SOLVABILITY FOR SECOND-ORDER MULTI-POINT BOUNDARY VALUE PROBLEMS ON A HALF-LINE

In this paper, we are concerned with the existence of a second-order differential equation with m-point boundary conditions on the half line. The existence results are proved by the Leray-Scha¨uder point theorem in a special Banach space. Green function plays an important role in the proof and its discussion is very interesting. The results obtained generalize those in the previous references.     

基于Matlab GUI的RLC仿真实验平台开发

针对目前RLC教学中存在的实验学时有限、实验设备不足的问题,借助Matlab中GUI的图形显示功能,开发了RLC电路特性仿真实验平台。介绍了仿真系统的结构、功能及构建方法。以RLC串联电路的暂态特性实验为例,详细阐述了仿真实验的方法和步骤。该系统操作方便,界面交互性良好,有助于提高学生学习的积极性,提高实验教学的效率。     

BiFeO3光伏效应研究进展

BiFeO3是一个典型的多铁性材料,是凝聚态物理研究领域的热点之一,在信息存储、自旋电子学以及传感器等方面具有诱人的应用前景.近两年来,多铁材料的光电特性引起了人们的广泛关注,许多问题有待于深入研究和探索.本文综述了近年来多铁材料BiFeO3在光伏领域的研究进展,讨论了铁电极化场、电极界面肖特基势垒以及铁电畴结构对BiFeO3光伏特性的影响规律.     

开放式创新型实验物理教学中心的建设与发展

对实验物理教学中心基础建设、教学质量监控管理、师资队伍建设以及教学环境建设等工作进行了探索与总结,项目的实施促进了大学生创新能力与素质的培养,确保了教学质量的稳步提高.     

Electrodeposition of platinum on tourmaline and application as an electrocatalyst for oxidation of methanol

A composite electrode of Pt nanoparticles coupled with tourmaline is prepared on glassy carbon (GC) disk electrode via electrodeposition. The nanocomposite of Pt/tourmaline is characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, X-ray powder diffraction, and transmission electron microscopy examinations linked with energy dispersive X-ray analysis. The electrocatalytic performance of the composite electrode (Pt/tourmaline/GC) is investigated in electrocatalysis oxidation of methanol at room temperature by cyclic voltammetry and chronoamperometry. It is indicated that Pt nanoparticles with size of ∼5 nm are uniformly assembled along the tourmaline particles and Pt exists in metallic and oxidated states confirmed by XPS. The results of electro-oxidation of methanol show that Pt/tourmaline catalyst is catalytically more active and stable than platinum-modified GC electrode, and the onset potential of Pt/tourmaline shifts 0.15 V to the negative side, and also the current density is significantly enhanced.     

超短脉冲激光对岩石的烧蚀作用研究

对干燥状态和浸水后的红砂岩、花岗岩、大理岩在不同超短脉冲激光入射频率和烧蚀发次等条件下的烧蚀情况进行了研究.结果发现,浸水后的岩石烧蚀质量损失明显大于干燥状态下的质量损失.同时质量损失与激光入射频率和烧蚀发次有着密切的关系.     

Structure and ultrafast carrier dynamics in n-type transparent Mo:ZnO nanocrystalline thin films

Transmitted laser propulsion in confined geometry using liquid propellant is proposed in this paper. The experimental results show that the coupling coefficient obtained by using carbonic ink is much higher than that using pure water due to the low breakdown threshold and high absorption. The influences of the focal condition and the mass of the liquid jet on the coupling coefficient are studied. The maxima of the coupling coefficient and the specific impulse obtained in the experiment are 1785.8 dyne/W and 19.3 s, respectively. The energy conversion efficiency is measured to be more than 50%. PACS 52.75.Di; 52.38.Mf; 79.20.Ds; 52.38.Dx; 52.40.Hf     

A new approach to synthesis of α-nitronyl nitroxide carboxylates. First metal complexes with α-imino nitroxide carboxylate

An effective procedure has been developed for the synthesis of the potassium salt of 4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl-3-oxide-2-carboxylic acid K(1). The salts of 4,4,5,5-tetramethyl-1-oxyl-4,5-dihydro-1H-imidazole-2-carboxylic acid X(2) are kinetically much more stable than K(1). Due to this, a series of heterospin complexes Cu(2)₂(CH₃OH)₂, Cu(2)₂(H₂O)₂, Cu(2)₂, Co(2)₂(CH₃OH)₂, Ni(2)₂(H₂O)₂, Ni(2)₂(py)₂, and Ni(2)₂(dipy) · H₂O were isolated. For K(2), Cu(2)₂(CH₃OH)₂, and Ni(2)₂(py)₂, crystal and molecular structure has been determined. For Cu(2)₂ and Ni(2)₂(bipy), cooperative magnetic ordering has been recorded at 16.6 and 4.6 K, respectively.     

Construction of Mesoporous Frameworks with Vanadoborate Clusters

A new porous vanadoborate was synthesized by employing the scale chemistry theory with the vanadoborate cluster V₁₀B₂₈. The twofold interpenetrated lvt network was assembled with zinc‐containing elliptical vanadoborate clusters and Zn polyhedra. The single lvt framework contains a three‐dimensional 38×38×20 ring channel system with the pore size (24.7×12.7 Å) reaching the mesoscale, thus indicating the possibility of constructing 3D ordered mesopores with vanadoborate clusters. The porosity of the SUT‐7 structure was confirmed by CO₂ adsorption of the as‐synthesized materials.