台风对沿海地区气溶胶光学特性的影响分析

利用CE317太阳辐射计对2005年第19号台风登陆前后期问(9月29 H至10月6日)进行观测实验,采用Langley法分析台风对中国大陆沿海地区气溶胶光学特性的影响.指出台风过后气溶胶光学特性明显发生改变,气溶胶大粒子数增多,小粒子数减小.气溶胶光学厚度、Angstr(o)m波长指数α和大气混浊度系数β为测量期间最低分别为0.132(550 nm处),0.861和0.079.同时利用实验期间APS3321空气动力学粒度仪分析的气溶胶单位体积数粗细质粒所占比重、气溶胶粒子尺度谱分布和实测的日际气溶胶粒子数浓度对实验分析结果.α,β进行对比,发现它们之间的一致性很好.     

电化学方法研究(phen)2Cu2+配合物与DNA的相互作用

用电化学循环伏安法和微分脉冲伏安法研究了1,10-邻菲咯啉铜配合物[（phen）2Cu^2＋]与小牛胸腺DNA（CTDNA）的相互作用。结果发现,在pH=7．4的三羟甲基胺基甲烷-盐酸缓冲溶液（Tris—HCl）中,（phen）2Cu^2＋配合物的铜离子在循环伏安图上呈现明显的准可逆氧化-还原波。当加入一定量的小牛胸腺DNA时,配合物（phen）,Cu^2＋的氧化和还原峰电流均有所下降。通过比较（phen）2Cu^2＋配合物中加入单链DNA和双链DNA后的氧化和还原峰电流下降的程度,前者比后者F降的程度小,可以得出（phen）2Cu^2＋配合物与小牛胸腺双链DNA的作用方式存在着插入式的沟槽结合模式。这个结论在本实验中由盐效应进一步得到证实。由此可知,（phen）2Cu^2＋配合物与小牛胸腺DNA形成了一种插入式的电惰性结合物,从而导致氧化还原峰电流下降。     

Tolman length of simple droplet: Theoretical study and molecular dynamics simulation

In 1949, Tolman found the relation between the surface tension and Tolman length, which determines the dimensional effect of the surface tension. Tolman length is the difference between the equimolar surface and the surface of tension. In recent years, the magnitude, expression, and sign of the Tolman length remain an open question. An incompressible and homogeneous liquid droplet model is proposed and the approximate expression and sign for Tolman length are derived in this paper. We obtain the relation between Tolman length and the radius of the surface of tension(R_s) and found that they increase with the Rs decreasing. The Tolman length of plane surface tends to zero. Taking argon for example, molecular dynamics simulation is carried out by using the Lennard–Jones(LJ) potential between atoms at a temperature of 90 K. Five simulated systems are used, with numbers of argon atoms being 10140, 10935, 11760, 13500, and 15360, respectively. By methods of theoretical study and molecular dynamics simulation, we find that the calculated value of Tolman length is more than zero, and it decreases as the size is increased among the whole size range. The value of surface tension increases with the radius of the surface of tension increasing, which is consistent with Tolman’s theory. These conclusions are significant for studying the size dependence of the surface tension.     

ZnO纳米棒在Si衬底上外延生长研究

运用热蒸发ZnO粉末法,以金做催化剂,分别在Si(100)和Si(111)两种基片上外延生长了ZnO纳米棒(样品分别标为1#和2#).通过X射线衍射(XRD)和扫描电子显微镜(SEM)分析,结合ZnO与Si的晶格结构特征,从理论上得出了两个样品的晶格匹配关系.1#样品:[0001]ZnO∥[114]Si,[0001]ZnO∥[1-1-4]Si,[0001]ZnO∥[11-4]Si,[0001]ZnO∥[1-14]Si,失配度为1.54;;2#样品:[0001]ZnO∥[111]Si,[21-1-0]ZnO∥[11-0]Si,[1-21-0]ZnO∥[1-01]Si ,[1-1-20]ZnO∥[011-]Si,失配度为18.12;.研究表明Si衬底对ZnO纳米棒生长方向具有调控作用.     

凝胶改性基底微藻细胞黏附特性及热力学分析

为强化微藻生物膜成膜过程中藻细胞与基底黏附,同时解决藻细胞残留造成的基底重复利用性差的问题,用聚N-异丙基丙烯酰胺(PNIPAAm)温缩型凝胶修饰基底.傅里叶红外光谱分析改性表面化学特性;结合微藻培养温度给出适宜藻细胞黏附的基底浸润特性;通过构建热力学模型,明晰温度对藻细胞与温缩型凝胶改性基底界面作用自由能的影响规律,...     

Improved filtered mesoscale interphase heat transfer model

Mesoscale structures that form in gas-solid flows considerably affect interphase heat transfer.A filtered interphase heat transfer model accounts for the effect...     

Joint Detection of Community and Structural Hole Spanner of Networks in Hyperbolic Space

Community detection and structural hole spanner (the node bridging different communities) identification, revealing the mesoscopic and microscopic structural properties of complex networks, have drawn much attention in recent years. As the determinant of mesoscopic structure, communities and structural hole spanners discover the clustering and hierarchy of networks, which has a key impact on transmission phenomena such as epidemic transmission, information diffusion, etc. However, most existing studies address the two tasks independently, which ignores the structural correlation between mesoscale and microscale and suffers from high computational costs. In this article, we propose an algorithm for simultaneously detecting communities and structural hole spanners via hyperbolic embedding (SDHE). Specifically, we first embed networks into a hyperbolic plane, in which, the angular distribution of the nodes reveals community structures of the embedded network. Then, we analyze the critical gap to detect communities and the angular region where structural hole spanners may exist. Finally, we identify structural hole spanners via two-step connectivity. Experimental results on synthetic networks and real networks demonstrate the effectiveness of our proposed algorithm compared with several state-of-the-art methods.     

气相色谱-质谱法测定回收环己烷中杂质含量

建立了气相色谱-质谱联用(GC-MS)测定环己烷中乙二醇二乙醚、邻甲基苯甲酸甲酯、五甲基二乙烯三胺、邻苯二甲酸二甲酯含量的方法.环己烷直接进样,通过毛细管柱DB-5,30m×0.25mm×0.5μm分离,由电子轰击源(EI)选择离子监测(SIM)模式下进行检测.结果表明,杂质的校准曲线相关系数均在0.9974-0.9996,相对标准偏差为4.6%-8.9%,回收率为93.3%-105.0%.     

离子交换聚合物固定三联吡啶钌电玫化学发光传感器的研究进展

将可电化学再生的电致化学发光试剂-三联吡啶钌固定于电极表面制备得到可再生的电致化学发光(ECL)传感器.综述了近年来使用离子交换聚合物膜固定三联吡啶钌ECL传感器的研究进展,简要介绍了不同离子交换聚合物的固定方法及其相关的应用情况.同时展望了该领域未来的发展方向和前景.     

Performance of La2O3/InAlN/GaN metal—oxide—semiconductor high electron mobility transistors

We report on the performance of La2O3/InAlN/GaN metal-oxide-semiconductor high electron mobility transistors(MOSHEMTs) and InAlN/GaN high electron mobility transistors(HEMTs).The MOSHEMT presents a maximum drain current of 961 mA/mm at Vgs = 4 V and a maximum transconductance of 130 mS/mm compared with 710 mA/mm at Vgs = 1 V and 131 mS/mm for the HEMT device,while the gate leakage current in the reverse direction could be reduced by four orders of magnitude.Compared with the HEMT device of a similar geometry,MOSHEMT presents a large gate voltage swing and negligible current collapse.