A motivational model of rural students' intentions to persist in, versus drop out of, high school.

Using self-determination theory, the authors tested a motivational model to explain the conditions under which rural students formulate their intentions to persist in, versus drop out of, high school. The model argues that motivational variables underlie students' intentions to drop out and that students' motivation can be either supported in the classroom by autonomy-supportive teachers or frustrated by controlling teachers. LISREL analyses of questionnaire data from 483 rural high school students showed that the provision of autonomy support within classrooms predicted students' self-determined motivation and perceived competence. These motivational resources, in turn, predicted students' intentions to persist, versus drop out, and they did so even after controlling for the effect of achievement. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

SDH自愈环网间互通问题的探讨

本文介绍在SDH环网大量采用的情况下,业务穿越两个甚至多个环网时,为提高环间互连节点和互连路径安全性所采用的双节点互连的保护方式.主要以单向通道保护环互连和复用段共享保护环互连应用为主.     

城市空间拓展的保护与控制

以哈尔滨为例,提出了城市设计对于城市历史性保护的态度及对拓展空间的控制原则,并提出城市生长的观点以理解城市空间形态的控制原则.同时,通过这些原则,探讨解决哈尔滨城市建设与空间拓展实践中的若干问题,以引导城市健康发展.     

信息系统风险评估实践

风险评估在信息安全保密体系建设中起着重要作用,是组织内开展基于风险管理的基础,它贯穿信息系统的整个生命周期,是安全策略制定的依据;也是按照PDCA改进组织安全保密体系的关键。论文在分析常见信息系统风险评估方法的基础上,提出基于应用系统、关注纵深防御和持续改进的风险评估方法,从而全面、系统地开展风险评估工作。     

小波变换在去除探地雷达信号直达波的应用

基于二维有向连续小波良好的方向选择性,对于探地雷达信号中的直达波进行了去除。通过对两个不同性质的埋地目标的处理,验证了这种方法的有效性。应用一维小波变换方法计算了探地雷达信号的瞬时参数,分析了几种瞬时参数夺于目标识别的作用,并且比较了直达波对瞬时参数识别目标的影响。     

连锁业务中远程数据传输的实现

为了展示连锁业务中远程数据传输的实现，以GSP管理软件中的总店和连锁分店之间的数据传输为例，讨论了连锁销售模式的企业如何选择合适的组网方式，在速度、成本、容错这3个方面都能够达到最佳。重点论述了在．NET实现远程数据传输的关键技术和具体实现方法，实践证明文中提出的方法是有效的。     

Why do lower educated people continue smoking? Explanations from the longitudinal GLOBE study.

This article describes the effect of educational level on the decision to continue smoking among 1,354 initially smoking participants (age≥20 years) in the Dutch GLOBE study. The effect of education continued smoking was explained from baseline information (1991) on smoking characteristics, individual characteristics, and environmental factors. Smoking status was reassessed after 6.5 years. Lower educated smokers more often continued smoking (odds ratio 2.09). Poor perceived health and earlier smoking initiation in lower educated groups were main predictors of educational differences in smoking maintenance. Educational differences in chronic illness, perceived control, neuroticism, and emotional support also contributed to the explanation of educational differences in continued smoking. These results have important implications for intervention programs and policy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

二流量试井工艺在文23气田的应用

针对文23气田供气紧张无法关井进行压力恢复试井的问题，运用不稳定渗流理论，引入了二流量不停产试井工艺方法。2000-2003年共三次对37口井进行了二流量试井，应用结果表明求解出的地层压力误差小于3％，渗透率和表皮系数在地质要求的允许误差范围内，基本达到与关井压力恢复试井等效的结果。该工艺为文23气田的开发调整、措施增产提供了有力的理论依据。     

建筑消防水池的探讨

建筑消防水池的储水量需要设计多大,才能做到既能满足建筑火灾时消防用水量的要求,又能达到科学、经济、节省投资的目的,这是当前建设、设计及消防部门关注的一个焦点,本文对当前实际工程中消防水池的设计情况进行了归纳总结,并以规范为指导,从因地制宜综合考虑消防水量、加强市政规划及消防水源建设等角度对建筑消防水池的设计作进一步的探讨。     

变形镁合金连续铸轧技术研究进展

变形镁合金材料具有良好的综合性能而被广泛应用,但由于其常温塑性较差导致变形镁合金材的加工变形困难.连续铸轧技术是一种短流程、近终成型板坯加工技术.综述了变形镁合金的合金体系、变形特点、加工方式和连续铸轧技术的工艺特点,探讨了变形镁合金连续铸轧技术的可行性,并介绍分析了国内外有关变形镁合金连续铸轧技术的研究现状和发展前景.