Migration of soluble cadmium species in nickel-cadmium cells

It has been shown that migration of cadmium species, in the separator region of the nickel-cadmium cell, is most likely to occur via a diffusion contro     

增强现实光照方向估计方法评述与展望

光照一致性是增强现实中实现虚实融合的重要方面,实时地估计出户外场景中的光照方向,对实现户外场景光照一致性和增强真实感具有重要意义.针对光照方向估计问题,首先归纳了户外场景光照方向估计的特点,把现有的光照方向估计方法分为借助光测球等特殊标定物的估算方法、立体视觉法和人工智能法3类方法.然后总结了各类方法的基本原理和有代表性的研究工作,并且比较了各类方法的优缺点和适用范围.最后,根据实际应用中存在的问题和挑战,展望了户外增强现实系统光照方向估计的研究方向.     

单级倒立摆的PID控制研究

对单级倒立摆系统的平衡控制问题进行了研究，分别采用PD，PI和PID三种方案实现了单级倒立摆系统的平衡控制。首先，建立系统的数学模型，然后通过仿真实验设计并整定各方案的控制器参数，将所设计的控制器分别在实际的物理设备上进行实时控制实验，都成功地实现了倒立摆的平衡控制。实际控制结果验证了各方案的正确性和有效性。     

基于聚度的PSO参数分析

对PSO方法中粒子运行规律给出较为完整的分析,考察随机性对粒子运动过程的影响,提出聚度的概念,并 通过粒子的聚度考察粒子在实际运行条件下的分布情况,给出更加具体的参数设置区间,提出一种粒子在运动过程中 的速度补偿策略,对于一些参数设置可以通过该策略提高搜索性能,该策略对实际应用中选择和调整PSO算法参数 有较强的指导意义。     

Halftoning colour volume datasets based on subdivision

The algorithm for halftoning 2D gray scale images based on subdivision was extended to the processing of colour volume datasets. Two main improvements were made. The first is adding a procedure to deal with cases with large errors so as to reduce the total quantizing error. The second is randomizing the directions in which errors are propagated, assuring the even distribution of the halftoned binary voxels. In addition, a method used to process large volume datasets was also proposed. The new algorithm is simple in principle, but produces good halftoning results, especially in the boundary regions. It is especially applicable in the data preparation for the rapid forming of coloured models and heterogeneous objects.     

Light Scattering and Visibility Condition of Spatial Objects

Considering background radiation of different wave band at different typical time by using Modtran soft, the characteristic of light scattering and the visibility condition of spatial object are discussed. Using bi-directional reflectance distribution function, combining geometry modeling with orbit theory, we numerical calculate light scattering radiation of spatial objects and compare it with the background radiation. The best observation time and station can be obtained by analyzing the conditions of visibility.     

Improvement of microstructure property of low dielectric constant nanoporous SiOF thin films prepared by sol–gel method

Using hydrofluoric acid (HF) as acid catalyst, F doped nanoporous low-k SiO₂ thin films were prepared through sol–gel method. Compared with the hydrochloric acid (HCl) catalyzed film, the films showed better micro-structural and dielectric properties. The improvements were investigated by high-resolution scanning electron microscopy (HR-SEM), Fourier transform infrared spectroscopy (FTIR), and capacitance–voltage (C–V) and current–voltage (I–V) techniques. The results of N₂ adsorption/desorption further confirmed the HR-SEM morphologies and indicated that the suited introduction of HF increased the porosity and decreased the pore size distribution (about 10 nm). The incorporation of HF effectively adjusts the microstructures and the chemical bonds, and thus significantly improves the dielectric properties of the films; the dielectric constant was reduced to 1.5.     

Preparation of Monodisperse Nanoparticle of Layered Double Hydroxides and Polyoxyethylene Sulfate

1Introduction Layereddoublehydroxides(LDHs)havereceiveda considerableattentionduetotheirpropertiesandapplica tionasanionadsorbents,ionicconductors,catalysts,cat alystsupports,medicinestabilizers,nanocompositepre cursorandDNAreservoirs[13].Thesenanocomposi…     

Determination of melamine in milk powder,milk and fish feed by capillary electrophoresis: a good alternative to HPLC

BACKGROUND: Since September 2008, an increased incidence of kidney stones and renal failure in infants, associated with the ingestion of infant formula contaminated with melamine has been reported in China. Furthermore, melamine was not only found in many protein‐based food commodities, but also in the feeds for cattle and poultry. So it is necessary to develop a suitable method to determine melamine. RESULTS: A capillary zone electrophoresis (CZE) method for analysis of melamine was developed by use of running electrolyte containing 35 mmol L^?1 sodium dihydrogen phosphate at pH 3.5, with UV detection at 210 nm. Regression equation revealed linear relationships (r = 0.9999) between the peak‐area and the content of melamine from 0.8 to 80 µg mL^?1. The detection limit was 0.08 µg mL^?1. The method was successfully applied to the determination of melamine in milk powder, milk and fish feed, with the recoveries from 94.5% to 103.7%. CONCLUSION: The performance of the CZE method evaluated in terms of precision, limits of detection, accuracy and quantification were comparable and in good agreement with those obtained by the HPLC method, with the advantage of shorter analysis time and lower cost. Copyright © 2010 Society of Chemical Industry