Rock discontinuities control rock mechanical behaviors and significantly influence the stability of rock masses.However,existing discontinuity mapping algorithms are susceptible to noise,and the calculation results ca...Rock discontinuities control rock mechanical behaviors and significantly influence the stability of rock masses.However,existing discontinuity mapping algorithms are susceptible to noise,and the calculation results cannot be fed back to users timely.To address this issue,we proposed a human-machine interaction(HMI)method for discontinuity mapping.Users can help the algorithm identify the noise and make real-time result judgments and parameter adjustments.For this,a regular cube was selected to illustrate the workflows:(1)point cloud was acquired using remote sensing;(2)the HMI method was employed to select reference points and angle thresholds to detect group discontinuity;(3)individual discontinuities were extracted from the group discontinuity using a density-based cluster algorithm;and(4)the orientation of each discontinuity was measured based on a plane fitting algorithm.The method was applied to a well-studied highway road cut and a complex natural slope.The consistency of the computational results with field measurements demonstrates its good accuracy,and the average error in the dip direction and dip angle for both cases was less than 3.Finally,the computational time of the proposed method was compared with two other popular algorithms,and the reduction in computational time by tens of times proves its high computational efficiency.This method provides geologists and geological engineers with a new idea to map rapidly and accurately rock structures under large amounts of noises or unclear features.展开更多
Luminescent metal-organic frameworks(MOFs)have garnered significant attention due to their structural tunability and potential applications in solid-state lighting,bioimaging,sensing,anticounterfeiting,and other field...Luminescent metal-organic frameworks(MOFs)have garnered significant attention due to their structural tunability and potential applications in solid-state lighting,bioimaging,sensing,anticounterfeiting,and other fields.Nevertheless,due to the tendency of1,4-benzenedicarboxylic acid(BDC)to rotate within the framework,MOFs composed of it exhibit significant non-radiative energy dissipation and thus impair the emissive properties.In this study,efficient luminescence of MIL-140A nanocrystals(NCs)with BDC rotors as ligands is achieved by pressure treatment strategy.Pressure treatment effectively modulates the pore structure of the framework,enhancing the interactions between the N,N-dimethylformamide vip molecules and the BDC ligands.The enhanced host-vip interaction contributes to the structural rigidity of the MOF,thereby suppressing the rotation-induced excited-state energy loss.As a result,the pressure-treated MIL-140A NCs displayed bright blue-light emission,with the photoluminescence quantum yield increasing from an initial 6.8%to 69.2%.This study developed an effective strategy to improve the luminescence performance of rotor ligand MOFs,offers a new avenue for the rational design and synthesis of MOFs with superior luminescent properties.展开更多
Three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） is used to describe the chemical structures of polychlorinated naphthalenes（PCNs）.After variable screening by stepwise multiple regressio...Three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） is used to describe the chemical structures of polychlorinated naphthalenes（PCNs）.After variable screening by stepwise multiple regression（SMR） technique,the liner relationships between gas-chromatographic relative retention time（RRT）,298 K supercooled liquid pressures（logPL）,n-octanol/air partition coefficient（logKOA）,n-octanol/water partition coefficient（logKOW）,aqueous solubilities（logSW）,relative in vitro potency values（-logEROD） of PCNs and 3D-HoVAIF descriptors have been established by partial least-square（PLS） regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property（activity） relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models.展开更多
The interaction of arbitrarily distributed penny-shaped cracks in three-dimensional solids is analyzed in this paper. Using oblate spheroidal coordinates and displacement functions, an analytic method is devel- oped i...The interaction of arbitrarily distributed penny-shaped cracks in three-dimensional solids is analyzed in this paper. Using oblate spheroidal coordinates and displacement functions, an analytic method is devel- oped in which the opening and the sliding displacements on each crack surface are taken as the basic unknown functions. The basic unknown functions can be expanded in series of Legendre polynomials with unknown coefficients. Based on superposition technique, a set of governing equations for the unknown coefficients are formulated from the traction free conditions on each crack surface. The boundary collocation procedure and the average method for crack-surface tractions are used for solving the governing equations. The solution can be obtained for quite closely located cracks. Numerical examples are given for several crack problems. By comparing the present results with other existing results, one can conclude that the present method provides a direct and efficient approach to deal with three-dimensional solids containing multiple cracks.展开更多
The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident...The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.展开更多
The closely coupled approach combined with the finite volume method （FVM） solver and the finite element method （FEM） solver is used to investigate the fluid-structure interaction （FSI） of a three-dimensional can...The closely coupled approach combined with the finite volume method （FVM） solver and the finite element method （FEM） solver is used to investigate the fluid-structure interaction （FSI） of a three-dimensional cantilevered hydrofoil in the water tunnel. The FVM solver and the coupled approach are verified and validated by compar- ing the numerical predictions with the experimental measurements, and good agreement is obtained concerning both the lift on the foil and the tip displacement. In the noncav- itating flow, the result indicates that the growth of the initial incidence angle and the Reynolds number improves the deformation of the foil, and the lift on the foil is increased by the twist deformation. The normalized twist angle and displacement along the span of the hydrofoil for different incidence angles and Reynolds numbers are almost uniform. For the cavitation flow, it is shown that the small amplitude vibration of the foil has limited influence on the developing process of the partial cavity, and the quasi two-dimensional cavity shedding does not change the deformation mode of the hydrofoil. However, the frequency spectrum of the lift on the foil contains the frequency which is associated with the first bend frequency of the hydrofoil.展开更多
The nonlinear finite element（FE） analysis has been widely used in the design and analysis of structural or geotechnical systems.The response sensitivities（or gradients） to the model parameters are of significant i...The nonlinear finite element（FE） analysis has been widely used in the design and analysis of structural or geotechnical systems.The response sensitivities（or gradients） to the model parameters are of significant importance in these realistic engineering problems.However the sensitivity calculation has lagged behind,leaving a gap between advanced FE response analysis and other research hotspots using the response gradient.The response sensitivity analysis is crucial for any gradient-based algorithms,such as reliability analysis,system identification and structural optimization.Among various sensitivity analysis methods,the direct differential method（DDM） has advantages of computing efficiency and accuracy,providing an ideal tool for the response gradient calculation.This paper extended the DDM framework to realistic complicated soil-foundation-structure interaction（SFSI） models by developing the response gradients for various constraints,element and materials involved.The enhanced framework is applied to three-dimensional SFSI system prototypes for a pilesupported bridge pier and a pile-supported reinforced concrete building frame structure,subjected to earthquake loading conditions.The DDM results are verified by forward finite difference method（FFD）.The relative importance（RI） of the various material parameters on the responses of SFSI system are investigated based on the DDM response sensitivity results.The FFD converges asymptotically toward the DDM results,demonstrating the advantages of DDM（e.g.,accurate,efficient,insensitive to numerical noise）.Furthermore,the RI and effects of the model parameters of structure,foundation and soil materials on the responses of SFSI systems are investigated by taking advantage of the sensitivity analysis results.The extension of DDM to SFSI systems greatly broaden the application areas of the d gradient-based algorithms,e.g.FE model updating and nonlinear system identification of complicated SFSI systems.展开更多
A new complex, [Ni2（L）4（H2O）8]（1, L1 = 4-（1H-imidazol-4-yl）benzoic acid）, has been hydrothermally prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and PXRD. C...A new complex, [Ni2（L）4（H2O）8]（1, L1 = 4-（1H-imidazol-4-yl）benzoic acid）, has been hydrothermally prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and PXRD. Complex 1 crystallizes in monoclinic, space group P21/c with α = 22.281（2）, b = 7.3959（7）, c = 24.978（3） ？, β = 90.876（10）, V = 4115.6（7） ？3, Z = 8, C20H22N4O8Ni, Mr = 505.13, Dc = 1.630 g/cm3, μ = 1.001 mm-1, S = 1.080, F（000） = 2096, the final R = 0.452 and wR = 0.1152 for 9380 observed reflections （I 〉 2σ（I））. The result of X-ray diffraction analysis revealed three different kinds of Ni（II） centre mononuclear molecules in the asymmetric unit. The independent mononuclear units are bridged to form a three-dimensional supramolecular polymer by extensive hydrogen bonds and C–H… non-covalent bonding interactions.展开更多
We theoretically investigate the extended Bose-Hubbard model using a three-dimensional cubic lattice.In the framework of the dynamical Gutzwiller mean-field theory,we identify a checkerboard supersolid phase.By consid...We theoretically investigate the extended Bose-Hubbard model using a three-dimensional cubic lattice.In the framework of the dynamical Gutzwiller mean-field theory,we identify a checkerboard supersolid phase.By considering the repulsive interactions between next-nearest-neighbor lattice sites,we further discover an exotic type of supersolid state,whose site occupancies show a stereoscopically arrayed and staggered distribution rather than checkerboard ordering.Intriguingly,if the physical observations of two neighboring layers were superimposed,they would give rise to a checkerboard configuration.This novel structure is convincingly induced by the simultaneous existence of nearest-neighbor and nextnearest-neighbor interactions.We also identify arrayed stripes in the ground state,as well as arrayed holes in the pattern of occupancies.展开更多
Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,...Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.展开更多
The interaction of two underwater explosion bubbles was mathematically analyzed in this paper. Based on the assumption of potential flow, high-order curved elements were used to discretize the boundary integral equati...The interaction of two underwater explosion bubbles was mathematically analyzed in this paper. Based on the assumption of potential flow, high-order curved elements were used to discretize the boundary integral equation and solve it. Assuming that gas inside the bubble follows the isentropic rule, the Euler-Lagrange method was used to trace the evolution of the bubble, and when calculating the singular integral, the singularity of the double-layer singular integral was eliminated by reconstructing a principal-value integral of double-layer potential so that a more precise result could be obtained. Elastic mesh technique (EMT) was also used when tracing the evolution of the bubble interface, and numerical smoothing wasn't needed. A comparison of calculations using this three-dimensional model with results of the Reyleigh-Plesset bubble model shows that the three-dimensional model and calculation method in this paper is practical. This three-dimensional model was applied to simulate the interaction of two bubbles under the action of gravity, and the dynamic characteristics of two bubbles near the surface was also analyzed. Bubbles influenced by surface effects and gravity present severe non-linearity. This paper provides a reference for research into the dynamics of multi-bubbles.展开更多
The objective of this study was to develop, as well as validate the strongly coupled method (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the vertical axis tidal turbine (...The objective of this study was to develop, as well as validate the strongly coupled method (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the vertical axis tidal turbine (VATT) rotor, subjected to spatially varying inflow. Moreover, this study examined strategies on improving techniques used for mesh deformation that account for large displacement or deformation calculations. The blade's deformation for each new time step is considered in transient two-way FSI analysis, to make the design more reliable. Usually this is not considered in routine one-way FSI simulations. A rotor with four blades and 4-m diameter was modeled and numerically analyzed. We observed that two-way FSI, utilizing the strongly coupled method, was impossible for a complex model; and thereby using ANSYS-CFX and ANSYS-MECHANICAL in work bench, as given in ANSYS-WORKBENCH, helped case examples 22 and 23, by giving an error when the solution was run. To make the method possible and reduce the computational power, a novel technique was used to transfer the file in ANSYS-APDL to obtain the solution and results. Consequently, the results indicating a two-way transient FSI analysis is a time- and resource-consuming job, but with our proposed technique we can reduce the computational time. The ANSYS STRUCTURAL results also uncover that stresses and deformations have higher values for two-way FSI as compared to one-way FSI. Similarly, fluid flow CFX results for two-way FSI are closer to experimental results as compared to one-way simulation results. Additionally, this study shows that, using the proposed method we can perform coupled simulation with simple multi-node PCs (core i5).展开更多
Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventio...Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventional models, we can simulate the propagating pattern of action potential along the axonal membrane based on Ohm＇s law and Kirchhoff＇s law. However, we could not fully explain the different conductive patterns in unmyelinated and myelinated nerves with these theories. Also, whether we can really suppose closed electrical circuits in the actual site of the nerves or not has not been fully discussed yet. In this report, a recently introduced new theoretical model of nerve conduction based on electrostatic molecular interactions within the axoplasm will be reviewed. With this new approach, we can explain the different conductive patterns in unmyelinated and myelinated nerves. This new mathematical conductive model based on electrostatic compressional wave in the intracellular fluid may also be able to explain the signal integration in the neuronal cell body and the back-propagation mechanism from the axons to the dendrites. With this new mathematical nerve conduction model based on electrostatic molecular interactions within the intracellular fluid, we may be able to achieve an integrated explanation for the physiological phenomena taking place in the nervous system.展开更多
Study on the quantitative structure-activity relationship （QSAR） of 26 compounds, N-[5-（2-furanyl）-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-（2-furanyl）-2-methyl-3H-thieno[2...Study on the quantitative structure-activity relationship （QSAR） of 26 compounds, N-[5-（2-furanyl）-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-（2-furanyl）-2-methyl-3H-thieno[2,3-d]pyrimidin-4-ones, with three-dimensional holographic vector of atomic interaction field （3D-HoVAIF） was carried out. SMR-PLS QSAR models have been created and good correlation coefficients and cross-validated correlation coefficients were obtained. The result shows that the models have good prediction capability and favorable stability and the 3D-HoVAIF is applicable to the molecular structural characterization and biological activity prediction.展开更多
Although scientific and policy bodies have stated that nanomaterials are not intrinsically toxic, there is interest in evaluating if and how many engineered nanomaterials may do harm to the health of mankind and the e...Although scientific and policy bodies have stated that nanomaterials are not intrinsically toxic, there is interest in evaluating if and how many engineered nanomaterials may do harm to the health of mankind and the ecological environment. The interaction between nano-TiO2 and bovine serum albumin (BSA) was studied by using TDFS and UV methods in this research.展开更多
Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall intensity.Howev...Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall intensity.However,the hydrological response of vegetated slopes,especially three-dimensional(3D)slopes covered with shrubs,under different rainfall patterns remains unclear and requires further investigation.To address this issue,this study adopts a novel 3D numerical model for simulating hydraulic interactions between the root system of the shrub and the surrounding soil.Three series of numerical parametric studies are conducted to investigate the influences of slope inclination,rainfall pattern and rainfall duration.Four rainfall patterns(advanced,bimodal,delayed,and uniform)and two rainfall durations(4-h intense and 168-h mild rainfall)are considered to study the hydrological response of the slope.The computed results show that 17%higher transpiration-induced suction is found for a steeper slope,which remains even after a short,intense rainfall with a 100-year return period.The extreme rainfalls with advanced(PA),bimodal(PB)and uniform(PU)rainfall patterns need to be considered for the short rainfall duration(4 h),while the delayed(PD)and uniform(PU)rainfall patterns are highly recommended for long rainfall durations(168 h).The presence of plants can improve slope stability markedly under extreme rainfall with a short duration(4 h).For the long duration(168 h),the benefit of the plant in preserving pore-water pressure(PWP)and slope stability may not be sufficient.展开更多
The soil-pile-bridge interaction of super-large pile groups is a very complex issue for the design of deep pile group foundations. In this paper, the load distribution on the pile top of a super large bridge foundatio...The soil-pile-bridge interaction of super-large pile groups is a very complex issue for the design of deep pile group foundations. In this paper, the load distribution on the pile top of a super large bridge foundation and its influential factors are analyzed comprehensively using a three-dimensional elasto-plastic finite element method. The adopted model and its input parameters are firstly verified by comparing the numerical results with the measured data of static loading tests of a single pile. Numerical analysis is then performed to investigate the load distribution and the load-settlement characteristics of super-large pile groups, and the models are verified using centrifuge laboratory model testing data. The mechanism of the interaction between pile groups and soil under different conditions is explored.展开更多
In this paper, we report our study on a numerical fluid-structure interaction problem originally presented by Mok et al.(2001) in two dimensions and later studied in three dimensions by Valdés Vazquez(2007), Lomb...In this paper, we report our study on a numerical fluid-structure interaction problem originally presented by Mok et al.(2001) in two dimensions and later studied in three dimensions by Valdés Vazquez(2007), Lombardi(2012), and Trimarchi(2012). We focus on a 3D test case in which we evaluated the sensitivity of several input parameters on the fluid and structural results. In particular, this analysis provides a starting point from which we can look deeper into specific aspects of these simulations and analyze more realistic cases, e.g., in sails design. In this study, using the commercial software ADINATM, we addressed a well-known unsteadiness problem comprising a square box representing the fluid domain with a flexible bottom modeled with structural shell elements. We compared data from previously published work whose authors used the same numerical approach, i.e., a partitioned approach coupling a finite volume solver(for the fluid domain) and a finite element solver(for the solid domain). Specifically, we established several benchmarks and made comparisons with respect to fluid and solid meshes, structural element types, and structural damping, as well as solution algorithms. Moreover, we compared our method with a monolithic finite element solution method. Our comparisons of new and old results provide an outline of best practices for such simulations.展开更多
A novel co-ordination polymer based on IB metal thiocyanates, [Ag2（NCS）2（4,4＇-bipy）]. （1）（4,4＇-bipy = 4,4＇-bispyridine）, has been synthesized by the pre-assembly method and characterized by X-ray crystallog...A novel co-ordination polymer based on IB metal thiocyanates, [Ag2（NCS）2（4,4＇-bipy）]. （1）（4,4＇-bipy = 4,4＇-bispyridine）, has been synthesized by the pre-assembly method and characterized by X-ray crystallography. The complex exists as a three- dimensional network consisting of （AgSCN）. undulating layers linked by 4,4＇-bipy bridges.展开更多
We propose a more efficient and reliable scheme for transferring quantum states between distant atoms than previous schemes based on resonant atom-cavity interaction.In addition,our system can also be used to implemen...We propose a more efficient and reliable scheme for transferring quantum states between distant atoms than previous schemes based on resonant atom-cavity interaction.In addition,our system can also be used to implement a controlled phase gate with high fidelity.展开更多
基金supported by the National Key R&D Program of China(No.2023YFC3081200)the National Natural Science Foundation of China(No.42077264)the Scientific Research Project of PowerChina Huadong Engineering Corporation Limited(HDEC-2022-0301).
文摘Rock discontinuities control rock mechanical behaviors and significantly influence the stability of rock masses.However,existing discontinuity mapping algorithms are susceptible to noise,and the calculation results cannot be fed back to users timely.To address this issue,we proposed a human-machine interaction(HMI)method for discontinuity mapping.Users can help the algorithm identify the noise and make real-time result judgments and parameter adjustments.For this,a regular cube was selected to illustrate the workflows:(1)point cloud was acquired using remote sensing;(2)the HMI method was employed to select reference points and angle thresholds to detect group discontinuity;(3)individual discontinuities were extracted from the group discontinuity using a density-based cluster algorithm;and(4)the orientation of each discontinuity was measured based on a plane fitting algorithm.The method was applied to a well-studied highway road cut and a complex natural slope.The consistency of the computational results with field measurements demonstrates its good accuracy,and the average error in the dip direction and dip angle for both cases was less than 3.Finally,the computational time of the proposed method was compared with two other popular algorithms,and the reduction in computational time by tens of times proves its high computational efficiency.This method provides geologists and geological engineers with a new idea to map rapidly and accurately rock structures under large amounts of noises or unclear features.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406200)the National Natural Science Foundation of China(No.12274177 and 12304261)the China Postdoctoral Science Foundation(No.2024M751076)。
文摘Luminescent metal-organic frameworks(MOFs)have garnered significant attention due to their structural tunability and potential applications in solid-state lighting,bioimaging,sensing,anticounterfeiting,and other fields.Nevertheless,due to the tendency of1,4-benzenedicarboxylic acid(BDC)to rotate within the framework,MOFs composed of it exhibit significant non-radiative energy dissipation and thus impair the emissive properties.In this study,efficient luminescence of MIL-140A nanocrystals(NCs)with BDC rotors as ligands is achieved by pressure treatment strategy.Pressure treatment effectively modulates the pore structure of the framework,enhancing the interactions between the N,N-dimethylformamide vip molecules and the BDC ligands.The enhanced host-vip interaction contributes to the structural rigidity of the MOF,thereby suppressing the rotation-induced excited-state energy loss.As a result,the pressure-treated MIL-140A NCs displayed bright blue-light emission,with the photoluminescence quantum yield increasing from an initial 6.8%to 69.2%.This study developed an effective strategy to improve the luminescence performance of rotor ligand MOFs,offers a new avenue for the rational design and synthesis of MOFs with superior luminescent properties.
基金supported by the Ministry of Science and Technology of China (2010DFA32680)the National Natural Science Foundation of China (21005062)the Fundamental Research Funds for the Central Universities (CDJRC10220010)
文摘Three-dimensional holographic vector of atomic interaction field（3D-HoVAIF） is used to describe the chemical structures of polychlorinated naphthalenes（PCNs）.After variable screening by stepwise multiple regression（SMR） technique,the liner relationships between gas-chromatographic relative retention time（RRT）,298 K supercooled liquid pressures（logPL）,n-octanol/air partition coefficient（logKOA）,n-octanol/water partition coefficient（logKOW）,aqueous solubilities（logSW）,relative in vitro potency values（-logEROD） of PCNs and 3D-HoVAIF descriptors have been established by partial least-square（PLS） regression.The result shows that the 3D-HoVAIF descriptors can be well used to express the quantitative structure-property（activity） relationships of PCNs.Predictive capability of the models has also been demonstrated by leave-one-out cross-validation.Moreover,the predicted values have been presented for those PCNs which are lack of experimentally physico-chemical properties and biological activity by the optimum models.
文摘The interaction of arbitrarily distributed penny-shaped cracks in three-dimensional solids is analyzed in this paper. Using oblate spheroidal coordinates and displacement functions, an analytic method is devel- oped in which the opening and the sliding displacements on each crack surface are taken as the basic unknown functions. The basic unknown functions can be expanded in series of Legendre polynomials with unknown coefficients. Based on superposition technique, a set of governing equations for the unknown coefficients are formulated from the traction free conditions on each crack surface. The boundary collocation procedure and the average method for crack-surface tractions are used for solving the governing equations. The solution can be obtained for quite closely located cracks. Numerical examples are given for several crack problems. By comparing the present results with other existing results, one can conclude that the present method provides a direct and efficient approach to deal with three-dimensional solids containing multiple cracks.
基金National Natural Science Foundation of China under Grant No.51478247National Key Research and Development Program of China under Grant No.2016YFC1402800
文摘The method of inputting the seismic wave determines the accuracy of the simulation of soil-structure dynamic interaction. The wave method is a commonly used approach for seismic wave input, which converts the incident wave into equivalent loads on the cutoff boundaries. The wave method has high precision, but the implementation is complicated, especially for three-dimensional models. By deducing another form of equivalent input seismic loads in the fi nite element model, a new seismic wave input method is proposed. In the new method, by imposing the displacements of the free wave fi eld on the nodes of the substructure composed of elements that contain artifi cial boundaries, the equivalent input seismic loads are obtained through dynamic analysis of the substructure. Subsequently, the equivalent input seismic loads are imposed on the artifi cial boundary nodes to complete the seismic wave input and perform seismic analysis of the soil-structure dynamic interaction model. Compared with the wave method, the new method is simplifi ed by avoiding the complex processes of calculating the equivalent input seismic loads. The validity of the new method is verifi ed by the dynamic analysis numerical examples of the homogeneous and layered half space under vertical and oblique incident seismic waves.
基金Project supported by the National Natural Science Foundation of China(No.10832007)the Shanghai Leading Academic Discipline Project(No.B206)
文摘The closely coupled approach combined with the finite volume method （FVM） solver and the finite element method （FEM） solver is used to investigate the fluid-structure interaction （FSI） of a three-dimensional cantilevered hydrofoil in the water tunnel. The FVM solver and the coupled approach are verified and validated by compar- ing the numerical predictions with the experimental measurements, and good agreement is obtained concerning both the lift on the foil and the tip displacement. In the noncav- itating flow, the result indicates that the growth of the initial incidence angle and the Reynolds number improves the deformation of the foil, and the lift on the foil is increased by the twist deformation. The normalized twist angle and displacement along the span of the hydrofoil for different incidence angles and Reynolds numbers are almost uniform. For the cavitation flow, it is shown that the small amplitude vibration of the foil has limited influence on the developing process of the partial cavity, and the quasi two-dimensional cavity shedding does not change the deformation mode of the hydrofoil. However, the frequency spectrum of the lift on the foil contains the frequency which is associated with the first bend frequency of the hydrofoil.
基金National Key Research and Development Program of China under Grant No.2016YFC0701106Natural Sciences and Engineering Research Council of Canada via Discovery under Grant No.NSERC RGPIN-2017-05556 Li
文摘The nonlinear finite element（FE） analysis has been widely used in the design and analysis of structural or geotechnical systems.The response sensitivities（or gradients） to the model parameters are of significant importance in these realistic engineering problems.However the sensitivity calculation has lagged behind,leaving a gap between advanced FE response analysis and other research hotspots using the response gradient.The response sensitivity analysis is crucial for any gradient-based algorithms,such as reliability analysis,system identification and structural optimization.Among various sensitivity analysis methods,the direct differential method（DDM） has advantages of computing efficiency and accuracy,providing an ideal tool for the response gradient calculation.This paper extended the DDM framework to realistic complicated soil-foundation-structure interaction（SFSI） models by developing the response gradients for various constraints,element and materials involved.The enhanced framework is applied to three-dimensional SFSI system prototypes for a pilesupported bridge pier and a pile-supported reinforced concrete building frame structure,subjected to earthquake loading conditions.The DDM results are verified by forward finite difference method（FFD）.The relative importance（RI） of the various material parameters on the responses of SFSI system are investigated based on the DDM response sensitivity results.The FFD converges asymptotically toward the DDM results,demonstrating the advantages of DDM（e.g.,accurate,efficient,insensitive to numerical noise）.Furthermore,the RI and effects of the model parameters of structure,foundation and soil materials on the responses of SFSI systems are investigated by taking advantage of the sensitivity analysis results.The extension of DDM to SFSI systems greatly broaden the application areas of the d gradient-based algorithms,e.g.FE model updating and nonlinear system identification of complicated SFSI systems.
基金supported by the National Natural Science Foundation of China(Nos.21171040 and 21302019)
文摘A new complex, [Ni2（L）4（H2O）8]（1, L1 = 4-（1H-imidazol-4-yl）benzoic acid）, has been hydrothermally prepared and characterized by single-crystal X-ray diffraction, IR spectroscopy, elemental analysis and PXRD. Complex 1 crystallizes in monoclinic, space group P21/c with α = 22.281（2）, b = 7.3959（7）, c = 24.978（3） ？, β = 90.876（10）, V = 4115.6（7） ？3, Z = 8, C20H22N4O8Ni, Mr = 505.13, Dc = 1.630 g/cm3, μ = 1.001 mm-1, S = 1.080, F（000） = 2096, the final R = 0.452 and wR = 0.1152 for 9380 observed reflections （I 〉 2σ（I））. The result of X-ray diffraction analysis revealed three different kinds of Ni（II） centre mononuclear molecules in the asymmetric unit. The independent mononuclear units are bridged to form a three-dimensional supramolecular polymer by extensive hydrogen bonds and C–H… non-covalent bonding interactions.
基金supported by the Hainan Provincial Natural Science Foundation of China(Grant No.525QN342)the Scientific Research Foundation of Hainan Tropical Ocean University(Grant No.RHDRC202301).
文摘We theoretically investigate the extended Bose-Hubbard model using a three-dimensional cubic lattice.In the framework of the dynamical Gutzwiller mean-field theory,we identify a checkerboard supersolid phase.By considering the repulsive interactions between next-nearest-neighbor lattice sites,we further discover an exotic type of supersolid state,whose site occupancies show a stereoscopically arrayed and staggered distribution rather than checkerboard ordering.Intriguingly,if the physical observations of two neighboring layers were superimposed,they would give rise to a checkerboard configuration.This novel structure is convincingly induced by the simultaneous existence of nearest-neighbor and nextnearest-neighbor interactions.We also identify arrayed stripes in the ground state,as well as arrayed holes in the pattern of occupancies.
基金This research was jointly funded by the Second Tibetan Plateau Scientific Expedition and Research Program(Grant Nos.2019QZKK0103 and 2019QZKK0105)the National Natural Science Foundation of China(Grant Nos.91837208 and 42075085).
文摘Changes in the water cycle on the Tibetan Plateau(TP)have a significant impact on local agricultural production and livelihoods and its downstream regions.Against the background of widely reported warming and wetting,the hydrological cycle has accelerated and the likelihood of extreme weather events and natural disasters occurring(i.e.,snowstorms,floods,landslides,mudslides,and ice avalanches)has also intensified,especially in the highelevation mountainous regions.Thus,an accurate estimation of the intensity and variation of each component of the water cycle is an urgent scientific question for the assessment of plateau environmental changes.Following the transformation and movement of water between the atmosphere,biosphere and hydrosphere,the authors highlight the urgent need to strengthen the three-dimensional comprehensive observation system(including the eddy covariance system;planetary boundary layer tower;profile measurements of temperature,humidity,and wind by microwave radiometers,wind profiler,and radiosonde system;and cloud and precipitation radars)in the TP region and propose a practical implementation plan.The construction of such a three-dimensional observation system is expected to promote the study of environmental changes and natural hazards prevention.
文摘The interaction of two underwater explosion bubbles was mathematically analyzed in this paper. Based on the assumption of potential flow, high-order curved elements were used to discretize the boundary integral equation and solve it. Assuming that gas inside the bubble follows the isentropic rule, the Euler-Lagrange method was used to trace the evolution of the bubble, and when calculating the singular integral, the singularity of the double-layer singular integral was eliminated by reconstructing a principal-value integral of double-layer potential so that a more precise result could be obtained. Elastic mesh technique (EMT) was also used when tracing the evolution of the bubble interface, and numerical smoothing wasn't needed. A comparison of calculations using this three-dimensional model with results of the Reyleigh-Plesset bubble model shows that the three-dimensional model and calculation method in this paper is practical. This three-dimensional model was applied to simulate the interaction of two bubbles under the action of gravity, and the dynamic characteristics of two bubbles near the surface was also analyzed. Bubbles influenced by surface effects and gravity present severe non-linearity. This paper provides a reference for research into the dynamics of multi-bubbles.
基金supported by the National Natural Science Foundation of China (Nos. 51209060 and 51106034)the ‘111’ Project Foundation from Ministry of Education and State Administration of Foreign Experts Affairs (No. B07019), Chinathe National Special Foundation for Ocean Energy (No. GHME2010CY01)
文摘The objective of this study was to develop, as well as validate the strongly coupled method (two-way fluid structural interaction (FSI)) used to simulate the transient FSI response of the vertical axis tidal turbine (VATT) rotor, subjected to spatially varying inflow. Moreover, this study examined strategies on improving techniques used for mesh deformation that account for large displacement or deformation calculations. The blade's deformation for each new time step is considered in transient two-way FSI analysis, to make the design more reliable. Usually this is not considered in routine one-way FSI simulations. A rotor with four blades and 4-m diameter was modeled and numerically analyzed. We observed that two-way FSI, utilizing the strongly coupled method, was impossible for a complex model; and thereby using ANSYS-CFX and ANSYS-MECHANICAL in work bench, as given in ANSYS-WORKBENCH, helped case examples 22 and 23, by giving an error when the solution was run. To make the method possible and reduce the computational power, a novel technique was used to transfer the file in ANSYS-APDL to obtain the solution and results. Consequently, the results indicating a two-way transient FSI analysis is a time- and resource-consuming job, but with our proposed technique we can reduce the computational time. The ANSYS STRUCTURAL results also uncover that stresses and deformations have higher values for two-way FSI as compared to one-way FSI. Similarly, fluid flow CFX results for two-way FSI are closer to experimental results as compared to one-way simulation results. Additionally, this study shows that, using the proposed method we can perform coupled simulation with simple multi-node PCs (core i5).
文摘Until now, nerve conduction has been described on the basis of equivalent circuit model and cable theory, both of which supposed closed electric circuits spreading inside and outside the axoplasm. With these conventional models, we can simulate the propagating pattern of action potential along the axonal membrane based on Ohm＇s law and Kirchhoff＇s law. However, we could not fully explain the different conductive patterns in unmyelinated and myelinated nerves with these theories. Also, whether we can really suppose closed electrical circuits in the actual site of the nerves or not has not been fully discussed yet. In this report, a recently introduced new theoretical model of nerve conduction based on electrostatic molecular interactions within the axoplasm will be reviewed. With this new approach, we can explain the different conductive patterns in unmyelinated and myelinated nerves. This new mathematical conductive model based on electrostatic compressional wave in the intracellular fluid may also be able to explain the signal integration in the neuronal cell body and the back-propagation mechanism from the axons to the dendrites. With this new mathematical nerve conduction model based on electrostatic molecular interactions within the intracellular fluid, we may be able to achieve an integrated explanation for the physiological phenomena taking place in the nervous system.
基金Supported by the Fund of National High Technology Research and Development Program (863 Program, No. 2006AA02Z312)
文摘Study on the quantitative structure-activity relationship （QSAR） of 26 compounds, N-[5-（2-furanyl）-2-methyl-4-oxo-4H-thieno[2,3-d]pyrimidin-3-yl]-carboxamide and 3-substituted- 5-（2-furanyl）-2-methyl-3H-thieno[2,3-d]pyrimidin-4-ones, with three-dimensional holographic vector of atomic interaction field （3D-HoVAIF） was carried out. SMR-PLS QSAR models have been created and good correlation coefficients and cross-validated correlation coefficients were obtained. The result shows that the models have good prediction capability and favorable stability and the 3D-HoVAIF is applicable to the molecular structural characterization and biological activity prediction.
基金Suppoted by National Nature Science Foundation of China (Grant Nos. 41130746, 41272371)the Doctor Foundation of SWUST of China (Grant No. 11zx7139)
文摘Although scientific and policy bodies have stated that nanomaterials are not intrinsically toxic, there is interest in evaluating if and how many engineered nanomaterials may do harm to the health of mankind and the ecological environment. The interaction between nano-TiO2 and bovine serum albumin (BSA) was studied by using TDFS and UV methods in this research.
文摘Understanding the pore water pressure distribution in unsaturated soil is crucial in predicting shallow landslides triggered by rainfall,mainly when dealing with different temporal patterns of rainfall intensity.However,the hydrological response of vegetated slopes,especially three-dimensional(3D)slopes covered with shrubs,under different rainfall patterns remains unclear and requires further investigation.To address this issue,this study adopts a novel 3D numerical model for simulating hydraulic interactions between the root system of the shrub and the surrounding soil.Three series of numerical parametric studies are conducted to investigate the influences of slope inclination,rainfall pattern and rainfall duration.Four rainfall patterns(advanced,bimodal,delayed,and uniform)and two rainfall durations(4-h intense and 168-h mild rainfall)are considered to study the hydrological response of the slope.The computed results show that 17%higher transpiration-induced suction is found for a steeper slope,which remains even after a short,intense rainfall with a 100-year return period.The extreme rainfalls with advanced(PA),bimodal(PB)and uniform(PU)rainfall patterns need to be considered for the short rainfall duration(4 h),while the delayed(PD)and uniform(PU)rainfall patterns are highly recommended for long rainfall durations(168 h).The presence of plants can improve slope stability markedly under extreme rainfall with a short duration(4 h).For the long duration(168 h),the benefit of the plant in preserving pore-water pressure(PWP)and slope stability may not be sufficient.
基金Funded by the National Natural Science Foundation of China(No.41372276)
文摘The soil-pile-bridge interaction of super-large pile groups is a very complex issue for the design of deep pile group foundations. In this paper, the load distribution on the pile top of a super large bridge foundation and its influential factors are analyzed comprehensively using a three-dimensional elasto-plastic finite element method. The adopted model and its input parameters are firstly verified by comparing the numerical results with the measured data of static loading tests of a single pile. Numerical analysis is then performed to investigate the load distribution and the load-settlement characteristics of super-large pile groups, and the models are verified using centrifuge laboratory model testing data. The mechanism of the interaction between pile groups and soil under different conditions is explored.
文摘In this paper, we report our study on a numerical fluid-structure interaction problem originally presented by Mok et al.(2001) in two dimensions and later studied in three dimensions by Valdés Vazquez(2007), Lombardi(2012), and Trimarchi(2012). We focus on a 3D test case in which we evaluated the sensitivity of several input parameters on the fluid and structural results. In particular, this analysis provides a starting point from which we can look deeper into specific aspects of these simulations and analyze more realistic cases, e.g., in sails design. In this study, using the commercial software ADINATM, we addressed a well-known unsteadiness problem comprising a square box representing the fluid domain with a flexible bottom modeled with structural shell elements. We compared data from previously published work whose authors used the same numerical approach, i.e., a partitioned approach coupling a finite volume solver(for the fluid domain) and a finite element solver(for the solid domain). Specifically, we established several benchmarks and made comparisons with respect to fluid and solid meshes, structural element types, and structural damping, as well as solution algorithms. Moreover, we compared our method with a monolithic finite element solution method. Our comparisons of new and old results provide an outline of best practices for such simulations.
基金the Science Foundation for Distinguished Young Scholars of Henan Province(No.0612002800)the NSFC(No.20671083).
文摘A novel co-ordination polymer based on IB metal thiocyanates, [Ag2（NCS）2（4,4＇-bipy）]. （1）（4,4＇-bipy = 4,4＇-bispyridine）, has been synthesized by the pre-assembly method and characterized by X-ray crystallography. The complex exists as a three- dimensional network consisting of （AgSCN）. undulating layers linked by 4,4＇-bipy bridges.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11175033 and 10875020.
文摘We propose a more efficient and reliable scheme for transferring quantum states between distant atoms than previous schemes based on resonant atom-cavity interaction.In addition,our system can also be used to implement a controlled phase gate with high fidelity.
