三元场对小白鼠SOD活性影响的研究

超氧化物歧化酶(SOD)广泛存在于各种生物体内,是迄今为止发现的唯一以氧自由基为底物的酶,SOD是生物体内一种重要的氧自由基清除剂,对生物起防护作用,具有抗衰老、抗肿瘤、抗免疫性疾病和辐射防护的作用,通过化学法测定SOD,以研究元极堂内三元场对小鼠SOD活性的影响,探讨防病治病延缓衰老作用的机理,测试结果表明:小白鼠肝、脑SOD活性均提高近1倍,证实元极堂内三元场具有防治疾病等作用。     

The influence of high-stakes testing on teacher self-efficacy and job-related stress

In the United States, teachers’ job-related stress and self-efficacy levels across all grades are influenced in some manner by the demands of high-stakes testing. This sequential mixed-methods study aimed at examining the dynamics among assigned subject matter, teacher job-related stress, and teacher self-efficacy in a large south-eastern Texas school district. Quantitative data were collected via the High Stakes Testing on Self-Efficacy and Teacher Stress Survey from a convenience sample of 145 teachers, while qualitative data were gathered during focus-group sessions at the elementary, middle and high school levels. Findings indicated that assigned subject matter did not influence teacher self-efficacy, but did influence teachers’ job-related stress. Additionally, a relationship was found to exist between teacher job-related stress and teacher self-efficacy. Teachers reported lack of time, modifications to curriculum, and testing of special education populations as contributions to their job-related stress, and school leadership and educational triage as impacting their teacher self-efficacy.     

《工程图学》课程现代教学模式的研究与实践

《工程图学》课程传统教学模式已无法适应时代的要求。在教学改革实践中,积极探索了一种以计算机绘图为主线,以多媒体技术和网络教学为手段,具有立体、互动、高效特征的的现代教学模式。加强相关教材改革,利用网络辅助教学和素材资源的建设是实施现代教学模式的有力保证。     

The Role of Mathematics Teachers' Content Knowledge in their Teaching: A Framework for Research applied to a Study of Student Teachers

The authors develop and explain a framework toguide research on the relationship betweenmathematics teachers' knowledge of content andtheir teaching. The framework istwo-dimensional. The dimensions are (a) theelements of teaching and (b) the processes ofteaching in which knowledge of content is ofconsequence. The interplay between the elementsof teaching and the processes of teaching isdiscussed theoretically, consideringconnections to existing literature about therole of teachers' subject matter knowledge.Three vignettes from the authors' work withpre-service secondary mathematics teachersinvestigate further the relationship betweencontent knowledge and effective mathematicsteaching. The vignettes also serve toillustrate the complexity of investigationsinto this relationship. Direction is offeredfor use of the framework in future research.     

The Role and Value of Technical Communicators: Technical Communicators and Subject Matter Experts Weigh In

This qualitative study compares how technical communicators (TCs) and subject matter experts (SMEs) characterize the role and value of the TC. Seven TCs and eight SMEs participated in an investigation of the similarities and differences between the perceptions of these two groups. Key findings are that SMEs perceive of TCs as investigators, educators, and relationship builders; TCs talk about themselves in terms of investigators, interpreters, and audience advocates; and TCs are often uncomfortable discussing their value.     

黄淮白山羊心脏冠状动脉形态特征研究

目的:观察黄淮白山羊心脏冠状动脉的形态学特征,为其研究提供基础资料.方法:选择成年健康黄淮白山羊10头,采用颈静脉放血方式处死,其中6只心脏取不同管径大小的冠状动脉,多聚甲醛溶液固定,经水洗、脱水、二甲苯透明,石蜡包埋以HE、Masson三色及Verhoeff VG染色等步骤,观察冠状动脉的基本组织结构特点;另4只心脏标本经左、右冠状动脉口分别加压注入丁腈苯乙烯(ABS)丙酮溶液,经凝固成型后于70%浓盐酸溶液中腐蚀,观察冠状动脉的分支与分布.结果:黄淮白山羊的心脏左、右冠状动脉均起自于主动脉窦,行走于肺动脉与左心耳之间的左冠状动脉较粗大.黄淮白山羊弹性冠状动脉中弹性纤维含量丰富,外膜层有散在分布的块状平滑肌;肌性冠状动脉内外弹性膜结构清晰,中膜层主要由发达的平滑肌构成,含少量弹性纤维;微冠状动脉由一层内皮细胞构成.结论:黄淮白山羊冠状动脉属于左优势型,可分为弹性冠状动脉、肌性冠状动脉和微动脉三种类型.     

美国数学教师学科知识研究的概述和启示

我们对美国近五十年有关教师学科知识及其应用的研究方式和发展途径进行了概述和评论,在职教师培训重视教学专题学习以提升教学内容知识,职前培训重视教学论和教学方法课的学习,以积累总的分析和理解教学内容知识的观念和方法,是对我国数学教师学科知识教育最有益的借鉴和启示。     

小粒稻和大粒稻分蘖的~(32)P、~(14)C和器官的干物质(英文)

小粒稻和大粒稻的生理研究,无疑对水稻育种和水稻栽培十分重要。本文采用小粒稻和大粒稻共6个品种:南泰8号、七桂早25,三黄占(小粒)、美果选、特青2号、双桂36(大粒)作为试验材料,于玻璃网室内盆栽,每盆4株,肥、水及其管理一致,播种后定期测量植株分蘖数、顶上4片的叶片、叶鞘、茎穗干物重,收割时进行常规考种。试验结果表明,~(32)P、~(14)C在小粒稻和大粒稻分蘖的分布(％)不同,大粒稻“美果选”比“特青 2号”和“双桂36”~(32)P在分蘖分布多,~(14)C在分蘖少,分蘖数也少,小粒稻“南泰8号”~(32)在分蘖分布(％)比“七桂早25”和“三黄占”多,分蘖数也多。小粒稻“南泰8号”和大粒稻“美果选”,生育后期植株干物质保留在叶片、叶鞘和茎秆节间比其余品种多,其余小粒稻和大粒稻叶片、叶鞘和茎秆干物重贡献给稻穗增重较多,“美果选”的分蘖干物重和植株地上部干物重,比其余大粒稻品种减轻。大粒稻,“美果选”和小粒稻“南泰8号”的充实粒数少,谷粒产量低。实验结果证实王永锐(1986)提出的高产水稻品种生育后期,确实存在有“两段式阶梯灌浆形式”,如大粒稻“特青2号”,“双桂36”,小粒稻“七桂早25”,“三黄占”,并认为这可作为水稻选育种和高产栽培的生理指标,以及作为水稻生理育种的指标。     

刺五加对家兔白细胞的影响

利用环磷酰胺诱导家兔白细胞数目减少，模拟病态系统，建立实验机制．观察刺五加糖类提取液使家兔白细胞数目减少后的再恢复效果．