Research on Take-away Platform Users’ Repeat Ordering Intention: A Perspective of Perceived Price and Service Quality

近几年来，随着团购网站的兴起、打车软件的大热以及外卖平台的风靡，O2O电子商务的商机和细分领域正不断被挖掘和深耕。本文聚焦于外卖平台，外卖O2O模式与其他O2O模式最大的区别在于外卖O2O模式是配送上门，其他O2O模式（如团购）是到店体验，因此，配送质量是外卖O2O模式需要考虑的重要因素。现有的研究要么没有考虑配送质量，要么仅仅将其作为某个变量的一个测度项来研究，无法全面地体现配送质量对外卖平台用户满意和重复订餐意愿的影响。其次，外卖平台近两年来对新老用户采取满减、满返、满送及红包等价格补贴政策，而价格补贴政策是否会对用户的重复订餐意愿产生影响，也是值得深入研究和挖掘的。 本文结合外卖平台的...With the popularity of group-buying sites, taxi-hailing applications and take-away platforms, business opportunities and segments of O2O e-commerce has been deeply explored in recent years. This thesis focuses on take-away platforms. On the one hand, the biggest difference between take-away O2O e-commerce and other O2O e-commerce models is that take-away platforms/sellers deliver food to users whi...学位：管理学硕士院系专业：管理学院_管理科学与工程学号：1772013115108

Ammonia-sensitive Sol-Gel Fluorescent Films Made of Organically Modified Silicates

研究了基于有机杂化硅氧烷的氨光化学传感器 ;实验通过四甲氧基硅烷(TMOS)和二甲基二甲氧基硅烷(DiMe_DMOS)的缩聚 ,获得以氨基荧光素(AF)为荧光指示探针 ,对氨有灵敏荧光响应的溶胶 -凝胶敏感膜 ;实验考察了溶胶先驱体、各种比例杂化硅氧烷在玻璃支撑体上成膜后对体系 pH、NH3 浓度和响应时间的变化规律 ,发现DiMe_DMOS含量的变化改变杂化膜的极性 ,并使得敏感膜对NH3 有高荧光响应值 ,而对体系的pH不响应 ;实验结果表明在pH8.4 ,0.1mol/L磷酸盐缓冲溶液中 ,氨质量浓度与其相应的荧光强度在0.5～60mg/L范围内呈良好的线性关系 ,敏感膜对NH3 的95 %响应时间为4min ,常见的共存物质如氨基酸、胺和金属离子对NH3 测定未见有明显的干扰A photochemical sensor for the determination of ammonia consisting of organically modified silicates (ormosils) was developed. Ammonia- sensitive fluorescent sol-gel films were prepared by co- condensation of tetramethoxysilane (TMOS) and dimethyldimethoxysilane (DiMe- DMOS) in the presence of aminofluorescein and γ_[(2,3)_epoxypropyl]propyltrimethoxysilane (GOPS). The gel precursors with various ratios of alkylalkoxysilanes (ormosils) were deposited on glass supports and characterized in terms of their responses to pH, NH3 and time. It was found that introduction of DiMe- DMOS into the silane mixture influenced the polarity of the modified film and made the film having a high fluorescent response to ammonia but no response to pH changes. The hybrid film exhibits the most promising properties - sensitive to ammonia and insensitive to proton ions. The experimental results showed a linear range of ammonia concentrations from 0.5 to 60 mg/L in a buffer of 0.1 mol/L phosphate at pH 8.4. The response time(95%) for ammonia is 4.0 min. No significant interference of the common coexi_sting compounds, such as amines, amino acids and metallic ions, was observed on the determination of ammonia.国家863计划海洋领域资助项目(818-Q -09);; 福建省自然科学基金资助项目 (D0110001

离子／原子荧光光谱分析

本文概述了离子／原子荧光光谱分析的实验装置，详细讨论了该技术中的激发源、离子化器和该技术的特点及应用；展望了离子／原子荧光光谱分析的发展趋势和研究方向

强短脉冲供电的空心阴极灯激发离子／原子荧光光谱研究Ⅱ．矿物中微量钙的测定

强短脉冲供电的空心阴极灯激发离子／原子荧光光谱研究Ⅱ．矿物中微量钙的测定弓振斌，王小如，杨凡原，林雍静，黄本立（厦门大学化学系，厦门．３６１００５）自从以电感耦合等离子（ＩＣＰ）为原子化器的原子荧光光谱仪问世以来，许多研究者对该方法的优势表现出极大兴..

Protein, Gel Electrophoresis and the Application of Gel Electrophoresis in Protein Analysis

本文概述了离子/原子荧光光谱分析的实验装置，详细讨论了该技术中的激发源、离子化器和该技术的特点及应用；展望了离子/原子荧光光谱分析的发展趋势和研究方向。As very important biopolymers proteins have many biological Functions such as caalysis, transportstion, movement, deFence and regulation, etc.The isolation, puriFication and chsracterization of proteins are of great theoretical importance and practical value in understanding and utilizing their speciFic Functions and activities in liFe process.Gel electrophoresis is the most widely used and the most powerFul tool in protein determination.This article discusses gel electrophoresis and its application in protein analysis.First, it introduces propertics and Fractions of proteins, then discusses the reparation of protein samples, and Finally, reviews the gel electrophoresis techniques and teir application in protein iSolation, purFication and chsracterization.国家自然科学基

Flow Injection On-line Preconcentration with Active Carbon Fibre For Multi-element Determination in Water Samples Using ICP-AES

本文研究了新型吸附材料-活性碳纤维的在线分离富集特性，用fI活性碳纤维填充的锥形柱，实现痕量金属元素zn、PH、nI、CO、Cd、Mn的在线富集。经HnO3洗脱后.由ICP-AES检测，测定速率达30样/H，检出限（ng/Ml）分别为：0.4（zn）、4.0（PH）.0.9（nI）、0.4（CO）、0.4（Cd）、0.7（Mn），富集柱可使用多次。The study on the characters of the ACF applied to on-line column preconcentration was perFormed.The Flow-injection system using cone column Filled with ACP For preconcentration of trace amounts of heavy medals combined with an inductively coupled plasma atomic emission spectroscopy (ICP AES) is established.A sample Frequency of 30 s·h-1 could be achieved.The de tection limits For Zn, Ph, Ni, Co, Cd and Mn are 0.4, 4.0, 0.9, 0.4 and 0.7 μg/L, respec tively.The ACF cone column has the advantages of stable perFormance, simple operation, high preconcentration Factor and long liFe time.国家自然科学基

抑制氮氧化物排放的无烟燃煤技术及其在窑炉改造中的应用

抑制NO排放的无烟燃煤技术能够同时降低NO和烟黑的排放，提高燃烧效率。本文介绍了该技术用于窑炉改造的实例，并对改造前后的污染物排放结果进行了讨论

抑制氮氧化物排放的无烟燃煤技术及其在窑炉改造中的应用

抑制NO排放的无烟燃煤技术能够同时降低NO和烟黑的排放, 提高燃烧效率. 本文介绍了该技术用于窑炉改造的实例，并对改造前后的污染物排放结果进行了讨论

抑制氮氧化物无烟燃煤炉内煤气化过程

本文研究不同通风方式抑制氮氧化物无烟燃煤炉的炉内煤气化过程，测量了排底部、发生煤气区和干馏煤气区３个部位通风时该炉 ＮＯ和ＣＯ的排放浓度，分析了３个部位通风时气化室内的煤气成分、温度和停留时间对污染物形成的影响

The Effect of Species of Aerobic Microorganisms on Characteristic of Fiber Optic BOD Biosensors

采用同一制膜方法分别对异常汉逊酵母、枯草芽孢杆菌和恶臭假单胞菌进行等量包埋制备固定化微生物膜,并采用自制的光化学BOD微生物传感器试验了各种膜的响应时间、线性范围、重现性等方面的性能,从而选择性能最佳的耗氧微生物。同时也考察了温度、pH、盐度对不同微生物膜的影响。实验结果表明:以恶臭假单胞菌膜制备的传感膜性能最佳,测定BOD时间低于20 min,方法的重现性及精密度较好,其荧光强度变化速率最大值(dI/dt)的相对标准偏差为2.2%,在BOD值0~80 mg·L-1范围内呈现良好的线性关系,相比之下更适用于BOD的快速检测。After immobilizing three kinds of limnetic microorganisms on sol-gel ormosils, three BOD sensors that used these microbial sensing films were investigated. For the BOD sensing films immobilized Hansennula anomala, Bacillus subtilis and Pseudomonas putida, the linear fluctuant coefficient (R^2) was in the range of 0-160 mg·L-1 and 0. 958 5 for Hansennula anomala, 0-160 mg·L-1 and 0. 956 0 for Bacillus subtilis , 0-80 mg·L-1 and 0. 990 6 for Pseudomonas putida, respectively. Reproducible responses could all be obtained below 3%. The effect of pH and sodium chloride concentration to the three microbial films were studied. After comparing these microbial films, sensing film with Pseudomonas putida is the best in respect of sensitivity, stability and reproducibility.国家863计划环境与资源领域资助项目(2001AA635100) 国家自然科学基金委员会与香港 研究资助局联合科研基金资助项目