具有磁性-多色发光-热性能的MWCNTs负载NaGdF4:Tb3+,Eu3+多功能复合纳米材料

采用液相法成功制备了MWCNTs负载NaGdF_4∶Tb~(3+),Eu~(3+)纳米粒子的磁光热多功能复合纳米材料,并用XRD,SEM和EDS对其结构、组成和形貌进行了表征,结果表明:NaGdF_4∶Tb~(3+),Eu~(3+)纳米粒子为六方晶相,形貌为球形且尺寸分布均匀,直径大约为25 nm,并且均匀的包覆在MWCNTs的表面;通过PL,VSM和HTC对复合纳米材料的发光性能,磁性能和光热转换性能进行了表征,采用MTT法对多功能复合纳米材料的生物相容性进行了评估,结果表明:MWCNTs-NaGdF_4∶Tb~(3+),Eu~(3+)复合纳米材料具有良好的多色发光性能、磁性能、光热转换性能、低的毒性和良好的生物相容性。该种磁光热多功能复合纳米材料在生物标记、生物成像、肿瘤诊疗等领域有着广泛的应用前景。     

石墨烯基人工智能柔性传感器

皮肤是人体最大的器官,能够感知和应对复杂的环境刺激。以石墨烯作为核心部件制备的柔性传感器具有很强的刺激感知能力,可以模拟人体皮肤的柔韧性和拉伸性,是目前最具商业化潜力的可穿戴传感技术。本文首先介绍了传感器的压阻式、电容式、压电式、晶体管式等不同工作机制和评价其性能的如灵敏度、检测范围、响应速度等参数,总结了石墨烯的优点和制备方法。结合本课题组在石墨烯复合聚苯胺、银纳米粒子、碳纳米管和量子点等构建多功能石墨烯基柔性传感器的研究基础,从检测对象的种类出发,重点阐述了石墨烯基柔性传感器在检测压力、应变、温度、湿度、化学分子、生物分子和气体等单一目标物的性能以及石墨烯基多功能柔性传感器的应用。最后,对石墨烯基柔性传感器的未来发展方向做了展望。     

Convergence of a Block Coordinate Descent Method for Nondifferentiable Minimization

We study the convergence properties of a (block) coordinate descent method applied to minimize a nondifferentiable (nonconvex) function f(x ₁, . . . , x _N ) with certain separability and regularity properties. Assuming that f is continuous on a compact level set, the subsequence convergence of the iterates to a stationary point is shown when either f is pseudoconvex in every pair of coordinate blocks from among N-1 coordinate blocks or f has at most one minimum in each of N-2 coordinate blocks. If f is quasiconvex and hemivariate in every coordinate block, then the assumptions of continuity of f and compactness of the level set may be relaxed further. These results are applied to derive new (and old) convergence results for the proximal minimization algorithm, an algorithm of Arimoto and Blahut, and an algorithm of Han. They are applied also to a problem of blind source separation.     

Domains in complex surfaces with non-compact automorphism groups

Let X be an arbitrary complex surface and D a domain in X that has a non-compact group of holomorphic automorphisms. A characterization of those domains D that admit a smooth, weakly pseudoconvex, finite type boundary orbit accumulation point is obtained.     

Boundary jets of holomorphic maps between strongly pseudoconvex domains

In this paper we consider jets taken at a fixed boundary point of germs of holomorphic diffeomorphisms which send one strongly pseudoconvex domain into another. We completely describe possible first and second jets and conditions of extremality in terms of the Chern-Moser normal forms of the domains.     

一种简单的方法制备SERS基底用于染料分子的富集、降解与检测

用一种简单的方法制备银纳米粒子, 研究了此纳米粒子作为SERS基底、吸附剂和光催化剂的多功能性。在光照条件下研究其对染料分子的光催化性能, 用紫外光谱和表面增强拉曼光谱对整个光催化过程进行动态跟踪检测, 实验结果表明染料分子光照条件下确实被催化降解了。本实验不仅合成了多功能的基底材料, 还赋予了表面增强拉曼光谱新的应用价值, 为光催化实验提供了新的动态跟踪检测方法。     

随机二阶多值周期问题解的存在性

本文研究了随机二阶多值周期问题解的存在性,在非常一般的假定下建立了凸和非凸问题解的存在性定理,并给出了在随机周期反馈控制系统中的应用．     

Multiplier ideal sheaves in complex and algebraic geometry

The application of the method of multiplier ideal sheaves to effective problems in algebraic geometry is briefly discussed. Then its application to the deformational invari-ance of plurigenera for general compact algebraic manifolds is presented and discussed. Finally its application to the conjecture of the finite generation of the canonical ring is explored, and the use of complex algebraic geometry in complex Neumann estimates is discussed.     

A taxonomy of best-reply multifunctions in 2×2×2 trimatrix games

This paper provides an overview of the various shapes the best-reply multifunctions can take in 2×2×2 trimatrix games. It is shown that, unlike in 2×2 bimatrix games, the best replies to the opponents’ pure strategies do not completely determine the structure of the Nash equilibrium set.