UTILIZING CONTEXT HISTORY TO PROVIDE DYNAMIC ADAPTATIONS

In order to provide “intimate” and “dynamic” adaptations under Weiser's vision for ubiquitous computing environments, we propose the utilization of context history together with user modeling and machine learning techniques. Our approach supports proactive adaptations by inducing patterns of user behavior. In addition, we support the requirement for enabling the user to receive an explicit and understandable explanation when a proactive adaptation occurs in order to encourage a trust relationship between the user and the context-aware system. In this article, we describe an experiment to examine the feasibility of our approach for supporting proactive adaptations in the domain of an intelligent office environment. The initial results of our experiment are promising and demonstrate how our system could gradually learn the user's preferences for controling his office environment by making inductions from the context history. Based on these initial findings, we believe that context history has a concrete role to play in supporting proactive adaptation in a ubiquitous computing environment.     

Preparation of Al2TiO5 from alkoxides and the effects of additives on its properties

Al2TiO5 was prepared by the sol-gel method from alkoxides and its mechanical and thermal properties measured. The prepared Al2TiO5 powder was very fine and had a narrow particle-size distribution. The addition of mullite and Al2O3 to the prepared Al2TiO5 inhibited the grain growth during sintering, resulting in a decrease of microcracking and an increase of fracture strength. Al2TiO5/mullite composite exhibited a higher fracture strength than Al2TiO5/alumina composite. The thermal expansion coefficient of Al2TiO5 increased with the addition of mullite and alumina, and also increased with temperature up to 1000°C; however, it decreased in the temperature range between 1000 and 1200°C during heating, due to decomposition of Al2TiO5. The addition of mullite inhibited the decomposition of Al2TiO5, but the addition of Al2O3 accelerated it. Al2TiO5 prepared from metal alkoxides was also more stable than that prepared from the commercial alumina and titania powders. This revised version was published online in November 2006 with corrections to the Cover Date.     

Dielectrophoretic assembly of semiconducting single-walled carbon nanotube transistor

A novel burning technique for making a semiconducting single-walled carbon nanotubes (SWNTs) transistor assembled by the dielectrophoretic force was suggested. The fabrication process consisted of two steps. First, to align and attach a bundle of SWNTs between the source and drain, the alternating (AC) voltage was applied to the electrodes. When a bundle of SWNTs was connected between two electrodes, some of metallic nanotubes and semi-conducing nanotubes existed together. The second step is to burn the metallic SWNTS by applying the voltage between two electrodes. With increasing the voltage, more current flowed through the metallic SWNTs, thus, the metallic SWNTs burnt earlier than the semiconducting one. This technique enables to obtain only semi-conducting SWNTs connection in the transistor. Through the I-V characteristic graph, the moment of metallic SWNTs burning and the characteristic of semi-conducing nanotubes were verified.     

亚甲基兰在AC和TiO2/AC上的吸附及催化臭氧氧化

研究了活性炭(AC)和负载二氧化钛的活性炭(TiO2/AC)对亚甲基兰的吸附特性及单独臭氧氧化,AC催化臭氧氧化和TiO2/AC催化臭氧氧化处理水中亚甲基兰的效果.结果表明:AC、TiO2/AC吸附亚甲基兰均较好地符合一级动力学模型及Langmuir方程,AC对亚甲基兰的吸附性能优于TiO2/AC;催化臭氧氧化的脱色速率比单独臭氧氧化略高,且对亚甲基兰吸附性能好的AC作催化剂时脱色效率更高.催化臭氧氧化比单独臭氧氧化对亚甲基兰的矿化率有明显的提高,TiO2/AC的催化活性优于AC.在催化臭氧氧化过程中,伴随着亚甲基兰的分解生成一系列中间产物并逐渐完全氧化.     

微滤技术/紫外线辅助催化臭氧氧化组合工艺处理洗车废水中试研究

用微滤技术/紫外线(MF/UV)辅助催化臭氧氧化组合工艺进行洗车废水处理回用的中试研究,结果表明操作压力≤20 kPa时,膜通量长期稳定.膜滤对COD、TN、TP和SS的去除率分别达到69.74%、40.12%、37.81%和100.00%,但膜滤对阴离子表面活性剂(LAS)基本没有去除效果.UV辅助催化臭氧氧化对膜滤出水进一步降解,系统出水水质良好,符合生活杂用水水质标准(CJ/T48-1999).     

六方-BN对非晶前驱体制备不含添加剂的Si3N4/SiC复合材料相变的影响（英文）

Si3N4/SiC纳米复合材料由于具有优良的力学和热性能,广泛应用于涡轮发动机、热交换器和其他复杂情况中。然而,不添加添加剂很难制备出Si3N4/SiC复合材料。添加剂在烧结过程形成液相从而促进复合材料的致密化。然而,添加剂的存在降低了复合材料的高温力学性能。通常在不添加添加剂的情况下,采用电场辅助烧结,利用聚合物前体路线制备Si3N4/SiC复合材料。本研究中,在无添加剂、温度1700°C、真空50MPa条件下,热压烧结2h,利用非晶前体路线成功制备了六方-BN致密化的Si3N4/SiC复合材料。聚合物前驱体和BN的作用减少了的SiC含量。并对相变、致密化、微观组织和力学性能进行了讨论。     

Characteristic evaluation of Al_2O_3/CNTs hybrid materials for micro-electrical discharge machining

The characteristic evaluation of aluminum oxide (Al2O3)/carbon nanotubes (CNTs) hybrid composites for micro-electrical discharge machining (EDM) was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. Al2O3 composites with different CNT concentrations were synthesized. The electrical characteristic of Al2O3/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the cha...     

Effects of poly‐γ‐glutamic acid on the physicochemical characteristics of skim milk yoghurt

The physicochemical and sensory properties of skim milk yoghurts containing poly‐γ‐glutamic acid (PGA) at different levels (0.0025, 0.005 and 0.01%) were evaluated. Addition of PGA up to 0.01% to reconstituted skim milk (11%, w/v) did not affect the growth of lactic acid bacteria or the development of titratable acidity in yoghurt, whereas full‐fat control yoghurt had reduced acid production. No changes were found in viable cell counts of PGA yoghurts during storage (4 weeks at 4 °C). The addition of PGA (0.005%) significantly decreased syneresis in skim milk yoghurt and did not cause any undesirable effects in sensory acceptability.