流媒体技术与流媒体远程教育系统

一、流媒体技术概述随着宽带化成为建设信息高速网络架构的重点 ,许多城市的城域网从接入到核心各个部分都实现了宽带化 ,架构了以ＩＰ为基础的无阻塞数据承载平台。网络的宽带化不仅是为了使人们在宽阔的信息高速路上更顺畅地进行交流 ,使网络上的信息不再只是文本、图像或简单的声音文件 ,而且人们越来越希望宽带网络带来更直观更丰富的新一代的媒体信息表现。“流媒体 (ＳｔｒｅａｍｉｎｇＭｅｄｉａ)”技术便在这种要求下迅速发展起来。流媒体是指在互联网上以数据流的方式实时发布音、视频多媒体内容的媒体 ,而流媒体技术则是用于在Ｉ…     

科学教育概念辨析

科学技术的发展和社会的进步使得科学教育研究在世界范围内成为一个迅猛发展、日益重要的领域,很多学者也呼吁建立中国的科学教育学。但是,在当前科学教育研究的著述中对于科学教育的概念使用并不统一,所以,要建立一门规范的学科,首先要澄清科学教育这个最基本概念。一、关于科     

Development of an evaporation crystallizer for desalination of alkaline organic wastewater before incineration

A wastewater evaporation-desalination pretreatment method was introduced to remove the Na^＋ and K^＋ salts in volatile organic compounds （VOCs） wastewater before it was fed into the incinerator. VOCs in the wastewater were volatilized in the evaporation system and then the vapor was combusted in an incinerator. Simulated phenol wastewater containing sodium chloride was evaporated and concentrated and sodium chloride was crystallized in different parameters. The experimental results showed that the higher initial concentration of sodium chloride increases the ratio of volatilization of VOCs, which was due to the effect of “salting out” （a decrease in the solubility of the nonelectrolyte in the solution, or more rigorously, an increase in its activity coefficient, caused by the salt addition （Furter and Cook, 1967））. When evaporation speed was increased from 1.67 ml/min to 2.73 ml/min, the total removal coefficient of sodium chloride was about 99.88%-99.99%. This pretreatment procedure eliminates the slag phenomenon caused by Na^＋ and K^＋ salts during wastewater incineration, so the incinerator could operate continuously, and the wastewater evaporation could increase the heat value of wastewater, and the operation cost would be reduced.     

Stability of School Academic Performance Across Subject Areas

Recent studies on the stability of school academic performance across school subject areas show two weaknesses: a lack of research attention to elementary schools and a lack of adequate statistical adjustments for school characteristics. With data describing elementary students (N = 6,883 students in Grade 6 in 148 schools) from the New Brunswick School Climate Study (NBSCS), the current study examined correlates of academic performance across mathematics, science, reading, and writing among students and among schools, using a multivariate multilevel model with statistical adjustments for student characteristics and school context and climate characteristics. Results indicated that (a) students were differentially successful in different subject areas, (b) schools were differentially effective in different subject areas, and (c) the differential success was more obvious among students than among schools. Findings of this study call for a new type of school programs that aim to ensure that students progress equally in different subject areas and for stronger school policies that systematically coordinate classroom or department practices.     

Yimu San improves obstetric ability of pregnant mice by increasing serum oxytocin levels and connexin 43 expression in uterine smooth muscle

Prolonged farrowing remains one of the critical challenges in intensive pig farming. This study aims to explore the effects and mechanism of Yimu San (YMS), a Chinese veterinary medicine micro mist, on delivery ability with mouse models. Thirty-two pregnant mice were randomly divided into a control group and low-YMS, med-YMS, and high-YMS groups. The labor process time and stillbirth rate were recorded, the levels of serum oxytocin and prostaglandin E₂ (PGE₂) were measured with enzyme-linked immunosorbent assay (ELISA). Contractility measurements of the isolated uterus and the expression of connexin 43 (Cx43) in uterine smooth muscle were evaluated. The results showed that compared with the control group, the birth process time and stillbirth rate in the med-YMS and high-YMS groups were remarkably lower. The in vitro uterine contractions, levels of oxytocin, PGE₂, and Cx43 in the med-YMS and high-YMS groups were significantly higher than those in the control group. The differences of the above measurements between the low-YMS group and the control group were not obvious. It can be speculated that YMS could significantly promote labor in pregnant mice by enhancing the levels of oxytocin, Cx43, and PGE₂.     

教师职前教育存在的问题及对策研究

新课改对教师提出了新的能力要求,如丰厚的文化底蕴、良好的教育技术能力、心理学素养、教育研究能力以及合作能力。师范院校的毕业生因诸多能力缺失,难以适应新课改下的基础教育教学。究其原因,是由于师范学院课程体系偏重于以学科为中心,教学模式相对传统,教育实践机会较少。因此,师范教育需要构建新的课程体系,建立以学生为中心的教学模式,加大学生实践的力度和深度。     

高职生中厌学现象分析

分析了当前高职学生产生厌学的主客观原因，并结合实际情况，提出了改变和减少厌学现象的对策。     

并行信息检索及其相关技术

本文讨论了并行检索的要点、作用及相关体系结构。重点对MIMD体系结构和SIMD体系结构进行了探讨。     

建构主义理论对商务英语教学的启示

本文分析了建构主义学习理论和受其影响而形成的教学模式及其对商务英语教学的启示。文章认为,商务英语教学可以被看作一个市场行为;基于市场规律,本文试图探讨在建构主义学习理论指导下,如何在商务英语教学过程中采用新型的教学模式以实现供与求的有机结合。     

论《屈赋》中的几种动宾关系

:《屈赋》中除支配与被支配以外的几种动宾关系 ,即通常所说的使动、意动、处动、为动、对动、被动等 ,是古汉语中常见的一些语法现象 ,熟练地掌握和运用它 ,阅读古籍中遇到的许多疑难便能迎刃而解