A novel open‐tubular capillary electrochromatography using carboxymethyl‐β‐cyclodextrin functionalized gold nanoparticles as chiral stationary phase

Enantioselective open tubular capillary electrochromatography with carboxymethyl‐β‐cyclodextrin conjugated gold nanoparticles as stationary phase was developed. This novel open tubular column was fabricated through layer‐by‐layer self‐assembly of gold nanoparticles on a 3‐mercaptopropyl‐trimethoxysilane‐modified fused‐silica capillary and subsequent surface functionalization of the gold nanoparticles through self‐assembly of 6‐mercapto‐β‐cyclodextrin. The 6‐mercapto‐β‐cyclodextrin was firstly synthesized and determined by extensive spectroscopic data. Scanning electron microscopy, energy dispersive X‐ray analysis spectroscopy, and electroosmotic flow experiments were carried out to characterize the prepared open tubular column. Then, the separation effectiveness of the open tubular column was verified by two pairs of ɑ‐tetralones derivatives enantiomers and two pairs of basic drug enantiomers (tramadol hydrochloride and zopiclone) as mode analytes. Factors that influence the enantioseparation were optimized, and under the optimized conditions, satisfactory separation results were obtained for the four enantiomers: compound A, compound B, tramadol hydrochloride, and zopiclone with resolutions of 3.79, 1.56, 1.03, 1.60, respectively. For the combination of gold nanoparticles and negatively charged carboxymethyl‐β‐cyclodextrin, the open tubular column exhibited wider separation range for neutral and basic drugs. Moreover, the repeatability and stability of the column were studied through the run‐to‐run and day‐to‐day investigations.     

Programmable Assembly of Nano-architectures through Designing Anisotropic DNA Origami Patches

Programmable assembly of nanoparticles (NPs) into well-defined architectures has attracted attention because of tailored properties resulting from coupling effects. However, general and precise approaches to control binding modes between NPs remain a challenge owing to the difficulty in manipulating the accurate positions of the functional patches on the surface of NPs. Here, a strategy is developed to encage spherical NPs into pre-designed octahedral DNA origami frames (DOFs) through DNA base-pairings. The DOFs logically define the arrangements of functional patches in three dimensions, owing to the programmability of DNA hybridization, and thus control the binding modes of the caged nanoparticle with designed anisotropy. Applying the node-and-spacer approach that was widely used in crystal engineering to design coordination polymers, patchy NPs could be rationally designed with lower symmetry encoded to assemble a series of nano-architectures with high-order geometries.     

开放式多功能实验教学综合管理系统的开发与实践

简要分析了高校开放式实验教学管理存在的问题,提出具有预约、预习和考核功能的多功能实验教学综合管理系统。该系统是由开放式网络教学管理系统、实验仿真系统和实验预习与考试测评系统三大模块组成,系统的使用使实验教学中心的管理规范化、科学化,合理整合了实验教学的设备资源和教师资源。经过长期实践,教学效果显著,对兄弟院校的开放式实验教学管理有一定的借鉴意义和示范作用。     

Resistive Switching Behavior in Amorphous Aluminum Oxide Film Grown by Chemical Vapor Deposition

The repeatable bipolar resistive switching phenomenon is observed in amorphous Al2O3 prepared by metalorganic chemical vapor deposition on ITO glass, with ITO as the bottom electrode and Ag as the top electrode. The crystal structure, morphology, composition and optical properties of Al2O3 thin films are investigated by x-ray diffraction, x-ray photoelectron spectroscopy, atomic force microscopy and ultraviolet-visible-infrared spectroscopy, respectively. The electronic character of Ag/Al2O3/ITO structure is tested by an Agilent B1500A. The device shows a typical bipolar resistive switching behavior under the dc voltage sweep mode at room temperature. The variation ratio between HRS and LRS is larger than nearly three orders of magnitude, which indicates the good potential of this structure in future resistive random access memory （ReRAM） applications. Based on the conductive filament model, the high electric field is considered the main reason for the resistive switching according to our measurements.     

Symplectic structure-preserving integrators for the two-dimensional Gross-Pitaevskii equation for BEC

Symplectic integrators have been developed for solving the two-dimensional Gross-Pitaevskii equation. The equation is transformed into a Hamiltonian form with symplectic structure. Then, symplectic integrators, including the midpoint rule, and a splitting symplectic scheme are developed for treating this equation. It is shown that the proposed codes fulfill the discrete charge conservation law. Furthermore, the global error of the numerical solution is theoretically estimated. The theoretical analysis is supported by some numerical simulations.     

形貌可控的Fe3O4纳米粒子的水热合成及磁性能研究

Fe3O4是一种重要的磁性材料.由于其独特的光、电、磁、热等性能而备受关注.在本文中,我们采用水热溶剂热法合成了Fe3O4磁性纳米粒子.利用X-射线衍射仪（XRD）、场发射扫描电子显微镜（FESEM）和振动样品磁强计（VSM）对产物的结构、形貌及磁性能进行了研究.结果表明,通过前驱物的适当选择,可以实现Fe3O4纳米粒...     

湿法消解-FAAS测定4省区藏药南寒水石中的钙及5种微量元素

使用湿法消解-FAAS测定4省区（西藏、青海、甘肃、四川）藏药南寒水石中钙及5种微量元素铁、锰、锌、铜、镁的含量。采用空气-乙炔火焰原子吸收光谱法对微量元素进行测定。该方法快速、准确,以期所测数据为藏药南寒水石实际用药及其质量标准的制定提供参考。     

具有较高级算子的两组分Camassa-Holm方程的柯西问题

讨论了具有高阶算子-(1-_x~2+_x~4)的两组分Camassa-Holm方程在Sobolev空间H~s,s>5/2中的柯西问题,利用构造逼近解方法证明了该方程解的局部适定性问题,同时应用能量估计及嵌入定理等方法得到了在给定初值条件下的爆破准则,并且进一步给出了具体的爆破速率.     

Near-invariant Tori on Exponentially Long Time for Poisson systems

This paper deals with the near-invariant tori for Poisson systems. It is shown that the orbits with the initial points near the Diophantine torus approach some quasi-periodic orbits over an extremely long time. In particular, the results hold for the classical Hamiltonian system, and in this case the drift of the motions is smaller than one in the past works.