Design and Fabrication of Stack Micro-Direct Methanol Fuel CellUsing Silicon and PDMS

在堆栈式微型直接甲醇燃料电池μ-dMfC(MICrO-dIrECT METHAnOl fuEl CEll)中,为了避免硅基流场板因为封装压力过大而破裂,采用了硅和PdMS(POlydIMETHylSIlOXAnE,聚二甲基硅氧烷)材料分别制作阳极和阴极流场板。首先,采用微机电系统MEMS(MICrO-ElECTrO-MECHAnICAl SySTEMS)技术制作硅基阳极流场板。其次,通过铜箔与阴极流场板一体成型、有机清洗和PdMS表面活化等改进措施显著提升了PdMS阴极流场板金属化的能力。最后,比较和分析阳极流场板上3种不同结构的流道形式的堆栈式μ-dMfC的输出性能。实验结果表明,活化后的PdMS阴极流场板与Cr/Au的粘附性能和粘接强度显著提高,同时阳极流场板的流道一半开设为凸台,一半开设为通孔时,其堆栈式μ-dMfC的输出性能最优。最大输出电流密度为81.25 MA/CM2,最大输出功率为7.73 MW/CM2。采用硅和PdMS材料分别制作流场板,不仅简化了堆栈式μ-dMfC的结构,而且能够缓冲锁紧力,有效保护硅基阳极流场板。同时优化阳极流场板上的流道结构,能够有效提升堆栈式μ-dMfC的输出性能。In order to avoid cracks of the silicon flow field plate caused by high package pressure,silicon and PDMS(Polydimethylsiloxane)are used as anodic and cathode flow field plate respectively in the stack μ-DMFC(Micro-direct methanol fuel cell).The anodic flow field plate based on silicon is fabricated with MEMS(Micro-Electro-Mechanical Systems)technology,and cathode flow field plate is fabricated using PDMS and its metallic performance is evidently improved by means of integral shaping of copper foil and cathode flow field plate,organic cleaning and activation on PDMS surface.The output of stack μ-DMFC is tested and analyzed,in which 3 different flow channel structures on the anodic plate are introduced.Tested results verify that adhesive capability and strengthen between post-activated PDMS and Cr/Au are greatly improved,and when micro blocks and through holes are introduced alternately in the flow channel of anodic flow field plate the stack μ-DMFC can obtain the maximum output,with voltage of 0.5 V,current density of 81.25 mA/cm2 and output power density of 7.73 mW/cm2.This study shows that using silicon and PDMS as flow field plate respectively not only simplifies the structure of stack μ-DMFC but also cushions clamping force and effectively protects anodic flow field plate,and furthermore to increase the output of stack μ-DMFC by optimizing structure of flow channels on the anodic flow field plate.国家自然科学基金重点项目(60936003

Control method for aircraft wake vortex based on Rayleigh-Ludwig instability

在飞机飞行的过程中尾涡会伴随着升力产生,威胁后机的飞行安全.在简化机翼模型上添加扰流片,通过一个矩形翼以引入一个与主翼尾涡大小不同、方向相反的小涡,构建尾流自消散四涡系统,以期诱发尾涡的rAylEIgH-ludWIg相交不稳定性.通过改变扰流片的大小形状,调整模型的攻角和拖曳速度,采用粒子图像速度场仪测量系统定量研究在低雷诺数下单主翼尾涡发展特性以及双涡相互作用特性.研究表明:在未添加扰流片时,尾涡环量在45个翼展内相对于初始环量基本保持不变;在添加扰流片的情况下尾涡的环量衰减可以达到35%~55%,而未添加的基本翼型的尾涡的环量则几乎保持不变,这说明添加适当的扰流片能诱发尾涡的rAylEIgH-ludWIg相交不稳定性,加速尾涡的消散,当小涡和主涡的初始环量比为-0.489、初始距离比为0.5时,45个翼展范围内,尾涡环量衰减55.9%.本文系统性的实验结果可以为低尾流机翼的设计提供参考依据.The aircraft wake vortex is an inherent flow phenomenon due to the lift generation mechanism,which has a negative impact on the flight safety.By adding a set of specially designed spoiler,a rectangular wing was designed to generate a pair of weaker vortices,which had different sizes and opposite direction compared to main wing vortices,thereby constructing a self-destructive four-vortex wake system to induce Rayleigh-Ludwig instability.Under different experimental conditions,in terms of changing the size or shape of the spoiler,towing speed and angle of attack,the wake vortex development of the test model,that both with and without spoiler,as well as the circulation analysis,were acquired particle image velocimetry( PIV) measurements under the low Reynolds number.The study demonstrates that the decrease in circulation was 35% to55% in 45 wingspans when spoilers are introduced,whereas the counterpart of the baseline airfoil,without spoilers,is nearly kept steadily,which reveal the application possibility of Rayleigh-Ludwig instability in alleviating the wake vortex.As the initial circulation ratio equals to- 0.489 and the initial distance ratio is0.5,the circulation of the primary vortex reduce most significantly( 55.9%) in 45 wingspans.Results would provide a scheme in the design of airfoils with weaker vortices.国家自然科学基金(11072206

Structure analysis of anode flow field of micro direct methanol fuel cell based on Fluent

微型直接甲醇燃料电池中阳极流场结构对电池的性能有着重要的影响。为了合理设计阳极流场结构,改善甲醇燃料在阳极流场中的分布,采用计算流体动力学(Cfd)软件fluEnT对微型直接甲醇燃料电池进行建模并仿真分析。分析比较了点型、平行和蛇形3种不同流场图案下得到的压降与流速分布,得出蛇形流场能够更有利于甲醇燃料的均匀分配。在此基础上分别建立不同流道宽度(800,400,200,100μM)的蛇形流场模型,通过仿真计算甲醇燃料的分布情况来分析其对燃料电池性能的影响,并结合实验结果进行对比得出流道宽度为200~400μM之间为优化值。Structure of anode flow field is very important for micro direct methanol fuel cell.To optimize the structure of the anode flow field and the distribution of methanol in it,a model of micro direct methanol fuel cell is created and analyzed by using the computational fluid dynamics(CFD) software.The influence of flow field shapes of grid,parallel and serpentine are analyzed and the pressure drop and velocity distribution in the three kinds of flow fields are studied.It shows that the flow field of serpentine is the best for the even distribution of fuel.Based on this,serpentine flow field models with different width(800,400,200 and 100 μm) are created.Simulations are taken to analyze the influence of distribution to cell performance and compared with experimental results,it shows that the optimal value of flow channel width is 200 ~400 μm.国家自然科学基金重点资助项目(60936003

禁止底拖网作业对珠江口香港海域底层鱼类的影响

【目的】研究禁止底拖网作业对珠江口香港海域底层鱼类的影响。【方法】根据2007-2009年及2014-2016年在珠江口香港海域进行的定点底拖网调查数据,分析该海域在禁止底拖网捕捞实施前后鱼类种类组成及生物量和生态多样性指数,评估5种典型底层鱼类资源的变化。【结果与结论】该海域捕获鱼类种类数在禁止底拖网作业后明显增加,鱼类种类数量从44种升至73种。种类丰富度指数D变化范围为:2007至2009年,4.937～5.711,2014至2016年,6.559～7.074;多样性指数H’变化范围为:2007至2009年,1.945～2.841,2014至2016年,2.220～2.381;均匀度指数J变化范围为:2007至2009年,0.539～0.776,2014至2016年,0.557～0.600。卵鳎Solea ovata、韦式羊舌鮃Arnoglossus waitei、尖嘴魟Dasyatis zugei这3种底层鱼类禁止底拖网实施后在数量(number)和生物量(biomass)上都增幅明显。不同站位数量和生物量的数值在“禁拖令”实施后也都有所增加,其中以站位2(大屿山以北,较靠近香..

底拖网作业对珠江口香港海域底层鱼类的影响

【目的】研究底拖网作业对珠江口香港海域底层鱼类的影响。【方法】根据2007-2009年及2014-2016年在珠江口香港海域进行的定点底拖网调查数据,分析该海域在禁止底拖网捕捞实施前后鱼类种类组成及生物量和生态多样性指数,评估5种典型底层鱼类资源的变化。【结果与结论】该海域捕获鱼类种类数在禁止底拖网作业后明显增加,鱼类种类数量从44种升至73种。种类丰富度指数D变化范围为:2007至2009年,4.937～5.711,2014至2016年,6.559～7.074;多样性指数H’变化范围为:2007至2009年,1.945～2.841,2014至2016年,2.220～2.381;均匀度指数J变化范围为:2007至2009年,0.539～0.776,2014至2016年,0.557～0.600。卵鳎Solea ovata、韦式羊舌鮃Arnoglossus waitei、尖嘴魟Dasyatis zugei这3种底层鱼类禁止底拖网实施后在数量(number)和生物量(biomass)上都增幅明显。不同站位数量和生物量的数值在"禁拖令"实施后也都有所增加,其中以站位2(大屿山以北,较靠近香港国际机场海域)增加最为显著

Study on extraction technology of volatile oil from cortex phellodendri by supercritical carbon dioxide

使用超临界二氧化碳技术对经过超声-微波处理过的黄柏中的挥发油进行萃取,并对萃取工艺进行响应面优化。在单因素预实验的基础上,以萃取压力、萃取温度、萃取时间为响应因素,黄柏挥发油的萃取量为响应值,根据中心组合(bOX-bEHnkEn)实验设计原理,采用三因素三水平的响应面分析法,确定各工艺条件对萃取量的影响,并用扫描电子显微镜(SEM)对萃取前、未超声-微波处理超临界萃取后及超声-微波处理超临界萃取后的黄柏进行比较观察,对萃取效果进行了微观解释。结果表明,经过超声-微波处理过的黄柏中的挥发油超临界二氧化碳萃取最佳工艺条件为:萃取压力为34MPA,萃取温度为41℃,萃取时间为66MIn,萃取率达6.03%。The supercritical carbon dioxide extraction of volatile oil from processed cortex phellodendri was optimized by response surface methodology(RSM).According to the principle of Box-Behnken central composite design,extraction pressure,extraction temperature,extraction time were chosen as response factors,extraction mass was chosen as response value,and a three-factor and three level central composite design was adopted to determine the influence of various technological conditions.Using SEM observed the cortex phellodendri before and after extraction,and explained the extraction effects from microcosmic aspect.The results showed that the optimum extraction conditions were as follows:extraction pressure 34MPa,extraction temperature 41℃,extraction time 66min,extraction yield was 6.03%.湖南省科技厅重大专项(2008FJ1007);2010年吉首大学大学生研究性学习与创新性实验计划项目(JSU-CX-2010-49

Photo-generated dinuclear {Eu(II)}2 active sites for selective CO2 reduction in a photosensitizing metal-organic framework

利用太阳光驱动CO2还原不仅可降低大气中CO2浓度，而且可以生成重要的化工原料，是缓解气候变暖和开发新能源的理想途径之一。然而如何制备高效光催化剂将CO2高选择性地转化为高附加值的化学产品极具挑战性。课题组巧妙地将具有催化活性的稀土簇合物与光敏配体组装在一起，合成了具有大孔结构的稀土Eu-Ru(phen)3-MOF催化剂，实现了可见光驱动的CO2到甲酸盐的高效选择性转化。研究表明，该材料光催化生成甲酸盐的反应速率可达到321.9 μmol h−1 mmolMOF−1，这是至今为止报道的光催化还原CO2转化为甲酸盐活性最高的MOFs催化剂。 该项研究工作由博士生闫志浩完成，博士生杜明浩参与部分表征工作；中国科学院大连化学物理研究所金盛烨研究员、刘俊学博士在瞬态光谱表征中给予了支持；我校化学化工学院汪骋教授在数据分析过程中给予大量帮助；理论计算由浙江工业大学庄桂林副教授完成。【Abstract】Photocatalytic reduction of CO2 is a promising approach to achieve solar-to-chemical energy conversion. However, traditional catalysts usually suffer from low efficiency, poor stability, and selectivity. Here we demonstrate that a large porous and stable metal-organic framework featuring dinuclear Eu(Ⅲ)2 clusters as connecting nodes and Ru(phen)3 -derived ligands as linkers is constructed to catalyze visible-light-driven CO2 reduction. Photo-excitation of the metalloligands initiates electron injection into the nodes to generate dinuclear {Eu(Ⅱ)} 2 active sites, which can selectively reduce CO2 to formate in a two-electron process with a remarkable rate of 321.9μmolh −1 mmol MOF −1 . The electron transfer from Ru metalloligands to Eu(Ⅲ)2 catalytic centers are studied via transient absorption and theoretical calculations, shedding light on the photocatalytic mechanism. This work highlights opportunities in photo- generation of highly active lanthanide clusters stabilized in MOFs, which not only enables efficient photocatalysis but also facilitates mechanistic investigation of photo-driven charge separation processes.We are grateful for the financial support from the 973 project (Grant 2014CB845601) of the Ministry of Science and Technology of China, the National Natural Science Foundation of China (Grants no. 21422106, 21673184, 21431005, 21721001, and 21390391) and the Fok Ying Tong Education Foundation (151013). We thank Dr. Wen-Ming Qin and the staffs from the BL17B beamline of National Center for Protein Sciences Shanghai at Shanghai Synchrotron Radiation Facility for assistance during data collection; we also thank Miss Ying-Zi Han for helpful measurement on ESI-MS. We also gratefully acknowledge Mr Xuefu Hu for helpful measurement on time-resolved PL and Miss Rong Chen for her assistance on CV measurement and analysis. 研究工作得到科技部（项目批准号：2014CB845601）、国家自然科学基金委（项目批准号：21422106、21673184、21431005、21721001、21390391）、教育部霍英东基金会青年教师基金（项目批准号：151013）等资助

生态旅游标准建设研究

回顾了生态旅游产生的背景,简要叙述了生态旅游发展的三个阶段。从生态旅游发展及其影响、生态旅游标准缺失的后果以及生态旅游标准体系的作用等方面论述了生态旅游标准体系建设的必要性。对比了国内外生态旅游标准体系建设现状,提出了我国的生态旅游标准建设应加快专业队伍组建,标准多元化和国际化等工作

The Design and Fabrication of a Micro Direct Methanol Fuel Cell

微型直接甲醇燃料电池(MICrO dIrECT METHAnOl fuEl CEll,μ-dMfC)具有发电效率高、环境污染少、安全、携带方便等优点,在小型民用电源和单兵携带电源上具有广泛的应用.讨论了微型直接甲醇燃料电池(MICrO dIrECT METHAnOl fuElCEll,μ-dMfC)的特点,研究了运用微机电系统(MICrO-ElECTrO-MECHAnICAl SySTEMS,MEMS)工艺,设计并且制作μ-dMfC的过程.主要是运用MEMS工艺制作μ-dMfC的流场板;制备膜电极(MEMbrAnE ElECTrOdE ASSEMbly,MEA);通过改进μ-dMfC的封装结构,采用聚二甲基硅氧烷(POlydIMETHylSIlOXAnE,PdMS)和金属夹具对μ-dMfC进行封装,有效地避免甲醇的渗漏;并且通过测试μ-dMfC的I-V特性,比较了不同封装结构下,μ-dMfC的电性能.实验结果表明,封装结构改进后的μ-dMfC,最大电流密度为14.82MA/CM2,最大输出功率为0.661MW.Micro direct methanol fuel cell(μ-DMFC)with the virtue of high power efficiency,few-environmental pollution,safety and portable has a great prospect of application in small civilian power and individual portable power.The characteristic of μ-DMFC(micro direct methanol fuel cell) is discussed.Then,with the process of micro-electro-mechanical systems(MEMS),the process that the μ-DMFC is designed and fabricated is researched.Firstly,the flow-field plate of μ-DMFC is fabricated by process of MEMS.Secondly,the membrane electrode assembly(MEA) is prepared.Then,the package structure of μ-DMFC is improved,the polydimethylsiloxanef(PDMS) and metal fixture are adopted to package the μ-DMFC,which avoids leakage of methanol effectively.Finally,the IV property of μ-DMFC is tested.The electrical property of μ-DMFC is compared on the different structure of package.The result shows that on the μ-DMFC of improved package structure,the maximum current density is 14.82 mA/cm2,and the maximum output power is 0.661 mW.国家自然科学基金重点项目(60936003

一种化学键合手性固定相及其制备方法

一种化学键合手性固定相及其制备方法，其特征在于使用糖肽类大环抗生素-去甲万古霉素作为手性选择剂，通过化学键合的方法将其键合于载体上。本发明适合于用作高效液相分离用色谱填料。所制得的固定相具有很强的手性识别能力和很好的稳定性能，可对多种不同类型的手性药物实现分离。带填