A new 2-D Bi(3+) coordination polymer {Bi4(μ3-O)2(μ4-O)2(C7H3NO4)2}n(1,C7H3NO4 = pyridine-2,6-dicarboxylate) containing(6,5)-connected topological sheet with the Schl?fli symbol of(4~4·6~3·8...A new 2-D Bi(3+) coordination polymer {Bi4(μ3-O)2(μ4-O)2(C7H3NO4)2}n(1,C7H3NO4 = pyridine-2,6-dicarboxylate) containing(6,5)-connected topological sheet with the Schl?fli symbol of(4~4·6~3·8~4·12~4)(4~5·6~4·8) has been synthesized by an ionothermal method using the ionic liquid 1-ethyl-3-methylimidazolium bromide([Emim]Br) as solvent,and characterized by C,H and N elemental analysis,energy-dispersive X-ray spectroscopy(EDS),infrared spectrum(IR spectrum) and single-crystal X-ray diffraction.The results indicate that 1 belongs to the monoclinic system,space group P21/n with a = 13.766(7),b = 4.142(2),c = 16.439(8) ?,β = 99.099(9)°,Z = 2,V = 925.6(8) ?~3,Dc = 4.414 g·cm^(-3),F(000) = 1064,μ = 37.985 mm-1,the final R = 0.0326,wR = 0.0727 and S = 1.022.The molecular structural units [Bi4(μ3-O)2(μ4-O)2(C7H3NO4)2] are connected to each other via bridging O atoms,extending into an interesting 2-D layered structure.These resulting layers are further assembled by weak C-H…O hydrogen bonds into a 3-D supramolecular architecture.Moreover,its thermal stability and the luminescent properties have been also studied.展开更多
Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis(2-methyl imidazole) ligands, namely, {[Cd2(tdc)2(bip)2]·7H20}n (1) and [Cd(tdc)(bib)]n (2) (Hgtdc = 3,4-thiophenedi...Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis(2-methyl imidazole) ligands, namely, {[Cd2(tdc)2(bip)2]·7H20}n (1) and [Cd(tdc)(bib)]n (2) (Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-(imidazol-2-methyl)propane and bib = 1,4-bis(imidazol-2-methyl)butane), have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional (2D) layered network with 3-connected (6,3) topology, which is further connected into a three- dimensional (3D) supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis(imidazol-2-methyl) ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature.展开更多
针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进IN...针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进INFO-Bi-LSTM模型)。采用Circle混沌映射和反向学习产生高质量初始化种群,引入自适应t分布提升INFO算法跳出局部最优解和全局搜索的能力。选取改进INFO-Bi-LSTM模型和多种预测模型对炉内外联合脱硫过程中4种典型工况下的SO_(2)排放质量浓度进行预测,将预测结果进行验证对比。结果表明:改进INFO算法的寻优能力得到提升,并且改进INFO-Bi-LSTM模型精度更高,更加适用于SO_(2)排放质量浓度的预测,可为变工况下的脱硫控制提供控制理论支撑。展开更多
基金Project supported by the National Natural Science Foundation of China(No.21601095)
文摘A new 2-D Bi(3+) coordination polymer {Bi4(μ3-O)2(μ4-O)2(C7H3NO4)2}n(1,C7H3NO4 = pyridine-2,6-dicarboxylate) containing(6,5)-connected topological sheet with the Schl?fli symbol of(4~4·6~3·8~4·12~4)(4~5·6~4·8) has been synthesized by an ionothermal method using the ionic liquid 1-ethyl-3-methylimidazolium bromide([Emim]Br) as solvent,and characterized by C,H and N elemental analysis,energy-dispersive X-ray spectroscopy(EDS),infrared spectrum(IR spectrum) and single-crystal X-ray diffraction.The results indicate that 1 belongs to the monoclinic system,space group P21/n with a = 13.766(7),b = 4.142(2),c = 16.439(8) ?,β = 99.099(9)°,Z = 2,V = 925.6(8) ?~3,Dc = 4.414 g·cm^(-3),F(000) = 1064,μ = 37.985 mm-1,the final R = 0.0326,wR = 0.0727 and S = 1.022.The molecular structural units [Bi4(μ3-O)2(μ4-O)2(C7H3NO4)2] are connected to each other via bridging O atoms,extending into an interesting 2-D layered structure.These resulting layers are further assembled by weak C-H…O hydrogen bonds into a 3-D supramolecular architecture.Moreover,its thermal stability and the luminescent properties have been also studied.
基金supported by the National Natural Science of Foundation of China(No.21305060)
文摘Two coordination polymers constructed from 3,4-thiophenedicarboxylic acid and bis(2-methyl imidazole) ligands, namely, {[Cd2(tdc)2(bip)2]·7H20}n (1) and [Cd(tdc)(bib)]n (2) (Hgtdc = 3,4-thiophenedicarboxylic acid, bip = 1,3-bis-(imidazol-2-methyl)propane and bib = 1,4-bis(imidazol-2-methyl)butane), have been synthesized and structurally characterized by single-crystal X-ray diffraction. Structural analyses reveal that 1 exhibits a two-dimensional (2D) layered network with 3-connected (6,3) topology, which is further connected into a three- dimensional (3D) supramolecular structure by intermolecular hydrogen bonds. However, 2 features a 2D network which can be rationalized as a 4-connected sql net. The results indicate the subtle difference of auxiliary bis(imidazol-2-methyl) ligands may lead to diverse architectures. Moreover, they exhibit luminescence emission in the solid state at room temperature.
文摘针对火电机组SO_(2)排放质量浓度的影响因素众多,难以准确预测的问题,提出一种改进向量加权平均(weighted mean of vectors,INFO)算法与双向长短期记忆(bi-directional long short term memory,Bi-LSTM)神经网络相结合的预测模型(改进INFO-Bi-LSTM模型)。采用Circle混沌映射和反向学习产生高质量初始化种群,引入自适应t分布提升INFO算法跳出局部最优解和全局搜索的能力。选取改进INFO-Bi-LSTM模型和多种预测模型对炉内外联合脱硫过程中4种典型工况下的SO_(2)排放质量浓度进行预测,将预测结果进行验证对比。结果表明:改进INFO算法的寻优能力得到提升,并且改进INFO-Bi-LSTM模型精度更高,更加适用于SO_(2)排放质量浓度的预测,可为变工况下的脱硫控制提供控制理论支撑。