Fock-Sobolev空间上有界、紧与S_p-类算子

本文研究Fock-Sobolev空间上稠密定义算子,将这些算子统一表示成积分算子,利用积分算子的方法得到了它们的一个充分条件,并构造反例说此充分条件是非必要的,还得到这些算子为紧算子的两个充分条件.最后构造符号函数在复平面上每一点处本性无界的紧和Sp-类(0p∞)Toeplitz算子.     

D2-C76旋光度的理论研究

应用电磁场与分子相互作用理论,给出了分子旋光度的计算公式.对D₂-C₇₆的旋光度进行了估算,得到它的旋光度约为1°/cm.     

秩函数与K0群的状态空间

给出了局部秩与稳定自由秩的表达式,得到了一类VN正则环的元素特征.利用K₀群的状态空间,给出了K0R有关性态的本质刻画.     

Banach 空间上算子的几种不可约性

本文根据Cowen-Douglas 算子的定义引入两类与强不可约算子有紧密联系的算子类— B_n 算子与B 算子. 说明了在可分Banach 空间上存在B_n 算子与B 算子. 文章详细讨论了几种具有不可约性的算子类之间的关系并得到了一个关系图. 本文还给出这些算子类的一些性质, 包括算子的(拟) 相似不变性等.     

极大多线性奇异积分算子的一些点态估计

建立了联系极大多线性奇异积分算子与某些古典极大算子的两个点态估计, 这些点态估计隐含着极大多线性奇异积分算子的重排估计和BLO(Rⁿ)估计.     

Y-TZP及Y-TZP/Al2O3陶瓷的微波加热及微波烧结特性

用矩形单模TE_10n(n=3,5)微波腔体成功地烧结得到了致密的Y-TZP陶瓷及Y-TZP/Al₂O₃复相陶瓷材料.材料的微波加热特性与其组分有关.Y-TZP含量高有利于提高样品的加热速率并降低加热所需时间.试样加热至600—800℃之后,需随时调整输入功率、短路活塞位置及可调偶合窗开启尺寸,以保持腔体谐振和最佳偶合状态,从而保持一定的升温速度和达到稳定的最终烧结温度.纯Y-TZP及含20Vol％Al₂O₃的Y-TZP/Al₂O₃陶瓷材料均可微波烧结至相对密度98％以上,而晶粒尺寸则分别不大于0.4和1.0μm.实验还发现,温度过高时,试样中心由于达到高于其表面的温度而发生过烧现象.     

广义分数次积分算子在齐次加权Morrey-Herz空间上的有界性

本文研究了广义分数次积分算子在齐次加权Morrey-Herz空间上的有界性.利用对函数进行环形分解技术和算子截断的方法,获得了广义分数次积分算子L~(-β/2)(f)从MK_(p,q1)~(α,λ)(ω1,ω_2~(q1))空间到MK_(p,q2)~(α,λ)(ω_1,ω_2~(q2))空间是有界的,从而将分数次积分算子在齐次加权Morrey-Herz空间上的有界性推广到广义分数次积分算子.     

Bi2Sr2Ca1-xYxCu2O8+y的晶体结构、电子结构和超导电性

本文研究了Y替代Ca对Bi₂Sr₂Ca_1-xY_xCu₂O_8+y,超导体晶体结构和电子状态的影响,发现:Y替代Ca后至少使得Bi-O双层中所夹的一层额外的氧原子发生了变化,沿b轴方向的无公度超格子的调制周期从4.7b连续减小到大约为4.0b;并发现当Y完全替代Ca时,则同时存在大约为4b和8b的调制周期.用XPS进一步研究其电子状态变化的结果表明,超导电性的变化不是由于晶体结构的微小变化引起的,而主要是由CuO₂层中O2p轨道空穴的逐步填充所致.结果明确表明,对于该替代体系依然是当Cu离子3d轨道存在一个空穴时(3d⁹态)对应于强关联的反铁磁绝缘体,而当CuO₂层中氧离子2p轨道存在额外的空穴时(即3d⁹L态)对应于超导体.     

一类多线性齐性算子的Hardy空间估计 *

证明了一类带齐性核的奇异积分算子的多线性算子是乘积空间L^p1×L^p2 ×…×L^pK(Rⁿ)到Hardy空间H^r(Rⁿ)和弱Hardy空间H^{r ,∞}(Rⁿ)的有界算子 .作为应用 ,获得了一类带齐性核的奇异积分算子交换子的L^p(Rⁿ)有界性 .     

加权Herz型的Hardy空间及其应用

引进加权Herz型的Hardy空间,建立了它的原子分解理论,作为这个理论的应用,建立了次线性算子在这些空间上的有界性定理和线性算子在这些空间上的插值定理.     

带非卷积核的分数次振荡积分算子及其交换子的加权有界性质——献给陆善镇教授75华诞

振荡积分算子的有界性质是调和分析研究的中心内容之一.本文建立一类由Ricci和Stein定义的带非卷积核的分数次振荡积分算子在加权Lebesgue空间中的有界性质.特别地,结合复分析和数学归纳等方法得到该类算子和有界平均振幅（BMO）函数生成交换子的加权有界性质.     

Rough oscillatory singular integral operators of nonconvolution type

In this paper, we study a classes of oscillatory singular integral operators of nonconvolution type with phases more general than polynomials. We prove that such operators are bounded on Lp provided their kernels satisfy a very weak condition. In addition, we also study the related truncated oscillatory singular integral operators. Moreover, we present a class of unbounded oscillatory singular integral operators.     

多线性分数次积分算子一般框架下的交换子的有界性——献给陆善镇教授75华诞

对任意给定的正整数m,Z^＋×{1,...,m}的任意一个有限子集S,定义一般化的多线性分数次积分算子的交换子Iα,→b,S（f）（x）=∫（Rn）^m ∏（i,j）∈S（bi（x）-bi（yj））/（｜x-y1｜＋…＋｜x-ym｜）^mn-α∏（j=1→m）fj（yj）d→y,其中d→y=dy1…dym.此框架下的交换子包含了以往研究的各类分数次积分算子的交换子,并蕴含了多线性背景下新的交换子形式.在上述非常一般框架下,本文给出带多重A→p,q权的多线性分数次积分算子的交换子Iα,→b,S（→f）的加权强型（L^p1（ω1）×···×L^pm（ωm）,L^q（ν→ωq））估计和加权弱型端点估计.本文还得到更一般核条件下的上述结果.     

Estimates on level set integral operators in dimension two

Both oscillatory integral operators and level set operators appear naturally in the study of properties of degenerate Fourier integral operators (such as generalized Randon transforms). The properties of oscillatory integral operators have a longer history and are better understood. On the other hand, level set operators, while sharing many common characteristics with oscillatory integral operators, are easier to handle. We study L²-estimates on level set operators in dimension two and compare them with what is known about oscillatory integral operators. The cases include operators with non-degenerate phase functions and the level set version of Melrose-Taylor transform (as an example of a degenerate phase function). The estimates are formulated in terms of the Newton polyhedra and type conditions.     

On the rate of approximation by q modified Beta operators

In the present paper we propose the q analogue of the modified Beta operators. We apply q-derivatives to obtain the central moments of the discrete q-Beta operators. A direct result in terms of modulus of continuity for the q operators is also established. We have also used the properties of q integral to establish the recurrence formula for the moments of q analogue of the modified Beta operators. We also establish an asymptotic formula. In the end we have also present the modification of such q operators so as to have better estimate.     

Estimates for oscillatory strongly singular integral operators

In this paper we consider oscillatory integral operators with strong singularities on . We obtain sharp decay estimates for L² operator norm. We also obtain H^p estimates for difference of oscillatory strongly singular integral operators and strongly singular integral operators, which gives L^p mapping properties of oscillatory strongly singular integral operators.     

On α-convex operators

In this paper, the existence and uniqueness of positive fixed points for a class of convex operators is obtained by means of the properties of cone, concave operators and the monotonicity of set-valued maps. In the end, we give a simple application to certain integral equations.     

Area integral functions for sectorial operators on L spaces

Area integral functions are introduced for sectorial operators on L^p-spaces. We establish the equivalence between the square and area integral functions for sectorial operators on L^p spaces. This follows that the results of Cowling, Doust, McIntosh, Yagi, and Le Merdy on H^infin functional calculus of sectorial operators on L^p-spaces hold true when the square functions are replaced by the area integral functions.     

An extension based on qR-integral for a sequence of operators

The paper deals with a sequence of linear positive operators introduced via q-Calculus. We give a generalization in Kantorovich sense of its involving qR-integrals. Both for discrete operators and for integral operators we study the error of approximation for bounded functions and for functions having a polynomial growth. The main tools consist of the K-functional in Peetre sense and different moduli of smoothness.     

Estimates for vector-valued commutators on weighted Morrey space and applications

In this paper, we introduce weighted vector-valued Morrey spaces and obtain some estimates for vector-valued commutators on these spaces. Applications to Calderón-Zygmund singular integral operators, oscillatory singular integral operators and parabolic difference equations are considered.