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41.
Hamiltonian system for the problem on clamped Mindlin plate bending was established by introducing the dual variables for the generalized displacements in this letter. By separation of variables, the transverse eigen-problem was derived based on the sympletic geometry method. With the solved sympletic eigen-values, the generalized sympletic eigen-solution was derived through eigenfunction expansion. An example of plate with all edges clamped was given. The sympletic solution system was worked out directly from the Hamiltonian system. It breaks the limitation of traditional analytic methods which need to select basis functions in advance. The results indicate that the sympletic solution method could find its more extensive applications.  相似文献   
42.
This study compared private speech of children with ADHD and normal controls during problem solving and inhibition tasks. Thirty-two children (16 children with ADHD and 16 matched controls) aged 6–11 years participated. Consistent with previous studies, children with ADHD produced more task-irrelevant and task-relevant external private speech than control children during problem-solving tasks, but did not differ in their use of task-relevant internal private speech. During the inhibition/attention task (Continuous Performance Test-II), children with ADHD produced more task-relevant external and more task-relevant internal private speech, suggesting that they may have employed a less mature strategy to aid in self-regulation. The educational implications of the current study are that there should be an increased awareness of the developmental nature and functional significance of private speech and how private speech usage may differ in children with ADHD.  相似文献   
43.
In this paper we study the scaling behavior of nucleotide cluster in 11 chromosomes of Encephalitozoon cuniculi Genome. The statistical distribution of nucleotide clusters for 11 chromosomes is characterized by the scaling behavior of P(S) ∝ e^-αs' where S represents nucleotide cluster size. The cluster-size distribution P(S1+S2) with the total size of sequential C-G cluster and A-T cluster S1+S2 were also studied. P(S1+S2) follows exponential decay. There does not exist the case of large C-G cluster following large A-T cluster or large A-T cluster following large C-G cluster. We also discuss the relatively random walk length function L(n) and the local compositional complexity of nucleotide sequences based on a new model. These investigations may provide some insight into nucleotide cluster of DNA sequence.  相似文献   
44.
Novel high torque bearingless two-sided rotary ultrasonic motor   总被引:3,自引:0,他引:3  
Applications are limited at present because the currently available ultrasonic motors (USMs) do not provide suffi-ciently high torque and power. The conventional travelling-wave USM needs the bearing to support, which required lubricant. To solve the above problem, a bearingless travelling-wave USM is designed. First, a novel structure of the two-sided USM consisting of a two-sided teeth stator and two disk-type rotors is designed. And the excitation principle of the two-sided travelling-wave USM is analyzed. Then, using ANSYS software, we set up the model of the stator to predict the excitation frequency and modal response of the stator. The shape of the vibration mode was obtained. Last, the load characteristics of the USM are measured using ex-perimental method. The maximum stall torque and the no-load speed were obtained. The results showed that the characteristics of the two-sided USM are better than those of the conventional one-sided USM.  相似文献   
45.
Contemporary international higher education scholarship tends to focus on the global financial crisis,on massification,privatization,cross-border education,university ranking,and student mobility.However,few studies deal with the development of liberal arts programs around the world and they are often related to Western systems of higher education or that of the US,where liberal arts education has long been seen as a fundamental issue.Comparative studies,however,could help scholars to become aware of critical trends and reforms,also the impact they might have on a global society.  相似文献   
46.
Workbook reading achievement of five second-grade girls was assessed under two teacher-contact contingencies. Under one contingency, teacher contacts were made during on-task behavior. Under the other contingency, differential reinforcement of an incompatible behavior (DRI) was in effect, with teacher contacts contingent on students' hand-raising behavior. Both reading achievement and time on task were greater under the on-task contingency than under DRI for hand raising.  相似文献   
47.
This study examines sources of satisfaction, indicators of stress, academic performance, and reward structure in the academic careers of male and female faculty at a major midwestern state university. Faculty pairs were selected from five academic divisions. A total of 58 matched pairs were identified. Of these, 63 faculty responded, yielding data for 23 matched pairs. Subjects were mailed the Academic Career Development Survey, consisting of 144 items. Results indicated that self-reported physical and mental health, and professional and personal life satisfaction were high for both males and females. Both males and females placed high importance on their career and on marriage/other intimate relationships; however, both reported high levels of dissatisfaction with these factors. Gender differences were found in both satisfaction and type of stress reported; no gender differences were found in composite teaching and research performance indices. Salary data, obtained for 42 matched pairs, indicated similar salary levels for men and women. Results were discussed with respect to prior research on gender differences and the academic career.  相似文献   
48.
Since the 1970s, school effectiveness research has looked for process-variables filling the black box between mainly structural school features and cognitive outcomes in students. Two concepts came to the fore: school climate and school culture. Both concepts are currently used interchangeably, although it is open to debate whether both are actually the same thing. Because of the way culture and climate are defined and subsequently measured, we propose school culture is a better frame from which to study school effectiveness. This article goes through the premises of perceptual measurement usually overlooked in climate research, and we demonstrate empirically by means of very basic and simple methods and techniques that perceptual measurement and measurement based on assumptions are different approaches and might yield totally different results on an aggregated level. We conclude by demonstrating how culture can be probed and integrated in the models traditionally used in school effectiveness research in an advantageous and theoretically sound way.  相似文献   
49.
50.
The aim of this study was to understand adolescent mothers’ childbirth experiences. Semistructured interviews were conducted with participants recruited from a community-based program for adolescent mothers. Fourteen mothers described their birth experiences. Using a narrative analytic approach, responses were reconstructed into birth stories. Stories, condensed into poetic form, were compared and contrasted. Four unique categories emerged: connected births, surreal births, disconnected births, and disempowered births. Categories differed by agency, support, and emotional tone. Positive support was found in stories that portrayed high agency and positive affect, whereas problematic support was apparent in stories that conveyed passivity, frustration, and disappointment. This study has implications for tailoring childbirth education for adolescent mothers and can inform health-care professionals working with this population.  相似文献   
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