论电压、电流两类负反馈反馈量表达式特点的必然性

剖析电压负反馈与电流负反馈对放大器性能所产生影响的差异,进而印证反馈量与输出量关系的特点是:对电压负反馈而言,反馈量与输出电压的正比关系与负载无关;对电流负反馈而言,反馈量与输出电流的正比关系与负载无关。     

负反馈放大器的输入、输出电阻简析

根据电路原理，应用分析方法导出电压串并联、电流串并联四种形式，负反馈放大器的输入、输出电阻关系式，能全面描述影响输入、输出电阻的电路参数，对于提高教学效果很有益处。     

碳纳米管优化负反馈放大器研究

本文给出了碳纳米管放大器的图形符号,以信号电能优化配置的新观点,设计了碳纳米管优化电压并联和电流联负反馈放大器,为碳纳米管的实际运用,提供了基本电路和前瞻性论述。     

碳纳米管优化负反馈放大器研究

本文绘出了碳纳米管放大器的图形符号,以信号电能代化配①的新观点,设计了碳纳米管优化电压并联和电流并联负反馈放大器,为碳纳米管的实际运用,提供了基本电路和前瞻性论述。     

差分-运放电流串联负反馈的理论计算与仿真分析

构建了直接耦合方式下的差分-运放电流串联负反馈放大电路,根据多级放大器增益的计算方法,计算了基本放大器的电压增益,进而得互导增益。另外采用微变等效电路方法,求解电路方程得到了反馈放大器的互导增益,两者满足负反馈放大电路中的基本关系。同时,启用仿真软件EWB,基本放大器和反馈放大器的仿真结果与理论计算一致。     

晶体管负反馈放大器的电压增益分析

本文讨论了多级晶体管放大器引入负反馈后,利用微变等效电路分析法对负反馈放大器的电压增益进行分析,以引入电压串联负反馈为例展开,并就分析值与仿真结果进行了对比。     

负反馈放大器回归比的测试

不论何种类型的负反馈放大器，只要在反馈环路某点处断开反馈环，测试出反馈放大器的回归比，就可方便地分析研究负反馈对放大器性能的影响．     

深度负反馈下电压增益的近似估算

本文主要介绍了1、反馈放大器的一般分析方法。2、应用深度负反馈下得到的虚短和虚断的概念对不同组态负反馈放大器电压增益的近似估算。     

负反馈放大器实验研究探讨

本文由电路分析出发，探讨了电压并联负反馈放大器实验研究中存在的错误，这些错误出现在某些实验教材中．并给出了正确的实验方法和电路．     

负反馈放大器的自激振荡产生原因及消除

１自激振荡产生的原因及危害根据参考资料的讨论可知单级阻容耦合共发射极放大电路在中频区输出与输入的电压相位差是１８０°。负反馈引入后可以改善放大器的一些性能：如降低放大倍数，提高放大倍数的稳定性，改变输入输出电阻等。但不管情况如何负反馈的反馈信号总是削弱放大器的净输入信号。但是当负反馈的反馈深度D＝０时，将会出现反馈放大电路在没有信号输入的情况下会有信号输出，这种现象违背了放大器的输入输出关系，使放大器变为自激振荡。那么负反馈是D＞１的，为什么会出现D＝０的呢？这是因为单级共射放大器在中频段满足输…     

What makes for effective feedback: staff and student perspectives

Since the early 2010s the literature has shifted to view feedback as a process that students do where they make sense of information about work they have done, and use it to improve the quality of their subsequent work. In this view, effective feedback needs to demonstrate effects. However, it is unclear if educators and students share this understanding of feedback. This paper reports a qualitative investigation of what educators and students think the purpose of feedback is, and what they think makes feedback effective. We administered a survey on feedback that was completed by 406 staff and 4514 students from two Australian universities. Inductive thematic analysis was conducted on data from a sample of 323 staff with assessment responsibilities and 400 students. Staff and students largely thought the purpose of feedback was improvement. With respect to what makes feedback effective, staff mostly discussed feedback design matters like timing, modalities and connected tasks. In contrast, students mostly wrote that high-quality feedback comments make feedback effective – especially comments that are usable, detailed, considerate of affect and personalised to the student’s own work. This study may assist researchers, educators and academic developers in refocusing their efforts in improving feedback.     

‘Now that’s the feedback I want!’ Students’ reactions to feedback on graded work and what they do with it

Since the introduction of the National Student Survey (NSS) in 2005, like many other institutions, the university where this study took place has expended substantial effort in improving the quality of feedback to students. However, despite much research, changes in pedagogical approaches and shifts in conceptual understanding related to feedback practice, assessment and feedback still receive the lowest satisfaction ratings in the NSS. Lecturers are discouraged when students fail to take note of their feedback, or sometimes do not collect assignments that have been marked. Understanding why feedback is not always acted upon remains an important area for researchers. This paper reports on an in-depth interview study with 14 final year undergraduates, reflecting on their perceptions of feedback written on marked assignments, by selecting examples of what they considered to be ‘good’ and ‘bad’ work. Findings suggested that emotional reactions play a significant part in determining how students will act on the feedback they receive, and the concept of ‘emotional backwash’ is introduced.     

负反馈放大电路反馈组态的快速判断

负反馈放大电路能够有效的改善放大电路的性能,掌握反馈放大电路反馈组态的判断方法,可以了解放大电路的性能特点,提高分析问题、解决问题的能力,提高学习效率,为以后的学习打下坚实的基础．     

用反馈网络法判断放大器的反馈性质

负反馈放大器以优良的性能得到了广泛应用，然而学生往往觉得判断反馈的正负性质比较困难，尤其是复杂电路。本文提出了放大器反馈性质的另一种判断方法——反馈网络法。该法直观、逻辑清晰，结合瞬时极性判断法，使反馈性质的判断方法多样化，非常灵活方便，使反馈性质的判断不觉得困难。     

反馈电路性质与类型的简易判别方法

利用反馈元件与电路输入、输出端的连接方式,来简化反馈类型的判别过程,并根据电压和电流的相互转换关系,采用“瞬时电流法”判别反馈电路的性质．通过对四种反馈电路的分析,来证明该方法的可行性和优越性．     

对负反馈电路判断的探讨

负反馈在放大电路中被广泛采用,文章从反馈网络、反馈极性、反馈组态等方面对负反馈电路进行了分析,得出了判断负反馈的方法和技巧,最后以实例说明负反馈电路的应用.     

Conventional or sustainable? Chinese university students’ thinking about feedback used in their English lessons

Feedback has been increasingly conceptualised as a dialogical process where students interpret the provided information through interaction with comment providers and use it to enhance their learning. A major challenge for the development of sustainable feedback is closely related to how students think about it. This study explored how 25 Chinese university students made sense of instructor and peer feedback following their English group presentations. The findings reveal that most of the participants perceived more judging and encouraging functions of feedback than its improving functions, which reflected their conventional thinking about feedback. Variation also existed in the perceived functions of instructor and peer feedback. Imbalanced power relations, face, group harmony and instructors’ feedback practice as well as students’ past learning and assessment experiences appeared to inhibit the participants from viewing feedback in a sustainable way. This study sheds light on college students’ complex thinking about feedback in a non-Anglophone context which has been neglected in the feedback literature, and has implications for educators and researchers in facilitating sustainable feedback in the Chinese context and the non-Chinese contexts where Chinese students study.     

与英语写作相关的同伴互评书面反馈研究

由于国内关于同伴互评对学生英语写作影响的研究相对匮乏,则本文通过量化分析方法和访谈对英语专业三年级学生的210份书面反馈进行探讨性研究,考察了反馈类型、纠错种类以及学生对同伴互评所持的态度。结果表明,同伴互评书面反馈类型呈现多样化,但绝大多数学生书面反馈属于纠正型。纠错种类主要是针对语法形式进行的纠正和修改,同时还兼顾文章的思想内容、统一性、连贯性等其他方面。学生书面评语及访谈表明学生对同伴互评的态度是肯定的,且本研究对写作教学中的同伴互评有一定启示。     

Feedback practices in a sample of children with emotional and/or behavioral difficulties

Abstract

This study examined two aspects of feedback in a population of children displaying emotional and/or behavioral difficulties. The study explored the agreement in teachers' and children's reports of positive and corrective feedback, as well as the role of teachers' beliefs concerning the child's sensitivity to feedback. Teachers' sensitivity ratings were positively correlated with teachers' reports of positive feedback, indicating that teachers may give differential feedback based on the teachers' perceptions of the child's sensitivity to feedback rather than specifically on performance indicators. Discrepancies between teachers' and children's reports of feedback were also evident. Given the critical role of feedback in the academic and social adjustment of children with emotional and/or behavioral difficulties, implications of feedback practices are explored.