In this paper, we investigate the bounds of the coefficients of several classes of bi-univalent functions. The results presented in this paper improve of generalize the recent works of other authors.
In this paper we consider the class of Bazilevic functions for bi-univalent functions. For this we will estimate the coefficients a2 and a3 using Caratheodory func- tions and the method of differential subordination.
In this paper, we introduce several new subclasses of the function class Σ of bi-univalent functions analytic in the open unit disc defined by convolution.Furthermore, we investigate the bounds of the coefficients |a...In this paper, we introduce several new subclasses of the function class Σ of bi-univalent functions analytic in the open unit disc defined by convolution.Furthermore, we investigate the bounds of the coefficients |a2| and |a3| for functions in these new subclasses. The results presented in this paper improve or generalize the recent works of other authors.展开更多
In this paper, we have investigated second Hankel determinants and FeketeSzeg? inequalities for some subclasses of Bi-univalent functions with respect to symmetric and Conjugate points which are subordinate to a shell...In this paper, we have investigated second Hankel determinants and FeketeSzeg? inequalities for some subclasses of Bi-univalent functions with respect to symmetric and Conjugate points which are subordinate to a shell shaped region in the open unit disc ?.展开更多
Motivated and stimulated especially by the work of Xu et al. [1], in this paper, we introduce and discuss an interesting subclass of analytic and bi-univalent functions defined in the open unit disc U. Further, we fin...Motivated and stimulated especially by the work of Xu et al. [1], in this paper, we introduce and discuss an interesting subclass of analytic and bi-univalent functions defined in the open unit disc U. Further, we find estimates on the coefficients and for functions in this subclass. Many relevant connections with known or new results are pointed out.展开更多
In this paper, we investigate the coefficient estimates of a class of m-fold bi-univalent function de?ned by subordination. The results presented in this paper improve or generalize the recent works of other authors.
In this paper, we introduce a new subclass of bi-univalent functions defined by quasi-subordination and Hohlov operator and obtain the coefficient estimates and Fekete-Szego inequality for function in this new subclas...In this paper, we introduce a new subclass of bi-univalent functions defined by quasi-subordination and Hohlov operator and obtain the coefficient estimates and Fekete-Szego inequality for function in this new subclass. The results presented in this paper improve or generalize the recent works of other authors.展开更多
In this paper, we introduce and investigate a new subclass of the function class ∑. of bi-univalent functions of the Mocanu-convex type defined in the open unit disk, satisfy Ma and Minda subordination conditions. Fu...In this paper, we introduce and investigate a new subclass of the function class ∑. of bi-univalent functions of the Mocanu-convex type defined in the open unit disk, satisfy Ma and Minda subordination conditions. Furthermore, we find estimates on the Taylor-Maclaurin coefficients ｜a2｜ and ｜a3｜ for functions in the new subclass introduced here. Further Application of Hohlov operator to this class is obtained. Several （known or new） consequences of the results are also pointed out.展开更多
Let A be the space of functions analytic in the unit disk D = {z：｜z｜ 〈 1}.Let U denote the set of all functions f ∈ A satisfying the conditions f（0） = f＇（0）-1 = 0 and｜f＇（z）（z/f（z））2-1｜〈1（｜z｜〈1...Let A be the space of functions analytic in the unit disk D = {z：｜z｜ 〈 1}.Let U denote the set of all functions f ∈ A satisfying the conditions f（0） = f＇（0）-1 = 0 and｜f＇（z）（z/f（z））2-1｜〈1（｜z｜〈1）.Also,let Ω denote the set of all functions f ∈ A satisfying the conditions f（0） = f＇（0）-1 = 0and｜zf＇（z）-f（z）｜〈1/2（｜z｜〈1）.In this article,we discuss the properties of U and Ω.展开更多
Let A denote the family of all analytic functions f(z) in the unit disk D={z ∈C:|z|<1}, normalized by the conditions f(0) = 0 and f'(0) = 1. Let U denote the set of all functions f ∈ A satisfying the conditio...Let A denote the family of all analytic functions f(z) in the unit disk D={z ∈C:|z|<1}, normalized by the conditions f(0) = 0 and f'(0) = 1. Let U denote the set of all functions f ∈ A satisfying the condition |(z/f(z))^2f'(z)-1|<1 for z∈D.Let Ω be the class of all f∈A for which |zf'(z)-f(z)|<1/2, z∈D.In this paper, the relations between the two classes are discussed. Furthermore, some new results on the class Ω are obtained.展开更多
In this paper,some new criteria for univalence of analytic functions defined in the unit disk in terms of two parameters are presented.Moreover,the related result of Aharonov and Elias(Aharonov D,Elias U.Univalence cr...In this paper,some new criteria for univalence of analytic functions defined in the unit disk in terms of two parameters are presented.Moreover,the related result of Aharonov and Elias(Aharonov D,Elias U.Univalence criteria depending on parameters.Anal.Math.Phys.,2014,4(1-2):23–34)is generalized.展开更多
A new characterization of univalent Bloch functions is given by investigating the growth order of an essentially increasing function. Our contribution can be considered as a slight improvement of the well-known Pommer...A new characterization of univalent Bloch functions is given by investigating the growth order of an essentially increasing function. Our contribution can be considered as a slight improvement of the well-known Pommerenke's result and its all generalizations, and the proof presented in this paper is independently developed.展开更多
By employing the Srivastava-Owa fractional operators, we consider a class of fractional differential equation in the unit disk. The existence of the univalent solution is founded by using the Schauder fixed point theo...By employing the Srivastava-Owa fractional operators, we consider a class of fractional differential equation in the unit disk. The existence of the univalent solution is founded by using the Schauder fixed point theorem while the uniqueness is obtained by using the Banach fixed point theorem. Moreover, the integral mean of these solutions is studied by applying the concept of the subordination.展开更多
In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,...In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open harmonic.Finally,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors.展开更多
We obtain some convergence properties concerning Faber polynomials and apply them to studying univalent functions with quasiconformal extensions. In particular, by introducing an operator on the usual l2 space, we obt...We obtain some convergence properties concerning Faber polynomials and apply them to studying univalent functions with quasiconformal extensions. In particular, by introducing an operator on the usual l2 space, we obtain some new characterizations of quasiconformal extendablity and asymptotic conformality for univalent functions.展开更多
The relation between Diff（S^1）/S^1 and the space of univalent analytic functions on the disk is elucidated and shown to provide upper bounds for the volumes of exhaustive approximations to an analytic submanifold of...The relation between Diff（S^1）/S^1 and the space of univalent analytic functions on the disk is elucidated and shown to provide upper bounds for the volumes of exhaustive approximations to an analytic submanifold of an infinite-dimensional space. The maximum magnitudes of the coefficients in the series expansions of univalent superanalytic functions on the superdisk are inferred.展开更多
The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the p...The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the precise values of Bloch constants for certain log-p-harmonic mappings.These results improve upon the corresponding results given in Bai et al.(Complex Anal.Oper.Theory,13(2):321-340,2019).展开更多
The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz^n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any compl...The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz^n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any complex parameter u are obtained by using the fundamental inequalities of analytic functions and analytical techniques and the applications of the inequality of functions defined with Hadaniard product are proved.展开更多
Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation.Here,univalent copper ...Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation.Here,univalent copper species were modified on ZnIn_(2)S_(4)photocatalyst via an in-situ photodeposition method,exhibiting a much higher H2evolution rate of 41.10±3.43 mmol g^(-1)h^(-1)and an impressive apparent quantum efficiency(AQE)of 20.81%at 420±15 nm.Our characterizations indicate that the surface modification by copper species can broaden light utilization as well as promote charge separation and transportation.Besides,the density functional theory(DFT)results further exhibit that the energy levels(LUMO and HOMO)for copper-surface modified ZnIn_(2)S_(4)present spatial separation,locating on the Zn-S and In-S layers,respectively,which can suppress the recombination of electron and hole and thus achieves higher photocatalytic H2evolution efficiency.展开更多
基金supported by NSFC(11071058)Educational Commission of Hubei Province of China(D2011006)
文摘In this paper, we investigate the bounds of the coefficients of several classes of bi-univalent functions. The results presented in this paper improve of generalize the recent works of other authors.
文摘In this paper we consider the class of Bazilevic functions for bi-univalent functions. For this we will estimate the coefficients a2 and a3 using Caratheodory func- tions and the method of differential subordination.
基金The NSF(KJ2015A372) of Anhui Provincial Department of Education
文摘In this paper, we introduce several new subclasses of the function class Σ of bi-univalent functions analytic in the open unit disc defined by convolution.Furthermore, we investigate the bounds of the coefficients |a2| and |a3| for functions in these new subclasses. The results presented in this paper improve or generalize the recent works of other authors.
文摘In this paper, we have investigated second Hankel determinants and FeketeSzeg? inequalities for some subclasses of Bi-univalent functions with respect to symmetric and Conjugate points which are subordinate to a shell shaped region in the open unit disc ?.
文摘Motivated and stimulated especially by the work of Xu et al. [1], in this paper, we introduce and discuss an interesting subclass of analytic and bi-univalent functions defined in the open unit disc U. Further, we find estimates on the coefficients and for functions in this subclass. Many relevant connections with known or new results are pointed out.
基金The NSF(KJ2018A0839,KJ2018A0833) of Anhui Provincial Department of Education
文摘In this paper, we investigate the coefficient estimates of a class of m-fold bi-univalent function de?ned by subordination. The results presented in this paper improve or generalize the recent works of other authors.
基金The NSF(11561001)of Chinathe NSF(2014MS0101)of Inner Mongolia Province+1 种基金the Higher School Foundation(NJZY19211)of Inner Mongolia of Chinathe NSF(KJ2018A0839,KJ2018A0833)of Anhui Provincial Department of Education
文摘In this paper, we introduce a new subclass of bi-univalent functions defined by quasi-subordination and Hohlov operator and obtain the coefficient estimates and Fekete-Szego inequality for function in this new subclass. The results presented in this paper improve or generalize the recent works of other authors.
文摘In this paper, we introduce and investigate a new subclass of the function class ∑. of bi-univalent functions of the Mocanu-convex type defined in the open unit disk, satisfy Ma and Minda subordination conditions. Furthermore, we find estimates on the Taylor-Maclaurin coefficients ｜a2｜ and ｜a3｜ for functions in the new subclass introduced here. Further Application of Hohlov operator to this class is obtained. Several （known or new） consequences of the results are also pointed out.
基金Supported by the Key Laboratory of Applied Mathematics in Hubei Province,China
文摘Let A be the space of functions analytic in the unit disk D = {z：｜z｜ 〈 1}.Let U denote the set of all functions f ∈ A satisfying the conditions f（0） = f＇（0）-1 = 0 and｜f＇（z）（z/f（z））2-1｜〈1（｜z｜〈1）.Also,let Ω denote the set of all functions f ∈ A satisfying the conditions f（0） = f＇（0）-1 = 0and｜zf＇（z）-f（z）｜〈1/2（｜z｜〈1）.In this article,we discuss the properties of U and Ω.
基金supported by the Key Laboratory of Applied Mathematics in Hubei Province,Chinasupported by MNZZS(ON174017,Serbia)
文摘Let A denote the family of all analytic functions f(z) in the unit disk D={z ∈C:|z|<1}, normalized by the conditions f(0) = 0 and f'(0) = 1. Let U denote the set of all functions f ∈ A satisfying the condition |(z/f(z))^2f'(z)-1|<1 for z∈D.Let Ω be the class of all f∈A for which |zf'(z)-f(z)|<1/2, z∈D.In this paper, the relations between the two classes are discussed. Furthermore, some new results on the class Ω are obtained.
基金The NSF(11501001)of Chinathe NSF(1908085MA18)of Anhui Provincethe Foundation(Y01002428)of Anhui University
文摘In this paper,some new criteria for univalence of analytic functions defined in the unit disk in terms of two parameters are presented.Moreover,the related result of Aharonov and Elias(Aharonov D,Elias U.Univalence criteria depending on parameters.Anal.Math.Phys.,2014,4(1-2):23–34)is generalized.
基金This research was supported in part by a grant from the Vaisala Fund, Finland
文摘A new characterization of univalent Bloch functions is given by investigating the growth order of an essentially increasing function. Our contribution can be considered as a slight improvement of the well-known Pommerenke's result and its all generalizations, and the proof presented in this paper is independently developed.
文摘By employing the Srivastava-Owa fractional operators, we consider a class of fractional differential equation in the unit disk. The existence of the univalent solution is founded by using the Schauder fixed point theorem while the uniqueness is obtained by using the Banach fixed point theorem. Moreover, the integral mean of these solutions is studied by applying the concept of the subordination.
基金supported by the Natural Science Foundation of Guangdong Province(2021A1515010058)。
文摘In this paper,we first obtain the precise values of the univalent radius and the Bloch constant for harmonic mappings of the formL(f)=zfz-zfz,where f represents normalized harmonic mappings with bounded dilation.Then,using these results,we present better estimations for the Bloch constants of certain harmonic mappings L(f),where f is a K-quasiregular harmonic or open harmonic.Finally,we establish three versions of BlochLandau type theorem for biharmonic mappings of the form L(f).These results are sharp in some given cases and improve the related results of earlier authors.
基金supported by the Program for New Century Excellent Talents in University (Grant No. 06-0504)National Natural Science Foundation of China (Grant No. 10771153)
文摘We obtain some convergence properties concerning Faber polynomials and apply them to studying univalent functions with quasiconformal extensions. In particular, by introducing an operator on the usual l2 space, we obtain some new characterizations of quasiconformal extendablity and asymptotic conformality for univalent functions.
基金Project supported by the National Natural Science Foundation of China.
文摘We make improvements to some of the constants concerned with univalent functions with quasiconformal extensions that have appeared in the literature.
文摘The relation between Diff（S^1）/S^1 and the space of univalent analytic functions on the disk is elucidated and shown to provide upper bounds for the volumes of exhaustive approximations to an analytic submanifold of an infinite-dimensional space. The maximum magnitudes of the coefficients in the series expansions of univalent superanalytic functions on the superdisk are inferred.
基金supported by Guangdong Natural Science Foundation(2018A030313508)。
文摘The aim of this article is twofold.One aim is to establish the precise forms of Landau-Bloch type theorems for certain polyharmonic mappings in the unit disk by applying a geometric method.The other is to obtain the precise values of Bloch constants for certain log-p-harmonic mappings.These results improve upon the corresponding results given in Bai et al.(Complex Anal.Oper.Theory,13(2):321-340,2019).
基金Supported by the Natural Science Foundation of Department of Education of Anhui Province（KJ2015A372）
文摘The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz^n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any complex parameter u are obtained by using the fundamental inequalities of analytic functions and analytical techniques and the applications of the inequality of functions defined with Hadaniard product are proved.
基金financially supported by the National Natural Science Funds for Distinguished Young Scholars(51725201)the International(Regional)Cooperation and Exchange Projects of the National Natural Science Foundation of China(51920105003)+4 种基金the Innovation Program of Shanghai Municipal Education Commission(E00014)the Science and Technology Commission of Shanghai Municipality(21DZ1207101)the National Natural Science Foundation of China(21902048)the Shanghai Engineering Research Center of Hierarchical Nanomaterials(18DZ2252400)Additional support was provided by the Feringa Nobel Prize Scientist Joint Research Center。
文摘Surface modification by metal ion has been considered a promising strategy to enhance the photocatalytic activity by extending optical response and improving charge separation and transportation.Here,univalent copper species were modified on ZnIn_(2)S_(4)photocatalyst via an in-situ photodeposition method,exhibiting a much higher H2evolution rate of 41.10±3.43 mmol g^(-1)h^(-1)and an impressive apparent quantum efficiency(AQE)of 20.81%at 420±15 nm.Our characterizations indicate that the surface modification by copper species can broaden light utilization as well as promote charge separation and transportation.Besides,the density functional theory(DFT)results further exhibit that the energy levels(LUMO and HOMO)for copper-surface modified ZnIn_(2)S_(4)present spatial separation,locating on the Zn-S and In-S layers,respectively,which can suppress the recombination of electron and hole and thus achieves higher photocatalytic H2evolution efficiency.
