单分散性硫族化合物半导体量子点的制备与表征

硫族半导体化合物大多具有直接能带结构,是良好的光电功能材料,其量子点具有典型的量子效应.介绍了单分散量子点的无机成核/有机包裹的合成方法,通过尺寸选择性沉淀可以得到单分散的量子点;TEM、XRDUV-Vis吸收谱对硫族量子点的表征.     

R-tree的查询代价模型分析及算法改进

提出一个R-tree的查询代价模型（Cost Model) ,在对该模型分析的基础上，对R-tree及其变种进行了改进，形成了CR^*-tree，分别对Cost Model和CR^*-tree做了实验，结果显示该Cost Model的平均误差为12．6％，而改进后的CR^*-tree查询性能比R^*-tree提高了4．25％。     

交互技术在手写公式编辑中的应用

遵循泛化计算理论，设计实现了一个联机手写公式编辑系统，以提高识别率和交互(效)率．该系统采用上下文感知技术来辅助切分、解决符号的二义性；采用备选择优、直接指定技术来修正字符的识别结果；采用局部放大解决笔画交叉时的分割问题；最后还给出一个补笔算法．实验表明，这些技术的应用使得数学公式的识别率和系统交互(效)率得到有效的提高，同时使该系统具有自然、隐式交互的特点。     

水中 ClO_2、Cl_2、ClO_2~- 及ClO_3~- 的连续碘量法测定

通过大量的试验确定了碘量法连续测定水中ＣｌＯ２、Ｃｌ２、ＣｌＯ－２和ＣｌＯ３－的适宜条件。该方法的准确度、精密度和灵敏度都较好。其方法的回收率：ＣｌＯ２为９６７８％；Ｃｌ２为９８１７％；ＣｌＯ－２为９７２８％；ＣｌＯ３－为１０３３１％。变异系数：ＣｌＯ２为１５２％；Ｃｌ２为２３７％；ＣｌＯ２－为２４３％；ＣｌＯ３－为３５６％。最低检出限：ＣｌＯ２为００５０ｍｇ／Ｌ；Ｃｌ２为００５０ｍｇ／Ｌ；ＣｌＯ２－为００５０ｍｇ／Ｌ；ＣｌＯ３－为０５００ｍｇ／Ｌ。     

基于Wirdows NT平台的USB设备驱动程序开发

介绍了National Semiconductor公司的USBN9603／USBN9604模块在Microsoft Windows NT平台上PC端USB设备驱动程序的开发过程以及该驱动程序的结构，并就与此相关的USB和WDM作了简单说明。     

Effect of Yttrium on Microstructures and Properties at Elevated Temperature of Mg-0.8Zr-0.35Zn Alloys

Asthelighteststructuralmetalmaterial ,themostobviousadvantagesofmagnesiumalloyaretheirhighspecificstrengthandspecificstiffness ,superdampingcapacityandmachinability ,excellentelectromagneticshieldingandnon toxicity .Theincreasingattentionhasbeenpaidonthepracticalapplicationofmagne siumalloysastheenergysavingandenvironmentpro tectionarebecomingtheworldfocus .However ,somedisadvantagessuchasignitableandcombustibledur ingmeltingandcastingandtheirrelativelypoorprop ertiesatelevatedtemperaturelimit…     

数显涡流电导仪的研制

本文利用ANSYS软件通过涡流检测线圈阻抗的数值计算,表明涡流检测传感器相对于被测导体的提离效应在阻抗平面图上是近似为直线的轨迹,提出利用相位变换的方法实现提离干扰信号的抑制,并在此原理基础上,设计了以ARM9微处理器为核心的、基于幅相鉴别抑制提离效应的涡流电导仪硬件电路,并给出了系统的软件层次框架.最后对标准试块进行测量,分析了测量结果和提离抑制效果,为研制智能化数显涡流电导仪提供了良好的基础.     

设备综合效能的应用框架体系研究

分别从设备综合效能的经典定义、相关工业标准、不足之处及其发展方向等几方面阐述了设备综合效能的相关理论.分析了设备综合效能和设备综合效率的异同点,指出设备综合效能在企业应用中的不足之处.建立了基于制造执行系统的设备综合效能应用框架体系,阐述了设备综合效能在设备维护系统和制造执行系统中的应用,并分析了设备综合效能的关键使能技术.     

Pulse Signal Recovery Method Based on Sparse Representation

Pulse signal recovery is to extract useful amplitude and time information from the pulse signal contaminated by noise.It is a great challenge to precisely recover the pulse signal in loud background noise.The conventional approaches,which are mostly based on the distribution of the pulse energy spectrum,do not well determine the locations and shapes of the pulses.In this paper,we propose a time domain method to reconstruct pulse signals.In the proposed approach,a sparse representation model is established to deal with the issue of the pulse signal recovery under noise conditions.The corresponding problem based on the sparse optimization model is solved by a matching pursuit algorithm.Simulations and experiments validate the effectiveness of the proposed approach on pulse signal recovery.     

Effects of coherency stress and vacancy sources/sinks on interdiffusion across coherent multilayer interfaces – Part II: Interface sharpening and intermixing rate

Vacancy-mediated interdiffusion in coherent Mo/V and Cu/Ni multilayers is simulated to evaluate the effects of coherency stress and vacancy sources/sinks on interface sharpening and the intermixing rate, using the phase field model developed in a previous paper for two limiting cases: ideal vacancy sources/sinks densely distributed or not present at all. Interface sharpening stems from a large diffusion coefficient asymmetry across the interface, which in turn originates from the large difference in vacancy formation and migration energies between the two constituent layers. Remarkable sharpening is found in Mo/V multilayers either with dense or without vacancy sources/sinks, but only in Cu/Ni with a high density of sources/sinks. Sharpening is suppressed by coherency stress in Cu/Ni regardless of the existence of vacancy sources/sinks, but only promoted in Mo/V with a high density of sources/sinks. The intermixing rate is suppressed in Mo/V by the introduction of a high density of vacancy sources/sinks that are parallel or perpendicular to the interfaces, or uniformly distributed in all orientations, but only promoted in Cu/Ni by the introduction of vacancy sources/sinks that are parallel to the interfaces. The intermixing rate is promoted in Mo/V by coherency stress regardless of the existence of vacancy sources/sinks, but promoted in Cu/Ni by coherency stress only when the vacancy sources/sinks are parallel to the interface or not present at all. The effects of that part of coherency stress induced by the mismatch in atomic volumes on interface sharpening and the intermixing rate are opposite to, but dominant over, those of the stress induced by lattice creation/annihilation in vacancy sources/sinks.