Ag厚度对其反射率的影响

采用射频磁控溅射方法在石英片上生长不同厚度Ag薄膜,测试了Ag膜反射率变化随厚度的变化关系,利用AfM和SEM分别研究Ag膜厚度对其表面粗糙度和形貌的影响。结果表明:Ag厚度在130nM以下时,随着厚度的增加,透射率急剧下降,其反射率逐渐增加;当厚度超过130nM时,透射率不再变化,由于表面rMS的增加使得散射损耗增大,使得其反射率随着厚度增加而减小

Optimization Electrode of GaN-Based Light-Emitting Diode

针对以蓝宝石为衬底的GaN基发光二极管出现的电流扩展不均的问题,采用有限元方法建立了GaN基发光二极管的三维网络模型,并对四种常见结构的器件进行数值模拟,发现影响二极管电流的因素不仅与发光二极管电极的位置有关,而且依赖于器件的结构参数。以电流扩展不均为指标确定出这四种器件中最佳的电极位置分布,同时对最佳电极位置分布的器件进行了结构参数优化,结果表明当p型金属层方块电阻与n型GaN的方块电阻接近时,电流扩展均匀性最好,且p-GaN的接触电阻和厚度越小,电流扩展越不均匀。A 3D networks model of GaN-based LED on sapphire substrate was built by finite element analysis to simulate the non-uniformity current spreading.Analog modeling was done on the four normal device structures,it was found that the factors effected the current of LED were the position of electrode and the parameters of device structure.Considering the practical structures of GaN-based LED,four LED designs were modeled and the optimal electrode distribution was obtained,meanwhile the structure parameters were optimized.It reveals that the smaller contact resistances and the thickness of p-GaN are,the more non-uniformity of current distribution is.国家自然科学基金(60276029);; 国家863计划(2004AA311020和2006AA032409);; 福建省科技项目和基金(2006H0092,A0210006,2005HZ1018

Preparation and Photoeletrochemical Performance of CdS Quantum Dot Sensitized ZnO Nanorod Array Electrodes

Corresponding author. Email: [email protected]; Tel: +86-592-2189663[中文文摘]采用连续式离子层吸附与反应法制备了CdS量子点敏化的ZnO纳米棒电极.应用扫描电子显微镜(SEM)、X射线衍射(XRD)和透射电子显微镜(TEM)对CdS量子点/ZnO纳米棒电极的形貌、晶型和颗粒尺寸进行了分析和表征;采用光电流-电位曲线和光电流谱研究了不同CdS循环沉积次数及不同沉积浓度对复合电极的光电性能影响.结果表明,前驱体浓度都为0.1mol·L-1且沉积15次敏化后的ZnO纳米棒阵列电极光电性能最好.与单纯的ZnO纳米棒阵列电极和单纯的CdS量子点电极相比,其光电转换效率显著提高,单色光光子-电流转换效率(IPCE)在380nm处达到76%.这是因为CdS量子点可以拓宽光的吸收到可见光区,并且在所形成的界面上光生载流子更容易分离.荧光光谱实验进一步说明了光电增强的原因是,两者间形成的界面中表面态大大减少,有利于减少光生电子和空穴的复合. [英文文摘]We sensitized CdS quantum dots on a ZnO nanorod array electrode by the successive ionic layer adsorption and reaction method.Scanning electron microscopy(SEM),X-ray diffraction(XRD),and transmission electron microscopy(TEM) experiments were performed to characterize the morphology,crystalline phase,and grain size of the CdS quantum dot sensitized ZnO nanorod array electrodes.The effect of CdS deposition cycle number and the precursor concentration were studied by photocurrent-potential characteristics and photocurrent spectra. The results showed that the best photoelectrochemical performance was obtained at 0.1 mol·L-1 for both Cd2+ and S2- after 15 cycles. Meanwhile, the composite films exhibited a remarkably enhanced photoelectric conversion efficiency compared with the ZnO nanorods array films and with CdS quantum dot electrodes. The monochromatic incident photon-toelectron conversion efficiency (IPCE) was as high as 76% at 380 nm. This may be attributed to the broad light harvesting capability of CdS and the efficient separation of photogenerated carriers on its interface. The reason for this enhancement was further confirmed by a photoluminescent experiment. The results showed that sensitization with CdS quantum dots reduced the recombination of electron and hole pairs resulting in an enhancement in the photocurrent.国家自然科学基金(20433040

Design and synthesis of hydrogenation nanocatalyst with synergetic multiple catalytic sites

基于催化剂多活性中心分工协同作用可活化两种或多种反应物,本研究工作以一种新的制备策略对贵金属-过渡金属-过渡金属氧化物催化剂进行合理设计,构筑金属与金属氧化物双活性中心。结果发现,贵金属负载于过渡金属/过渡金属氧化物(nM-TM/TMO)结构的催化剂在加氢反应中具有优异的催化活性。同时,热处理方法可有效调控催化剂微观结构,并对此构效关系进行了较为深入的研究。As synergic multiple active sites catalysts can theoretically activate two or more reactant or substrates simultaneously resulting in significantly increase of activity and stability of catalysts, we herein develop a novel catalysts preparation strategy to design and construct noble metal-transition metal-transition metal oxide(NM-TM/TMO) to form bi-active catalytic sites.The experimental results show that such a catalyst has excellent performance in catalytic hydrogenation, e.g.aromatic compounds hydrogenation as the case studies.It was also found that the nanostructure of catalyst can be tuned via thermal treatments, which are investigated and the relationship between structure and activity is explored to some extent.国家自然科学基金项目(20973140;201106118;21303140)~

基于递归系统模型的宫颈癌患者住院费用影响因素分析

目的分析宫颈癌患者住院费用的影响因素,为控制住院费用提供依据。方法收集厦门市某三甲医院2012 -; 2014年入院接受治疗且信息完整的宫颈癌患者的一般情况和住院费用等资料,通过递归系统模型分析各因素的直接与间接效应,计算总效应,找出费用控制的关; 键性因素。结果共纳入524例宫颈癌患者,其中医保患者占49.8%,首诊年龄的中位数为48岁,住院天数的中位数为28天,总费用的中位数为43841; .06元。支付方式、转移情况对总费用仅有直接效应,同时治疗其他疾病、MRI检查仅有间接效应;; 临床分期、治疗方案、手术方式既有直接效应又有间接效应;; 治疗方案的总效应值最大。结论宫颈癌住院费用受到多个因素的直接效应、间接效应、直接和间接效应的影响,其中以治疗方案的影响最大。可通过规范化制定治疗; 方案控制宫颈癌的住院费用。厦门大学大学生创新项目基

Damage to mangroves from extreme cold in early 2008 in southern China

通讯作者Author for correspondence (E-mail: [email protected])2008年初,我国南方19个省经历了50年一遇的持续低温雨雪冰冻天气。极端气候对华南沿海各省的红树林区造成不同程度的危害。2008年3月,在我国南方各省红树林区的10个代表性地点,对这次寒害造成的红树植物伤害程度进行了系统的调查。结果表明:冬季低温对红树林的影响极为显著,特别是在低纬度的海南、广西和广东湛江,由于极端低温正值夜间退潮,对红树林的影响更为显著;在纬度较高的福建,本地红树种类秋茄(Kandelia obovata)、桐花树(Aegiceras corniculatum)和白骨壤(Avicennia marina)及引种的木榄(Bruguiera gymnorrhiza)等,由于长期适应于冬季较低的气温或在种植前经过抗寒锻炼,具有较强的抗寒能力。各地主要红树植物中,广布种秋茄、桐花树和白骨壤最为耐寒,其耐寒性均大于红树科的木榄、海莲(Bruguiera sexangula)和红海榄(Rhizophora stylosa)。海桑(Sonneratia caseolaris)对温度的敏感性最强,抗寒能力最低,因此,即使在其原产地海南也受到较为严重的寒害,在纬度更高的引种地出现大面积受害甚至全部死亡,而从孟加拉国引种的无瓣海桑(Sonneratia apetala)却显示出一定的抗寒能力。同一地点的红树植物幼苗的抗寒能力低于大树。此次寒害也造成了苗圃场的种苗大量死亡,成熟的植株提前落花落果,这势必会影响后继一两年内红树林的自然更新和人工造林。因此,在未来红树林造林或人工引种中,一定要考虑到红树植物的抗寒能力。国家自然科学基金(30671646和30700092);厦门大学“闽江学者”启动基

Research Process of InGaN/GaN Multiple-quantum-well Solar Cells

IngAn/gAn量子阱太阳能电池在扩宽氮化物半导体太阳能电池光谱响应和提高电池效率方面有较大优势,近几年来受到了广泛关注.本文回顾了IngAn/gAn量子阱电池发展历程,论述了量子阱区域结构设计和外界条件对IngAn/gAn量子阱电池效率的影响,介绍了为提高IngAn/gAn量子阱电池效率所进行的关键工艺技术研究,总结了实现高效IngAn/gAn量子阱电池需要解决的问题和可能解决方案,为高效IngAn/gAn量子阱电池的实现提供参考.InGaN/GaN multiple-quantum-well(MQW)solar cells have recently attracted significant attention as a hopeful candidate for expanding spectral responses and improving efficiencies during past few years.In this paper,the research progress of InGaN/GaN MQW solar cells is reviewed.The effect of quantum-well-region designs and external conditions on the efficiency of InGaN/GaN quantum-well solar cell is discussed.In addition,critical processes of improving efficiencies of InGaN/GaN MQW solar cells are introduced.Finally,difficulties and solutions associated with improving efficiencies of InGaN/GaN MQW solar cells are summarized,offering useful references for achieving high-efficiency InGaN/GaN MQW solar cells.国家自然科学基金(61404059;61274052

褪黑素对重离子辐射损伤小鼠肺的防护作用研究

目的探讨褪黑素(melatonin,MLT)对重离子辐射损伤小鼠肺的防护作用。方法预先给小鼠腹腔注射10mg/kg的MLT,1h后给予0、0.5、1.0、2.0及4.0Gy的全身12C6+束均匀照射,剂量率约1.4Gy/min,辐射后8h,检测辐射损伤小鼠肺组织的SOD活性和MDA、GSH含量,并通过单细胞凝胶电泳技术检测辐射损伤小鼠肺细胞的拖尾长度和尾距。结果和单纯辐射组相比,10mg/kg的MLT腹腔注射能有效抑制重离子辐射引起的小鼠肺组织SOD活性降低、GSH含量下降和MDA含量提高;同时,MLT还能使受损小鼠肺细胞的拖尾长度和尾距显著降低,且都存在剂量效应关系。结论MIT对重离子全身辐射所致小鼠的抗氧化系统有一定的激活效应,对辐射损伤有一定的防护作用,这可能与对抗膜脂质过氧化、清除自由基及其减轻DNA损伤有一定的关系

合肥市夏季流浪猫流浪狗行为时间分配的初步研究

城市中不断增多的流浪猫、狗日益引起人们的关注。2008年7月10～18日,在合肥市区的街道和居民区等区域,对流浪猫、狗进行了调查和行为研究。流浪猫、狗每天的主要活动是觅食和休息。其中流浪狗全天行为时间分配中,休息行为占35.71%,觅食行为占10.36%,觅食活动（觅食、走动、跑动和观望）约占48.74%,安全防护（警戒、威吓、叫吠和逃逸）约占10.23%;而流浪猫休息行为占32.04%,觅食行为占7.35%,觅食活动占43.88%,安全防护占16.52%。流浪狗1 d有3次觅食高峰,主要集中在清晨;流浪猫的主要觅食活动在傍晚后

无线传感器网络中的组划分算法

以增加网络生命期为目的设计组划分算法,考虑了传感器网络中各个组长节点的组合理性、平均组能耗和组间负载平衡等因素,对初始的组划分进行了分析和优化处理而得到一个平均组能耗小并且组间负载平衡的组划分,有效地延长了网络生命期