超亲水-超疏水组合壁面冷凝性能研究

本文通过水热法,结合气相沉积法和掩膜紫外光刻法,在玻璃基底上成功地制备了一种具有多尺度结构的超亲水-超疏水组合壁面,并对制备的具有不同润湿差异的组合壁面的冷凝效率进行了测试。结果表明壁面的冷凝效率取决于亲疏水区域的宽度和润湿性差异,其中当亲水区域宽度为0.80 mm,接触角约为0°,疏水区域宽度为0.95 mm,接触角为158°时,其冷凝效率相比光滑铜片的冷凝效率可以提高39%。进一步分析表明,液滴在极端润湿模式的组合表面的润湿分界线处具有较高的体积传输速率,且在超亲水区形成的连续微流通道加快了冷凝液滴快速排放,提高了整体表面的自更新能力。本文的研究,将为复杂润湿界面滴状冷凝的优化提供方向。     

基于发光机理提高掺铒硅基材料发光效率的几条途径

掺铒硅基发光材料可以用于制备光通信用光源、光纤放大器，更重要的是可能成为实现硅基光电子集成技术的重要途径，已成为研究的热点之一．文章讨论了掺铒硅及掺铒硅基材料的发光机理，指出了制约实用化方面存在的问题．从不同方面着重探讨了共掺氧对提高掺铒硅发光效率的作用．最后介绍了基于掺铒硅发光机理提高掺铒硅基材料发光效率的几种途径、目前存在的主要问题及研究进展．     

扰动情况下一类混沌系统的观测器同步

研究了存在外界扰动情况下一类混沌系统的同步问题，混沌系统非线性项无需满足输出反馈形式.首先对系统进行变换得到未受扰降价混沌系统，然后基于非线性观测器的思想构造同步观测系统实现了混沌同步，通过仿真证实了该方法的有效性. 关键词： 混沌系统 同步 观测器     

Synthesis and Properties of SEPS-g-PEO Copolymers with Varying Branch Lengths

Poly(ethylene oxide)(PEO) was controllably grafted from styrene-b-(ethylene-co-propylene)-b-styrene(SEPS) backbones by combining lithiation of styrenic units and living monomer-activated anionic ring-opening polymerization of ethylene oxide(EO)monomers with the aid of co-initiators triisobutyl aluminum.The as-synthesized SEPS-g-PEO copolymers were characterized by SEC,1 H-NMR,FTIR,SAXS,AFM and DSC.When the branch length is relatively small,increase of PEO fraction leads to the increase of the correlation length between neighboring hard domains,but the degree of correlation reduces.When the branch length is relatively large,the phase-separated structures become random both in terms of size and spatial correlation,and macro-phase separated structures appear.The crystallization behavior of the PEO branches can be effectively inhibited in SEPS-g-PEO,so no significant crystallization takes place until the fraction of PEO branches is 20.1 wt%,which greatly promotes the rapid delivery of hydrophilic drugs in the hot-melting pressuresensitive adhesives(HMPSAs) based on SEPS-g-PEO.Their cumulative release amount of a model drug could achieve 80%,more than twice the value in the HMPSAs based on linear PEO-containing styrenic block copolymers.     

牛血清蛋白单层膜诱导形成网状结构的羟基磷灰石

0引言近来利用生物矿化的方法来合成具有特殊结构的晶体材料成为材料合成的一个热点[1.2]。羟基磷灰石(HAP)作为一种生物材料,广泛地存在于人和动物的骨骼和牙齿中,是生物矿化的产物。在骨骼的修复、替代和仿生抗菌陶瓷薄膜中有重要的应用[3]。因此,利用生物矿化的方法合成具有     

固体酸催化合成4-羟基苯基-1′-O-D-吡喃葡萄糖苷

报道了一种简便易行的绿色合成4-羟基苯基-1′-O-D-吡喃葡萄糖苷(即熊果苷及其端基异构体)新方法,采用固体酸蒙脱石K-10或4A分子筛为催化剂,将四苄基保护的葡萄糖(2)或α-三氯乙酰亚胺酯糖给体(3)与氢醌直接进行糖基化反应,最高以86%的产率获得4-羟基苯基-2,′3,′4,′6′-四-O-苄基-1′-O-D-吡喃葡萄糖苷(4),进而脱除苄基保护,定量获得熊果苷及其端基异构体(1)。中间体(4)的结构经IR、MS、1H NMR及元素分析等测试技术进行了确认,化合物(1)的理化数据与文献值相同。     

2D NMR对Sarcophine所有^1H NMR和^1^3C NMR归属的指定

从中国南海软珊瑚Sarcophyton molle中分离得到大环二萜内酯Sarcophine(1)。本文利用^1H-^1H COSY，HMQC，HMBC等二维谱手段首次对Sarcophine所有^1H NMR、^1^3C NMR的信号归属进行了完全的指定。并第一次报道了其^1^3C NMR数据。     

Synthesis and Properties of SEPS-<Emphasis Type="Italic">g</Emphasis>-PEO Copolymers with Varying Branch Lengths

Poly(ethylene oxide) (PEO) was controllably grafted from styrene-b-(ethylene-co-propylene)-b-styrene (SEPS) backbones by combining lithiation of styrenic units and living monomer-activated anionic ring-opening polymerization of ethylene oxide (EO)monomers with the aid of co-initiators triisobutyl aluminum.The as-synthesized SEPS-g-PEO copolymers were characterized by SEC,1H-NMR,FTIR,SAXS,AFM and DSC.When the branch length is relatively small,increase of PEO fraction leads to the increase of the correlation length between neighboring hard domains,but the degree of correlation reduces.When the branch length is relatively large,the phase-separated structures become random both in terms of size and spatial correlation,and macro-phase separated structures appear.The crystallization behavior of the PEO branches can be effectively inhibited in SEPS-g-PEO,so no significant crystallization takes place until the fraction of PEO branches is 20.1 wt％,which greatly promotes the rapid delivery of hydrophilic drugs in the hot-melting pressuresensitive adhesives (HMPSAs) based on SEPS-g-PEO.Their cumulative release amount of a model drug could achieve 80％,more than twice the value in the HMPSAs based on linear PEO-containing styrenic block copolymers.     

Effects of Flow Rate Variation on SiCln （n 〈 3） Densities in SICl4 Plasmas

Radicals produced by the plasma enhanced chemistry vapour deposition technique in SiCl4 plasma are identified by mass spectrometry using our newly proposed straight-line fit method. Since flow rate is one of the most important parameters in depositing thin films, we present the effects of SiCl4 flow rate variation on SiCln （n 〈 3） densities. The experimental results demonstrate that Si and SiCln （n = 1, 2） densities decrease with increasing SiCl4 flow rate. After reaching the minimum values at a flow rate of 17 and 13sccm, respectively, Si and SiCln （n = 1, 2） densities slightly increase with further increase of flow rate to 20.5sccm. These results could be interpreted to which the depletion fraction of SiCl4 decreases and the residence time of SiCl4 molecule becomes shorter, with the increasing SICl4 flow rate. In order to obtain high-quality poly-Si films with high growth rate, it is better to use smaller flow rate of SICl4 source gas for depositing films.     

Synthesis and Crystal Structure of a New Mononuclear Cobalt（Ⅲ） Complex with 2,2＇-Dipyridylamine and Glycine as Ligands

A new mononuclear cobalt(Ⅲ) complex [Co(dpa)2(Gly)](ClO4)2·4H2O was synthesized by the reaction of Co2 , glycine (gly) and 2,2'-dipyridylamine (dpa) in a methanol-water solution, and its structure was characterized by IR, EA, ES-MS and X-ray structure analysis. The compound crystallizes in the monoclinic system, space group P21/n with a = 12.8795(2), b =13.2904(2), c = 19.1104(2) (A),β= 109.378(1)°, V= 3085.89(8) (A)3, Z = 4, Mr = 746.36, Dc = 1.606g/cm3,μ= 0.808 mm-1, F(000) = 1536, the final R = 0.0543 and wR = 0.1306 for 5393 independent reflections. The magnetic measurement of the compound at room temperature shows that it is diamagnetic and the cobalt ion is in low spin 3 oxidation state. ES-MS experiments show that the [Co(dpa)2(Gly)]2 cation is very stable in the methanol solution.