Evaluating π-π-Interactions as a Method for Isolation of Polycyclic Aromatic Hydrocarbons from Solution

The polycyclic aromatic hydrocarbon (PAH), chrysene, was linked to the solid support TentaGel S-NH₂ via a linker by means of synthesis. The resulting product 4-(chrysene-1-yloxy)-N-(TentaGel S)butanamide (4) was then evaluated for its ability to isolate PAHs from solution by means of π-π-interactions.     

斜群代数的倾斜维数

基于倾斜理论引入了倾斜投射模的概念.讨论了它的基本性质,并进一步引入了模的倾斜投射维数以及Artin代数的倾斜整体维数.令G是有限群,研究了Artin R-代数Λ和斜群代数ΛG的倾斜整体维数之间的关系,得到等式t.gl.dim(Λ)=t.gl.dim(ΛG).     

基于知识图谱技术的风电数据管理与应用研究

随着我国风电领域的发展,行业内产生的相关数据在来源和数量上都达到了一个新的高度.这些数据被分散在各个业务系统中,若能对其进行统一管理并应用,则对行业具有积极作用.提出了一种用知识图谱管理风电数据的方法.首先,从多源风电数据中抽取出实体、关系、属性等知识图谱元素.在此过程中,分别给出了针对结构化与非结构化数据的抽取方法....     

基于混合型Chopper电路的MMC-UPFC故障渡越方案

当交流系统发生短路时,基于模块化多电平控制器的统一潮流控制器(MMC-UPFC)串、并联侧MMC均会受到故障冲击,存在两侧换流器过流闭锁,MMC-UPFC完全退出运行的风险.对此,以交流系统发生最严重的三相短路故障为例,分析了MMC-UPFC串、并联侧MMC故障特性;在此基础上,借鉴风电场交流故障渡越的Chopper电...     

气隙结构对特高压并联电抗器铁芯振动的影响

以气隙个数和气隙位置对特高压并联电抗器铁芯振动的影响为主要研究对象,在分析特高压并联电抗器铁芯振动机制的基础上,指出了麦克斯韦力和磁致伸缩力的矢量和是影响铁芯振动强度的主要原因;系统分析了铁芯气隙可能存在的结构型式,搭建了具有不同气隙个数和气隙位置的特高压并联电抗器铁芯的真型仿真模型,并采用多物理场有限元仿真计算的方法,得到了气隙结构对特高压并联电抗器铁芯振动的影响规律。研究结果表明,在研究范围内(气隙个数为15~25),特高压并联电抗器铁芯气隙个数越少则振动强度越弱;气隙位置越靠近底轭则振动越强,越靠近铁芯柱3/4高度中心则振动越弱。在此基础上提出一种特高压并联电抗器铁芯减振设计方案,与现有铁芯设计方案相比该方案能够使铁芯振动位移均方根减小18.925%。     

LARGE AREA PIEZOELECTRIC ACTUATORS USING METAL FOIL SUBSTRATES WITH Pb(Zrx,Ti1 - x)O3 THIN FILMS

ABSTRACT

We report on the deposition of Pb(Zr_x,Ti_{1 - x})O₃ (PZT) thin films by chemical solution deposition (CSD) on stainless steel foils. The electrical characterization proves good ferroelectric properties with a remnant polarization of 38 μ C/cm². Since PZT is also piezoelectric the 35 μ m and 50 μ m thick metal foils are used to make piezoelectric actuated cantilever beams of several millimeter lengths. Actuated with 10–30 V a displacement up to 32 μ m was measured in quasi-static mode. In resonance mode the displacement increases several times at the same driving voltage.     

LAGRANGE MULTIPLIERS FOR THE INTERMEDIATE METALLIC REGIONS IN THE COMPUTATION OF THE POTENTIAL DISTRIBUTION OF INSULATOR CHAINS BY FEM

ABSTRACT

It is very important to predict the behaviour of the high voltage insulators at the operating conditions from the point of improving of the design and practical selection of the insulator type. Therefore, it is necessary to compute the potential and electric field distributions and to determine the critical regions forced much more by the electric field. In case the insulator surface is clean or the pollution film at the surface is dry, a little capacitive current flows and the solution of the problem results in a capacitive potential distribution.

In the numerical computational methods of potential distribution of insulator chains, it requires to insert into the resulting equation system as boundary conditions of the intermediate metallic zones that connect two units that have the same potential at every point. In this work, the potential distribution of clean insulator chains have been computed using the Finite Element Method (FEM). The metallic zones between the units have been taken into account as equipotential surfaces by Lagrange Multipliers. The computed results were compared with experimental results obtained by using the Conducting Paper Method and good agreement was observed.