多功能磁性纳米粒的合成、修饰及生物医学应用

多功能磁性纳米粒由于其独特的性质而受到广泛的关注。磁性纳米粒可以与荧光探针、生物靶向分子或抗肿瘤药物等相结合实现磁性纳米粒的多功能化,因此在多模式成像、癌症的靶向诊断与治疗中有较好的应用前景。本文介绍了磁性纳米粒的合成以及多功能磁性纳米粒的构建方法,重点介绍了核壳型、哑铃型和组合杂化型三种不同类型多功能磁性纳米粒的合成方法。多功能磁性纳米粒通常具有粒径小、超顺磁性以及荧光等独特性质,在此基础上对纳米粒表面进行稳定化和靶向性修饰后即可在多模式成像、特异性靶向药物输送、基因转染等生物医学领域得到应用。最后指出了当前研究中需要解决的问题。     

Ekeland's inverse function theorem in graded Fréchet spaces revisited for multifunctions

In this paper, we present some inverse function theorems and implicit function theorems for set-valued mappings between Fréchet spaces. The proof relies on Lebesgue's Dominated Convergence Theorem and on Ekeland's variational principle. An application to the existence of solutions of differential equations in Fréchet spaces with non-smooth data is given.     

Hammerstein integral inclusions in reflexive Banach spaces

In this paper we examine multivalued Hammerstein integral equations defined in a separable reflexive Banach space. We prove existence theorems for both the ``convex' problem (the multifunction is convex-valued) and the ``nonconvex' problem (the multifunction is not necessarily convex-valued). We also show that the solution set of the latter is dense in the solution set of the former (relaxation theorem). Finally we present some examples illustrating the applicability of our abstract results.

     

The sharp lower bound for the first positive eigenvalue of a sub-Laplacian on a pseudo-Hermitian manifold

This paper studies, using the Bochner technique, a sharp lower bound of the first eigenvalue of a subelliptic Laplace operator on a strongly pseudoconvex CR manifold in terms of its pseudo-Hermitian geometry. For dimensions greater than or equal to , the lower bound under a condition on the Ricci curvature and the torsion was obtained by Greenleaf. We give a proof for all dimensions greater than or equal to . For dimension , the sharp lower bound is proved under a condition which also involves a distinguished covariant derivative of the torsion.

     

序Banach空间中保序集值映射的不动点定理及应用

本文引进保序集值映射,弱上半连续集值映射等概念。然后讨论了保序集值映射不动点,最小不动点的存在问题,改进和推广了[2～4]中的几个主要结论。同时,我们把[1]中的主要结果从(单值)混合单调映射推广为混合单调集值映射,得到了更一般性的结论。     

Multifunction switching by a flat structurally tunable acoustic metasurface for transmitted waves

In this paper a flat structurally tunable acoustic metasurface is constructed based on the helical unit cell. The length of the acoustic channel can be tuned by the screw-in depth of the helix. Accordingly, the wave phase for the transmitted acoustic wave can be tuned and the wavefront can be manipulated. Then multifunctions such as anomalous refraction, point focusing, beam focusing and self-bending can be realized and switched just by screwing in or out the helixes. At the same time, the broadband operating frequency is also realized. The experiments for anomalous refraction and point focusing are also performed, and the results show that the designed metasurface is effective. The present studies have important applications in dynamic manipulation of acoustic waves by metasurfaces.     

NdxLa2−xCaB10O19: Synthesis and characterization

Solid solutions of Nd_xLa_2−xcaB₁₀O₁₉ with different Na³⁺ concentration have been synthesized by substituting Nd ³⁺ for La³⁺ in La₂CaB₁₀O₁₉ Powder X-ray diffraction analysis shows that Nd³⁺ is easy to incorporate into the crystal. Single crystal nd_xLa_2−xCaB₁₀O₁₉ (NLCB) in centimeter size has been grown by Kyropoulos method. The crystal has strong absorption around 580nm and 805nm. The fluorescence spectra indicate that there is an energy transition at 1.06μm. And the SHG of NLCB is about the twice as that of KDP. These favorable features make NLCB a candidate for laser NLO multifunctional materials.     

函数强伪凸性与映射强伪单调性

1　引　　言Schaible在[1]中引入七类单调映射,并证明对其中六类,函数的某种广义凸性都和相应的梯度单调性等价,只有函数强伪凸和梯度强伪单调的等价性是否成立作为公开问题.其后,Schaible又在[2]中通过一个例子否定了两者的等价性,并引入了较弱的函数强伪凸和映射强伪单调的概念,在函数二次可微的条件下证明了函数强伪凸和梯度强伪单调等价.我们将引入强于[2]中概念的强伪凸和强伪单调性,对给出的定义,不附加条件便可保证函数强伪凸性和梯度强伪单调性等价.同时,对[2]中的一个错误予以指出,并给出正确的反例.还就[1]中问题给出远比[2]中简…     

LF广义上(下)几乎半连续多值映射及其性质

借助广义开集引入LF广义上（下）几乎半连续和广义几乎连续多值映射等概念,得到其若干等价条件,并研究了LF广义上（下）几乎半连续多值映射及其闭包间的关系。     

Uniqueness of smooth radial balanced metrics on the disc

We show that the usual Poincaré metric is the only radial balanced metric on the disc with not too wild boundary behaviour. Additionally, we identify explicitly all radial metrics with such boundary behaviour which satisfy the balanced condition as far as germs at the boundary are concerned. Related results for the annulus and the punctured disc are also established.