A noncrystallizable semiaromatic polyamide copolymer(NSAP) was dissolved in molten caprolactam, and PA6/ NSAP blends were produced in-situ via the anionic ring-opening polymerization of caprolactam. The presence of ...A noncrystallizable semiaromatic polyamide copolymer(NSAP) was dissolved in molten caprolactam, and PA6/ NSAP blends were produced in-situ via the anionic ring-opening polymerization of caprolactam. The presence of a single loss tangent(tanS) peak measured by means of dynamic mechanical analysis(DMA) proves the miscibility between PA6 and NSAP in the blends. It was found that there existed drastic changes in the crystallographic form and crystallization kinetics for the in-situ blends, e.g. , when 20% NSAP was added, nearly all crystallites existed in the ,y form and the crystallization could hardly occur upon cooling even at a rate of 2.5 ℃/min. Moreover, cold crystallization appears during the subsequent heating, and its melting point is 40 ℃ lower than that of the virgin system. On the other hand, the size of the spherulites only decreases modestly. It is suggested that the introduction of irregular stiff segments originated from NSAP into PA6 macromolecule chain, which resulted from transamidation during the polymerization play a dominant role in the drastic change of crystallization kinetics and the resultant morphology of the in-situ blends.展开更多
Crystallization behavior and kinetics study of palm kernel oil (PKO) were investigated using differential scanning calorimetry (DSC) by controlling cooling and reheating rate within a certain range of temperature. The...Crystallization behavior and kinetics study of palm kernel oil (PKO) were investigated using differential scanning calorimetry (DSC) by controlling cooling and reheating rate within a certain range of temperature. The evolution of morphology and particle counts was analyzed by focused beam reflectance measurement (FBRM) and particles video microscope (PVM) at the nucleation stage during suspension crystallization. The particle counts and morphological evolution from needle-like aggregations to amorphous form from PVM were observed during the initial crystallization stage, which meant that a phase transition was likely to occur. This work can give a better understanding of complicated fat system crystallization behavior and provide some critical instructions to control fractionation process.展开更多
It is clarified by experimental examination and theoretical analysis that the transformation of crystal moorphology of the eutectic Al-Cu alloy composite-in-situ seems to be judged by not only the constitutional super...It is clarified by experimental examination and theoretical analysis that the transformation of crystal moorphology of the eutectic Al-Cu alloy composite-in-situ seems to be judged by not only the constitutional supercooling proposed in previous literatures but also the supercooling due to the effect of curved surfaces at the solidifying from.The greater entropy of fusion and the tendency to faceted face are important features of the non-metallic phase,which may con- tribute to the leading,role of the phase during solidification.It might be the change of leading phase that changes the morphology of crystals.展开更多
Using the langasite crystal microbalance (LCM), the trends in film thickness produced by means of the chemical vapor deposition using trichlorosilane gas, monomethylsilane gas and their mixed gas were observed at 600?...Using the langasite crystal microbalance (LCM), the trends in film thickness produced by means of the chemical vapor deposition using trichlorosilane gas, monomethylsilane gas and their mixed gas were observed at 600?C and evaluated by comparison with the information from a transmission electron microscope (TEM). The crystalline silicon film thickness from trichlorosilane gas was comparable to that of an amorphous silicon carbide film from monomethylsilane gas. The film obtained from the gas mixture was amorphous and was the thinnest in this study. Because the thickness trend obtained by the LCM agreed with that by the TEM, the LCM is shown to be a convenient evaluation tool for the behavior of various film deposition.展开更多
Hydrothermal reactions of 3-cyanopyridine and Na N3 with Zn Cl_2 or Cd Cl_2·5/2H_2 O in the presence of 1,4-benzenedicarboxylic acid(H2bdc) yielded two new coordination polymers,{[Zn(3-ptz)(bdc)_(0.5)(H...Hydrothermal reactions of 3-cyanopyridine and Na N3 with Zn Cl_2 or Cd Cl_2·5/2H_2 O in the presence of 1,4-benzenedicarboxylic acid(H2bdc) yielded two new coordination polymers,{[Zn(3-ptz)(bdc)_(0.5)(H_2O)_2]n·2H_2O}_n(1) and [Cd_2(3-ptz)_2Cl_2]_n(2),based on in situ synthesized 5-(3-pyridyl)tetrazolate(3-ptz-) organic ligand.They have been structurally characterized by elemental analysis(EA),infrared spectroscopy(IR) and single-crystal/powder X-ray diffraction(PXRD).In 1,two Zn(Ⅱ) ions are linked together through two μ_2-(3-ptz-) ligands to form a dimeric unit of [Zn(μ_2-3-ptz)(H_2O)_2]2^2+,which is further connected with other equivalent units by μ_2-bdc^2-spacers,resulting in an infinite 1D polymeric chain of [Zn_2(3-ptz)_2(H_2O)_2(bdc)]_n,and then strong hydrogen bonding interactions extend these 1D chains into a 3D supramolecular structure.In 2,the Cd(Ⅱ) ions are connected through μ_4-(3-ptz-) ligands and Cl-anions,leading to infinite 2D layers of [Cd_2(3-ptz)Cl_2]_n^n+,which are further linked by another μ_4-(3-ptz-) pillared ligand to form a 3D layered-pillared framework architecture of [Cd)2(3-ptz))2Cl)2])n.Furthermore,thermal stability of these compounds was measured by thermogravimetric analysis(TGA) and their photoluminescent properties were also investigated in the solid state at room temperature.展开更多
Electrochemical quartz crystal impedance system (EQCIS) which allows in situ dynamic quartz crystal impedance measurement in an electrochemical experiment was developed by combining an HP 4395A Network/Spectrum/Impeda...Electrochemical quartz crystal impedance system (EQCIS) which allows in situ dynamic quartz crystal impedance measurement in an electrochemical experiment was developed by combining an HP 4395A Network/Spectrum/Impedance analyzer with an EG&G M283 potentiostat. Equivalent circuit parameters of crystal resonance change significantly during electrodeposition and dissolution of copper in 0.1 mol/L H2SO4 aqueous solution in a cyclic potential sweep experiment, which is explained with an overall picture of mass loading, solution density and viscosity, etc..展开更多
In this paper, the elastic wave propagation in a two-dimensional piezoelectric phononic crystal is studied by considering the mechanic-electric coupling. The generalized eigenvalue equation is obtained by the relation...In this paper, the elastic wave propagation in a two-dimensional piezoelectric phononic crystal is studied by considering the mechanic-electric coupling. The generalized eigenvalue equation is obtained by the relation of the mechanic and electric fields as well as the Bloch-Floquet theorem. The band structures of both the in-plane and anti-plane modes are calculated for a rectangular lattice by the planewave expansion method. The effects of the lattice constant ratio and the piezoelectricity with different filling fractions are analyzed. The results show that the largest gap width is not always obtained for a square lattice. In some situations, a rectangular lattice may generate larger gaps. The band gap characteristics are influenced obviously by the piezoelectricity with the larger lattice constant ratios and the filling fractions.展开更多
A new Cu(Ⅰ) coordination polymer(CP) formulated as [Cu2(L)(CN)2]n(1, L =1,1′-bis(5,6-dimethylbenzimidazole)methane) was synthesized, in which the cyanide anions were generated in situ by the cleavage of C–C bond of...A new Cu(Ⅰ) coordination polymer(CP) formulated as [Cu2(L)(CN)2]n(1, L =1,1′-bis(5,6-dimethylbenzimidazole)methane) was synthesized, in which the cyanide anions were generated in situ by the cleavage of C–C bond of acetonitrile under hydrothermal conditions. CP 1 was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. It crystallizes in the orthorhombic system, Pccn space group, with a = 10.314(3), b = 20.966(7), c =9.432(3)?, V = 2039.5(11)?3, Z = 4, C21 H20 Cu2 N6, Mr = 483.51, Dc = 1.575 g×cm^-3,μ= 2.105 mm-1 and F(000)= 984, the final R = 0.0608 and wR = 0.1942 for 1226 observed reflections with Ⅰ> 2s(Ⅰ)for the CP 1. The CP 1 possesses a 2D {63} layer structure which is composed of Cu(Ⅰ) centers bridged by L and CN– ligands. The thermal stability and luminescence properties of CP 1 are discussed in detail. The complex also displays a remarkable activity for the degradation of methyl orange by hydrogen peroxide in a Fenton-like process.展开更多
Chromosome aberrations are distinctive features of human malignant tumors. Analysis of chromosomal changes can illuminate the molecular mechanisms underlying the development and progression of cancer. To establish the...Chromosome aberrations are distinctive features of human malignant tumors. Analysis of chromosomal changes can illuminate the molecular mechanisms underlying the development and progression of cancer. To establish the technique of multicolor fluorescence in situ hybridization (M-FISH) for identifying chromosome aberrations in esophageal carcinoma cell line KYSE 410-4, four pools of 6-color whole-chromosome painting probes have been designed and hybridized on the same metaphase spread by four rounds of repetitive FISH. Repetitive 6-color M-FISH was successfully established and the cytogenetic abnormalities in KYSE 410-4 cells were characterized. Chromosome gains occurred at 2q, 3, 8, 17p, and X. An isochromosome 3q was visualized in the cell line, which might be one intermediate mechanism leading to 3p losses and/or 3q gains. Furthermore, 16 structural arrangements were detected, including four derivative chromosomes. The rearrangement of the centromeric regions accounted for approximately 44% of all rearrangements. The results added a more complete and accurate information of the genetic alterations to the classical cytogenetic description of KYSE 410-4 and provided a detailed cytogenetic background data for appropriate use of the cell line. The established 6-color M-FISH was useful for analyzing chromosomes in the whole genome of human tumors.展开更多
The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at ...The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at 160 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectrum. The new ligand 4-hydroxyl-5-sulfoisophthalic acid derived from 5-sulfoisophthalic acid ligand under an in situ hydrothermal condition. The crystal of the complex crystallizes in a triclinic system, space group P1, with a = 7.757(4), b = 10.663(6), c = 11.727(7)A, α = 94.272(4), β = 104.067(7), γ = 97.400(7)°, V= 927.4(9)A^3, Z = 2, C18H14N2O9SCu, Mr= 497.93, Dc= 1.783 g/cm^3,μ = 1.350 mm^-1, F(000) = 506, the final R = 0.0518 and wR = 0.1513 for 4180 observed reflections with I 〉 2σ(I). The central Cu(II) ion is five-coordinated by two oxygen atoms from the H2SIP-O^2- ligand and two nitrogen atoms of bpy ligand in a distorted square-planar geometry as well as a water oxygen atom in the apical position to complete a distorted square-pyramidal coordination geometry. The mononuclear copper molecules are linked by hydrogen bonds between coordinated water molecules and sulfonate groups to form a one-dimensional double-chain structure. The chains are further held together through extensive π-π stacking interactions between the aromatic rings to form a three- dimensional supramolecular structure.展开更多
The growth mechanism of reinforcement in in situ synthesized (TiB+TiC)/Ti composites was investigated. The results show that reinforcements nucleate and grow in a way of dissolution precipitation. The morphologies of ...The growth mechanism of reinforcement in in situ synthesized (TiB+TiC)/Ti composites was investigated. The results show that reinforcements nucleate and grow in a way of dissolution precipitation. The morphologies of reinforcements are closely related to the solidification paths and crystal structure of reinforcements. TiB, as a reinforcement, is liable to grow along [010] direction and forms in short fibre shape due to its B27 structure, whereas primary TiC is liable to form composition undercooling and grow in dendritic shape. TiC phases precipitated in binary eutectic and ternary eutectic reactions grow in equiaxial shape. The addition of aluminum element refines TiB and TiC particles, and makes TiC reinforcements grow into the equiaxial particles easily. The addition of graphite adjusts the solidification paths and forms more TiC with dendritic shape. [展开更多
A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic ...A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.展开更多
A new coordination compound Zn(2,4'-bpt)2(H2O)(1) based on the versatile ligand 2,4'-Hbpt(2,4?-Hbpt = 3-(2-pyridyl)-5-(4-pyridyl)-1H-1,2,4-triazole) was prepared by hydrothermal reactions. The structure...A new coordination compound Zn(2,4'-bpt)2(H2O)(1) based on the versatile ligand 2,4'-Hbpt(2,4?-Hbpt = 3-(2-pyridyl)-5-(4-pyridyl)-1H-1,2,4-triazole) was prepared by hydrothermal reactions. The structure of complex 1 has been characterized by X-ray single-crystal diffraction, elemental analysis, X-ray powder diffraction, IR spectrum analysis and thermogravimetric analysis. Single-crystal X-ray diffraction analysis indicates that the complex belongs to monoclinic system, space group C2/c with a = 23.877(3), b = 0.7483(9), c = 1.2492(2) A, b = 92.681(2)°, V = 2230.6(4) A^3, Z = 4, Dc = 1.572 g/cm^3, m = 1.143 mm^-1, Mr = 527.85 and F(000) = 1080. The final R = 0.0581 and wR = 0.0898 with I 〉 2s(I). 1 is a 0D motif which is connected by hydrogen bonds to form a corrugated 1D pattern. In addition, 1 shows strong photoluminescent emissions in the solid state at room temperature which can be used as potential optical materials. Theoretical calculations based on density functional theory(DFT) were employed in order to explicate the stability and chemical reactivity of 2,4'-Hbpt with different conformations. The results indicated that conformation I is more stable and prior to coordination in the reactions.展开更多
A new Cu(Ⅱ) complex [Cu(4-cba)(1,10-phen)(H2O)2](NO3) (4-Hcba = 4-cyanobenzoic acid) has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characteriz...A new Cu(Ⅱ) complex [Cu(4-cba)(1,10-phen)(H2O)2](NO3) (4-Hcba = 4-cyanobenzoic acid) has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data: C20H16CuN4O7, Mr= 487.91, triclinic, space group PI, a = 7.8420(2), b = 9.1070(2), c = 15.1140(6) A, a = 76.889(9), β = 81.332(11), γ = 74.844( 11)°, V = 1009.89(5) A^3, Z = 2, Dc = 1.605 g/cm^3, F(000) = 498, μ = 1.134 mm^-1, the final R = 0.0379 and wR = 0.0865 for 2977 observed reflections with 1 〉 2σ(Ⅰ). The Cu(Ⅱ) atom is coordinated by two terminal water molecules, one chelating 1,10-phen molecule and one monodentate 4-cba ligand to form a slightly distorted square pyramid. The title complex molecules are connected through hydrogen bonds and π-π stacking interactions to generate a 2D layered network. The thermogravimetric analysis of the title complex has also been discussed.展开更多
A new Cu(Ⅱ) coordination polymer, [Cu(L1)(L2)](1), was synthesized under hydrothermal conditions(H_2L1 = 4-(carboxymethoxy)benzoic acid, L2 = 2-(4-fluorophenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Crystallograph...A new Cu(Ⅱ) coordination polymer, [Cu(L1)(L2)](1), was synthesized under hydrothermal conditions(H_2L1 = 4-(carboxymethoxy)benzoic acid, L2 = 2-(4-fluorophenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Crystallographic data for 1: triclinic, space group P1 with a = 9.750(5), b = 10.148(5), c = 12.869(5) ?, α = 104.904(5), β = 102.133(5), γ = 95.219(5)°, V = 1188.7(10) ?~3, Z = 2, C_(28)H_(17)FN_4O_5Cu, Mr = 572.01, D_c = 1.598 g/cm^3, F(000) = 582, μ(MoKa) = 0.977 mm^(-1), R = 0.0474 and w R = 0.1144. The TGA behaviors and luminescence of 1 have been studied in detail. The L1 dianions link neighboring Cu(Ⅱ) atoms in a bis-chelating mode, yielding a one-dimensional chain structure along the b axis. The L2 ligands are attached on one side of the chain through chelating the Cu(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. Additionally, the N–H???O hydrogen bonds further stabilize the structure of 1.展开更多
A new Zn(II) complex, [Zn(L)(IPP)(H2O)]'2H2O(1, H2L = 3-carboxy-l-car- boxymethyl-2-oxidopyridinium and IPP = 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol), was synthesized under hydrothermal condi...A new Zn(II) complex, [Zn(L)(IPP)(H2O)]'2H2O(1, H2L = 3-carboxy-l-car- boxymethyl-2-oxidopyridinium and IPP = 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol), was synthesized under hydrothermal conditions and its structure was determined by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pi with a = 8.5023(17), b = 9.945(2), c = 15.573(3) A, a = 95.87(3), β = 102.56(3), y = 100.73(3)°, V= 1248.7(4) A3, Z= 2, C27H22N5O9Zn, Mr= 625.87, Dc = 1.665 g/cm^3, F(000) = 642, μ(MoKa) = 1.053 mm^-1, R = 0.0474 and wR = 0.1352. In 1, one L2-, one 1PP and one water molecule coordinate to the same Zn(II) atom to give a discrete complex with two lattice water molecules. Adjacent [Zn(L)(IPP)(H20)].2H20 molecules interact through π-π stacking between two IPP ligands to form a supramolecular chain. The N-H…O and O-H…N hydrogen bonds further stabilize the supramolecular chain structure of 1. The solid state luminescent property of 1 was also studied.展开更多
The title compound (E)-4-tert-butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine was synthesized by the reaction of 4-tert-butyl-5-(1,2,4-triazol-1-yl)-thiazol-2-amine with 2,4-dichlorobe...The title compound (E)-4-tert-butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine was synthesized by the reaction of 4-tert-butyl-5-(1,2,4-triazol-1-yl)-thiazol-2-amine with 2,4-dichlorobenzaldehyde, and its crystal structure was determined by singlecrystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.9748(4), b = 10.1803(5), c = 11.4603(6), α = 102.882(1), β = 100.253(1), γ = 104.457(1)°, V = 850.95(7)3, Z = 2, F(000) = 392, C16H15Cl2N5S, Mr = 380.29, Dc = 1.484 g/cm3, S = 1.095, μ = 0.512 mm-1, the final R = 0.0301 and wR = 0.0965 for 3334 observed reflections (I 〉 2σ(I)). The preliminary antitumor activity shows that for the title compound the IC50 of Hela is 0.175 μmol/mL and that of Bel7402 is 0.156 μmol/mL.展开更多
Two new Cd(Ⅱ) coordination polymers, [Cd(PT)(1,4-BDC)0.5]n (1) and [Cd(PT) (1,3-BDC)0.5]n (2) (HPT = 3-(pyridin-2-yl)-1,2,4-triazole, 1,4-H2BDC = 1,4-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzene...Two new Cd(Ⅱ) coordination polymers, [Cd(PT)(1,4-BDC)0.5]n (1) and [Cd(PT) (1,3-BDC)0.5]n (2) (HPT = 3-(pyridin-2-yl)-1,2,4-triazole, 1,4-H2BDC = 1,4-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. Complexes 1 and 2 are both three-dimensional coordination polymers with two-dimensional sheet structures bridged by the deprotonated carboxylate ligands. In 1, 1,4-BDC2- bridges the layered network to generate a quadrangular framework, and 2 owns a sexangular framework, which was caused by the different steric hindrance between 1,4-BDC^2- and 1,3-BDC^2-. Their thermal stabilities and photoluminescent properties have been also investigated.展开更多
基金Supported by the National Natural Science Foundation of China(No50373037)
文摘A noncrystallizable semiaromatic polyamide copolymer(NSAP) was dissolved in molten caprolactam, and PA6/ NSAP blends were produced in-situ via the anionic ring-opening polymerization of caprolactam. The presence of a single loss tangent(tanS) peak measured by means of dynamic mechanical analysis(DMA) proves the miscibility between PA6 and NSAP in the blends. It was found that there existed drastic changes in the crystallographic form and crystallization kinetics for the in-situ blends, e.g. , when 20% NSAP was added, nearly all crystallites existed in the ,y form and the crystallization could hardly occur upon cooling even at a rate of 2.5 ℃/min. Moreover, cold crystallization appears during the subsequent heating, and its melting point is 40 ℃ lower than that of the virgin system. On the other hand, the size of the spherulites only decreases modestly. It is suggested that the introduction of irregular stiff segments originated from NSAP into PA6 macromolecule chain, which resulted from transamidation during the polymerization play a dominant role in the drastic change of crystallization kinetics and the resultant morphology of the in-situ blends.
文摘Crystallization behavior and kinetics study of palm kernel oil (PKO) were investigated using differential scanning calorimetry (DSC) by controlling cooling and reheating rate within a certain range of temperature. The evolution of morphology and particle counts was analyzed by focused beam reflectance measurement (FBRM) and particles video microscope (PVM) at the nucleation stage during suspension crystallization. The particle counts and morphological evolution from needle-like aggregations to amorphous form from PVM were observed during the initial crystallization stage, which meant that a phase transition was likely to occur. This work can give a better understanding of complicated fat system crystallization behavior and provide some critical instructions to control fractionation process.
文摘It is clarified by experimental examination and theoretical analysis that the transformation of crystal moorphology of the eutectic Al-Cu alloy composite-in-situ seems to be judged by not only the constitutional supercooling proposed in previous literatures but also the supercooling due to the effect of curved surfaces at the solidifying from.The greater entropy of fusion and the tendency to faceted face are important features of the non-metallic phase,which may con- tribute to the leading,role of the phase during solidification.It might be the change of leading phase that changes the morphology of crystals.
文摘Using the langasite crystal microbalance (LCM), the trends in film thickness produced by means of the chemical vapor deposition using trichlorosilane gas, monomethylsilane gas and their mixed gas were observed at 600?C and evaluated by comparison with the information from a transmission electron microscope (TEM). The crystalline silicon film thickness from trichlorosilane gas was comparable to that of an amorphous silicon carbide film from monomethylsilane gas. The film obtained from the gas mixture was amorphous and was the thinnest in this study. Because the thickness trend obtained by the LCM agreed with that by the TEM, the LCM is shown to be a convenient evaluation tool for the behavior of various film deposition.
基金supported by the National Natural Science Foundation of China(No.21071099)Natural Science Foundation of Guangdong Province(No.2015A030313750)Characteristic Innovation Projects Guangdong Provincial Department of Education(Natural Science Category,2014KTSCX169)
文摘Hydrothermal reactions of 3-cyanopyridine and Na N3 with Zn Cl_2 or Cd Cl_2·5/2H_2 O in the presence of 1,4-benzenedicarboxylic acid(H2bdc) yielded two new coordination polymers,{[Zn(3-ptz)(bdc)_(0.5)(H_2O)_2]n·2H_2O}_n(1) and [Cd_2(3-ptz)_2Cl_2]_n(2),based on in situ synthesized 5-(3-pyridyl)tetrazolate(3-ptz-) organic ligand.They have been structurally characterized by elemental analysis(EA),infrared spectroscopy(IR) and single-crystal/powder X-ray diffraction(PXRD).In 1,two Zn(Ⅱ) ions are linked together through two μ_2-(3-ptz-) ligands to form a dimeric unit of [Zn(μ_2-3-ptz)(H_2O)_2]2^2+,which is further connected with other equivalent units by μ_2-bdc^2-spacers,resulting in an infinite 1D polymeric chain of [Zn_2(3-ptz)_2(H_2O)_2(bdc)]_n,and then strong hydrogen bonding interactions extend these 1D chains into a 3D supramolecular structure.In 2,the Cd(Ⅱ) ions are connected through μ_4-(3-ptz-) ligands and Cl-anions,leading to infinite 2D layers of [Cd_2(3-ptz)Cl_2]_n^n+,which are further linked by another μ_4-(3-ptz-) pillared ligand to form a 3D layered-pillared framework architecture of [Cd)2(3-ptz))2Cl)2])n.Furthermore,thermal stability of these compounds was measured by thermogravimetric analysis(TGA) and their photoluminescent properties were also investigated in the solid state at room temperature.
文摘Electrochemical quartz crystal impedance system (EQCIS) which allows in situ dynamic quartz crystal impedance measurement in an electrochemical experiment was developed by combining an HP 4395A Network/Spectrum/Impedance analyzer with an EG&G M283 potentiostat. Equivalent circuit parameters of crystal resonance change significantly during electrodeposition and dissolution of copper in 0.1 mol/L H2SO4 aqueous solution in a cyclic potential sweep experiment, which is explained with an overall picture of mass loading, solution density and viscosity, etc..
基金the National Natural Science Foundation of China (10672017 and 10632020)
文摘In this paper, the elastic wave propagation in a two-dimensional piezoelectric phononic crystal is studied by considering the mechanic-electric coupling. The generalized eigenvalue equation is obtained by the relation of the mechanic and electric fields as well as the Bloch-Floquet theorem. The band structures of both the in-plane and anti-plane modes are calculated for a rectangular lattice by the planewave expansion method. The effects of the lattice constant ratio and the piezoelectricity with different filling fractions are analyzed. The results show that the largest gap width is not always obtained for a square lattice. In some situations, a rectangular lattice may generate larger gaps. The band gap characteristics are influenced obviously by the piezoelectricity with the larger lattice constant ratios and the filling fractions.
基金Supported by the National Natural Science Foundation of China(No.51474086)
文摘A new Cu(Ⅰ) coordination polymer(CP) formulated as [Cu2(L)(CN)2]n(1, L =1,1′-bis(5,6-dimethylbenzimidazole)methane) was synthesized, in which the cyanide anions were generated in situ by the cleavage of C–C bond of acetonitrile under hydrothermal conditions. CP 1 was characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction. It crystallizes in the orthorhombic system, Pccn space group, with a = 10.314(3), b = 20.966(7), c =9.432(3)?, V = 2039.5(11)?3, Z = 4, C21 H20 Cu2 N6, Mr = 483.51, Dc = 1.575 g×cm^-3,μ= 2.105 mm-1 and F(000)= 984, the final R = 0.0608 and wR = 0.1942 for 1226 observed reflections with Ⅰ> 2s(Ⅰ)for the CP 1. The CP 1 possesses a 2D {63} layer structure which is composed of Cu(Ⅰ) centers bridged by L and CN– ligands. The thermal stability and luminescence properties of CP 1 are discussed in detail. The complex also displays a remarkable activity for the degradation of methyl orange by hydrogen peroxide in a Fenton-like process.
基金Acknowledgements This study was supported by the National Science Foundation (No. 30630067);the State Key Basic Research Grant of China (No. 2004CB518705); the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0416).
文摘Chromosome aberrations are distinctive features of human malignant tumors. Analysis of chromosomal changes can illuminate the molecular mechanisms underlying the development and progression of cancer. To establish the technique of multicolor fluorescence in situ hybridization (M-FISH) for identifying chromosome aberrations in esophageal carcinoma cell line KYSE 410-4, four pools of 6-color whole-chromosome painting probes have been designed and hybridized on the same metaphase spread by four rounds of repetitive FISH. Repetitive 6-color M-FISH was successfully established and the cytogenetic abnormalities in KYSE 410-4 cells were characterized. Chromosome gains occurred at 2q, 3, 8, 17p, and X. An isochromosome 3q was visualized in the cell line, which might be one intermediate mechanism leading to 3p losses and/or 3q gains. Furthermore, 16 structural arrangements were detected, including four derivative chromosomes. The rearrangement of the centromeric regions accounted for approximately 44% of all rearrangements. The results added a more complete and accurate information of the genetic alterations to the classical cytogenetic description of KYSE 410-4 and provided a detailed cytogenetic background data for appropriate use of the cell line. The established 6-color M-FISH was useful for analyzing chromosomes in the whole genome of human tumors.
基金Supported by the Education Department of Jiangxi Province (No 2007-125)the Initial Fund for Doctors from Jiangxi Normal University
文摘The mononuclear complex, Cu(H2SIP-O)(bpy)(H2O) (H4SIP-O = 4-hydroxyl- 5-sulfoisophthalic acid and bpy = 2,2'-dipyridyl), has been synthesized by the hydrothermal reaction of Cu(OH)2 with NaH2SIP and bpy at 160 ℃, and characterized by single-crystal X-ray diffraction, elemental analysis and IR spectrum. The new ligand 4-hydroxyl-5-sulfoisophthalic acid derived from 5-sulfoisophthalic acid ligand under an in situ hydrothermal condition. The crystal of the complex crystallizes in a triclinic system, space group P1, with a = 7.757(4), b = 10.663(6), c = 11.727(7)A, α = 94.272(4), β = 104.067(7), γ = 97.400(7)°, V= 927.4(9)A^3, Z = 2, C18H14N2O9SCu, Mr= 497.93, Dc= 1.783 g/cm^3,μ = 1.350 mm^-1, F(000) = 506, the final R = 0.0518 and wR = 0.1513 for 4180 observed reflections with I 〉 2σ(I). The central Cu(II) ion is five-coordinated by two oxygen atoms from the H2SIP-O^2- ligand and two nitrogen atoms of bpy ligand in a distorted square-planar geometry as well as a water oxygen atom in the apical position to complete a distorted square-pyramidal coordination geometry. The mononuclear copper molecules are linked by hydrogen bonds between coordinated water molecules and sulfonate groups to form a one-dimensional double-chain structure. The chains are further held together through extensive π-π stacking interactions between the aromatic rings to form a three- dimensional supramolecular structure.
文摘The growth mechanism of reinforcement in in situ synthesized (TiB+TiC)/Ti composites was investigated. The results show that reinforcements nucleate and grow in a way of dissolution precipitation. The morphologies of reinforcements are closely related to the solidification paths and crystal structure of reinforcements. TiB, as a reinforcement, is liable to grow along [010] direction and forms in short fibre shape due to its B27 structure, whereas primary TiC is liable to form composition undercooling and grow in dendritic shape. TiC phases precipitated in binary eutectic and ternary eutectic reactions grow in equiaxial shape. The addition of aluminum element refines TiB and TiC particles, and makes TiC reinforcements grow into the equiaxial particles easily. The addition of graphite adjusts the solidification paths and forms more TiC with dendritic shape. [
基金Supported by the Scientific Research Foundation of Higher Education Institutions of Ningxia(No.NGY2017004)the National Natural Science Foundation of China(Nos.21763022 and 50564043)the Major Innovation Projects for Building First-class Universities in China’s Western Region(No.ZKZD2017003)
文摘A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.
基金Supported by the National Natural Science Foundation of China(Nos.21263019 and 51364038)
文摘A new coordination compound Zn(2,4'-bpt)2(H2O)(1) based on the versatile ligand 2,4'-Hbpt(2,4?-Hbpt = 3-(2-pyridyl)-5-(4-pyridyl)-1H-1,2,4-triazole) was prepared by hydrothermal reactions. The structure of complex 1 has been characterized by X-ray single-crystal diffraction, elemental analysis, X-ray powder diffraction, IR spectrum analysis and thermogravimetric analysis. Single-crystal X-ray diffraction analysis indicates that the complex belongs to monoclinic system, space group C2/c with a = 23.877(3), b = 0.7483(9), c = 1.2492(2) A, b = 92.681(2)°, V = 2230.6(4) A^3, Z = 4, Dc = 1.572 g/cm^3, m = 1.143 mm^-1, Mr = 527.85 and F(000) = 1080. The final R = 0.0581 and wR = 0.0898 with I 〉 2s(I). 1 is a 0D motif which is connected by hydrogen bonds to form a corrugated 1D pattern. In addition, 1 shows strong photoluminescent emissions in the solid state at room temperature which can be used as potential optical materials. Theoretical calculations based on density functional theory(DFT) were employed in order to explicate the stability and chemical reactivity of 2,4'-Hbpt with different conformations. The results indicated that conformation I is more stable and prior to coordination in the reactions.
基金This work was supported by the NSF for Distinguished Young Scientist of China (20425104) and the NSF of Fujian Province (A0420002, 2005I017)
文摘A new Cu(Ⅱ) complex [Cu(4-cba)(1,10-phen)(H2O)2](NO3) (4-Hcba = 4-cyanobenzoic acid) has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data: C20H16CuN4O7, Mr= 487.91, triclinic, space group PI, a = 7.8420(2), b = 9.1070(2), c = 15.1140(6) A, a = 76.889(9), β = 81.332(11), γ = 74.844( 11)°, V = 1009.89(5) A^3, Z = 2, Dc = 1.605 g/cm^3, F(000) = 498, μ = 1.134 mm^-1, the final R = 0.0379 and wR = 0.0865 for 2977 observed reflections with 1 〉 2σ(Ⅰ). The Cu(Ⅱ) atom is coordinated by two terminal water molecules, one chelating 1,10-phen molecule and one monodentate 4-cba ligand to form a slightly distorted square pyramid. The title complex molecules are connected through hydrogen bonds and π-π stacking interactions to generate a 2D layered network. The thermogravimetric analysis of the title complex has also been discussed.
基金Supported by the National Natural Science Foundation of China(No.21607051)Institute Foundation of Siping City(No.2017057)the Science and Technology Research Projects of the Education Committee of Jilin Province(No.JJKH20180779KJ)
文摘A new Cu(Ⅱ) coordination polymer, [Cu(L1)(L2)](1), was synthesized under hydrothermal conditions(H_2L1 = 4-(carboxymethoxy)benzoic acid, L2 = 2-(4-fluorophenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Crystallographic data for 1: triclinic, space group P1 with a = 9.750(5), b = 10.148(5), c = 12.869(5) ?, α = 104.904(5), β = 102.133(5), γ = 95.219(5)°, V = 1188.7(10) ?~3, Z = 2, C_(28)H_(17)FN_4O_5Cu, Mr = 572.01, D_c = 1.598 g/cm^3, F(000) = 582, μ(MoKa) = 0.977 mm^(-1), R = 0.0474 and w R = 0.1144. The TGA behaviors and luminescence of 1 have been studied in detail. The L1 dianions link neighboring Cu(Ⅱ) atoms in a bis-chelating mode, yielding a one-dimensional chain structure along the b axis. The L2 ligands are attached on one side of the chain through chelating the Cu(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. Additionally, the N–H???O hydrogen bonds further stabilize the structure of 1.
基金Supported by the Institute Foundation of Siping City(No.2013036)
文摘A new Zn(II) complex, [Zn(L)(IPP)(H2O)]'2H2O(1, H2L = 3-carboxy-l-car- boxymethyl-2-oxidopyridinium and IPP = 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)phenol), was synthesized under hydrothermal conditions and its structure was determined by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pi with a = 8.5023(17), b = 9.945(2), c = 15.573(3) A, a = 95.87(3), β = 102.56(3), y = 100.73(3)°, V= 1248.7(4) A3, Z= 2, C27H22N5O9Zn, Mr= 625.87, Dc = 1.665 g/cm^3, F(000) = 642, μ(MoKa) = 1.053 mm^-1, R = 0.0474 and wR = 0.1352. In 1, one L2-, one 1PP and one water molecule coordinate to the same Zn(II) atom to give a discrete complex with two lattice water molecules. Adjacent [Zn(L)(IPP)(H20)].2H20 molecules interact through π-π stacking between two IPP ligands to form a supramolecular chain. The N-H…O and O-H…N hydrogen bonds further stabilize the supramolecular chain structure of 1. The solid state luminescent property of 1 was also studied.
基金Supported by the Natural Science Foundation of Hunan Province (No. 07JJ302)
文摘The title compound (E)-4-tert-butyl-N-(2,4-dichlorobenzylidene)-5-(1,2,4-triazol-1-yl)-thiazol-2-amine was synthesized by the reaction of 4-tert-butyl-5-(1,2,4-triazol-1-yl)-thiazol-2-amine with 2,4-dichlorobenzaldehyde, and its crystal structure was determined by singlecrystal X-ray diffraction. The crystal belongs to the triclinic system, space group P1 with a = 7.9748(4), b = 10.1803(5), c = 11.4603(6), α = 102.882(1), β = 100.253(1), γ = 104.457(1)°, V = 850.95(7)3, Z = 2, F(000) = 392, C16H15Cl2N5S, Mr = 380.29, Dc = 1.484 g/cm3, S = 1.095, μ = 0.512 mm-1, the final R = 0.0301 and wR = 0.0965 for 3334 observed reflections (I 〉 2σ(I)). The preliminary antitumor activity shows that for the title compound the IC50 of Hela is 0.175 μmol/mL and that of Bel7402 is 0.156 μmol/mL.
基金supported by the National Natural Science Foundation of China(21501012 and 51203012)
文摘Two new Cd(Ⅱ) coordination polymers, [Cd(PT)(1,4-BDC)0.5]n (1) and [Cd(PT) (1,3-BDC)0.5]n (2) (HPT = 3-(pyridin-2-yl)-1,2,4-triazole, 1,4-H2BDC = 1,4-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid), have been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction as well as elemental analysis and IR. Complexes 1 and 2 are both three-dimensional coordination polymers with two-dimensional sheet structures bridged by the deprotonated carboxylate ligands. In 1, 1,4-BDC2- bridges the layered network to generate a quadrangular framework, and 2 owns a sexangular framework, which was caused by the different steric hindrance between 1,4-BDC^2- and 1,3-BDC^2-. Their thermal stabilities and photoluminescent properties have been also investigated.