英国《化学习题精选》(一)

《化学习题精选》是英国中学化学教师为学生提供复习和提高作业质量而编的。它的特点有:1.围绕题目编成一系列短小的问题。这些问题系按照英国现用的教材结构编写的;由浅入深,由易到难,逐步引导学生的学习兴趣;可在课内外用作讨论或练习之用。2.作者将各小题划分为三种类型:(1)知识性(以K表示),理解性(以C表示)及综合性(以H表示)。每小题都注明评分标准,用以了解学生的知识水平和分析问题、解决问题的能力。本书共有一百题,我们根据我国中学化学教学大纲的内容选译部分习题,供教师们参考、选用。选译习题中也略有超我国教材水平的,可作因材施教之用。习题的后面,附有用数字回答问题的答案。     

人类活动历史新起源(英文)

Archaeologists announce discovery of tools and spear points in South Africa that may be 70, 000 years old.     

学习领域和教学组织与安排

目前,教育界人士对职业学校的专业课程各持己见。有人认为职业技术培训过于理论化岸生无法在课堂上学到足够的应用性知识。所以,提出一个以     

Joint rate control and scheduling for wireless uplink video streaming

INTRODUCTION Video streaming is becoming one of the major driving forces of next generation wireless networks. For the currently deployed cellular networks, the practical data rates are not enough to support full rate, high quality video applications. As a result, many research efforts have been devoted to adapting video content to reconcile the conflict between the high demand of video quality and the limited wireless communication resources among users. A large body of literature utiliz…     

Psychosocial correlates of child abuse potential in multiply disadvantaged adolescent mothers

OBJECTIVE: This study had two aims: First to examine psychosocial correlates of child maltreatment risk, and second to assess the validity of the CAP Inventory (Milner, 1986) with multiply disadvantaged teenage mothers. METHOD: Participants were 75 adolescent mothers who were wards of the Illinois child protection system. Mothers (aged 14-18) and infants participated in home-based psychosocial assessment of personal and parenting functioning. Group comparisons examined differences for mothers with elevated versus normal versus invalid CAP scores due to faking good. RESULTS: Findings indicated that abuse risk groups differed on emotional distress, social support satisfaction, reading achievement, and years of education, but not on parenting beliefs or quality of child stimulation. Differences favored the normal over the elevated risk group in all significant comparisons, whereas mothers with elevated faking good differed from normals only in lower reading achievement. Multiple regression analysis highlighted emotional distress, support dissatisfaction, and low achievement as significant predictors of greater abuse risk. CONCLUSIONS: Despite sharing multiple disadvantages, adolescent wards are a heterogeneous group who show different levels of psychosocial functioning corresponding to levels of child maltreatment risk. The findings provide support for the concurrent validity and clinical applicability of the CAP Inventory with disadvantaged teenage mothers.     

Instructing adolescents with learning disabilities: converting a meta-analysis to practice

A previous meta-analysis indicated that eight instructional factors--Questioning, Sequencing and Segmentation, Skill Modeling, Organization and Explicit Practice, Small-Group Setting, Indirect Teacher Activities (e.g., homework), Technology, and Scaffolding-captured the majority of successful intervention programs for adolescents with learning disabilities (LD). Most important was the Organization/Explicit factor, which contributed significant variance (16%) to effect size. This factor included two important instructional components: advance organization and explicit practice. In this article, we convert these findings into practical guidelines to direct instructional practice.     

北太平洋巨型章鱼

北太平洋巨型章鱼是170余种巨型章鱼中的一种。人们曾经误把它们看成为海怪,实际上,它们性格平和,并不像古老传说描述的那样会攻击船只。     

Bringing text display digital radio to consumers with hearing loss

Radio is migrating to digital transmission, expanding its offerings to include captioning for individuals with hearing loss. Text display radio requires a large amount of word throughput with minimal screen display area, making good user interface design crucial to its success. In two experiments, we presented hearing, hard-of-hearing, and deaf consumers with National Public Radio stories converted to text and examined their preferences for and reactions to midsized and small radio text displays. We focused on physical display attributes such as text color, font style, line length, and scrolling type as well as emergency alert messages and emergency prompts for drivers, announcer identification schemes, and synchronization of audio and text. Results suggest that midsized, Global Positioning System (GPS)-style displays were well liked, synchronization of audio and text was important to comprehension and retrieval of story details, identification of announcers was served best with a combination of name change in parenthesis and color change, and a mixture of color and flashing symbols was preferred for emergency alerting.     

以90后视角写青春之作

我经常收到一些读者投稿,作文前面往往附着自我简介之类的资料,这些文字往往很有灵气,就是家常话也给人一种很亲切的感觉。比如,有个同学爆料她的家庭,说爸爸生意失败,一家人过得很苦,后来爸爸振作精神去跑运输,又出了车祸。妹妹不太听话,吃