We calculate the two-proton decay width of the6 Be nucleus employing the schematic densitydependent contact potential for the proton-proton pairing interaction. The decay width is calculated with a time-dependent meth...We calculate the two-proton decay width of the6 Be nucleus employing the schematic densitydependent contact potential for the proton-proton pairing interaction. The decay width is calculated with a time-dependent method, in which the two-proton emission is described as a time-evolution of a threebody meta-stable state. Model-dependence of the two-proton decay width has been shown by comparing the results obtained with the two different pairing models, schematic density-dependent contact and Minnesota interactions, which have zero and finite ranges, respectively.展开更多
In this article,a comprehensive study of the fission process of Th,U,Pu,and Cm isotopes using a Yukawa-folded meanfield plus standard pairing model is presented.The study focused on analyzing the effects of the pairin...In this article,a comprehensive study of the fission process of Th,U,Pu,and Cm isotopes using a Yukawa-folded meanfield plus standard pairing model is presented.The study focused on analyzing the effects of the pairing interaction on the fragment mass distribution and its dependence on nuclear elongation.The significant role of pairing interactions in the fragment mass distributions of^(230)Th,^(234)U,^(240)Pu,and^(246)Cm was demonstrated.Numerical analysis revealed that increasing the pairing interaction strength decreased the asymmetric fragment mass distribution and increased the symmetric distribution.Furthermore,the odd-even mass differences at symmetric and asymmetric fission points were examined,highlighting their sensitivity to changes in the pairing interaction strength.Systematic analysis of the Th,U,Pu,and Cm isotope fragment mass distributions demonstrated the effectiveness of the model in reproducing the experimental data.In addition,the effects of the zero-point energy and half-width parameter on the fragment mass distribution for^(240)Pu were explored.Thus,this study provides valuable insights into the fission process by emphasizing the importance of pairing interactions and their relationship with nuclear elongation.展开更多
Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the for...Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.展开更多
Cocrystallization of the palladium acetate cluster Pd_(3)(OAc)_(6)(abbreviated as[Pd_(3)])with electron-deficient iodine(I)-based perfluoroarenes(ArFI:iodopentafluorobenzene,4-iodoheptafluorotoluene,1,4-diiodotetraflu...Cocrystallization of the palladium acetate cluster Pd_(3)(OAc)_(6)(abbreviated as[Pd_(3)])with electron-deficient iodine(I)-based perfluoroarenes(ArFI:iodopentafluorobenzene,4-iodoheptafluorotoluene,1,4-diiodotetrafluorobenzene,1,2-diiodotetrafluorobenzene,and octafluoro-4,4’-diiodo-1,1-biphenyl)and iodinefree octafluoronaphthalene gave a series of six cocrystals[Pd_(3)]·(arene)studied by single-crystal X-ray diffractometry.Significant intermolecular noncovalent interactions were verified by a density functional theory study,molecular electrostatic potential and Hirshfeld surface analyses,a combined QTAIM/NCPlot approach,and NBO and energy framework calculations.In five out of six structures,the aromatic rings coupled with cluster[Pd_(3)]via lone pair-π-(ArF)-hole interactions.The iodine-containing arenes,ArFI,were additionally involved in halogen bonding with carboxylate O centers,but inorganic-organic stacking still remained the structure-determining interaction.In the stacking,the electron-rich PdO_(4)plane behaved as a five-center nucleophile providing oxygen lone pairs in addition to the dz_(2)-PdII orbital;this plane complemented theπ-acidic surface of the arenes,affording highly polar circular stacking,where organics wrapped inorganics.展开更多
The microscopic mechanism of nine experimentally observed bands in ^178W is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions. The exp...The microscopic mechanism of nine experimentally observed bands in ^178W is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions. The experimental results, including the moments of inertia and angular momentum alignments of nine bands in ^178W, are reproduced well by the particle-number conserving calculations, in which no free parameter is involved. Calculations demonstrate that occurrence of sharp backbending comes mainly from the contribution of high-j intruder orbitals vi13/2 or πh11/2 and their interference effect with orbitals near the Fermi surface. Theω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each cranked orbital are analyzed.展开更多
The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four ...The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.展开更多
As one of the most important catalysts in polyethylene industry,Phillips catalyst(CrO_x/SiO_2)was quite unique for its activation by ethylene monomer without using any activator like alkyl-aluminium or MAO.In this wor...As one of the most important catalysts in polyethylene industry,Phillips catalyst(CrO_x/SiO_2)was quite unique for its activation by ethylene monomer without using any activator like alkyl-aluminium or MAO.In this work,the density functional theory(DFT)calculation combined with paired interacting orbitals(PIO)method was applied for the theoretical studies on coordination reaction mechanism between ethylene monomer and two model catalysts namely Cr(Ⅱ)(OH)_2(M1) and silsesquioxane-supported Cr(Ⅱ)(M2)as surfac...展开更多
The paper discusses the researches that formed the basis of the study of the transition of “ordering-phase separation” and the reasons for such transition occurrence. Experimental results have presented what diffusi...The paper discusses the researches that formed the basis of the study of the transition of “ordering-phase separation” and the reasons for such transition occurrence. Experimental results have presented what diffusion pairs are and how they occur in binary and multicomponent alloys. The paper illustrates that the chemical bonds between atoms are realized on the principle of pair interaction in both solid and liquid states of the alloy. The process of separating a multi-component ABC alloy into diffusion pairs A/B, A/C, and B/C occurs in a liquid solution, where the diffusion mobility of atoms is very high, and the resistance of the environment is relatively low. The driving force of such a process is the chemical attraction between like and unlike atoms, that is, the tendency to phase separation and the tendency to ordering. Quenching the liquid alloy into the water fixes a microstructure consisting of microscopic areas corresponding in composition to one or another diffusion pairs. The paper shows what exactly should be done so that such a branch of science as Materials Science could get rid of the empirical approach when creating new alloys.展开更多
A modified selectively infective phage (SIP) is developed to facilitate the selection of interacting antibody antigen pairs from a large single chain antibody (scFv) library in vivo. The system is constructed with a m...A modified selectively infective phage (SIP) is developed to facilitate the selection of interacting antibody antigen pairs from a large single chain antibody (scFv) library in vivo. The system is constructed with a modified helper phage M13KO7 and phagemid pCANTAB 5 E. The antigen fused to the C terminal of N1 N2 domain and the scFv to the N terminal of CT domain of the gIIIp of filamentous phage are encoded on the phage and phagemid vectors respectively. The phages produced by co transformants restore infectivity via interaction between antigen and antibody fusions in the cell periplasm. In a model system, the scFv fragment of the anti hemagglutinin 17/9 antibody and its corresponding antigen are detected in the presence of a 10 5 fold excess of a non interacting control pairs, which demonstrates this system to be very sensitive and facile to screen a large single chain antibody library.展开更多
The isospin and density dependent effective pairing interaction is revisited by fitting the neutron gaps from the microscopic calculations for the neutron matter and the symmetric nuclear matter.The neutron pairing ga...The isospin and density dependent effective pairing interaction is revisited by fitting the neutron gaps from the microscopic calculations for the neutron matter and the symmetric nuclear matter.The neutron pairing gaps for 1S0 channel for asymmetric nuclear matter are obtained from the BCS gap equation with a realistic bare nucleon-nucleon interaction in the Skyrme mean field.It is shown that the neutron gaps obtained from the new effective pairing interaction for the asymmetric nuclear matter are much improved and agree well with the microscopic results.展开更多
The Nilsson mean-field plus the extended pairing model for well-deformed nuclei is applied to some representative rare earth examples. The binding energies, some low-lying pair-excited states and evenodd mass differen...The Nilsson mean-field plus the extended pairing model for well-deformed nuclei is applied to some representative rare earth examples. The binding energies, some low-lying pair-excited states and evenodd mass differences of Er, Yb and Hf isotopes are calculated systematically within the proton frozen-pair excitation limit. A comparison with experimental data for these nuclei shows that the results of the extended pairing model are better than those for the standard pairing model with the BCS approximation and the nearest-orbit pairing model.展开更多
The short-range pair interaction consumes most of the CPU time in molecular dynamics(MD)simulations.The inherent computation sparsity makes it challenging to achieve high-performance kernel on the emerging many-core a...The short-range pair interaction consumes most of the CPU time in molecular dynamics(MD)simulations.The inherent computation sparsity makes it challenging to achieve high-performance kernel on the emerging many-core architecture.In this paper,we present a highly efficient short-range force kernel on the Sunway,a novel many-core architecture with many unique features.The parallel efficiency of this algorithm on the Sunway many-core processor is strongly limited by the poor data locality and write conflicts.To enhance the data locality,we adopt a super cluster based neighbor list with an appropriate granularity that fits in the local memory of computing cores.In the absence of a low overhead locking mechanism,using data-privatization force array is a more feasible method to avoid write conflicts,but results in the large overhead of data reduction.We adopt a dual-slice partitioning scheme for both hardware resources and computing tasks,which utilizes the on-chip data communication to reduce data reduction overhead and provide load balancing.Moreover,we exploit the single instruction multiple data(SIMD)parallelism and perform instruction reordering of the force kernel on this many-core processor.The experimental results show that the optimized force kernel obtains a performance speedup of 226x compared with the reference implementation and achieves 20%of peak flop rate on the Sunway many-core processor.展开更多
Heterogeneous systems with both Central Processing Units （CPUs） and Graphics Processing Units （GPUs） are frequently used to accelerate short-ranged Molecular Dynamics （MD） simulations. The most time-consuming ta...Heterogeneous systems with both Central Processing Units （CPUs） and Graphics Processing Units （GPUs） are frequently used to accelerate short-ranged Molecular Dynamics （MD） simulations. The most time-consuming task in short-ranged MD simulations is the computation of particle-to-particle interac- tions. Beyond a certain distance, these interactions decrease to zero. To minimize the operations to investi- gate distance, previous works have tiled interactions by employing the spatial attribute, which increases the memory access and GPU computations, hence decreasing performance. Other studies ignore the spatial attribute and construct an all-versus-all interaction matrix, which has poor scalability. This paper presents an improved algorithm. The algorithm first bins particles into voxels according to the spatial attributes, and then tiles the all-versus-all matrix into voxel-versus-voxel sub-matrixes. Only the sub-matrixes between neighbor- ing voxels are computed on the GPU. Therefore, the algorithm reduces the distance examine operations and limits additional memory access and GPU computations. This paper also adopts a multi-level program- ming model to implement the algorithm on multi-nodes of Tianhe-lA. By employing （1） a patch design to ex- ploit parallelism across the simulation domain, （2） a communication overlapping method to overlap the communications between CPUs and GPUs, and （3） a dynamic workload balancing method to adjust the workloads among compute nodes, the implementation achieves a speedup of 4.16x on one NVIDIA Tesla M2050 GPU compared to a 2.93 GHz six-core Intel Xeon X5670 CPU. In addition, it runs 2.41x faster on 256 compute nodes of Tianhe-lA （with two CPUs and one GPU inside a node） than on 256 GPU-excluded nodes.展开更多
We report the synthesis and X-ray structure of the dimeric zinc(Ⅱ)compound[Zn(tda)(phen)]2·H2tda,(tda=thiodiacetic acid,phen=1,10-phenanthroline)hereafter Zn(tda)(phen),and a single crystal EPR study of Zn(tda)(...We report the synthesis and X-ray structure of the dimeric zinc(Ⅱ)compound[Zn(tda)(phen)]2·H2tda,(tda=thiodiacetic acid,phen=1,10-phenanthroline)hereafter Zn(tda)(phen),and a single crystal EPR study of Zn(tda)(phen)doped with Cu(Ⅱ)ions.Zn(tda)(phen)is isomorphous to its Cu(Ⅱ)analogue.The EPR spectra show a central signal composed of one to four resonances assigned to Cu–Zn heterodimers,flanked by less intense satellite signals assigned to Cu–Cu homodimers.Analysis of single crystal EPR data allowed us to determine the g-and A-matrices of the Cu(Ⅱ)ion and the anisotropic ZFS parameters of the homodimer.Within the experimental error,the Cu(Ⅱ)g-matrix obtained for the diluted compound was identical to that previously determined by us in pure Cu(tda)(phen).The ZFS is shown to be dominated by magnetic dipolar coupling between the unpaired electrons mainly centered around the Cu(Ⅱ)ions,although partially delocalized over the equatorial copper ligands.DFT calculations yielded spin population values compatible with those determined from the analysis of the anisotropic ZFS assuming a distributed dipole model.The information obtained from the diluted compound was used to evaluate the interdimeric exchange interaction between dimeric units in pure Cu(tda)(phen).The comparison between both point and distributed dipole approximations is discussed with reference to the analysis of the EPR data.展开更多
The effects of the tensor force on the and decay nuclear matrix elements(NMEs)of,,,and are studied using the Hartree-Fock-Bogoliubov(HFB)plus proton-neutron quasi-particle random phase approximation(pnQRPA)model based...The effects of the tensor force on the and decay nuclear matrix elements(NMEs)of,,,and are studied using the Hartree-Fock-Bogoliubov(HFB)plus proton-neutron quasi-particle random phase approximation(pnQRPA)model based on the Skyrme energy density functional.We include the full spectra of intermediate states with up to the energy cutoff E=60 MeV,which is sufficient for convergence of NME calculations.The isovector(IV)pairing and tensor interactions are considered in both HFB and QRPA calculations,while the isoscalar(IS)pairing interaction is included only in QRPA calculations.We found that the tensor force shifts Gamow-Teller(GT)transition strengths substantially to low-energy regions and enhances the decay NME.The inclusion of tensor force enhances the NME by approximately 13%for and and 30%for and,for a fixed IS pairing strength.We found that the intermediate 2-state makes an important contribution to the NME,which is slightly enhanced by the inclusion of the tensor force.We also found that the contribution of the state makes important differences through the inclusion of the tensor force,which enhances the contribution largely.However when the IS pairing strength is increased,the contributions from 1+states are rapidly reduced to be very small,resulting in even negative contributions.Thus,tensor and IS pairing effects cancel each other,making the net effect on the NME relatively small.Due to this cancellation,if the IS pairing strength is optimized separately for cases with and without the tensor interaction to reproduce the experimental NME,the consequent NME with the tensor interaction is close to that without the tensor interaction within a 10%difference.展开更多
The present study aims to investigate the substrate specificity of peroxidase(POD),an enzyme held responsible for enzymatic browning,in the presence of caffeic acid,guaiacol,chlorogenic acid and catechol.The use of in...The present study aims to investigate the substrate specificity of peroxidase(POD),an enzyme held responsible for enzymatic browning,in the presence of caffeic acid,guaiacol,chlorogenic acid and catechol.The use of in silico studies provided additional support for the identification of optimal substrate candidates.Considering the Vmax/Km(EU/mL.min.mM)values obtained,caffeic acid was found to have the highest value(11.85)and to be the best substrate for POD.The inhibitory mechanism of ascorbic acid,citric acid and salicylic acid on the activity of POD was studied in the presence of caffeic acid.Competitive inhibition was observed in the kinetic studies involving ascorbic acid and salicylic acid,whereas non-competitive inhibition was observed in the case of citric acid.The lowest calculated dissociation constant(Ki)of the enzyme-inhibitor complex was that of salicylic acid(0.044 mM).Furthermore,the in vitro Ki results for the inhibitors used were consistent with the in silico studies.The mechanism of POD inhibition by salicylic acid in the presence of a caffeic acid substrate was explained by molecular docking studies.The POD inhibition has been attributed to a decrease in substrate oxidation as a result of ferric(H2O2)interactions with salicylic acid,in addition to a decrease in enzyme stabilization as a result of Pi-lone pair interactions.展开更多
文摘We calculate the two-proton decay width of the6 Be nucleus employing the schematic densitydependent contact potential for the proton-proton pairing interaction. The decay width is calculated with a time-dependent method, in which the two-proton emission is described as a time-evolution of a threebody meta-stable state. Model-dependence of the two-proton decay width has been shown by comparing the results obtained with the two different pairing models, schematic density-dependent contact and Minnesota interactions, which have zero and finite ranges, respectively.
基金This work was supported by the National Natural Science Foundation of China(Nos.12275115 and 12175097)the Educational Department of Liaoning Province(No.LJKMZ20221410).
文摘In this article,a comprehensive study of the fission process of Th,U,Pu,and Cm isotopes using a Yukawa-folded meanfield plus standard pairing model is presented.The study focused on analyzing the effects of the pairing interaction on the fragment mass distribution and its dependence on nuclear elongation.The significant role of pairing interactions in the fragment mass distributions of^(230)Th,^(234)U,^(240)Pu,and^(246)Cm was demonstrated.Numerical analysis revealed that increasing the pairing interaction strength decreased the asymmetric fragment mass distribution and increased the symmetric distribution.Furthermore,the odd-even mass differences at symmetric and asymmetric fission points were examined,highlighting their sensitivity to changes in the pairing interaction strength.Systematic analysis of the Th,U,Pu,and Cm isotope fragment mass distributions demonstrated the effectiveness of the model in reproducing the experimental data.In addition,the effects of the zero-point energy and half-width parameter on the fragment mass distribution for^(240)Pu were explored.Thus,this study provides valuable insights into the fission process by emphasizing the importance of pairing interactions and their relationship with nuclear elongation.
基金financially supported by the National Natural Science Foundation of China (22078132 and 22108103)Open Funding Project of the National Key Laboratory of Biochemical Engineering (2021KF-02)+3 种基金China Postdoctoral Science Foundation (2021M691301)Jiangsu Agricultural Independent Innovation Fund Project (CX(21)3079)Graduate Research Innovation Program of Jiangsu Province (KYCX20-3040)China Postdoctoral Science Foundation (2021M691301)。
文摘Molecularly imprinted polymers (MIPs) have great potential as adsorbents for selective adsorption and separation of nucleoside compounds,but effectively enhancing the affinity of recognition sites by adjusting the forces between template molecules and functional monomers remains an important challenge.In this work,a surface imprinting strategy was used to construct bowl-shaped molecularly imprinted composite sorbents (BHPN@MIPs) based on polydopamine (PDA) particles and have achieved selective separation and purification of 2'-deoxyadenosine (dA).Where by the base complementary pairing interaction of the combined template molecule d A and the pyrimidine functional monomer can enhance the preassembly force,and the hydrophilic bowl-shaped PDA can provide a larger storage space contact efficiency of d A in the test solution,causing the site utilization much higher and improving the kinetic adsorption performance.The equilibrium adsorption time and maximum adsorption capacity of60 min and 328.45μmol·g^(-1)were observed by static adsorption experiments,and the selectivity experimental results showed an imprinting factor IF of 1.30.After four adsorption–desorption cycles,the initial adsorption equilibrium adsorption capacity of BHPN@MIPs still retained 91.14%.By evaluating the selective adsorption of d A in spiked human serum solutions,BHPN@MIPs can be used to selectively enrich and analyze target d A in complex biological samples.
基金the Russian Science Foundation grants 19-13-00338(crystal engineering study)and 21-73-10030(molecular design ofπ-andσ-hole donors)the equipment of the shared experimental facilities supported by N.S.Kurnakov Institute of General and Inorganic Chemistry RAS.BG and AF acknowledge the MICIU/AEI from Spain for financial support of the computational study(project numbers CTQ2017-85821-R and PID2020-115637GB-I00,FEDER funds)。
文摘Cocrystallization of the palladium acetate cluster Pd_(3)(OAc)_(6)(abbreviated as[Pd_(3)])with electron-deficient iodine(I)-based perfluoroarenes(ArFI:iodopentafluorobenzene,4-iodoheptafluorotoluene,1,4-diiodotetrafluorobenzene,1,2-diiodotetrafluorobenzene,and octafluoro-4,4’-diiodo-1,1-biphenyl)and iodinefree octafluoronaphthalene gave a series of six cocrystals[Pd_(3)]·(arene)studied by single-crystal X-ray diffractometry.Significant intermolecular noncovalent interactions were verified by a density functional theory study,molecular electrostatic potential and Hirshfeld surface analyses,a combined QTAIM/NCPlot approach,and NBO and energy framework calculations.In five out of six structures,the aromatic rings coupled with cluster[Pd_(3)]via lone pair-π-(ArF)-hole interactions.The iodine-containing arenes,ArFI,were additionally involved in halogen bonding with carboxylate O centers,but inorganic-organic stacking still remained the structure-determining interaction.In the stacking,the electron-rich PdO_(4)plane behaved as a five-center nucleophile providing oxygen lone pairs in addition to the dz_(2)-PdII orbital;this plane complemented theπ-acidic surface of the arenes,affording highly polar circular stacking,where organics wrapped inorganics.
基金National Natural Science Foundation of China under Grant No.10675006
文摘The microscopic mechanism of nine experimentally observed bands in ^178W is investigated using the particle-number conserving method of the cranked shell model with monopole and quadrupole paring interactions. The experimental results, including the moments of inertia and angular momentum alignments of nine bands in ^178W, are reproduced well by the particle-number conserving calculations, in which no free parameter is involved. Calculations demonstrate that occurrence of sharp backbending comes mainly from the contribution of high-j intruder orbitals vi13/2 or πh11/2 and their interference effect with orbitals near the Fermi surface. Theω variation of the occupation probability of each cranked orbital and the contribution to moment of inertia from each cranked orbital are analyzed.
基金Supported by the National Natural Science Foundation of China under Grant No 11105001the Anhui Provincial Natural Science Foundation under Grant Nos 1408085QA22 and 1608085MA09
文摘The single photon scattering properties in a pair of waveguides coupled by a whispering-gallery resonator in- teracting with a semiconductor quantum dot are investigated theoretically. The two waveguides support four possible ports for an incident single photon. The quantum dot is considered a V-type system. The incident direction-dependent single photon scattering properties are studied and equal-output probability from the four ports for a single photon incident is discussed. The influences of backscattering between the two modes of the whispering-gallery resonator for incident direction-dependent single photon scattering properties are also pre- sented.
基金the National Natural Science Foundation of China(No.20744004 and No.20774025).
文摘As one of the most important catalysts in polyethylene industry,Phillips catalyst(CrO_x/SiO_2)was quite unique for its activation by ethylene monomer without using any activator like alkyl-aluminium or MAO.In this work,the density functional theory(DFT)calculation combined with paired interacting orbitals(PIO)method was applied for the theoretical studies on coordination reaction mechanism between ethylene monomer and two model catalysts namely Cr(Ⅱ)(OH)_2(M1) and silsesquioxane-supported Cr(Ⅱ)(M2)as surfac...
文摘The paper discusses the researches that formed the basis of the study of the transition of “ordering-phase separation” and the reasons for such transition occurrence. Experimental results have presented what diffusion pairs are and how they occur in binary and multicomponent alloys. The paper illustrates that the chemical bonds between atoms are realized on the principle of pair interaction in both solid and liquid states of the alloy. The process of separating a multi-component ABC alloy into diffusion pairs A/B, A/C, and B/C occurs in a liquid solution, where the diffusion mobility of atoms is very high, and the resistance of the environment is relatively low. The driving force of such a process is the chemical attraction between like and unlike atoms, that is, the tendency to phase separation and the tendency to ordering. Quenching the liquid alloy into the water fixes a microstructure consisting of microscopic areas corresponding in composition to one or another diffusion pairs. The paper shows what exactly should be done so that such a branch of science as Materials Science could get rid of the empirical approach when creating new alloys.
文摘A modified selectively infective phage (SIP) is developed to facilitate the selection of interacting antibody antigen pairs from a large single chain antibody (scFv) library in vivo. The system is constructed with a modified helper phage M13KO7 and phagemid pCANTAB 5 E. The antigen fused to the C terminal of N1 N2 domain and the scFv to the N terminal of CT domain of the gIIIp of filamentous phage are encoded on the phage and phagemid vectors respectively. The phages produced by co transformants restore infectivity via interaction between antigen and antibody fusions in the cell periplasm. In a model system, the scFv fragment of the anti hemagglutinin 17/9 antibody and its corresponding antigen are detected in the presence of a 10 5 fold excess of a non interacting control pairs, which demonstrates this system to be very sensitive and facile to screen a large single chain antibody library.
基金supported partially by the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China (Grant Nos.10875150 and 10875157)
文摘The isospin and density dependent effective pairing interaction is revisited by fitting the neutron gaps from the microscopic calculations for the neutron matter and the symmetric nuclear matter.The neutron pairing gaps for 1S0 channel for asymmetric nuclear matter are obtained from the BCS gap equation with a realistic bare nucleon-nucleon interaction in the Skyrme mean field.It is shown that the neutron gaps obtained from the new effective pairing interaction for the asymmetric nuclear matter are much improved and agree well with the microscopic results.
基金Supported by U.S.National Science Foundation (PHY-0500291 & OCI-0904874)Southeastern Universities Research Association,National Natural Science Foundation of China (10775064)+2 种基金Liaoning Education Department Fund (2007R28)Doctoral Program Foundation of State Education Ministry of China (20102136110002)LSU-LNNU Joint Research Program (9961)
文摘The Nilsson mean-field plus the extended pairing model for well-deformed nuclei is applied to some representative rare earth examples. The binding energies, some low-lying pair-excited states and evenodd mass differences of Er, Yb and Hf isotopes are calculated systematically within the proton frozen-pair excitation limit. A comparison with experimental data for these nuclei shows that the results of the extended pairing model are better than those for the standard pairing model with the BCS approximation and the nearest-orbit pairing model.
基金The work was supported by the National Key Research and Development Program of China under Grant No. 2018YFB0204102。
文摘The short-range pair interaction consumes most of the CPU time in molecular dynamics(MD)simulations.The inherent computation sparsity makes it challenging to achieve high-performance kernel on the emerging many-core architecture.In this paper,we present a highly efficient short-range force kernel on the Sunway,a novel many-core architecture with many unique features.The parallel efficiency of this algorithm on the Sunway many-core processor is strongly limited by the poor data locality and write conflicts.To enhance the data locality,we adopt a super cluster based neighbor list with an appropriate granularity that fits in the local memory of computing cores.In the absence of a low overhead locking mechanism,using data-privatization force array is a more feasible method to avoid write conflicts,but results in the large overhead of data reduction.We adopt a dual-slice partitioning scheme for both hardware resources and computing tasks,which utilizes the on-chip data communication to reduce data reduction overhead and provide load balancing.Moreover,we exploit the single instruction multiple data(SIMD)parallelism and perform instruction reordering of the force kernel on this many-core processor.The experimental results show that the optimized force kernel obtains a performance speedup of 226x compared with the reference implementation and achieves 20%of peak flop rate on the Sunway many-core processor.
基金Supported by the National Natural Science Foundation of China (Nos. 61170049 and 60903044)the National High-Tech Research and Development (863) Program of China (Nos. 2012AA01A301 and 2012AA010903)
文摘Heterogeneous systems with both Central Processing Units （CPUs） and Graphics Processing Units （GPUs） are frequently used to accelerate short-ranged Molecular Dynamics （MD） simulations. The most time-consuming task in short-ranged MD simulations is the computation of particle-to-particle interac- tions. Beyond a certain distance, these interactions decrease to zero. To minimize the operations to investi- gate distance, previous works have tiled interactions by employing the spatial attribute, which increases the memory access and GPU computations, hence decreasing performance. Other studies ignore the spatial attribute and construct an all-versus-all interaction matrix, which has poor scalability. This paper presents an improved algorithm. The algorithm first bins particles into voxels according to the spatial attributes, and then tiles the all-versus-all matrix into voxel-versus-voxel sub-matrixes. Only the sub-matrixes between neighbor- ing voxels are computed on the GPU. Therefore, the algorithm reduces the distance examine operations and limits additional memory access and GPU computations. This paper also adopts a multi-level program- ming model to implement the algorithm on multi-nodes of Tianhe-lA. By employing （1） a patch design to ex- ploit parallelism across the simulation domain, （2） a communication overlapping method to overlap the communications between CPUs and GPUs, and （3） a dynamic workload balancing method to adjust the workloads among compute nodes, the implementation achieves a speedup of 4.16x on one NVIDIA Tesla M2050 GPU compared to a 2.93 GHz six-core Intel Xeon X5670 CPU. In addition, it runs 2.41x faster on 256 compute nodes of Tianhe-lA （with two CPUs and one GPU inside a node） than on 256 GPU-excluded nodes.
文摘We report the synthesis and X-ray structure of the dimeric zinc(Ⅱ)compound[Zn(tda)(phen)]2·H2tda,(tda=thiodiacetic acid,phen=1,10-phenanthroline)hereafter Zn(tda)(phen),and a single crystal EPR study of Zn(tda)(phen)doped with Cu(Ⅱ)ions.Zn(tda)(phen)is isomorphous to its Cu(Ⅱ)analogue.The EPR spectra show a central signal composed of one to four resonances assigned to Cu–Zn heterodimers,flanked by less intense satellite signals assigned to Cu–Cu homodimers.Analysis of single crystal EPR data allowed us to determine the g-and A-matrices of the Cu(Ⅱ)ion and the anisotropic ZFS parameters of the homodimer.Within the experimental error,the Cu(Ⅱ)g-matrix obtained for the diluted compound was identical to that previously determined by us in pure Cu(tda)(phen).The ZFS is shown to be dominated by magnetic dipolar coupling between the unpaired electrons mainly centered around the Cu(Ⅱ)ions,although partially delocalized over the equatorial copper ligands.DFT calculations yielded spin population values compatible with those determined from the analysis of the anisotropic ZFS assuming a distributed dipole model.The information obtained from the diluted compound was used to evaluate the interdimeric exchange interaction between dimeric units in pure Cu(tda)(phen).The comparison between both point and distributed dipole approximations is discussed with reference to the analysis of the EPR data.
基金Supported by the National Natural Science Foundation of China(11575120,11822504,12075104)National Key Research and Development(R&D)programe of China(2021YFA1601500)+2 种基金Science Specialty Program of Sichuan University(2020SCUNL210)the support from Chinese Academy of Sciences for the project of Young Scientists in Basic Research(YSBR-099)"From 0 to 1 innovative"program.This work was partially supported by JSPS KAKENHI(JP19K03858)。
文摘The effects of the tensor force on the and decay nuclear matrix elements(NMEs)of,,,and are studied using the Hartree-Fock-Bogoliubov(HFB)plus proton-neutron quasi-particle random phase approximation(pnQRPA)model based on the Skyrme energy density functional.We include the full spectra of intermediate states with up to the energy cutoff E=60 MeV,which is sufficient for convergence of NME calculations.The isovector(IV)pairing and tensor interactions are considered in both HFB and QRPA calculations,while the isoscalar(IS)pairing interaction is included only in QRPA calculations.We found that the tensor force shifts Gamow-Teller(GT)transition strengths substantially to low-energy regions and enhances the decay NME.The inclusion of tensor force enhances the NME by approximately 13%for and and 30%for and,for a fixed IS pairing strength.We found that the intermediate 2-state makes an important contribution to the NME,which is slightly enhanced by the inclusion of the tensor force.We also found that the contribution of the state makes important differences through the inclusion of the tensor force,which enhances the contribution largely.However when the IS pairing strength is increased,the contributions from 1+states are rapidly reduced to be very small,resulting in even negative contributions.Thus,tensor and IS pairing effects cancel each other,making the net effect on the NME relatively small.Due to this cancellation,if the IS pairing strength is optimized separately for cases with and without the tensor interaction to reproduce the experimental NME,the consequent NME with the tensor interaction is close to that without the tensor interaction within a 10%difference.
文摘The present study aims to investigate the substrate specificity of peroxidase(POD),an enzyme held responsible for enzymatic browning,in the presence of caffeic acid,guaiacol,chlorogenic acid and catechol.The use of in silico studies provided additional support for the identification of optimal substrate candidates.Considering the Vmax/Km(EU/mL.min.mM)values obtained,caffeic acid was found to have the highest value(11.85)and to be the best substrate for POD.The inhibitory mechanism of ascorbic acid,citric acid and salicylic acid on the activity of POD was studied in the presence of caffeic acid.Competitive inhibition was observed in the kinetic studies involving ascorbic acid and salicylic acid,whereas non-competitive inhibition was observed in the case of citric acid.The lowest calculated dissociation constant(Ki)of the enzyme-inhibitor complex was that of salicylic acid(0.044 mM).Furthermore,the in vitro Ki results for the inhibitors used were consistent with the in silico studies.The mechanism of POD inhibition by salicylic acid in the presence of a caffeic acid substrate was explained by molecular docking studies.The POD inhibition has been attributed to a decrease in substrate oxidation as a result of ferric(H2O2)interactions with salicylic acid,in addition to a decrease in enzyme stabilization as a result of Pi-lone pair interactions.
