This note is to investigate the properties of strongly semipotent rings.It is proved that every strongly semipotent ring is a idempotent unit regular ring,i.e.,there exist a non-zero idempotent e and a unit u such tha...This note is to investigate the properties of strongly semipotent rings.It is proved that every strongly semipotent ring is a idempotent unit regular ring,i.e.,there exist a non-zero idempotent e and a unit u such that er=eu for all r∉J(R),where J(R)is the Jacobson radical of ring R.展开更多
Solid strong base catalysts have high potentials in a variety of reactions due to the advantages of negligible corrosion,easy separation,and high efficiency.However,two issues hinder the applications of such catalysts...Solid strong base catalysts have high potentials in a variety of reactions due to the advantages of negligible corrosion,easy separation,and high efficiency.However,two issues hinder the applications of such catalysts seriously,namely aggregation of basic sites and leaching of active species during reactions.The development of solid strong base catalysts with active sites that are highly dispersed and stable remains a pronounced challenge.In this work,we employed a two-step reduction strategy to anchor Na single atoms on nitrogen-doped porous carbon(NPC)support,producing a high-performance solid strongly basic catalyst named as Na1/NPC.The alkali precursor NaNO3was converted to Na_(2)O on NPC at 400℃,in which conventional solid base catalyst Na_(2)O/NPC was generated.Upon heat treatment at 850oC,Na_(2)O was further reduced to Na single atoms anchored on NPC,creating Na1/NPC.Experimental studies and theoretical calculations show that Na is structurally embedded on the support in penta-coordinated configuration(Na-C_(3)N_(2)).The synergistic effect of highly dispersed Na atoms and nitrogen doping results in uncommon catalytic activity and stability.In transesterification between methanol and ethylene carbonate to produce dimethyl carbonate(DMC),the yield of DMC reaches 48.4%over Na1/NPC,corresponding to a turnover frequency(TOF)of 129.4 h^(-1),which is far beyond the conventional counterpart Na_(2)O/NPC(63.3 h^(-1))and various reported solid base catalysts.The catalytic activity of Na1/NPC almost keeps constant during five cycles,while 87%of activity is lost for Na_(2)O/NPC due to the leaching of basic sites.This work might offer new ideas for the development of efficient single-atom solid strong base catalysts with high efficiency.展开更多
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
We investigate the blow-up effect of solutions for a non-homogeneous wave equation u_(tt)−∆u−∆u_(t)=I_(0+)^(α)(|u|^(p))+ω(x),where p>1,0≤α<1 andω(x)with∫_(R)^(N)ω(x)dx>0.By a way of combining the argum...We investigate the blow-up effect of solutions for a non-homogeneous wave equation u_(tt)−∆u−∆u_(t)=I_(0+)^(α)(|u|^(p))+ω(x),where p>1,0≤α<1 andω(x)with∫_(R)^(N)ω(x)dx>0.By a way of combining the argument by contradiction with the test function techniques,we prove that not only any non-trivial solution blows up in finite time under 0<α<1,N≥1 and p>1,but also any non-trivial solution blows up in finite time underα=0,2≤N≤4 and p being the Strauss exponent.展开更多
Multiphase flows widely exist in various scientific and engineering fields,and strongly compressible multiphase flows commonly occur in practical applications,which makes them an important part of computational fluid ...Multiphase flows widely exist in various scientific and engineering fields,and strongly compressible multiphase flows commonly occur in practical applications,which makes them an important part of computational fluid dynamics.In this study,an axisymmetric adaptive multiresolution smooth particle hydrodynamics(SPH)model is proposed to solve various strongly compressible multiphase flow problems.In the present model,the governing equations are discretized in cylindrical polar coordinates,and an improved volume adaptive scheme is developed to better solve the problem of excessive volume change in strongly compressible multiphase flows.On this basis,combined with the adaptive particle refinement technique,an adaptive multiresolution scheme is proposed in this study.In addition,the high-order differential operator and diffusion correction term are utilized to improve the accuracy and stability.The effectiveness of the model is verified by testing four typical strongly compressible multiphase flow problems.By comparing the results of adaptive multiresolution SPH with other numerical results or experimental data,we can conclude that the present SPH method effectively models strongly compressible multiphase flows.展开更多
We investigate the quantum dynamics of the 1D spinless Fermi-Hubbard model with a linear-tilted potential.Surprisingly in a strong resonance regime,we show that the model can be described by the kinetically constraine...We investigate the quantum dynamics of the 1D spinless Fermi-Hubbard model with a linear-tilted potential.Surprisingly in a strong resonance regime,we show that the model can be described by the kinetically constrained effective Hamiltonian,and it can be spontaneously divided into two commuting parts dubbed Hamiltonian dimerization,which are composed of two distinct sets of constrained nearest-neighbor hopping terms:one set acting exclusively on odd bonds and the other on even bonds.Specifically it is shown that each part can be independently mapped onto the well-known PXP model;therefore the dimerized Hamiltonian is equivalent to a two-fold PXP model.As a consequence,we numerically demonstrate this system can host the so-called quantum many-body scars,which present dynamical revivals and ergodicity-breaking behaviors.However,in sharp contrast with traditional quantum many-body scars,here the scarring states in our model driven by different parts of the Hamiltonian will revive in different periods,and those of double parts can display a biperiodic revival pattern,both originating from the Hamiltonian dimerization.Besides,the condition of off-resonance is also discussed,and we show the crossover from quantum many-body scar to ergodicity breaking is diagnosed via level statistics.Our model provides a platform for understanding the interplay of Hilbert space fragmentation and the constrained quantum systems.展开更多
A new type strongly gain coupled (GC) DFB laser and a new type self alignment spot size converter (SA SSC) are proposed and successfully fabricated.The strongly GC DFB laser is monolithically integrated with the ...A new type strongly gain coupled (GC) DFB laser and a new type self alignment spot size converter (SA SSC) are proposed and successfully fabricated.The strongly GC DFB laser is monolithically integrated with the SA SSC with three step epitaxies.A high single mode yield and large side mode suppression ratio is obtained from the strongly GC DFB laser.A near circle far field pattern is obtained by using the SA SSC.展开更多
The authors obtain the growth and covering theorems for strongly starlike mappings of order α on bounded starlike circular domains.This kind of domain discussed is rather general,since the domain must be starlike if ...The authors obtain the growth and covering theorems for strongly starlike mappings of order α on bounded starlike circular domains.This kind of domain discussed is rather general,since the domain must be starlike if exists a normalized biholomorphic starlike mapping on it.展开更多
Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration （NF） membrane was fabricated by simply dipping polysulfone （PSf） ultraf...Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration （NF） membrane was fabricated by simply dipping polysulfone （PSf） ultrafiltration （UF） substrate in dopamine solution. The changes in surface chemical composition and morphology of membranes were determined by Fourier transform infrared spectroscopy （FTIR-ATR）, X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The experimental results indicated that the self-polymerized dopamine formed an ultrathin and defect-free barrier layer on the PSf UF membrane. The surface hydrophilicity of membranes was evaluated through water contact angle measurements. It was found that membrane hydrophilicity was significantly improved after coating a polydopamine （pDA） layer, especially after double coating. The dyes filtration experiments showed that the double-coated membranes were able to reject completely the dyes of brilliant blue, congo red and methyl orange with a pure water flux of 83.7 L/（mE.h） under 0.6 MPa. The zeta potential determination revealed the positively-charged characteristics of PSf/pDA composite membrane in NF process. The salt rejection of the membranes was characterized by 0.01 mmol/L of salts filtration experiment. It was demonstrated that the salts rejections followed the sequence： NaC1 〈 NaaSO4 〈 MgSO4 〈 MgC12 〈 CaCl2, and the rejection to CaC12 reached 68.7%. Moreover, the composite NF membranes showed a good stability in water-phase filtration process.展开更多
The fundamental and second order strongly nonlocal solitons of the nonlocal nonlinear Schrodinger equation for several types of nonlocal responses are calculated by Ritz＇s variational method. For a specific type of n...The fundamental and second order strongly nonlocal solitons of the nonlocal nonlinear Schrodinger equation for several types of nonlocal responses are calculated by Ritz＇s variational method. For a specific type of nonlocal response, the solutions of the strongly nonlocal solitons with the same beam width but different degrees of nonlocality are identical except for an amplitude factor. For a nonlocal case where the nonlocal response function decays in direct proportion to the mth power of the distance near the source point, the power and the phase constant of the strongly nonlocal soliton are in inverse proportion to the （m ＋ 2）th power of its beam width.展开更多
The concept of the strongly π-regular general ring （with or without unity） is introduced and some extensions of strongly π-regular general rings are considered. Two equivalent characterizations on strongly π- reg...The concept of the strongly π-regular general ring （with or without unity） is introduced and some extensions of strongly π-regular general rings are considered. Two equivalent characterizations on strongly π- regular general rings are provided. It is shown that I is strongly π-regular if and only if, for each x ∈I, x^n =x^n＋1y = zx^n＋1 for n ≥ 1 and y, z ∈ I if and only if every element of I is strongly π-regular. It is also proved that every upper triangular matrix general ring over a strongly π-regular general ring is strongly π-regular and the trivial extension of the strongly π-regular general ring is strongly clean.展开更多
The approximation solvability of a generalized system for strongly g-r- pseudomonotonic nonlinear variational inequalities in Hilbert spaces is studied based on the convergence of the projection method. The results pr...The approximation solvability of a generalized system for strongly g-r- pseudomonotonic nonlinear variational inequalities in Hilbert spaces is studied based on the convergence of the projection method. The results presented in this paper improve, generalize and unify some recent results in the literature.展开更多
Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(Ⅱ), which is a valuable metal. In this study, the precipitation of Ni(Ⅱ) from strongly acidic wast...Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(Ⅱ), which is a valuable metal. In this study, the precipitation of Ni(Ⅱ) from strongly acidic wastewater using sodium dimethyldithiocarbamate(DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions(DDTC:Ni(Ⅱ) molar ratio = 4:1;temperature = 25 ℃), the Ni(Ⅱ) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(Ⅱ) to form DDTC –Ni precipitates. Further recovery experiments revealed that high-purity Ni O can be obtained by the calcination of DDTC –Ni precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO_(2), CS_(2), H_(2)O, CO_(2), and SO_(2). These results provide a basis for an effective Ni(Ⅱ) recovery method from strongly acidic wastewater.展开更多
Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system ...Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided.展开更多
In this paper, we investigate the Ishikawa iteration process in a p-uniformly smooth Banach space X. We prove that the Ishikawa iteration process converges strongly to the unique solution of the equation Tx=f when T i...In this paper, we investigate the Ishikawa iteration process in a p-uniformly smooth Banach space X. We prove that the Ishikawa iteration process converges strongly to the unique solution of the equation Tx=f when T is a Lipschitzian and strongly accretive operator frow X to X, or to the unique fixed point of T when T is a Lipschitzian and strictly pseudocontractive mapping from a nonempty closed convex subset K of X into itself. Our results are the extension and improvements of the earlier and recent results in this field.展开更多
The open-source finite element software,OpenSees,is widely used in the earthquake engineering community.However,the shell elements and explicit algorithm in OpenSees still require further improvements.Therefore,in thi...The open-source finite element software,OpenSees,is widely used in the earthquake engineering community.However,the shell elements and explicit algorithm in OpenSees still require further improvements.Therefore,in this work,a triangular shell element,NLDKGT,and an explicit algorithm are proposed and implemented in OpenSees.Specifically,based on the generalized conforming theory and the updated Lagrangian formulation,the proposed NLDKGT element is suitable for problems with complicated boundary conditions and strong nonlinearity.The accuracy and reliability of the NLDKGT element are validated through typical cases.Furthermore,by adopting the leapfrog integration method,an explicit algorithm in OpenSees and a modal damping model are developed.Finally,the stability and efficiency of the proposed shell element and explicit algorithm are validated through the nonlinear time-history analysis of a highrise building.展开更多
Let R be a ring and J（R） the Jacobson radical. An element a of R is called（strongly） J-clean if there is an idempotent e ∈ R and w ∈ J（R） such that a = e ＋ w（and ew = we）. The ring R is called a（strongly）...Let R be a ring and J（R） the Jacobson radical. An element a of R is called（strongly） J-clean if there is an idempotent e ∈ R and w ∈ J（R） such that a = e ＋ w（and ew = we）. The ring R is called a（strongly） J-clean ring provided that every one of its elements is（strongly） J-clean. We discuss, in the present paper,some properties of J-clean rings and strongly J-clean rings. Moreover, we investigate J-cleanness and strongly J-cleanness of generalized matrix rings. Some known results are also extended.展开更多
In this paper, the two-species prey-predator Lotka-Volterra model with the Holling＇s type III is discussed. By the method of coupled upper and lower solutions and its associated monotone iterations, the existence of ...In this paper, the two-species prey-predator Lotka-Volterra model with the Holling＇s type III is discussed. By the method of coupled upper and lower solutions and its associated monotone iterations, the existence of solutions for a strongly coupled elliptic system with homogeneous of Dirchlet boundary conditions is derived. These results show that this model admits at least one coexistence state if across-diffusions are weak.展开更多
As an important part of the early Mesozoic granites in the South Qinling tectonic belt(SQTB),the Guangtoushan pluton provides a material basis for research on the composition of magma sources and the effects of perite...As an important part of the early Mesozoic granites in the South Qinling tectonic belt(SQTB),the Guangtoushan pluton provides a material basis for research on the composition of magma sources and the effects of peritectic assemblage entrainment(PAE)on the changes in the granite composition.As shown by the results of LA-ICP-MS zircon U-Pb dating,the Guangtoushan pluton was emplaced during the Late Triassic(214-212 Ma)and was formed in the post-collision stage between the SQTB and the Yangtze plate.The collected samples had high SiO_(2)content and low Cr and Ni contents,indicating that the magmas did not undergo significant crust-mantle mixing during their evolution.The Guangtoushan granitoids were distributed along the trend line of magmatic fractional crystallization in the F-An-Or diagram.This result,combined with the relatively homogeneous Sr-Nd isotopic composition,implies that the Guangtoushan pluton underwent slight assimilation and contamination.As can be inferred from the comparison between the compositions of the Guangtoushan granitoids and various fluid-absent experimental melts,the magma sources of the Guangtoushan granitoids contain a variety of materials,such as graywackes,pyroclastic graywackes,and pelites and are not derived from lower crustal mafic rocks.The correlation between the maficity and the major and trace elements further indicates that the strongly peraluminous granitoids from the Guangtoushan pluton was formed by the partial melting of biotite-bearing crustal rocks and its magmatic evolution was accompanied by the entrainment of clinopyroxenes and accessory minerals.展开更多
An element a of a ring R is called uniquely strongly clean if it is the sum of an idempotent and a unit that commute, and in addition, this expression is unique. R is called uniquely strongly clean if every element of...An element a of a ring R is called uniquely strongly clean if it is the sum of an idempotent and a unit that commute, and in addition, this expression is unique. R is called uniquely strongly clean if every element of R is uniquely strongly clean. The uniquely strong cleanness of the triangular matrix ring is studied. Let R be a local ring. It is shown that any n × n upper triangular matrix ring over R is uniquely strongly clean if and only if R is uniquely bleached and R/J（R） ≈Z2.展开更多
文摘This note is to investigate the properties of strongly semipotent rings.It is proved that every strongly semipotent ring is a idempotent unit regular ring,i.e.,there exist a non-zero idempotent e and a unit u such that er=eu for all r∉J(R),where J(R)is the Jacobson radical of ring R.
基金supported by the National Science Foundation of China(22125804 and U24A20534)。
文摘Solid strong base catalysts have high potentials in a variety of reactions due to the advantages of negligible corrosion,easy separation,and high efficiency.However,two issues hinder the applications of such catalysts seriously,namely aggregation of basic sites and leaching of active species during reactions.The development of solid strong base catalysts with active sites that are highly dispersed and stable remains a pronounced challenge.In this work,we employed a two-step reduction strategy to anchor Na single atoms on nitrogen-doped porous carbon(NPC)support,producing a high-performance solid strongly basic catalyst named as Na1/NPC.The alkali precursor NaNO3was converted to Na_(2)O on NPC at 400℃,in which conventional solid base catalyst Na_(2)O/NPC was generated.Upon heat treatment at 850oC,Na_(2)O was further reduced to Na single atoms anchored on NPC,creating Na1/NPC.Experimental studies and theoretical calculations show that Na is structurally embedded on the support in penta-coordinated configuration(Na-C_(3)N_(2)).The synergistic effect of highly dispersed Na atoms and nitrogen doping results in uncommon catalytic activity and stability.In transesterification between methanol and ethylene carbonate to produce dimethyl carbonate(DMC),the yield of DMC reaches 48.4%over Na1/NPC,corresponding to a turnover frequency(TOF)of 129.4 h^(-1),which is far beyond the conventional counterpart Na_(2)O/NPC(63.3 h^(-1))and various reported solid base catalysts.The catalytic activity of Na1/NPC almost keeps constant during five cycles,while 87%of activity is lost for Na_(2)O/NPC due to the leaching of basic sites.This work might offer new ideas for the development of efficient single-atom solid strong base catalysts with high efficiency.
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 National Natural Science Foundation of China(Grant No.62363005).
文摘We investigate the blow-up effect of solutions for a non-homogeneous wave equation u_(tt)−∆u−∆u_(t)=I_(0+)^(α)(|u|^(p))+ω(x),where p>1,0≤α<1 andω(x)with∫_(R)^(N)ω(x)dx>0.By a way of combining the argument by contradiction with the test function techniques,we prove that not only any non-trivial solution blows up in finite time under 0<α<1,N≥1 and p>1,but also any non-trivial solution blows up in finite time underα=0,2≤N≤4 and p being the Strauss exponent.
基金Supported by the Guangxi Natural Science Foundation(Grant No.2021GXNSFBA196008)the Guangxi Science and Technology Development Program(Grant No.GuikeAD22035189).
文摘Multiphase flows widely exist in various scientific and engineering fields,and strongly compressible multiphase flows commonly occur in practical applications,which makes them an important part of computational fluid dynamics.In this study,an axisymmetric adaptive multiresolution smooth particle hydrodynamics(SPH)model is proposed to solve various strongly compressible multiphase flow problems.In the present model,the governing equations are discretized in cylindrical polar coordinates,and an improved volume adaptive scheme is developed to better solve the problem of excessive volume change in strongly compressible multiphase flows.On this basis,combined with the adaptive particle refinement technique,an adaptive multiresolution scheme is proposed in this study.In addition,the high-order differential operator and diffusion correction term are utilized to improve the accuracy and stability.The effectiveness of the model is verified by testing four typical strongly compressible multiphase flow problems.By comparing the results of adaptive multiresolution SPH with other numerical results or experimental data,we can conclude that the present SPH method effectively models strongly compressible multiphase flows.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406002)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301200)。
文摘We investigate the quantum dynamics of the 1D spinless Fermi-Hubbard model with a linear-tilted potential.Surprisingly in a strong resonance regime,we show that the model can be described by the kinetically constrained effective Hamiltonian,and it can be spontaneously divided into two commuting parts dubbed Hamiltonian dimerization,which are composed of two distinct sets of constrained nearest-neighbor hopping terms:one set acting exclusively on odd bonds and the other on even bonds.Specifically it is shown that each part can be independently mapped onto the well-known PXP model;therefore the dimerized Hamiltonian is equivalent to a two-fold PXP model.As a consequence,we numerically demonstrate this system can host the so-called quantum many-body scars,which present dynamical revivals and ergodicity-breaking behaviors.However,in sharp contrast with traditional quantum many-body scars,here the scarring states in our model driven by different parts of the Hamiltonian will revive in different periods,and those of double parts can display a biperiodic revival pattern,both originating from the Hamiltonian dimerization.Besides,the condition of off-resonance is also discussed,and we show the crossover from quantum many-body scar to ergodicity breaking is diagnosed via level statistics.Our model provides a platform for understanding the interplay of Hilbert space fragmentation and the constrained quantum systems.
文摘A new type strongly gain coupled (GC) DFB laser and a new type self alignment spot size converter (SA SSC) are proposed and successfully fabricated.The strongly GC DFB laser is monolithically integrated with the SA SSC with three step epitaxies.A high single mode yield and large side mode suppression ratio is obtained from the strongly GC DFB laser.A near circle far field pattern is obtained by using the SA SSC.
文摘The authors obtain the growth and covering theorems for strongly starlike mappings of order α on bounded starlike circular domains.This kind of domain discussed is rather general,since the domain must be starlike if exists a normalized biholomorphic starlike mapping on it.
基金financially supported by the National Natural Science Foundation of China(No.50803054)Zhejiang Provincial Nature Science Foundation of China(No.Y4100204)
文摘Inspired by the self-polymerization and strong adhesion characteristics of dopamine in aqueous conditions, a novel hydrophilic nanofiltration （NF） membrane was fabricated by simply dipping polysulfone （PSf） ultrafiltration （UF） substrate in dopamine solution. The changes in surface chemical composition and morphology of membranes were determined by Fourier transform infrared spectroscopy （FTIR-ATR）, X-ray photoelectron spectroscopy （XPS）, scanning electron microscopy （SEM） and atomic force microscopy （AFM）. The experimental results indicated that the self-polymerized dopamine formed an ultrathin and defect-free barrier layer on the PSf UF membrane. The surface hydrophilicity of membranes was evaluated through water contact angle measurements. It was found that membrane hydrophilicity was significantly improved after coating a polydopamine （pDA） layer, especially after double coating. The dyes filtration experiments showed that the double-coated membranes were able to reject completely the dyes of brilliant blue, congo red and methyl orange with a pure water flux of 83.7 L/（mE.h） under 0.6 MPa. The zeta potential determination revealed the positively-charged characteristics of PSf/pDA composite membrane in NF process. The salt rejection of the membranes was characterized by 0.01 mmol/L of salts filtration experiment. It was demonstrated that the salts rejections followed the sequence： NaC1 〈 NaaSO4 〈 MgSO4 〈 MgC12 〈 CaCl2, and the rejection to CaC12 reached 68.7%. Moreover, the composite NF membranes showed a good stability in water-phase filtration process.
基金Project supported by the National Natural Science Foundation of China （Grant Nos 10474023 and 10674050） and Specialized Research Fund for the Doctoral Program of Higher Education （Grant No 20060574006）.
文摘The fundamental and second order strongly nonlocal solitons of the nonlocal nonlinear Schrodinger equation for several types of nonlocal responses are calculated by Ritz＇s variational method. For a specific type of nonlocal response, the solutions of the strongly nonlocal solitons with the same beam width but different degrees of nonlocality are identical except for an amplitude factor. For a nonlocal case where the nonlocal response function decays in direct proportion to the mth power of the distance near the source point, the power and the phase constant of the strongly nonlocal soliton are in inverse proportion to the （m ＋ 2）th power of its beam width.
基金The Foundation for Excellent Doctoral Dissertationof Southeast University (NoYBJJ0507)the National Natural ScienceFoundation of China (No10571026)the Natural Science Foundation ofJiangsu Province (NoBK2005207)
文摘The concept of the strongly π-regular general ring （with or without unity） is introduced and some extensions of strongly π-regular general rings are considered. Two equivalent characterizations on strongly π- regular general rings are provided. It is shown that I is strongly π-regular if and only if, for each x ∈I, x^n =x^n＋1y = zx^n＋1 for n ≥ 1 and y, z ∈ I if and only if every element of I is strongly π-regular. It is also proved that every upper triangular matrix general ring over a strongly π-regular general ring is strongly π-regular and the trivial extension of the strongly π-regular general ring is strongly clean.
基金Supported by the Science and Technology Research Project of Chinese Ministry of Education (206123)
文摘The approximation solvability of a generalized system for strongly g-r- pseudomonotonic nonlinear variational inequalities in Hilbert spaces is studied based on the convergence of the projection method. The results presented in this paper improve, generalize and unify some recent results in the literature.
基金supported by the National Key Research and Development Project (No. 2019YFC1907603 )the National Natural Science Foundation of China (Nos. 21976195 , 21707153 )。
文摘Strongly acidic wastewater produced in nonferrous metal smelting industries often contains high concentrations of Ni(Ⅱ), which is a valuable metal. In this study, the precipitation of Ni(Ⅱ) from strongly acidic wastewater using sodium dimethyldithiocarbamate(DDTC) as the precipitant was evaluated. The effects of various factors on precipitation were investigated, and the precipitation mechanism was also identified. Finally, the nickel in the precipitates was recovered following a pyrometallurgical method. The results show that, under optimised conditions(DDTC:Ni(Ⅱ) molar ratio = 4:1;temperature = 25 ℃), the Ni(Ⅱ) removal efficiency reached 99.3% after 10 min. In strongly acidic wastewater, the dithiocarbamate group of DDTC can react with Ni(Ⅱ) to form DDTC –Ni precipitates. Further recovery experiments revealed that high-purity Ni O can be obtained by the calcination of DDTC –Ni precipitates, with the nickel recovery efficiency reaching 98.2%. The gas released during the calcination process was composed of NO_(2), CS_(2), H_(2)O, CO_(2), and SO_(2). These results provide a basis for an effective Ni(Ⅱ) recovery method from strongly acidic wastewater.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11175094 and 91221205)the National Basic Research Program of China(Grant No.2015CB921002)partially supported by the Basic Research Fund of Beijing Institute of Technology(Grant No.20141842005)
文摘Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided.
基金The project supported by the Science and Technology Development Fund of Shanghai Higher Learning
文摘In this paper, we investigate the Ishikawa iteration process in a p-uniformly smooth Banach space X. We prove that the Ishikawa iteration process converges strongly to the unique solution of the equation Tx=f when T is a Lipschitzian and strongly accretive operator frow X to X, or to the unique fixed point of T when T is a Lipschitzian and strictly pseudocontractive mapping from a nonempty closed convex subset K of X into itself. Our results are the extension and improvements of the earlier and recent results in this field.
基金The authors would like to acknowledge the financial supports of Beijing Natural Science Foundation(No.8182025).
文摘The open-source finite element software,OpenSees,is widely used in the earthquake engineering community.However,the shell elements and explicit algorithm in OpenSees still require further improvements.Therefore,in this work,a triangular shell element,NLDKGT,and an explicit algorithm are proposed and implemented in OpenSees.Specifically,based on the generalized conforming theory and the updated Lagrangian formulation,the proposed NLDKGT element is suitable for problems with complicated boundary conditions and strong nonlinearity.The accuracy and reliability of the NLDKGT element are validated through typical cases.Furthermore,by adopting the leapfrog integration method,an explicit algorithm in OpenSees and a modal damping model are developed.Finally,the stability and efficiency of the proposed shell element and explicit algorithm are validated through the nonlinear time-history analysis of a highrise building.
文摘Let R be a ring and J（R） the Jacobson radical. An element a of R is called（strongly） J-clean if there is an idempotent e ∈ R and w ∈ J（R） such that a = e ＋ w（and ew = we）. The ring R is called a（strongly） J-clean ring provided that every one of its elements is（strongly） J-clean. We discuss, in the present paper,some properties of J-clean rings and strongly J-clean rings. Moreover, we investigate J-cleanness and strongly J-cleanness of generalized matrix rings. Some known results are also extended.
基金Supported by the National Natural Science Foundation of China(1057601310871075)
文摘In this paper, the two-species prey-predator Lotka-Volterra model with the Holling＇s type III is discussed. By the method of coupled upper and lower solutions and its associated monotone iterations, the existence of solutions for a strongly coupled elliptic system with homogeneous of Dirchlet boundary conditions is derived. These results show that this model admits at least one coexistence state if across-diffusions are weak.
基金funded by the State Key Program of National Natural Science of China(Grant No.41730426)the National Natural Science Foundation of China(Grant Nos.41872066,41702069 and 41602040)the Research Fund of Hebei Provincial Bureau of Geology and Mineral Resources(454-0601-YBN-DXXP)。
文摘As an important part of the early Mesozoic granites in the South Qinling tectonic belt(SQTB),the Guangtoushan pluton provides a material basis for research on the composition of magma sources and the effects of peritectic assemblage entrainment(PAE)on the changes in the granite composition.As shown by the results of LA-ICP-MS zircon U-Pb dating,the Guangtoushan pluton was emplaced during the Late Triassic(214-212 Ma)and was formed in the post-collision stage between the SQTB and the Yangtze plate.The collected samples had high SiO_(2)content and low Cr and Ni contents,indicating that the magmas did not undergo significant crust-mantle mixing during their evolution.The Guangtoushan granitoids were distributed along the trend line of magmatic fractional crystallization in the F-An-Or diagram.This result,combined with the relatively homogeneous Sr-Nd isotopic composition,implies that the Guangtoushan pluton underwent slight assimilation and contamination.As can be inferred from the comparison between the compositions of the Guangtoushan granitoids and various fluid-absent experimental melts,the magma sources of the Guangtoushan granitoids contain a variety of materials,such as graywackes,pyroclastic graywackes,and pelites and are not derived from lower crustal mafic rocks.The correlation between the maficity and the major and trace elements further indicates that the strongly peraluminous granitoids from the Guangtoushan pluton was formed by the partial melting of biotite-bearing crustal rocks and its magmatic evolution was accompanied by the entrainment of clinopyroxenes and accessory minerals.
基金The National Natural Science Foundation of China(No.10971024)the Specialized Research Fund for the Doctoral Program of Higher Education(No.200802860024)the Natural Science Foundation of Jiangsu Province(No.BK2010393)
文摘An element a of a ring R is called uniquely strongly clean if it is the sum of an idempotent and a unit that commute, and in addition, this expression is unique. R is called uniquely strongly clean if every element of R is uniquely strongly clean. The uniquely strong cleanness of the triangular matrix ring is studied. Let R be a local ring. It is shown that any n × n upper triangular matrix ring over R is uniquely strongly clean if and only if R is uniquely bleached and R/J（R） ≈Z2.
