Multifunctional metasurface:from extraordinary optical transmission to extraordinary optical diffraction in a single structure

We show that a metasurface composed of a subwavelength metallic slit array embedded in an asymmetric dielectric environment can exhibit either diffraction （EOD）. The cascaded refractive extraordinary optical transmission （EOT） or extraordinary optical indices of the dielectrics can leverage multiple decaying passages into variant subsections with different diffraction order combinations according to the diffraction order chart in the k-vector space, providing a flexible by changing the wavevector of the efficiencies can be enhanced to near or EOD in a single tional metasurface onstrated. Our findings incident light. As a result, either the unity by the excitation of the localized provide a convenient way components on a single planar device.

Effect of a single weak lithological structure on the height of a collapsing roof in a deep soft rock roadway

Besides the cross sections of roadways and the tendency and obliquity of roadway axes, the major controlling factors affecting the height of a collapsing roof include the weak lithological structure of surrounding rocks. This thesis analyzes the effect of two single and weak lithological structures of both sides and the roof on the height of a collapsing roof in a deep soft rock road- way. Using the two-dimensional UDEC3.1 software, a numerical structures of both sides of a roadway and of two weak lithological simulation was carried out on the models of weak lithological structures of roof of different depths. We reconstruct the overall processes from a break-away layer, bending, subsidence and the cracking of a collapsing roof. We also illustrate the distribution characteristics of displacement fields in the surrounding rock after the roof collapse in a deep soft rock roadway. The results of our numerical simulations indicate that the form of a roof collapse is side-expanding when the roadway is a weak structure at both sides The height of the roof collapse is related to the lithological combination of the roof when the roadway is a weak structure of the roof.

Au Microdisk-Size Dependence of Quantum Dot Emission from the Hybrid Metal-Distributed Bragg Reflector Structures Employed for Single Photon Sources

We investigate metallic microdisk-size dependence of quantum dot （QD） spontaneous emission rate and micro- antenna directional emission effect for the hybrid metM-distributed Bragg reflector structures based on a particular single QD emission. It is found that the measured photolumineseence （PL） intensity is very sensitive to the size of metMlic disk, showing an enhancement factor of 11 when the optimal disk diameter is 2μm and the numerical aperture of microscope objective NA=0.5. It is found that for large metal disks, the Purcell effect is dominant for enhanced PL intensity, whereas for small size disks the main contribution comes from plasmon scattering at the disk edge within the light cone collected by the microscope objective.

Neutron Diffraction Study on Structure of α－LiIO_3 Single Crystal under DC Voltage

A detailed investigation of anisotropy of neutron diffraction intensity enhancement observed in α-LiIO-3 single crystal under a DC field was carried out on a Four-Circle Neutron Diffractometer installed at the BR2 reactor in Belgium and CIAE reactor.It was found that the intensity increase must be ascribed to small displacements of oxygen and iodine atoms rather than the explanation which is only based on changes in the defect of the crystal structure,since the movement of lithium atom to interstitial sites or holes in the crystal may cause displacement of the other atoms.

Synthesis,Single-crystal Structure,and Computational Studies of a Yavapaiite Structure Compound:Pb(Sb0.5Fe0.5)(PO4)2

The single crystals and powder of a Yavapaiite Structure phosphate,namely,PbSb0.5Fe0.5（PO4）2,were synthesized by solid state method and characterized by X-ray single-crystal diffraction and powder diffraction.The title compound crystallizes in the monoclinic system,space group C2/c（No.15） with a = 16.716（4）,b = 5.186（7）,c = 8.130（2）A,β = 114.93（6）°,Z = 4,R（I 〉 2s（I）） = 0.0430,R indices（all data） = 0.0460,and T = 293（2） K.The title compound belongs to the Yavapaiite Structure A^（Ⅱ）M^（Ⅳ）（PO4）2 compounds,and the Sb1 atom and Fe1 atoms occupy the same site（M） and their occupancy factors are refined to be 0.5 and 0.5 having a sum occupancy factor of 1.0.Its structure consists of [M（PO）4]n^2n- layers running parallel to the（b,c） plane built up of cornerconnected MO6 octahedra and PO4 tetrahedra.Additionally,the calculations of energy band structure,and density of states have been performed with the density functional theory method.The studies of computational calculation and UV experimental results show that the new compound is an indirect band-gap insulator.

Morphologies and Structures of Perovskite Thin Film on Zn-face and O-face of ZnO Single Crystal

ZnO single crystal was used as the substrate to study the effect of ZnO crystal plane polarity on the morphology and structure of CH_3NH_3PbI_3（MAPbI_3） perovskite film and carrier transport properties,which is meaningful for improving ZnO-based perovskite solar cell. It is found that perovskite thin film has small grain size（about 190 nm） and high coverage rate on the O-face of ZnO single crystal,and the dominant exposed crystal plane of perovskite film is（110） plane. While the MAPbI_3 thin film has large grain size（about 1.03 μm） and low coverage rate on the Zn-face,and the（022） plane is dominantly exposed for the perovskite film. The injection of photogenerated electrons from MAPbI_3 film into the O-face of ZnO single crystal is faster and more effective than that to Zn-face. It is supposed that O-face is more suitable for ZnO single crystal based perovskite cell fabrication than Zn-face.

Precipitation of α Phase in the Massive and Feathery Structures in TiAl Alloys during Aging in the Single α Field

Precipitation of α-phase in massive and feathery microstructures was studied during aging in the single α field. It was found that the α-phase mainly precipitated along the γ-plate interfaces as laths in the feathery structure, while it nucleated at various sites in the massive structure in the form of particles and dominantly as plates. Precipitation of α-plates in the massive structure occurred by the difFusional ledge mechanism. The γm→α reaction proceeded by the growth of previously nucleated α-precipitates, and chiefly by the development of new α-plates

Structural Dependence of Creep/Fatigue Behaviour of Single Crystal Ni-base Superalloy

The effect of different initial microstructures deftned by γ' precipitate morphology has been investigated at the creep/fatigue conditions of 900℃ and 500 MPa. The wave form of stress as a function of time for cyclic load was of trapezoidal shape with a hold time of 10s at the upper stress level. The TEM was employed to examine the deformation process in strengthened γ' matrix in dependence of γ' precipitate morphology. The fracture lifetime and cycle number up to fracture were the criteria to evaluate the additional cyclic component efFect on the course of deformation

Reaction of (C_5H_5)_2NdCl·2LiCl with n-Butyllithium: Formation and Crystal Structure of [Li(DME)_3][(C_5H_5)_3Nd(μ-H)Nd(C_5H_5)_3]

The reaction of the THF solution of （C5H5）2NdCl· 2LiCl with n-butyllithium was studied and the neodymium hydride complex, [ Li （ DME ）3 ] [ （C5H5）3Nd （μ-H） Nd （ C5H5 ）3 ] 1 was isolated from the reaction solution. Complex 1 was crystallized from a mixture solvent of THF-DME and structurally characterized by single crystal X-ray diffraction method at - 80 ℃. The crystal is monoclinic, space group P21/c with unit cell dimensions a = 0.9670（2） nm, b =2.1001（5） nm, c=2.1279（7） nm, β=9.089（2）°, Z = 4. The structure was solved by heavy atom method and refined by the least-squares method to a final R = 0.094. The complex consists of disconnected ion pairs of [ Li （ DME ）3 ]^＋ and [ （ C5H5 ）3Nd （μ-H） Nd （C5H5）3]^-. The neodymium atom is coordinated by three η5-cyclopentadienyls, and two （C5H5）3Nd species are connected by one hydrogen bridge to form the anion with Nd-H 0.218（1） nm.

Synthesis and Structure of an Organo-templated Oxouranium Phosphite

A novel layered oxouranium phosphite open-structure [（C10H24N2）（H2O）][（UO2）2（HPO3）3]（denoted as TJPU-8,TJPU=Tianjin Polytechnic University） was hydrothermally synthesized with isophorondiamine（IPDA） as the template.Single crystal structure refinement disclosed that TJPU-8 crystallized in the monoclinic space group P21c with cell parameters a=1.8346（9） nm,b=0.6734（1） nm,c=2.0639（0） nm,β=114.61（5）°,V=2.3182（8） nm3,Z=2.TJPU-8 was constructed by UO7 monomer,U2O12 dimer and HPO3 groups.The monomeric UO7 or dimeric U2O12 was connected by HPO3 groups to form two types of 4-ring chains.An undulating sheet was then generated by connecting these two types of chains via HPO3 bridges.The layer structure formed by stacking the sheets along the a direction via the strong H-bonds of organoamine cations and water molecules intercalated in the interlayer spaces with the framework oxygen atoms.Although a mixture of cis-and trans-IPDA was used,only cis-IPDA served as the template.A typical green light emission of TJPU-8 is observed when excited by 266 nm laser.

Crystal and Molecular Structure of 4-Benzoyl-1,5-diphenyl-1H-pyrazole-3-carbonitrile

The crystal structure of potential active 4-benzoyl-1,5-diphenyl-1H*-pyrazole-3-carbonitrile (C23H15N3O) (I) has been determined from single crystal X-ray diffraction data. Also IR, Uv-vis and NMR spectral data were determined. The title compound crystallizes in the monoclinic space group P* 21/c, with a* = 9.3167(2), b* = 20.6677(3), c* = 10.6143(3) ?, β* = 112.665(3)°, V* = 1886.00(8) ?3, Dcalc* = 1.23g cm-3, Z* = 4. In the structure, intermolecular H*-bonds lead to the formation of a centrosymmetric dimmer of the molecule. Furthermore, the compound has a wide transmission window (300 to 1100 nm) with a transparency of nearly 100% and the UV cut-off wavelength occurs at 242 nm.

Syntheses，Structures and Properties of Some New Composition Perovskite Compounds：Sr0．6Bi0．4FeO2．7，Sr1－xBixFeO3－y and Ba1．5Pt0．5Mn2O6

New composition perovskite-type compounds with formula Sr0.6Bi0.4FeO2.7,Sr1-xBixFeO3-y(x=0.1 to 0. 9 in interveral of 0.1),and Ba1.5Pt0.5Mn2O6 have been synthsized and structurally characterized.The crystal structure of Sr0.6Bi0.4FeO2.7has been determined by X-ray single crystal diffraction,and the data of neutron powder diffraction collected at both room temperature and elevated temperature(380℃).The compound Sr0.6Bi0.4FeO2.7 crystallizes in the cubic space group of Pm3m with Z=1,a=3.9330(6) at room temperature,a=3.9498(6)A at 380℃.The magnetic structure from the neutron powder diffraction data collected at room temperature is consistent with a simple G-type antiferromagnetism and has a magnetic moment of 4.98 μB per Fe atom.The structures of Sr1-xBixFeO3-y with x other than 0.4 were also refined from the X-ray powder diffraction data.The data were consistent with a tetragonal cell when x=0.1,a rhombohedral cell when x= 0.9,and a cubic cell for x=0.2～0.8.From single crystal X-ray diffraction data,Ba1.5Pt0.5Mn2O6 crystallizes in hexagonal space group of P63mc with a= 5.7722 (6),c=4.4504(9),V=128.42(2),Z=1.The Sr(1-x)BixFeO(3-y)are found to be a good electronic and ionic conductor.

Molecular structure of imidazolate bridged binuclear zinc complex and its single crystal ESR spectra doped with bridged Cu—Zn complex

The X-ray crystal structure of [(dtma)ZnImZn(dtma)]ClO_4·2.5H_2O (Hdtma=4-Diethyl- enetriamineacetic acid) was determined.The crystal is of orthorhombic,space group Pbcn with a- 14.104(5),b=14.897(5),c=25.384(9),and Z=8.The least-square refinement of the structure leads to conventional R factor of 0.066.The magnetic properties of [(dtma)CulmZn(dtma)]CIO_4·2.5H_2O were investigated.From the single crystal ESR spectra of Zn—Im—Zn dimer doped with Cu—Im—Zn complex,the anisotropic g and A tensors and electronic spin-density of the Cu—Zn complex are obtained and the bonding nature of Cu is discussed.

Synthesis, Crystal Structures and Antioxidant Activities of 1,5-Diketone Derivatives

A new transition-metal-free protocol for the synthesis of polysubstituted 1,5-diketone derivatives from readily available starting materials has been developed.All the compounds were confirmed by HRMS,1H NMR and 13C NMR,and the single crystal structure of compound 4 f was determined to be of triclinic system,space group P1 with a=8.6515(8),b=8.6694(10),c=12.4985(8)?,b=102.152(6)°,V=895.43(15)?3,Dc=1.625 g/cm3,Z=2,F(000)=436,m(MoKα)=1.807 mm-1,R=0.0342 and w R=0.0691.Furthermore,the result of antioxidation test demonstrated that compound 4 a exhibited better antioxidant activity than butylated hydroxytoluene and vitamin C by the ABTS+radical cation decolorization assay.In addition,we further studied the mechanism of the transition-metal-free catalytic multicomponent domino reaction.

Crystal Structures and Characterizations of Bis(1-benzoyl-methyl-benzotriazole-N^3)dichoro Metal(II) Complex:[MCl_2-(C_6H_4N_3CH_2COPh)_2][M=Zn(II),Co(II)]

The structures of [MCl2(C6H4N3CH2COPh)2] [M=Zn(II) (1), Co(II) (2)] have been determined by X-ray crys-tallography. They were characterized by elemental analysis, IR spectrum, electronic spectrum and thermogravimet-ric-differential thermal analysis. They all crystallize in the triclinic system, space group P? with lattice parameters a=0.9449(2) nm, b=1.1291(2) nm, c=1.3637(3) nm, a=111.70(3)o, b=94.33(3)o, =90.97(3), Z=2 for com-pound 1; a=0.9437(2) nm, b=1.1277(2) nm, c=1.3650(3) nm, =111.76(3)o, =94.50(3)o, =90.80(3)o, Z=2 for compound 2. The metal ions are all coordinated by two Cl- anions and two nitrogen atoms of 1-benzoylmethyl-benzotriazole ligands, forming the distorted tetrahedral geometry. The ZnCl and ZnN bond lengths are 0.2209(2), 0.2210(2) nm and 0.2059(4), 0.2067(4) nm, respectively. The CoCl and CoN bond lengths are 0.2215(2), 0.2222(2) nm and 0.2028(5), 0.2045(5) nm, respectively. The thermogravimetric (TG) data indicate that they are nearly similar in TG curve, and there are not structural transitions in the two compounds. They all have a high thermal stability. But, there is little difference in DTG (differential thermogravimetric) curves of those two compounds. Elemental analysis, electronic and IR spectra are in agreement with the structural data.

Copper（II） Complexes Based on 4＇-R-Terpyridine： Synthesis, Structures, and Photocatalytic Properties

Complexes Cu（II）（4＇-R-terpyridine）2（C104）2[R=2-thienyl（1）, 2-（5-bromothienyl）（2）, 2-（5-methyl- thienyl）（3） and 2-（5-methoxythienyl）（4）] were synthesized, and their structures were determined by single-crystal X-ray diffraction analyses and were further characterized by high resolution mass spectrometry, infrared spectrosco- py（m）, as well as elemental analysis. Single crystal X-ray diffraction analysis shows that Cu（II） ions in the complexes are both six-coordinated with N6 coordination sphere, displaying distorted octahedral geometries. In addition, the UV-Vis absorption spectra show that the four complexes all exhibit absorption components in both UV and visible light regions. Thus, the photocatalytic activities of the four complexes in the degradation of organic dyes were investigated.

Investigations on Preparation,Crystal Structure and Thermal Stability of Bis(O-ethylcarbonodithiolato-S,S′)(1,10-phenanthroline-N^1,N^(10))cobalt(II) Complex:[Co(Et-XA)_2·phen]·H_2O (XA=xanthate)

[Co(Et XA) 2·phen]·H 2O was prepared by adding 1,10 phen^anthroline to the EtOH solution of bis( O ethylcarbo^no^di^thio^lato)cobalt(II) [Co(Et XA) 2]. The single crystal structure has been determined by X ray diffraction analysis. The compound is orthorhombic with space group Pna 2 1 and unit cell parameters a =1 0290(2) nm, b =1 4550(3) nm and c =1 4860(3) nm. The geometry of each Co atom which coordinates with four S atoms from two xanthate anions and two N atoms from phenanthroline ligand, is a distorted octahedron. The brown crystals were examined by elemental analysis, FT IR, UV spectra and thermogravimetric differential thermal analysis (TG DTA). Thermal decomposition of the compound takes place in several steps. In the first step, the compound releases 1,10 phenanthroline ligand, then loses the H 2O molecules. In the second step, the complex decomposes to CoS 3. The final product of thermal decomposition is CoS. Elemental analysis, IR and UV spectra are in agreement with the proposd structure.

Structure of Tetra[β-(1,2,4-triazole-1-yl)propiophenone] Dichloro Nickel(II) Solvate Hexahydrate Complex: [NiCl_2(C_2H_2N_3CH_2CH_2COPh)_4]·6H_2O

The mononuclear complex, [NiCl 2(trzCH 2CH 2COPh) 4]·6H 2O (trz=1,2,4-triazole), was synthesized and its structure was determined by single crystal X-ray determination. It crystallizes in the monoclinic system, space group P2 1/c, with lattice parameters: a= 0.80391(2) nm, b= 1.08215(2) nm, c=2.90133(2) nm, β=94.792 (1)° and Z=2. Each nickel atom is coordinated by four N atoms of triazole from four β-(1,2,4-triazole-1-yl)propiophenone ligands and two chloride anions in trans arrangement with octahedral coordination geometry. In addition to the coordinating nickel complex, there are six uncoordinated water molecules. The Ni-Cl distance is 0.24865(8) nm and the Ni-N distances are in the range of 0.2072(2) to 0.2099(2) nm, respectively. In the solid state, the title compound forms three dimensional network structure through hydrogen bonds. The intermolecular hydrogen bonds connect the [NiCl 2(C 2H 2N 3CH 2CH 2COPh) 4] and H 2O moieties. The deep green crystals were also examined by elemental analysis, FT-IR and UV spectra, which are in agreement with the structural data.

Synthesis,crystal structures and complexing ability of difunctionalized copillar[5]arene Schiff bases

An efficient method for the synthesis of some difunctionalized copillar[5]arene Schiff bases from condensation of salicylaldehyde and its 5-chloro,5-bromo,3,5-di（t-butyl） substituted derivatives with corresponding diamino-functionalized copillar[5]arene,which were prepared by Gabriel reaction according to the reported method.Single-crystals of six copillar[5]arenes were determined by X-ray diffraction.An ORTEP of compounds showed that the two chains units of Schiff base exist in the outside of the cavity of pillar[5]arene.Furthermore,the complexing ability of these Schiff bases to transition metal ions were investigated by UV and fluorescence spectroscopy.

Quantification of disaster resilience in civil engineering:A review

Resistance to unexpected disasters and rapid post-disaster recovery(i.e.,disaster resilience)of cities are extremely necessary owing to the concentrated risk of urbanization.Resilience quantification can adequately reflect the capacity of a city to withstand disasters.Many existing studies have focused on and proposed several frameworks on the quantitative measures of disaster resilience,and the corresponding research objects include different types of disasters(e.g.,earthquake,hurricane,flood,and fire),various domains(e.g.,engineering,social,and economic),and multiple levels(e.g.,city,community,and building).Among these research objects,studies on seismic resilience in civil engineering are relatively comprehensive.Specifically,studies on resilience in civil engineering have paid significant attention to the dynamics of engineering facilities and the engineering-related social and economic functions,including city-scale engineering,social,and economic functionalities,and essential functionalities of building,transportation,lifeline,and nonphysical subsystems of a city.Consequently,based on the review of resilience studies carried out in recent years,the framework and specifications for the quantification of disaster resilience of civil engineering systems subjected to earthquakes and other unexpected disasters are elaborated.Methods of disaster resilience assessment of cities and the corresponding subsystems are discussed.Furthermore,several case studies are reviewed,and resilience limit-state analyses of communities and buildings are performed.