Recipe for success — Lessons learnt from using xAPI within the Connected Learning Analytics toolkit

An ongoing challenge for Learning Analytics research has been the scalable derivation of user interaction data from multiple technologies. The complexities associated with this challenge are increasing as educators embrace an ever growing number of social and content related technologies. The Experience API (xAPI) alongside the development of user specific record stores has been touted as a means to address this challenge, but a number of subtle considerations must be made when using xAPI in Learning Analytics. This paper provides a general overview to the complexities and challenges of using xAPI in a general systemic analytics solution - called the Connected Learning Analytics (CLA) toolkit. The importance of design is emphasised, as is the notion of common vocabularies and xAPI Recipes. Early decisions about vocabularies and structural relationships between statements can serve to either facilitate or handicap later analytics solutions. The CLA toolkit case study provides us with a way of examining both the strengths and the weaknesses of the current xAPI specification, and we conclude with a proposal for how xAPI might be improved by using JSON-LD to formalise Recipes in a machine readable form.

Features of the geomagnetic field during the Holocene and Proterozoic

The geomagnetic field is one of the most fundamental geophysical properties of the Earth and has significantly contributed to our understanding of the internal structure of the Earth and its evolution. Paleomagnetic and paleointensity data have been crucial in shaping concepts like continental drift, magnetic reversals, as well as estimating the time when the Earth's core and associated geodynamo processes begun. The work of this dissertation is based on reliable Proterozoic and Holocene geomagnetic field intensity data obtained from rocks and archeological artifacts. New archeomagnetic field intensity results are presented for Finland, Estonia, Bulgaria, Italy and Switzerland. The data were obtained using sophisticated laboratory setups as well as various reliability checks and corrections. Inter-laboratory comparisons between three laboratories (Helsinki, Sofia and Liverpool) were performed in order to check the reliability of different paleointensity methods. The new intensity results fill up considerable gaps in the master curves for each region investigated. In order to interpret the paleointensity data of the Holocene period, a novel and user-friendly database (GEOMAGIA50) was constructed. This provided a new tool to independently test the reliability of various techniques and materials used in paleointensity determinations. The results show that archeological artifacts, if well fired, are the most suitable materials. Also lavas yield reliable paleointensity results, although they appear more scattered. This study also shows that reliable estimates are obtained using the Thellier methodology (and its modifications) with reliability checks. Global paleointensity curves during Paleozoic and Proterozoic have several time gaps with few or no intensity data. To define the global intensity behavior of the Earth's magnetic field during these times new rock types (meteorite impact rocks) were investigated. Two case histories are presented. The Ilyinets (Ukraine) impact melt rocks yielded a reliable paleointensity value at 440 Ma (Silurian), whereas the results from Jänisjärvi impact melts (Russian Karelia, ca. 700 Ma) might be biased towards high intensity values because of non-ideal magnetic mineralogy. The features of the geomagnetic field at 1.1 Ga are not well defined due to problems related to reversal asymmetries observed in Keweenawan data of the Lake Superior region. In this work new paleomagnetic, paleosecular variation and paleointensity results are reported from coeval diabases from Central Arizona and help understanding the asymmetry. The results confirm the earlier preliminary observations that the asymmetry is larger in Arizona than in Lake Superior area. Two of the mechanisms proposed to explain the asymmetry remain plausible: the plate motion and the non-dipole influence.

关于具有剪应力的普通湍流理论发展

本文叙述了周培源1945年发表具有剪应力的普通湍流理论以后,各种湍流模式理论的主要发展概况.

A esfinge clara em prosa moderna: a contribuição de Othon Moacyr Garcia aos estudos linguísticos, textuais e literários

Esta tese tem por objetivo avaliar a contribuição, a nosso ver pioneira, de Othon Moacyr Garcia para os estudos linguísticos, textuais e literários no Brasil. A primeira parte de nosso estudo se concentrará nas principais contribuições dadas pelo livro Comunicação em prosa moderna, cuja primeira edição data de 1967; a segunda parte estudará sua contribuição à crítica literária brasileira, por meio de seus ensaios estilísticos; a terceira parte consistirá num resumo de sua obra dispersa, e a quarta parte também será um resumo das cartas que recebeu e enviou em sua correspondência com escritores e estudiosos da língua e da literatura

菊小长管蚜的化学防治研究

菊小长管蚜Macrosiphorniella sanborni是昆明地区花卉主要害虫之一，该虫对菊花嫩叶，嫩梢，花柄及花勒为害率达65.0%，个别大棚高达100，损失产量25.0%。室内外用1.8爱福丁3000，2500，2000倍液敌敌畏1500，1000，800倍液进行毒杀试验，爱福丁室内的毒杀率达96.6%，敌敌畏达96.3%；田间爱福丁害83.39%，敌敌畏达80.20%。

碳化硅衬底氮化镓高电子迁移率晶体管及制作方法

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用1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮从硝酸介质中萃取钪

用1-苯基-3-甲基-4-苯甲酰基-5-吡唑啉酮(PMBP)做萃取剂研究了从HNO_3介质中痕量钪的溶剂萃取行为。发现在很低的酸度下,PMBP几乎可以定量地萃取痕量的钪。同时,也讨论了用PMBP从~(18)O离子辐照过的铀靶溶液中萃取分离钍时钪的沾污。

HIRFL 中控台束诊系统

本文介绍了HIRFL的中控台束诊系统的设计与实现。该系统从中控台的触摸板接收用户命令，然后经公共区送抵VAX通讯程序，再通过CAMAC的4096 * 24bit 静态存储器3821插件将命令送至一台286微机，由微机程序控制束诊设备读回数据，经相反的路径送抵VAX机束诊程序，再在中控台的显示器上显示出来。从显示出的数据可以了解束流品质，据此进行调束。该系统的所有程序都用C语言编写。通过公共区实现VAX机独立进程之间的通讯和通过3821实现VAX机和微机通讯是本工作鲜明的特点，也是本工作能否实现的关键之处。本工作除解决束诊系统难以挂接VAX机的问题外，其思想和方法还可应用于菘它分控站的分散与集中控制