Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfull...Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2.展开更多
Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmeth...Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.展开更多
A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation ...A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation results show that this method can drive the static tracking error to zero quickly and keep good robustness and adaptability at the same time. In addition, the algorithm is very easy to be implemented with low computational complexity.展开更多
The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated...The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximized the energy of the solution,which was opposite to the Tikhonov regularization where the energy was minimized.However,combined with box-constraints,the deregularization forced the solution to be close to the binary set.It further exploited the box-constrained dichotomous coordinate descent algorithm and adapted it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down as K2.8 and K2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.In addition,most operations in the detector are additions and bit-shifts.This makes the proposed technique attractive for fixed-point hardware implementation.展开更多
Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degr...Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degree centrality, betweenness centra- lity and closeness centrality are taken into consideration in the proposed method. Numerical examples are used to illustrate the effectiveness of the proposed method.展开更多
Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines...Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines. All of the compounds synthesized were characterized by elemental analysis, IR, 1H NMR. The crystal structures of [C 5H 5NH][Ph 2Sn(μ 2-SCH 2COO)Cl](6) and [PhMeNH 2]· [Ph 2Sn(μ 2-SCH 2COO)Cl](8) were determined by X-ray diffraction. In the crystal structure, there were trigonal bipyramid geometries with five-coordinated tin atom and hydrogen-bonding interaction between anionic and cationic ions. Crystals of compound 6 were monoclinic, space group P2 1/n, a= 1.034 7(4) nm, b=1.396 8(5) nm, c=1.405 6(5) nm, β=95.366(6)°, Z=4; Crystals of compound 8 were monoclinic, space group P2 1/c, a=0.922 9(3) nm, b=1.334 5(5) nm, c= 1.838 5(7) nm, β=93.673(7)°, Z=4.展开更多
文摘Two new transition-metal coordination polymers,{[Cd(oba)(L)_(2)]·H_(2)O}_n(1)and[Cd(4-nph)(L)_(2)]_n(2)(H_(2)oba=4,4'-oxydibenzoic acid,4-H_(2)nph=4-nitrophthalic acid,L=2,2'-biimidazole),were successfully synthesized under hydrothermal conditions and characterized structurally by IR spectroscopy,elemental analyses,single-crystal X-ray diffraction,powder X-ray diffraction,and thermogravimetric analysis.The results of single-crystal X-ray diffraction show that complex 1 presents a 1D zigzag chain structure and further extends to a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.Meanwhile,complex 2 has a zero-dimensional structure and also extends to form a 2D network through N—H…O hydrogen bonds andπ-πstacking interactions.In addition,both 1and 2 exhibited luminescent properties in the solid state.Furthermore,quantum chemical calculations were carried out on the"molecular fragments"extracted from the crystal structures of 1 and 2 using the PBE0/LANL2DZ method constructed by the Gaussian 16 program.The calculated values signify a significant covalent interaction between the coordination atoms and the Cd(Ⅱ)ions.CCDC:2332173,1;2332176,2.
文摘Two new coordination polymers,[Ni(Hpdc)(bib)(H_(2)O)]_(n)(1)and{[Ni(bib)_(3)](ClO_(4))_(2)}_(n)(2),were prepared by mixing Ni^(2+),3,5⁃pyrazoledicarboxylic acid(H3pdc)/p⁃nitrobenzoic acid and 1,4⁃bis(imidazol⁃1⁃ylmethyl)butane(bib)by a hydrothermal method,respectively.X⁃ray crystallography reveals a 2D network constructed by six⁃coordinated Ni(Ⅱ)centers,bib,and Hpdc2-ligands in complex 1,while a 2D network is built by Ni(Ⅱ)and bib ligands in 2.Furthermore,the quantum⁃chemical calculations have been performed on‘molecular fragments’extracted from the crystal structure of 1 using the PBE0/LANL2DZ method in Gaussian 16 and the VASP program.CCDC:2343794,1;2343798,2.
基金This project was supported by the National Natural Science Foundation (No. 69875010).
文摘A nonlinear visual mapping model is presented to replace the image Jacobian relation for uncalibrated hand/eye coordination. A new visual tracking controller based on artificial neural network is designed. Simulation results show that this method can drive the static tracking error to zero quickly and keep good robustness and adaptability at the same time. In addition, the algorithm is very easy to be implemented with low computational complexity.
文摘The presented iterative multiuser detection technique was based on joint deregularized and box-constrained solution to quadratic optimization with iterations similar to that used in the nonstationary Tikhonov iterated algorithm.The deregularization maximized the energy of the solution,which was opposite to the Tikhonov regularization where the energy was minimized.However,combined with box-constraints,the deregularization forced the solution to be close to the binary set.It further exploited the box-constrained dichotomous coordinate descent algorithm and adapted it to the nonstationary iterative Tikhonov regularization to present an efficient detector.As a result,the worst-case and average complexity are reduced down as K2.8 and K2.5 floating point operation per second,respectively.The development improves the "efficient frontier" in multiuser detection,which is illustrated by simulation results.In addition,most operations in the detector are additions and bit-shifts.This makes the proposed technique attractive for fixed-point hardware implementation.
基金supported by the National Natural Science Foundation of China(61174022)the National High Technology Research and Development Program of China(863 Program)(2013AA013801)+2 种基金the Open Funding Project of State Key Laboratory of Virtual Reality Technology and Systems,Beihang University(BUAA-VR-14KF-02)the General Research Program of the Science Supported by Sichuan Provincial Department of Education(14ZB0322)the Fundamental Research Funds for the Central Universities(XDJK2014D008)
文摘Identifying influential nodes in complex networks is still an open issue. In this paper, a new comprehensive centrality mea- sure is proposed based on the Dempster-Shafer evidence theory. The existing measures of degree centrality, betweenness centra- lity and closeness centrality are taken into consideration in the proposed method. Numerical examples are used to illustrate the effectiveness of the proposed method.
文摘Five-coordinated anionic tin(Ⅳ) complexes with the form [Ph 2Sn(μ 2-SCH 2COO)Cl]·[R nNH 4-n] were synthesized by the reaction of mercaptoacetic acid with diphenyltin dichloride in the presence of organic amines. All of the compounds synthesized were characterized by elemental analysis, IR, 1H NMR. The crystal structures of [C 5H 5NH][Ph 2Sn(μ 2-SCH 2COO)Cl](6) and [PhMeNH 2]· [Ph 2Sn(μ 2-SCH 2COO)Cl](8) were determined by X-ray diffraction. In the crystal structure, there were trigonal bipyramid geometries with five-coordinated tin atom and hydrogen-bonding interaction between anionic and cationic ions. Crystals of compound 6 were monoclinic, space group P2 1/n, a= 1.034 7(4) nm, b=1.396 8(5) nm, c=1.405 6(5) nm, β=95.366(6)°, Z=4; Crystals of compound 8 were monoclinic, space group P2 1/c, a=0.922 9(3) nm, b=1.334 5(5) nm, c= 1.838 5(7) nm, β=93.673(7)°, Z=4.
