用于环境大气中二元羧酸的人为和生物来源的定性判断.除发电机排放样品外,其它样品中丙二酸与丁二酸的比值(0.07~0.44)远低于环境样品中该比值范围(0.61~3.93),表明丙二酸与丁二酸的比值可用于环境大气中二元羧酸的一次/二次来源的定性判断.The possible organic acid emission sources in PM10 in Xiamen urban atmosphere such as cooking,biomass burning,vehicle exhaust and soil/dust were obtained using a re-suspension test chamber.A total of 15 organic acids including dicarboxylic acids,fatty acids and aromatic acids were determined using GC/MS after derivatization with BF3/n-butanol.The results showed that the highest total concentration of 15 organic acids(53%) was found in cooking emission and the average concentration of the sum of linoleic acid and oleic acid was 24%±14%.However,oxalic acid was the most abundant species followed by phthalic acid in gasoline vehicle exhaust.The ratios of adipic to azelaic acid in gasoline combustion emissions were significantly higher than those in other emission sources,which can be used to qualitatively differentiate anthropogenic and biological source of dicarboxylic acids in atmospheric samples.The ratios of malonic to succinic acid in source emissions(except gasoline generator emissions) were lower(0.07-0.44) than ambient PM10samples(0.61-3.93),which can be used to qualitatively differentiate the primary source and the secondary source of dicarboxylic acids in urban PM10.国家自然科学基金项目(40971257;41171365); 环境保护公益性行业科研专项(201009004); 福建省自然科学基金计划项目(2009J05106

    Environment Security Monitoring System for Offshore Caged Fish and Water Quality

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    为了更好地开展渔业养殖中深水网箱中鱼群状态与水质环境的安全监测,提出了一种深水网箱鱼群与水质环境安全远程监测系统.该系统使用声学方式对鱼群分布状况进行监测;同时采用传感器对水质环境的温度、溶解氧、p H值等进行监测,监测结果通过无线数据传输方式实时传送至微处理器,完成信号去噪、数据提取、显示及报警等.实验结果表明,该监测系统性能稳定可靠,结合嵌入式控制技术与无线数据传输技术,监测操作简便,移动性好;同时兼顾鱼群与水质环境安全,监测更全面到位,在推广深水网箱养殖安全配套设施上具有良好的应用前景.Environment monitoring of fish activity state and water quality is the key to offshore cage safety management.A remote monitoring system for offshore caged fish and water quality is developed in the research.The fish distribution and abundance are monitored strategically using acoustic transducers in the system.Meanwhile,some parameters of water quality are obtained using various sensors,such as temperature sensor,dissolved oxygen sensor and p H sensor. Then the collected data are sent to the user monitor terminal in real time through wireless transmission module.Finally,the results are displayed on a 7-inch liquid crystal display screen( LCD) after data processing. The experiment has been conducted to verify the excellent performance of this system.Combined with embedded control technology and wireless data transmission technology,the flexibility and mobility are improved significantly. Besides,both fish activity and water quality are taken into account,making the monitoring more comprehensive.The results suggest that the system has good application prospects.国家海洋局海洋公益性行业科研专项(201505027-2

    溶瘤病毒T-Vec应用于肿瘤治疗的临床研究进展

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    T-Vec(talimogene laherparepvec)是由Ⅰ型单纯疱疹病毒(HSV-1)改造而来的一种溶瘤病毒,能够选择性地在恶性肿瘤细胞中复制而不伤及其他正常细胞。T-Vec在治疗晚期黑色素瘤患者的Ⅲ期临床试验中显示出良好的安全性和肿瘤治疗效果,已于2015年经美国FDA批准用于治疗晚期黑色素瘤。为了提高T-Vec的疗效,扩大其应用范围,T-Vec联合其他抗肿瘤疗法以及应用于其他肿瘤的临床试验仍在陆续开展。近期,T-Vec联合免疫检查点抑制剂在治疗晚期黑色素瘤的临床试验中取得新进展,临床数据显示T-Vec联合疗法具有更强的抗肿瘤活性。此外,T-Vec在治疗头颈癌、胰腺癌、肝癌等肿瘤的临床研究中也取得了一定进展。本文对近年来T-Vec治疗肿瘤的临床试验的相关研究进展做一综述。分子疫苗学和分子诊断学国家重点实验室资助项目(No.2016ZY005);;厦门大学国家传染病诊断试剂与疫苗工程技术研究中心自主项目(No.XDHT2016494A)~
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