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11.
本文对秦始皇兵马俑博物馆室内采集的长短期降尘、大气悬浮颗粒物和彩绘漆层进行了SEM-EDX研究,在大气悬浮颗粒、短期和长期降尘中,含硫颗粒的粒径分别为0.9~22.8μm、1.0~29.0μm和1.2~37.7μm,多为石膏与粘土或石英以内部混合的状态存在。降尘中的附着型絮状硫酸钙多于大气悬浮颗粒物中,显示降尘和大气中的二氧化硫发生了累进的化学反应。彩绘漆层表面的坑和裂隙附近观察到原位生长的硫酸钙晶体,显示漆层材料或降尘颗粒物与大气二氧化硫之间的酸化学反应,可能是彩绘漆层表面受侵蚀形成微小坑和裂隙的原因之一。  相似文献   
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Measurement burst designs, wherein individuals are measured intensively during multiple periods (i.e., bursts), have created new opportunities for studying change at multiple time scales. This article develops a model that might be useful in situations where the functional form of short-term change is unknown, might consist of multiple phases, and might change over the long term. Specifically, we combine measurement of intraindividual entropy, a latent basis growth model, a multiphase growth model, and a growth model with covariates into a unified framework that could help accommodate the complexity of patterns that emerge in multiple time-scale categorical data streams. Empirical data from a longitudinal study of young children’s behavior during laboratory tasks designed to induce frustration are used to illustrate the utility of the proposed model for simultaneously describing intratask (short-term) change in self-regulation and developmental (long-term) shifts in intratask change.  相似文献   
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The present study investigated the effects of a special interactive dialogic reading method developed by Whitehurst et al. (1988) on deaf and hard-of-hearing children in Hong Kong. Twenty-eight deaf and hard-of-hearing children in kindergarten, first, or second grade were pretested on a receptive vocabulary test and assigned to one of three conditions, dialogic reading, typical reading, and control, with age and degree of hearing loss matched. After an 8-week intervention, the children were re-tested. The dialogic reading group had a significantly greater improvement in vocabulary scores than did the other two groups. Parent-child interactions of high quality and the use of pictorial materials are likely the key successful factors in the program. The educational value of this intervention is discussed.  相似文献   
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Abstract

The Chinese martial arts (Kung Fu) have existed for centuries and are generally accepted as being beneficial for health without much empirical data. The aim of this systematic review was to assess the health effects of “hard” Kung Fu styles by performing electronic and manual searches of the literature. The aspects of health and the Kung Fu style examined varied between most studies; in some cases, the martial art group consisted of practitioners of other martial art styles also. Of 2103 references identified, only nine papers were eligible and reviewed. All were observational studies, observing a range of health aspects possibly related to Kung Fu training or performance. Our findings suggest that there is no evidence that Kung Fu practice is associated with the prevention or treatment of any health condition. However, as a moderate- to high-intensity form of aerobic exercise, it may confer benefits similar to those attributed to other aerobic training modalities. However, this hypothesis remains to be tested in clinical trials. Physiological benefits (e.g., aerobic capacity and bone density) may be associated with long-term Kung Fu practice. Future research in this area should adopt experimental designs, clearly identifying eligibility criteria, testing and training protocols, and include health-related outcomes and documentation of adverse events, to advance knowledge in this field.  相似文献   
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Abstract

This study examined the influence of pitch dimensions in small-sided soccer games in shaping opportunities for performers to maintain ball possession, pass to teammates and shoot at goal. Fifteen amateur standard male participants (M = 21.87, σ = 1.96 years) played 5 v 5 small-sided soccer games in three varying pitch conditions (28 m × 14 m, 40 m × 20 m and 52 m × 26 m). Thirty sequences of play in each condition were selected for digitisation using TACTO software, allowing the capture of bi-dimensional displacement coordinate data of all players and the ball. The values of interpersonal distance between all attackers and immediate defenders and the relative distances of defenders to intercept a shot and a pass were computed as dependent variables. Results showed existence of fewer opportunities to maintain ball possession on smaller pitches, compared to medium and larger pitches. Conversely, the different dimensions set to the pitch did not influence opportunities for players to shoot at goal, or to perform passes to other teammates. By examining the specific spatial–temporal relationships of players and key-task constraints, the data from this study explain how effects of manipulating pitch dimensions of small-sided games might enhance opportunities for acquiring specific movement and decision-making skills.  相似文献   
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This study adopted a researcher-generated framework to analyze STEM activities demonstrated in primary students’ science projects in an annual extracurricular event held in Hong Kong. Ten students’ project reports were randomly selected from each of the three groups of 24 outstanding, 45 merit, and 68 consolation awarded projects. Content analysis was conducted to code the activities in each project. The coded information was then changed into numerical data for quantitative analysis. The results showed that, in general, more engineering and science activities than technology and mathematics activities were adopted by the primary students in their projects. More projects with the Outstanding Award conducted STEM activities than those projects with Merit and Consolation Awards, and significant group differences existed in the science and mathematics activities. Besides, science activities significantly positively related to engineering and mathematics activities. Furthermore, STEM-related content knowledge of discipline core ideas and crosscutting concepts were reported. This study sheds light on the pattern of STEM activities in students’ science projects, and has implications for promoting STEM integration in primary education.  相似文献   
19.
Community Level Factors and Child Maltreatment Rates   总被引:8,自引:1,他引:8  
Using census and administrative agency data for 177 urban census tracts, variation in rates of officially reported child maltreatment is found to be related to structural determinants of community social organization: economic and family resources, residential instability, household and age structure, and geographic proximity of neighborhoods to concentrated poverty. Furthermore, child maltreatment rates are found to be intercorrelated with other indicators of the breakdown of community social control and organization. These other indicators are similarly affected by the structural dimensions of neighborhood context. Children who live in neighborhoods that are characterized by poverty, excessive numbers of children per adult resident, population turnover, and the concentration of female-headed families are at highest risk of maltreatment. This analysis suggests that child maltreatment is but one manifestation of community social organization and that its occurrence is related to some of the same underlying macro-social conditions that foster other urban problems.  相似文献   
20.
This paper reports the findings of three studies of the counseling needs of international students at a medium sized University in the Midwestern region of USA. The studies were conducted over a period of five years (1977–83), and provide an historical perspective on the changes in student needs as well as in the programs designed to respond to these needs.  相似文献   
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