We find the necessary and sufficient conditions on a coproduct of connected acts over a semigroup to be strongly hopfian. From this, we deduce the conditions of the strong hopfness for unitary acts over groups. Moreov...We find the necessary and sufficient conditions on a coproduct of connected acts over a semigroup to be strongly hopfian. From this, we deduce the conditions of the strong hopfness for unitary acts over groups. Moreover, we prove that a finite coproduct of strongly hopfian acts over an arbitrary semigroup is strongly hopfian.展开更多
Let G be a finite group of order n. The strong power graph of G is the undirected graph whose vertex set is G and two distinct vertices x and y are adjacent if x^n1 = y^n2 for some positive integers n1,n2 < n. In t...Let G be a finite group of order n. The strong power graph of G is the undirected graph whose vertex set is G and two distinct vertices x and y are adjacent if x^n1 = y^n2 for some positive integers n1,n2 < n. In this paper, we give the characteristic polynomials of the distance and adjacency matrix of the strong power graph of G, and compute its distance and adjacency spectrum.展开更多
The temporal and spatial distributions of all the 259 M≥6 earthquakes of eastern Chinese mainland (λ≥108° E) and its adjacent area and all the 153 M≥7 earthquakes of western Chinese mainland (λ<108°E...The temporal and spatial distributions of all the 259 M≥6 earthquakes of eastern Chinese mainland (λ≥108° E) and its adjacent area and all the 153 M≥7 earthquakes of western Chinese mainland (λ<108°E) and its adjacent area up to 1991 were analyzed systematically.These earthquakes are called as strong earthquakes and those of the east before and after 1600,and those of the west before and after 1900, are called respectively as former ones and latter ones.Most of these events were divided into 45 sets of which the each relatively concentrated in both time and space and took the form of group.In the grouping form,the probability of occurrence of a strong earthquake higher than the average appeared simultaneously in time and space.The grouping occurrences of the strong earthquakes of Chinese mainland has been determined as a fundamental feature of the seismicity.展开更多
Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of pr...Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of precursory groups (ID) and the values of short-term and impending anomaly in near-source area (NS). Using these methods, we calculate the observational data of deformation, underground fluid and hydrochemical constituents obtained from different seismic stations in the Sichuan-Yunnan region and conclude that the synthetic precursory anomalies of a single strong earthquake with M S6.0 differ greatly from those of the grouped strong earthquakes, for the anomalous information of precursory groups are more abundant. The three methods of extracting the synthetic precursory anomaly and the related numerical results can be applied into the practice of prediction to the grouped strong earthquakes in the Sichuan-Yunnan region. Inhomogeneous degree (ID) of synthetic precursory anomaly can be identified automatically because it takes the threshold of distributive characteristics of the anomalies of precursory group as its criterion for anomaly.展开更多
When R satisfies (strong unit) 1-stable range and M is a R-R-bimodule, the authors calculate that K_1(R(?) M)≌U(R(?) M)/L(R(?) M). As applications, the authors also calculate some Whitehead groups for exchange rings ...When R satisfies (strong unit) 1-stable range and M is a R-R-bimodule, the authors calculate that K_1(R(?) M)≌U(R(?) M)/L(R(?) M). As applications, the authors also calculate some Whitehead groups for exchange rings with artinian primitive factors.展开更多
The goal of this paper is to confirm that the unitary group U(H) on an infinite dimensional complex Hilbert space is a topological group in its strong topology, and to emphasize the importance of this property for app...The goal of this paper is to confirm that the unitary group U(H) on an infinite dimensional complex Hilbert space is a topological group in its strong topology, and to emphasize the importance of this property for applications in topology. In addition, it is shown that U(H) in its strong topology is metrizable and contractible if H is separable. As an application Hilbert bundles are classified by homotopy.展开更多
From November 1,2013, Translational Lung Cancer Research （TLCR） is officially endorsed by the Spanish Lung Cancer Group （Figure 1）. This is a meaningful milestone for TLCR as an acknowledgment of its expansion and...From November 1,2013, Translational Lung Cancer Research （TLCR） is officially endorsed by the Spanish Lung Cancer Group （Figure 1）. This is a meaningful milestone for TLCR as an acknowledgment of its expansion and dedication to lung cancer research and will tremendously advance its continued exploration in the field.展开更多
Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]...Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.展开更多
Strong electron-donating dialkylamino groups were incoporated onto the phthalocyanine ligand in bis(phthalocyaninato)rare earth complexes for the first time to investigate their effects on the spectroscopic properties...Strong electron-donating dialkylamino groups were incoporated onto the phthalocyanine ligand in bis(phthalocyaninato)rare earth complexes for the first time to investigate their effects on the spectroscopic properties,electrochemistry,and electronic structure.展开更多
We propose a new heterogeneous parallel strategy for the density matrix renormalization group(DMRG)method in the hybrid architecture with both central processing unit(CPU)and graphics processing unit(GPU).Focusing on ...We propose a new heterogeneous parallel strategy for the density matrix renormalization group(DMRG)method in the hybrid architecture with both central processing unit(CPU)and graphics processing unit(GPU).Focusing on the two most time-consuming sections in the finite DMRG sweeps,i.e.,the diagonalization of superblock and the truncation of subblock,we optimize our previous hybrid algorithm to achieve better performance.For the former,we adopt OpenMP application programming interface on CPU and use our own subroutines with higher bandwidth on GPU.For the later,we use GPU to accelerate matrix and vector operations involving the reduced density matrix.Applying the parallel scheme to the Hubbard model with next-nearest hopping on the 4-leg ladder,we compute the ground state of the system and obtain the charge stripe pattern which is usually observed in high temperature superconductors.Based on simulations with different numbers of DMRG kept states,we show significant performance improvement and computational time reduction with the optimized parallel algorithm.Our hybrid parallel strategy with superiority in solving the ground state of quasi-two dimensional lattices is also expected to be useful for other DMRG applications with large numbers of kept states,e.g.,the time dependent DMRG algorithms.展开更多
We propose an improved real-space parallel strategy for the density matrix renormalization group(DMRG)method,where boundaries of separate regions are adaptively distributed during DMRG sweeps.Our scheme greatly improv...We propose an improved real-space parallel strategy for the density matrix renormalization group(DMRG)method,where boundaries of separate regions are adaptively distributed during DMRG sweeps.Our scheme greatly improves the parallel efficiency with shorter waiting time between two adjacent tasks,compared with the original real-space parallel DMRG with fixed boundaries.We implement our new strategy based on the message passing interface(MPI),and dynamically control the number of kept states according to the truncation error in each DMRG step.We study the performance of the new parallel strategy by calculating the ground state of a spin-cluster chain and a quantum chemical Hamiltonian of the water molecule.The maximum parallel efficiencies for these two models are 91%and 76%in 4 nodes,which are much higher than the real-space parallel DMRG with fixed boundaries.展开更多
In this paper, we discussed w-extension of bicyclic semigroups. Two types of this extension are proposed. In §2 we discussed strong semilattice extension and the structure of the extension is well presented. In &...In this paper, we discussed w-extension of bicyclic semigroups. Two types of this extension are proposed. In §2 we discussed strong semilattice extension and the structure of the extension is well presented. In §3 we discussed another order extension. We proved that congruence lattice of this extension semigroups is union set of two sublattice. One is the group congruence semilattice, the other is the pure idempotent congruence semilattice.展开更多
We study a new class of group inverses determined by right c-regular elements.The new concept of right c-group inverses is introduced and studied.It is shown that every right c-group invertible element is group invert...We study a new class of group inverses determined by right c-regular elements.The new concept of right c-group inverses is introduced and studied.It is shown that every right c-group invertible element is group invertible,and an example is given to show that group invertible elements need not be right c-group invertible.The conditions that right c-group invertible elements are precisely group invertible elements are investigated.We also study the strongly clean decompositions of right c-group invertible elements.As applications,we give some new characterizations of abelian rings and directly finite rings from the point of view of right c-groupinverses.展开更多
文摘We find the necessary and sufficient conditions on a coproduct of connected acts over a semigroup to be strongly hopfian. From this, we deduce the conditions of the strong hopfness for unitary acts over groups. Moreover, we prove that a finite coproduct of strongly hopfian acts over an arbitrary semigroup is strongly hopfian.
基金Supported by the National Natural Science Foundation of China(Grant No.11801441)the Scientific Research Program Funded by Shaanxi Provincial Education Department(Program No.18JK0623)the Natural Science Foundation of Shaanxi Province(Grant No.2019JQ-056)
文摘Let G be a finite group of order n. The strong power graph of G is the undirected graph whose vertex set is G and two distinct vertices x and y are adjacent if x^n1 = y^n2 for some positive integers n1,n2 < n. In this paper, we give the characteristic polynomials of the distance and adjacency matrix of the strong power graph of G, and compute its distance and adjacency spectrum.
文摘The temporal and spatial distributions of all the 259 M≥6 earthquakes of eastern Chinese mainland (λ≥108° E) and its adjacent area and all the 153 M≥7 earthquakes of western Chinese mainland (λ<108°E) and its adjacent area up to 1991 were analyzed systematically.These earthquakes are called as strong earthquakes and those of the east before and after 1600,and those of the west before and after 1900, are called respectively as former ones and latter ones.Most of these events were divided into 45 sets of which the each relatively concentrated in both time and space and took the form of group.In the grouping form,the probability of occurrence of a strong earthquake higher than the average appeared simultaneously in time and space.The grouping occurrences of the strong earthquakes of Chinese mainland has been determined as a fundamental feature of the seismicity.
文摘Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of precursory groups (ID) and the values of short-term and impending anomaly in near-source area (NS). Using these methods, we calculate the observational data of deformation, underground fluid and hydrochemical constituents obtained from different seismic stations in the Sichuan-Yunnan region and conclude that the synthetic precursory anomalies of a single strong earthquake with M S6.0 differ greatly from those of the grouped strong earthquakes, for the anomalous information of precursory groups are more abundant. The three methods of extracting the synthetic precursory anomaly and the related numerical results can be applied into the practice of prediction to the grouped strong earthquakes in the Sichuan-Yunnan region. Inhomogeneous degree (ID) of synthetic precursory anomaly can be identified automatically because it takes the threshold of distributive characteristics of the anomalies of precursory group as its criterion for anomaly.
基金This research is supported by the National Natural Science Foundation of China (19801012)the Ministry of Education of China([2000]65)
文摘When R satisfies (strong unit) 1-stable range and M is a R-R-bimodule, the authors calculate that K_1(R(?) M)≌U(R(?) M)/L(R(?) M). As applications, the authors also calculate some Whitehead groups for exchange rings with artinian primitive factors.
文摘The goal of this paper is to confirm that the unitary group U(H) on an infinite dimensional complex Hilbert space is a topological group in its strong topology, and to emphasize the importance of this property for applications in topology. In addition, it is shown that U(H) in its strong topology is metrizable and contractible if H is separable. As an application Hilbert bundles are classified by homotopy.
文摘From November 1,2013, Translational Lung Cancer Research （TLCR） is officially endorsed by the Spanish Lung Cancer Group （Figure 1）. This is a meaningful milestone for TLCR as an acknowledgment of its expansion and dedication to lung cancer research and will tremendously advance its continued exploration in the field.
基金support of this work by National Natural Science Foundation of China(22075031,51673030,51603017 and 51803011)Jilin Provincial Science&Technology Department(20220201105GX)Chang Bai Mountain Scholars Program of Jilin Province.
文摘Achieving high fouling resistance and permeability using membrane separation technology in water treatment processes remains a challenge.In this work,a novel mixed-matrix membrane(MMM)(poly(arylene ether ketone)[PAEK]-containing carboxyl groups[PAEK-COOH]/UiO-66-NH_(2)@graphene oxide[GO])with superb fouling resistance and high permeability was prepared by the nonsolvent-induced phase separation method,by in-situ growth of UiO-66-NH_(2) on the GO layer,and by preparing hydrophilic PAEK-COOH.On the basis of the structure and performance analysis of the MMM,the maximum water flux reached 591.25 L·m^(-2)·h^(-1) for PAEK-COOH/UiO-66-NH_(2)@GO,whereas the retention rate for bovine serum albumin increased from 85.40%to 94.87%.As the loading gradually increased,the hydrophilicity of the MMMs increased,significantly enhancing their fouling resistance.The strongest anti-fouling ability observed was 94.74%,which was 2.02 times greater than that of the pure membrane.At the same time,the MMMs contained internal amide and hydrogen bonds during the preparation process,forming a cross-linked structure,which further enhanced the mechanical strength and chemical stability.In summary,the MMMs with high retention rate,strong permeability,and anti-fouling ability were successfully prepared.
基金support from the National Key Basic Research Program of China(Grant No.2013CB933402)the Natural Science Foundation of China(No.21290174,21631003,21671017,21301017,and 21401009)the Beijing Municipal Commission of Education,and the University of Science and Technology Beijing is gratefully acknowledged.
文摘Strong electron-donating dialkylamino groups were incoporated onto the phthalocyanine ligand in bis(phthalocyaninato)rare earth complexes for the first time to investigate their effects on the spectroscopic properties,electrochemistry,and electronic structure.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674139,11834005,and 11904145)the Program for Changjiang Scholars and Innovative Research Team in University,China(Grant No.IRT-16R35).
文摘We propose a new heterogeneous parallel strategy for the density matrix renormalization group(DMRG)method in the hybrid architecture with both central processing unit(CPU)and graphics processing unit(GPU).Focusing on the two most time-consuming sections in the finite DMRG sweeps,i.e.,the diagonalization of superblock and the truncation of subblock,we optimize our previous hybrid algorithm to achieve better performance.For the former,we adopt OpenMP application programming interface on CPU and use our own subroutines with higher bandwidth on GPU.For the later,we use GPU to accelerate matrix and vector operations involving the reduced density matrix.Applying the parallel scheme to the Hubbard model with next-nearest hopping on the 4-leg ladder,we compute the ground state of the system and obtain the charge stripe pattern which is usually observed in high temperature superconductors.Based on simulations with different numbers of DMRG kept states,we show significant performance improvement and computational time reduction with the optimized parallel algorithm.Our hybrid parallel strategy with superiority in solving the ground state of quasi-two dimensional lattices is also expected to be useful for other DMRG applications with large numbers of kept states,e.g.,the time dependent DMRG algorithms.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674139,11834005,and 11904145)the Program for Changjiang Scholars and Innovative Research Team in Universities,China(Grant No.IRT-16R35).
文摘We propose an improved real-space parallel strategy for the density matrix renormalization group(DMRG)method,where boundaries of separate regions are adaptively distributed during DMRG sweeps.Our scheme greatly improves the parallel efficiency with shorter waiting time between two adjacent tasks,compared with the original real-space parallel DMRG with fixed boundaries.We implement our new strategy based on the message passing interface(MPI),and dynamically control the number of kept states according to the truncation error in each DMRG step.We study the performance of the new parallel strategy by calculating the ground state of a spin-cluster chain and a quantum chemical Hamiltonian of the water molecule.The maximum parallel efficiencies for these two models are 91%and 76%in 4 nodes,which are much higher than the real-space parallel DMRG with fixed boundaries.
基金Supported by the NNSF of China(6047303060773035)
文摘In this paper, we discussed w-extension of bicyclic semigroups. Two types of this extension are proposed. In §2 we discussed strong semilattice extension and the structure of the extension is well presented. In §3 we discussed another order extension. We proved that congruence lattice of this extension semigroups is union set of two sublattice. One is the group congruence semilattice, the other is the pure idempotent congruence semilattice.
基金Supported by the National Natural Science Foundation of China(Grant No.12161049).
文摘We study a new class of group inverses determined by right c-regular elements.The new concept of right c-group inverses is introduced and studied.It is shown that every right c-group invertible element is group invertible,and an example is given to show that group invertible elements need not be right c-group invertible.The conditions that right c-group invertible elements are precisely group invertible elements are investigated.We also study the strongly clean decompositions of right c-group invertible elements.As applications,we give some new characterizations of abelian rings and directly finite rings from the point of view of right c-groupinverses.
