多巴胺能药物对鲤鱼生长激素分泌活动的影响

研究多巴胺（Dopamine，DA）及其激动剂阿朴吗啡（Apomorphine，APO）、拮抗剂Domperidone（DOM）对不同性腺发育时期和不同年龄雌鲤生长激素（GH）分泌活动的影响．结果表明，鲤鱼基础GH分泌存在明显的季节性变化：性腺发育早期＜性肠成熟期＜性腺退化期．DA和APO刺激的GH分泌也存在明显的季节性变化：性腺发育早期＞性腺成熟期＞性腺退化期．DOM不影响性腺发有早期和性腺成熟期的GH分泌，但显著性降低性腺退化期的GH水平．6月龄鱼血清基础GH水平明显低于2～3龄和1龄鱼；不同年龄鱼对多巴胺能药物的反应性表现为：1龄色最强，2～3龄和6月龄鱼较弱．     

The Effects of Cooperative Mastery Learning Strategies on Mathematics Achievement

Abstract

This study investigated the effects of student-teams using mastery learning strategies (STML) on mathematics achievement of fifth-grade children (N = 134). The experiment used a 2 x 2 (Student Teams x Mastery Learning) factorial design. Results showed higher achievement gains for pupils exposed to STML than for those exposed through more traditional instruction. The data further indicated that learning in small groups promoted only computational skills whereas mastery learning strategies improved both computation and comprehension. In addition, the benefits of the methods for high-, medium-, and low-ability students were examined and discussed.     

Different Logo Learning Environments and Mastery:

No abstract available for this article.     

The Effects of Formative Evaluation and Remediation on Mastery of Intellectual Skills

Abstract

The purpose of this study was to test Gagne’s hypothesis that attention to prerequisites should be more effective than repeated practice of a final task when learning intellectual skills. Ninety eighth-grade general science students studied self-instructional materials on the construction and interpretation of graphs. After each of three lessons each subject took a diagnostic test covering the objectives of the instruction. Subjects in Group 1 received additional instruction on prerequisites as remediation. Subjects in Group 2 received additional practice items as remediation, and subjects in Group 3 received no remedial activity. Students receiving remedial instruction did significantly better than those receiving only main-line instruction. Students receiving additional instruction on prerequisites did significantly better than those receiving additional practice items as remediation.     

历代灞桥位置变迁及原因探析

灞桥是古代长安通向东方的必经之地,在我国古代交通史上占有重要的地位。本文探讨了历史时期灞桥的历次修建、使用情况,复原了不同时期灞桥的位置所在;认为都城位置、自然地理因素和人类活动造成了灞桥的频繁迁移。     

A Rubric for Self-Assessment of Essential Technology Conditions in Schools

This article describes the development of a Web-based instrument that is part of a strategic planning initiative in technology in K–12 schools in Nebraska. The instrument provides rubrics for self-assessment of essential conditions necessary for integrating and adopting of technology. Essential conditions were defined by an extended panel of educators from across the state. The rubric examines the areas of (a) technology administration and support, (b) technology capacity, (c) educator competencies and professional development, (d) learners and learning, and (e) accountability. Each area is assessed by four to seven items that are rated using explicitly described criteria. The Web-based system allows schools to complete this rubric as part of the needs assessment process and make comparisons on their profile from year to year and relative to a statewide composite profile. Based on data from 2005 and 2006, reliability scores (Cronbach's alpha) for subscales ranged from .68 to .82. Reliability for the entire scale was .92. Examination of data over the first two years of implementation showed significant year-to-year positive mean differences in subscale scores, indicating that the instrument was sensitive to changing conditions. Effect sizes were small but acceptable.     

不同年龄阶段幼儿发思维发展的特点及趋势

本研究采用个别施测的方法，对193名3-7岁幼儿进行了发散思维测验，得到了以下几点结论：(1)幼儿发散思维发展存在着十分显的年龄差异，呈现出随年龄的增长发散思维能力逐步提高的趋势。(2)幼儿发散思维发展的进程不是匀速推进的，5岁左右是幼儿发散思维发展转折期。(3)从总体来看，幼儿发散思维的发展无显的性别差异，但是随着年龄的增长，男孩在发散思维独特性上的优势逐渐显露出来。(4)幼儿发散思维的发展存在很大的个体差异。     

高产几丁质酶玫烟色棒束孢菌株筛选及发酵条件优化

通过测定几丁质酶活力的方法对来源于不同寄主和采集地的16株玫烟色棒束孢进行筛选,获得活性较高菌株RCEF3304,并对高活力菌株RCEF3304产几丁质酶的pH值、装液量、接种量和温度等发酵条件进行优化研究。结果表明高酶活菌株产酶最适条件:胶体几丁质2%,NaNO33%,Mg2+0.05%,培养基初始pH值6.0,接种量12%,100 mL装液量为10 mL,温度25℃和培养时间36 h;最适发酵工艺条件下,几丁质酶酶活OD值达到0.486,比优化前发酵水平提高了128%。     

Effects of Exhaust Gas Recirculation on the Homogeneous Charge Combustion Process of n-Heptane at Different Load Conditions

Effects of exhaust gas recirculation （ EGR） on homogeneous charge combustion of n-heptane was studied through simulation and experiment. Experiments were carried out in a single cylinder, four-stroke, air cooled engine and a single cylinder, two-stroke, water cooled engine. In the four-stroke engine, experiments of the effects of EGR were examined using heated N2 addition as a surrogate for external EGR and modifying engine to increase internal EGR. The ignition timing was sensitive to EGR due to thermal and chemical effects. EGR or extra air is a key factor in eliminating knock during mid-load conditions. For higher load operation the only way to avoid knock is to control reaction timing through the use of spark ignition. Experimental and modeling results from the twostroke engine show that auto-ignition can be avoided by increasing the engine speed. The twostroke engine experiments indicate that high levels of internal EGR can enable spark ignition at lean conditions. At higher load conditions, increasing the engine speed is an effective method to control transition from homogeneous charge compression ignition （ HCCI） operation to non-HCCI operation and successful spark ignition of a highly dilute mixture can avoid serious knock.     

唐太宗的自我认识

唐太宗是一位成功的皇帝,他的成功来自他对当时时局的正确分析,来自他对自己作为一个帝王与人民、与臣下关系的正确认识。他懂得怎样才能做好一个帝王,怎样正确认识自己取得的成就。他之所以能获得对自己的正确认识,给自己正确定位,是因为他善于吸取历史的经验教训,虚心听取不同意见,找出自己的不足,及时纠正错误。贞观时期因此成为中国历史上著名的治世。     

Mastery learning and students' attributions at the college level

This study was designed to determine whether the more favorable learning conditions provided by mastery learning procedures result in higher levels of achievement and more internal attributions on the part of college students. One hundred twenty-two undergraduate students enrolled in a general education course at a large state university participated in the study. Results showed that although students in mastery-taught sections did attain significantly higher levels of achievement no differences in attribution change were identified. Possible reasons for the lack of attribution change are discussed.An earlier version of this paper was presented at the annual meeting of the American Educational Research Association Montreal, Canada, 1983.     

复合矿物包膜尿素在土壤中的氮素释放研究

本研究主要从降低包膜肥料的成本出发,以复合改性矿物为包膜材料制成的包膜尿素作为研究对象。利用土壤培养实验,通过测定包膜内残留的养分含量,研究不同土壤水分、土壤质地、土壤温度等环境条件对包膜尿素在土壤中氮素释放速率的影响,希望能对复合改性矿物包膜肥料的制造、施用提供科学的依据。     

党在不同历史时期对社会主义与资本主义关系的认识和把握

社会主义建设初期，我党提出向外国学习一定要与中国实际相结合，党的十一届三中全会到党的十四大召开期间，我党客观地承认资本主义应有的历史地位，把资本主义的发展与社会主义自身的发展联系起来，党的十五大之后，认为社会主义与资本主义并存是一个长期阶段，但不会改变资本主义最终必然被社会主义所取代的命运。     

信息时代的大学——新加坡高等教育信息化的发展及启示

新加坡高等教育信息化包括基础设施信息化、教学信息化等，揭示其发展成功的原因，探寻对我国高校信息化发展的启示，具有重要意义。     

不同成熟度龙眼叶片组织显微结构的观察

采用石蜡切片法对龙眼不同成熟度叶片的显微结构进行了比较研究。结果表明嫩叶、成熟叶和老熟叶在上下表皮厚度、角质层、乳突状突起及栅栏组织、海绵组织和维管束的显微结构上存在明显差别。本文也讨论了不同成熟度叶片与光合作用和逆抗性的关系。     

The Effects of Classwide Self-Assessment on Preschool Children's Engagement in Transition,Free Play and Small Group Instruction

The effectiveness of using a group self-management procedure to increase the on-task behavior of four disruptive preschool boys was studied using a reversal design combined with a multiple baseline across settings design. Measures of child and teacher behavior were obtained through direct observation during free play, transition, and small group instruction activities. The classwide procedure, which included self-assessment by the students, matching the assessments with the teacher, and reinforcement based on a match between teacher and child ratings, was conducted by teachers in two classrooms located at a Head Start center in a large urban area. Results suggest that use of the procedure improved on-task behavior of the target students and decreased off-task and competing behavior. For the teachers, use of a group approach to self-management served the dual purpose of addressing individual student needs while promoting independent and responsible behavior for all members of the class.     

不同年龄段教师培训需求调查及培训策略研究

培训需求分析是增强培训针对性、确保按需施训的基本前提。四川省一项有22.56 万中 小学教师参与的调查发现,不同年龄段教师在培训内容、培训专家、培训方式方法等方面有共同的 需求,但也存在差异。总体上看,对专业能力的培训需求随着年龄的增长而下降,对专业理念和专业知识的需求随着年龄的增长而增长。影响不同年龄段教师培训需求的因素,一是教师专业成长的阶段特征,二是教学的实践特征和社会期望。     

The Effects of Classwide Self-Assessment on Preschool Children's Engagement in Transition, Free Play and Small Group Instruction

The effectiveness of using a group self-management procedure to increase the on-task behavior of four disruptive preschool boys was studied using a reversal design combined with a multiple baseline across settings design. Measures of child and teacher behavior were obtained through direct observation during free play, transition, and small group instruction activities. The classwide procedure, which included self-assessment by the students, matching the assessments with the teacher, and reinforcement based on a match between teacher and child ratings, was conducted by teachers in two classrooms located at a Head Start center in a large urban area. Results suggest that use of the procedure improved on-task behavior of the target students and decreased off-task and competing behavior. For the teachers, use of a group approach to self-management served the dual purpose of addressing individual student needs while promoting independent and responsible behavior for all members of the class.     

学位与研究生教育自我评估的研究

作者在文中分析和探讨了学位与研究生教育自我评估的概念、基本特点、方法和技术,并对尚需探索与实践的若干重要问题提出了初步看法。