加权Bergman空间上的等价范数

对可允许的权函数ω：[0,1）→（0，∞），加权Bergman空间L^Pα↓，ω上的范数定义作‖f‖P，ω＝｛∫D|f(z)|^Pω(|z|)dm(z)｝^1/p。我们证明，对0＜p＜∞和f∈H（D），‖f‖p,ω-|f(0)| ｛|∫′（z）^pΨ(|z|)^pω(|z|)dm(z)｝^1/p。由此我们给出函数算子Tg:f→∫z↑0↓f(t)g′(t)dt在L^Pα↓，ω上有界的一个充分条件。     

信号处理原理综合练习2

5　证明题1)证明 :(f1(t) f2 (t) ) f3(t) =f1(t) (f2 (t) f3(t) )2 )证明 :复信号的虚实分量应满足 :(1)F(fτ(t) ) =12 (F(ω) +F (ω) )(2 )F(fi(t) ) =12j(F(ω) -F (ω) )答案1)证　 (f1(t) f2 (t) ) f3(t) =∫ ∞-∞(∫ ∞-∞f1(λ)f2 (τ -λ)dλ)f3(t-τ)dτ =∫ ∞-∞ f1(λ) (∫∞-∞ f2 (τ -λ)f3(t-τ)dτ)dλ =∫ ∞-∞ f1(λ) (∫∞-∞ f2 (τ) f3(t-τ -λ)dk)dλ =f1(t) (f2 (t) f3(t) )2 )证　(1)F(fτ(t) ) =F(f(t) +f (t)2 ) =12 (F(f(t) ) +F(f (t) ) ) =12 (F(ω) +F (ω) )(2 )F(fi(t) ) =Ff(t) -f (t…     

电路中三要素公式的改进形式

电路中的三要素公式常用于直流电源作用下一阶电路响应的计算。若把三要素的公式稍加改进,可使求解正弦信号作用下一阶电路的响应更为方便。正弦信号作用下一阶电路的响应形式为 f(t)=f_mcos(ωt+φ)+Ke~(?) (1)(1)式由暂态分量Ke~(-1/r)和稳态分量f_mcos(ωt+φ)两部分组成。其中K由电路的初始条件确定,K=f(0)-f_mcosφ。(1)式与三要素计算公式f(t)=f(∞)+[f(0_+)-f(∞)]e~(?)比较便知 f_mcos(ωt+φ)=f(∞) (2) f(0_+)-f(∞)=K (3)     

二阶奇异周期边值问题正解的存在性和多重性

研究了二阶奇异周期边值问题u（″t）＋a（t）u（t）=f（t,u（t））,t∈[0,ω],u（0）=u（ω）,u（′0）=u′（ω）正解的存在性,当允许f（t,u）在u=0和u=c（c〉0）同时奇异时,用锥映射的Krasnoselsk ii不动点定理获得了其正解的存在性和多重性结果.     

判别函数图象对称性的一组命题及应用

常用于判别函数图象对称性的命题可归纳如下:命题1　若函数y=f(x)满足f(a x)=f(b-x),则y=f(x)的图象关于直线x=a b2对称.证　在y=f(x)图象上取A(a x0,y0),B(b-x0,y0),则AB中点为(a b2,y0),且对任一x0都成立,由x0任意性可知f(x)的图象关于直线x=a b2对称.推论1　若函数y=f(x)满足f(a ωx)=f(b-ωx),则y=f(ωx)关于x=12ω(a b)对称,即y=f(x)关于x=a b2对称.证　设ωx=t,则f(a t)=f(b-t),从而函数y=f(t)关于t=a b2对称,即y=f(ωx)关于直线x=a b2ω对称,或y=f(x)关于直线x=a b2对称.命题2　函数y=f(x)若满足f(a x)=-f(b-x),则y=f(x)的图象关于…     

关于L^2情形的Fourier—Laplace级数与连续模的一个不等式

研究L^2情形的Fourier-Laplace级数与连续模的关系，得到：当f∈L^2（Ωn),m∈N时有∞↑∑j=1↓m√logj||Yj(f)||2^2≤Cn,r∫0^1ωr(f1t)2^2/t(log1/t)^1-1/mdt。     

一类带有非线性阻尼项的二阶周期系统的Lagrangian稳定性

用KAM迭代方法研究了下列二阶微分方程:(φP(x′))′+F(x,x′,f)+ωpφP(x′)+α∣x∣ ′+e(x,t)=0,其中,φP(s)=∣s ∣P-2s,p＞l,α＞0,ω＞0为正常数,f满足-1＜ω＜p +2.当F(x,x ′,t)与e(x,t)的导数满足一定条件时,利用可逆映射的小扭转定理得到拟周期解的...     

Bloch型空间到Zygmund型空间的广义Cesàro算子和复合算子的积

ω和μ是[0,1)上的正规函数,g是单位球(B)n上的全纯函数,φ是(B)n上的全纯自映射,由g和φ诱导的算子TgCφ:Bω(Bω,0)→Zμ(Zμ,0)定义为:TgCφf(z)=∫10f(φ(tz))(R)g(tz)dt/t,z∈(B)n,f∈Bω(Bω,0).给出了该算子从Bloch型空间到Zygmund型空间有界和紧的充要条件.     

关于多线性算子的加权模不等式

本文给出了加权模不等式 integral from -∞ to +∞ |M_*~(k)(f)|~pω≤c integral from -∞ to +∞ |f|~pω成立的充分必要条件,其中M_*~(k)(f)=sup|H_t(aH_t(a…aH_t(f)…)|(t＜0),a∈L~∞,H_t 是 smoothly truncated Hilbert 变换。从而推广了 R.Coifman 等人已有的结果。     

Bernstein-Kantorovich 算子同时逼近的等价定理

借助于Ditzian-Torik光滑模ω^rλψ(f,t)(0≤λ≤1），讨论了Bernstein-Kantorovich算子线性组合同时逼近问题，给出了该算子同时逼近的等价定理，拓广了文献[3,5]的主要结果。     

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.