We propose and demonstrate a pseudo Fabry–Pérot filter in the terahertz frequency range of 0.1–0.5 THz. It consists of alternative liquid crystal layers and metallic slats. Separate sharp resonant peaks are sho...We propose and demonstrate a pseudo Fabry–Pérot filter in the terahertz frequency range of 0.1–0.5 THz. It consists of alternative liquid crystal layers and metallic slats. Separate sharp resonant peaks are shown in the simulated transmission spectra, and their positions shift toward higher frequencies when the refractive index of liquid crystal decreases. The measured transmission spectra are consistent with corresponding simulations. Via thermally tuning the refractive index of the filled liquid crystal, the resonant transmission frequencies shift accordingly. The work supplies a novel design for tunable terahertz filters, which would play important roles in terahertz imaging, sensing, high speed communication, and security applications.展开更多
The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry (FAAS) were investigated. It was found that boric acid as a matrix modifier obviously e...The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry (FAAS) were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL^-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%- 101%, the sensitivity is 0.19 μg.mL^-l and the detection limit is 77 ng.mL^-1. The effect of the determination of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.展开更多
The crystal structure of a novel Eu^(3+) coordination polymer, {[Eu(m-BDC)(NO_3)(Phen)(H_2O)]_2·2CH_3CH_2OH}_n (m-BDC=1,3-benzenedicarboxylate, Phen=1, 10-phenanthroline), was obtained and its high-resolution lum...The crystal structure of a novel Eu^(3+) coordination polymer, {[Eu(m-BDC)(NO_3)(Phen)(H_2O)]_2·2CH_3CH_2OH}_n (m-BDC=1,3-benzenedicarboxylate, Phen=1, 10-phenanthroline), was obtained and its high-resolution luminescence spectra at 77K were measured. The μ_2-carboxylate of m-BDC constructs the binuclear building block in which each Eu^(3+) ion is coordinated by four oxygen atoms of m-BDC anions, one oxygen atom from water molecule, two oxygen atoms of nitrate and two nitrogen atoms of Phen, respectively. The μ_1-carboxylate of m-BDC conjugates the binuclear units one-dimensional chain or a ribbon, while the hydrogen bonds between ribbons assemble the structure two-dimensional layer with a thickness equaling to the width of the ribbon. The luminescence spectra reveal that the two Eu^(3+) ion sites in the binuclear building blocks have slight environmental difference. The C_1 local symmetry of Eu^(3+) ion is concluded from both crystal structure measurement and luminescence spectra.展开更多
We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement...We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided.展开更多
A new thiostannate,[tmdpH2]Sn3S7 1(tmdp = 4,4'-trimethylenedipiperidine),has been synthesized under solvothermal conditions and characterized by elemental analysis,IR spectroscopy,and single-crystal X-ray diffracti...A new thiostannate,[tmdpH2]Sn3S7 1(tmdp = 4,4'-trimethylenedipiperidine),has been synthesized under solvothermal conditions and characterized by elemental analysis,IR spectroscopy,and single-crystal X-ray diffraction analysis.In 1,the Sn3S4 secondary incomplete cubane-like building units are bridged by μ2-S atoms to form Sn12S12 rings which are then joined parallelly to the [001] plane,giving the final 2D(Sn3S7^2-)n layer of(6,3) network.The layers are stacked along the c axis so that 24-membered ring channels are generated,in which the organic cations are accommodated.The compound crystallizes in monoclinic,space group C2/c,with a=23.052(3),b=13.4039(12),c=18.412(2)A,β=120.112(4)°,V=4921.3(9)A^3,C13H28N2S7Sn3,Mr=792.86,Z=8,Dc=2.140 g/cm^3,F(000)=3056,μ=3.619 mm^-1,the final R=0.0488 and wR=0.1125 for 4607 observed reflections with I〉2σ(I).展开更多
A novel Nd(Ⅲ) compound,[Nd3(OH)7(O2CC6H4SO3)(H2O)]n·nH2O 1,has been synthesized by the hydrothermal reaction of Nd2O3 and 3-sulfobenzoic acid monosodium salt. It was characterized by IR spectroscopy,elem...A novel Nd(Ⅲ) compound,[Nd3(OH)7(O2CC6H4SO3)(H2O)]n·nH2O 1,has been synthesized by the hydrothermal reaction of Nd2O3 and 3-sulfobenzoic acid monosodium salt. It was characterized by IR spectroscopy,elemental analysis,thermogravimetric analysis and single-crystal X-ray diffraction. It crystallizes in monoclinic,space group P21/c with a = 13.024(3),b = 10.961(2),c = 12.792(3) ,β = 91.271(3)°,V = 1825.6(7) 3,Z = 4,Mr = 787.97,Dc = 2.867 g/cm3,μ = 8.584 mm-1,F(000) = 1460,S = 1.035,R = 0.0442 and wR = 0.1166 (I 〉 2σ(I)). In this compound,the cross-linkage of Nd atoms by bridging hydroxy groups results in a Nd-O inorganic 〈200〉 layer,and such layers are linked by the 3-O3S-C6H4-CO2 dianions into a pillar-layered structure. The lattice water molecules are located in the cavity.展开更多
The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed ...The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed the crystal orientation of nacreous layers with different color prepared from fresh water clams Hyriopsis cumingii Lea by X ray diffraction . The results show that the crystal CaCO 3 orientation on specific plane is responsible for the color of pearl and nacreous pearl color.展开更多
The inclusion crystal formed by the hexamethylenamine with p-nitrophenol has a layer type structure,and is divided or- ganic layer and inorganic layer,the latter has a width of 1.0136nm.Metal ions can enter hydrated ...The inclusion crystal formed by the hexamethylenamine with p-nitrophenol has a layer type structure,and is divided or- ganic layer and inorganic layer,the latter has a width of 1.0136nm.Metal ions can enter hydrated layer of the crystal,the con- tents of the cations and water in the crystal are determined.The XRD analysis of the layer type structure of the crystal is also giv- en.展开更多
The title complex [Zn(-O2CCH=CHCO2)(C3H4N2)(H2O)]n was prepared by the reaction of zinc carbonate with maleic acid and imidazole in an aqueous-alcohol solution at 333 K, and its crystal structure has been solved by si...The title complex [Zn(-O2CCH=CHCO2)(C3H4N2)(H2O)]n was prepared by the reaction of zinc carbonate with maleic acid and imidazole in an aqueous-alcohol solution at 333 K, and its crystal structure has been solved by single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group Pc with a = 5.3858(7), b = 22.685(3), c = 7.6782(1) ? = 92.261(2)o, V = 937.4(2) 3, Z = 1, C14H16N4O10Zn2, Mr = 531.05, Dc = 1.882 g/cm3, = 2.623 mm1, F(000) = 532, the final R = 0.0372 and wR = 0.0930 for 1926 observed reflections with I>2s(I). The central zinc atom is five-coordinated in a distorted square pyramidal environment to three oxygen atoms of two different maleate ligands, a nitrogen atom of the imi- dazole ligand and an oxygen atom of water. In the complex two carboxylate groups of the maleate ligands have two coordination modes. One acts as a bidentate chelate ligand and the other a monoatomic monodentate ligand to bridge two zinc centers. As a result, 1-D infinite polymeric chains are formed, which are linked together by pairs of OH…O hydrogen bonds between the coordination water OH groups and carboxylate oxygen atoms to construct a 2-D layered polymer, and the layer structure is stabilized by p-p stacking of the imidozel ligands.展开更多
Investigation of the electric properties of semi-conducting materials in an applied ac electric fields gives information about the nature of charge transport and localized states in the forbidden gap. Layered crystals...Investigation of the electric properties of semi-conducting materials in an applied ac electric fields gives information about the nature of charge transport and localized states in the forbidden gap. Layered crystals usually contain structural defects, such as dislocations and vacancies that may form a high density of localized states near the Fermi level. So, the current study was carried out for insight into the dielectric Properties of Tl2S layered single crystals. These properties were studied using the ac measurements in the low temperatures ranging from 77 to 300 K. The real part of dielectric constant ε?, imaginary part of dielectric constant ε?, the dissipation factor tan δ and the alternating current conductivity σac were measured in an applied ac electric field of frequencies extending from 2.5 to 50 kHz. Based on the dependencies of these dielectric parameters on both the frequency and temperature, the dielectric properties of the crystals under investigation were elucidated and analyzed. The ac conductivity was found to obey the power law σac(ω) = Aωs with which the values of the exponent s were evaluated to be less than unity in the range 0.21 ≥ s ≥ 0.19. Furthermore, it was found that the temperature dependence of ac conductivity follows the Arrhenius relation via which the impact of temperature on the electrical processes in an applied ac electric field was illustrated and analyzed. The influences of temperature and frequency on both the exponent s and band gap were also discussed in this investigation.展开更多
A novel layered mixed metal vanadium-cobadt complex, (py)5Co2(H2O)3[V4O12] 1 (py = pyridine), was hydro(solvo)thermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in ort...A novel layered mixed metal vanadium-cobadt complex, (py)5Co2(H2O)3[V4O12] 1 (py = pyridine), was hydro(solvo)thermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group Pca21 with a = 17.473(4), b = 11.447(2), c = 17.509(4)A^°, V = 5005.3(7)A^°3, Z = 4, Mr = 3502.1(12), Z = 4, Dc = 1.827 g/cm^3,μ(MoKα) = 2.023 mm^-1, F(000) = 1928, S = 1.020, the final R = 0.0400 and wR= 0.1063 for 6035 observed reflections with I 〉 2σ(I) and 460 variables. Complex 1 consists of tetrahedral VO4 groups to form the large layers which are alternately bonded by two cobalt complex species Co(py)2(H2O)2 and Co(py)3(H2O).展开更多
In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer (Boltom-TM H30) to prepare a hyperbranched photosensitive polymer (H30-Ci). The polymer was characterized by UV absorp...In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer (Boltom-TM H30) to prepare a hyperbranched photosensitive polymer (H30-Ci). The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization (LPP) method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal (LC) cells containing nematic liquid crystal (5CB). The observation by polarized microscope showed that the H30-Ci blended with a linear polymer (BP-AN-Ci) photo-alignment layers could align LC molecules in a very uniform way.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11304151,61490714,61435008,and 61575093)the Ph.D.Programs Foundation of the Ministry of Education of China(No.20120091120020)the Fundamental Research Funds for the Central Universities(Nos.021314380020 and 021314380023)
文摘We propose and demonstrate a pseudo Fabry–Pérot filter in the terahertz frequency range of 0.1–0.5 THz. It consists of alternative liquid crystal layers and metallic slats. Separate sharp resonant peaks are shown in the simulated transmission spectra, and their positions shift toward higher frequencies when the refractive index of liquid crystal decreases. The measured transmission spectra are consistent with corresponding simulations. Via thermally tuning the refractive index of the filled liquid crystal, the resonant transmission frequencies shift accordingly. The work supplies a novel design for tunable terahertz filters, which would play important roles in terahertz imaging, sensing, high speed communication, and security applications.
文摘The effects of matrix silicate and experimental conditions on the determination of iron in flame atomic absorption spectrometry (FAAS) were investigated. It was found that boric acid as a matrix modifier obviously eliminated silicate interference. Under the optimum operating conditions, the determination results of iron in layered crystal sodium disilicate and sodium silicate samples by FAAS were satisfactory. The linear range of calibration curve is 0-10.5 μg.mL^-1, the relative standard deviation of method is 1.2%-2.2%, the recovery of added iron is 96.0%- 101%, the sensitivity is 0.19 μg.mL^-l and the detection limit is 77 ng.mL^-1. The effect of the determination of iron of the standard curve method, standard addition calibration and colorimetry method was the same, but the first has the merits of rapid sample preparation, reduced contamination risks and fast analysis.
文摘The crystal structure of a novel Eu^(3+) coordination polymer, {[Eu(m-BDC)(NO_3)(Phen)(H_2O)]_2·2CH_3CH_2OH}_n (m-BDC=1,3-benzenedicarboxylate, Phen=1, 10-phenanthroline), was obtained and its high-resolution luminescence spectra at 77K were measured. The μ_2-carboxylate of m-BDC constructs the binuclear building block in which each Eu^(3+) ion is coordinated by four oxygen atoms of m-BDC anions, one oxygen atom from water molecule, two oxygen atoms of nitrate and two nitrogen atoms of Phen, respectively. The μ_1-carboxylate of m-BDC conjugates the binuclear units one-dimensional chain or a ribbon, while the hydrogen bonds between ribbons assemble the structure two-dimensional layer with a thickness equaling to the width of the ribbon. The luminescence spectra reveal that the two Eu^(3+) ion sites in the binuclear building blocks have slight environmental difference. The C_1 local symmetry of Eu^(3+) ion is concluded from both crystal structure measurement and luminescence spectra.
基金Supported by the Ministry of Education and Science of the Russian Federation under Grant No 2271
文摘We describe theoretically the grounded method of measuring the conductivity of anisotropic layered semiconductor materials. The suggested method implies the use of a four-probe testing device with a linear arrangement of probes. The final expressions for identifying the electrical conductivity are presented in the form of a series of analytic functions. The suggested method is experimentally verified, and practical recommendations of how to apply it are also provided.
基金supported by the 973 Program (2007CB815301 and 2006CB932904)the National Natural Science Foundation of China (20333070, 20673118, 20871114)+1 种基金the Science Foundation of CAS (KJCX2-YW-M05)Fujian Province (2006L2005, 2006J0014, 2006F3132)
文摘A new thiostannate,[tmdpH2]Sn3S7 1(tmdp = 4,4'-trimethylenedipiperidine),has been synthesized under solvothermal conditions and characterized by elemental analysis,IR spectroscopy,and single-crystal X-ray diffraction analysis.In 1,the Sn3S4 secondary incomplete cubane-like building units are bridged by μ2-S atoms to form Sn12S12 rings which are then joined parallelly to the [001] plane,giving the final 2D(Sn3S7^2-)n layer of(6,3) network.The layers are stacked along the c axis so that 24-membered ring channels are generated,in which the organic cations are accommodated.The compound crystallizes in monoclinic,space group C2/c,with a=23.052(3),b=13.4039(12),c=18.412(2)A,β=120.112(4)°,V=4921.3(9)A^3,C13H28N2S7Sn3,Mr=792.86,Z=8,Dc=2.140 g/cm^3,F(000)=3056,μ=3.619 mm^-1,the final R=0.0488 and wR=0.1125 for 4607 observed reflections with I〉2σ(I).
基金supported by the Natural Science Foundation for Youths in Jiangxi Province (No. 2008GQH0002)
文摘A novel Nd(Ⅲ) compound,[Nd3(OH)7(O2CC6H4SO3)(H2O)]n·nH2O 1,has been synthesized by the hydrothermal reaction of Nd2O3 and 3-sulfobenzoic acid monosodium salt. It was characterized by IR spectroscopy,elemental analysis,thermogravimetric analysis and single-crystal X-ray diffraction. It crystallizes in monoclinic,space group P21/c with a = 13.024(3),b = 10.961(2),c = 12.792(3) ,β = 91.271(3)°,V = 1825.6(7) 3,Z = 4,Mr = 787.97,Dc = 2.867 g/cm3,μ = 8.584 mm-1,F(000) = 1460,S = 1.035,R = 0.0442 and wR = 0.1166 (I 〉 2σ(I)). In this compound,the cross-linkage of Nd atoms by bridging hydroxy groups results in a Nd-O inorganic 〈200〉 layer,and such layers are linked by the 3-O3S-C6H4-CO2 dianions into a pillar-layered structure. The lattice water molecules are located in the cavity.
文摘The pearl or nacreous layer of mollusk shell is composed of CaCO 3 aragonite crystals. The factors affecting their color are very complex, such as metal elements, chromoprotein, and nucleation materials. we analyzed the crystal orientation of nacreous layers with different color prepared from fresh water clams Hyriopsis cumingii Lea by X ray diffraction . The results show that the crystal CaCO 3 orientation on specific plane is responsible for the color of pearl and nacreous pearl color.
基金This work is supported by the Excellent Young Tcachers Foundation the State Education Commission of China
文摘The inclusion crystal formed by the hexamethylenamine with p-nitrophenol has a layer type structure,and is divided or- ganic layer and inorganic layer,the latter has a width of 1.0136nm.Metal ions can enter hydrated layer of the crystal,the con- tents of the cations and water in the crystal are determined.The XRD analysis of the layer type structure of the crystal is also giv- en.
基金Supported by the National Natural Science Foundation of China (No. 29872037) and the Natural Science Foundation of Fujian province (No. C0120002)
文摘The title complex [Zn(-O2CCH=CHCO2)(C3H4N2)(H2O)]n was prepared by the reaction of zinc carbonate with maleic acid and imidazole in an aqueous-alcohol solution at 333 K, and its crystal structure has been solved by single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group Pc with a = 5.3858(7), b = 22.685(3), c = 7.6782(1) ? = 92.261(2)o, V = 937.4(2) 3, Z = 1, C14H16N4O10Zn2, Mr = 531.05, Dc = 1.882 g/cm3, = 2.623 mm1, F(000) = 532, the final R = 0.0372 and wR = 0.0930 for 1926 observed reflections with I>2s(I). The central zinc atom is five-coordinated in a distorted square pyramidal environment to three oxygen atoms of two different maleate ligands, a nitrogen atom of the imi- dazole ligand and an oxygen atom of water. In the complex two carboxylate groups of the maleate ligands have two coordination modes. One acts as a bidentate chelate ligand and the other a monoatomic monodentate ligand to bridge two zinc centers. As a result, 1-D infinite polymeric chains are formed, which are linked together by pairs of OH…O hydrogen bonds between the coordination water OH groups and carboxylate oxygen atoms to construct a 2-D layered polymer, and the layer structure is stabilized by p-p stacking of the imidozel ligands.
文摘Investigation of the electric properties of semi-conducting materials in an applied ac electric fields gives information about the nature of charge transport and localized states in the forbidden gap. Layered crystals usually contain structural defects, such as dislocations and vacancies that may form a high density of localized states near the Fermi level. So, the current study was carried out for insight into the dielectric Properties of Tl2S layered single crystals. These properties were studied using the ac measurements in the low temperatures ranging from 77 to 300 K. The real part of dielectric constant ε?, imaginary part of dielectric constant ε?, the dissipation factor tan δ and the alternating current conductivity σac were measured in an applied ac electric field of frequencies extending from 2.5 to 50 kHz. Based on the dependencies of these dielectric parameters on both the frequency and temperature, the dielectric properties of the crystals under investigation were elucidated and analyzed. The ac conductivity was found to obey the power law σac(ω) = Aωs with which the values of the exponent s were evaluated to be less than unity in the range 0.21 ≥ s ≥ 0.19. Furthermore, it was found that the temperature dependence of ac conductivity follows the Arrhenius relation via which the impact of temperature on the electrical processes in an applied ac electric field was illustrated and analyzed. The influences of temperature and frequency on both the exponent s and band gap were also discussed in this investigation.
基金supported by the Science and Technological Fund of Anhui Province for Outstanding Youth and the Program for New Century Excellent Talents in University (06046100 and NCET-06-0556)
文摘A novel layered mixed metal vanadium-cobadt complex, (py)5Co2(H2O)3[V4O12] 1 (py = pyridine), was hydro(solvo)thermally synthesized and characterized by single-crystal X-ray diffraction. It crystallizes in orthorhombic, space group Pca21 with a = 17.473(4), b = 11.447(2), c = 17.509(4)A^°, V = 5005.3(7)A^°3, Z = 4, Mr = 3502.1(12), Z = 4, Dc = 1.827 g/cm^3,μ(MoKα) = 2.023 mm^-1, F(000) = 1928, S = 1.020, the final R = 0.0400 and wR= 0.1063 for 6035 observed reflections with I 〉 2σ(I) and 460 variables. Complex 1 consists of tetrahedral VO4 groups to form the large layers which are alternately bonded by two cobalt complex species Co(py)2(H2O)2 and Co(py)3(H2O).
基金the National Natural Science Foundation of China (No. 50103005)Thanks for Professor Shi Wenfang of University of Science and Technology of China to supply the hyperbranched polymer(H30).
文摘In this work, 4-methoxylcinnamoyl chloride was reacted with a commercial hyperbranched polymer (Boltom-TM H30) to prepare a hyperbranched photosensitive polymer (H30-Ci). The polymer was characterized by UV absorption spectrum and 1H- NMR spectrum. After processed by Linearly Polarized Polymerization (LPP) method, the spin-coated films of H30-Ci were used as photo-alignment layers to assemble liquid crystal (LC) cells containing nematic liquid crystal (5CB). The observation by polarized microscope showed that the H30-Ci blended with a linear polymer (BP-AN-Ci) photo-alignment layers could align LC molecules in a very uniform way.