電是什么?

在大自然中,電以形形色色的姿態出現。其中最顯著、最普遍的,就是閃電。鄰近北極地帶(如蘇聯的北方)的居民很熟悉這些雄偉的現象:有時候,在夜間的天空上出現了紅、紫、黄、綠各種顏色的寬闊的、明亮的帶子。它們形成火燄般的帷幕,它們離奇地捲起而又展開。這是“北極光”,它的產生就是由於電。在高山上,當空氣相當乾燥的時候,可以看到“電光”。它們表現爲在金屬物體的尖端上的小小的火燄。古     

水使陆面降低

我們行星(指地球——譯者注)的表面在不停地改变着。會經是海底的所在,現在綿延着山脉。山脉也在被剝蝕而漸漸地变为小丘,然后又漸漸地变为平地。这种剝蝕当然是非常緩慢的。地球面貌的改变不是一年或一世纪的事,而是千百年的事。山脉的剝蝕同空气、水和溫度的变化乃至生物(微生物,而更重要的是植物)的作用有关。植物的根侵入岩石的裂縫后,使裂縫扩大起來,完成空气、水和太陽所引起的剝蝕作用,使大塊的石头剝离下來。然而,在所有的作用中,水对陆地表面的改变起的作用最大。著名的苏联地球化家B.H.維尔那德斯基院士写道:“一切的水,不論它呈液态、气态或固态,都处在毫無間断的运动之中,它充滿了作用能量,木身在不停地变化     

中国法律下的知识产权质押

多种原因造成了知识产权担保在发放信贷方面的重要性不如其他财产的担保。原因之一是知识产权具有一些特殊属性,一些潜在贷款人对这种财产属性缺乏了解。另一个原因是对许多知识产权的估价存在困难,相关法律在调整这些法定权利上的担保权益方面也不甚健全。尽管金融机构及其法律顾问已经越来越多地理解了知识产权担保借贷中的诸要素,但以知识产权担保的融资仍处在初期阶段。这是一个无论在法律领域,还是在信贷实践方面都很复杂的问题。立法者在回应专门立法需求以促进其发展方面也行动缓慢。这就进一步增加了用知识产权这种价值可能很大、但寿命又可能很短的财产做担保提供信贷的不确定性。     

等待胜利

阿拉斯加湾将会复原，但是复原速速度不会太快。今年3月24日凌晨，埃克森公司的瓦尔德兹号油轮运载着120万桶原油驶向公海，在威廉王子湾的暗礁上搁浅，而阿拉斯加湾从那时起要从生态恶梦中恢复过来得花多长时间呢?该地区的动植物是否能够恢复其原有面貌呢?     

令人窒息的飞行竞赛

这是世界上速度最快、最富有激情的运动。比赛过程可能只持续几分钟．但选手在场下所付出的艰辛却是我们难以想象的。     

爱因斯坦在长岛的那个夏天

1939年夏天,爱因斯坦到位于纽约东部的长岛度假.而我的祖父--大卫·罗斯曼,在那里经营着罗斯曼百货公司.6月的一天,爱因斯坦走进店里.尽管祖父一眼就认出了他,但还是把他当作一名普通顾客对待.     

德国的大学和科学

你们已经听说我是一个数学家。我的兴趣一直集中于科学本身，而不是它的科学机构和科学组织。不过，今晚我要谈的主要内容是关于德国的大学和科学研究机构，所以我恳求诸位理解我不是谈论这一主题的专家。我是通过我     

CSRP's Impact on low-income preschoolers' preacademic skills: self-regulation as a mediating mechanism

Based on theoretically driven models, the Chicago School Readiness Project (CSRP) targeted low-income children's school readiness through the mediating mechanism of self-regulation. The CSRP is a multicomponent, cluster-randomized efficacy trial implemented in 35 Head Start-funded classrooms (N = 602 children). The analyses confirm that the CSRP improved low-income children's self-regulation skills (as indexed by attention/impulse control and executive function) from fall to spring of the Head Start year. Analyses also suggest significant benefits of CSRP for children's preacademic skills, as measured by vocabulary, letter-naming, and math skills. Partial support was found for improvement in children's self-regulation as a hypothesized mediator for children's gains in academic readiness. Implications for programs and policies that support young children's behavioral health and academic success are discussed.     

Almost thinking counterfactually: children's understanding of close counterfactuals

Saying something "almost happened" indicates that one is considering a close counterfactual world. Previous evidence suggested that children start to consider these close counterfactuals at around 2 years of age (P. L. Harris, 1997), substantially earlier than they pass other tests of counterfactual thinking. However, this success appears to result from false positives. In Experiment 1 (N = 41), 3- and 4-year-olds could identify a character who almost completed an action when the comparison did not complete it. However, in Experiments 1 and 2 (N = 98), children performed poorly when the comparison character completed the action. In Experiment 3 (N = 28), 5- and 6-year-olds consistently passed the task, indicating that they made appropriate counterfactual interpretations of the "almost" statements. This understanding of close counterfactuals proved more difficult than standard counterfactuals.