卤素动力学光度法研究：利用抑制效应测定痕量溴离子

基于稀硫酸介质，痕量溴对溴酸钾氧化孔雀绿反应的强抑制作用，建立了动力学光度法测定痕量溴离子的新方法。方法的表观摩尔吸光系数为４．０×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，灵敏度为１．９８×１０－１０ｇ／ｍｌ，用于玻璃、镁条和硫酸铵中溴的测定，结果满意     

对传统农村家庭教育功能变迁的思考

"民工潮"现象出现后,我国传统农村家庭教育功能呈现出新现象、新特点.本文以农村家庭模式划分理论为基础,进一步探讨了这一理论发展的趋向,并针对传统农村家庭教育功能变迁对子女社会化带来的不利影响,提出了若干建议与对策.     

中国国家形成于夏代吗?

中国国家形成于何时,自古以来无定论。自《中国史稿》问世后,才定于夏代。人类社会的发展,总是一个量变到质变的过程。夏代的生产力并无重大变化,仍然使用以石器为主的原始工具,不能使以血缘为纽带的氏族、部落和父系家长制家庭公社解体,一夫一妻个体家庭无法成为生产、消费的社会基本单位,更不能使之贫富分化而形成阶级。这样,夏代既不是“按地区划分国民”,也没有建立“公共权力”机构。     

辽东半岛早期渔业研究

渔业始终是史前时期辽东半岛重要生业之一。旧石器时代晚期已经出现了专业捕捞工具。进入新石器时代以来,因时地不同,渔业水平具有不平衡的特征。青铜时代以降,渔具与作业方式日臻成熟。新石器时代出现的海上捕捞,使渔业生产进入了一个新的阶段。即使是在农业产品较为充足的时期,渔业仍是重要的补充。虽然环境因素制约着渔业生产,但渔业始终保持着发展的态势,成为农业的重要补充或主要生业。     

Examining the effect of multiple writing tasks on Year 10 biology students’ understandings of cell and molecular biology concepts

This paper reports on a study that examined the cumulative effects on students’ learning of science, and perceptions of the role of writing in learning, when the students engaged in multiple writing tasks with planning strategy support. The study was conducted with Year 10 biology students who completed two consecutive units on Cells and Molecular Biology. A mixed method study was implemented using a pre-/post-test design with a focus on student performance on higher order conceptual questions, and semi-structured interviews with treatment students after the completion of each unit of study. Results from the quantitative component indicated that multiple, non-conventional writing had a significant benefit in helping students learn Molecular Biology. The results for the Cell unit were not so conclusive suggesting the strategies are most useful for novel content. The interviews with students demonstrated that they understood and engaged successfully with both the conceptual and linguistic demands of the tasks. These findings, taken as a whole, confirm that multiple writing tasks can support effective student learning, provided various pedagogical conditions are met.     

Components of Conceptual Ecologies

The theory of conceptual change is criticized because it focuses only on supposed underlying logical structures and rational process processes, and lacks attention to affective aspects as well as motivational constructs in students’ learning science. This is a vast underestimation of the complexity and diversity of one’s change of conceptions. The notion of conceptual ecology provides a context for understanding individuals’ conceptual change learning, as it is the environment through which all information is interpreted. This research investigated how high school students’ statements, made in answering questions, reflect selected components of their conceptual ecologies. Data for this study was collected from six interviews in which seven students took part. The data also include the science teacher’s profiles of each student, the students’ personal journals, their assignments, and their examinations and answers in class. The analysis presented will here include only those components that were represented in the discourse of the seven high school students who were interviewed. When students were asked questions, there was evidence of the engagement of the various components of conceptual ecologies. These components include: epistemological commitments, metaphysical beliefs, the affective domain and emotional aspects, the nature of knowledge, the nature of learning, the nature of conceptions, and past experience. Evidence from this study suggests that these components might function as constraints to learning. This study contributes to the field by expanding our knowledge of the components of high school students’ conceptual ecologies through its definition of the categories and themes associated with those components. In examining across the range of components, the study illustrates the variety and sources of science conceptions within high school students’ conceptual ecologies.     

经济转型、制度变迁与转型经济学研究范式及内容拓展

本文认为,纯粹的计划制度与纯粹的市场制度都是人类社会经济制度演化的极端情况,经济转型具有一般性和更为丰富的内容;西方主流经济理论只能解释转型社会的部分经济现象和经济问题,具有局限性;转型经济学研究必须在对计划经济理论与市场经济理论进行比较与综合的基础上,突破西方主流经济理论和传统计划经济理论的固有缺陷和约束,进行创新性扩展和重构,其研究范式和研究内容必须不断拓展;任何教条化既有理论观点的态度和做法,都不利于转型经济学理论体系的改进和完善.     

王安石翻案诗的政治解读及其诗史意义

王安石好作翻案诗,早期的翻案诗多在立意上翻新,包括转移视点执其一端立论和推陈出新两种主要方式。这一类翻案诗多为咏史诗,"有所为而为"的写作态度使之精深峭拔,最见荆公襟怀,必须结合王安石的政治关怀和当时的政治背景来解读此类诗作,泥于字句很容易与原旨产生偏离。王安石晚期的翻案诗创作多为诗法翻新,主要包括反用前人诗意及典故、章法上的推倒扶起和句法上的前后反覆三个方面。此类诗为宋诗新变指出了一条新的门径,以往文学史研究多强调荆公体或半山体对唐诗的回归,对此多有忽略。     

服务型乡镇政府的行政资源配置探析

随着中央"一号文件"的贯彻落实和农村税费改革的深入,特别是"工业反哺农业,城市反哺农村"方针的实施,农业与农村工作形势发生了巨大变化。在新形势下,如何促进乡镇政府转型,满足社会主义新农村对社会管理与公共服务的需求,是摆在我们面前的一个重大课题,而只有以服务型乡镇政府为视角重塑乡镇职能,并围绕职能的转变促进乡镇行政资源的优化配置,才可以从根本上解决阻碍服务型乡镇政府建设的瓶颈问题,从而促进新一轮乡镇机构改革与城乡经济社会的协调发展。     

电镜样品制备方法对ε-Cu析出相观察的影响

对同一样品采用双喷电解法和离子减薄法制备透射电镜薄膜样品,观察含铜钢中的ε-Cu析出相,结果表明：双喷电解法试样由于ε-Cu析出相与基体的腐蚀速率不同衍衬像反差较大,低倍观察较清楚,但高分辨像不清楚。经离子减薄后,由于ε-Cu析出相与基体共格,观察到的ε-Cu析出相与基体边界不清楚,但高分辨像的晶格条纹清晰显示真实的内部结构．通过能量损失像可得到析出相的分布情况。将离子减薄后的试样再用电解液进行腐蚀,用酒精清洗后电镜进行观察,可见大量的析出相颗粒,效果较好。