拐点是图像很重要的特征,包含图像的主要结构信息,拐点检测对图像配准、目标识别和三维重建等任务的处理都有着非常重要的作用。从研究轮廓上点的曲率出发,针对传统基于轮廓的拐点检测算法对噪声和局部变化敏感而造成检测结果不稳定的问...拐点是图像很重要的特征,包含图像的主要结构信息,拐点检测对图像配准、目标识别和三维重建等任务的处理都有着非常重要的作用。从研究轮廓上点的曲率出发,针对传统基于轮廓的拐点检测算法对噪声和局部变化敏感而造成检测结果不稳定的问题,提出一种间接反映轮廓曲率特性的方法,记为APTD(Accumulation of Point to Tangent Distance)。使用高斯函数对轮廓曲线进行平滑处理,轮廓上点的曲率越大则该点附近的点到该点处切线的距离也越大,根据这一思想,将轮廓上点附近支撑域内的点到该点所对应切线相对距离的累加和作为拐点的判别函数,从而实现轮廓拐点的检测。经由数学推导表明所提出的算法具有合理性和可行性,对比实验分析表明该算法精度高、运算量小、定位准确。展开更多
A novel imidazole derivative with functional group and π-conjugated system, 1- [trans-4-（4-diethylaminostyryl）phenyl]imidazole （abbreviated as L）, and its Con complex （COCl2L4）2 （Co2C168H184N24Cl4, Mr = 2799....A novel imidazole derivative with functional group and π-conjugated system, 1- [trans-4-（4-diethylaminostyryl）phenyl]imidazole （abbreviated as L）, and its Con complex （COCl2L4）2 （Co2C168H184N24Cl4, Mr = 2799.05 ） have been synthesized and the crystal structure of the latter was determined by X-ray diffraction. The crystal is of triclinic, space group PI with a = 8.823（3）, b = 18.799（7）, c =23.065（9） A, α = 77.349（6）, β = 83.128（7）, ）, γ= 80.942（3）°, V = 3671.5（12） A^3, Z = 1, Dc = 1.266 g/cm^3,/z = 0.361 mm^-1 F（000） = 1482, the final R = 0.0587 and wR = 0.1284 for 6562 observed reflections with I 〉 2σ（I）. In the molecular structure of （COCl2L4）2, there are two crystallographically unique units. The Co^Ⅱ atoms are six-coordinated by four N atoms from four imidazole ligands （L） and two Cl atoms to form a distorted octahedral geometry. The optical properties of complex （COCl2L4）2 have been experimentally studied.展开更多
A novel bis（β-diketonate） derivate, 3,6-bis（4,4,4-trifluorobutane-1,3-dione）-9-n- butylcarbazole 1, was synthesized and structurally characterized by single-crystal X-ray diffrac- tion. The crystal belongs to the...A novel bis（β-diketonate） derivate, 3,6-bis（4,4,4-trifluorobutane-1,3-dione）-9-n- butylcarbazole 1, was synthesized and structurally characterized by single-crystal X-ray diffrac- tion. The crystal belongs to the monoclinic system, space group P2 1/c with a = 10.961（6）, b = 22.942（13）, c = 9.408（6）A, α = 90, β = 109.663（9）, y = 90°, V = 2228（2）A^3, Z = 4, Dc = 1.489 g/cm^3, C24H19F6NO4, Mr = 499.40, F（000） = 1024 and μ = 0.134 mm^-1. The structure was refined to the final R = 0.0699 and wR = 0.1627 for 3744 independent reflections （Rint = 0.1288） and 1349 observed reflections （I 〉 2σ（I））. Compound 1 consists of carbazole unit and two terminal diketonate groups, in which carbazole and its two adjacent diketonate rings are almost coplanar. Moreover, compound 1 was characterized with IR, elemental analysis, IH NMR, MS, electronic absorption, and single-photon fluorescence.展开更多
The title compound, trans 4 [p (N ethyl N (hydroxyethyl)amino) styryl] N methylpyridinium tetraphenylborate(abbreviated as ESMT, C 46 H 49 N 4OB) crystallizes in a space group P 1 with ...The title compound, trans 4 [p (N ethyl N (hydroxyethyl)amino) styryl] N methylpyridinium tetraphenylborate(abbreviated as ESMT, C 46 H 49 N 4OB) crystallizes in a space group P 1 with a =0 983 23(15) nm, b =1 410 73(16) nm, c =1 54 21(12) nm, α=95 252(13)°, β= 91 959(17)°, γ= 107 421(12)°, Z=2, F(000)=712, μ =0 1 mm -1 Mo Kα radiation, R =0 093 8. The result shows that the cation of the molecule almost lies in one plane, the hydroxyethyl group is perpendicular to the plane, the anion takes a slight distorted tetrahedral geometry. Also the thermal stability, two photon fluorescence, two photon pumped lasing property for the title compound were studied.展开更多
The syntheses and characterization of novel biferrocene trinuclear complexes of Schiff base ligand, S methyl N (ferrocenyl 1 methyl methylidene)dithiocarbazate [hereafter abbreviated as HL (1)], are described. The X r...The syntheses and characterization of novel biferrocene trinuclear complexes of Schiff base ligand, S methyl N (ferrocenyl 1 methyl methylidene)dithiocarbazate [hereafter abbreviated as HL (1)], are described. The X ray diffraction studies have established the structures of PdL 2 (3) and CuL 2 (4). The geometry of Pd(Ⅱ) in (3) is close to a square plane and in the novel cis configuration the two ferrocene moieties are in cis configuration, while that of Cu(Ⅱ) in (4) is close to a tetrahedral configuration. The electrochemical measurements suggested that the square planar configuration of Ni(Ⅱ) and Pd(Ⅱ) moieties can effectively transmit the redox effects of the ferrocene moieties, while the tetrahedral configuration of the Cu(Ⅱ) complex can not transmit the redox effects. The degenerate four wave mixing (DFWM) measurements showed that the complexes exhibit obviously nonlinear optical (NLO) response. The magnitude of their third order NLO susceptibility can be explained by their structure and electrochemical properties.展开更多
Crystal structure of the title compound, macrocyclic tetrabenzo(b ,f,J, n ) [ 1, 5, 9, 1 3] tetraazacyclohexadecine (TAAB ) N, N'-dimethyl formamide(DMF) ruthenium (Ⅱ) complex, [Ru (taab) (DMF )_2]·[ (ClO_4 ...Crystal structure of the title compound, macrocyclic tetrabenzo(b ,f,J, n ) [ 1, 5, 9, 1 3] tetraazacyclohexadecine (TAAB ) N, N'-dimethyl formamide(DMF) ruthenium (Ⅱ) complex, [Ru (taab) (DMF )_2]·[ (ClO_4 )_2](C_(34) H_(34)Cl)2N_6O_(10)Ru , M_r= 874. 66) is monoclinic with space group C2/c and a =36. 689(2) , b=18. 173 (8 ),. c= 10. 666(3)A, β=102. 6(4)°, V=6939. 6 A￣3 , D_c= 1. 67 gcm￣(-3), Z=8. The structural solutions and refinements based on 3183 reflections (I≥3σ(I)) converged at R= 0. 071 , R_w = 0. 074. The TAAB macrocyclic ligand has a saddle-shaped appearance,the ruthenium(Ⅱ) is located on the plane of the four nitrogen atoms of the TAAB with the two perpendicular Ru(Ⅱ)-O bonds coordinated to the DMF molecules.展开更多
The title compound biaquo (1.12-diaza-3, 4 : 9 . 10-dibenzos-5, 8-dioxacyclopentadecane-N-acetate) copper nitrate dihydrate. [Cu (C21H25O4N2) ( H2O)2].NO3·2H2O, Mr= 567. 05 . has been prepared. It crystallizes in...The title compound biaquo (1.12-diaza-3, 4 : 9 . 10-dibenzos-5, 8-dioxacyclopentadecane-N-acetate) copper nitrate dihydrate. [Cu (C21H25O4N2) ( H2O)2].NO3·2H2O, Mr= 567. 05 . has been prepared. It crystallizes in the monoclinic system. space group P21/a with a 12. 302(4) - b 13. 244(4), c= 15. 774(6)A . g=98. 59', V 2541 (l)\, Z 4. A(MoKα) = 0. 71069 A . D. l. 48 gcm-3. The structure was solved by direct methods with the final R 0. 060, R. 0. 081 for 3305observed reflections (I> 3a (I) ). The copper atom is surrounded by two nitrogen atoms and one oxygen atom from the carboxyl of the ligand and two oxygen atoms of coordinated water in a distorted square pyramidal arrangement. However, the two'ether oxygen atoms of the macrocyclic ligand are uncoordinated.展开更多
文摘拐点是图像很重要的特征,包含图像的主要结构信息,拐点检测对图像配准、目标识别和三维重建等任务的处理都有着非常重要的作用。从研究轮廓上点的曲率出发,针对传统基于轮廓的拐点检测算法对噪声和局部变化敏感而造成检测结果不稳定的问题,提出一种间接反映轮廓曲率特性的方法,记为APTD(Accumulation of Point to Tangent Distance)。使用高斯函数对轮廓曲线进行平滑处理,轮廓上点的曲率越大则该点附近的点到该点处切线的距离也越大,根据这一思想,将轮廓上点附近支撑域内的点到该点所对应切线相对距离的累加和作为拐点的判别函数,从而实现轮廓拐点的检测。经由数学推导表明所提出的算法具有合理性和可行性,对比实验分析表明该算法精度高、运算量小、定位准确。
基金This work was supported by the National Natural Science Foundation of China (50532030, 50335050, and 50325311) and Education Committee of Anhui Province (2006KJ158B)
文摘A novel imidazole derivative with functional group and π-conjugated system, 1- [trans-4-（4-diethylaminostyryl）phenyl]imidazole （abbreviated as L）, and its Con complex （COCl2L4）2 （Co2C168H184N24Cl4, Mr = 2799.05 ） have been synthesized and the crystal structure of the latter was determined by X-ray diffraction. The crystal is of triclinic, space group PI with a = 8.823（3）, b = 18.799（7）, c =23.065（9） A, α = 77.349（6）, β = 83.128（7）, ）, γ= 80.942（3）°, V = 3671.5（12） A^3, Z = 1, Dc = 1.266 g/cm^3,/z = 0.361 mm^-1 F（000） = 1482, the final R = 0.0587 and wR = 0.1284 for 6562 observed reflections with I 〉 2σ（I）. In the molecular structure of （COCl2L4）2, there are two crystallographically unique units. The Co^Ⅱ atoms are six-coordinated by four N atoms from four imidazole ligands （L） and two Cl atoms to form a distorted octahedral geometry. The optical properties of complex （COCl2L4）2 have been experimentally studied.
基金This work was supported by the National Natural Science Foundation of China (No. 50532030, 50325311, 50335050)Scientific Research & Development Foundation of Hefei University (No. 07KY003ZR)
文摘A novel bis（β-diketonate） derivate, 3,6-bis（4,4,4-trifluorobutane-1,3-dione）-9-n- butylcarbazole 1, was synthesized and structurally characterized by single-crystal X-ray diffrac- tion. The crystal belongs to the monoclinic system, space group P2 1/c with a = 10.961（6）, b = 22.942（13）, c = 9.408（6）A, α = 90, β = 109.663（9）, y = 90°, V = 2228（2）A^3, Z = 4, Dc = 1.489 g/cm^3, C24H19F6NO4, Mr = 499.40, F（000） = 1024 and μ = 0.134 mm^-1. The structure was refined to the final R = 0.0699 and wR = 0.1627 for 3744 independent reflections （Rint = 0.1288） and 1349 observed reflections （I 〉 2σ（I））. Compound 1 consists of carbazole unit and two terminal diketonate groups, in which carbazole and its two adjacent diketonate rings are almost coplanar. Moreover, compound 1 was characterized with IR, elemental analysis, IH NMR, MS, electronic absorption, and single-photon fluorescence.
文摘The title compound, trans 4 [p (N ethyl N (hydroxyethyl)amino) styryl] N methylpyridinium tetraphenylborate(abbreviated as ESMT, C 46 H 49 N 4OB) crystallizes in a space group P 1 with a =0 983 23(15) nm, b =1 410 73(16) nm, c =1 54 21(12) nm, α=95 252(13)°, β= 91 959(17)°, γ= 107 421(12)°, Z=2, F(000)=712, μ =0 1 mm -1 Mo Kα radiation, R =0 093 8. The result shows that the cation of the molecule almost lies in one plane, the hydroxyethyl group is perpendicular to the plane, the anion takes a slight distorted tetrahedral geometry. Also the thermal stability, two photon fluorescence, two photon pumped lasing property for the title compound were studied.
文摘The syntheses and characterization of novel biferrocene trinuclear complexes of Schiff base ligand, S methyl N (ferrocenyl 1 methyl methylidene)dithiocarbazate [hereafter abbreviated as HL (1)], are described. The X ray diffraction studies have established the structures of PdL 2 (3) and CuL 2 (4). The geometry of Pd(Ⅱ) in (3) is close to a square plane and in the novel cis configuration the two ferrocene moieties are in cis configuration, while that of Cu(Ⅱ) in (4) is close to a tetrahedral configuration. The electrochemical measurements suggested that the square planar configuration of Ni(Ⅱ) and Pd(Ⅱ) moieties can effectively transmit the redox effects of the ferrocene moieties, while the tetrahedral configuration of the Cu(Ⅱ) complex can not transmit the redox effects. The degenerate four wave mixing (DFWM) measurements showed that the complexes exhibit obviously nonlinear optical (NLO) response. The magnitude of their third order NLO susceptibility can be explained by their structure and electrochemical properties.
文摘Crystal structure of the title compound, macrocyclic tetrabenzo(b ,f,J, n ) [ 1, 5, 9, 1 3] tetraazacyclohexadecine (TAAB ) N, N'-dimethyl formamide(DMF) ruthenium (Ⅱ) complex, [Ru (taab) (DMF )_2]·[ (ClO_4 )_2](C_(34) H_(34)Cl)2N_6O_(10)Ru , M_r= 874. 66) is monoclinic with space group C2/c and a =36. 689(2) , b=18. 173 (8 ),. c= 10. 666(3)A, β=102. 6(4)°, V=6939. 6 A￣3 , D_c= 1. 67 gcm￣(-3), Z=8. The structural solutions and refinements based on 3183 reflections (I≥3σ(I)) converged at R= 0. 071 , R_w = 0. 074. The TAAB macrocyclic ligand has a saddle-shaped appearance,the ruthenium(Ⅱ) is located on the plane of the four nitrogen atoms of the TAAB with the two perpendicular Ru(Ⅱ)-O bonds coordinated to the DMF molecules.
文摘The title compound biaquo (1.12-diaza-3, 4 : 9 . 10-dibenzos-5, 8-dioxacyclopentadecane-N-acetate) copper nitrate dihydrate. [Cu (C21H25O4N2) ( H2O)2].NO3·2H2O, Mr= 567. 05 . has been prepared. It crystallizes in the monoclinic system. space group P21/a with a 12. 302(4) - b 13. 244(4), c= 15. 774(6)A . g=98. 59', V 2541 (l)\, Z 4. A(MoKα) = 0. 71069 A . D. l. 48 gcm-3. The structure was solved by direct methods with the final R 0. 060, R. 0. 081 for 3305observed reflections (I> 3a (I) ). The copper atom is surrounded by two nitrogen atoms and one oxygen atom from the carboxyl of the ligand and two oxygen atoms of coordinated water in a distorted square pyramidal arrangement. However, the two'ether oxygen atoms of the macrocyclic ligand are uncoordinated.
