双电桥平衡条件及灵敏度的研究

从基尔霍夫定律和电桥灵敏度的定义出发,通过严格的理论推导,分析了电桥平衡条件及可测量条件,得出计算双电桥灵敏度的定量公式,讨论了影响灵敏度的各种因素,并对实验教学提出了一些优化建议。     

电桥灵敏度的研究

通过分析单臂电桥的绝对灵敏度 ( Sa)与相对灵敏度 ( Sr)和关系 ,运用 Δ-Y变换 ,得出了双臂电桥的 Sa 与 Sr 之间的关系 ,探讨了双臂电桥的比例臂的不同选择对电桥灵敏度的影响     

探讨惠斯通电桥的灵敏度与几种因素有关

用惠斯通电桥能够精确测量中等大小电阻,实验中在用电桥测量电阻时可以看出电桥的灵敏度:与电流计的灵敏度有关;与电源的电压大小有关;与四个桥臂的搭配及桥路电阻的大小有关;与限流电阻的阻值有关;还与电源所接的位置等因素有关。为提高电桥精确测量灵敏度,本文就对影响电桥灵敏度各种因素进行分析和探讨,以提高电桥测量的灵敏度。     

双臂电桥灵敏度探讨

仪器灵敏度概念在平衡测量、补偿测量中非常重要,它直接影响测量结果的误差和仪器配备等问题。在大学物理实验中,由于所配平衡指示器(如检流计)的灵敏度可能不是很高,所以这个问题比较突出。单臂电桥(惠斯通电桥)的灵敏度已在许多文献中加以讨论,而双臂电桥(开尔文电桥)的灵敏度比单臂电桥的低,讨论的也较少,本文着重对双臂电桥的灵敏度进行讨论。     

惠斯通电桥灵敏度的讨论

惠斯通电桥的电路如图所示: 电桥的灵敏度为:S=△n/((△Rx)/(Rx)) (1)△Rx 为电桥平衡后Rx的微小改变量,△n为Rx改变△Rx时,即电桥偏离平衡时,检流计指针偏转的格数。对同样的Rx和△Rx,△n越大说明电桥灵敏度越高。可见选用灵敏度较高的检流计,可以提高电桥的灵敏度。另外,由于检流计偏转量与流过它的电流的大小成正比,于是可以通过讨论电桥偏离平衡时,流过检流计的电流Ig的大小来讨论电桥的灵敏度。     

提高单臂电桥灵敏度的理论与实验分析

电桥的灵敏度与检流计和电源所接的位置有关,通过数学推导和实验测量得出结论:当D>0检流计内接时,电桥灵敏度较高;当D<0检流计外接时,电桥灵敏度较高。     

非平衡电桥灵敏度特性比较研究

灵敏度是非平衡电桥的一个重要性能指标.本文对单桥、半桥、全桥等非平衡电桥的不同桥路形态的灵敏度特性进行比较研究,以便实践中更好地应用非平衡电桥.     

双电桥灵敏度的探讨

一般的大学物理实验教科书中都安排了“用双电桥测低电阻”这个实验。但对双电桥灵敏度未作进一步的讨论,本文试图对此作些探讨。一、双电桥电路图三结出了它的原理性电路。其中民是被测电阻,RN是标准电阻,R1、R2、R3、R4是由标准电阻元件相成的电桥桥臂,G是检流计,电源E供给电流I0、I0的大小可以通过沿线电阻RP调节,其值可以通过电流表读出。流过R1、R2和RX中的电流分别为I1、I2和I3,其中I3远大于I1和I2。可由下式表达RX同其它量的关系。如果满足R1R3＝R2R4的关系,则即双电桥具有与单电桥相同形式的结果表达式。在实际…     

物理实验中单臂电桥灵敏度分析与测量

用单臂电桥测量电阻是普通物理实验中常用的一种电阻测量方法。依据单臂电桥的工作原理,通过理论分析和数学推导,分析了影响单臂电桥灵敏度的各种因素,给出了获得最大灵敏度时电桥应具备的条件。最后通过实验进一步验证了推导出的结论。     

单臂电桥线路灵敏度的计算及分析

本文推导了单臂电桥线路灵敏度的计算公式并用其对电桥实验作了分析研究     

Using Exploratory Bifactor Analysis to Understand the Latent Structure of Multidimensional Psychological Measures: An Example Featuring the WISC-V

Exploratory bifactor analysis (EBFA) represents a methodological advancement for implementing a bifactor model in exploratory factor analysis (EFA). However, little is known about how to properly employ the procedure. The current rotation criteria available for EBFA make it more likely to “get stuck” in local minima, contributing to possible group factor collapse, than more traditional EFA rotations. Thus, getting a proper solution is a more complex and involved process than typical EFA and may require a sensitivity analysis. This article examines EBFA through a sensitivity analysis and subsequent simulation of parameters thought to contribute to group factor collapse. Results support the use of sensitivity analysis, as the problematic variable was shown to greatly increase the likelihood of factor collapse. The hypothesis that estimation start values contribute to factor collapse was not supported. Accompanying R syntax for all analyses are provided to facilitate reproducibility.     

Combining Excellence and Ethics: Implications for Moral Education for the Gifted

In this article the current empirical research on morality and giftedness is reviewed with an emphasis on moral sensitivity. The component of moral judgment has been the most studied aspect in morality. Although high-ability students have been shown to be superior in moral judgment when compared to average-ability students, morality includes other components as well, such as sensitivity, motivation, and character. Furthermore, the critics of Kohlbergian research argue that moral reasoning does not necessarily lead to moral behavior. The gifted students might be able to give “correct” responses in the Defining Issues Test (DIT) test but their actual moral behavior cannot be predicted based on these test results. Hence, the limits of interpretation of these findings need to be acknowledged. The component of moral sensitivity is introduced with case studies regarding Finnish gifted students and Finnish Academic Olympians. The beliefs and values in academic work ethics of the Finnish Academic Olympians are discussed to give examples of how ethics can be combined with excellence in science. Some implications for the moral education of gifted students are suggested based on the research findings.     

Enhancing research through academic staff development

Abstract

In the past few years, research has been an increasingly important focus of academic staff development, but there is little documentation of this new area of development. The purpose of this paper is to describe the evolution over four years of a programme to develop research skills. The experience of planning and implementing this programme illustrates how changes in higher education and university priorities (such as amalgamations of institutions, increased pressures on staff, increased competition between institutions for funding, and universities’ growing corporatization) have interacted with staff development objectives to shape changes in the programme's purpose, format, mode of participation, and planning approach. A collaborative approach to planning is seen to be appropriate in the current climate, maximizing sensitivity to the distinctive needs of the various faculties, departments or schools. Current scholarly discussion is recognized as providing support for a move toward collaboration and context‐sensitivity.     

自适应零序电流继电保护研究

针对实际电力系统进行了常规零序电流保护与自适应零序电流保护的整定和灵敏度计算。由于自适应零序电流保护能够自动跟踪系统的运行状态,因此计算结果表明,与传统零序电流保护相比自适应零序电流保护其保护范围更大、灵敏度更稳定。     

Suprasegmental Phonology Development and Reading Acquisition: A Longitudinal Study

Previous studies implicate suprasegmental phonology in reading acquisition. However, little is known about how suprasegmental sensitivity develops or how it contributes to reading. Here, 130 Spanish primary-school children participated in this 2-year longitudinal study. Nonlinguistic rhythm, lexical-stress sensitivity and metrical-stress sensitivity, along with phonological awareness, vocabulary, nonverbal intelligence, and reading aloud, were assessed on five occasions. Results suggest that prosody abilities have different developmental trajectories and that prosody explains unique variance in reading beyond that explained by other factors. There was some evidence that the contribution of each prosody skill occurred at different phases in reading development. Nonlinguistic rhythm, lexical-stress sensitivity, and metrical-stress sensitivity assessed at the end of kindergarten, the start of Grade 1, and the end of Grade 1, respectively, predicted reading performance 6 months later. Nevertheless, sample size and reliability temper the conclusions that can be made. The implications of prosody skills for literacy development are discussed.     

试探检流计灵敏度的选用问题

介绍了各种类型检流计的结构特点及其灵敏度，探讨了如何根据测量结果对相对误差和绝对误差的要求来正确选择检流计的灵敏度问题，并给出了具体的计算方法。     

New perspectives in gaze sensitivity research

Attending to where others are looking is thought to be of great adaptive benefit for animals when avoiding predators and interacting with group members. Many animals have been reported to respond to the gaze of others, by co-orienting their gaze with group members (gaze following) and/or responding fearfully to the gaze of predators or competitors (i.e., gaze aversion). Much of the literature has focused on the cognitive underpinnings of gaze sensitivity, namely whether animals have an understanding of the attention and visual perspectives in others. Yet there remain several unanswered questions regarding how animals learn to follow or avoid gaze and how experience may influence their behavioral responses. Many studies on the ontogeny of gaze sensitivity have shed light on how and when gaze abilities emerge and change across development, indicating the necessity to explore gaze sensitivity when animals are exposed to additional information from their environment as adults. Gaze aversion may be dependent upon experience and proximity to different predator types, other cues of predation risk, and the salience of gaze cues. Gaze following in the context of information transfer within social groups may also be dependent upon experience with group-members; therefore we propose novel means to explore the degree to which animals respond to gaze in a flexible manner, namely by inhibiting or enhancing gaze following responses. We hope this review will stimulate gaze sensitivity research to expand beyond the narrow scope of investigating underlying cognitive mechanisms, and to explore how gaze cues may function to communicate information other than attention.     

有关溶出伏安法的探讨

溶出伏安法由于设备结构简单、测量的灵敏度高和测量范围广而受到分析工作者的青睐.针对该方法原理,分析了溶出峰电流的影响因素并对提高该法的灵敏度和分辨能力作了进一步的探讨.     

Far away and nearby: Holocaust remembrance and human rights education in Switzerland

The article considers how young people in Swiss schools are taught about the history and background of the Holocaust within the wider perspective of human rights education, as an important basis for education concerning democratic citizenship. Given the country’s specific history, for decades the Holocaust was not a matter of great interest in Swiss schools, or a topic that pupils often learned about as a part of their own history. Recently, however, sensitivity about historical incidents and the processes of the Third Reich has increased. Holocaust education has also become more important in the context of Swiss state institutional policy and non-governmental initiatives and has also become an issue in schools. This article includes an overview of relevant Swiss history and the current political situation, and a review of Swiss educational policies and especially of activities related to Holocaust remembrance and human rights education.     

零序电流互感器温度特性对漏电保护插头性能的影响

零序电流互感器的灵敏度和温度特性是一对相互制约的矛盾，漏电保护插头由于体积小，要求零序TA灵敏度很高，但如此一来，温度变化对漏电保护插头特性的影响就突显出来。经过大量的对比实验分析，引入零序TA抗温度突变特性λt概念，并通过试验找出降低λt值的有效途径。