In this paper,numerical experiments are carried out to investigate the impact of penalty parameters in the numerical traces on the resonance errors of high-order multiscale discontinuous Galerkin(DG)methods(Dong et al...In this paper,numerical experiments are carried out to investigate the impact of penalty parameters in the numerical traces on the resonance errors of high-order multiscale discontinuous Galerkin(DG)methods(Dong et al.in J Sci Comput 66:321–345,2016;Dong and Wang in J Comput Appl Math 380:1–11,2020)for a one-dimensional stationary Schrödinger equation.Previous work showed that penalty parameters were required to be positive in error analysis,but the methods with zero penalty parameters worked fine in numerical simulations on coarse meshes.In this work,by performing extensive numerical experiments,we discover that zero penalty parameters lead to resonance errors in the multiscale DG methods,and taking positive penalty parameters can effectively reduce resonance errors and make the matrix in the global linear system have better condition numbers.展开更多
Searching for one-dimensional(1D)nanostructure with ferromagnetic(FM)half-metallicity is of significance for the development of miniature spintronic devices.Here,based on the first-principles calculations,we propose t...Searching for one-dimensional(1D)nanostructure with ferromagnetic(FM)half-metallicity is of significance for the development of miniature spintronic devices.Here,based on the first-principles calculations,we propose that the 1D CrN nanostructure is a FM half-metal,which can generate the fully spin-polarized current.The ab initio molecular dynamic simulation and the phonon spectrum calculation demonstrate that the 1D CrN nanostructure is thermodynamically stable.The partially occupied Cr-d orbitals endow the nanostructure with FM half-metallicity,in which the half-metallic gap(?s)reaches up to 1.58 eV.The ferromagnetism in the nanostructure is attributed to the superexchange interaction between the magnetic Cr atoms,and a sizable magnetocrystalline anisotropy energy(MAE)is obtained.Moreover,the transverse stretching of nanostructure can effectively modulate?s and MAE,accompanied by the preservation of half-metallicity.A nanocable is designed by encapsulating the CrN nanostructure with a BN nanotube,and the intriguing magnetic and electronic properties of the nanostructure are retained.These novel characteristics render the 1D CrN nanostructure as a compelling candidate for exploiting high-performance spintronic devices.展开更多
Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attr...Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.展开更多
By means of Muskhelishvili’s method and the technique of generalized conformal mapping,the physical plane problems are transformed into regular mathematical problems in quasicrystals(QCs).The analytical solution to a...By means of Muskhelishvili’s method and the technique of generalized conformal mapping,the physical plane problems are transformed into regular mathematical problems in quasicrystals(QCs).The analytical solution to an elliptical orifice problem with asymmetric cracks in one-dimensional(1D)orthorhombic QCs is obtained.By using the Dugdale-Barenblatt model,the plastic simulation at the crack tip of the elliptical orifice with asymmetric cracks in 1D orthorhombic QCs is performed.Finally,the size of the atomic cohesive force zone is determined precisely,and the size of the atomic cohesive force zone around the crack tip of an elliptical orifice with a single crack or two symmetric cracks is obtained.展开更多
Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of ci...Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.展开更多
The dynamical behavior of real-world phenomena is implausible graphically due to the complexity of mathematical coding. The present article has mainly focused on some one-dimensional real maps’ dynamical behavior irr...The dynamical behavior of real-world phenomena is implausible graphically due to the complexity of mathematical coding. The present article has mainly focused on some one-dimensional real maps’ dynamical behavior irrespective of using coding. In continuation, linear, quadratic, cubic, higher-order, exponential, logarithmic, and absolute value maps have been used to scrutinize their dynamical behavior, including the characteristics of the orbit of points. Dynamical programming software (DPS.exe) will be proposed as a new technique to ascertain the dynamical behavior of said maps. Thus, a mathematician can automatically determine one-dimensional real maps’ dynamical behavior apart from complicated programming code and analytical solutions.展开更多
In this paper,we investigate the interfacial behavior of a thin one-dimensional(1D)hexagonal quasicrystal(QC)film bonded on an elastic substrate subjected to a mismatch strain due to thermal variation.The contact inte...In this paper,we investigate the interfacial behavior of a thin one-dimensional(1D)hexagonal quasicrystal(QC)film bonded on an elastic substrate subjected to a mismatch strain due to thermal variation.The contact interface is assumed to be nonslipping,with both perfectly bonded and debonded boundary conditions.The Fourier transform technique is adopted to establish the integral equations in terms of interfacial shear stress,which are solved as a linear algebraic system by approximating the unknown phonon interfacial shear stress via the series expansion of the Chebyshev polynomials.The expressions are explicitly obtained for the phonon interfacial shear stress,internal normal stress,and stress intensity factors(SIFs).Finally,based on numerical calculations,we briefly discuss the effects of the material mismatch,the geometry of the QC film,and the debonded length and location on stresses and SIFs.展开更多
In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SP...In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SPH)method is developed using LS-DYNA software.The DEM and SPH are established on the same node to create common-node DEM-SPH particles,allowing for fluid–structure interactions.Numerical simulations of various scenarios,including water entry of a rigid sphere,dam-break propagation over wet beds,impact on an ice plate floating on water and ice accumulation on offshore structures,are conducted.The interaction between DS particles and SPH fluid and the crack generation mechanism and expansion characteristics of the ice plate under the interaction of structure and fluid are also studied.The results are compared with available data to verify the proposed coupling method.Notably,the simulation results demonstrated that controlling the cutoff pressure of internal SPH particles could effectively control particle splashing during ice crushing failure.展开更多
Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating fracture.An improved cracking strat...Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating fracture.An improved cracking strategy considering residual stress in the base bond SPH method was proposed to simulate failures in layered rocks and slopes and verified by experimental results and other simulation methods(i.e.,the discrete element method).Modified Mohr–Coulomb failure criterion was applied to distinguish the mixed failure of tensile and shear.Bond fracture markψwas introduced to improve the kernel function after tensile damage,and the calculation of residual stress after the damage was derived after shear damage.Numerical simulations were carried out to evaluate its performance under different stress and scale conditions and to verify its effectiveness in realistically reproducing crack initiation and propagation and coalescence,even fracture and separation.The results indicate that the improved cracking strategy precisely captures the fracture and failure pattern in layered rocks and rock slopes.The residual stress of brittle tock is correctly captured by the improved SPH method.The improved SPH method that considers residual strength shows an approximately 13%improvement in accuracy for the safety factor of anti-dip layered slopes compared to the method that does not consider residual strength,as validated against analytical solutions.We infer that the improved SPH method is effective and shows promise for applications to continuous and discontinuous rock masses.展开更多
The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grou...The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grouping videos.Grounded in the H.264 video coding standard,the algorithm first employs traditional robust watermark stitching technology to embed watermark information in the low-frequency coefficient domain of the U channel.Subsequently,it utilizes histogram migration techniques in the high-frequency coefficient domain of the U channel to embed auxiliary information,enabling successful watermark extraction and lossless recovery of the original video content.Experimental results demonstrate the algorithm’s strong imperceptibility,with each embedded frame in the experimental videos achieving a mean peak signal-to-noise ratio of 49.3830 dB and a mean structural similarity of 0.9996.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 7.59%and 0.4%on average.At the same time,the proposed algorithm has strong robustness to both offline and online attacks:In the face of offline attacks,the average normalized correlation coefficient between the extracted watermark and the original watermark is 0.9989,and the average bit error rate is 0.0089.In the face of online attacks,the normalized correlation coefficient between the extracted watermark and the original watermark is 0.8840,and the mean bit error rate is 0.2269.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 1.27%and 18.16%on average,highlighting the algorithm’s robustness.Furthermore,the algorithm exhibits low computational complexity,with the mean encoding and the mean decoding time differentials during experimental video processing being 3.934 and 2.273 s,respectively,underscoring its practical utility.展开更多
Predicting the response of liquefied natural gas(LNG)contained in vessels subjected to external waves is extremely important to ensure the safety of the transportation process.In this study,the coupled behavior due to...Predicting the response of liquefied natural gas(LNG)contained in vessels subjected to external waves is extremely important to ensure the safety of the transportation process.In this study,the coupled behavior due to ship motion and liquid tank sloshing has been simulated by the Smoothed-Particle Hydrodynamics(SPH)method.Firstly,the sloshing flow in a rectangular tank was simulated and the related loads were analyzed to verify and validate the accuracy of the present SPH solver.Then,a three-dimensional simplified LNG carrier model,including two prismatic liquid tanks and a wave tank,was introduced.Different conditions were examined corresponding to different wave lengths,wave heights,wave heading angles,and tank loading rates.Finally,the effects of liquid tank loading rate on LNG ship motions and sloshing loading were analyzed,thereby showing that the SPH method can effectively provide useful indications for the design of liquid cargo ships.展开更多
Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT<sub>1</sub> and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including func...Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT<sub>1</sub> and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including functioning as a growth factor, and as a contractile hormone, among others. The aim of this work was to examine the impact of Ang II on the expression and function of α<sub>1</sub>-adrenergic receptors (α<sub>1</sub>-ARs) in cultured rat aorta, and aorta-derived smooth muscle cells. Isolated Wistar rat aorta was incubated for 24 h in DMEM at 37˚C, then subjected to isometric tension and to the action of added norepinephrine, in concentration-response curves. Ang II was added (1 × 10<sup>−5</sup> M), and in some experiments, 5-Methylurapidil (α<sub>1A</sub>-AR antagonist), AH11110A (α<sub>1B</sub>-AR antagonist), or BMY-7378 (α<sub>1D</sub>-AR antagonist), were used to identify the α<sub>1</sub>-AR involved in the response. Desensitization of the contractile response to norepinephrine was observed due to incubation time, and by the Ang II action. α<sub>1D</sub>-AR was protected from desensitization by BMY-7378;while RS-100329 and prazosin partially mitigated desensitization. In another set of experiments, isolated aorta-derived smooth muscle cells were exposed to Ang II and α<sub>1</sub>-ARs proteins were evaluated. α<sub>1D</sub>-AR increased at 30 and 60 min post Ang II exposure, the α<sub>1A</sub>-AR diminished from 1 to 4 h, while α<sub>1B</sub>-AR remained unchanged over 24 h of Ang II exposure. Ang II induced an increase of α<sub>1D</sub>-AR at short times, and BMY-7378 protected α<sub>1D</sub>-AR from desensitization.展开更多
This article reviews the recent developments in the controlled growth of one-dimensional (1D) oxide nanomaterials, including ZnO, SnO2, In203, Ga203, SiOx, MgO, and Al203. The growth of 2D oxide nanomaterials was ca...This article reviews the recent developments in the controlled growth of one-dimensional (1D) oxide nanomaterials, including ZnO, SnO2, In203, Ga203, SiOx, MgO, and Al203. The growth of 2D oxide nanomaterials was carried out in a simple chemical vapor transport and condensation system. This article will begin with a survey of nanotechnology and 1D nanomaterials achieved by many researchers, and then mainly discuss on the controlled growth of ID oxide nanomaterials with their morphologies, sizes, compositions, and microstructures controlled by altering experimental parameters, such as the temperature at the source material and the substrate, temperature gradient in the tube furnace, the total reaction time, the heating rate of the furnace, the gas flow rate, and the starting material. Their roles in the formation of various morphologies are analyzed and discussed. Finally, this review will be concluded with personal perspectives on the future research directions of this area.展开更多
One-dimensional (1D) nanomaterials and nanostructures have received much attention due to their potential interest for understanding fundamental physical concepts and for applications in constructing nanoscale elect...One-dimensional (1D) nanomaterials and nanostructures have received much attention due to their potential interest for understanding fundamental physical concepts and for applications in constructing nanoscale electric and optoelectronic devices. Zinc sulfide (ZnS) is an important semiconductor compound of Ⅱ-Ⅵ group, and the synthesis of 1D ZnS nanomaterials and nanostructures has been of growing interest owing to their promising application in nanoscale optoelectronic devices. This paper reviews the recent progress on 1D ZnS nanomaterials and nanostructures, including nanowires, nanowire arrays, nanorods, nanobelts or nanoribbons, nanocables, and hierarchical nanostructures etc. This article begins with a survey of various methods that have been developed for generating 1D nanomaterials and nanostructures, and then mainly focuses on structures, synthesis, characterization, formation mechanisms and optical property tuning, and luminescence mechanisms of 1D ZnS nanomaterials and nanostructures. Finally, this review concludes with personal views towards future research on 1D ZnS nanomaterials and nanostructures.展开更多
Based on the fundamental equations of piezoelasticity of quasicrystal material,we investigated the interaction between a screw dislocation and a wedge-shaped crack in the piezoelectricity of one-dimensional hexagonal ...Based on the fundamental equations of piezoelasticity of quasicrystal material,we investigated the interaction between a screw dislocation and a wedge-shaped crack in the piezoelectricity of one-dimensional hexagonal quasicrystals.Explicit analytical solutions are obtained for stress and electric displacement intensity factors of the crack,as well as the force on dislocation.The derivation is based on the conformal mapping method and the perturbation technique.The influences of the wedge angle and dislocation location on the image force are also discussed.The results obtained in this paper can be fully reduced to some special cases already available or deriving new ones.展开更多
By constructing a new conformal mapping function, we study the surface effects on six edge nano-cracks emanating from a regular hexagonal nano-hole in one-dimensional (1D) hexagonal piezoelectric quasicrystals under a...By constructing a new conformal mapping function, we study the surface effects on six edge nano-cracks emanating from a regular hexagonal nano-hole in one-dimensional (1D) hexagonal piezoelectric quasicrystals under anti-plane shear. Based on the Gurtin–Murdoch surface/interface model and complex potential theory, the exact solutions of phonon field, phason field and electric field are obtained. The analytical solutions of the stress intensity factor of the phonon field, the stress intensity factor of the phason field, the electric displacement intensity factor and the energy release rate are given. The interaction effects of the nano-cracks and nano-hole on the stress intensity factor of the phonon field, the stress intensity factor of the phason field and the electric displacement intensity factor are discussed in numerical examples. It can be seen that the surface effect leads to the coupling of phonon field, phason field and electric field. With the decrease of cavity size, the influence of surface effect is more obvious.展开更多
One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, tran...One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy techniques. Results demonstrated that the hydrolysis of TBT had a great influence on the morphology of the coated TiO_2 shell, resulting in the formation of TiO_2 nanoparticles and nanolayer-modified Cd S@TiO_2 heterostructures. Degradation of methylene blue using Cd S@TiO_2 core-shell heterostructures as photocatalysts under visible light irradiation was investigated. Comparative photocatalytic tests showed that the TiO_2 nanoparticles-modified heterostructure exhibited a superior activity due to the passivity of photogenerated charge carriers.展开更多
Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solv...Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solved, and the exact analytic solutions of the stress intensity factors (SIFs) for mode Ⅲ problem are obtained. Under the limiting conditions, the present results reduce to the Griffith crack and many new results obtained as well, such as the circular hole with asymmetric collinear cracks, the elliptic hole with a straight crack, the mode T crack, the cross crack and so on. As far as the phonon field is concerned, these results, which play an important role in many practical and theoretical applications, are shown to be in good agreement with the classical results.展开更多
This paper presents an analytical solution of the one-dimensional consolidation in unsaturated soil with a finite thickness under vertical loading and confinements in the lateral directions. The boundary contains the ...This paper presents an analytical solution of the one-dimensional consolidation in unsaturated soil with a finite thickness under vertical loading and confinements in the lateral directions. The boundary contains the top surface permeable to water and air and the bottom impermeable to water and air. The analytical solution is for Fredlund's one-dimensional consolidation equation in unsaturated soils. The transfer relationship between the state vectors at top surface and any depth is obtained by using the Laplace transform and Cayley-Hamilton mathematical methods to the governing equations of water and air, Darcy's law and Fick's law. Excess pore-air pressure, excess pore-water pressure and settlement in the Laplace-transformed domain are obtained by using the Laplace transform with the initial conditions and boundary conditions. By performing inverse Laplace transforms, the analytical solutions are obtained in the time domain. A typical example illustrates the consolidation characteristics of unsaturated soil from an- alytical results. Finally, comparisons between the analytical solutions and results of the finite difference method indicate that the analytical solution is correct.展开更多
(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel t...(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel technique,and its transmission characteristics for photocatalysis were tested.The results show that the lattice constant,filling ratio,number of periodic layers,and incident angle had effects on the band gap.When the lattice constant,filling ratio,number of periodic layers,and incident angle were set to 125 nm,0.45,21,and 0°,respectively,a gap width of 53 nm appeared at the central wavelength(322 nm).The absorption peak of the photocatalyst at 357 nm overlapped the blue edge of the photonic band gap.A slow photon effect region above 96%reflectivity appeared.The degradation rate of tetracycline in(GO/TiO2)N photonic crystal was enhanced to 64%within 60 min.Meanwhile,the degradation efficiency of(GO/TiO2)N one-dimensional photonic crystal was effectively improved compared with those of the GO/TiO2 composite film and GO/TiO2 powder.展开更多
基金supported by the National Science Foundation grant DMS-1818998.
文摘In this paper,numerical experiments are carried out to investigate the impact of penalty parameters in the numerical traces on the resonance errors of high-order multiscale discontinuous Galerkin(DG)methods(Dong et al.in J Sci Comput 66:321–345,2016;Dong and Wang in J Comput Appl Math 380:1–11,2020)for a one-dimensional stationary Schrödinger equation.Previous work showed that penalty parameters were required to be positive in error analysis,but the methods with zero penalty parameters worked fine in numerical simulations on coarse meshes.In this work,by performing extensive numerical experiments,we discover that zero penalty parameters lead to resonance errors in the multiscale DG methods,and taking positive penalty parameters can effectively reduce resonance errors and make the matrix in the global linear system have better condition numbers.
基金the National Natural Science Foundation of China(Grant Nos.12004137,62071200,and 12104236)Shandong Provincial Natural Science Foundation of China(Grant Nos.ZR2020QA052,ZR2020ZD28,ZR2021MA040,and ZR2021MA060).
文摘Searching for one-dimensional(1D)nanostructure with ferromagnetic(FM)half-metallicity is of significance for the development of miniature spintronic devices.Here,based on the first-principles calculations,we propose that the 1D CrN nanostructure is a FM half-metal,which can generate the fully spin-polarized current.The ab initio molecular dynamic simulation and the phonon spectrum calculation demonstrate that the 1D CrN nanostructure is thermodynamically stable.The partially occupied Cr-d orbitals endow the nanostructure with FM half-metallicity,in which the half-metallic gap(?s)reaches up to 1.58 eV.The ferromagnetism in the nanostructure is attributed to the superexchange interaction between the magnetic Cr atoms,and a sizable magnetocrystalline anisotropy energy(MAE)is obtained.Moreover,the transverse stretching of nanostructure can effectively modulate?s and MAE,accompanied by the preservation of half-metallicity.A nanocable is designed by encapsulating the CrN nanostructure with a BN nanotube,and the intriguing magnetic and electronic properties of the nanostructure are retained.These novel characteristics render the 1D CrN nanostructure as a compelling candidate for exploiting high-performance spintronic devices.
基金the National Key Basic Research Program of China(Grant No.2022YFA1404800)the National Natural Science Foundation of China(Grant Nos.12234007 and 12221004)supported by Science and Technology Commission of Shanghai Municipality,China(Grant Nos.19XD1434600,2019SHZDZX01,19DZ2253000,20501110500,and 21DZ1101500)。
文摘Periodic photonic structures can provide rich modulation in propagation of light due to well-defined band structures.Especially near band edges,light localization and the effect of near-zero refractive index have attracted wide attention.However,the practically fabricated structures can only have finite size,i.e.,limited numbers of periods,leading to changes of the light propagation modulation compared with infinite structures.Here,we study the size effect on light localization and near-zero refractive-index propagation near band edges in one-dimensional periodic structures.Near edges of the band gap,as the structure's size shrinks,the broadening of the band gap and the weakening of the light localization are discovered.When the size is small,an added layer on the surface will perform large modulation in the group velocity.Near the degenerate point with Dirac-like dispersion,the zero-refractive-index effects like the zero-phase difference and near-unity transmittance retain as the size changes,while absolute group velocity fluctuates when the size shrinks.
基金Project supported by the National Natural Science Foundation of China(Nos.12162027 and 11962026)the Natural Science Key Project of Science and Technology Research in Higher Education Institutions of Inner Mongolia Autonomous Region(No.NJZZ22574)。
文摘By means of Muskhelishvili’s method and the technique of generalized conformal mapping,the physical plane problems are transformed into regular mathematical problems in quasicrystals(QCs).The analytical solution to an elliptical orifice problem with asymmetric cracks in one-dimensional(1D)orthorhombic QCs is obtained.By using the Dugdale-Barenblatt model,the plastic simulation at the crack tip of the elliptical orifice with asymmetric cracks in 1D orthorhombic QCs is performed.Finally,the size of the atomic cohesive force zone is determined precisely,and the size of the atomic cohesive force zone around the crack tip of an elliptical orifice with a single crack or two symmetric cracks is obtained.
基金Supported by National Natural Science Foundation of China(Grant Nos.52272433 and 11874110)Jiangsu Provincial Key R&D Program(Grant No.BE2021084)Technical Support Special Project of State Administration for Market Regulation(Grant No.2022YJ11).
文摘Ultrasonic guided wave is an attractive monitoring technique for large-scale structures but is vulnerable to changes in environmental and operational conditions(EOC),which are inevitable in the normal inspection of civil and mechanical structures.This paper thus presents a robust guided wave-based method for damage detection and localization under complex environmental conditions by singular value decomposition-based feature extraction and one-dimensional convolutional neural network(1D-CNN).After singular value decomposition-based feature extraction processing,a temporal robust damage index(TRDI)is extracted,and the effect of EOCs is well removed.Hence,even for the signals with a very large temperature-varying range and low signal-to-noise ratios(SNRs),the final damage detection and localization accuracy retain perfect 100%.Verifications are conducted on two different experimental datasets.The first dataset consists of guided wave signals collected from a thin aluminum plate with artificial noises,and the second is a publicly available experimental dataset of guided wave signals acquired on a composite plate with a temperature ranging from 20℃to 60℃.It is demonstrated that the proposed method can detect and localize the damage accurately and rapidly,showing great potential for application in complex and unknown EOC.
文摘The dynamical behavior of real-world phenomena is implausible graphically due to the complexity of mathematical coding. The present article has mainly focused on some one-dimensional real maps’ dynamical behavior irrespective of using coding. In continuation, linear, quadratic, cubic, higher-order, exponential, logarithmic, and absolute value maps have been used to scrutinize their dynamical behavior, including the characteristics of the orbit of points. Dynamical programming software (DPS.exe) will be proposed as a new technique to ascertain the dynamical behavior of said maps. Thus, a mathematician can automatically determine one-dimensional real maps’ dynamical behavior apart from complicated programming code and analytical solutions.
基金Project supported by the National Natural Science Foundation of China(Nos.11572289,1171407,11702252,and 11902293)the China Postdoctoral Science Foundation(No.2019M652563)。
文摘In this paper,we investigate the interfacial behavior of a thin one-dimensional(1D)hexagonal quasicrystal(QC)film bonded on an elastic substrate subjected to a mismatch strain due to thermal variation.The contact interface is assumed to be nonslipping,with both perfectly bonded and debonded boundary conditions.The Fourier transform technique is adopted to establish the integral equations in terms of interfacial shear stress,which are solved as a linear algebraic system by approximating the unknown phonon interfacial shear stress via the series expansion of the Chebyshev polynomials.The expressions are explicitly obtained for the phonon interfacial shear stress,internal normal stress,and stress intensity factors(SIFs).Finally,based on numerical calculations,we briefly discuss the effects of the material mismatch,the geometry of the QC film,and the debonded length and location on stresses and SIFs.
基金supported by the National Natural Science Foundation of China(Grant No.52201323).
文摘In this study,a common-node DEM-SPH coupling model based on the shared node method is proposed,and a fluid–structure coupling method using the common-node discrete element method-smoothed particle hydrodynamics(DS-SPH)method is developed using LS-DYNA software.The DEM and SPH are established on the same node to create common-node DEM-SPH particles,allowing for fluid–structure interactions.Numerical simulations of various scenarios,including water entry of a rigid sphere,dam-break propagation over wet beds,impact on an ice plate floating on water and ice accumulation on offshore structures,are conducted.The interaction between DS particles and SPH fluid and the crack generation mechanism and expansion characteristics of the ice plate under the interaction of structure and fluid are also studied.The results are compared with available data to verify the proposed coupling method.Notably,the simulation results demonstrated that controlling the cutoff pressure of internal SPH particles could effectively control particle splashing during ice crushing failure.
基金funded by the National Key Research and Development Program of China(Grant No.2023YFC3008300,Grant No.2019YFC1509702)the National Natural Science Foundation of China(Grant No.42172296).
文摘Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating fracture.An improved cracking strategy considering residual stress in the base bond SPH method was proposed to simulate failures in layered rocks and slopes and verified by experimental results and other simulation methods(i.e.,the discrete element method).Modified Mohr–Coulomb failure criterion was applied to distinguish the mixed failure of tensile and shear.Bond fracture markψwas introduced to improve the kernel function after tensile damage,and the calculation of residual stress after the damage was derived after shear damage.Numerical simulations were carried out to evaluate its performance under different stress and scale conditions and to verify its effectiveness in realistically reproducing crack initiation and propagation and coalescence,even fracture and separation.The results indicate that the improved cracking strategy precisely captures the fracture and failure pattern in layered rocks and rock slopes.The residual stress of brittle tock is correctly captured by the improved SPH method.The improved SPH method that considers residual strength shows an approximately 13%improvement in accuracy for the safety factor of anti-dip layered slopes compared to the method that does not consider residual strength,as validated against analytical solutions.We infer that the improved SPH method is effective and shows promise for applications to continuous and discontinuous rock masses.
基金supported in part by the National Natural Science Foundation of China under Grants 62202496,62272478the Basic Frontier Innovation Project of Engineering university of People Armed Police under Grants WJY202314,WJY202221.
文摘The proposed robust reversible watermarking algorithm addresses the compatibility challenges between robustness and reversibility in existing video watermarking techniques by leveraging scene smoothness for frame grouping videos.Grounded in the H.264 video coding standard,the algorithm first employs traditional robust watermark stitching technology to embed watermark information in the low-frequency coefficient domain of the U channel.Subsequently,it utilizes histogram migration techniques in the high-frequency coefficient domain of the U channel to embed auxiliary information,enabling successful watermark extraction and lossless recovery of the original video content.Experimental results demonstrate the algorithm’s strong imperceptibility,with each embedded frame in the experimental videos achieving a mean peak signal-to-noise ratio of 49.3830 dB and a mean structural similarity of 0.9996.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 7.59%and 0.4%on average.At the same time,the proposed algorithm has strong robustness to both offline and online attacks:In the face of offline attacks,the average normalized correlation coefficient between the extracted watermark and the original watermark is 0.9989,and the average bit error rate is 0.0089.In the face of online attacks,the normalized correlation coefficient between the extracted watermark and the original watermark is 0.8840,and the mean bit error rate is 0.2269.Compared with the three comparison algorithms,the performance of the two experimental indexes is improved by 1.27%and 18.16%on average,highlighting the algorithm’s robustness.Furthermore,the algorithm exhibits low computational complexity,with the mean encoding and the mean decoding time differentials during experimental video processing being 3.934 and 2.273 s,respectively,underscoring its practical utility.
基金the National Natural Science Foundation of China(No.52271316)the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515030262).
文摘Predicting the response of liquefied natural gas(LNG)contained in vessels subjected to external waves is extremely important to ensure the safety of the transportation process.In this study,the coupled behavior due to ship motion and liquid tank sloshing has been simulated by the Smoothed-Particle Hydrodynamics(SPH)method.Firstly,the sloshing flow in a rectangular tank was simulated and the related loads were analyzed to verify and validate the accuracy of the present SPH solver.Then,a three-dimensional simplified LNG carrier model,including two prismatic liquid tanks and a wave tank,was introduced.Different conditions were examined corresponding to different wave lengths,wave heights,wave heading angles,and tank loading rates.Finally,the effects of liquid tank loading rate on LNG ship motions and sloshing loading were analyzed,thereby showing that the SPH method can effectively provide useful indications for the design of liquid cargo ships.
文摘Angiotensin II (Ang II) is the main mediator of the Renin-Angiotensin-System acting on AT<sub>1</sub> and other AT receptors. It is regarded as a pleiotropic agent that induces many actions, including functioning as a growth factor, and as a contractile hormone, among others. The aim of this work was to examine the impact of Ang II on the expression and function of α<sub>1</sub>-adrenergic receptors (α<sub>1</sub>-ARs) in cultured rat aorta, and aorta-derived smooth muscle cells. Isolated Wistar rat aorta was incubated for 24 h in DMEM at 37˚C, then subjected to isometric tension and to the action of added norepinephrine, in concentration-response curves. Ang II was added (1 × 10<sup>−5</sup> M), and in some experiments, 5-Methylurapidil (α<sub>1A</sub>-AR antagonist), AH11110A (α<sub>1B</sub>-AR antagonist), or BMY-7378 (α<sub>1D</sub>-AR antagonist), were used to identify the α<sub>1</sub>-AR involved in the response. Desensitization of the contractile response to norepinephrine was observed due to incubation time, and by the Ang II action. α<sub>1D</sub>-AR was protected from desensitization by BMY-7378;while RS-100329 and prazosin partially mitigated desensitization. In another set of experiments, isolated aorta-derived smooth muscle cells were exposed to Ang II and α<sub>1</sub>-ARs proteins were evaluated. α<sub>1D</sub>-AR increased at 30 and 60 min post Ang II exposure, the α<sub>1A</sub>-AR diminished from 1 to 4 h, while α<sub>1B</sub>-AR remained unchanged over 24 h of Ang II exposure. Ang II induced an increase of α<sub>1D</sub>-AR at short times, and BMY-7378 protected α<sub>1D</sub>-AR from desensitization.
基金The authors acknowledge the support from the National Major Project of Fundamental Research:Nanomaterials and Nanostructures(Grant No.2005CB623603)the National Natural Science Foundation of China(Grant No.10304018,10574131)the Special Fund for President Scholarship,Chinese Academy of Sciences.We also thank Dr.Liang LI,Prof.Changhui YE,Dr.Yufeng HA0,Dr.Xinsheng PENG,Dr.Shuhui SUN,Dr.Changhao LIANG,Mr.Peng YAN,Prof.Guowen MENG,and Prof.Guanghui LI for their helps in the preparation of this manuscript.
文摘This article reviews the recent developments in the controlled growth of one-dimensional (1D) oxide nanomaterials, including ZnO, SnO2, In203, Ga203, SiOx, MgO, and Al203. The growth of 2D oxide nanomaterials was carried out in a simple chemical vapor transport and condensation system. This article will begin with a survey of nanotechnology and 1D nanomaterials achieved by many researchers, and then mainly discuss on the controlled growth of ID oxide nanomaterials with their morphologies, sizes, compositions, and microstructures controlled by altering experimental parameters, such as the temperature at the source material and the substrate, temperature gradient in the tube furnace, the total reaction time, the heating rate of the furnace, the gas flow rate, and the starting material. Their roles in the formation of various morphologies are analyzed and discussed. Finally, this review will be concluded with personal perspectives on the future research directions of this area.
基金The authors acknowledge the support from the National Major Project of Fundamental Research:Nanomaterials and Nanostructures(Grant No.2005CB623603)the National Natural Science Foundation of China(Grant Nos.10304018,10574131)Special Fund for President Scholarship,Chinese Academy of Sciences.
文摘One-dimensional (1D) nanomaterials and nanostructures have received much attention due to their potential interest for understanding fundamental physical concepts and for applications in constructing nanoscale electric and optoelectronic devices. Zinc sulfide (ZnS) is an important semiconductor compound of Ⅱ-Ⅵ group, and the synthesis of 1D ZnS nanomaterials and nanostructures has been of growing interest owing to their promising application in nanoscale optoelectronic devices. This paper reviews the recent progress on 1D ZnS nanomaterials and nanostructures, including nanowires, nanowire arrays, nanorods, nanobelts or nanoribbons, nanocables, and hierarchical nanostructures etc. This article begins with a survey of various methods that have been developed for generating 1D nanomaterials and nanostructures, and then mainly focuses on structures, synthesis, characterization, formation mechanisms and optical property tuning, and luminescence mechanisms of 1D ZnS nanomaterials and nanostructures. Finally, this review concludes with personal views towards future research on 1D ZnS nanomaterials and nanostructures.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11262017,11262012,and 11462020)the Natural Science Foundation of Inner Mongolia Autonomous Region,China(Grant No.2015MS0129)+1 种基金the Programme of Higher-level Talents of Inner Mongolia Normal University(Grant No.RCPY-2-2012-K-035)the Key Project of Inner Mongolia Normal University(Grant No.2014ZD03)
文摘Based on the fundamental equations of piezoelasticity of quasicrystal material,we investigated the interaction between a screw dislocation and a wedge-shaped crack in the piezoelectricity of one-dimensional hexagonal quasicrystals.Explicit analytical solutions are obtained for stress and electric displacement intensity factors of the crack,as well as the force on dislocation.The derivation is based on the conformal mapping method and the perturbation technique.The influences of the wedge angle and dislocation location on the image force are also discussed.The results obtained in this paper can be fully reduced to some special cases already available or deriving new ones.
基金Project supported by the National Key R&D Program of China (Grant No. 2017YFC1405605)the Innovation Youth Fund of the Ocean Telemetry Technology Innovation Center of the Ministry of Natural Resources, China (Grant No. 21k20190088)+1 种基金the Natural Science Foundation of Inner Mongolia, China (Grant No. 2018MS01005)the Graduate Students' Scientific Research Innovation Program of Inner Mongolia Normal University (Grant No. CXJJS19098).
文摘By constructing a new conformal mapping function, we study the surface effects on six edge nano-cracks emanating from a regular hexagonal nano-hole in one-dimensional (1D) hexagonal piezoelectric quasicrystals under anti-plane shear. Based on the Gurtin–Murdoch surface/interface model and complex potential theory, the exact solutions of phonon field, phason field and electric field are obtained. The analytical solutions of the stress intensity factor of the phonon field, the stress intensity factor of the phason field, the electric displacement intensity factor and the energy release rate are given. The interaction effects of the nano-cracks and nano-hole on the stress intensity factor of the phonon field, the stress intensity factor of the phason field and the electric displacement intensity factor are discussed in numerical examples. It can be seen that the surface effect leads to the coupling of phonon field, phason field and electric field. With the decrease of cavity size, the influence of surface effect is more obvious.
基金financial support Independent Innovation Foundation of Shandong University(IIFSDU-2009JQ011)
文摘One-dimensional Cd S@TiO_2 core-shell heterostructures were fabricated via the hydrolysis of tetrabutyl titanate(TBT) on preformed Cd S nanowires. The as-prepared products were characterized by X-ray diffraction, transmission electron microscopy, selected area electron diffraction and diffuse reflectance spectroscopy techniques. Results demonstrated that the hydrolysis of TBT had a great influence on the morphology of the coated TiO_2 shell, resulting in the formation of TiO_2 nanoparticles and nanolayer-modified Cd S@TiO_2 heterostructures. Degradation of methylene blue using Cd S@TiO_2 core-shell heterostructures as photocatalysts under visible light irradiation was investigated. Comparative photocatalytic tests showed that the TiO_2 nanoparticles-modified heterostructure exhibited a superior activity due to the passivity of photogenerated charge carriers.
基金supported by the National Natural Science Foundation of China (Grant No 10761005)the Inner Mongolia Natural Science Foundation of China (Grant No 200607010104)
文摘Using the complex variable function method and the technique of conformal mapping, the anti-plane shear problem of an elliptic hole with asymmetric colfinear cracks in a one-dimensional hexagonal quasi-crystal is solved, and the exact analytic solutions of the stress intensity factors (SIFs) for mode Ⅲ problem are obtained. Under the limiting conditions, the present results reduce to the Griffith crack and many new results obtained as well, such as the circular hole with asymmetric collinear cracks, the elliptic hole with a straight crack, the mode T crack, the cross crack and so on. As far as the phonon field is concerned, these results, which play an important role in many practical and theoretical applications, are shown to be in good agreement with the classical results.
文摘This paper presents an analytical solution of the one-dimensional consolidation in unsaturated soil with a finite thickness under vertical loading and confinements in the lateral directions. The boundary contains the top surface permeable to water and air and the bottom impermeable to water and air. The analytical solution is for Fredlund's one-dimensional consolidation equation in unsaturated soils. The transfer relationship between the state vectors at top surface and any depth is obtained by using the Laplace transform and Cayley-Hamilton mathematical methods to the governing equations of water and air, Darcy's law and Fick's law. Excess pore-air pressure, excess pore-water pressure and settlement in the Laplace-transformed domain are obtained by using the Laplace transform with the initial conditions and boundary conditions. By performing inverse Laplace transforms, the analytical solutions are obtained in the time domain. A typical example illustrates the consolidation characteristics of unsaturated soil from an- alytical results. Finally, comparisons between the analytical solutions and results of the finite difference method indicate that the analytical solution is correct.
基金the National Key R&D Program of China(No.2016YFC0700904)。
文摘(GO/TiO2)N(GO represents graphene oxide,and N represents the period number of alternate superposition of two dielectrics)onedimensional photonic crystal with different lattice constants was prepared via the sol–gel technique,and its transmission characteristics for photocatalysis were tested.The results show that the lattice constant,filling ratio,number of periodic layers,and incident angle had effects on the band gap.When the lattice constant,filling ratio,number of periodic layers,and incident angle were set to 125 nm,0.45,21,and 0°,respectively,a gap width of 53 nm appeared at the central wavelength(322 nm).The absorption peak of the photocatalyst at 357 nm overlapped the blue edge of the photonic band gap.A slow photon effect region above 96%reflectivity appeared.The degradation rate of tetracycline in(GO/TiO2)N photonic crystal was enhanced to 64%within 60 min.Meanwhile,the degradation efficiency of(GO/TiO2)N one-dimensional photonic crystal was effectively improved compared with those of the GO/TiO2 composite film and GO/TiO2 powder.