微车车桥壳体专用快速测试仪原理及实现

快速测试仪的工作原理是采用测距传感器扫描每个被检测孔的内圆柱面,根据采集到的数据经过相关数学公式的处理,得到每个被检测孔的实际圆心,并将相应的圆心连接成直线,再用几何公式计算得到被测孔系需要检测的项目．利用快速测试仪替代原用的测试设备,将微车车桥壳体检测从抽检改为全检,使检测精度可以得到稳定可靠的提高．     

滁菊对淹水胁迫的形态及生理响应

为研究滁菊对淹水胁迫的响应进行本实验.选取滁菊进行淹水处理,观察其外观形态变化,测定了淹水期间滁菊的各项生理指标变化.结果表明：随淹水时间的延长,滁菊叶片逐渐萎蔫发黄、干枯,最后出现植株死亡现象.电导率、可溶性糖含量、脯氨酸含量呈现先上升后下降的趋势且基本高于对照值,叶绿素整体呈现下降趋势且低于对照,变化程度反映了滁菊受淹水胁迫的伤害程度.     

Teacher commitment and its effects on student achievement in American high schools

This study explored the effects of teacher commitment on student achievement. Three teacher commitment dimensions of organizational, professional, and student commitment were derived. The three-dimensional teacher commitment measurement model was tested by a confirmatory factor analysis. Then, the relationships among individual and organizational variables, teacher commitment, and student achievement were analyzed by a 2-level hierarchical linear modeling method. As the results, the greater portions of teacher commitment and student achievement variances were within schools. The individual and organizational variables had differential impacts on each teacher commitment dimension. Finally, while teacher commitment effects on student achievement were differentially found depending on teacher commitment dimensions at the individual level, there was no evidence to support significant impacts of teacher commitment on student achievement at the organizational level.     

Predicting teachers' intentions to implement school-based assessment using the theory of planned behaviour

The theory of planned behaviour (TPB) was used to explore the Hong Kong teachers' intentions to implement school-based assessment (SBA) and the predictors of those intentions. A total of 280 teachers from Hong Kong secondary schools who had been involved in SBA were surveyed. Rasch-calibrated teacher measures were calculated for each of the 6 variables – affective and instrumental attitude, subjective norm, self-efficacy, knowledge, and intention – regarding SBA. The results of hierarchical multiple regression analysis revealed that instrumental attitude and self-efficacy made significant contributions to predicting intentions to implement SBA. These 2 predictors explained 55.2% of the variance in intentions. The other 3 variables, that is, affective attitude, subject norm, and knowledge, did not have significant predictive power on the formation of intentions to implement SBA. Possible explanations and implications of the findings are discussed.     

微库仑测氯仪操作条件的优化

通过实验选择微库仑测氯仪的最佳使用条件,转化率达到85%以上,测得样品的标准偏差为0.48,相对标准偏差为2.03%。该分析条件的优化使用,缩短了分析时间,提高了工作效率及对工艺生产指导的及时性。     

金纳米粒子的制备方法

金纳米粒子(AuNPs),其直径在1¹00 nm范围内,具有很好的稳定性、灵敏的光学特性、易进行表面修饰以及良好的生物相容性.本文重点介绍了AuNPs的制备发展过程、制备方法、形貌和应用前景.     

课程设计加强学生实践创新能力的教学改革探索与实践

作为测试技术基础课程的重要实践教学环节,课程设计是学生理论知识学习后一次全面、综合的实践。针对传统课程教学实践缺乏和创新能力培养的不足,采取多种举措进行教学改革探索与实践,使课程设计有效地培养学生实践创新能力。     

浅议投资性房地产两种模式的核算及影响

随着市场经济的发展和完善,房地产市场日益活跃,投资性房地产核算日趋普遍。投资性房地产持有和后续计量有两种核算模式：公允价值模式和成本模式。选择何种核算模式会直接影响企业的资产债务状况和盈利水平。无论是成本模式还是公允价值模式都有其自身的优缺点,不存在好坏之分,关键要看该模式是否适合于企业;企业在进行选择时,也要对各方面的影响因素进行综合考虑,从而选择出最适用于企业的核算模式。     

Measurement Bias Detection Through Factor Analysis

Assessing the correctness of a structural equation model is essential to avoid drawing incorrect conclusions from empirical research. In the past, the chi-square test was recommended for assessing the correctness of the model but this test has been criticized because of its sensitivity to sample size. As a reaction, an abundance of fit indexes have been developed. The result of these developments is that structural equation modeling packages are now producing a large list of fit measures. One would think that this progression has led to a clear understanding of evaluating models with respect to model misspecifications. In this article we question the validity of approaches for model evaluation based on overall goodness-of-fit indexes. The argument against such usage is that they do not provide an adequate indication of the “size” of the model's misspecification. That is, they vary dramatically with the values of incidental parameters that are unrelated with the misspecification in the model. This is illustrated using simple but fundamental models. As an alternative method of model evaluation, we suggest using the expected parameter change in combination with the modification index (MI) and the power of the MI test.     

Validation of the child sex abuse attitude scale through confirmatory factor analysis

A validation study was conducted on the Child Sex Abuse Attitude Scale (CSAAS) using confirmatory factor analysis (CFA) to examine factor structure. The CSAAS was developed based on Festinger's (1957) theory of attitude development resulting in a 4‐factor first‐order structure (cognition, value, affect, and behavior) and a single‐factor 2nd‐order structure (attitude). A sample of 215 school psychologists, members of the National Association of School Psychologists, responded to the CSAAS survey. CFA results supported the hypothesized factor structure of the CSAAS, thus indicating the plausibility of a 4‐factor 1st‐order and a single‐factor higher order structure of the CSAAS.