丙酮缩二甲醇的合成及应用

介绍了丙酮缩二甲醇的合成方法及其主要用途,概要地报道了合成丙酮缩乙二醇及以此为原料合成丙酮缩二甲醇的新工艺。     

直接还原的技术进步及其在我国的发展

介绍直接还原的历史发展与现状，根据我国的实际情况阐述了直接还原技术在我国的发展前景，结合议题组过去的研究及最新的实验成果进行分析，并提出一些浅见。     

一种基于B/S的农业资源综合数据服务系统──通用农业资源数据服务系统开发设计

基于浏览器 /服务器 (B/S)结构的通用农业资源数据库系统 ,将农业统计中常用的 5 0 0多个技术指标分成三大类 ,17个小类 ,基本涵盖了农业生产和管理统计的主要领域 普通用户通过浏览器实现对数据库的组合查询或浏览 ,也可将数据文件下载 系统提供了 9种统计分析方法以及 5种预测方法 ,授权用户可进行数据文件上载 管理员通过浏览器可对数据库进行管理维护     

偏心因子数据的计算方法研究进展

从偏心因子(acentric factor)的定义出发，分析了ω数据的确定方法和获取数据的手段，评述了国内外ω计算方法的近期进展，包括对应态蒸气压关联方程法、对应态基团贡献法(CSGC)、图论法及拓扑法等，指出了各种方法的优缺点及最新的计算发展方向。     

区际协调机制的构建及政策思路

建立共同的决策机构和相对完善的决策机制是区域经济一体化最本质的体现。由于体制原因形成的“行政区经济”使我国区域经济发展和协作过程存在着诸多问题,构建行之有效的区际协调机制已成当务之急。     

An ERP study for the degrees of the difficulty in visual search

The present study mainly probed the relationships between ERP components and the degrees of difficulty in visual search. Three experimental and one controlled conditions were randomly selected. Results showed that the P1, N1, and P2 amplitudes and latencies had no significant differences among the three experimental and one controlled conditions, and the ERP waveforms of low perceptual load of visual search were different from that of high perceptual load. These results might indicate that the latencies and amplitudes of initial P1, N1 and P2 in high and low perceptual load conditions were almost the same. The ERP waveforms of parallel search were very different from that of serial search, and the ERP waveforms of serial search were very similar. The P3 amplitudes increased as the degrees of the difficulty in visual search decreased.     

Picturing the moon: Hevelius’s and Riccioli’s visual debate

This article investigates the maps of the moon produced in the mid-seventeenth century by Jesuit Giambattista Riccioli (1598-1671) and Johannes Hevelius (1611-1687), whose cartographic projects competed for widespread acceptance. Although Hevelius’s Selenographia (1647) was applauded for its many detailed, self-engraved pictures of the moon, his cartography and proposed nomenclature were supplanted by Riccioli’s as offered in Almagestum novum (1651), in spite of the latter’s simplistic pictures and promotion of geocentric cosmology. Exploring this paradox through pictorial analysis, three types of images common to both Selenographia and Almagestum novum are compared, employing an analytical tool developed by Svetlana Alpers in The art of describing (1983). A focus on this debate exposes the tensions evoked by new technologies of vision and competing cultures of visual epistemology in seventeenth-century astronomy. As both selenographers grappled with questions about the role of representation and what kinds of knowledge could be generated visually, the successes and failures of their competing projects present implications for the course of visual astronomy, as well as for our understanding of the use of ‘visual technologies’ in a period of controversy.     

道琼斯工业指数与纳斯达克指数的非线性协整分析

首先对道琼斯工业指数进行分整分析,长记忆的道指被分数维差分得到平稳时间序列;进而对纳指也进行分数维差分.由于两指数的分整阶数不同,故不存在线性协整关系,所以,文章着重讨论两指数的非线性协整关系.     

核磁共振成像用磁体的计算机辅助设计

核磁共振成像用的磁体要求在一定的磁场强度下保持大范围的均匀度。本文给出球形空芯磁体和环形空芯磁体的计算机辅助设计方法。     

DEA-based anti-HIV immunotherapy model

Acquiredimmunitydeficiencysyndrome(AIDS)isoneofthemostfataldiseasesthathasspreadacrossthewholeworldsinceitfirstoccurred.Itiscausedbythehumanimmunodeficiencyvirus(HIV)[1].Mostofthechemotherapiesareaimedatkillingorhaltingthepathogen,butanewtreatmentistoreduceviralpopulationandimprovetheimmuneresponse.Thistreatmentcanboosttheimmunesystemandservetohelpthebodyfightinfectiononitsown,soitiscalledantiHIVimmunotherapy[2,3].TheaimofthisworkistofindefficientstrategiesforsuchtreatmentsusingtheDataEnv…