稠油乳化输送试验环道装置研制及应用

为研究稠油乳状液在实际管道中的流动特性,弥补流变仪等仪器的缺点,研制了一种试验环道装置。利用该装置对胜利陈南稠油乳状液进行了输送试验,模拟了稠油乳状液在管道中的实际流动情况,并与流变仪测试结果进行对比。试验表明:含水率对稠油乳状液黏度影响很大,含水率高于40%时出现转相点,最佳含水率为45%;乳状液输送存在一个最佳混合流速,流速过高乳状液表观黏度有增大趋势;稠油乳状液表观黏度随温度的升高而减小,温度对O/W型稠油乳状液表观黏度的影响很小;在相同实验条件下,流变仪测试结果与环道试验结果规律一致,但表观黏度值偏小。     

简支混凝土工字梁超声测试中湿度效应的量化

为分析环境湿度对混凝土梁超声测试结果的影响规律,设计了室内自然环境下的混凝土工字梁超声测试试验,采集测试信号和对应湿度,将信号向量间的偏转角作为信号波动性的评估指标,反映湿度对超声信号的影响,构造信号的残差矩阵进行奇异值分解,提取左奇异向量中的湿度效应进行量化分析,通过去除信号在左奇异向量上的投影去除信号中的湿度效应。结果表明：超声测试信号的波形受湿度影响会发生时移和幅值变化;阶次越高的湿度效应分量在全部湿度效应中的占比越小;去除前5个湿度效应总量后,信号波动性均值可降低至原来的2%。     

食盐中氯离子测试的自我检验

讨论了造成同一食盐样品氯离子测试结果相对偏差较大的主要原因，提出并试验了相应的消除措施．试验证明：这些措施提高了食盐氯离子测试结果的准确度，保证了实验结果的再现性，完善了对产品氟离子测试结果准确度的检测．     

电流极线路对三极法接地电阻测量结果的影响

在采用三极法测量大型接地网接地电阻的试验中,电流极和电流极线路的布置方式是整个试验的基础,对测试结果起着决定性作用。对云南某变电站接地电阻进行现场测量试验,结果表明：电流极线路的长度对测试结果有影响,当架空线作为电流极线路时,避雷线有分流作用。     

成都裂隙性黏土流变特性试验

以成都裂隙性黏土为对象,进行一系列室内试验,探讨了成都裂隙性黏土的流变特性。通过三轴固结不排水蠕变试验,得到不同围压下各级偏应力水平的全过程蠕变曲线和应力—应变等时曲线,对试验结果做了讨论,并建立了蠕变方程。其中应变—时间关系采用伯格斯模型,应力—应变关系采用指数函数的蠕变方程,拟和曲线与试验曲线很好的吻合,较好地表达了土体的应力—应变—时间关系。     

车辆电容称重装置性能测试

针对目前车辆称重方法的不足,设计开发一种车辆电容称重装置,在介绍其结构设计和称重原理的基础上,对其静态性能和动态性能进行试验测试,重点讨论了测试过程,提供了相应的试验数据.测试表明车辆电容称重装置静态时具有较好的重复性,但也存在着一定的非线性误差及较大的迟滞性,直接影响着载荷检测结果;动态时加速度对动态称重影响较大,而速度、振动影响较小.     

基于多元概化理论的英语口语测试任务研究

基于多元概化理论,对某次口语测试所包含的朗读、听后回答、回答问题、听后复述四类常见的测试任务进行研究,重点关注不同类型测试任务的区分效果、测量精度和对总分的贡献程度。研究结果表明,偏封闭型、内容导向的测试任务相比偏开放型、技能导向的测试任务,在区分效果、测量精度和对总分的贡献上表现更好。     

让设计性综合实训成为科研成果产业化的试验田

高校教师的科研项目反映的是所在专业领域的前沿发展方向与水平,应该与本科阶段的实践教学相结合。在科研成果转化前的试验阶段,利用相同的试验原理与条件,将本科教学中的设计性综合实训与该试验结合起来,先利用课堂教学进行实训前的知识准备,将科研项目引进课堂,再后续进行设计性综合实训时,将科研成果转化前的测试作为实训内容,布置给学生,自主试验。由于科研成果是含有创新性质的,那么对科研成果测试的试验也具备创新性质,达到设计性综合实训的教学目的与效果。     

基于polyMAX的白车身锤击实验模态及灵敏度分析

针对传统模态分析方法的缺陷,采用polyMAX方法对某轿车白车身进行脉冲锤击法模态试验研究。首先建立白车身结构的测试系统模型,采用polyMAX方法进行试验模态特性分析,计算模态参数MAC值,并基此对车身结构进行灵敏分析。结果表明,模态测试系统满足精度要求,参数辩识结果有效可靠,结构参数的变化对车身结构的动态特性有较大影响,主要在于结构的质量和阻尼变化。     

模态测试技术在汽车零部件振动分析中的应用

模态测试技术是汽车结构动态设计与整车舒适性优化的重要方法。文章介绍了如何利用模态测试技术对汽车零部件的振动进行动态分析,通过试验获得了汽车车门的模态参数,并进行有效性验证和数据分析,结果表明该试验方法合理可靠,所获参数有效合理。     

儿童分类偏好的实验研究(英文)

本实验研究了3-4岁幼儿发展物体命名的可能性和给物体命名有怎样的分类偏好。本实验主要研究了两组儿童,每组10个人。一组的平均年龄是3岁。他们被分成两组,其中五个选择目标物体具有新名字的分类,另五个没有名字。另一组平均年龄是4岁,实验程序同上。实验结果显示儿童的倾向符合分类偏向。     

A probe into EFL learners’ emotioncy as a source of test bias: Insights from differential item functioning analysis

The development of unbiased tests is crucial in the arena of language testing in order to ensure validity. To date, studies of bias in language testing have mainly focused on factors such as gender, native language, or academic background, inter alia. However, bias may also result from psychological factors. Therefore, the present study investigates the role of English as a Foreign Language (EFL) test takers’ emotioncy, defined as the emotions evoked by senses that one holds for an entity, in their test performance. Specifically, this study aimed to examine emotioncy for the form as well as the meaning of 20 words to find out whether it can lead to differential functioning of the items on a vocabulary test. To this end, two emotioncy scales and a vocabulary test were designed. Then, based on the data collected from 235EFL students, the participants were bisected into the Low-Group and the High-Group, once based on their emotioncy scores for each word form and then based on their emotioncy scores for each word meaning. Subsequently, Rasch model-based Differential Item Functioning (DIF) analysis was performed across the two groups. The results showed that the vocabulary test items functioned differentially across the two groups in both form and meaning classifications, favoring the High-Group. Therefore, the study provides evidence for emotioncy as a psychological source of test bias and discusses implications for language testing stakeholders.     

A theoretical framework for the exploration of causes and effects of bias in testing

Test validity has been the predominant paradigm underlying much of the research into test bias. If we are interested in identifying causes of bias and determining its effects on test scores, validity may not be the best paradigm. In this article, a simple theoretical framework is presented in which bias can be seen to affect validity, but is not defined by it. Bias is seen instead as a multifaceted aspect of tests and of test takers. Some of the implications of this model for understanding the causes and effects of bias are then explored.     

The Multidimensionality of Measurement Bias in High-Stakes Testing: Using Machine Learning to Evaluate Complex Sources of Differential Item Functioning

Test developers and psychometricians have historically examined measurement bias and differential item functioning (DIF) across a single categorical variable (e.g., gender), independently of other variables (e.g., race, age, etc.). This is problematic when more complex forms of measurement bias may adversely affect test responses and, ultimately, bias test scores. Complex forms of measurement bias include conditional effects, interactions, and mediation of background information on test responses. I propose a multidimensional, person-specific perspective of measurement bias to explain how complex sources of bias can manifest in the assessment of human knowledge, skills, and abilities. I also describe a data-driven approach for identifying key sources of bias among many possibilities—namely, a machine learning method commonly known as regularization.     

一种具有语音播报功能的IC测试仪设计

为了满足数字电路实验教学对IC测试的需求,以两片单片机为核心,设计了一种IC测试仪,该测试仪能测试常用的74LS系列IC,并能对测试结果进行显示和语音播报,具有使用便捷、性能可靠、界面友好等优点,适合在数字电路实验中使用.     

Nouns Mark Category Relations: Toddlers'' and Preschoolers'' Word-Learning Biases

Recent research suggests that preschool children approach the task of word learning equipped with implicit biases that lead them to prefer some possible meanings over others. The noun-category bias proposes that children favor category relations when interpreting the meaning of novel nouns. In the series of experiments reported here, we develop a stringent test of the noun-category bias and reveal that it is present in children as young as 2 years of age. In each experiment, children participated in a 5-item match-to-sample task. Children were presented with a target item (e.g., a cow) and 4 choices, 2 of which belonged to the same superordinate category as the target (e.g., a fox and a zebra) and 2 of which were thematically related to the target (e.g., milk and a barn). In Experiment 1 we demonstrate that novel nouns prompt preschool children to attend to superordinate-level category relations, even in the presence of multiple thematic alternatives. In Experiment 2, we ascertain that the bias is specific to nouns; novel adjectives do not highlight superordinate category relations. In Experiment 3, we demonstrate the noun-category bias in 2-year-olds. The nature and utility of the noun-category bias are discussed.     

Cross-Modal Transfer of Shape is Difficult to Demonstrate in One-Month-Olds

We tested 1-month-olds for cross-modal transfer of shape between touch and vision using a procedure described by Meltzoff and Borton, but including controls for side bias and stimulus preference. In Experiment 1 (N = 48), infants' looking times to smooth and nubby visual stimuli were not influenced by previous oral exposure to one of the shapes during the preceding 90 s, except for an effect on the first test trial in one group; this effect could have been due to limited cross-modal transfer, to Type 1 error, or to side bias, possibly interacting with a small stimulus preference. The failure of that effect to replicate in a group (N = 16) with less side bias (Experiment 2) suggests that it was not due to cross-modal transfer. Experiment 3 (N = 32), an exact replication of Meltzoff and Borton's experiment, also failed to yield evidence of cross-modal transfer. Overall, there is not good evidence that 1-month-olds can transfer information about these shapes from touch to vision. Future studies exploring the ability to transfer information about other shapes will be easier to interpret if they include controls for side bias and stimulus preference.     

Gender Bias in the Prediction of College Course Performance

Is the relationship of college grades to the traditional predictors of aptitude test scores and high school grades different for men and women? The usual gender bias of underpredicting the grade point averages of women may result from gender-related course selection effects. This study controlled course selection effects by predicting single course grades rather than a composite grade from several courses. In most of the large introductory courses studied, no gender bias was found that would hold up on cross-validation in a subsequent semester. Usually, it was counterproductive to adjust grade predictions according to gender. Grade point average was predicted more accurately than single course grades     

Small‐Sample Equating Using a Synthetic Linking Function

This study addressed the sampling error and linking bias that occur with small samples in a nonequivalent groups anchor test design. We proposed a linking method called the synthetic function, which is a weighted average of the identity function and a traditional equating function (in this case, the chained linear equating function). Specifically, we compared the synthetic, identity, and chained linear functions for various‐sized samples from two types of national assessments. One design used a highly reliable test and an external anchor, and the other used a relatively low‐reliability test and an internal anchor. The results from each of these methods were compared to the criterion equating function derived from the total samples with respect to linking bias and error. The study indicated that the synthetic functions might be a better choice than the chained linear equating method when samples are not large and, as a result, unrepresentative.     

‘Consider the Opposite’ – Effects of elaborative feedback and correct answer feedback on reducing confirmation bias – A pre-registered study

Unbiased reasoning is considered an essential critical thinking skill that students need to possess to face the future challenges in their work and life. Confirmation bias, which is the tendency to selectively attend to information that is consistent with held beliefs, presents a significant thread to unbiased reasoning. An effective strategy to reduce confirmation bias is the ‘consider-the-opposite’-strategy (COS). The central question of this pre-registered study was whether providing elaborative, worked example feedback after COS practice would lead to a better performance on previously practised and transfer tasks than correct-answer feedback. Participants were 132 university students who took a confirmation bias pre-test, watched an instructional video on COS afterwards and next received either worked example feedback or correct answer feedback on practice tasks, practised only, watched the instruction only or received no treatment. Finally, all participants took a learning test assessing their skill to avoid confirmation bias, and a transfer test assessing whether they could apply this acquired skill to problems containing other biases. Results revealed no differences on the learning test between both feedback conditions, but students who received feedback scored significantly higher on the confirmation bias problems than students who did not receive feedback. We carried out our pre-registered analysis plan, but due to the low reliability of particularly the pre-test, we carried out an additional exploratory analysis on subsets of post-test items and a subset of transfer test items. Results on learning revealed the same pattern as the planned analyses. However, we found no differences between any of the conditions on transfer.