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1.
1.概率与游戏 例1 图1是一个方格迷宫,甲、乙两人分别位于迷宫的A、B两处,两人同时以每分钟一格的速度向东、西、南、北四个方向行走,已知甲向东、西行走的概率都是1/4,向南、北行走的概率是1/3和p,乙向东、西、南、北四个方向行走的概率都是q. (1)求p和q的值; (2)问最少几分钟,甲乙两人相遇?并求出最短时间内可以相遇的概率.分析 (1)易知p=1/6,q=1/4;(2)最少需要2分钟,甲乙二人可以相遇(如  相似文献   

2.
数列是高中数学的重要内容,也是高考考查的重点,特别是递推数列,在数学问题中的广泛应用越来越引起人们的重视.下面就递推数列在排列组合与概率应用题中的应用作探讨,以供参考.一、递推式为an=pan-1 q(p、q为常数且p≠1)这类数列求通项方法为构造等比数列an p-q1或{an-an-1}.例  相似文献   

3.
<正>人们面对比较复杂的问题,有时无法通过统一研究或者整体研究解决,需要把研究的对象按照一定的标准进行分类并逐类进行讨论,再把每一类的结论综合,使问题得到解决,这种解决问题的方法就是分类讨论思想.分类讨论思想在解决问题时的一般步骤为:一是确定分类对象;二是确定分类标准;三是逐类、分级实施讨论;四是综合归纳结论.本文探究分类讨论思想在理解概念、求统计数据、求概率条件及求概率等“统计与概率”问题中的应用.  相似文献   

4.
恶性淋巴瘤是淋巴结及/或淋巴结外淋巴组织的恶性肿瘤.在西方国家,淋巴瘤的发病率占癌肿的第8位.在我国,占恶性肿瘤的第9位(男性)和第11位(女性),其中非霍奇金淋巴瘤(Nor-Hodgkins lymphomaNHL)的发病率每年以3%的速度增长.近十多年来,淋巴瘤的病因,发病机制,免疫学研究,分类及治疗有新的进展.NHL最常见的染色体异位为t(14;18),(q32;q21),t(8;14)(q24;q32).瘤细胞来源于淋巴细胞即B淋巴细胞、T淋巴细胞或自然杀伤(natural killer ,NK)细胞.瘤细胞表现分化停滞,呈单克隆性增殖失控.非霍奇金淋巴瘤是一组高度异质性的肿瘤.新近制定的"造血及淋巴组织肿瘤世界卫生组织分类"(WHO分类)综合肿瘤细胞形态学、免疫学表型、细胞遗传学和临床表现特征将非霍奇金淋巴瘤分为许多不同疾病类型.使诊断和治疗可能区别对待,更具有针对性、更趋合理化、个体化,以提高疗效、改善预后.1997.7-2005.6收治NHL62例,其中特殊表现的24例,现将其临床疗效观察报道如下:  相似文献   

5.
提起"或",大家并不陌生.生活中,多表示一种"选择关系".在数学上也只是一个小小的逻辑联结词,可以构成逻辑用语,还有何谈?非也,请看: 在数学上,对于命题p和命题q,用"或"可以联结成一个新命题:命题p或命题q.对于这个新命题,只要命题p和命题q都是假命题时,这个新命题"命题p或命题q"才是假命题;只要命题p和命题q中一个为真命题时,这个新命题"命题p或命题q"就是真命题.可以看到,让这个"或"命题是个假命题还真有点难,概率只有百分之二十五.这就是数学上的逻辑用语,"或"命题.此时,大家觉得"或"问题比较简单,可它有时很调皮.  相似文献   

6.
通过群自同构与图同构的方法,对4pq(p,q为互不相同的奇素数)阶二面体群的连通3度Cayley图的正规性进行了分类,并给出了除一种同构类情形不正规外,其余均正规的结论。  相似文献   

7.
在本文中的分数p/q,p,q均为正整数,当(p,q)=1时,称其为既约分数.我们说两个既约分数p1/q1,p2/q2是不同的,如果p1与p2,q1与q2这两对数中至少有一对不同.  相似文献   

8.
问题选解     
1.证明:数3~(105)+4~(105)能被13、49、181和379除尽.2.己知数A、B、C、P、q、r之间的关系式为:A:B=p,B:C=q,C:A=r,试写出比例式,A:B:C=□:□:□,空白处的表达式由p,q,r组成,而且必须是字母p,q,r的循环排列之一(即:如果p的地方写成q,q的地方写成r,而r的地方写成p,那么第一个表达式就变为第二个表达式,第二个表达式就变为第三个表达式,第三个表达式就变为第一个表达式).3.证明不等式:  相似文献   

9.
<正>1试题呈现2014年"华约"自主招生数学题第2题:一场比赛在甲乙两人之间进行,采用五局三胜制,已知甲赢一局的概率为p(p>1/2),设甲赢得这场2比赛的概率是q,求q-p取最大值时的p的值.该试题取材于高中生都熟悉的"五局三胜制",然而它不落俗套,提出了概率差的函数问题,具有较强的实际意义,本文将结合这道试题的解  相似文献   

10.
题目1 如果一个等差数列第p、q、r项分别为a、b、c,证明: (q-r)a+(r-p)b+(p-q)c=0. (引自[英]H.S.霍尔与S.R.奈特著《大代数》上册第四章等差数列练习四b). 题目2 在等差数列中,a_p=a,a_q=b,a_r=c.求证: (q-r)a+(r-p)b+(p-q)c=0. 题目3 设正数a、b、c为等比数列的第p、q、r项,试证:(q-r)lga+(r-p)lgb+(p-  相似文献   

11.
《海外英语》2007,(5):44-45
It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,  相似文献   

12.
《海外英语》2007,(4):36
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.  相似文献   

13.
王菲 《华章》2007,(12):273-273
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.  相似文献   

14.
裴水妹 《华章》2007,(11):196
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.  相似文献   

15.
16.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

17.
Today, Sunday morning, I sit thinking and typing at my computer. My thoughts are in my homeland, India and my body is in China. The body is here and mind there for a good reason. Mr. Hu is president and I am resident and both are in each other's countries (what a difference the absence of one small letter makes!). Mr. Hu will return in a few days and I will stay on longer.  相似文献   

18.
STORIES     
正A One day a pig went to the stable(马棚)to see his good friend,an oldhorse,and was going to stay there forthenight.Night came and it was time forsleep.The pig went into the straw heap(稻草堆)and lay comfortably.A longtime passed,but the horse was stillstanding there and did not move.Thepig asked the horse why he did not go tosleep."Standing like this is the begin-ning ofsleeping,"answered the horse.  相似文献   

19.
正1.Any fool can count the seeds in an apple.Only God can count all the apples in one seed.2.Happy families are all alike;every unhappy family is unhappy in its own way.3.Memories are the key not to the past,but to the future.4.Sometimes in the dark you see what you want to see.5.There is a great difference between  相似文献   

20.
正Scope and Policy The Journal of Chongqing University-English Edition(JCQU-E)is a peerreviewed journal publishing research articles in multiple disciplines of science and technology,covering civil and environmental engineering,chemical engineering,biotechnology,mechanical and electrical engineering,computer and data processing,mining,metallurgy,materials science,and interdisciplines thereof.  相似文献   

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