Spatial-temporal characteristics of siping urban expansion based on remote sensing and GIS

Based on the RS and GIS methods, Siping city is selected as a study case with four remote sensing images in 25 years. Indices of urban morphology such as fractal dimension and compactness are employed to research the characteristics of urban expansion. Through digital processing and interpreting of the images, the process and characteristics of urban expansion are analysed using urban area change, fractal dimension and compactness. The results showed that there are three terms in this period. It expended fastest in the period of 1979~1991, and in the period of 1992~2001, the emphases on urban redevelopment made it expended slower. And this is in agreement with the Siping Statistical Yearbook. This indicates that the united of metrics of urban morphology and statistical data can be used to satisfactorily describe the process and characteristics of urban expansion. © 2008 IEEE.

A STUDY OF SITE OCCUPATION OF EU-3+ IN ME2Y8(SIO4)6O2 (ME=MG, CA, SR)

Alkaline earth (Mg, Ca. Sr) yttrium silicate oxyapatites doped with Eu3+ show red luminescence with comparable intensity. In this system of phosphors, the Eu3+ ions enter 4f sites and 6h sites simultaneously according to the fluorescence spectra, in which

中学生强迫症状及其心理、环境危险因素和整合模型研究

Obsessive-Compulsive Symptoms, which are one of common factors effected on mental health of secondary school students, have been rarely studied at home and abroad. In accordance with the problems existed in these literature up till now, the thesis had mainly studied the measured tool, contents and structure, developmental features, psychosocial risk factors and integrated model of obsessive-compulsive symptoms from them by means of investigation with quetionnaires. The entire research was divided into three phases. 3185 students(age 14.68±1.75 years) were firstly measured with the 20-item Leyton Obsessional Inventory-Child Version(LOI-CV) at four secondary schools including six grades in Beijing city, which was applied to revise LOI-CV, and to study the structure and contents, developmental features and screen of obsessive-compulsive symptoms. Then, 216 subjects with obsessive-compulsive symptoms, paired with controls in the light of school, grade and gender, were investigated with 10 self-rating scales on obsessive-compulsive symptoms, anxiety, depression, personality, coping and attributional style, negative life events, parent's rearing style, family environment and life adaptation in school, and with an inventory on social demography. The results were used to explore psychosocial risk factors and integrated model of obsessive-compulsive symptoms. The third survey was only carried out, about two months after the second, among 264 subjects with obsessive-compulsive symptoms through MMOCI and Negative Life Event Scale for Adolescents, in order to probe into the integrated model. The research had mainly found: (1) LOI-CV can be used as a screen tool for obsessive-compulsive symptoms in urban adolescents in China; (2) Total screening-out ratio of obsessive-compulsive symptoms was 13.6% (male:15.0%, female:12.2%). The most common manifestations of obsessive-compulsive symptoms were hating dirt and contamination, doing things in exact manner, angry if someone messes desk, bad conscience but no one else, worry about cleanliness, repeated thoughts or words; the least were favorite or special number, spending extra time on homework, special number or words to avoid, talking or moving to avoid bad luck, fussy about hands. The checking and repetition, cleanliness and tidiness, general obsessions were more common forms than numbers-luck; (3) No differences were existed in serious degree of obsessive-compulsive symptoms, but the screening-out ratio in male was higher than it in female; (4) No differences were detected in the serious degree of obsessive-compulsive symptoms except the scores of cleanliness and tidiness among grades, but the screening-out ratio of the grades justly entering secondary school or going to graduate were higher than other ones; (5) The main psychosocial risk factors for obsessive-compulsive symptoms included anxiety, mother's over-protecting and over-interfering, fantasy, flexibility, self-actualization, peers relationship, sense of responsibility, negative life events, mother's occupation, help-seeking, and (6) The integrated model on psychosocial risk factors suggested that the possible developed and sustained mechanism of obsessive-compulsive symptoms was that personality, coping and attributional styles constructed the developmental diathesis foundation of obsessive-compulsive symptoms; negative life events were promoting factors of them. There was a dynamic interaction between personality and environmental factors. Negative emotion played a core role in the developmental process of them. The continued existence of obsessive-compulsive symptoms was related to pre-existed obsessive-compulsive symptoms and negative life events experienced by an individual. Therefore, this research not only let us get a deeper understanding of obsessive-compulsive symptoms and more entirely find out psychosocial risk factors, firstly applied diathesis-stress theory to comprehend the psychological mechanism of obsessive-compulsive symptoms and, moreover, elaborate and expand it, but also has more important practice significance of treatment, prevent and education for obsessive-compulsive symptoms in secondary school students.