Solvent dependent assembly obtained two novel Ni coordination polymers with H_2 tbtpa and flexible 1,2-bix ligand（H_2tbtpa = tetrabromoterephthalic acid and 1,2-bix = 1,2-bis（imidazol-1-ylmethyl）benzene）,formulate...Solvent dependent assembly obtained two novel Ni coordination polymers with H_2 tbtpa and flexible 1,2-bix ligand（H_2tbtpa = tetrabromoterephthalic acid and 1,2-bix = 1,2-bis（imidazol-1-ylmethyl）benzene）,formulated as [Ni_（0.5）（tbtpa）_（0.5）（1,2-bix）·（H_2O）]_n（1） and [Ni（tbtpa）（1,2-bix）（H_2O）_2]_n（2）.They have been structurally characterized by single-crystal and powder X-ray diffraction,elemental analysis,FT-IR spectra and TGA.Compound 1 crystalizes in triclinic,space group P1 with a = 9.0276（4）,b = 10.0012（6）,c = 11.4955（5） A,α = 69.121（5）,β = 76.398（4）,γ = 89.668（4）o,C_（36）H_（32）Br_4 Ni N_8O_6,Mr = 1051.04,V = 939.05（8） A^3,Z = 1,Dc = 1.859 g·cm^-3,μ = 6.222 mm^-1,F（000） = 520,8.502≤2θ≤134.16°,λ（Cu Kα） = 1.54184 A,T = 294（6） K,the final R = 0.0750,w R = 0.1988 and S = 1.033.Compound 2 crystalizes in triclinic,space group P1 with a = 11.1257（7）,b = 11.5062（6）,c = 12.3529（4） A,α = 88.861（3）,β = 84.572（4）,γ = 64.235（6）o,C_（22）H_（18）Br_4 Ni N_4O_6,Mr = 812.75,V = 1417.36（1） A^3,Z = 2,Dc = 1.904 g·cm^-3,μ = 7.968 mm^-1,F（000） = 788,7.2≤2θ≤134.1°,λ（Cu Kα） = 1.54184 A,T = 294（6） K,the final R = 0.0414,w R = 0.0865 and S = 1.025.1 shows a two-dimensional（4,4）-sql topology and 2 manifests a three-dimensional 6~58 Cd SO_4 topology coordination polymer network.展开更多
ICM （Independent Continuous Mapping） method can solve topological optimization problems with the minimized weight as the objective and subjected to displacement constraints. To get a clearer topological configuratio...ICM （Independent Continuous Mapping） method can solve topological optimization problems with the minimized weight as the objective and subjected to displacement constraints. To get a clearer topological configuration, by introducing the discrete condition of topological variables and integrating with the original objective, an optimal model with multi-objectives is formulated to make the topological variables approach 0 or 1 as near as possible, and the model reduces the effect of deleting rate on the result. The image-filtering method is employed to eliminate the checkerboard patterns and mesh dependence that occurred in the topology optimization of a continuum structure. The computational efficiency is enhanced through selecting quasi-active displacement constraints and a design region. Numerical examples indicate that this algorithm is robust and practicable, though the number of iterations is slightly increased with respect to the original algorithm.展开更多
Circular double stranded DNA has different topological states which are defined by their linking numbers. Equilibrium distribution of linking numbers can be obtained by closing
基金Supported by the National Natural Science Foundation of China(NSFC)(No.21271117)National Students'Innovation and Entrepreneurship Training Program(201410425060)
文摘Solvent dependent assembly obtained two novel Ni coordination polymers with H_2 tbtpa and flexible 1,2-bix ligand（H_2tbtpa = tetrabromoterephthalic acid and 1,2-bix = 1,2-bis（imidazol-1-ylmethyl）benzene）,formulated as [Ni_（0.5）（tbtpa）_（0.5）（1,2-bix）·（H_2O）]_n（1） and [Ni（tbtpa）（1,2-bix）（H_2O）_2]_n（2）.They have been structurally characterized by single-crystal and powder X-ray diffraction,elemental analysis,FT-IR spectra and TGA.Compound 1 crystalizes in triclinic,space group P1 with a = 9.0276（4）,b = 10.0012（6）,c = 11.4955（5） A,α = 69.121（5）,β = 76.398（4）,γ = 89.668（4）o,C_（36）H_（32）Br_4 Ni N_8O_6,Mr = 1051.04,V = 939.05（8） A^3,Z = 1,Dc = 1.859 g·cm^-3,μ = 6.222 mm^-1,F（000） = 520,8.502≤2θ≤134.16°,λ（Cu Kα） = 1.54184 A,T = 294（6） K,the final R = 0.0750,w R = 0.1988 and S = 1.033.Compound 2 crystalizes in triclinic,space group P1 with a = 11.1257（7）,b = 11.5062（6）,c = 12.3529（4） A,α = 88.861（3）,β = 84.572（4）,γ = 64.235（6）o,C_（22）H_（18）Br_4 Ni N_4O_6,Mr = 812.75,V = 1417.36（1） A^3,Z = 2,Dc = 1.904 g·cm^-3,μ = 7.968 mm^-1,F（000） = 788,7.2≤2θ≤134.1°,λ（Cu Kα） = 1.54184 A,T = 294（6） K,the final R = 0.0414,w R = 0.0865 and S = 1.025.1 shows a two-dimensional（4,4）-sql topology and 2 manifests a three-dimensional 6~58 Cd SO_4 topology coordination polymer network.
基金supported by the National Natural Science Foundation of China(10472003)Beijing Natural Science(3002002)+1 种基金Beijing Educational Committee Foundations(KM200410005019)Suspensofled by American MSC Company.
文摘ICM （Independent Continuous Mapping） method can solve topological optimization problems with the minimized weight as the objective and subjected to displacement constraints. To get a clearer topological configuration, by introducing the discrete condition of topological variables and integrating with the original objective, an optimal model with multi-objectives is formulated to make the topological variables approach 0 or 1 as near as possible, and the model reduces the effect of deleting rate on the result. The image-filtering method is employed to eliminate the checkerboard patterns and mesh dependence that occurred in the topology optimization of a continuum structure. The computational efficiency is enhanced through selecting quasi-active displacement constraints and a design region. Numerical examples indicate that this algorithm is robust and practicable, though the number of iterations is slightly increased with respect to the original algorithm.
基金supported by the Young Investigator Award received by Yan in 2006the Foundation for the Visiting PhD Candidate of the Chinese Academy of Science received by Liu in 2006
文摘Circular double stranded DNA has different topological states which are defined by their linking numbers. Equilibrium distribution of linking numbers can be obtained by closing
