未来10年为了可持续发展的地质科学

一、地质科学和环境 地质科学家进入环境领域相对较晚,在这一领域,工程师、地理学家、生物学家、气象学家、海洋学家和一些其它学科的科学家领先于他们。这已经对地质科学家在某些主要的应用科学团体和研究项目的地位和需     

Attention in preschoolers: associations with effortful control and motivation

The current study examined how individual differences in children's temperament and motivation relate to attention skills in children from economically disadvantaged families. A total of 73 mother-child dyads participated in this study. Children were between the ages of 3 and 5, and all attended a Head Start program. Using multiple hierarchical regression analyses, the hypotheses that effortful control (an aspect of temperament) and motivation would individually and collectively relate to attention skills were supported. The current study supports the importance of understanding attention as a multifaceted concept (Posner & Petersen, 1990) that relates to cognitive, socioemotional, and motivational systems. The utility of applying a systems approach to school readiness issues in children of poverty is discussed.     

面授培训班

本部自开设培育以来,受到广大读者的积极响应及拥护,在此,本部衷心感谢读者的信任与支持。现应更多的读者的要求,从2009年起,本部特开设面授培训班,本班所授技术均承诺真实可靠,包教包会。     

The rating of perceived exertion predicts intermittent vertical jump demand and performance

The aims of this study were (a) to assess the ability of the rating of perceived exertion (RPE) to predict performance (i.e. number of vertical jumps performed to a fixed jump height) of an intermittent vertical jump exercise, and (b) to determine the ability of RPE to describe the physiological demand of such exercise. Eight healthy men performed intermittent vertical jumps with rest periods of 4, 5, and 6 s until fatigue. Heart rate and RPE were recorded every five jumps throughout the sessions. The number of vertical jumps performed was also recorded. Random coefficient growth curve analysis identified relationships between the number of vertical jumps and both RPE and heart rate for which there were similar slopes. In addition, there were no differences between individual slopes and the mean slope for either RPE or heart rate. Moreover, RPE and number of jumps were highly correlated throughout all sessions (r = 0.97-0.99; P < 0.001), as were RPE and heart rate (r = 0.93-0.97; P < 0.001). The findings suggest that RPE can both predict the performance of intermittent vertical jump exercise and describe the physiological demands of such exercise.     

Correlations between serum and salivary hormonal concentrations in response to resistance exercise

The aim of present study was to examine the relationships between serum and salivary values of free testosterone, dehydroepiandrosterone, and cortisol before and after a session of resistance exercise. Twenty-eight healthy men (mean age 40 years, s = 4) participated in the present study. Serum and salivary samples were collected at rest and after a multiple-sets resistance exercise protocol, of approximately 25 minutes duration. Concentrations of free testosterone, dehydroepiandrosterone, and cortisol were measured using radioimmunoassay kits. No significant correlation was observed between serum free testosterone and salivary testosterone (r = 0.22 to 0.26, P > 0.05). Serum cortisol was significantly correlated with salivary cortisol before (r = 0.52, P = 0.005) and after (r = 0.62, P = 0.001) the exercise protocol. Serum and salivary concentrations of dehydroepiandrosterone were significantly correlated before (r = 0.68, P < 0.001) and after (r = 0.7, P < 0.001) exercise. The results of the present study suggest that even under exercise conditions, the salivary values of cortisol and dehydroepiandrosterone can reflect the behaviour of these hormones in blood. However, further studies are necessary to verify if salivary testosterone reflects the behaviour of serum free testosterone during resistance exercise.     

深层对话:课程研究国际化下的知识突破时机

深层对话的促成有赖三个时机:个人的批判分析与自我反思、由学术会议所引发的社会讨论、对学术会议中研究报告的再研究以获得心得.在这些时机中,由于参与课程研究的学者得以暂时远离熟悉的本土情境和规范,可以像个陌生人一样去质疑、评论本国和他国的课程事件与问题.因此,课程研究的国际化可以创造超越国家的课程对话空间,并引发知识上的突破.     

提高光伏转换效率的新设想

在太阳能实际应用中,较低的光伏转换效率是主要技术瓶颈。本项目围绕如何直接改进太阳能电池板的面形结构和特性,实现一种更加简捷有效的提高光伏转换效率的技术途径。借助照相机在镜头中采用凸透镜和镀增透膜来增加聚光性能的思想,本方案采用玻璃微珠所具备的短焦距聚光能力增大太阳光的接收角,同时选用溶胶凝胶膜层增加光线透过性。实验验证了玻璃微珠和溶胶凝胶膜层对提高光伏转换效率的科学可行性。实验结果表明,在宽光谱卤素灯大角度（70°）入射条件下,光伏转换效率相对玻璃基板提高了15．73％,充分验证了设计方案的原理可行性。本方法主要基于对太阳能电池玻璃盖板的结构改进,不需额外增加光学系统,结构简单,易于实现,设计思想具有独立创新性,在提高太阳能的光伏转换效率方面有着重要应用价值和发展前景。     

二次根式专题之思路与方法

在进行阶段复习时只有及时梳理思路，才能做到有的放矢．特别要强调解题后的反思，因为在这个过程中提炼出来的思想方法易于体会，易于接受．我们要从解题思路的探索、方法规律的概括过程中充分挖掘数学思想方法，拓展思维，领悟并逐步学会运用这些思想方法去解决问题，从而培养能力，全面提高数学素养。     

Lessons learned from single service point implementations

Interest in consolidating service points within health sciences libraries continues. This article proposes a definition of a library single service point and mentions some notable examples in academic health sciences libraries. The experiences of two of these libraries are summarized and compared, and the advice culled from those experiences is shared. The advice is in the form of sharing lessons learned, answering six frequently asked questions about combining services and staff under a single service umbrella. The article offers insights for other library staff considering this type of service reorganization.