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1.
等差数列的前n项和Sn是关于n的过原点的二次函数,其标准形式为S n=An^2+Bn(A、B∈R),等比数列的前n项和的标准形式为S n=A-Aq^n(A∈R).对于形如(an+b)·q^n(a、b∈R,q≠1)的数列,其前n项和的标准形式为Sn=A+q^n(Bn-A).  相似文献   

2.
定义k~1型广义Fibonacci数列,研究其通项与性质;结合相关文献方程和解的特点,猜想并证明了x^2+麟y—y^2+1=0(k∈N*)这一类不定方程有且只有k~1型广义Fibonacci数列形式的非负整数解.  相似文献   

3.
设IFq是一个q元有限域,v是一个自然数,1≤i≤v,在这篇章中,我们证明了以下公式:∑a≤j1≤j2…<ji≤vJ1,J2,…ji∈Nqj1 j2 …ji=q^i(i 1)/2[vi]q,这里[vi]q是Gauss系数。  相似文献   

4.
主要研究了单位圆盘上Hilbert值Dμ,q得到了Hilbert值Dμ,q函数的Lipschitz条件,若f(x)=∞∑n=1xnz^n∈Dμ,q,0〈μ〉1,q〉2n/μ,则有Ф(z)-∞∑n=1||xn||z^n∈Lipγ.这推广了标量值Dμ,q函数的性质,在此过程中,我们利用了Rademacher函数序列的知识.  相似文献   

5.
环是指具有单位元的结合环,而一般环是指有或没有单位元的结合环.一般环I称为是强Clean的,如果I中每个元素α具有下述的形式a=e+q,其中e^2=e∈I,q∈Q(I)={q∈I|q+p+qp=p+g+pg=0对某个P∈I}且eg=qe.这一概念是Nicholson中强Clean环概念的真推广.强Clean一般环的刻画给出了.基于此,证明了强Clean一般环的单边理想也是强Clean的,并证明了如果I是强Clean一般环,那么,对于任意x∈I,I在x处的局部环Ix也是强Clean的.特别地,强Clean一般环的角落子环eRe总是强Clean的对于任意的e^2=e∈I.这推广了Chen中的主要结果.  相似文献   

6.
引理在等差数列{a_n}中,若p,q,m∈N~*,且p+q=2m,则a_p+a_q=2a_m.有穷等差数列的奇数项的和用S_奇表示,偶数项的和用S_偶表示.性质1若等差数列{a_n}共有2k-1(k∈N~*,且k>1)项,则中间项a_k=S_奇-S_偶,当S_奇  相似文献   

7.
由文[1],不妨记有一根为方程x^2+px+q=0,某根n次方的方程(n∈N)为x^2+pnx+qn=0,约定p0+q0=1,p1=p,q1=q,则有  相似文献   

8.
本文主要利用三角函数的倍半角公式和一元三次方程的求根公式对于 2πn ,0 < n ≤ 10 ( n ∈ Z )的余弦值进行了讨论,并证明了 cos 2πn(n=7,9 时)不能被表示成 p q 3 r的形式,其中p,q,r∈ Q。  相似文献   

9.
一、递推式为an+1=pan+q(p,q为常数)型 【例1】已知数列{an}中,a1=1,对于n〉1(n∈N^*)有an=3an-1+2,求an  相似文献   

10.
等差数列{an}具有如下性质:若m,n,P,q∈N*,且m+n=p+q,则a_n+a_n=a_p+a_q.利用等差数列的通项公式a_n=a_1+(m-1)d,n∈N*容易证明.直接用这一性质解题可化难为易,化繁为简.  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.
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/  相似文献   

13.
《海外英语》2007,(5):10-11
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?  相似文献   

14.
《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   

15.
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   

16.
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   

17.
18.
1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…  相似文献   

19.
《海外英语》2007,(4):8-9
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!  相似文献   

20.
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.  相似文献   

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