Universal Access in the Information Society: Methods, Tools, and Interaction Technologies

Accessibility and high quality of interaction with products, applications, and services by anyone, anywhere, and at any time are fundamental requirements for universal access in the emerging Information Society. This paper discusses these requirements, and their relation to the concept of automated adaptation of user interfaces. An example application is presented, showing how adaptation can be used to accommodate the requirements of different user categories and contexts of use. This application is then used as a vehicle for discussing a new engineering paradigm appropriate for the development of adaptation-based user interfaces. Finally, the paper investigates issues concerning the interaction technologies required for universal access. Published online: 23 May 2001     

空气源热泵热水系统选型与热水需求适配问题研究

空气源热泵热水系统在工程实践中的应用越来越广泛,而要提升系统的热效率,系统选型需与热水需求有效适配.从两个视角入手,首先根据某地水温与气温的变化情况,采用多项式拟合得热泵产水量曲面,随后系统地分析了某医院1年的实际热水用水实测数据,并按以春分月、年平均、秋分月3种特定工况选型比较了空气源热泵产水量与热水用水量的匹配程度...     

具有非线性突触联接和适应性的人工神经元电路模型

基于匹配神经细胞突触、胞体和轴突的电神经生理特性,本文提出了一种接近真实神经细胞输入-输出关系和强度-时间曲线的,且具有非线性突触联接和适应性的非线性压控电阻电路模型,并分析了它的一些基本特性。结果表明,该模型比现存的神经网络更接近真实神经计算原理。由这一模型组成的胜者为王(WTAWinner-Takes-All)网络能够比模拟网络更有效地检测出最大输出,并引入了强度竞争和时间竞争两个新概念。     

基于概率推理的Ad-hoc网络路径选择算法

针对Ad-hoc网络在路径选择上主要选择最短路径所出现的问题,从复杂适应系统理论的角度出发,将基于概率推理的路径选择算法加入到AODV(Ad hoc on-demand distance-vector)路由协议中,通过对节点的适应度进行概率推理来选择路径,有效地解决了Ad-hoc网络的拥塞和负载分配问题,改善了网络性能。采用面向对象的建模技术在OMNET++软件平台上进行仿真,结果证明该方法降低了延迟时间,提高了网络QoS,为Ad-hoc网络路由协议的发展提供了一个新思路。     

MDM光波导激发高阶SPP模的传输特性

研究了金属-介质-金属(MDM)型表面等离子体激元(SPP)光波导的电磁特性。理论计算结果表明,对于633nm的TM偏振入射光,当介质膜层厚度小于85nm时,波导中只能激发产生一阶SPP模(基模),其余高阶模全部截止。随着介质膜厚度增加,高阶SPP模逐渐被激发产生。当介质膜层厚度较小时,SPP模的有效折射率的实部随阶数的增加而减小,而虚部则随阶数的增加而增加,SPP基模具有最大传输距离。然而,当MDM波导中的介质层厚度超过0.555μm时,由于三阶SPP模的电磁场主要集中在离金属层相对较远的介质层中,其有效折射率的虚部具有最小值,具有最大的传输距离,而非基模。当入射光波长为633nm介质层厚度为0.9μm时,Ag/SiO2/Ag光波导中三阶SPP模的传输距离达到约150μm。     

Extraction and recovery of cadmium(Ⅱ) using phosphine-oxide,tris[(dibutylamino)methyl]-(7CI,8CI) from nitric acid solutions

In the present article, a new separation system was employed for the extraction of cadmium from nitric acid solutions for the first time. Phosphine oxide, tris[(dibutylamino)methyl]-(7CI,8CI),which contains nitrogen atoms and phosphorus atom in molecular, was used as extractant. The influence of the following parameters was investigated: the organic/aqueous phase ratio (O/A), pH, contact time, temperature, the concentration of extractant, cadmium (Ⅱ), sodium nitrate and sodium chloride. Results demonstrated that quantitative extraction of cadmium was feasible from 50 mg/L cadmium feed solution in a single stage at pH 3.0, 15 min and O/A phase ratio 1:5 with 20% extractant in cyclohexane diluent. The cadmium extraction isotherm under different cadmium ion concentrations was established. The loaded cadmium could be stripped by 4 mol/L ammonium chloride aqueous solutions. A contrast study was carried out, and the results indicated that phosphine oxide, tris[(dibutylamino)methyl] –(7CI,8CI), could take the place of commercial organo-phosphorous extractants in the process of cadmium(II) extractions for its effectivity, stability and low price.     

自适应边缘检测方法的研究

图像的边缘是图像最基本也是最重要的特征之一。边缘检测一直是计算机视觉和图像处理领域的经典研究课题之一,在精确制导武器中有着广泛的运用。针对经典边缘检测方法在阈值选取中存在的问题,在分析几种二值化阈值选取方法的基础上,提出了自适应的边缘测检方法。基于C++Builder语言,研究了该方法的设计并得到了实现。通过实验验证,说明了该文方法的实用性和有效性。     

Incidence and Enumeration of Vibrio parahaemolyticus in Shellfish from Two Retail Sources and the Genetic Diversity of Isolates as Determined by RAPD-PCR Analysis

A total of 83 shellfish samples from two local retail sources (A and B) yielded 38 samples positive for the presence of Vibrio parahaemolyticus based on 3 tube MPN enrichments and isolation from thiosulfate-citrate-bile salts-sucrose agar (TCBS) and biochemical tests. The 38 positive samples yielded 133 biochemically presumptive isolates of V. parahaemolyticus. Among these 133 presumptive isolates, 104 were confirmed by the polymerase chain reaction (PCR), which yielded more reliable identification results than the biochemical tests. The 38 biochemically presumptive samples yielded 29 samples that were confirmed by PCR to be positive for the presence of V. parahaemolyticus. RAPD analysis with three random primers was performed to examine the genetic diversity of 64 strains among the PCR confirmed V. parahaemolyticus isolates from both retail sources. 52 of 56 composite RAPD types consisted of single strains, indicating that most of the V. parahaemolyticus isolates were genetically quite heterogeneous. No strains representing the same RAPD type occurred in both retail outlets, implying that contamination of the shellfish by V. parahaemolyticus from the 2 retail sources was from different environmental locals and shellfish harvesting areas. Eight genomic clusters were generated at the 25% similarity level in a dendrogram based on RAPD profiles. With few exception, isolates with close genetic relationships grouping into an individual cluster tended to be derived from the same retail source.     

城市中心老旧学校的改造与更新——成都树德中学改造小记

建筑改造的过程不仅仅是狭义的改变建筑外观的过程,而是对现状,包括功能、交通、立面、景观、材质、结构等内容进行评估之后,做出改造的判断及决策的过程。因此,在改造工程中,强调的是完善教学功能、体现历史文脉、形象、空间、景观一体化打造,以形成统一的、全新的、完整的校园空间。     

Oxidation of Fe–Si alloys in CO2–H2O atmospheres

Abstract

Iron and model alloys containing 1, 2, and 3wt% Si were reacted with dry and wet CO₂ gases at 800°C. All oxidised in dry CO₂ according to approximately linear kinetics. Additions of H₂O accelerated the reaction until steady-state parabolic kinetics were achieved. However, the effect of H₂O was small in the steady-state reaction stage of Fe – 3Si. Alloy reaction products were a duplex scale consisting of an outer FeO+Fe₃O₄ layer and an inner FeO+Fe₂SiO₄ layer, plus an internal oxidation zone, in all gases. In Fe – 1Si, amorphous SiO₂ precipitates in the internal oxidation zone grew with rod-like morphologies in all gases. However, internal amorphous SiO₂ precipitates grown in Fe – 2Si and Fe – 3Si formed network patterns. Internal penetration rates were initially rapid in Fe – 1Si, but slowed considerably at longer times. In Fe – 3Si, the internal oxidation zone grew wider in the first 20 h of reaction, and then remained constant in dry gas. In the wet gases this zone subsequently diminished, and disappeared after 50 h reaction.