2002年诺贝尔物理学奖获奖的科学背景

20 0 2年诺贝尔物理学奖分别表彰了两项成果 ,一项是雷蒙德·戴维斯和小柴昌俊长期致力于宇宙天体物理学研究 ,在“探测宇宙中微子”方面取得的成就 ,这一成就导致了中微子天文学的诞生 ;另一项是里卡多尔·贾可尼在“发现宇宙射线源”,这一成就导致了 X射线天文学的诞生 .仅在几十年前 ,人们还认为宇宙是平衡而缓慢运动的 ,由于这些科学家的杰出贡献 ,这种思想只能停留在历史教科书中 .下面对这三位科学家所获得这一成就的科学背景作一介绍 .一、改变了人类认识宇宙的方式太阳为什么会发光 ?早在 19世纪 ,科学家们就曾对太阳的能量来源做…     

2002年诺贝尔自然科学奖

2002年诺贝尔物理学奖分别表彰了两项成果,一项是美国科学家雷蒙德·戴维斯和日本科学家小柴昌俊在“探测宇宙中微子”方面取得的成就,这一成就导致了中微子天文学的诞生;另一项是美国科学家里卡尔多·贾科尼在“发现宇宙X射线源”方面取得的成就,这一成就导致了X射线天文学的诞生.     

中微子及中微子实验的最新成就

本文从中微子的泡利假设到实际探测到中微子的几个重要实验,全面介绍了中微子及中微子实验的最新成就。由于2002年诺贝尔物理奖获得者雷蒙特·戴维斯(RmymondDavisJr)和小柴昌俊(MasatoshiKoshiba)在中微子探测研究方面所做的卓越贡献,中微子实验所开创的中微子天文学正处在21世纪科学研究的一个前沿。     

中微子的质量、混合和振荡研究

最近超神冈研究组的实验数据显示,中微子有质量、混合和振荡,ｍνｅ（００７±０．０４）ｅＶ．本文对中微子质量,中微子混合和中微子振荡作了计算,计算结果与超神冈研究组的实验数据相符     

大气中微子υ_μ振荡几率估算

据高能中微子的“长基线”实验计设参数 ,用数值实验常数相关联的唯象方法算出中微子质量数值 ,估算了中微子振荡几率 ,判断了 μ中微子υμ 与τ型中微子ντ 最可能发生振荡     

大气中微子vμ振荡几率估算

据高能中微子的“长基线”实验计设参数，用数值实验常相关联的唯象方法算出中微子质量数值，估算了中微子振荡几率，判断了μ中微子ｖμ与τ型中微子ｖτ最可能发生振荡。     

大气中微子vμ振荡几率估算

据高能中微子的"长基线”实验计设参数,用数值实验常数相关联的唯象方法算出中微子质量数值,估算了中微子振荡几率,判断了μ中微子vμ与τ型中微子vτ最可能发生振荡.     

中微子——一个热门的话题

最近一段时间里,人们经常谈及中微子,是因为近年来,物理学家发现了中微子的振荡特性,从而推断出中微子有质量(虽然很小)的结论,这是对标准模型的极大挑战,因而激起了人们极大的热情.不但高能物理、核物理还有天体物理和宇宙学都给予高度的关注,一门新的交叉学科--中微子物理正在蓬勃兴起.下面让我们讲述一下中微子的故事,还得从它的发现开始.     

大气中微子vμ振荡几率估算

据高能中微子的"长基线”实验计设参数,用数值实验常数相关联的唯象方法算出中微子质量数值,估算了中微子振荡几率,判断了μ中微子vμ与τ型中微子vτ最可能发生振荡.     

中微子——一个热门的话题

最近一段时间里,人们经常谈及中微子,是因为近年来,物理学家发现了中微子的振荡特性,从而推断出中微子有质量（虽然很小）的结论,这是对标准模型的极大挑战,因而激起了人们极大的热情。不但高能物理、核物理还有天体物理和宇宙学都给予高度的关注,一门新的交叉学科——中微子物理正在蓬勃兴起。下面让我们讲述一下中微子的故事,还得从它的发现开始。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.