La diferencia de sexo en la resolución de problemas aritméticos: un estudio transversal

Resumen

En este trabajo se estudia la diferencia entre los sexos en la resolución de problemas aritméticos verbales. Participaron 1.078 escolares de los grados 3.°, 4.°, 5.°, 6.° y 8.° de E.G.B. Se aplicó una prueba de 17 problemas aritméticos a los escolares de 3°, 4° y 5° en dos sesiones. También se aplicó una prueba de 4 problemas aritméticos a los escolares de 6.° y 8.° Los resultados indican que sólo en 8.° los varones son más hábiles que las mujeres resolviendo este tipo de problemas. Se hacen algunas consideraciones adicionales sobre los factores del contexto familiar y escolar que puedan incidir sobre los resultados.     

基于两个GFSRG的组合随机数发生器

随机数是蒙特卡罗(Monte Carlo)方法的关键因素.首先给出一种广义反馈位移寄存器发生器及其缺点,然后在此基础上提出一种基于两个广义反馈位移寄存器方法的组合随机数发生器,最后给出一些严密的统计检验,结果证明这种组合随机数发生器不失为一种较好的随机数发生器.     

Environmental literacy of youth movement members – is environmentalism a component of their social activism?

Youth-movements in Israel are non-formal organizations that educate for social and political involvement and provide a broad platform for youth involvement in the community. This study explored the question: does the social activism of adolescents who both elect for membership in youth movements and a leadership role of instructing younger members also reflect itself in environmentalism? In a survey of 1496 young instructors drawn from 15 official youth movements, findings on environmental literacy variables show youth are only generally knowledgeable about environmental problems; express ‘technical-optimism’ which leads them to limited concern for the environment; show limited recognition of the importance of environmental education, and show limited acknowledgment of the necessity for changes in personal consumerism. Findings also show that environmental issues are not on their mind since they are not a conversation topic with peers or family. Nonetheless, these youth also demonstrate strong self-efficacy to effect change; view themselves as role models for younger members; and express willingness to include environmentally-supportive activities within regular youth movement activities. Their valuing of nature also provides a foundation for building other environmental values. Further analysis shows how these findings can contribute theoretical and practical tools for incorporating sustainability within the youth movement framework, and help realize their potential for promoting sustainability in society.     

随机介质中光激发理论的数值方法

根据Jiang提出的随机介质模型,从Maxwell方程出发,结合速率方程和极化方程,并应用FDTD方法对方程组进行求解,着重讨论了求解的方法.     

关于Pro/E环境变量设置的探讨

在运用Pro/E设计软件将三维模型转换为工程图时,正确设置系统环境变量和工程图环境变量,可以快速绘制出符合我国国家标准的工程图。运用举例方法探讨Pro/E中由三维模型转化工程图时有关变量的具体设置,并使设置的变量在启动Pro/E的同时生效,从而提高绘制工程图的效率。     

弹性力学中混合变量的能量原理

建立了弹性力学中混合变量的虚功原理和虚余功原理,混合变量的最小势能原理和最小余能原理,混合变量最小势能的广义原理和最小余能的广义原理。同时,应用混合变量的最小势能原理于计算一复杂边界条件矩形板的弯曲。     

外商直接投资对中国就业增长的影响及其政策含义

外商直接投资影响我国就业增长,但在不同阶段影响程度将有所不同。但与区域特征结合后,外商直接投资对就业增长的影响更为显著。经济增长、工资水平、工业化程度是影响我国就业增长最重要的三个因素,且在我国加入WTO前后,影响程度有所改变。为了进一步促进就业增长,我国需适时和适度调整外资利用政策。