光线记录示波器常见故障及排除

光线记录示波器由于其结构的复杂性,使得在应用中经常出现一些故障.熟练掌握这些故障的排除方法是更好的应用这种测试记录仪器的关键所在.结合笔者多年的工作经验,列出了该仪器使用中经常出现的故障类型及处理方法,以供使用者参考.     

Early career patterns of men and women in British universities

The early career paths of 436 men and 162 women who took up lectureships in British universities in English, modern languages, or psychology in 1971–1973 were identified. Proportionately fewer women (61 percent) than men (80 percent) held a full-time post in a British university ten years after their initial appointment. Among those retaining a university appointment, relatively fewer women (8 percent) than men (18 percent) had advanced to the level of senior lecturer, reader, or professor. Factors that may have served to restrict the career development of women in British universities are discussed. There now is a higher proportion of women than in the past in the pool of graduates who are qualified for academic posts. However, the end to university growth makes it unlikely that the sex ratio of academics will shift substantially in the 1980s or the 1990s. Since promotion has become more competitive than it was in the past, the current sex ratio at senior levels of appointment may also remain relatively unchanged.This study was supported by funding under the Australian Research Grants Scheme. Unless stated otherwise, the university statistics cited in this article were derived from the analyses published annually by the Department of Science and Education. I am grateful to Sandra Lancaster for her assistance in data analysis.     

Social and Emotional Competence in Children of Depressed Mothers

The relations between maternal unipolar major depression and children's self-concept, self-control, and peer relationships were studied in a middle-class, predominantly white sample of 96 families. Each family included a target child between the ages of 5 and 10. Depressed mothers varied on whether or not the child's father also had a psychiatric disorder. Well mothers all had spouses with no psychiatric disorders. Analyses controlled for marital status, age, and sex of child. Children completed measures of self-concept and peer relations skills; teachers completed measures of self-control and a rating of popularity with peers. Results supported the multiple risk factor model in that fathers' psychiatric status and parents' marital status explained much of the variability in children's social and emotional competence. Maternal depression alone, in the context of a well husband/father, was only related to children having been rated by their teachers as less popular. Results are discussed in terms of possible mechanisms by which maternal depression may interact with paternal psychopathology and divorce in relation to children's social and emotional competence. The findings may further indicate that older children are more vulnerable to these multiple risk factors than younger children.     

Effects of SRSD college entrance essay exam instruction for high school students with disabilities or at-risk for writing difficulties

Reading and Writing - Strategies instruction has improved the writing of high school struggling writers in previous studies, including students with disabilities. This study examined the...     

Do Biologists’ Conceptions of Science as a Social Epistemology Align with Critical Contextual Empiricism?

From literature on understandings of the “nature of science” (NOS), we know that sometimes scientists and others that participate in teaching and mentoring in the sciences lack an informed view of the philosophical underpinnings of their discipline. In this study, we ask whether biologists who are also teachers or mentors for college students agree with the tenets of critical contextual empiricism (CCE), a social epistemology of science that foregrounds the importance of a diversity of voices in knowledge-producing communities. We used a Q-sort methodology to examine beliefs about social knowledge construction that are related to teaching science inclusively. Overall, we found that biologists-teachers held viewpoints somewhat consistent with the tenets of Critical Contextual Empiricism. Although participants shared many beliefs in common, we found two significantly different groups of participants that were characterized under the themes “knowledge is constructed by people” and “the truth is out there.” Overall, although participants believed a diversity of cognitive resources aids scientific communities, they failed to recognize the more nuanced ways certain social interactions might impact objective knowledge production. For one group, outside of a belief that collaboration in science is valuable, other social influences on science were assumed to be negative. For a second group, the search for universal truth and the separation of rational and social aspects was critical for scientific objectivity. We use the results of our Q-sort to identify areas for professional development focused on inclusive science teaching and to recommend the explicit teaching of CCE to science educators.

     

Two-choice,observational learning and reversal in the rat: S-S versus S-R effects

In Experiment 1, male rats were trained to press both bars in a two-choice apparatus and were then given observational training of a go/no-go discrimination in which the observed operation of two inaccessible, dissimilar bars by a hidden experimenter constituted S+ and S?. After discrimination was established, individual rats were permitted access to the two bars. Six of the seven rats consistently pressed the S+ bar on 10 test trials, but failed to reverse bar preference after observational training was reversed. In Experiment 2, nine naive males received the same observational training as in Experiment 1, but without any pretraining to press either bar. All rats pressed the S+ bar on initial test and did so consistently throughout the 10 trials. Six of these rats received reversal training of the go/no-go discrimination after the 10 test trials. As in Experiment 1, all rats failed to press the new S+ bar. However, five of six rats in another group, which received reversal trainingprior to any test trials, did reverse and press the new S+ bar. In Experiment 3, controls for possible confounding effects of overtraining trials were conducted. These manipulations had no effect; the rats tested before reversal still failed to press the S+ bar, and the rats reversed before testing all reversed or pressed the most recent S+ bar. That is, S-R learning predominated over S-S learning if active, though unreinforced, responding to a particular bar intervened. In contrast, however, a cognitive (S-S) interpretation of directed response learning was supported by the results of Experiment 4, in which the rats that learned the go/no-go discrimination without responding (only by auditory and light cues) failed to press the S+ bar consistently.     

Australian academics: Career patterns,work roles,and family life-cycle commitments of men and women

Men and women who held a full-time appointment at lecturer level and above in Australian universities in 1988 were compared in terms of the career paths they had followed, geographic mobility, domestic responsibilities, work roles, and levels of performance as an academic. Women had more often spent a period outside the workforce or in part-time employment due to childcare responsibilities. They more frequently had followed their partners to another city or country, they more often had been a tutor (a non-tenurable position) before becoming a lecturer. The survey indicated that substantially more women than men pursuing a full-time career as an academic were combining substantial household labour and childcare with employment. However, even when number of children and ages of children were considered, there were no differences between men and women in self-rated performance in such academic roles as research, teaching, and administration. The results are discussed with reference to the question of why in numerical terms there have been so few women academics in Australian universities.