考虑出行方向的广州出租车时空可达性研究

出行方向是可达性研究中的一个关键要素, 因此, 提出一种考虑出行方向的出租车时空可达性分析方法。根据出租车经验路径分方向构建经验等级路网, 采用基于分层路网的Dijkstra算法计算得到各OD对之间的行程时间, 作为可达性评价指标, 并采用网格法和反距离加权插值法绘制得到广州市中心商业区等时线及其渲染图, 分方向、分时段对其时空可达性进行分析。结果证明了不同出行方向下, 特别是处于高峰时段, 可达性有较大的不同。     

多级孔沸石分子筛在芳烃烷基化反应中的研究进展

多级孔沸石分子筛不仅具有微孔沸石固有的高水热稳定性和强酸性,且兼具介孔以及大孔材料的传质优势,提高了表面活性位的有效利用率,在多相催化领域表现出良好的催化性能。本文详细阐述了近年来多级孔沸石在芳烃烷基化反应中的研究进展,讨论了多级孔沸石分子筛中介孔的存在对芳烃烷基化特别是其中包含有较大分子参与的烷基化催化反应的促进作用,从分子扩散和可接近性两方面解释了多级孔沸石对催化活性、选择性和稳定性的促进作用。同时指出制备具有高度有序结构的介孔沸石,并深入研究多级孔沸石的酸性,建立沸石酸性能、孔结构与催化性能之间的关联是未来多级孔沸石的研究方向。     

Tactile colour pictogram to improve artwork appreciation of people with visual impairments

A recent development in tactile technology enables an improvement in the appreciation of the visual arts for people with visual impairment (PVI). The tactile sense, in conjunction with, or a possibly as an alternative to, the auditory sense, would allow PVIs to approach artwork in a more self‐driven and engaging way that would be difficult to achieve with just an auditory stimulus. Tactile colour pictograms (TCPs), which are raised geometric patterns, are ideographic characters that are designed to enable PVIs to identify colours and interpret information by touch. In this article, three TCPs are introduced to code colours in the Munsell colour system. Each colour pattern consists of a basic cell size of 10 mm × 10 mm to represent the patterns consistently in terms of regular shape. Each TCP consists of basic geometric patterns that are combined to create primary, secondary, and tertiary colour pictograms of shapes indicating colour hue, intensity and lightness. Each TCP represents 29 colours including six hues; they were then further expanded to represent 53 colours. Two of them did not increase the cell size, the other increased the cell size 1.5 times for some colours, such as yellow‐orange, yellow, blue, and blue‐purple. Our proposed TCPs use a slightly larger cell size compared to most tactile patterns currently used to indicate colour, but code for more colours. With user experience and identification tests, conducted with 23 visually impaired adults, the effectiveness of the TCPs suggests that they were helpful for the participants.     

How virtual reality affects perceived learning effectiveness: a task–technology fit perspective

The application of virtual reality (VR) in improving users’ learning outcomes, especially in perceived learning effectiveness, is a new area. VR provides visualisation and interaction within a virtual world that closely resembles a real world, bringing an immersive study experience. It also has two special features: representational fidelity and immediacy of control. However, only when the technology fits the tasks that users are performing will it be adopted. In addition, technology itself cannot improve learning outcomes; certain learning behaviours, such as reflective thinking, should be prompted first so that learning outcomes can be improved. The research hypotheses derived from this model have empirically been validated using the responses to a survey among 180 users. These responses have been examined through SmartPLS 2.0. Surprisingly, task–technology fit does not moderate the relationship between VR and technology quality and the relationship between VR and technology accessibility. From this study, we can conclude that VR will influence reflective thinking and further indirectly improve perceived learning effectiveness.     

Silver Atomic Quantum Clusters of Three Atoms for Cancer Therapy: Targeting Chromatin Compaction to Increase the Therapeutic Index of Chemotherapy

Nanomaterials with very low atomicity deserve consideration as potential pharmacological agents owing to their very small size and to their properties that can be precisely tuned with minor modifications to their size. Here, it is shown that silver clusters of three atoms (Ag₃‐AQCs)—developed by an ad hoc method—augment chromatin accessibility. This effect only occurs during DNA replication. Coadministration of Ag₃‐AQCs increases the cytotoxic effect of DNA‐acting drugs on human lung carcinoma cells. In mice with orthotopic lung tumors, the coadministration of Ag₃‐AQCs increases the amount of cisplatin (CDDP) bound to the tumor DNA by fivefold without modifying CDDP levels in normal tissues. As a result, CDDP coadministered with Ag₃‐AQCs more strongly reduces the tumor burden. Evidence of the significance of targeting chromatin compaction to increase the therapeutic index of chemotherapy is now provided.     

基于Petri网的协同三维建模工作流模型研究*

通过分析大规模三维场景单机建模所面临的局限性问题,对三维场景协同建模理论进行了描述。结合workflow net的定义以及建立工作流模型的方法,采用基于Petri网扩展的、用于复杂工作流模型设计的建模方法建立协同三维建模的工作流模型,并通过Petri网相关理论分析得出所建模型具有可达性、有界性、活性,并且是安全可靠的,同时对系统中必须加以解决的并发问题进行了相关的探讨。     

The Web Designer's Guide to Color Research

ABSTRACT

Color plays an integral role in the success or failure of a Web site. Unfortunately, many Web designers misuse this vital element by making color design decisions based solely on personal opinions, rather than on scientific evidence. This evidence shows that color affects the viewers' experiences of the Web site in terms of how the viewers learn information, how they perceive the site's readability and download speed, and how satisfied they are with the Web site overall. This article (1) discusses the basic elements of color: hue, saturation, and luminance, (2) investigates the physiological, psychological, and cultural research on color perception, and (3) provides recommendations for Web designers based on this research.     

信息无障碍焦点问题及解决方案

从目前信息无障碍工作要解决的主要问题出发,分析了视觉障碍者、低收入人群、语言文化差异者在获取信息方面存在的困难,介绍国内外相关技术发展的情况,探讨解决问题的办法。     

Why people are reluctant to tempt fate.

The present research explored the belief that it is bad luck to "tempt fate." Studies 1 and 2 demonstrated that people do indeed have the intuition that actions that tempt fate increase the likelihood of negative outcomes. Studies 3-6 examined our claim that the intuition is due, in large part, to the combination of the automatic tendencies to attend to negative prospects and to use accessibility as a cue when judging likelihood. Study 3 demonstrated that negative outcomes are more accessible following actions that tempt fate than following actions that do not tempt fate. Studies 4 and 5 demonstrated that the heightened accessibility of negative outcomes mediates the elevated perceptions of likelihood. Finally, Study 6 examined the automatic nature of the underlying processes. The types of actions that are thought to tempt fate as well as the role of society and culture in shaping this magical belief are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)