红树植物内生真菌Penicillium sp.中一个醌类化学成分的研究

利用各种层析手段(反相ODS健合硅胶、葡聚糖凝胶LH-20柱层析等),从红树植物内生真菌Penicil-liumsp.的发酵液中分离纯化了1个醌类化合物,通过各种波谱实验(1D-NMR,2D-NMR以及ESIMS)确定其结构为:5-甲氧基-11,12,18,19-四羟基蒽醌(1)。     

实施“微专题”,促进深度学习

本文针对当前高中数学深度学习的问题,解读了深度学习的内涵,并指出深度学习的重要意义.文章针对如何实施深度学习展开探究,笔者利用微专题探讨了具体的做法,促进了学生深度学习,并能有效提升学生的核心素养.     

“互联网+”背景下高校党建工作信息化建设路径研究

随着“互联网+”技术的不断深入发展,势必给高校党建工作信息化带来机遇和挑战?目前,高校党建工作信息化存在着认识和重视层度不够,基层党务工作者的信息化水平和能力不够,技术功能开发应用不够,智慧化平台的开发和应用不够等问题?因此,要从顶层设计?数据梳理?队伍建设和平台开发等方面入手,创新“互联网+”党建工作信息化路径,从而...     

2,5-环己二烯酮类的固相光化学(Ⅱ)

本文报道了2,4,6-三叔丁基-4-甲氧基-2,5-环己二烯酮的固相光化学反应,所得三种产物的比率随温度而变化,而液相光化学反应与温度无关。用带有NaNO₂滤色液的光照射该化合物,几乎得到100％的列米酮。在列米酮中加入少量萘的固相光化学反应所得产物的比率随萘量而变化。     

稀土焦绿石化合物Er-2Fe4/3W2/3O7的高温高压多形转变

F.Basile和M.A.Subramanian等人在常压高温下合成出变形的焦绿石化合物Er₂Fe_4/3W_2/3O₇,并用X射线粉末衍射法定出其结构属六方晶系。但对这种化合物的高温高压结构研究未见文献报导。我们在高压高温下进行了这种化合物的多形转变的研究。     

分布式光纤传感器测量数据可靠性分析方法

分析了分布式光纤传感器测量结果的可靠性,提出从应变系数和温度系数标定到分布式光纤传感器物理量测量以及结果评价的方法,设计了分布式光纤传感器的应变系数和温度系数标定装置,同时分析了应变标定装置的不确定度来源,采用基于光频域反射技术的分布式光纤解调仪进行了实验验证.应变标定范围为-5000με?5000με,温度标定范围为...     

新月菱形藻(Nitzschia closterium)制备参数对藻球性质及去氮磷效果的影响

为了制备出高效的固定化藻球, 完善固定化藻球的制备工艺, 以新月菱形藻为藻种, 采用褐藻胶包埋技术和单因子试验, 研究了不同褐藻酸钠质量分数(2.0％、2.5％、3.0％)和不同溶剂(海水、蒸馏水、NaCl溶液)对藻球形状、强度、传质性、去除氮磷效果及藻细胞生长的影响. 结果表明: 不同褐藻酸钠质量分数对藻球形状影响显著(P<0.05), 褐藻酸钠质量分数为2.0％和2.5％时藻球呈球形, 为3.0％时藻球呈不规则的水滴形; 不同溶剂种类对藻球形状则无影响. 不同褐藻酸钠质量分数对藻球强度影响显著(P<0.05), 随着褐藻酸钠浓度的增加, 藻球强度逐渐增强; 不同溶剂对藻球强度的影响显著(P<0.05), 影响大小的排序为海水>NaCl>蒸馏水. 不同褐藻酸钠质量分数和不同溶剂对藻球传质性影响显著(P<0.05), 随着褐藻酸钠浓度的增加, 藻球传质性也逐渐增强; 溶剂对传质性影响的强弱排序为海水>NaCl>蒸馏水; 不同褐藻酸钠质量分数和不同溶剂对固定化藻球藻细胞生长及去氮磷效率影响显著(P<0.05), 其中以3.0％褐藻酸钠+海水的藻细胞生长最快, 去除氮磷效率最佳.     

物联网信息感知与交互技术研析

随着物联网受到各国学术期刊和媒体新闻的频繁报道和关注,说明物联网已成为信息技术的另一个发展领域。物联网信息感知与交互技术也受到更多的开发和研究。以信息交互为服务基础、信息感为基本功能实现物联网"全面感知"信息。本文分析了物联网信息感知和交互技术研究方向,并指出了研究过程中可能遇到的问题,展示了物联网的发展前景。     

MIMO-OFDM系统同步技术研究进展

多输入多输出正交频分复用(MIMO-OFDM)系统对定时偏移和频率偏差极其敏感,并且对时间同步精度要求极高。分析比较了29种具有代表性的MIMO-OFDM系统同步算法的优缺点,指出针对数据辅助类的同步方法,采用共轭、取反等特性构造优良正交性的训练序列是提高时间同步性能的关键,可在时域进行频偏估计和降低参数维数来降低系统计算复杂度;针对非数据辅助类的同步方法,构造计算复杂度较低的代价函数是提高频率同步性能的关键,这些都是MIMO-OFDM系统同步方法值得研究的方向。     

基于SiO2溶胶的稳定性的Cu/SiO2催化体系在化学机械抛光中的应用研究

There is a lot ofhydroxyl on the surface ofnano SiO2 sol used as an abrasive in the chemical mechanical planarization （CMP） process, and the chemical reaction activity of the hydroxyl is very strong due to the nano effect. In addition to providing a mechanical polishing effect, SiO2 sol is also directly involved in the chemical reaction. The stability of SiO2 sol was characterized through particle size distribution, zeta potential, viscosity, surface charge and other parameters in order to ensure that the chemical reaction rate in the CMP process, and the surface state of the copper film after CMP was not affected by the SiO2 sol. Polarization curves and corrosion potential of different concentrations of SiO2 sol showed that trace SiO2 sol can effectively weaken the passivation film thickness. In other words, SiO2 sol accelerated the decomposition rate of passive film. It was confirmed that the SiO2 sol as reactant had been involved in the CMP process of copper film as reactant by the effect of trace SiO2 sol on the removal rate of copper film in the CMP process under different conditions. In the CMP process, a small amount of SiO2 sol can drastically alter the chemical reaction rate of the copper film, therefore, the possibility that Cu/SiO2 as a catalytic system catalytically accelerated the chemical reaction in the CMP process was proposed. According to the van＇t Hoff isotherm formula and the characteristics of a catalyst which only changes the chemical reaction rate without changing the total reaction standard Gibbs free energy, factors affecting the Cu/SiO2 catalytic reaction were derived from the decomposition rate of Cu （OH）2 and the pH value of the system, and then it was concluded that the CuSiO3 as intermediates of Cu/SiO2 catalytic reaction accelerated the chemical reaction rate in the CMP process. It was confirmed that the Cu/SiO2 catalytic system generated the intermediate of the catalytic reaction （CuSiO3） in the CMP process through the removal rate of copper film, infrared spectrum and AFM diagrams in different pH conditions. FinalLy it is concluded that the SiO2 sol used in the experiment possesses stable performance; in the CMP process it is directly involved in the chemical reaction by creating the intermediate of the catalytic reaction （CuSiO3） whose yield is proportional to the pH value, which accelerates the removal of copper film.