Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simpl...Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simple structure, low cost and easy layout, therefore it has become a research hotspot in recent years. In this paper, the multimode fiber with large core is used for manufacturing SMS structure with high sensitivity. Firstly, the multimode fiber with core/cladding diameters of 105/ 125 jitm has access to the system by means of single mode optical fiber. Secondly, SMS device structure is manufactured by welding the eccentric shaft of multimode optical fiber. Afterwards, mode interference effect and spectral response characteristics of the structure of single mode-multimode-single mode optical fiber are analyzed theoretically. Finally, with the help of a wide spectrum light source and a spectrum analyzer, the transmission spectra characteristics of SMS optical fiber with strain is tested. By observing the curve that the wave changes with stress, the sensitivity is calculated and it is consistent with theoretical value .展开更多
A novel coordination polymer [Sm（4-Pyta）3（H2O）2]n has been synthesized by the hydrothermal reaction between 4-Pyta （4-Pyta = 4-pyridylthioacetate） and Sm（NO3）3. The structure was characterized by elemental ana...A novel coordination polymer [Sm（4-Pyta）3（H2O）2]n has been synthesized by the hydrothermal reaction between 4-Pyta （4-Pyta = 4-pyridylthioacetate） and Sm（NO3）3. The structure was characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space groupP1, with a = 9.100（2）, b = 11.842（3）, c = 12.183（3） A, α= 79.781（4）, β= 74.124（4）, γ = 841882（5）^o, V = 1241.6（5） A^3, Z = 2, Mr = 690.95, Dc = 1.84806 g/cm^3, F（000） = 686,μ = 2.669 mm^-1, the final R = 0.0388 and wR = 0.0808 for 4149 observed reflections with I 〉 2σ（I）. The structural analysis shows that the complex exhibits a one-dimensional architecture. Intermolecular hydrogen bonding interactions are found in the complex molecules.展开更多
The electronic structure and chemical bonding of the title comp- lexes have been studied by an unrestricted INDO program made applicable for the lanthanoid compounds.The results indicated:(1)In coordinated bonds O-Ln ...The electronic structure and chemical bonding of the title comp- lexes have been studied by an unrestricted INDO program made applicable for the lanthanoid compounds.The results indicated:(1)In coordinated bonds O-Ln and N-Ln,5d orbitals of Ln have large contribution in all valence orbitals of Ln and 4f orbitals have very small contribution.(2)The covalent chara- cter and ionic character are almost equal in the chemical bond which is comparatively weak between phen,C_2H_5OH and Ln are mainly ionic with some covalent character.展开更多
The binuclear complex Sm2(C12H8N2)2(C6H5COO)6 has been prepared and structurally analyzed by single crystal Xray diffraction. The complex crystallizes in the triclinic system, space group P1 , with a=10.833(2), b=11...The binuclear complex Sm2(C12H8N2)2(C6H5COO)6 has been prepared and structurally analyzed by single crystal Xray diffraction. The complex crystallizes in the triclinic system, space group P1 , with a=10.833(2), b=11.937(2), c=12.448(3) , = 104.97(3), = 93.63(3), = 113.27(3), V=1403.5 3, Dc=1.64g/cm3, =21.42cm-1, F(000)=690, Z=1, final R=0.037, Rw=0.077 for 4855 observed reflections I>2(I) and 5703 independent reflections. In the molecule, each Sm atom is coordinated by seven O atoms and two N atoms forming an irregular coordination polyhedron.展开更多
The alloy with nominal composition Sm_2(Fe0.94Ti0.06)17 is prepared by arc-melting, hydrogenation and nitrogenation processes. The Sm_2(Fe0.94Ti0.06)17 alloy has a single phase of Sm_3(Fe, Ti)29 with the Nd_3(Fe, Ti)...The alloy with nominal composition Sm_2(Fe0.94Ti0.06)17 is prepared by arc-melting, hydrogenation and nitrogenation processes. The Sm_2(Fe0.94Ti0.06)17 alloy has a single phase of Sm_3(Fe, Ti)29 with the Nd_3(Fe, Ti)29-type structure. The corresponding hydride phase with the same phase structure of the parent alloy was formed after a hydrogen decrepitation (HD) process at 300℃. The hydrogenation at 800℃ mainly shows a HDDR process. The HD and nitrogenation at 500℃ result in increasing the Curie temperature of the alloy by 72℃ and by 158℃ due to lattice expansions, respectively. The anisotropic and isotropic Sm_3(Fe. Ti)29N_y magnets are obtained after HD, HDDR and the consequent nitrogenation, respectively. The optimum magnetic properties of Sm_3(Fe, Ti)29N_y powders achieved in the above two processes are: (i) B_r=0;82 T, _iH_c=4.48 kA/cm. (BH)_max=54.3 kJ/m^3, (ii) B_r=0.68 T, _iH_c=8.14 kA/cm, (BH)max=66.4 kJ/m^3.展开更多
Sm2Fe17-xNbx （x = 0-4） powder was synthesized by HDDR treatment and nitrogenation. The effects of partial Nb substitution for Fe on the structural and magnetic properties of Sm2Fe17-xNbx alloys and their nitlides we...Sm2Fe17-xNbx （x = 0-4） powder was synthesized by HDDR treatment and nitrogenation. The effects of partial Nb substitution for Fe on the structural and magnetic properties of Sm2Fe17-xNbx alloys and their nitlides were investigated. It was seen that Sm2（Fe,Nb）17 phase exists in both annealed and HDDR-treated Sm2Fe17-xNbx alloys. However, its content is decreased with the increase in Nb substitution. In annealed alloys, Sm2（Fe,Nb）17 phase becomes unstable and will dissociate into SmFe2 and Fe-rich phases when x 〉 1.5. With HDDR-treatment, the Nb concentration in recombined Sm2（Fe,Nb）17 phase is decreased, and the content of Fe-rich phases is increased. Sm2Fe17-xNbx powder exhibits dendritic cracks and fine particles with a size of less than 300 nm. In nitrogenated alloys, N atoms mainly enter 2：17-type phase to form Sm2（Fe,Nb）17Ny. Partial Nb atoms in Sm2（Fe,Nb）17Ny phase will be released or excluded by nitrogen atoms. Fe-rich phases increase, and are followed by the amorphous Sm2（Fe,Nb）17Ny phase. Nb substitution for Fe with x = 0.5 and 1.0 in Sm2Fe17-xNbxNy powders increases the coercivity and remanence. But when x is greater than 2.0, Nb substitution will deteriorate the magnetic properties.展开更多
Evolutionary algorithm is time-consuming because of the large number of evolutions and much times of finite element analysis, when it is used to optimize the wing structure of a certain high altitude long endurance un...Evolutionary algorithm is time-consuming because of the large number of evolutions and much times of finite element analysis, when it is used to optimize the wing structure of a certain high altitude long endurance unmanned aviation vehicle（UAV）. In order to improve efficiency it is proposed to construct a model management framework to perform the multi-objective optimization design of wing structure. The sufficient accurate approximation models of objective and constraint functions in the wing structure optimization model are built when using the model management framework, therefore in the evolutionary algorithm a number of finite element analyses can he avoided and the satisfactory multi-objective optimization results of the wing structure of the high altitude long endurance UAV are obtained.展开更多
The crystallographic structure and intrinsic magnetic properties have been investigated in the RTiFe_(11), RTiCo_(11) and RTi(Fe_(1-X)Ni_X)_(11) compounds,where R represents Nd,Sm,Gd,Tb,Dy,Ho,Er and Y.Neutron diffract...The crystallographic structure and intrinsic magnetic properties have been investigated in the RTiFe_(11), RTiCo_(11) and RTi(Fe_(1-X)Ni_X)_(11) compounds,where R represents Nd,Sm,Gd,Tb,Dy,Ho,Er and Y.Neutron diffraction and Mossbauer spectra analyses have been used to study the nuclear and magnetic structure of these compounds.the Fe,Co,Ni and Ti atoms are found to exhibit strong site preference with f and j sites fa- voring Fe,Co and Ni atoms and the i site Ti atoms.Two different types of magnetic behavior were observed in the RTiFe_(11) and RTiCo_(11) compounds.In the former,the interatomic distance and the number of nearest neighbor atoms play essential roles.In particular,anomalous thermal expansion behavior is presented in RTiFe_(11).In the latter,the magnetic properties are essentially determined by the modification of the cobalt electronic configuration brought about by the transfer of rare earth conduction electrons to the transition 3d band.The saturation magnetization,Curie temperature and magnetocrystalline anisotropy data of RTiFe_(11), RTiCo_(11)and YTi(Fe_(1-X)Ni_X)_(11)are presented.A tempt to improve the intrinsic magnetic properties in RTiFe_(11)has been made,and the results are reported.On the basis of the crystalline field theory by using a single-ion model,the anisotropy constants and their temperature dependence of the R ions have been calcu- lated,which helps explain the spin reorientation observed in RTiFe_(11).展开更多
Based on tetradentate metalloligand LCu ([Cu(2,4-pydca)2], 2,4-pydca = pyridine-2,4-dicarboxylate) and lanthanides (Sm3+, Dy3+), two 3d-4fheterometalliccoordination polymers, namely, {[Sm2 (DMSO)4 (CH3OH) 2][LCu]3...Based on tetradentate metalloligand LCu ([Cu(2,4-pydca)2], 2,4-pydca = pyridine-2,4-dicarboxylate) and lanthanides (Sm3+, Dy3+), two 3d-4fheterometalliccoordination polymers, namely, {[Sm2 (DMSO)4 (CH3OH) 2][LCu]3·7DMSO·2CH3OH}n 1 and {[Dy2 (DMSO)3 (CH3OH)][LCu3 (DMSO)]·4DMSO·CH3OH}n 2 (DMSO = dimethyl sulfoxide), have been synthesized and well characterized by elemental analysis, Fourier-transform infrared spectroscopy, thermogravimetric and single-crystal X-ray diffraction analysis. Single-crystal X-ray analysis reveals that both 1 and 2 crystallize in the triclinic crystal system with P-1 space group and possess the 3D framework structures, which are constructed from metalloligands LCu connecting with {Sm2} and {Dy2} clusters, respectively. The 3D structure of 1 has a 6-connected single-nodal topology with the point symbol {49 × 66}, while 2 features a different framework with the point symbol of {412 × 63}. Thermogravimetric analysis exhibits that the skeleton of both 1 and 2 collapse after 350℃. Magnetic properties of 1 and 2 have also been investigated.展开更多
基金National Natural Science Foundation of China(No.61405127)Shanxi Province Science Foundation for Youths(No.2014021023-1)+1 种基金Scientific and Technologial Innovation Programs of Higher Education Institutions in ShanxiProgram for the Top Young Academic Leaders of Higher Learning Institutions of Shanxi
文摘Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simple structure, low cost and easy layout, therefore it has become a research hotspot in recent years. In this paper, the multimode fiber with large core is used for manufacturing SMS structure with high sensitivity. Firstly, the multimode fiber with core/cladding diameters of 105/ 125 jitm has access to the system by means of single mode optical fiber. Secondly, SMS device structure is manufactured by welding the eccentric shaft of multimode optical fiber. Afterwards, mode interference effect and spectral response characteristics of the structure of single mode-multimode-single mode optical fiber are analyzed theoretically. Finally, with the help of a wide spectrum light source and a spectrum analyzer, the transmission spectra characteristics of SMS optical fiber with strain is tested. By observing the curve that the wave changes with stress, the sensitivity is calculated and it is consistent with theoretical value .
基金This work was supported by the Education Office of Anhui Province (No. 2003kj255)
文摘A novel coordination polymer [Sm（4-Pyta）3（H2O）2]n has been synthesized by the hydrothermal reaction between 4-Pyta （4-Pyta = 4-pyridylthioacetate） and Sm（NO3）3. The structure was characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. The crystal belongs to the triclinic system, space groupP1, with a = 9.100（2）, b = 11.842（3）, c = 12.183（3） A, α= 79.781（4）, β= 74.124（4）, γ = 841882（5）^o, V = 1241.6（5） A^3, Z = 2, Mr = 690.95, Dc = 1.84806 g/cm^3, F（000） = 686,μ = 2.669 mm^-1, the final R = 0.0388 and wR = 0.0808 for 4149 observed reflections with I 〉 2σ（I）. The structural analysis shows that the complex exhibits a one-dimensional architecture. Intermolecular hydrogen bonding interactions are found in the complex molecules.
文摘The electronic structure and chemical bonding of the title comp- lexes have been studied by an unrestricted INDO program made applicable for the lanthanoid compounds.The results indicated:(1)In coordinated bonds O-Ln and N-Ln,5d orbitals of Ln have large contribution in all valence orbitals of Ln and 4f orbitals have very small contribution.(2)The covalent chara- cter and ionic character are almost equal in the chemical bond which is comparatively weak between phen,C_2H_5OH and Ln are mainly ionic with some covalent character.
文摘The binuclear complex Sm2(C12H8N2)2(C6H5COO)6 has been prepared and structurally analyzed by single crystal Xray diffraction. The complex crystallizes in the triclinic system, space group P1 , with a=10.833(2), b=11.937(2), c=12.448(3) , = 104.97(3), = 93.63(3), = 113.27(3), V=1403.5 3, Dc=1.64g/cm3, =21.42cm-1, F(000)=690, Z=1, final R=0.037, Rw=0.077 for 4855 observed reflections I>2(I) and 5703 independent reflections. In the molecule, each Sm atom is coordinated by seven O atoms and two N atoms forming an irregular coordination polyhedron.
基金National Natural Science FOundation of China!59571014National Natural Science FOundation of China!59725103National Natur
文摘The alloy with nominal composition Sm_2(Fe0.94Ti0.06)17 is prepared by arc-melting, hydrogenation and nitrogenation processes. The Sm_2(Fe0.94Ti0.06)17 alloy has a single phase of Sm_3(Fe, Ti)29 with the Nd_3(Fe, Ti)29-type structure. The corresponding hydride phase with the same phase structure of the parent alloy was formed after a hydrogen decrepitation (HD) process at 300℃. The hydrogenation at 800℃ mainly shows a HDDR process. The HD and nitrogenation at 500℃ result in increasing the Curie temperature of the alloy by 72℃ and by 158℃ due to lattice expansions, respectively. The anisotropic and isotropic Sm_3(Fe. Ti)29N_y magnets are obtained after HD, HDDR and the consequent nitrogenation, respectively. The optimum magnetic properties of Sm_3(Fe, Ti)29N_y powders achieved in the above two processes are: (i) B_r=0;82 T, _iH_c=4.48 kA/cm. (BH)_max=54.3 kJ/m^3, (ii) B_r=0.68 T, _iH_c=8.14 kA/cm, (BH)max=66.4 kJ/m^3.
基金This work was financially supported by the National Natural Sciences Foundation of China (No. 50271024) and the Natu-ral Science Foundation of Hebei Province, China (No.501013).
文摘Sm2Fe17-xNbx （x = 0-4） powder was synthesized by HDDR treatment and nitrogenation. The effects of partial Nb substitution for Fe on the structural and magnetic properties of Sm2Fe17-xNbx alloys and their nitlides were investigated. It was seen that Sm2（Fe,Nb）17 phase exists in both annealed and HDDR-treated Sm2Fe17-xNbx alloys. However, its content is decreased with the increase in Nb substitution. In annealed alloys, Sm2（Fe,Nb）17 phase becomes unstable and will dissociate into SmFe2 and Fe-rich phases when x 〉 1.5. With HDDR-treatment, the Nb concentration in recombined Sm2（Fe,Nb）17 phase is decreased, and the content of Fe-rich phases is increased. Sm2Fe17-xNbx powder exhibits dendritic cracks and fine particles with a size of less than 300 nm. In nitrogenated alloys, N atoms mainly enter 2：17-type phase to form Sm2（Fe,Nb）17Ny. Partial Nb atoms in Sm2（Fe,Nb）17Ny phase will be released or excluded by nitrogen atoms. Fe-rich phases increase, and are followed by the amorphous Sm2（Fe,Nb）17Ny phase. Nb substitution for Fe with x = 0.5 and 1.0 in Sm2Fe17-xNbxNy powders increases the coercivity and remanence. But when x is greater than 2.0, Nb substitution will deteriorate the magnetic properties.
文摘Evolutionary algorithm is time-consuming because of the large number of evolutions and much times of finite element analysis, when it is used to optimize the wing structure of a certain high altitude long endurance unmanned aviation vehicle（UAV）. In order to improve efficiency it is proposed to construct a model management framework to perform the multi-objective optimization design of wing structure. The sufficient accurate approximation models of objective and constraint functions in the wing structure optimization model are built when using the model management framework, therefore in the evolutionary algorithm a number of finite element analyses can he avoided and the satisfactory multi-objective optimization results of the wing structure of the high altitude long endurance UAV are obtained.
文摘The crystallographic structure and intrinsic magnetic properties have been investigated in the RTiFe_(11), RTiCo_(11) and RTi(Fe_(1-X)Ni_X)_(11) compounds,where R represents Nd,Sm,Gd,Tb,Dy,Ho,Er and Y.Neutron diffraction and Mossbauer spectra analyses have been used to study the nuclear and magnetic structure of these compounds.the Fe,Co,Ni and Ti atoms are found to exhibit strong site preference with f and j sites fa- voring Fe,Co and Ni atoms and the i site Ti atoms.Two different types of magnetic behavior were observed in the RTiFe_(11) and RTiCo_(11) compounds.In the former,the interatomic distance and the number of nearest neighbor atoms play essential roles.In particular,anomalous thermal expansion behavior is presented in RTiFe_(11).In the latter,the magnetic properties are essentially determined by the modification of the cobalt electronic configuration brought about by the transfer of rare earth conduction electrons to the transition 3d band.The saturation magnetization,Curie temperature and magnetocrystalline anisotropy data of RTiFe_(11), RTiCo_(11)and YTi(Fe_(1-X)Ni_X)_(11)are presented.A tempt to improve the intrinsic magnetic properties in RTiFe_(11)has been made,and the results are reported.On the basis of the crystalline field theory by using a single-ion model,the anisotropy constants and their temperature dependence of the R ions have been calcu- lated,which helps explain the spin reorientation observed in RTiFe_(11).
文摘Based on tetradentate metalloligand LCu ([Cu(2,4-pydca)2], 2,4-pydca = pyridine-2,4-dicarboxylate) and lanthanides (Sm3+, Dy3+), two 3d-4fheterometalliccoordination polymers, namely, {[Sm2 (DMSO)4 (CH3OH) 2][LCu]3·7DMSO·2CH3OH}n 1 and {[Dy2 (DMSO)3 (CH3OH)][LCu3 (DMSO)]·4DMSO·CH3OH}n 2 (DMSO = dimethyl sulfoxide), have been synthesized and well characterized by elemental analysis, Fourier-transform infrared spectroscopy, thermogravimetric and single-crystal X-ray diffraction analysis. Single-crystal X-ray analysis reveals that both 1 and 2 crystallize in the triclinic crystal system with P-1 space group and possess the 3D framework structures, which are constructed from metalloligands LCu connecting with {Sm2} and {Dy2} clusters, respectively. The 3D structure of 1 has a 6-connected single-nodal topology with the point symbol {49 × 66}, while 2 features a different framework with the point symbol of {412 × 63}. Thermogravimetric analysis exhibits that the skeleton of both 1 and 2 collapse after 350℃. Magnetic properties of 1 and 2 have also been investigated.
