Perovskite-structured nickelates,ReNiO_(3)(Re=rare earth),have long garnered significant research interest due to their sharp and highly tunable metal-insulator transitions(MITs).Doping the parent compound ReNiO_(3)wi...Perovskite-structured nickelates,ReNiO_(3)(Re=rare earth),have long garnered significant research interest due to their sharp and highly tunable metal-insulator transitions(MITs).Doping the parent compound ReNiO_(3)with alkaline earth metal can substantially suppress this MIT.Recently,intriguing superconductivity has been discovered in doped infinite-layer nickelates(ReNiO_(2)),while the mechanism behind A-site doping-suppressed MIT in the parent compound ReNiO_(3)remains unclear.To address this problem,we grew a series of Nd_(1−x)Sr_(x)NiO_(3)(NSNO,x=0–0.2)thin films and conducted systematic electrical transport measurements.Our resistivity and Hall measurements suggest that Sr-induced excessive holes are not the primary reason for MIT suppression.Instead,first-principles calculations indicate that Sr cations,with larger ionic radius,suppress breathing mode distortions and promote charge transfer between oxygen and Ni cations.This process weakens Ni–O bond disproportionation and Ni^(2+)/Ni^(4+)charge disproportionation.Such significant modulations in lattice and electronic structures convert the ground state from a charge-disproportionated antiferromagnetic insulator to a paramagnetic metal,thereby suppressing the MIT.This scenario is further supported by the weakened MIT observed in the tensile-strained NSNO/SrTiO_(3)(001)films.Our work reveals the A-side doping-modulated electrical transport of perovskite nickelate films,providing deeper insights into novel electric phases in these strongly correlated nickelate systems.展开更多
Dipyrido [3, 2-a:2,3-c] phenazine moiety has been introduced as neutral ligand in europium complex. Therefore, a new europium complex with saturated emission, strong fluorescent intensity and good solubility was desi...Dipyrido [3, 2-a:2,3-c] phenazine moiety has been introduced as neutral ligand in europium complex. Therefore, a new europium complex with saturated emission, strong fluorescent intensity and good solubility was designed and synthesized for the first time. Its photoluminescence and UV properties were examined. The experimental results showed that this new Eu-complex could be used as red electroluminescent materials.展开更多
Authors investigate the model that two two level atoms interact with a single mode cavity. The formulation of the time evolution operator for the two atom Jaynes Cummings model is presented by the bare states approach...Authors investigate the model that two two level atoms interact with a single mode cavity. The formulation of the time evolution operator for the two atom Jaynes Cummings model is presented by the bare states approach. Besides, squeezing effect of the cavity field is studied and some novel features are obtained.展开更多
The crystal structure of novel coordination polymer with excellent characteristic luminescence of Eu3+, the three-dimentional network of {Eu2(p-BDC)3(Phen)2(H2O)2}n is presented.
Previously, researchers raised the accuracy for a robot′s hand to track a specified path in Car-tesian space mainly through increasing the number of knots on the path and the number of the path′s segments, which res...Previously, researchers raised the accuracy for a robot′s hand to track a specified path in Car-tesian space mainly through increasing the number of knots on the path and the number of the path′s segments, which results in the heavier online computational burden for the robot controller. Aiming at overcoming this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method. Through selecting some extra knots on the specified hand path by a certain rule and introducing a sinusoidal function to the joint displacement equation of each segment, this method can greatly raise the path tracking accuracy of robot′s hand and does not change the number of the path′s segments. It also does not increase markedly the computational burden of robot controller. The result of simulation indicates that this method is very effective, and has important value in increasing the application of industrial robots.展开更多
Double pylorus is one of the rare anomalies of the gastrointestinal tract,it can be congenital or acquired.In this case we report a case of double pylorus because of chronic peptic ulcer.Upper GI endoscopy revealed ga...Double pylorus is one of the rare anomalies of the gastrointestinal tract,it can be congenital or acquired.In this case we report a case of double pylorus because of chronic peptic ulcer.Upper GI endoscopy revealed gastroduodenal fistula located on the lesser curve of the antrum,the patient’s symptoms were improved rapidly by intensive antiulcer treatment.展开更多
The simplified Newton method, at the expense of fast convergence, reduces the work required by Newton method by reusing the initial Jacobian matrix. The composite Newton method attempts to balance the trade-off betwee...The simplified Newton method, at the expense of fast convergence, reduces the work required by Newton method by reusing the initial Jacobian matrix. The composite Newton method attempts to balance the trade-off between expense and fast convergence by composing one Newton step with one simplified Newton step. Recently, Mehrotra suggested a predictor-corrector variant of primal-dual interior point method for linear programming. It is currently the interiorpoint method of the choice for linear programming. In this work we propose a predictor-corrector interior-point algorithm for convex quadratic programming. It is proved that the algorithm is equivalent to a level-1 perturbed composite Newton method. Computations in the algorithm do not require that the initial primal and dual points be feasible. Numerical experiments are made.展开更多
The numerical methods for miscible displacment in aggregated or sorbing medium are considered. A mixed finite element method is adopted for the pressure equation. The concentration in the mobile water is approximated ...The numerical methods for miscible displacment in aggregated or sorbing medium are considered. A mixed finite element method is adopted for the pressure equation. The concentration in the mobile water is approximated by a combination of a Galerkin finite element method and the method of characteristics and the concentration in immobile water is approximated by a standard Galerkin method. The moving mesh technique which depends on time t is adopted here. The moving meshes can vary in different spacial domains with different variable times. Optima error estimates in energy norm and L2 norm are obtained under certain constraints.展开更多
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1406404 and 2020YFA0309100)the National Natural Science Foundation of China(Grant Nos.12074365,12374094,12304153,U2032218,and 11974326),the National Natural Science Foundation of China(Grant No.12274120)+6 种基金CAS Project for Young Scientists in Basic Research(Grant No.YSBR-084)the Fundamental Research Funds for the Central Universities(Grant Nos.WK9990000102 and WK2030000035)Anhui Provincial Natural Science Foundation(Grant No.2308085MA15)Hefei Science Center CAS Foundation(Grant Nos.2021HSC-CIP017 and 2016HSC-IU06)the China Postdoctoral Science Foundation(Grant No.2022M713060)the starting funds from Northwest Universitysupport from the Vienna Scientific Cluster(VSC)for the first-principles calculations。
文摘Perovskite-structured nickelates,ReNiO_(3)(Re=rare earth),have long garnered significant research interest due to their sharp and highly tunable metal-insulator transitions(MITs).Doping the parent compound ReNiO_(3)with alkaline earth metal can substantially suppress this MIT.Recently,intriguing superconductivity has been discovered in doped infinite-layer nickelates(ReNiO_(2)),while the mechanism behind A-site doping-suppressed MIT in the parent compound ReNiO_(3)remains unclear.To address this problem,we grew a series of Nd_(1−x)Sr_(x)NiO_(3)(NSNO,x=0–0.2)thin films and conducted systematic electrical transport measurements.Our resistivity and Hall measurements suggest that Sr-induced excessive holes are not the primary reason for MIT suppression.Instead,first-principles calculations indicate that Sr cations,with larger ionic radius,suppress breathing mode distortions and promote charge transfer between oxygen and Ni cations.This process weakens Ni–O bond disproportionation and Ni^(2+)/Ni^(4+)charge disproportionation.Such significant modulations in lattice and electronic structures convert the ground state from a charge-disproportionated antiferromagnetic insulator to a paramagnetic metal,thereby suppressing the MIT.This scenario is further supported by the weakened MIT observed in the tensile-strained NSNO/SrTiO_(3)(001)films.Our work reveals the A-side doping-modulated electrical transport of perovskite nickelate films,providing deeper insights into novel electric phases in these strongly correlated nickelate systems.
基金This work was supported by the National Natural Science Foundation of China (No29992530-6) and Provincial Natural Science Foundation of Hunan (00JJY2043).
文摘Dipyrido [3, 2-a:2,3-c] phenazine moiety has been introduced as neutral ligand in europium complex. Therefore, a new europium complex with saturated emission, strong fluorescent intensity and good solubility was designed and synthesized for the first time. Its photoluminescence and UV properties were examined. The experimental results showed that this new Eu-complex could be used as red electroluminescent materials.
文摘Authors investigate the model that two two level atoms interact with a single mode cavity. The formulation of the time evolution operator for the two atom Jaynes Cummings model is presented by the bare states approach. Besides, squeezing effect of the cavity field is studied and some novel features are obtained.
基金We are grateful to State Key Project of Foundational Research of China (G1998061308) and the National Natural Science Foundation of China (G200071004) for support of this research.
文摘The crystal structure of novel coordination polymer with excellent characteristic luminescence of Eu3+, the three-dimentional network of {Eu2(p-BDC)3(Phen)2(H2O)2}n is presented.
基金Foundation of the Robotics Laboratory, Chinese Academy of Sciences (No: RL200002)
文摘Previously, researchers raised the accuracy for a robot′s hand to track a specified path in Car-tesian space mainly through increasing the number of knots on the path and the number of the path′s segments, which results in the heavier online computational burden for the robot controller. Aiming at overcoming this drawback, the authors propose a new kind of real-time accurate hand path tracking and joint trajectory planning method. Through selecting some extra knots on the specified hand path by a certain rule and introducing a sinusoidal function to the joint displacement equation of each segment, this method can greatly raise the path tracking accuracy of robot′s hand and does not change the number of the path′s segments. It also does not increase markedly the computational burden of robot controller. The result of simulation indicates that this method is very effective, and has important value in increasing the application of industrial robots.
文摘Double pylorus is one of the rare anomalies of the gastrointestinal tract,it can be congenital or acquired.In this case we report a case of double pylorus because of chronic peptic ulcer.Upper GI endoscopy revealed gastroduodenal fistula located on the lesser curve of the antrum,the patient’s symptoms were improved rapidly by intensive antiulcer treatment.
文摘The simplified Newton method, at the expense of fast convergence, reduces the work required by Newton method by reusing the initial Jacobian matrix. The composite Newton method attempts to balance the trade-off between expense and fast convergence by composing one Newton step with one simplified Newton step. Recently, Mehrotra suggested a predictor-corrector variant of primal-dual interior point method for linear programming. It is currently the interiorpoint method of the choice for linear programming. In this work we propose a predictor-corrector interior-point algorithm for convex quadratic programming. It is proved that the algorithm is equivalent to a level-1 perturbed composite Newton method. Computations in the algorithm do not require that the initial primal and dual points be feasible. Numerical experiments are made.
文摘The numerical methods for miscible displacment in aggregated or sorbing medium are considered. A mixed finite element method is adopted for the pressure equation. The concentration in the mobile water is approximated by a combination of a Galerkin finite element method and the method of characteristics and the concentration in immobile water is approximated by a standard Galerkin method. The moving mesh technique which depends on time t is adopted here. The moving meshes can vary in different spacial domains with different variable times. Optima error estimates in energy norm and L2 norm are obtained under certain constraints.
