脉冲光源原子吸收光谱仪信号数字处理软件的设计

通过实验室设计的脉冲光源钨丝原子吸收光谱仪,采集到一个分析信号和光源载波叠加的复合信号。为了从中提取原子吸收分析信号,首先对该复合信号进行数值微分,确定光源脉冲载波每个峰的坐标和相应的峰高,算出每个载波峰位相应的吸光度值,绘制吸收峰轮廓图;然后根据辛普森(Simpson)数值积分原理,求出吸收峰的面积,从而得到积分吸光度值。在微软公司的Visual Basic 6．0开发平台上,编写了实现上述功能的软件,以图形和数值的方式,同时输出每次测定结果。该软件系统和钨丝原子吸收光谱仪硬件系统相配合,对铜标准溶液的测试结果为:检出限为0．0133μg/ml,线性范围为0．10- 4．0μg／ml,对1．0μg／ml Cu(n=10)测定的精密度为RSD=4．05％。     

PROPERTIES OF W/Cu FGMS CONTAINING 1%TiC OR 1%La2O3 PREPARED USING GSUHP

W / Cu functionally gradient materials (FGMs) containing 1%La_2O_3 and 1%TiC were prepared using graded sintering under ultra-high pressure (GSUHP). The specimens have been found to exhibit low porosity (11.57% and 11.35%, respectively). Shearing strength of the specimens between layers is good. Moreover, the specimens have still demonstrated good performance in testing thermal-shock resistance. When power density of laser is 200MWm~(-2), the specimens have been tested for thermal-shock resistance (1000 times); the specimens that contained 1%La_2O_3 were not subjected to damage, whereas those that contained 1%TiC began to crack. Finally, effect of additives on thermal-shock resistance was also preliminarily discussed.     

垃圾腐殖土筛分工艺和筛分单元

主要介绍应用于垃圾筛分中腐殖土的分选环节,适用于垃圾含水率较高和较粘稠的垃圾腐殖土的筛分工艺和筛分单元的研究,介绍工艺中各个环节在腐殖土筛分中的作用,介绍腐殖土筛分中主要设备圆盘筛的设计,为适应含水率较高和粘稠的垃圾腐殖土的筛分做出的改进。     

混合梯度稀疏先验约束下的图像盲复原

图像盲复原旨在无参考的情况下准确估计模糊核并恢复潜在的清晰图像。现有研究成果表明,利用全变分模型对高阶图像梯度先验约束进行描述可以有效抑制复原图像中产生的阶梯效应。本文在实验观察和研究的基础上,提出了采用稀疏先验约束模型对盲复原过程进行正则化的方法,以获得更佳的图像复原效果。该方法利用图像高阶梯度的稀疏性,通过与低阶梯度相结合来构造混合梯度正则项。同时,在正则项中引入基于图像熵的自适应因子,来调节迭代优化过程中两类梯度先验的比例,以此获得更好的收敛性。仿真与实验证明,与现有图像盲复原先进方法相比,本文方法具有更优越的图像复原性能。     

基于模式空间处理的宽带测向算法

基于模式空间处理方法提出了一种不需要角度预估计的宽带空间谱估计算法,将总体最小二乘相干信号子空间算法(TLS-CSM)中的聚焦矩阵的构造方法和频率加权聚焦方法引入模式空间宽带空间谱估计算法中,结合了模式空间算法不需要角度预估计的优点和酉聚焦的无聚焦信噪比损失的特性,大大减小了聚焦过程中的信噪比损失,从而进一步提高了算法的性能。     

电网谐波对继电保护的影响与预防措施分析

先对电网谐波问题进行了分析,讨论了电网谐波对继电保护的影响以及对继电保护装置的影响,最后分析了目前预防谐波对继电保护影响的措施,并提出了可行性建议.     

北电ATM网络运维管理经验

北电ATM交换机的性能管理参数极为丰富，通过对其进行合理配置，可优化网络运行质量。文中介绍通过对北电ATM交换机上的Atmif和Aallces部件参数的合理配置，实现了SVC业务的优化路由选择，改善了仿真电路传输质量，并具体阐明了实际配置方法及注意事项。     

基于等效瞬时电感判别变压器励磁涌流的新算法

基于变压器铁心磁导率在励磁涌流与内部故障时变化情况的不同,应用瞬时励磁电感和等效瞬时电感的概念,可有效判别变压器励磁涌流.但是,现有的等效瞬时电感计算方法存在较大的误差,对准确判别变压器励磁涌流构成了威胁.为此,提出了改进型的等效瞬时电感计算方法,有效考虑了等效电阻的影响,极大地改善了计算精度.以此为基础,给出了2种判别励磁涌流方案,即时域法和频域法.通过动模实验,对改进型算法和现有的近似算法进行了对比研究.结果表明,应用改进型算法求取的等效瞬时电感更为准确,使时域法和频域法的判别精度得到了极大的改善,有力证实了文中所提出的新算法正确、可行、有效.     

An improved quantum-inspired evolutionary algorithm for coding resource optimization based network coding multicast scheme

This paper investigates how to minimize the required coding resources in network-coding-based multicast scenarios. An evolutionary algorithm (MEQEA) is proposed to address the above problem. Based on quantum-inspired evolutionary algorithm (QEA), MEQEA introduces multi-granularity evolution mechanism which allows different chromosomes, at each generation, to have different rotation angle step values for update. In virtue of this mechanism, MEQEA significantly improves its capability of exploration and exploitation, since its optimization performance is no longer overly dependant upon the single rotation angle step scheme shared by all chromosomes. MEQEA also presents an adaptive quantum mutation operation which is able to prevent local search efficiently. Simulations are carried out over a number of network topologies. The results show that MEQEA outperforms other heuristic algorithms and is characterized by high success ratio, fast convergence, and excellent global-search capability.     

Revealing and Eliminating the Light-Soaking Issue in Metal Oxide-Based Inverted Organic Solar Cells

Inverted organic solar cells (i-OSCs) provide an exciting opportunity for commercialization owing to their excellent device air stability. However, light soaking (LS) issue generally occurs in metal oxide based i-OSCs, causing drastically decreased performance. The underlying root of LS effect is not clearly clarified until now. Herein, it is demonstrated that the surface oxygen defects on metal oxide nanoparticles, such as chemisorbed superoxide (O²⁻) and hydroxide (OH) dangling bonds, are the main reasons for LS issue in i-OSCs. The O²⁻ layer induces band bending at the cathode interface and increases the work function (WF) of metal oxide, thus leading to inefficient charge transport. The dangling bonds serve as interfacial trap states and cause non-radiative recombination, thus leading to the reduced open circuit voltage (V_oc). With ultraviolet (UV) illumination, the surface oxygen defects are interacted with photogenerated carriers, thereby improving the photovoltaic performance. Additionally, UV pretreatment of metal oxide films is employed to eliminate the LS issue and the resulting device yields significantly improved fill factors from 50.20% to 73.50% in the pristine SnO₂ based i-OSCs. This study reveals the origin of LS effect in i-OSCs and proposes a suggested model for LS mechanism.