独立同分布随机环境中两性Galton-Watson分支过程灭绝概率的渐近行为

本文研究了独立同分布随机环境中的两性Galton-Watson分支过程,在上临界情形下,当k充分大时,qk≤ck<'-α>.     

Cu(II)-氨基酸-核苷酸三元配合物 II: Cu(II)-L-组氨酸、L-赖氨酸－5'-嘌呤核苷酸三元配合物

合成和表征了新的三元配合物: [Cu(L-His)(5'-AMP)]Cl2.4H2O,[Cu(L-His)(5'-GMP)]Cl2, [Cu(L-His)(5'-IMP)]Cl2.2H2O,[Cu(l-Lys)2(5'-GMP)]Cl2.6H2O, Na2[Cu(L-Lys)2(5'-GMPH_2)].6H2O,Na2[Cu(L-Lys)2(5'-GTPH_2)].6H2O, Na2[Cu(L-Lys)2(5'-IMPH_2)].10H2O. IR及NMR谱表明, 5'-嘌呤核苷酸以嘌呤碱基上的7-N原子与Cu(II)配位。在5'-嘌呤核苷酸形成的配合物中, 磷酸根不参与配位, 但是Na2.5'-GMPH-2和Na.5'-GTPH-2的磷酸根参与配位, 而Na2.5'-IMPH-2的磷酸根不参与配位。     

Perforated nanocap array: Facile fabrication process and efficient surface enhanced Raman scattering with fluorescence suppression

Recently, individual reduced-symmetry metal nanostructures and their plasmonic properties have been studied extensively. However, little attention has been paid to the approach to fabricating ordered reduced-symmetry metal nanostructure arrays. In this paper, a novel perforated silver nanocap array with high surface-enhanced Raman scattering (SERS) activity and fluorescence suppression is reported. The array is fabricated by electron beam evaporating Ag onto the perforated barrier layer side of a hard anodization (HA) anodic aluminum oxide (AAO) template. The morphology and optical property of the perforated silver nanocap array are characterized by an atomic force microscope (AFM), a scanning electron microscope (SEM), and absorption spectra. The results of SERS measurements reveal that the perforated silver nanocap array offers high SERS activity and fluorescence suppression compared with an imperforated silver nanocap array.     

基于温度的亚稳态氧化石墨烯性能

单片层氧化石墨烯由于其优异的物理化学性能,在离子和分子筛选、水脱盐和净化、气体分离、生物传感、质子导体、锂电池和超级电容等领域有巨大的潜在应用.然而普遍采用的Hummers法等化学、物理方法制备的氧化石墨烯是一种亚稳态材料.其最终形态的物理化学性能的转变与调控至关重要,亟需系统研究.本文采用恒温处理方法对氧化石墨烯亚稳态的转变进行调控,利用X射线光电子吸收谱、傅里叶红外吸收谱、扫描电子显微镜等方法检测氧化石墨烯含氧基团的含量、类型和形貌与温度的变化关系,并利用Zeta电位、紫外吸收谱、拉力测试分析温度对氧化石墨烯在转变过程中的溶液悬浮稳定性、光子能带、拉伸强度等性能的影响.所得定量测试结果发现,氧化石墨烯亚稳态的转变过程中存在环氧减少、羟基增加,以及整体含氧量下降的现象,而在此过程中氧化石墨烯的单片层形貌并无明显变化.但是这种结构的转变使得悬浮液黏稠度和亲水性大幅度增强,能带减小和拉伸强度增强效应明显.而当转变过程足够长时,氧化石墨烯的亲水性转而下降,并出现沉淀现象,表明羟基之间进一步发生了脱水转变.另外,本文还分析了恒温处理的时间、悬浮液的浓度对这种转变过程的影响.相关研究结果有利于理解亚稳态氧化石墨烯悬浮液随温度变化的性能转变,对氧化石墨烯具体应用有一定参考价值.     

水热法制备Ag3PO4/HAP复合光催化剂及其光催化性能（英文）

以牡蛎壳为原料,利用水热法合成高纯度的羟基磷灰石(HAP)载体,经磷酸银负载后,制备出纳米棒状Ag3PO4/HAP复合光催化剂。利用扫描电镜(SEM)、高分辨透射电镜(HRTEM)、X射线衍射(XRD)、X射线光电子能谱仪(XPS)对样品进行表征,并考察不同的制备因素对催化剂降解亚甲基蓝溶液性能的影响。结果表明,当质量比为1∶2时制备的1∶2-Ag3PO4/HAP催化剂的表现最为突出,在10 min时即可达到50%的降解率,在40 min时基本降解完全,是一种高效的复合光催化剂。     

Cu(II)-氨基酸-核苷酸三元配合物 II: Cu(II)-L-组氨酸、L-赖氨酸－5'-嘌呤核苷酸三元配合物

合成和表征了新的三元配合物: [Cu(L-His)(5'-AMP)]Cl2.4H2O,[Cu(L-His)(5'-GMP)]Cl2, [Cu(L-His)(5'-IMP)]Cl2.2H2O,[Cu(l-Lys)2(5'-GMP)]Cl2.6H2O, Na2[Cu(L-Lys)2(5'-GMPH_2)].6H2O,Na2[Cu(L-Lys)2(5'-GTPH_2)].6H2O, Na2[Cu(L-Lys)2(5'-IMPH_2)].10H2O. IR及NMR谱表明, 5'-嘌呤核苷酸以嘌呤碱基上的7-N原子与Cu(II)配位。在5'-嘌呤核苷酸形成的配合物中, 磷酸根不参与配位, 但是Na2.5'-GMPH-2和Na.5'-GTPH-2的磷酸根参与配位, 而Na2.5'-IMPH-2的磷酸根不参与配位。     

First-principles calculations of elasticity and thermodynamic properties of LaNi5 crystal under pressure

This paper investigates the equilibrium lattice parameters, heat capacity, thermal expansion coefficient, bulk modulus and its pressure derivative of LaNi 5 crystal by using the first-principles plane-wave pseudopotential method in the GGA-PBE generalized gradient approximation as well as the quasi-harmonic Debye model. The dependences of bulk modulus on temperature and on pressure are investigated. For the first time it analyses the relationships between bulk modulus B and temperature T up to 1000 K, the relationship between bulk modulus B and pressure at different temperatures are worked out. The pressure dependences of heat capacity C v and thermal expansion α at various temperatures are also analysed. Finally, the Debye temperatures of LaNi 5 at different pressures are successfully obtained. The calculated results are in excellent agreement with the experimental data.     

基于质谱分析动物组织代谢组学的样本制备策略

代谢组学主要研究生物体内小分子代谢物种类和数量的变化,能够准确的反映生命体终端和表型信息。尽管代谢组学技术进步主要得益于分析平台的发展,但是生物样本的制备作为其先决条件,近年来受到广泛的关注,尤其在质谱领域,而动物组织代谢组学因其制备策略的局限性正面临着在体液分析中未遇到的挑战,如提取流程非常耗时,有机溶剂大量使用等。本文结合近几年国内外研究人员发表的相关文献及大量的实验工作,综述了代谢组学组织样本的制备策略及发展方向,为进一步使用代谢组学研究动物生命科学提供参考。     

4,7-非对称二取代苯并噻二唑的合成

以邻甲苯胺为起始原料,经3步反应制得4-甲基-2,1,3-苯并噻二唑(1);1经溴代、水解和IBX选择性氧化制得系列4,7-非对称二取代苯并噻二唑砌块;通过砌块4-甲酰基-7-溴-2,1,3-苯并噻二唑与给电子基团的缩合或偶联反应,合成了具有4,7-非对称苯并噻二唑D-π-A型分子结构的新化合物4-甲酰基-7-N,N-二甲氨基-2,1,3-苯并噻二唑和4-甲酰基-7-[4-(N,N-二甲氨基)]苯基-2,1,3-苯并噻二唑,其结构经NMR和HR-MS表征.