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1.
对高阶微分方程f(n)(z)+An-1(z)f(n-1)(z)+An-2(z)f(n-2)(z)+…A1(z)f'(z)+A0(z)f(z)=0和f(n)+An-1(z)f(n-1)(z)+An-2(z)f(n-2)(z)+…+A1(z)f'(z)+A0(z)f(z)=F(z)的解进行了研究,其中Aj(z)(j=0,1,2…,n-1)和F(z)为单位圆△={z:|z|<1}内的解析函数,获得了解的超级和超级零点收敛指数的估计.  相似文献   

2.
本文研究了高阶线性微分方程f(k)+(Ak-1(z)epk-1(z)+Dk-1(z))f(k-1)+…+(A0(z)ep0(z)D0(z))f=0和f(k)+(Ak-1(z)epk-1(z)+Dk-1(z))f(k-1)+…+(A0(z)ep0(z)+D0(z))f=F(z)解的增长性问题,其中,pj(z)=a jzn+bj,1zn-1+…+bj,n,Aj(z)、Dj(z)和F(z)都是有限级整函数。针对pj(z)中aj(j=0,1,k-1)的幅角主值不全相等的情形,得到了方程解的增长级的精确估计。  相似文献   

3.
研究了高阶微分方程f(k)+A(k-1)(z)f(k-1)+A(k-1)(z)f(k-2)+…+A1(z)f'+A0(z)f=0和f(k)+A(k-1)(z)f(k-1)+A(k-1)(z)f(k-2)+…+A1(z)f'+A0(z)f=F(z)的亚纯解f(z)与其小函数ψ(z)的关系,得到了微分方程解取小函数的点的二二级收敛指数的精确估计,其中Aj(z)是亚纯函数。  相似文献   

4.
本文研究了高阶齐次线性微分方程f(k)+Ak-1(z)e^pk-1(z)f^(k-1)+Ak-2(z)^e^pk-2(z)f(k-2)+…+A0(z)e^pk(z)f=0和f(k)+(Ak-1(z)e^pk-1(z)+D(k-1)(z))f(k-1)+…+(A0(z)ep0(z)+D0(z))f=0解的增长性问题,其中Pjk(z)=ajz^n+bj,lz^n-1+…bj,n,Aj(z)和Dj(z)是有限级整函数。针对Pj(z)中aj(j=0,1,…k-1)的幅角主值不全相等的情形。得到了σ2(f)=∞。  相似文献   

5.
讨论一类非齐次高阶线性微分方程解的增长性,并得到精确结论,即证明当整函数F,Aj和s≥1次多项式Pj(z)(j=0,1,…,k-1)满足某些条件时,方程,f^(k)+Ak-1(z)e^Pk-1(z)f(k-1)+…+A0(z)e^P0(z)f=F的解满足λ2(f)=λ2(f)=σ2(f)=s.  相似文献   

6.
研究了高阶齐次线性微分方程f(k)+(Ak-1(z)e^pk-1(z)+Dk-1(z))f^(k-1)+…+(A0(z)e^p0(z)+D0(z))f=0解的增长性问题,其中pj(z)=ajz^n+bj,1z^n-1+…+bjn,,Aj(z),Dj(z)是有限级整函数。针对pj(z)中aj(j=0,1,…,k-1)的幅角主值不全相等的情形,得到了方程解的增长级的精确估计。  相似文献   

7.
关于代数微分方程的超越整解的增长性   总被引:2,自引:0,他引:2  
研究了如下代数微分方程a(z)f′^2 (b2(z)/f^2 b1(z)f b0(z)f′=d3(z)f^3 d2(z)f^2 d1(z)f d0(z)(这里a(z),bi(z)(0≤i≤2)和dj(z)(0≤j≤3)是多项式)超越整函数解的增长性,这类方程与有名的代数微分方程C(z,w)w′^2 B(z,w)w′ A(z,w)=0(C(z,w)≠0,B(z,w)和A(z,w)是z和w的3个多项式)有紧密的关系.详细地给出了第1个方程的整函数解的增长性与它的3个多项式的次数之间的关系.  相似文献   

8.
主要研究了一类非齐次线性复常微分方程f" e-zf' p1(z)e-zf=p2(z)解的增长性,其中p1(z)为级小于1/2的超越整函数,p2(z)为级小于1的整函数.  相似文献   

9.
本文得到函数类Gp(A,B)=f|f(z)=zp ∑∞m=p 1|am|zm,p∈N在单位圆E={z||z|<1}内解析且满足f(zzp)-1相似文献   

10.
利用Pang-Zalcman方法研究全纯函数微分多项式不取例外函数,得到了如下的正规定则:设■是区域D内的全纯函数族,对于任意的f∈■,f的零点重级至少是k+1,且满足L(z)≠z,其中L(z)=f(k)(z)+a1(z)f(k-1)(z)+…+ak(z)f(z)为f的微分多项式,ai(z)(i=1,2,…,k,k≥1)在D内解析,那么■在D内正规.  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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