农村留守儿童心理行为现状及其影响因素研究

To investigate the psychological and behavioral status and their influencing factors of children left behind in rural areas in China, 604 students were chosen from primary fifth grade, junior second grade and senior first grade in high schools in local villages and towns of Chongqing and Guizhou to complete some investegations. The results showed that children left behind actually had some internalizing problems including depression, state-trait anxiety, social anxiety, low self-esteem and some social problems in campus; however, they had no delinquency or aggression behaviors. Low parents’ educational level, low life standards, no-good parent-child relationship, the long years parent spent outside, the long time parent spent outside every year, the young age of child when his parent left him, the low contact frequency between parent and child when parent went out for work, all can be the influencing factors made child behave some psychological or behavioral problems. Children left behind need some appropriate psychological intervention, to improve parent-child relationship, to help release internalizing problems and amend interpersonal relationship at school. Several advices may be useful to improve psychological and behavioral problems of children left behind, which are for parents who work outside home not to work long to 10 years, or stay out for work more than 10 months per year, or left child to work when he is younger than two years old, or contact child more than one month after the last contact when work outside home, and you’d better contact child once a day. All of these could be helpful for children left behind to overcome some psychological or behavioral problems.

Microgravity Smoldering Combustion Of Flexible Polyurethane Foam With Central Ignition

Smoldering constitutes a significant fire risk both in normal gravity and in microgravity. This space experiment has been conducted aboard the China Recoverable Satellite SJ-8 to investigate smoldering characteristics of flexible polyurethane foam with central ignition in a forced flow of oxidizer. This configuration resulted in a combination of opposed and forward flow smolder. The microgravity experiment is rather unique in that it was performed at constant pressure, and with a relatively high ambient oxygen concentration (35% by volume). The smoldering characteristics are inferred from measurements of temperature histories at several locations along the foam sample. Particularly important is the discovery that there is a transition from smoldering to flaming near the sample end in the opposed smoldering. This transition seems to be caused by strong acceleration of the smoldering reaction. The observed transition serves to initiate a vigorous forward-propagating oxidation reaction in the char left behind by the smoldering reaction. The secondary char oxidation reaction propagates through the sample and consumes most of the remaining char. In forward flow smoldering, the oxidizer depletion by the upstream opposed smolder prevents an exothermic oxidation reaction from being established in the foam until this preceding reaction is completed. Once fresh oxidizer flows in the sample, the existing conditions are sufficient for a self-sustained forward smoldering reaction to take place.