This paper describes a Mach/Langmuir probe array with five pins and six pins, which can measure not only parallel flows and the flow perpendicular to the magnetic field but also the radial and the poloidal electric fi...This paper describes a Mach/Langmuir probe array with five pins and six pins, which can measure not only parallel flows and the flow perpendicular to the magnetic field but also the radial and the poloidal electric field E. arid E as well. Experimental measurements of the edge fluctuations, velocities of the toroidal, the poloidal flow and electric field have been carried out on both of SOL and the boundary region of HL-1M for Ohmic, biased H-mode, Lower Hybrid Current Drive (LHCD), Supersonic Molecular Beam Injection (MBI), Multi-shot Pellet Injection (MPI), Neutral Beam Injection (NBI), Ion Cyclotron Resonance Heating (ICRH) and Electric Cyclotron Resonance Heating (ECRH) discharges. The results show that the suppressions of the fluctuations are related to poloidal rotations produced by different discharge modes in the improved particle confinement property, simultaneously the change of the radial and poloidal electric field is generated and becomes more negative at the Tokamak plasma edge, and the sheared poloidal flow is related to the reduction in fluctuation level, and the poloidal velocity is mainly dominated by the E × B drift.展开更多
The property awc1 was used by many authors to obtain results concerning approximation by elements of weak Chebyshev subspaces. In this paper the author studies this property in details, by collecting the scattered res...The property awc1 was used by many authors to obtain results concerning approximation by elements of weak Chebyshev subspaces. In this paper the author studies this property in details, by collecting the scattered results concerning it and by finding new ones.展开更多
A new one-dimensional(1D) polymer, [Zn(HMIDC)(bpy)]n·2n H2O(1, H3MIDC = 2-methyl-imidazole-4,5-dicarboxylic acid, bpy = 2,2-bipyridine), has been solvothermally synthesized and characterized by single-cry...A new one-dimensional(1D) polymer, [Zn(HMIDC)(bpy)]n·2n H2O(1, H3MIDC = 2-methyl-imidazole-4,5-dicarboxylic acid, bpy = 2,2-bipyridine), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, UV-vis spectrum and fluorescence measurements. Complex 1 crystallizes in orthorhombic system, space group Pbca with a = 14.404(3), b = 8.6900(17), c = 26.570(5) , V = 3325.8(11) -3, Dc = 1.700 g/cm-3, Mr = 425.70, Z = 8, F(000) = 1744, μ = 1.522 mm-(-1), the final R = 0.0421 and w R = 0.1018. The Zn(Ⅱ) ion is six-coordinated by O and N atoms from one HMIDC ligand, two O atoms from another HMIDC ligand and two N atoms from the bpy ligand. The HMIDC anion, which acts as a tetradentate ligand, chelates two Zn ions to form a one-dimensional(1D) zigzag chain structure. We analyzed the electronic structure and orbital energies of complex 1 by DFT methods, and the results are consistent with the UV-vis spectrum. And we also discussed the luminescent mechanism of complex 1 in detail.展开更多
The electrostatic potential of carbene and nitrene,have been calculated by AB INITIO method with 6-31G** basis set,there are positive potential regions in the directions of vacant P orbitals,and negative regions in th...The electrostatic potential of carbene and nitrene,have been calculated by AB INITIO method with 6-31G** basis set,there are positive potential regions in the directions of vacant P orbitals,and negative regions in the directions of lone-pair electrons. Therefore,atoms in these molecules have different electric properties in different directions.The idea of electrophilic and nucleophilic directions of an atom in molecules should be introduced.展开更多
An experimental 2618(Al-Cu-Mg-Fe-Ni) alloy added with trace Sc and Zr was prepared by ingot metallurgy (IM) method. The aging behavior of the alloy was studied by Vickers hardness measurement at 200℃ and 300℃. and ...An experimental 2618(Al-Cu-Mg-Fe-Ni) alloy added with trace Sc and Zr was prepared by ingot metallurgy (IM) method. The aging behavior of the alloy was studied by Vickers hardness measurement at 200℃ and 300℃. and the tensile properties of alloy specimens were measured at 20℃, 200℃, 250℃ and 300℃. The microstructure was observed by using optical microscope, SEM and TEM. It was found that the addition of Sc and Zr to 2618 alloy resulted in a primary Al_3(Sc,Zr) phase which could refine the grain because it acts as nuclei of heterogeneous crystallization in the melt during solidification. The secondary Al_3(Sc,Zr) particles were full coherent with matrix and had obvious precipitation hardening effect. They also made the S' phase precipitate more homogeneous. So the strength of alloy increases at both ambient and elevated temperatures without a decrease of ductility. The ductile fracture of alloy occurs by microvoid nucleation, growth and coalescence, so the microvoid coalescence is the dominant fracture mechanism.展开更多
Synthesis of 1-(2-imidazolylazo)-2-naphthol-4-sulfonic acid is described including its physical and chemical properties and spectroscopic data. The reagent reacts with various transition metal ions to form water-solub...Synthesis of 1-(2-imidazolylazo)-2-naphthol-4-sulfonic acid is described including its physical and chemical properties and spectroscopic data. The reagent reacts with various transition metal ions to form water-soluble and colored chelates which can be decomposed by EDTA exoept cobalt chelate. Present method has good selectivity.展开更多
We focus on two new 21) materials, i.e., monolayer and bilayer silicon phosphides (Sil P1). Based on the elastic- scattering Green's function, the electronic-transport properties of two-dimensional monolayer and b...We focus on two new 21) materials, i.e., monolayer and bilayer silicon phosphides (Sil P1). Based on the elastic- scattering Green's function, the electronic-transport properties of two-dimensional monolayer and bilayer Au- Si1P1-Au molecular junctions are studied. It is found that their bandgaps are narrow (0.16eV for a monolayer molecular junction and 0.26 e V for a bilayer molecular junction). Moreover, the calculated current-voltage char- acteristics indicate that the monolayer molecular junction provides constant output current (20 hA) over a wide voltage range, and the bilayer molecular junction provides higher current (42 hA).展开更多
A new binuclear Zn^Ⅱ coordination complex,Zn2(bta)(phen)2(Cl)3(1,Hbta = 2-(1Hbenzotriazol-1-yl)acetic acid and phen = 1,10-phenanthroline),has been synthesized and characterized by single-crystal X-ray diff...A new binuclear Zn^Ⅱ coordination complex,Zn2(bta)(phen)2(Cl)3(1,Hbta = 2-(1Hbenzotriazol-1-yl)acetic acid and phen = 1,10-phenanthroline),has been synthesized and characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental,and photoluminescent analysis.Complex 1 crystallizes in triclinic system,space group P1 with a = 9.3040(19),b = 10.694(2),c =16.841(3) A°,α = 101.18(3),β = 105.77(3),γ = 91.72(3)°,V= 1575.8(5) A°3,C(32)H(22)Zn2Cl3N7O2,Mr =773.66,Dc = 1.631 g/cm^3,Z = 2,F(000) = 780,μ = 1.820 mm^-1,the final R = 0.1238 and wR =0.1131.X-ray diffraction analyses indicate that 1 displays two crystallographic independent Zn^Ⅱmetal centers with a distorted tetragonal pyramidal(ZnN4O) and a tetrahedral(ZnNCl3) geometries,respectively.The phen serves as a common N,N'-bidentate ligand,and the bta^- as a unique N,O-bridged ligand in 1.In the crystal,1 forms a stable 3D supramolecular architecture by trifurcated hydrogen bonding C-H…C1 interactions and C-H…π,π…π stacking.1 showed photo-electric conversion properties.展开更多
Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets an...Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.展开更多
The effects of Al additions on the microstructure and mechanical properties of MoSi2 have been studied. With the A1 additions from 2.5 wt pct to 5 wt pct, the siliceous grain boundary phase in hot pressed samples was ...The effects of Al additions on the microstructure and mechanical properties of MoSi2 have been studied. With the A1 additions from 2.5 wt pct to 5 wt pct, the siliceous grain boundary phase in hot pressed samples was eliminated because of the formation of Al2O3 particles. It was shown that Al and SiO2 reacted at 860℃. During the reaction, A1 atoms were mainly transferred to Al2O3 particles, and to some extent, diffused into MoSi2 grains. Both the toughness and strength of Al containing composites exceeded those of pure MoSi2 material. Bending strength and fracture toughness reach the highest value of 350 MPa, 4.05 MPa.m1/2, respectively, at ambient temperature when Al addition was of 3.5 wt pct.展开更多
The crystal structures and magnetic properties of novel Eu TrGa3-r (T=Pd, It, Rh) in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orth...The crystal structures and magnetic properties of novel Eu TrGa3-r (T=Pd, It, Rh) in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orthorhombic structure with space group of Cmcm and Z = 4. There are four kinds of nonequivalent 4c crystal positions in EuTrGaa-r unit cell, which are occupied by 4Eu, 4GaⅠ, 4(GaⅡ, T) and 4GaⅢ, respectively. EuTrGa3-r ex- hibits the complex magnetic states in low-temperature regime, with the three-, two- and one-antiferromagnetic transitions occurring for T=Ir, T=Rh and T=Pd, respectively. It might be due to the Kondo effect: a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons at low-temperature regime.展开更多
A new 3-D nickel(Ⅱ) metal-organic framework(MOFs) with formula [Ni(bib)_2(SO_4)]_n(1), where bib = 1,4-bis(imidazol-1-yl)benzene, has been synthesized and characterized by single-crystal X-ray diffraction...A new 3-D nickel(Ⅱ) metal-organic framework(MOFs) with formula [Ni(bib)_2(SO_4)]_n(1), where bib = 1,4-bis(imidazol-1-yl)benzene, has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and surface photovoltage spectroscopy(SPS). Complex 1 crystallizes in monoclinic system, space group C2/c with a = 19.5988(6), b = 9.7531(3), c = 11.8146(4) ?, β = 96.185(3)°, V = 2245.20(12) ?~3, C_(24)H_(20)N_8NiO_4S, M_r = 575.25, D_c = 1.702 g/cm^3, Z = 4, F(000) = 1184, μ = 1.011 mm-1, the final R = 0.0293 and w R = 0.0702. X-ray diffraction analyses indicated that the center Ni^(2+) ion is six-coordinated with an O_2N_4 donor set of two μ_2-SO_4^(2–) and four bib ligands, resulting in an ideal octahedral geometry. Topological analysis on complex 1 considers each Ni^(2+) as a 6-connected node, while bib and sulfate ion as linkers, giving an α-Po topology with short Schl?fli symbol 412·63. In the crystal packing, the components interact with pairs of intermolecular C–H×××O hydrogen bonds. The SPS of 1 indicates that there are positive response bands in the range of 300~600 nm showing photo-electric conversion properties.展开更多
In order to explore the impact relationship between intellectual property protection(IPP) system and technological innovation,a game model was constructed.The system of IPP is a set of game rules to protect the innova...In order to explore the impact relationship between intellectual property protection(IPP) system and technological innovation,a game model was constructed.The system of IPP is a set of game rules to protect the innovation under the background of R&D internationalization.Only when the main parties abide by the system of intellectual property,can the self-interest and collective interest of the two sides be maximized.The government must strengthen the penalties for intellectual property right(IPR) violations,reduce the cost of IPP declaration,reduce the cost of the innovator's own rights protection,and increase the cost of imitate behavior of IPR.展开更多
A novel 3D metal-organic coordination polymer with helical chains based on a flexible 5-(imidazol-1-ylmethyl)isophthalic acid(H_2L) as a main ligand and 1,2-bis(4-pyridyl)ethane(bpa) as a N-containing ancillar...A novel 3D metal-organic coordination polymer with helical chains based on a flexible 5-(imidazol-1-ylmethyl)isophthalic acid(H_2L) as a main ligand and 1,2-bis(4-pyridyl)ethane(bpa) as a N-containing ancillary ligand,[Cd L(bpa)_(0.5)]_n(1),has been obtained under hydrothermal conditions and characterized by elemental analysis,powder X-ray diffraction(PXRD),IR,thermal gravimetric analyses(TGA) and single-crystal X-ray diffraction.It crystallizes in monoclinic,space group P2_1/c with a = 10.984(2),b = 10.1829(12),c = 17.782(3) A,β = 123.156(11)o,V = 1665.1(5) A^3,Z = 4,Mr = 448.72,Dc = 1.790 g/cm^3,Rint = 0.0871,F(000) = 892,the final R = 0.0687 and w R = 0.1294 for 2920 observed reflections(I 〉 2σ(I)).In complex 1,the L^2- anions connect Cd(Ⅱ) ions to form two-dimensional metal-organic layers(Cd_2L_2)n,in which the 1D helical chains(Cd-L)_n are alternately arranged in a right-and left-handed sequence.These layers are further linked to build a 3D network by the bpa ligand.In addtion,photoluminescent properties for 1 are also investigated.展开更多
Micro-nano structured Li Fe(1-x)MnxPO4/C(0≤x≤0.05)cathodes were prepared by spray drying,followed by calcination at 700°C.The spherical Li Fe(1-x)MnxPO4/C(0≤x≤0.05)particles with the size of 0.5 to5.0...Micro-nano structured Li Fe(1-x)MnxPO4/C(0≤x≤0.05)cathodes were prepared by spray drying,followed by calcination at 700°C.The spherical Li Fe(1-x)MnxPO4/C(0≤x≤0.05)particles with the size of 0.5 to5.0μm are composed of lots of nanoparticles of 20 to 30 nm,and have the well-developed interconnected pore structure.In contrast,when Mn doping content is 3 mol%(x=0.03),the Li Fe(0.97)Mn(0.03)PO4/C demonstrates maximum specific surface area of 31.30 m^2/g,more uniform pore size and relatively better electrochemical performance.The initial discharge capacities are 161.59,157.04 and 153.13 m Ah/g at a discharge rate of 0.2,0.5 and 1 C,respectively.Meanwhile,the discharge capacity retentions are~100%after 120 cycles.The improved electrochemical performance should be attributed to higher specific surface,smaller polarization voltage,and a high Li~+diffusion rate due to the micro-nano porous structure and lattice expansion produced by Mn doping.展开更多
A simple non-isocyanate route synthesizing thermoplastic polyurethanes(TPUs) with good thermal and mechanical properties is described. Melt transurethane polycondensation of dimethyl 1,6-hexamethylene dicarbamate wi...A simple non-isocyanate route synthesizing thermoplastic polyurethanes(TPUs) with good thermal and mechanical properties is described. Melt transurethane polycondensation of dimethyl 1,6-hexamethylene dicarbamate with 1,4-butanediol and 1,6-hexanediol was conducted at different molar ratios under the catalysis of tetrabutyl titanate. A series of crystallizable non-isocyanate TPUs with high molecular weight were prepared. The TPUs were characterized by gel permeation chromatography, FT-IR, 1 H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray diffraction, AFM, and tensile tests. The TPUs exhibited Mn ranging from 12 500 to 26 400 g/mol, Mw from 16 700 to 56 400 g/mol, Tm up to 151.4 °C, and initial decomposition temperature over 241.8 °C. Their tensile strength reached 42.99 MPa with a strain at break of 30.00%. TPUs constructed simply with butylene, hexylene, and urethane linkages were successfully synthesized through a non-isocyanate route.展开更多
In this note we study the property(ω1),a variant of Weyl's theorem by means of the single valued extension property,and establish for a bounded linear operator defined on a Banach space the necessary and sufficien...In this note we study the property(ω1),a variant of Weyl's theorem by means of the single valued extension property,and establish for a bounded linear operator defined on a Banach space the necessary and sufficient condition for which property(ω1) holds.As a consequence of the main result,the stability of property(ω1) is discussed.展开更多
Nanocrystalline hydroxyapatite (HA) powders have been synthesized by precipitation using Ca(NO3)2 4H2O and? (NH4)2 HPO4 at room temperature and atmospheric pressure. Nanocomposites of HA and partially stabilized zirc...Nanocrystalline hydroxyapatite (HA) powders have been synthesized by precipitation using Ca(NO3)2 4H2O and? (NH4)2 HPO4 at room temperature and atmospheric pressure. Nanocomposites of HA and partially stabilized zirconia (HA/PSZ) were sintered at atmospheric pressure and 1300 for 2h in air. The preparation techniques, structure and me- chanical properties of these materials were characterized. The addition of nanosized PSZ reinforcing phase to HA may lead to an improvement of the macro and micro mechanical properties and not affect its biocompatibility and bioactivity. The bending strength, fracture toughness and nano-hardness were near to or greater than those for human cortical bone and human tooth (dentine and enamel). The composite was incubated in a fresh human plasma which confirmed the bioactivity of nanosized HA/PSZ materials. The bonding reaction between HA/PSZ ceramic and the plasma proteins was found, and he- matopoietic cell phosphatase (HCP) layers formed on surface of each composite incubated in human plasma for two weeks. The diameter of a single HCP globule was less than 100 nm. Furthermore, the precipitating mechanism investigation was carried out through a comparative experiment in this paper.展开更多
In this note,property (ω)and property 1 (ω)are variants of Weyl’s theorem. By means of topological uniform descent, the sufficient and necessary conditions of a bounded linear operator defined on a Hilbert spac...In this note,property (ω)and property 1 (ω)are variants of Weyl’s theorem. By means of topological uniform descent, the sufficient and necessary conditions of a bounded linear operator defined on a Hilbert space that satisfies property 1 (ω) and property (ω)is studied. Moreover, property 1 (ω)and property (ω)of 2 2operator matrices are discussed as well.展开更多
Abstract A Hilbert space operator T is said to have property (ω1) if σα(T)/σaw(T) π00(T), where σα(T) andσαw(T) denote the approximate point spectrum and the Weyl essential approximate point sp...Abstract A Hilbert space operator T is said to have property (ω1) if σα(T)/σaw(T) π00(T), where σα(T) andσαw(T) denote the approximate point spectrum and the Weyl essential approximate point spectrum of T respectively, and π00(T) ---- {λ∈ iso σ(T), 0 〈 dim N(T- λI) 〈 ∞}. Ifσα(T)/σαw(T) = π00(T), we say T satisfies property (w). In this note, we investigate the stability of the property (wi) and the property (w) under compact perturbations, and we characterize those operators for which the property (wi) and the property (w) are stable under compact perturbations.展开更多
文摘This paper describes a Mach/Langmuir probe array with five pins and six pins, which can measure not only parallel flows and the flow perpendicular to the magnetic field but also the radial and the poloidal electric field E. arid E as well. Experimental measurements of the edge fluctuations, velocities of the toroidal, the poloidal flow and electric field have been carried out on both of SOL and the boundary region of HL-1M for Ohmic, biased H-mode, Lower Hybrid Current Drive (LHCD), Supersonic Molecular Beam Injection (MBI), Multi-shot Pellet Injection (MPI), Neutral Beam Injection (NBI), Ion Cyclotron Resonance Heating (ICRH) and Electric Cyclotron Resonance Heating (ECRH) discharges. The results show that the suppressions of the fluctuations are related to poloidal rotations produced by different discharge modes in the improved particle confinement property, simultaneously the change of the radial and poloidal electric field is generated and becomes more negative at the Tokamak plasma edge, and the sheared poloidal flow is related to the reduction in fluctuation level, and the poloidal velocity is mainly dominated by the E × B drift.
文摘The property awc1 was used by many authors to obtain results concerning approximation by elements of weak Chebyshev subspaces. In this paper the author studies this property in details, by collecting the scattered results concerning it and by finding new ones.
基金Supported by Fundamental Research Foundation of Central Universities(No.142304007)Basic Key Program of Applied Basic Research of Science and Technology Commission Foundation of Hebei Province(No.15961005D)Natural Science Foundation of Liaoning Province(No.2015020665)
文摘A new one-dimensional(1D) polymer, [Zn(HMIDC)(bpy)]n·2n H2O(1, H3MIDC = 2-methyl-imidazole-4,5-dicarboxylic acid, bpy = 2,2-bipyridine), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR spectroscopy, UV-vis spectrum and fluorescence measurements. Complex 1 crystallizes in orthorhombic system, space group Pbca with a = 14.404(3), b = 8.6900(17), c = 26.570(5) , V = 3325.8(11) -3, Dc = 1.700 g/cm-3, Mr = 425.70, Z = 8, F(000) = 1744, μ = 1.522 mm-(-1), the final R = 0.0421 and w R = 0.1018. The Zn(Ⅱ) ion is six-coordinated by O and N atoms from one HMIDC ligand, two O atoms from another HMIDC ligand and two N atoms from the bpy ligand. The HMIDC anion, which acts as a tetradentate ligand, chelates two Zn ions to form a one-dimensional(1D) zigzag chain structure. We analyzed the electronic structure and orbital energies of complex 1 by DFT methods, and the results are consistent with the UV-vis spectrum. And we also discussed the luminescent mechanism of complex 1 in detail.
基金This work is supported by Scientific Fund of the Chinese Academy of Science.
文摘The electrostatic potential of carbene and nitrene,have been calculated by AB INITIO method with 6-31G** basis set,there are positive potential regions in the directions of vacant P orbitals,and negative regions in the directions of lone-pair electrons. Therefore,atoms in these molecules have different electric properties in different directions.The idea of electrophilic and nucleophilic directions of an atom in molecules should be introduced.
文摘An experimental 2618(Al-Cu-Mg-Fe-Ni) alloy added with trace Sc and Zr was prepared by ingot metallurgy (IM) method. The aging behavior of the alloy was studied by Vickers hardness measurement at 200℃ and 300℃. and the tensile properties of alloy specimens were measured at 20℃, 200℃, 250℃ and 300℃. The microstructure was observed by using optical microscope, SEM and TEM. It was found that the addition of Sc and Zr to 2618 alloy resulted in a primary Al_3(Sc,Zr) phase which could refine the grain because it acts as nuclei of heterogeneous crystallization in the melt during solidification. The secondary Al_3(Sc,Zr) particles were full coherent with matrix and had obvious precipitation hardening effect. They also made the S' phase precipitate more homogeneous. So the strength of alloy increases at both ambient and elevated temperatures without a decrease of ductility. The ductile fracture of alloy occurs by microvoid nucleation, growth and coalescence, so the microvoid coalescence is the dominant fracture mechanism.
文摘Synthesis of 1-(2-imidazolylazo)-2-naphthol-4-sulfonic acid is described including its physical and chemical properties and spectroscopic data. The reagent reacts with various transition metal ions to form water-soluble and colored chelates which can be decomposed by EDTA exoept cobalt chelate. Present method has good selectivity.
基金Supported by the National Natural Science Foundation of China under Grant No 11374033
文摘We focus on two new 21) materials, i.e., monolayer and bilayer silicon phosphides (Sil P1). Based on the elastic- scattering Green's function, the electronic-transport properties of two-dimensional monolayer and bilayer Au- Si1P1-Au molecular junctions are studied. It is found that their bandgaps are narrow (0.16eV for a monolayer molecular junction and 0.26 e V for a bilayer molecular junction). Moreover, the calculated current-voltage char- acteristics indicate that the monolayer molecular junction provides constant output current (20 hA) over a wide voltage range, and the bilayer molecular junction provides higher current (42 hA).
基金supported by Guangxi Provincial Department of Education(No.KY2015ZD130)the Natural Science Foundation of Guangxi Province(No.2013GXNSFBA019030)the financial support from the Natural Science Foundation of Qinzhou University(No.2014PY-GJ05)
文摘A new binuclear Zn^Ⅱ coordination complex,Zn2(bta)(phen)2(Cl)3(1,Hbta = 2-(1Hbenzotriazol-1-yl)acetic acid and phen = 1,10-phenanthroline),has been synthesized and characterized by single-crystal X-ray diffraction,IR spectroscopy,elemental,and photoluminescent analysis.Complex 1 crystallizes in triclinic system,space group P1 with a = 9.3040(19),b = 10.694(2),c =16.841(3) A°,α = 101.18(3),β = 105.77(3),γ = 91.72(3)°,V= 1575.8(5) A°3,C(32)H(22)Zn2Cl3N7O2,Mr =773.66,Dc = 1.631 g/cm^3,Z = 2,F(000) = 780,μ = 1.820 mm^-1,the final R = 0.1238 and wR =0.1131.X-ray diffraction analyses indicate that 1 displays two crystallographic independent Zn^Ⅱmetal centers with a distorted tetragonal pyramidal(ZnN4O) and a tetrahedral(ZnNCl3) geometries,respectively.The phen serves as a common N,N'-bidentate ligand,and the bta^- as a unique N,O-bridged ligand in 1.In the crystal,1 forms a stable 3D supramolecular architecture by trifurcated hydrogen bonding C-H…C1 interactions and C-H…π,π…π stacking.1 showed photo-electric conversion properties.
基金funded by Eurostars project,grant number E!12764。
文摘Human salivary histatin 1(Hst1)exhibits a series of cell-activating properties,such as promoting cell spreading,migration,and metabolic activity.We recently have shown that fluorescently labeled Hst1(F-Hst1)targets and activates mitochondria,presenting an important molecular mechanism.However,its regulating signaling pathways remain to be elucidated.We investigated the influence of specific inhibitors of G protein-coupled receptors(GPCR),endocytosis pathways,extracellular signal-regulated kinases1/2(ERK1/2)signaling,p38 signaling,mitochondrial respiration and Na+/K+-ATPase activity on the uptake,mitochondria-targeting and-activating properties of F-Hst1.We performed a si RNA knockdown(KD)to assess the effect of Sigma-2 receptor(S2R)/Transmembrane Protein 97(TMEM97)—a recently identified target protein of Hst1.We also adopted live cell imaging to monitor the whole intracellular trafficking process of F-Hst1.Our results showed that the inhibition of cellular respiration hindered the internalization of F-Hst1.The inhibitors of GPCR,ERK1/2,phagocytosis,and clathrin-mediated endocytosis(CME)as well as siRNA KD of S2R/TMEM97 significantly reduced the uptake,which was accompanied by the nullification of the promoting effect of F-Hst1 on cell metabolic activity.Only the inhibitor of CME and KD of S2R/TMEM97 significantly compromised the mitochondria-targeting of Hst1.We further showed the intracellular trafficking and targeting process of F-Hst1,in which early endosome plays an important role.Overall,phagocytosis,CME,GPCR,ERK signaling,and S2R/TMEM97 are involved in the internalization of Hst1,while only CME and S2R/TMEM97 are critical for its subcellular targeting.The inhibition of either internalization or mitochondria-targeting of Hst1 could significantly compromise its mitochondria-activating property.
文摘The effects of Al additions on the microstructure and mechanical properties of MoSi2 have been studied. With the A1 additions from 2.5 wt pct to 5 wt pct, the siliceous grain boundary phase in hot pressed samples was eliminated because of the formation of Al2O3 particles. It was shown that Al and SiO2 reacted at 860℃. During the reaction, A1 atoms were mainly transferred to Al2O3 particles, and to some extent, diffused into MoSi2 grains. Both the toughness and strength of Al containing composites exceeded those of pure MoSi2 material. Bending strength and fracture toughness reach the highest value of 350 MPa, 4.05 MPa.m1/2, respectively, at ambient temperature when Al addition was of 3.5 wt pct.
基金Supported by the National Natural Science Foundation of China under Grant No 11274110
文摘The crystal structures and magnetic properties of novel Eu TrGa3-r (T=Pd, It, Rh) in termetallic compounds are investigated by using powder x-ray diffraction and magnetic measurements. EuTrGa3-r crystallizes in orthorhombic structure with space group of Cmcm and Z = 4. There are four kinds of nonequivalent 4c crystal positions in EuTrGaa-r unit cell, which are occupied by 4Eu, 4GaⅠ, 4(GaⅡ, T) and 4GaⅢ, respectively. EuTrGa3-r ex- hibits the complex magnetic states in low-temperature regime, with the three-, two- and one-antiferromagnetic transitions occurring for T=Ir, T=Rh and T=Pd, respectively. It might be due to the Kondo effect: a localized antiferromagnetic interaction of the isolated impurity spins with the surrounding conduction electrons at low-temperature regime.
基金supported by the Guangxi Provincial Department of Education(No.KY2015ZD130,YB2014414)the Natural Science Foundation of Guangxi Province(No.2014GXNSFBA118040)+2 种基金The supports of the National Natural Science Foundation of China(No.51402158)are gratefully acknowledgedthe financial support by the Opening Project of Guangxi Colleges and Universities Key Laboratory of Beibu Gulf Oil and Natural Gas Resource Effective Utilization(No.2015KLOG09)the financial support from the Natural Science Foundation of Qinzhou University(No.2014PY-GJ05)
文摘A new 3-D nickel(Ⅱ) metal-organic framework(MOFs) with formula [Ni(bib)_2(SO_4)]_n(1), where bib = 1,4-bis(imidazol-1-yl)benzene, has been synthesized and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and surface photovoltage spectroscopy(SPS). Complex 1 crystallizes in monoclinic system, space group C2/c with a = 19.5988(6), b = 9.7531(3), c = 11.8146(4) ?, β = 96.185(3)°, V = 2245.20(12) ?~3, C_(24)H_(20)N_8NiO_4S, M_r = 575.25, D_c = 1.702 g/cm^3, Z = 4, F(000) = 1184, μ = 1.011 mm-1, the final R = 0.0293 and w R = 0.0702. X-ray diffraction analyses indicated that the center Ni^(2+) ion is six-coordinated with an O_2N_4 donor set of two μ_2-SO_4^(2–) and four bib ligands, resulting in an ideal octahedral geometry. Topological analysis on complex 1 considers each Ni^(2+) as a 6-connected node, while bib and sulfate ion as linkers, giving an α-Po topology with short Schl?fli symbol 412·63. In the crystal packing, the components interact with pairs of intermolecular C–H×××O hydrogen bonds. The SPS of 1 indicates that there are positive response bands in the range of 300~600 nm showing photo-electric conversion properties.
文摘In order to explore the impact relationship between intellectual property protection(IPP) system and technological innovation,a game model was constructed.The system of IPP is a set of game rules to protect the innovation under the background of R&D internationalization.Only when the main parties abide by the system of intellectual property,can the self-interest and collective interest of the two sides be maximized.The government must strengthen the penalties for intellectual property right(IPR) violations,reduce the cost of IPP declaration,reduce the cost of the innovator's own rights protection,and increase the cost of imitate behavior of IPR.
基金supported by Education Chamber of Henan Province(No.15A150068)
文摘A novel 3D metal-organic coordination polymer with helical chains based on a flexible 5-(imidazol-1-ylmethyl)isophthalic acid(H_2L) as a main ligand and 1,2-bis(4-pyridyl)ethane(bpa) as a N-containing ancillary ligand,[Cd L(bpa)_(0.5)]_n(1),has been obtained under hydrothermal conditions and characterized by elemental analysis,powder X-ray diffraction(PXRD),IR,thermal gravimetric analyses(TGA) and single-crystal X-ray diffraction.It crystallizes in monoclinic,space group P2_1/c with a = 10.984(2),b = 10.1829(12),c = 17.782(3) A,β = 123.156(11)o,V = 1665.1(5) A^3,Z = 4,Mr = 448.72,Dc = 1.790 g/cm^3,Rint = 0.0871,F(000) = 892,the final R = 0.0687 and w R = 0.1294 for 2920 observed reflections(I 〉 2σ(I)).In complex 1,the L^2- anions connect Cd(Ⅱ) ions to form two-dimensional metal-organic layers(Cd_2L_2)n,in which the 1D helical chains(Cd-L)_n are alternately arranged in a right-and left-handed sequence.These layers are further linked to build a 3D network by the bpa ligand.In addtion,photoluminescent properties for 1 are also investigated.
基金financially supported by the Department of Education of Liaoning Province of China
文摘Micro-nano structured Li Fe(1-x)MnxPO4/C(0≤x≤0.05)cathodes were prepared by spray drying,followed by calcination at 700°C.The spherical Li Fe(1-x)MnxPO4/C(0≤x≤0.05)particles with the size of 0.5 to5.0μm are composed of lots of nanoparticles of 20 to 30 nm,and have the well-developed interconnected pore structure.In contrast,when Mn doping content is 3 mol%(x=0.03),the Li Fe(0.97)Mn(0.03)PO4/C demonstrates maximum specific surface area of 31.30 m^2/g,more uniform pore size and relatively better electrochemical performance.The initial discharge capacities are 161.59,157.04 and 153.13 m Ah/g at a discharge rate of 0.2,0.5 and 1 C,respectively.Meanwhile,the discharge capacity retentions are~100%after 120 cycles.The improved electrochemical performance should be attributed to higher specific surface,smaller polarization voltage,and a high Li~+diffusion rate due to the micro-nano porous structure and lattice expansion produced by Mn doping.
基金Funded by the National Natural Science Foundation of China(Nos.21244006 and 50873013)the Beijing Natural Science Foundation(No.2182056)
文摘A simple non-isocyanate route synthesizing thermoplastic polyurethanes(TPUs) with good thermal and mechanical properties is described. Melt transurethane polycondensation of dimethyl 1,6-hexamethylene dicarbamate with 1,4-butanediol and 1,6-hexanediol was conducted at different molar ratios under the catalysis of tetrabutyl titanate. A series of crystallizable non-isocyanate TPUs with high molecular weight were prepared. The TPUs were characterized by gel permeation chromatography, FT-IR, 1 H-NMR, differential scanning calorimetry, thermogravimetric analysis, wide angle X-ray diffraction, AFM, and tensile tests. The TPUs exhibited Mn ranging from 12 500 to 26 400 g/mol, Mw from 16 700 to 56 400 g/mol, Tm up to 151.4 °C, and initial decomposition temperature over 241.8 °C. Their tensile strength reached 42.99 MPa with a strain at break of 30.00%. TPUs constructed simply with butylene, hexylene, and urethane linkages were successfully synthesized through a non-isocyanate route.
基金Supported by the Fundamental Research Funds for the Central Universities (Grant No.GK200901015)the Innovation Funds of Graduate Programs,SNU (Grant No.2009cxs028)
文摘In this note we study the property(ω1),a variant of Weyl's theorem by means of the single valued extension property,and establish for a bounded linear operator defined on a Banach space the necessary and sufficient condition for which property(ω1) holds.As a consequence of the main result,the stability of property(ω1) is discussed.
文摘Nanocrystalline hydroxyapatite (HA) powders have been synthesized by precipitation using Ca(NO3)2 4H2O and? (NH4)2 HPO4 at room temperature and atmospheric pressure. Nanocomposites of HA and partially stabilized zirconia (HA/PSZ) were sintered at atmospheric pressure and 1300 for 2h in air. The preparation techniques, structure and me- chanical properties of these materials were characterized. The addition of nanosized PSZ reinforcing phase to HA may lead to an improvement of the macro and micro mechanical properties and not affect its biocompatibility and bioactivity. The bending strength, fracture toughness and nano-hardness were near to or greater than those for human cortical bone and human tooth (dentine and enamel). The composite was incubated in a fresh human plasma which confirmed the bioactivity of nanosized HA/PSZ materials. The bonding reaction between HA/PSZ ceramic and the plasma proteins was found, and he- matopoietic cell phosphatase (HCP) layers formed on surface of each composite incubated in human plasma for two weeks. The diameter of a single HCP globule was less than 100 nm. Furthermore, the precipitating mechanism investigation was carried out through a comparative experiment in this paper.
基金Supported by the Fundamental Research Funds for the Central Universities(GK200901015)Project for Outstanding Young and Middle-aged Researchers initiated by Tianshui Normal University(TSY201205)
文摘In this note,property (ω)and property 1 (ω)are variants of Weyl’s theorem. By means of topological uniform descent, the sufficient and necessary conditions of a bounded linear operator defined on a Hilbert space that satisfies property 1 (ω) and property (ω)is studied. Moreover, property 1 (ω)and property (ω)of 2 2operator matrices are discussed as well.
基金Supported by the Fundamental Research Funds for the Central Universities(Grant No.GK201301007)National Natural Science Foundation of China(Grant No.11371012)
文摘Abstract A Hilbert space operator T is said to have property (ω1) if σα(T)/σaw(T) π00(T), where σα(T) andσαw(T) denote the approximate point spectrum and the Weyl essential approximate point spectrum of T respectively, and π00(T) ---- {λ∈ iso σ(T), 0 〈 dim N(T- λI) 〈 ∞}. Ifσα(T)/σαw(T) = π00(T), we say T satisfies property (w). In this note, we investigate the stability of the property (wi) and the property (w) under compact perturbations, and we characterize those operators for which the property (wi) and the property (w) are stable under compact perturbations.