素GPI-环的幂零多项式

R是素 GPI-环 ,若多项式 f (x1,… ,xd)在 R上是幂零的 ,则或 f (x1,… ,xd)是 R的恒等式 ,或 R是有限域上的有限矩阵环 .     

地方求解

在中国经济转型的大背景下，地方政府已经预先调整了经济发展战略。而如何执行好中央要求的经济转型和宏观调控，同时又切实帮助企业解决转型带来的挑战和难题，是地方基层政府直面的新课题。     

中国现代珠算史料（1962年-1988年）

（四）中国珠协抓“珠心算”迈出三大步；从1982年起“珠心算”的普及与提高，开始被各省、自治区、直辖市珠协及基层群众所接受。不过苦于师资和教材缺乏，苦于组织能力和宣教能力困难，各省很快就拉开距离。     

Flexible Substrates with Polyimide Buffer Layers for Organic Light-Emitting Diodes

We report a new method to enhance the properties of the polyethyleneterephthalate (PET) substrates for flexible organic light-emitting diodes (OLEDs). By spin-coating a polyimide (PI) film between the PET and the indiumtin-oxide anode, the flexible substrate with a smooth surface, high transmission over the visible spectrum and     

Highly c-Oriented Nanocolumn Structure ZnO Films on Sapphire Substrates by Pulsed Laser Deposition

Highly c-oriented nanocolumn structure ZnO films were successfully deposited on sapphire (0001) substrates by pulsed laser deposition at a substrate temperature of 500℃ and 200mTorr oxygen pressure. X-ray diffraction, scanning electron microscopy, photoluminescence, and spectroscopic ellipsometry were used to characterize the     

云南省基层药品监管部门装备高科技检验车

不久前，国家食品药品监督管理局、中国药品生物制品检定所为云南省16个州市和两个县一次性装备了18辆药品快速检验车。此举将有效提高云南省各基层药品监管部门的监管效能，实现监管与检验的有机结合，建立以“掌握信息、快速筛选、靶向抽样、目标检验”为目的的基层药品监管体系。     

锂离子电池富锂锰基层状正极材料的稳定性

富锂锰基层状正极材料(xLi₂MnO₃·(1-x)LiMO₂,M=Ni,Co,Mn等)因其比容量高、成本低廉以及环境友好等优点,被认为是未来锂离子电池正极材料的最佳候选者之一。然而,该正极材料存在长循环中电压衰减过快、循环性能不佳和倍率性能较差等问题,严重阻碍了该材料的商业化应用。在这篇综述中,我们结合最新的研究进展从富锂锰基层状正极材料的稳定性出发,阐述了该材料的结构特性及电化学行为,并从体相掺杂和表面修饰两个方面,综述了提升富锂正极材料循环过程中稳定性的手段。最后,我们对该领域的发展趋势进行展望并认为体相掺杂和表面调控相结合的联合改性机制是未来该领域发展的方向。     

新型锌基层状双氢氧化物的原位合成及其机制

铝酸三钙(C3A)水化过程中可形成钙铝层状双氢氧化物(CaAl-layered double hydroxide,CaAl-LDH),利用该特性,将C3A投加至含锌溶液中,通过调节初始Zn2+浓度、反应时间及温度等条件原位即时合成了锌基层状双氢氧化物(ZnAl-LDH),并以XRD、FT-IR、SEM等手段对产物结构、形貌进行表征。结果表明,14mmol·L-1初始Zn2+浓度,2.5h反应时间和35℃反应温度为最佳的合成条件,此时产物ZnAl-LDH层间距为0.89nm,Zn2+负载量为13.73mmol·-1。本文结合合成过程中溶液组分的变化情况,初步探究了ZnAl-LDH原位即时形成机制,主要是C3A水化产物CaAl-LDH与Zn2+发生阳离子交换,以及自身溶解出的Al(OH)-4与Zn2+协同共沉淀。     

Influence of Annealing on Properties of ZnO Films Grown via Plasma－enhanced MOCVD

The structural and the optical properties of ZnO films with high quality grown via plasma-enhanced met-al-organic chemical vapour deposition(MOCVD) on C-plane sapphire substrate were studied. The crystallini-ty and the optical properties of the films are greatly improved having been annealed in oxygen plasma atmo-sphere. The structure, the band gap and the binding energy of O1s electrons, and the molar ratio of O to Zn were determined by X-ray diffraction (XRD), photoluminescence (PL) and X-ray photoelectron scan meth-ods. For both the annealed and the as-grown films, the exciton peak features were observed at room temper-ature. The band-edge photolof the annealed film is much stronger than that of the as-grown film, and the exciton peak relating to the deep level at 439 nm disappears. The molar ratio of O to Zn in the annealed film is 0. 91, while it is 0. 78 for the as-urown film.