One novel metal-organic framework [Cu2(L)(μ3-OH)]n(1, H3L = [1,1':3',1''-terphenyl]-4,4'',5'-tricarboxylic acid) has been synthesized and characterized by single-crystal powder X-ray diffraction, IR and...One novel metal-organic framework [Cu2(L)(μ3-OH)]n(1, H3L = [1,1':3',1''-terphenyl]-4,4'',5'-tricarboxylic acid) has been synthesized and characterized by single-crystal powder X-ray diffraction, IR and thermogravimetric analyses. Complex 1 crystallizes in orthorhombic crystal system, space group Pbca with a = 21.573(19), b = 5.404(5), c = 33.78(3) ?, C21H(12)O7Cu2, Mr = 503.39, V = 3938(6) A^3, Z = 8, Dc = 1.698 g·cm^-3, μ = 2.202 mm^-1, F(000) = 2016, 1.531〈θ〈25.009°, λ(Mo Kα) = 0.71073 A, T = 293(2) K, the final R = 0.0448 and wR = 0.1002. The structure of complex 1 is a three-dimensional(3D) framework based on infinite rod-shaped secondary building units and can be simplified as kgd topology. The gas adsorption measurements for N2, CO2, H2O, CH3OH and CH3CH2OH have been done. Fortunately, the selective sorption of CO2 over N2 was found at 195 K.展开更多
Magnetotactic bacteria are a group of Gram-negative bacteria that synthesize magnetic crystals, enabling them to navigate in relation to magnetic field lines. Morphologies of magnetotactic bacteria include spirillum, ...Magnetotactic bacteria are a group of Gram-negative bacteria that synthesize magnetic crystals, enabling them to navigate in relation to magnetic field lines. Morphologies of magnetotactic bacteria include spirillum, coccoid, rod, vibrio, and multicellular morphotypes. The coccid shape is generally the most abundant morphotype among magnetotactic bacteria. Here we describe a species of giant rod-shaped magnetotactic bacteria(designated QR-1) collected from sediment in the low tide zone of Huiquan Bay(Yellow Sea, China). This morphotype accounted for 90% of the magnetotactic bacteria collected, and the only taxonomic group which was detected in the sampling site. Microscopy analysis revealed that QR-1 cells averaged(6.71±1.03)×(1.54±0.20) m m in size, and contained in each cell 42–146 magnetosomes that are arranged in a bundle formed one to four chains along the long axis of the cell. The QR-1 cells displayed axial magnetotaxis with an average velocity of 70±28 mm/s. Transmission electron microscopy based analysis showed that QR-1 cells had two tufts of fl agella at each end. Phylogenetic analysis of the 16 S r RNA genes revealed that QR-1 together with three other rod-shaped uncultivated magnetotactic bacteria are clustered into a deep branch of A lphaproteobacteria.展开更多
A series of main chain liquid crystal aromatic copolyesters with X-shaped and rod-shaped mesogenic units were synthesized via solution condensation polymerizations of 4,4'-(alpha,omega-octanedioyloxy)-dibenzoyl di...A series of main chain liquid crystal aromatic copolyesters with X-shaped and rod-shaped mesogenic units were synthesized via solution condensation polymerizations of 4,4'-(alpha,omega-octanedioyloxy)-dibenzoyl dichlorides with 2,5-bis(p-octanoxy benzoyloxy)-hydroquinone and diphenol. All of the copolyesters showed thermotropic liquid crystalline behaviors through observations using DSC, polarized microscopy and X-ray diffraction. The melting point (T-m) and the isotropization temperature (T-i) change regularly with varying the content of diphenol unit in the copolymers.展开更多
By establishing the finite element models and corresponding calculation methods for the target board and rod-shaped fragment, the penetration effect of the high-velocity rod-shaped fragments' impact on the LY- 12cz t...By establishing the finite element models and corresponding calculation methods for the target board and rod-shaped fragment, the penetration effect of the high-velocity rod-shaped fragments' impact on the LY- 12cz thin sheet is analyzed by analog calculation. The variation rules of the residual velocity and residual mass of fragments, chock mass and crevasse shape are obtained when the fragment penetrates target board with different incidence velocities and attack angles. Corresponding fitting computation formulas are concluded from the above calculating data. The conclusions are helpful to analyzing the destructivity of fragment and protective ability of aircraft structure. In addition, they can guide the research for battle damage mode and assessment effectively.展开更多
The cross section of photonic crystal fiber (PCF) is a two dimensional photonic crystal. The rods formed in PCF are not exact cylinders, the shape of rods will affect the eigenmode formed in two dimensional photonic c...The cross section of photonic crystal fiber (PCF) is a two dimensional photonic crystal. The rods formed in PCF are not exact cylinders, the shape of rods will affect the eigenmode formed in two dimensional photonic crystals around a defect. Based on the relations between the defect eigenmodes and the radius of dielectric cylinders, the defect eigenmodes in photonic crystals in which the ellipse rods take the place of cylinders are studied by numerical calculation. The analysis of the relation between the eigenfrequency and the minor axis radius of ellipse rods show that the defect eigenfrequency is controlled by the cross section area of rods and the distribution of electromagnetic field around the defect is also affected by the cross section shape of rods. It provides a better way to modify the distribution of electromagnetic fields in photonic crystal and keeps the eigenfrequency unchanged.展开更多
The objective is to present exact analytical solutions of longitudinal impact analysis for slender conical rods struck by a particle and a new method is proposed for conical rod-particle impact analysis, in which the ...The objective is to present exact analytical solutions of longitudinal impact analysis for slender conical rods struck by a particle and a new method is proposed for conical rod-particle impact analysis, in which the superposition method is used and the response of the rod is presented. These analytical results are exact and can be used to validate the numerical methods or other analytical results. The numerical example shows that one of the advantages of the present method is that the analytical form is very simple. The result is that mass ratio and some variables describing the geometrical shape of rods such as taper, length and radius play an important role in impact dynamic system.展开更多
二硫化钨由于具有独特的层状结构、大的层间距等优点,已经成为一种非常有潜力的钠离子电池负极材料,但是其导电性差、充放电过程中易发生体积膨胀的不足限制了它进一步的广泛应用.本文以六氯化钨、硫代乙酰胺以及自制的空心碳壳为原料,...二硫化钨由于具有独特的层状结构、大的层间距等优点,已经成为一种非常有潜力的钠离子电池负极材料,但是其导电性差、充放电过程中易发生体积膨胀的不足限制了它进一步的广泛应用.本文以六氯化钨、硫代乙酰胺以及自制的空心碳壳为原料,采用溶剂热法合成了一种中空杆状结构的C/WS_(2)复合材料,将其用于钠离子电池来改善其上述存在的问题.结果表明,在2 A g^(-1)的电流密度下,循环90圈后,C/WS_(2)电极的比容量仍能达到417.1 mAh g^(-1);在10.0 A g^(-1)的大电流密度下,还具有343.3 mAh g^(^(-1))的比容量.因此,中空杆状C/WS2复合材料具有优异的储钠性能.展开更多
基金Supported by the Natural Science Foundation of Shandong Province(No.ZR2016BL01)the Talent Introduction Project of Dezhou University(No.320116)
文摘One novel metal-organic framework [Cu2(L)(μ3-OH)]n(1, H3L = [1,1':3',1''-terphenyl]-4,4'',5'-tricarboxylic acid) has been synthesized and characterized by single-crystal powder X-ray diffraction, IR and thermogravimetric analyses. Complex 1 crystallizes in orthorhombic crystal system, space group Pbca with a = 21.573(19), b = 5.404(5), c = 33.78(3) ?, C21H(12)O7Cu2, Mr = 503.39, V = 3938(6) A^3, Z = 8, Dc = 1.698 g·cm^-3, μ = 2.202 mm^-1, F(000) = 2016, 1.531〈θ〈25.009°, λ(Mo Kα) = 0.71073 A, T = 293(2) K, the final R = 0.0448 and wR = 0.1002. The structure of complex 1 is a three-dimensional(3D) framework based on infinite rod-shaped secondary building units and can be simplified as kgd topology. The gas adsorption measurements for N2, CO2, H2O, CH3OH and CH3CH2OH have been done. Fortunately, the selective sorption of CO2 over N2 was found at 195 K.
基金Supported by the National Natural Science Foundation of China(Nos.41330962,41276170)the National Natural Science Foundation of China-Shandong Joint Fund for Marine Science Research Centers(No.U1606404)
文摘Magnetotactic bacteria are a group of Gram-negative bacteria that synthesize magnetic crystals, enabling them to navigate in relation to magnetic field lines. Morphologies of magnetotactic bacteria include spirillum, coccoid, rod, vibrio, and multicellular morphotypes. The coccid shape is generally the most abundant morphotype among magnetotactic bacteria. Here we describe a species of giant rod-shaped magnetotactic bacteria(designated QR-1) collected from sediment in the low tide zone of Huiquan Bay(Yellow Sea, China). This morphotype accounted for 90% of the magnetotactic bacteria collected, and the only taxonomic group which was detected in the sampling site. Microscopy analysis revealed that QR-1 cells averaged(6.71±1.03)×(1.54±0.20) m m in size, and contained in each cell 42–146 magnetosomes that are arranged in a bundle formed one to four chains along the long axis of the cell. The QR-1 cells displayed axial magnetotaxis with an average velocity of 70±28 mm/s. Transmission electron microscopy based analysis showed that QR-1 cells had two tufts of fl agella at each end. Phylogenetic analysis of the 16 S r RNA genes revealed that QR-1 together with three other rod-shaped uncultivated magnetotactic bacteria are clustered into a deep branch of A lphaproteobacteria.
基金The work was supported by the National Natural Science Foundation of China.
文摘A series of main chain liquid crystal aromatic copolyesters with X-shaped and rod-shaped mesogenic units were synthesized via solution condensation polymerizations of 4,4'-(alpha,omega-octanedioyloxy)-dibenzoyl dichlorides with 2,5-bis(p-octanoxy benzoyloxy)-hydroquinone and diphenol. All of the copolyesters showed thermotropic liquid crystalline behaviors through observations using DSC, polarized microscopy and X-ray diffraction. The melting point (T-m) and the isotropization temperature (T-i) change regularly with varying the content of diphenol unit in the copolymers.
基金Sponsored by the Ministerial Level Advanced Research Foundation(2164K)
文摘By establishing the finite element models and corresponding calculation methods for the target board and rod-shaped fragment, the penetration effect of the high-velocity rod-shaped fragments' impact on the LY- 12cz thin sheet is analyzed by analog calculation. The variation rules of the residual velocity and residual mass of fragments, chock mass and crevasse shape are obtained when the fragment penetrates target board with different incidence velocities and attack angles. Corresponding fitting computation formulas are concluded from the above calculating data. The conclusions are helpful to analyzing the destructivity of fragment and protective ability of aircraft structure. In addition, they can guide the research for battle damage mode and assessment effectively.
文摘The cross section of photonic crystal fiber (PCF) is a two dimensional photonic crystal. The rods formed in PCF are not exact cylinders, the shape of rods will affect the eigenmode formed in two dimensional photonic crystals around a defect. Based on the relations between the defect eigenmodes and the radius of dielectric cylinders, the defect eigenmodes in photonic crystals in which the ellipse rods take the place of cylinders are studied by numerical calculation. The analysis of the relation between the eigenfrequency and the minor axis radius of ellipse rods show that the defect eigenfrequency is controlled by the cross section area of rods and the distribution of electromagnetic field around the defect is also affected by the cross section shape of rods. It provides a better way to modify the distribution of electromagnetic fields in photonic crystal and keeps the eigenfrequency unchanged.
基金Project supported by the National Natural Science Foundation of China (Nos. 10372084 and 10572119) Program for New Century Excellent Talents of Education Ministry of China (No.NCET-04-0958) and the Open Foundation of State Key Laboratory of Structural Analysis of Industrial Equipment
文摘The objective is to present exact analytical solutions of longitudinal impact analysis for slender conical rods struck by a particle and a new method is proposed for conical rod-particle impact analysis, in which the superposition method is used and the response of the rod is presented. These analytical results are exact and can be used to validate the numerical methods or other analytical results. The numerical example shows that one of the advantages of the present method is that the analytical form is very simple. The result is that mass ratio and some variables describing the geometrical shape of rods such as taper, length and radius play an important role in impact dynamic system.
文摘二硫化钨由于具有独特的层状结构、大的层间距等优点,已经成为一种非常有潜力的钠离子电池负极材料,但是其导电性差、充放电过程中易发生体积膨胀的不足限制了它进一步的广泛应用.本文以六氯化钨、硫代乙酰胺以及自制的空心碳壳为原料,采用溶剂热法合成了一种中空杆状结构的C/WS_(2)复合材料,将其用于钠离子电池来改善其上述存在的问题.结果表明,在2 A g^(-1)的电流密度下,循环90圈后,C/WS_(2)电极的比容量仍能达到417.1 mAh g^(-1);在10.0 A g^(-1)的大电流密度下,还具有343.3 mAh g^(^(-1))的比容量.因此,中空杆状C/WS2复合材料具有优异的储钠性能.