Condition transfer between prestressed bridges using structural state translation for structural health monitoring

Implementing Structural Health Monitoring(SHM)systems with extensive sensing layouts on all civil structures is obviously expensive and unfeasible.Thus,estimating the state(condition)of dissimilar civil structures based on the information collected from other structures is regarded as a useful and essential way.For this purpose,Structural State Translation(SST)has been recently proposed to predict the response data of civil structures based on the information acquired from a dissimilar structure.This study uses the SST methodology to translate the state of one bridge(Bridge#1)to a new state based on the knowledge acquired from a structurally dissimilar bridge(Bridge#2).Specifically,the Domain-Generalized Cycle-Generative(DGCG)model is trained in the Domain Generalization learning approach on two distinct data domains obtained from Bridge#1;the bridges have two different conditions:State-H and State-D.Then,the model is used to generalize and transfer the knowledge on Bridge#1 to Bridge#2.In doing so,DGCG translates the state of Bridge#2 to the state that the model has learned after being trained.In one scenario,Bridge#2’s State-H is translated to State-D;in another scenario,Bridge#2’s State-D is translated to State-H.The translated bridge states are then compared with the real ones via modal identifiers and mean magnitude-squared coherence(MMSC),showing that the translated states are remarkably similar to the real ones.For instance,the modes of the translated and real bridge states are similar,with the maximum frequency difference of 1.12%and the minimum correlation of 0.923 in Modal Assurance Criterion values,as well as the minimum of 0.947 in Average MMSC values.In conclusion,this study demonstrates that SST is a promising methodology for research with data scarcity and population-based structural health monitoring(PBSHM).In addition,a critical discussion about the methodology adopted in this study is also offered to address some related concerns.

Digital image correlation-based structural state detection through deep learning

This paper presents a new approach for automatical classification of structural state through deep learning.In this work,a Convolutional Neural Network(CNN)was designed to fuse both the feature extraction and classification blocks into an intelligent and compact learning system and detect the structural state of a steel frame;the input was a series of vibration signals,and the output was a structural state.The digital image correlation(DIC)technology was utilized to collect vibration information of an actual steel frame,and subsequently,the raw signals,without further pre-processing,were directly utilized as the CNN samples.The results show that CNN can achieve 99%classification accuracy for the research model.Besides,compared with the backpropagation neural network(BPNN),the CNN had an accuracy similar to that of the BPNN,but it only consumes 19%of the training time.The outputs of the convolution and pooling layers were visually displayed and discussed as well.It is demonstrated that:1)the CNN can extract the structural state information from the vibration signals and classify them;2)the detection and computational performance of the CNN for the incomplete data are better than that of the BPNN;3)the CNN has better anti-noise ability.

Charge Density Wave States and Structural Transition in Layered Chalcogenide TaSe_(2-x)Te_x

The structural features and three-dimensional nature of the charge density wave （CDW） state of the layered chalcogenide 1T-TaSe2-xTex （0≤x≤2.0） are characterized by Cs-corrected transmission electron microscopy measurements. Notable changes of both average structure and the CDW state arising from Te substitution for Se are clearly demonstrated in samples with x〉0.3. The commensurate CDW state characterized by the known star-of-David clustering in the 1T-TaSe2 crystal becomes visibly unstable with Te substitution and vanishes when x=0.3. The 1T-TaSe2-xTex （0.3≤x≤1.3） samples generally adopt a remarkable incommensurate CDW state with monoclinic distortion, which could be fundamentally in correlation with the strong qq-dependent electron-phonon coupling-induced period-lattice-distortion as identified in TaTe22. Systematic analysis demonstrates that the occurrence of superconductivity is related to the suppression of the commensurate CDW phase and the presence of discommensuration is an evident structural feature observed in the superconducting samples.

THE WAY FOR STATE FOREIGN TRADE ENTERPRISES TO ADOPT STRUCTURAL REFORM

The Sichuan Provincial ChangjiangEnterprise Company, the former ofSichuan Provincial ChangjiangEnterprise (Group) Holdings Co.(SPCEGHC), is a comprehensive foreigntrade enterprise under the direct leadershipof the provincial government, mainly engagedin various kinds of foreign trade businessand as an agent for clients, involving deliveryof goods to foreign countries, the exchangeof technology, and the repair and leasing ofdomestic equipment. It was restructured tobecome an enterprise group in 1988, a"window" corporation on the province.

Resonance Raman Spectroscopic and Theoretical Study of Geometry Distortion of Thiourea in 2^1A State

The A-band resonance Raman spectra of thiourea were obtained in water and acetonitrile solution. B3LYP/6-311＋＋G（3df,3pd） and RCIS/6-311＋＋G（3df,3pd） calculations were done to elucidate the ultraviolet electronic transitions, the distorted geometry structure and the saddle point of thiourea in 21A excited state, respectively. The resonance Raman spectra were assigned. The absorption spectrum and resonance Raman intensities were modeled using Heller＇s time-dependent wavepacket approach to resonance Raman scattering. The results indicate that largest change in the displacement takes place with the C--S stretch mode u6 （｜△｜=0.95） and noticeable changes appear in the H5N3H6＋H8N4H7 wag v5 （｜△｜=0.19）, NCN symmetric stretch^-C--S stretch＋N3H6＋H8N4 wag v4 （｜△｜=0.18）, while the moderate intensities of 2-15 and 4-15 are mostly due to the large excited state frequency changes of v15, but not due to its significant change in the normal mode displacement. The mechanism of the appearance of even overtones of the S-CN2 out of plane deformation is explored. The results indicate that a Franck-Condon region saddle point is the driving force for the quadric phonon mechanism within the standard A-term of resonance Raman scattering, which leads to the pyramidalization of the carbon center and the geometry distortion of thiourea molecule in 21A excited state.

Theoretical Study of Geometric Structures for Ground-state Al_nC(n=2-7) Clusters

With the aid of the molecular orbital DMol3 program,the energetics and electronic structures of several AlnC（n = 2-7） configurations have been searched and calculated by improved minimum energy paths（MEPs） by setting ＂imaging product＂.A new high symmetry,supervalence isomer of Al5C cluster,i.e.,D5h-Al5C,at the local minimum in the MEPs is detected.Several parameters,such as binding energy,HOMO-LUMO energy gap,vertical electron detachment energy and electron affinity energy,are calculated to characterize and evaluate the stability of three Al5C configurations,i.e.,D5h-Al5C,Cs-Al5C and C1-Al5C.The results show that the D5h-Al5C cluster is the ground state structure instead of Cs-Al5C.Due to the formation of many central σ bonds after polymerizing for D5h-Al5C,the decrease of the energy for HOMO orbit results in more territory for HOMO electrons of dislocation effect,then the energy difference between HOMO and LUMO is increasing to enhance the stability of molecules to produce such supervalence structure of Al5C cluster.The configuration evolution between D5h-Al5C,Cs-Al5C and C1-Al5C and the synthesis preference in the mode of Al5 ＋ C → Al5C reveals that the Cs-Al5C and C1-Al5C con-figurations are permissive to coexist with D5h-Al5C structure in energetics.

NON-EQUILIBRIUM STATIONARY STATE IN CHEMICAL REACTION OF SiO_2/Fe AT INTERFACE OF SLAG/METAL AND ITS STABILITY DURING ARC WELDING

For characteristics of open and far from thermodynamic equilibrium in welding chemical reaction, a new kind of quantitative method, which is used to analyze direction and extent for chemical reaction of SiO2/Fe during quasi-steady state period, is introduced with the concept of non-equilibrium stationary state. The main idea is based on thermodynamic driving forces, which result in non-zero thermodynamic fluxes and lead to chemical reaction far away from thermodynamic equilibrium. There exists certain dynamic equilibrium relationship between rates of diffusion fluxes in liquid phase of reactants or products and the rate equation of chemical reaction when welding is in quasi-steady state. As result of this, a group of non-linear equations containing concentrations of all substances at interface of slag/liquid-metal may be established. Moreover the stability of this non-equilibrium stationary state is discussed using dissipative structure theory and it is concluded theoretically that this non-equilibrium stationary state for welding chemical reaction is of stability.

Density functional investigation on structural and electronic properties of small bimetallic Pb_(n)Ag_(n)(n=2–12)clusters

Structural and electronic properties of PbnAgn(n=2–12)clusters were investigated by density functional theory with generalized gradient approximation at BLYP level in DMol3 program package.The optimized bimetallic PbnAgn(n=2–12)clusters were viewed as the initial structures,then,those were calculated by ab initio molecular dynamics(AIMD)to search possible global minimum energy structures of PbnAgn clusters,finally,the ground state structures of PbnAgn(n=2–12)clusters were achieved.According to the structural evolution of lowest energy structures,Ag atoms prefer gather in the central sites while Pb atoms prefer external positions in PbnAgn(n=2–12)clusters,which is in excellent agreement with experimental results from literature and the application in metallurgy.The average binding energies,HOMO-LUMO gaps,vertical ionization potentials,vertical electron affinities,chemical hardnessη,HOMO orbits,LUMO orbits and density of states of PbnAgn(n=2–12)clusters were calculated.The results indicate that the values of HOMO-LUMO gaps,vertical ionization potentials,vertical electron affinities and chemical hardnessηshow obvious odd-even oscillations when n≤5,PbnAgn(n=2–12)clusters become less chemically stable and show insulator-to-metal transition with the variation of cluster size n,PbnAgn(n≥9)cluster are good candidates to study the properties of PbAg alloys.Those can be well explained by the density of states(DOS)distributions of Pb atoms and Ag atoms between–0.5 Ha and 0.25 Ha in PbnAgn(n=2–12)clusters.

GGA+U study of the electronic energy bands and state density of the wurtzite In_(1-x)Ga_xN

The electronic band structures, densities of states （DOSs）, and projected densities of states （PDOSs） of the wurtzite In1-xGaxN with x=0, 0.0625, 0.125 are studied using the generalized-gradient approximation （GGA） and GGA＋U in density functional theory. Our calculations suggest that in the case of wurtzite InN it is important to apply an on-site Hubbard correction to both the d states of indium and the p states of nitrogen in order to recover the correct energy level symmetry and obtain a reliable description of the InN band structure. The method is used to study the electronic properties of the wurtzite In1-xGaxN. The conduction band minimum （CBM） energy increases, while the valence band maximum （VBM） energy decreases with the increase of the gallium concentration. The effect leads to broadening the band gap （BG） and the valence band width （VBW）. Furthermore, the compressive strain in the crystal can cause the BG and the VBW to increase with the increase of gallium concentrations.

Characterization of Interface State Density of Ni/p-GaN Structures by Capacitance/Conductance-Voltage-Frequency Measurements

For the frequency range of I kHz-lOMHz, the interface state density of Ni contacts on p-GaN is studied using capacitance-voltage （C-V） and conductance-frequency-voltage （G-f-V） measurements at room temperature. To obtain the real capacitance and interface state density of the Ni/p-GaN structures, the effects of the series resistance （Rs） on high-frequency （SMHz） capacitance values measured at a reverse and a forward bias are investigated. The mean interface state densities obtained from the CHF-CLF capacitance and the conductance method are 2 ×1012 e V-1 cm-2 and 0.94 × 1012 eV-1 cm-2, respectively. Furthermore, the interface state density derived from the conductance method is higher than that reported from the Ni/n-GaN in the literature, which is ascribed to a poor crystal quality and to a large defect density of the Mg-doped p-GaN.

Calculation of the structural properties of a strange quark star in the presence of a strong magnetic field using a density dependent bag constant

We have calculated the structural properties of a strange quark star with a static model in the presence of a strong magnetic field. To this end, we use the MIT bag model with a density dependent bag constant. To parameterize the density dependence of the bag constant, we have used our results for the lowest order constrained variational calculation of the asymmetric nuclear matter. By calculating the equation of state of strange quark matter, we have shown that the pressure of this system increases by increasing both density and magnetic field. Finally, we have investigated the effect of density dependence of the bag constant on the structural properties of a strange quark star.

THE INFLUENCE OF HEAT TREATMENT ON STRUCTURES OF THE AGGREGATED STATE OF POLYAMIDE-1010

The structural parameters of the aggregated state of polyamide (PA)-1010 annealed at various temperatures were computed by means of the desmearing intensity from Smalt Angle X-ray Scattering (SAXS) measurements and by using the concept of the distance distribution function. The results indicated that the structural parameters of the aggregated state were strongly dependent upon heat treatment conditions and the maximum values of the structural parameters were obtained for the samples annealed at T = 175 degrees C. The particle size Z annealed at different temperature was ranged between 8.1-12.8nm, and the values of the distance distribution function P-max(Z) were obtained when Z = 4.0-6.8 nm. Using one dimension electron density correlation function (1D EDCF) method long period (L) and thickness of the lamellar (d(0)) were estimated and were found to increase with the increase of the degree of crystallinity.

Investigation of the Short-Time Photodissociation Dynamics of Furfural in S2 State by Resonance Raman and Quantum Chemistry Calculations

Raman(resonance Raman,FT-Raman),IR and UV-visible spectroscopy and quantum chemistry calculations were used to investigate the photodissociation dynamics of furfural in S2 state.The resonance Raman(RR)spectra indicate that the photorelaxation dynamics for the S0→S2 excited state is predominantly along nine motions:C=O stretchν5(1667 cm-1),ring C=C antisymmetric stretchν6(1570 cm-1),ring C=C symmetric stretchν7(1472 cm-1),C2-O6-C5 symmetric stretch/C1-H8 rock in planeν8(1389 cm-1),C3-C4 stretch/C1-H8 rock in planeν9(1370 cm-1),C5-O6 stretch in planeν12(1154 cm-1),ring breathν13(1077 cm-1),C3-C4 stretchν14(1020 cm-1),C3-C2-O6 symmetric stretchν16(928 cm-1).Stable structures of S0,S1,S2,T1 and T2 states with Cs point group were optimized at CASSCF method in Franck-Condon region there are S2/S1 conical intersection was found by state average method and RR spectra.

Quantum Chemical Study on the Structural Characteristics and Stability of AlS_n~± Clusters

The geometric configurations and electronic structures of AlSn ±（n = 1~10） clusters were studied by the B3LYP（DFT） method at the 6-311G＊＊ level. The changing rules of the ground state structure features, charge transfer and bonding characteristics of the aluminum-sulfur doped clusters were discussed in detail. The ground states of AlSn ±（n 〉 2） are all AlcoreSshell planar or solid double ring structures formed by inserting one Al atom to the Sm and Sn-m（m

Band structure and edge states of star-like zigzag graphene nanoribbons

Connecting three zigzag graphene nanoribbons（ZGNRs） together through the sp^3 hybrid bonds forms a star-like ZGNR（S-ZGNR）. Its band structure shows that there are four edge states at k = 0.5, in which the three electrons distribute at three outside edge sites, and the last electron is shared equally（50%） by two sites near the central site. The lowest conductance step in the valley is 2, two times higher than that of monolayer ZGNR（M-ZGNR）. Furthermore, in one quasithree-dimensional hexagonal lattice built, both of the Dirac points and the zero-energy states appear in the band structure along the z-axis for the fixed zero k-point in the x-y plane. In addition, it is an insulator in the x-y plane due to band gap 4 eV, however, for any k-point in the x-y plane the zero-energy states always exist at kz = 0.5.

THE STRUCTURE OF AGGREGATION STATE AND ISOTHERMAL CRYSTALLIZATION KINETICS OF NYLON-1010

The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD, DSE, Variance-Range Function and density measurement. The results show that crystallization of Nylon-1010 has the most suitable annealing temperature, the crystals of the Nxlon-1010 are two-dimension heterogeneous nucleation. Both low treatment temperature and high crystallization te, temperature are disadvantageous for Nylon-1010 crystal growth.

Structural,electronic and elastic properties of YCu from first principles

The structural, electronic and elastic properties of YCu compound in the B2 （CsCl） phase were investigated using the density functional theory （DFT） within the generalized gradient approximation （GGA）. The electronic density of states （DOS） obtained in this way accorded weU with the results of a recent study utilizing the full-potential linearized augmented plane wave （FLAPW） method. We also found that the density of d-states at the Fermi energy was low. The calculated equilibrium properties such as lattice constant, bulk modulus and its first derivative, and the elastic constants were in good agreement with experimental and theoretical results.

First-principles calculations of structural and electronic properties of Tl_xGa_(1-x)As alloys

The zincblende ternary alloys Tl_xGa_（1-x） As（0 〈 x 〈 1） are studied by numerical analysis based on the plane wave pseudopotential method within the density functional theory and the local density approximation. To model the alloys,16-atom supercells with the 2 × 2 × 2 dimensions are used and the dependency of the lattice parameter, bulk modulus,electronic structure, energy band gap, and optical bowing on the concentration x are analyzed. The results indicate that the ternary Tl_xGa_（1-x） As alloys have an average band gap bowing parameter of 4.48 eV for semiconductor alloys and 2.412 eV for semimetals. It is found that the band gap bowing strongly depends on composition and alloying a small Tl content with GaAs produces important modifications in the band structures of the alloys.

Correlation between Structures of Bulk Amorphous Zr-Ti-Ni-Cu-Be Alloy in Different States

The structures of the bulk amorphous Zr41Ti14Cu12.5Nil0.0Be22.5 alloy have been analyzed in solid, supercooled liquid and liquid with X-ray diffraction. The first coordination sphere radii and the first coordination numbers are 0.312 um, 11.2 in solid state.10.932 nm, 10.932 in supercooled liquid region and 0.305 urn, 11.296 in liquid state. The structures are the same in different states. But it shows some tendency to crystallizing that the first coordination sphere radius and the first coordination number drop in supercooled liquid region.

STUDIES ON SOLID STATE REACTIONS OF COORDINATION COMPOUNDS(LXⅡ)Solid state synthesis and crystal structure of the complex ICu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)CIJ·0.5CS_2

[Cu_(0.84)Au_(0.16)(PPh_3)_2(SC(Ph)NHPh)Cl]·0.5CS_2=,Mr=895.79,monoclinic,space group P2_1/a,a=17.231(3),b=14.611(2),c=18.000(3) ,β=105.56(2)°,V=4365(1) ~3, Z=4,D_c=1.37g/cm^3.,λ(MoK_α)=0.71073 ,μ=12.15cm^(-1),F(000)=1855,R=0.052, R_W=0.045 for 3930 observed reflections with Ⅰ>1.5σ(Ⅰ).The central metal atom has a dis. torted tetrahedral geometry with bond lengths Cu-S=2.384(2) (Au-S=2.389(4)), Cu-Cl=2.481(3)(Au-Cl=2.474(1))and Cu-P=2.269(2)-2.289(2)(Au-P=2.270(4)-2.279(4)) .