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1.
为优选钙片中钙含量测定方法,对EDTA法、高锰酸钾法和分光光度法测定钙片中钙,从测定过程、与标示值比较和置信区间的比较三个方面进行了实验研究,结果表明3种方法均可用于钙片中钙含量的测定。综合测量结果准确度和方法的精密度因素,得出定量分析中试样的处理过程对测定结果产生的影响不容忽视。 EDTA法较其他两种方法具有操作简便、快速等优点,尤其是用直接称量取样的方法获得测量试样避免了稀释过程量器体积产生的误差,测定值较分光光度法和高锰酸钾法更接近标示值,可作为补钙药物中钙含量测定的首选方法。 相似文献
2.
贾静娴 《唐山师范学院学报》2001,23(2):24-25,42
甲醛法与蒸馏法是测定样品中氮含量的方法，结合碱厂的生产实际，进一步完善测定过程，将其应用于蒸氨废液中NH4^ 的测定，并将两种方法进行比较，对分析过程中应注意的事项加以说明，得出满意的结果。 相似文献
3.
目的:观察通心络胶囊对肾病综合征患者凝血酶活性、纤维蛋白原的影响.方法:配对及肝素治疗对照研究.受试者均接受血常规、尿常规、24h尿蛋白定量、血浆肝功能、血脂、肾功能、凝血酶活性、纤维蛋白原浓度测定.结果:口服通心络胶囊可改善高凝状态,抑制凝血酶活性,降低纤维蛋白原浓度.结论:对于肾病综合征患者在有效控制蛋白尿的同时,加服通心络胶囊可有效抗凝,预防血栓、栓塞并发症出现. 相似文献
4.
介绍了用气相色谱法测定白酒中己酸乙酯的两种定量方法:内标法和外标法,并分别对三个白酒样品进行测定。测定结果的RSD值依次为0.43%~0.86%和0.46%~1.40%,说明两种定量方法在检测白酒中己酸乙酯时结果无显著性差异,可将外标法推广到日常的白酒检测工作中。 相似文献
5.
本文分别采用标准法、微波消解法、催化刑法测定低浓度、高浓度废水的COD值，比较三种方法的优缺点。 相似文献
6.
采用高碘酸盐氧化法、旋光法、折光法、比重法和分光光度法对甘露醇水溶液进行含量测定,并对这五种方法进行了比较。结果表明,这五种方法的重现性和准确度都能满足测量要求;高碘酸法和比重法重现性好,但比较费时,而其他三种方法可以解决实验条件有限的情况下,快速、大批量测定甘露醇含量的问题。 相似文献
7.
本文介绍了一种利用微波加热，压力浸堤测定腐植酸类样品ＰＨ值的新方法，分析结果与标准方法相对照，没有显著性差异。测定速度高数十倍，该法具有操作简便，省时，省力，省电，重复性好，结果准确等优点，为其它样品的浸提提供了一种有效的，简便的经济。 相似文献
8.
屈景年 《衡阳师范学院学报》2001,22(6):21-24
根据热动力学的理论基础，提出两种热动力学研究方法：普遍热传导法和峰高比值法。并用LKB2107－Batch微量热计，测定乙酸乙酯皂化反应和蔗糖转化反应的热谱图，与用提出的这两种方法处理，所得结果与文献完全一致，证实了方法的可靠性。 相似文献
9.
介绍了计算电容的三种方法：定义计算法、模拟计算法、能量计算法，并且用这三种方法计算带缝长直半圆柱电容器的电容，得到了相同的结果。 相似文献
10.
测定蔬菜中铅含量的前处理方法的比较 总被引：2，自引：0，他引：2
本文通过大量试验对测定蔬菜中铅含量的三种前处理方法——HNO3-HClO4消化法、H2SO4-H2O2消化法、微波干灰化HNO3-HClO4法进行比较研究，证明微波干灰化HNO3-HClO4法具有氧化完全，药品用量少，无污染等优点。 相似文献
11.
A multi‐informant or multimethod approach has been suggested for use in educational evaluation and children's development assessment. However, in the study field of approaches to learning, most previous studies used one method to measure approaches to learning. In addition, compared with kindergarten and elementary children, younger children have received little attention. This study was dedicated to determining whether a multimethod approach (direct measure, teacher report, and parent report) was needed to assess preschool children's approaches to learning. A total of 713 preschool children were enrolled in this study. Correlations and multiple regressions were conducted to analyze the correlation among the three methods as well as their criterion validity based upon comparisons with an assessment of children's early childhood development. The results revealed significant but weak correlations among the three assessment methods. The direct measure of approaches to learning was more relevant to children's early childhood development than the teacher report and the parent report. The criterion validity of using the direct measure to assess preschool children's approaches to learning was also better than that of the teacher report and the parent report. Therefore, the direct measure was recommended for use in assessing preschool children's approaches to learning, and teacher report can be used as a supplement. 相似文献
12.
Mark R. Malone 《科学教学研究杂志》1984,21(7):755-768
This study assessed the effectiveness of conducting an elementary science methods course based on the Concerns Based Adoption Model (CBAM) upon the concerns and attitudes of pre-service elementary teachers (PSTs). PSTs were randomly assigned to one of three treatment groups. The three groups included a traditional science methods course, a course based on the theoretical development of concerns, and a course based on the actual measured concerns about teaching an elementary science methods course. Hypotheses were tested to determine if the traditional or either concerns based science methods course was more effective in improving attitudes or advancing PST concerns about teaching science. Two instruments—; The Stages of Concern Questionnaire and the Science Teacher Attitude Scales—; were used to gather pretest, posttest, and delayed posttest data. Analysis of study results indicated that PST attitude toward science and science teaching improved and concerns about teaching science shifted from lower to higher stages of concern in all three treatment groups as predicted by Concerns Theory. However, none of the methods courses proved superior in affecting concerns or attitudes of pre-service teachers. The study concludes that either one semester is too short a time to affect the desired shifts in attitudes and concerns, or that the diagnostic instruments currently available to measure concerns and attitudes are not sensitive or specific enough to measure subtle changes of interest in a research study. The author suggests that research instruments be developed specifically for preservice teachers for this purpose. 相似文献
13.
森林公安在职民警培训是提高森林公安队伍的执法水平和综合素质的重要手段和有效措施。要遵循“政治建警”、“科技强警”的原则和要求,以提高森林公安在职民警的综合素质和执法水平为中心,积极探讨培训的有效措施,提高培训质量。其措施为:一、针对森林公安机关承担的任务和森林公安队伍建设的现状,调整和充实培训内容;二、采取灵活的、行之有效的培训方法,增强培训效果。三、强化培训管理,促进培训基地的现代化、正规化建设。 相似文献
14.
蒋雪 《唐山师范学院学报》2011,33(3):156-158
量词对于以汉语为第二语言的学习者有着重要的作用。本文以名量词为研究对象,尝试探索对外汉语量词专题教学的方法,提出合理分级、合理分类、合理教学三个教学阶段,分析了三个阶段中要解决的问题,并且提出了＂顺口溜＂教学法等很有借鉴价值的教学法。 相似文献
15.
研究非绝热情况下精确测定冰的熔解热。与传统方法不同,测量时冰水混合物可以置于完全非绝热环境中。通过控制冰水混合物对环境的放热和从环境吸热相等来摒除环境对测量系统的影响。结果表明,通过选取合适的冰块质量、热水质量和温度三个基本要素,测量得到的冰的熔解热的值与公认值符合得很好。该文涉及到的实验方法和数据对冰的熔解热的测定具有重要参考价值。 相似文献
16.
Two studies were conducted for the purpose of validating an 18-item version of the Learner Empowerment Scale (LES) as a measure of student interest. The LES consists of three subscales that measure students’ perceptions of meaningfulness, impact, and feelings of competence. These three constructs are frequently identified by education researchers as dimensions of student interest. In Study One, there were no differences between the psychometric qualities of the 18-item measure and the 29-item measure. Additionally, the relationships between the two versions with measures of student motivation did not differ significantly from each other. In Study Two, relationships were explored between the three dimensions of the 18-item LES and students’ motives for communicating with their instructors. The results of these two studies provide preliminary reliability and validity for the shortened version of the LES as a measure of student interest. 相似文献
17.
How to select medical students who will be successful during different study phases as well as later in their profession is a difficult problem. This study focuses on the predictive value of students' entry-level skills measured by three multiple-choice science tests, the secondary school matriculation examination, and 'Learning-from-text' (LFT) tasks which were designed to measure critical thinking skills.The subjects (N = 109) were those medical students who were accepted in the University of Helsinki Faculty of Medicine in 1988. The results showed that the three science tests predicted the medical course grades. Further, a LFT task intending to measure the ability to pull together the essentials of a text predicted the pace of studying during both basic and advanced studies. LFT tasks intending to measure the deepest level of learning, i.e., the application of knowledge, predicted the grades obtained for the advanced courses. 相似文献
18.
Nicholas Vernadakis Eleni Zetou Efi Tsitskari Maria Giannousi Efthimis Kioumourtzoglou 《Education and Information Technologies》2008,13(3):167-183
The purpose of this study was to examine the effect of multimedia computer-assisted instruction (MCAI), traditional instruction
(TI), and combined instruction (CI) methods on learning the skill of shooting in basketball. Additionally, a comparison of
the students’ attitudes towards the MCAI and TI methods was made. Seventy-five middle school students of seventh and eighth
grade were randomly assigned into three teaching method groups: TI, MCAI and CI. Each group received ten 45-min periods of
instruction divided into three sections: (a) 5-min introduction, (b) 30-min instructional time and (c) 10-min questions and
review. Students took pre-, post-, and retention written test covering techniques and rules of the games. Participants in
the CI group also completed a post-test attitude survey towards the MCAI and TI methods. Two-way analysis of variances (ANOVA),
with repeated measures on the last factor, were conducted to determine effect of method groups (MCAI, TI, CI) and measures
(pre-test, post-test, re-test) on knowledge test. Paired samples t-test analyses were conducted to measure students’ attitude
towards the MCAI and TI methods. Post-test results indicated no significant differences between the groups concerning the
written test. Nevertheless, the attitude test scores of the CI group were more favourable to MCAI method than the TI method.
Retention test results showed that groups retained the knowledge acquisition. However, the combine method of instruction tended
to be the most effective on cognitive learning. 相似文献
19.
在信息化社会,计算机应用能力已成为衡量大学生综合能力的关键指标。学校培养人才的目的是为了缩短IT企业对人才需求的差距,在平时的教学过程中,应该将理论与实践紧密结合起来,坚持以计算机能力培养为核心进行教学。我们在分析计算机专业实验教学中存在问题的基础上,在教学内容、教学方法、实验考核制度和师资队伍建设方面不断地摸索、改革和实践,通过三年的实践,总结出了一套切实可行的方法,并取得良好的效果,满足当前社会的发展形势和对人才综合能力的需求。 相似文献
20.
赵明屏 《河北能源职业技术学院学报》2010,10(1):69-71
伏安法和惠斯通电桥法是物理实验中常用的两种测量电阻的方法。本文通过实验对伏安法和惠斯通电桥法分别测中、高、低三种不同阻值的电阻,并进行了客观的比较和分析。为实验中测量电阻时选取合适的测量方法提供一些参考。 相似文献