Efficient Procedures of Sensitivity Analysis for Structural Vibration Systems with Repeated Frequencies

Derivatives of eigenvectors with respect to structural parameters play an important role in structural design, identification, and optimization. Particularly, calculation of eigenvector sensitivity is considered when the eigenvalues are repeated. A relaxation factor embedded in the combined approximations (CA) method makes it effective to the structural response at various modified designs. The proposed method is feasible after overcoming the defection of irreversibility of the characteristic matrix. Numerical examples show that it is easy to implement the computational procedure, and the method presented in this paper is efficient for the general linear vibration damped systems with repeated frequencies

Global existence of solutions for fuzzy second-order differential equations under generalized H-differentiability

AbstractIn this paper, we study the global existence of solutions for second-order fuzzy differential equations with initial conditions under generalized H-differentiability. Second derivative of the H-difference of two functions under generalized H-differentiability is obtained. Two theorems which assure global existence of solutions for second-order fuzzy differential equations are given and proved. Some examples are given to illustrate these results

Structured-Pump-Enabled Quantum Pattern Recognition

模式识别在信息安全等领域具有重要的应用。与基于计算机的传统方法相比，基于光学手段的模式识别技术由于具有并行高效的特点，因此越来越受到研究人员的青睐。陈理想教授团队通过光场调控的手段，创造性地采用空间结构光场代替常用的基模高斯光场来泵浦非线性晶体，从而有效操控自发参量下转换产生的纠缠双光子对的关联特性。 相关研究成果发表在国际物理学顶级期刊《物理评论快报》 (Physical Review Letters, DOI: 10.1103/PhysRevLett.122.123901)，并被编辑遴选为Editors’ Suggestion在Physical Review Letters主页推荐介绍，同时美国物理学会(APS)网站Physics也以“Face Recognition with Ghost Imaging”(基于鬼像的人脸识别)为题撰写Synopsis对该工作进行了全文亮点报道。 该论文的第一作者是物理科学与技术学院物理学系2016级博士研究生邱晓东同学，通讯作者为陈理想教授。【Abstract】We report a new scheme of ghost imaging by using a spatially structured pump in the Fourier domain of spontaneous parametric down-conversion for quantum-correlation-based pattern recognition. We exploit the mathematical feature of Laguerre-Gaussian mode’s Fourier transform to describe the pump-modulated formation of a ghost image. Of particular interest is the experimental demonstration of a quantum equivalence of a Vander Lugt filter, based on which the nonlocal spiral phase contrast for vortex mapping and quantum-correlation-based human face recognition are implemented successfully. The photons used for probing a test object, scanning the database, and producing a correlation signal can belong to three different light beams, which suggests some security applications where low-light-level illumination and covert operation are desired.This work is supported by the National Natural Science Foundation of China (Grant No. 91636109), the Fundamental Research Funds for the Central Universities at Xiamen University (Grant No. 20720160040), the Natural Science Foundation of Fujian Province of China for Distinguished Young Scientists (Grant No. 2015J06002), and the program for New Century Excellent Talents in University of China (Grant No. NCET-13-0495).该工作得到了国家自然科学基金重大研究计划、福建省半导体光电材料及其高效转换器件2011协同创新中心、厦门大学九江研究院和厦门大学校长基金的资助

Dynamic Characteristics of Mechanical Ventilation System of Double Lungs with Bi-Level Positive Airway Pressure Model

In recent studies on the dynamic characteristics of ventilation system, it was considered that human had only one lung, and the coupling effect of double lungs on the air flow can not be illustrated, which has been in regard to be vital to life support of patients. In this article, to illustrate coupling effect of double lungs on flow dynamics of mechanical ventilation system, a mathematical model of a mechanical ventilation system, which consists of double lungs and a bi-level positive airway pressure (BIPAP) controlled ventilator, was proposed. To verify the mathematical model, a prototype of BIPAP system with a double-lung simulators and a BIPAP ventilator was set up for experimental study. Lastly, the study on the influences of key parameters of BIPAP system on dynamic characteristics was carried out. The study can be referred to in the development of research on BIPAP ventilation treatment and real respiratory diagnostics

Output Feedback Stabilization for Stochastic Nonholonomic Systems under Arbitrary Switching

The output feedback controllers of stochastic nonholonomic systems under arbitrary switching are discussed. We adopt an observer which can simplify the design process. The designed control laws cause the calculation of the gain parameter to be very convenient since the denominator of virtual controllers does not contain the gain parameter. Finally, an example is given to show the effectiveness of controllers

In vitro and in vivo evaluation of folate receptor-targeting amphiphilic copolymer-modified liposomes loaded with docetaxel

Xiang Li1, Xin Tian2, Jing Zhang3, Xu Zhao1, Xiaohui Chen1, Youhong Jiang2, Dongkai Wang1, Weisan Pan11Department of Pharmaceutics, School of Pharmacy, Shenyang Pharmaceutical University, Shenyang; 2The Second Laboratory of Cancer Research Institution, The First Hospital of China Medical University, Shenyang; 3Key Laboratory of Modern Preparation of TCM, Ministry of Education, Jiangxi University of Traditional Chinese Medicine, Nanchang, ChinaBackground: The purpose of this study was to develop folate-poly (PEG-cyanoacrylate-co-cholesteryl cyanoacrylate) (FA-PEG-PCHL)-modified freeze-dried liposomes for targeted chemotherapy using docetaxel as a model drug.Methods: FA-PEG-PCHL was synthesized and its cytotoxicity was evaluated by CCK-8 assay in L929. Docetaxel-loaded liposomes modified by FA-PEG-PCHL were prepared by an organic solvent injection method and lyophilized to obtain freeze-dried FA-PEG-PCHL-docetaxel liposomes (FA-PDCT-L). Two carcinoma cell lines (MCF-7 and A-549 cells) were cultured with docetaxel solution, conventional docetaxel-loaded liposomes, or FA-PDCT-L, and the cytotoxicity and apoptosis was evaluated for each preparation. The uptake of the docetaxel preparations into MCF-7 cells was studied by confocal laser scanning microscopy. Liquid chromatography-mass spectrometry was used to study the pharmacokinetics and tissue distribution characteristics of the preparations.Results: The existence of an enlarged fixed aqueous layer on the surface of the liposomes was affirmed by zeta potential analysis. The entrapment efficiency and particle size distribution were almost the same as those of docetaxel-loaded liposomes. The drug release profile showed that the release rate was faster at higher molecular weight of the polymer. Compared with docetaxel solution and docetaxel-loaded liposomes, FA-PDCT-L demonstrated the strongest cytotoxicity against two carcinoma cell lines, the greatest intracellular uptake especially in the nucleus, as well as the most powerful apoptotic efficacy. In pharmacokinetic studies, the area under the plasma concentration-time curve of FA-PDCT-L was increased 3.82 and 6.23 times in comparison with the values for the docetaxel-loaded liposomes and docetaxel solution, respectively. Meanwhile, a lower concentration of docetaxel was observed for FA-PDCT-L in the liver and spleen, and a significantly higher concentration of FA-PDCT-L in tumors suggested that the presence of FA-PEG-PCHL on the liposomes resulted in greater accumulation of the drug in tumor tissue.Conclusion: Liposomes modified by FA-PEG-PCHL could be one of the promising suspensions for the delivery of antitumor drugs in cancer.Keywords: folate-poly (PEG-cyanoacrylate-co-cholesteryl cyanoacrylate), docetaxel, freeze-dried liposomes, tumor targetin