增容剂对尼龙6／乙烯^=醋酸乙烯酯共聚物共混合金的亚微形态与力…

采用两种含有羟基官能团的共聚物作为增容剂，通过反应挤出法制备了尼龙６／乙烯－醋酸乙烯酯共聚物（ＥＶＡ）共混合金；并对合金的力学性能和亚微形态进行了研究，结果表明，通过挤出过程中增容剂的羧基宫能团与尼龙６反应，可提高尼龙６与ＥＶＡ的界面粘结性，从而使合金获得较高的缺口冲击强度，同时合金的断裂伸长率也显著提高，ＳＥＭ研究显示，ＥＶＡ与尼龙６的相容性较差，基体中ＥＶＡ粒子直径约为１．５－２．０ｕｍ；而添     

Integrating planning and learning: the PRODIGY architecture

Abstract

Planning is a complex reasoning task that is well suited for the study of improving performance and knowledge by learning, i.e. by accumulation and interpretation of planning experience. PRODIGY is an architecture that integrates planning with multiple learning mechanisms. Learning occurs at the planner's decision points and integration in PRODIGY is achieved via mutually interpretable knowledge structures. This article describes the PRODIGY planner, briefly reports on several learning modules developed earlier along the project, and presents in more detail two recently explored methods to learn to generate plans of better quality. We introduce the techniques, illustrate them with comprehensive examples, and show preliminary empirical results. The article also includes a retrospective discussion of the characteristics of the overall PRODIGY architecture and discusses their evolution within the goal of the project of building a large and robust integrated planning and learning system.     

APPLICATION OF MULTIVARIATE STATISTICAL ANALYSES TO THE STUDY OF FACTORS AFFECTING WHITE WINE VOLATILE COMPOSITION

ABSTRACT

The influence of different storage conditions on the volatile composition of young white wine was evaluated during 1 year of storage. The wine was bottled and stored under different conditions of temperature, position and illumination. During storage, a significant increase in total content esters (mainly due to the increase in ethyl butyrate, ethyl acetate and diethyl succinate) and total content acids was detected. Also total content alcohols and carbonyl compounds decreased during storage. Storage time, temperature and illumination have a significant effect on esters content, whereas carbonyl compounds are affected by temperature, and alcohols content is affected by illumination. Stepwise linear discriminant analysis was applied to the experimental data. The results showed that the samples were well classified as a function of storage temperature. On the other hand, a certain trend was observed when the wine samples were classified according to storage time. The samples corresponding to two and four months of storage were well differentiated from the rest.

PRACTICAL APPLICATIONS

From a sensory point of view, the aroma influences greatly the quality of wines. The loss of aromatic characteristics in young white wine, as well as browning, take place over a variable period of time which ranges from one month to several years, depending on wine type and storage conditions. Assessment of possible factors affecting the useful lifespan of young white wine is of great interest for the wine making industry. Knowing the chemical composition of wine, specifically aromas, and its evolution relating to different storage and preservation conditions is an important tool in quality control.     

用位误差率测试仪作为解决问题的工具

具有误差位置分析的位误差率测试仪已经长期应用于研发环境,以改善和评价数据存储和通讯领域中各种各样的系统和部件的性能。随着对位误差率是数据完整性中最明确的测量指标的日益认可,这些设备在通讯系统和部件的生产测试环境中得到了更广泛的应用。 一种用于评测高速多路复用器和信号分离器的独立的并联BER测试仪使这种倾向得到了加强,而且经常可     

采用LVDS实现成功通信的秘诀

低电压差分信令(LVDS)器件目前拥有多种版本可供选择.通常在同一系统中会共存不同版本的器件,这就造成了互操作性问题.在实际可用的版本中,设计人员可选择LVDS、基于总线的LVDS以及M-LVDS(多点LVDS)等不同器件版本.但这些器件是否可以在同一系统中协同工作呢?当设计人员在一个系统中混合采用不同技术时,应当解决哪些问题呢?结合采用相似却又不同的器件时,会有哪些限制呢?     

The Evolution of Curricular Change Models within the Foundation Coalition

This paper examines one aspect of the curricular change process undertaken by the Foundation Coalition (FC); specifically, how understanding about curricular change held by the FC leaders evolved as they moved through the process of establishing a new curriculum at their institutions. The initial change model was similar to that used for product development and emphasized the role of a pilot program. However, as the curriculum moved beyond the pilot stage to adoption and full‐scale implementation, and then into the final stage where sustaining the new curriculum was the focus, the change model became more complex. Those complexities reflect a parallel evolution in their understanding of what constitutes a curriculum, from their initial conceptualization of it as a product to be carefully designed towards an understanding of it as a dynamic entity whose growth must be sustained.