This paper extends the one-dimensional(1D)nonlocal strain gradient integral model(NStraGIM)to the two-dimensional(2D)Kirchhoff axisymmetric nanoplates,based on nonlocal strain gradient integral relations formulated al...This paper extends the one-dimensional(1D)nonlocal strain gradient integral model(NStraGIM)to the two-dimensional(2D)Kirchhoff axisymmetric nanoplates,based on nonlocal strain gradient integral relations formulated along both the radial and circumferential directions.By transforming the proposed integral constitutive equations into the equivalent differential forms,complemented by the corresponding constitutive boundary conditions(CBCs),a well-posed mathematical formulation is established for analyzing the axisymmetric bending and buckling of annular/circular functionally graded(FG)sandwich nanoplates.The boundary conditions at the inner edge of a solid nanoplate are derived by L'H?spital's rule.The numerical solution is obtained by the generalized differential quadrature method(GDQM).The accuracy of the proposed model is validated through comparison with the data from the existing literature.A parameter study is conducted to demonstrate the effects of FG sandwich parameters,size parameters,and nonlocal gradient parameters.展开更多
To address the issue of disturbance compensation deviation in linear active disturbance rejection control(LADRC),a linear active disturbance rejection control method with reference to the integral chain model(LADRC-R)...To address the issue of disturbance compensation deviation in linear active disturbance rejection control(LADRC),a linear active disturbance rejection control method with reference to the integral chain model(LADRC-R)is proposed.By constructing an ideal control reference model,a dynamic correlation between output deviation and uncompensated disturbances is established,and a dual-loop compensation mechanism is designed.Based on theoretical analysis and frequency-domain characteristics of typical first/second-order systems,this method maintains the parameter-tuning advantages of LADRC while reducing disturbance effects by 50%and introducing no phase lag during low-frequency disturbance suppression.Simulations on second-order systems verify its robustness under parameter perturbations,gain mismatch,and complex disturbances,and an optimized design scheme for the deviation compensator is proposed to suppress discontinuous measurement noise interference.Finally,the engineering effectiveness of this method in precision motion control is validated on an electromagnetic suspension platform,providing a new approach to improving the control performance of LADRC in environments with uncertain disturbances.展开更多
This paper proposes an innovative form of group reduction or similarity transformation involving off-diagonal block matrices. The proposed method is applied to the Ablowitz-Kaup-Newell-Segur(AKNS) matrix spectral prob...This paper proposes an innovative form of group reduction or similarity transformation involving off-diagonal block matrices. The proposed method is applied to the Ablowitz-Kaup-Newell-Segur(AKNS) matrix spectral problem, leading to the generation of reduced matrix AKNS integrable hierarchies. As a result, a variety of reduced multiple-component integrable nonlinear Schr??dinger and modified Korteweg-de Vries models are derived from the analysis of the reduced AKNS matrix spectral problem.展开更多
Traditional Chinese medicine(TCM)is a holistic medical system that classifies and treats diseases based on the concept of patterns.These patterns describe the pathophysiological process of a disease at a specific stag...Traditional Chinese medicine(TCM)is a holistic medical system that classifies and treats diseases based on the concept of patterns.These patterns describe the pathophysiological process of a disease at a specific stage,reflecting both external signs and internal features.TCM patterns are central to pattern differentiation,treatment,clinical practice,and theoretical development in TCM.However,scientific explanation of TCM patterns remains limited because of subjective diagnostic criteria,the absence of a standardized experimental medical system,and unclear biological mechanisms,which restrict the modernization and globalization of TCM.Addressing challenges such as strong subjectivity in diagnosis,lack of standardized experimental systems,and unclear biological mechanisms is necessary to clarify the scientific meaning of TCM patterns and to provide technical approaches for the modernization and globalization of TCM.A strategy focused on“pathogenic factors,genetic predisposition,and disease progression stages”was adopted.This approach included the following:(Ⅰ)constructing disease-pattern integrated biological models with animal models,organoids,and multi-organ chips;(Ⅱ)applying multi-omics technologies,such as spatial omics,single-cell omics,and dynamic metabolic flux omics;(Ⅲ)using artificial intelligence(AI)and big data for data integration and prediction of pattern evolution;and(Ⅳ)validating formula–pattern associations through the“pattern differentiation through formula efficacy”approach.These strategies directly address the main obstacles in TCM pattern research by providing objective,quantifiable,and reproducible methodologies.Constructing disease-pattern integrated models enabled cross-scale research platforms.Applying multi-omics technologies allowed analysis of complex biological bases.AI and big data approaches addressed challenges related to heterogeneous data.The“formula-based pattern differentiation”approach supported precise interventions and the development of new drugs.This interdisciplinary framework advances TCM pattern research by moving from empirical description to objective quantification.By integrating innovative approaches,the study establishes a foundation for systematic,evidence-based TCM diagnosis and treatment,supporting accuracy and promoting international recognition and modernization of TCM.The study shows that combining multi-omics technologies,AI-driven data analysis,and disease-pattern models enables objective quantification of TCM patterns and clarifies their biological mechanisms.展开更多
Terrestrial ecosystems are vital for maintaining equilibrium in the global carbon cycle.Land use and land cover change(LUCC),which is influenced mainly by urbanization and ecological policies,impacts terrestrial ecosy...Terrestrial ecosystems are vital for maintaining equilibrium in the global carbon cycle.Land use and land cover change(LUCC),which is influenced mainly by urbanization and ecological policies,impacts terrestrial ecosystem carbon storage significantly.In this study,spatiotemporal carbon storage changes in the urban belt along the Yellow River in the Ningxia Hui Autonomous Region,China,were estimated through a model that integrated patch-generating land use simulation(PLUS)and integrated valuation of ecosystem services and tradeoffs(InVEST)models from 1993 to 2033.The results revealed that:(1)from 1993 to 2023,the expansion of built-up land and cropland was derived mainly from unused land and grassland,whereas water body and woodland remained relatively stable.Projections to 2033 have indicated that LUCC will continue and be concentrated primarily in the Ningxia Plain;(2)carbon storage increased by a net 5.01×10^(6) Mg C from 1993 to 2023;(3)the spatial distribution of carbon storage revealed that high-value areas were predominantly located in the Helan Mountains and the Ningxia Plain,whereas low-value areas were found in the Tengger Desert;(4)scenario projections indicated that by 2033,the ecological protection scenario(EPS)would achieve a 0.18×10^(6) Mg C increase by reducing the conversion of woodland to cropland and grassland to built-up land,while increasing the conversion of unused land to grassland.In contrast,the natural development scenario(NDS),cropland protection scenario(CPS),and urban development scenario(UDS)decreased carbon storage by 0.60×10^(6),0.21×10^(6),and 0.42×10^(6) Mg C,respectively;and(5)spatial autocorrelation analysis revealed that high–high carbon storage clusters formed belt-like patterns along the Ningxia Plain and the Helan Mountains,whereas the low–low carbon storage clusters were concentrated in northern Zhongwei City,western Qingtongxia City,western Dawukou District,and the urbanized areas within the central Ningxia Plain.Overall,the study results revealed the close coupling relationship between LUCC and carbon storage functions.Furthermore,the study establishes a framework for carbon management that balances ecological protection with coordinated urban development for the urban belt as well as for similar arid and semi-arid areas.On the basis of these findings,this study provides decision-makers with guidance to optimize ecosystem carbon storage via land use,which plays a key role in developing future land use policies and achieving the"dual carbon"goals.展开更多
Northwest China serves as a critical ecological barrier region for maintaining national water,energy,and food security,as well as transboundary ecological governance.However,under the dual pressures of climate change ...Northwest China serves as a critical ecological barrier region for maintaining national water,energy,and food security,as well as transboundary ecological governance.However,under the dual pressures of climate change and human activities,ecosystem services(ESs)are facing severe challenges in this region.Based on multi-source remote sensing and statistical data during 2000–2020,this study investigated the spatiotemporal evolution characteristics of four key ESs(water yield,habitat quality,carbon storage,and food provisioning)in Northwest China using the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model.Integrating morphological spatial pattern analysis(MSPA)and circuit theory,we identified ecological sources,corridors,pinch points,and barriers,and further designed three optimization scenarios(bottleneck optimization,high-resistance corridor buffering,and barrier removal optimization)to enhance landscape connectivity.The results revealed that ES supply and demand exhibited marked spatial heterogeneity,with high-supply areas concentrated in the southeastern sectors.Ecological sources primarily distributed in the southeastern and northern sectors,and ecological resistance surfaces continuously intensified.Water yield and habitat quality demands were increasing,food provisioning demand was decreasing,and carbon storage demand was surging.A total of 61 ecological sources(8%of the study area),142 ecological corridors(24,957 km in total length),237 ecological pinch points,and 89 barrier zones were identified.Among the three optimization scenarios,barrier removal achieved optimal connectivity improvement across all distance thresholds,with the probability of connectivity index improvement reaching up to 4%.This study provides scientific foundations and spatial decision support for ecological network optimization and sustainable governance in arid and semi-arid areas.展开更多
This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improveme...This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improvement at a catchment scale. The experimental field-scale wetland systems （four sets, 0.88 ha each） have been in operation since 2002, where water depth was maintained at 30-50 cm and hydraulic loading rate was at 6.3-18.8 cm/day. The wetland system was found to be adequate for treating polluted stream water with stable removal efficiency even during the winter. The integrated modeling system （modified-BASINS） was applied to the Seokmoon estuarine reservoir watershed and calibrated with monitoring data from constructed wetland, stream, and reservoir. The calibrated integrated modeling system estimated that constructing wetlands on 0.5% （about 114 ha） of the watershed area at the mouth of reservoir could reduce 11.61% and 13.49% of total external nitrogen and phosphorus loads, respectively. It also might improve the nitrogen and phosphorus concentration of the reservoir by 9.69% and 16.48%, respectively. The study suggested that about 0.1%-1.0% of the watershed area should be allocated for constructed wetland to meet specified water-quality standards for the estuarine reservoir at the polder area where land use planning is relatively less complicated.展开更多
In this work,the static tensile and free vibration of nanorods are studied via both the strain-driven(Strain D)and stress-driven(Stress D)two-phase nonlocal models with a bi-Helmholtz averaging kernel.Merely adjusting...In this work,the static tensile and free vibration of nanorods are studied via both the strain-driven(Strain D)and stress-driven(Stress D)two-phase nonlocal models with a bi-Helmholtz averaging kernel.Merely adjusting the limits of integration,the integral constitutive equation of the Fredholm type is converted to that of the Volterra type and then solved directly via the Laplace transform technique.The unknown constants can be uniquely determined through the standard boundary conditions and two constrained conditions accompanying the Laplace transform process.In the numerical examples,the bi-Helmholtz kernel-based Strain D(or Stress D)two-phase model shows consistently softening(or stiffening)effects on both the tension and the free vibration of nanorods with different boundary edges.The effects of the two nonlocal parameters of the bi-Helmholtz kernel-based two-phase nonlocal models are studied and compared with those of the Helmholtz kernel-based models.展开更多
A torsional static and free vibration analysis of the functionally graded nanotube(FGNT)composed of two materials varying continuously according to the power-law along the radial direction is performed using the bi-He...A torsional static and free vibration analysis of the functionally graded nanotube(FGNT)composed of two materials varying continuously according to the power-law along the radial direction is performed using the bi-Helmholtz kernel based stress-driven nonlocal integral model.The differential governing equation and boundary conditions are deduced on the basis of Hamilton’s principle,and the constitutive relationship is expressed as an integral equation with the bi-Helmholtz kernel.Several nominal variables are introduced to simplify the differential governing equation,integral constitutive equation,and boundary conditions.Rather than transforming the constitutive equation from integral to differential forms,the Laplace transformation is used directly to solve the integro-differential equations.The explicit expression for nominal torsional rotation and torque contains four unknown constants,which can be determined with the help of two boundary conditions and two extra constraints from the integral constitutive relation.A few benchmarked examples are solved to illustrate the nonlocal influence on the static torsion of a clamped-clamped(CC)FGNT under torsional constraints and a clamped-free(CF)FGNT under concentrated and uniformly distributed torques as well as the torsional free vibration of an FGNT under different boundary conditions.展开更多
We present a study on the dynamic stability of porous functionally graded(PFG)beams under hygro-thermal loading.The variations of the properties of the beams across the beam thicknesses are described by the power-law ...We present a study on the dynamic stability of porous functionally graded(PFG)beams under hygro-thermal loading.The variations of the properties of the beams across the beam thicknesses are described by the power-law model.Unlike most studies on this topic,we consider both the bending deformation of the beams and the hygro-thermal load as size-dependent,simultaneously,by adopting the equivalent differential forms of the well-posed nonlocal strain gradient integral theory(NSGIT)which are strictly equipped with a set of constitutive boundary conditions(CBCs),and through which both the stiffness-hardening and stiffness-softening effects of the structures can be observed with the length-scale parameters changed.All the variables presented in the differential problem formulation are discretized.The numerical solution of the dynamic instability region(DIR)of various bounded beams is then developed via the generalized differential quadrature method(GDQM).After verifying the present formulation and results,we examine the effects of different parameters such as the nonlocal/gradient length-scale parameters,the static force factor,the functionally graded(FG)parameter,and the porosity parameter on the DIR.Furthermore,the influence of considering the size-dependent hygro-thermal load is also presented.展开更多
To realize high accurate control of relative position and attitude between two spacecrafts, the coupling between position and attitude must be fully considered and a more precise model should be established. This pape...To realize high accurate control of relative position and attitude between two spacecrafts, the coupling between position and attitude must be fully considered and a more precise model should be established. This paper breaks the traditional divide and conquer idea, and uses a mathematical tool, namely dual quaternion to establish the integrated 6 degree-of-freedom(6-DOF) model of relative position and attitude, which describes the coupled relative motion in a compact and efficient form and needs less information of the target. Considering the complex operation rules and the unclarity of the current relative motion model in dual quaternion, necessary mathematical foundations are given at first, followed by clear and detailed modeling process and analysis. Finally a generalized proportion-derivative(PD) controller law is designed. The simulation results show that based on the integrated model established by dual quaternion, this control law can achieve a high control accuracy of relative motion.展开更多
Submarine landslides can cause severe damage to marine engineering structures. Their sliding velocity and runout distance are two major parameters for quantifying and analyzing the risk of submarine landslides.Current...Submarine landslides can cause severe damage to marine engineering structures. Their sliding velocity and runout distance are two major parameters for quantifying and analyzing the risk of submarine landslides.Currently, commercial calculation programs such as BING have limitations in simulating underwater soil movements. All of these processes can be consistently simulated through a smoothed particle hydrodynamics（SPH） depth integrated model. The basis of the model is a control equation that was developed to take into account the effects of soil consolidation and erosion. In this work, the frictional rheological mode has been used to perform a simulation study of submarine landslides. Time-history curves of the sliding body＇s velocity, height,and length under various conditions of water depth, slope gradient, contact friction coefficient, and erosion rate are compared; the maximum sliding distance and velocity are calculated; and patterns of variation are discussed.The findings of this study can provide a reference for disaster warnings and pipeline route selection.展开更多
Multiple Sclerosis（MS） is a major cause of neurological disability in adults and has an annual cost of approximately $28 billion in the United States. MS is a very complex disorder as demyelination can happen in a v...Multiple Sclerosis（MS） is a major cause of neurological disability in adults and has an annual cost of approximately $28 billion in the United States. MS is a very complex disorder as demyelination can happen in a variety of locations throughout the brain; therefore, this disease is never the same in two patients making it very hard to predict disease progression. A modeling approach which combines clinical, biological and imaging measures to help treat and fight this disorder is needed. In this paper, I will outline MS as a very heterogeneous disorder, review some potential solutions from the literature, demonstrate the need for a biomarker and will discuss how computational modeling combined with biological, clinical and imaging data can help link disparate observations and decipher complex mechanisms whose solutions are not amenable to simple reductionism.展开更多
An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors（a-IGZO TFTs）with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating mo...An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors（a-IGZO TFTs）with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance（C_（TI）/C_（BI））.Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.展开更多
Elucidating the structure of large biomolecules such as multi-domain proteins or protein complexes is challenging due to their high flexibility in solution. Recently, an ＂integrative structural biology＂ approach has...Elucidating the structure of large biomolecules such as multi-domain proteins or protein complexes is challenging due to their high flexibility in solution. Recently, an ＂integrative structural biology＂ approach has been proposed, which aims to determine the protein structure and characterize protein flexibility by combining complementary high- and lowresolution experimental data using computer simulations. Small-angle x-ray scattering（SAXS） is an efficient technique that can yield low-resolution structural information, including protein size and shape. Here, we review computational methods that integrate SAXS with other experimental datasets for structural modeling. Finally, we provide a case study of determination of the structure of a protein complex formed between the tandem SH3 domains in c-Cb1-associated protein and the proline-rich loop in human vinculin.展开更多
Previous studies have shown that Eringen’s differential nonlocal model would lead to the ill-posed mathematical formulation for axisymmetric bending of circular microplates.Based on the nonlocal integral models along...Previous studies have shown that Eringen’s differential nonlocal model would lead to the ill-posed mathematical formulation for axisymmetric bending of circular microplates.Based on the nonlocal integral models along the radial and circumferential directions,we propose nonlocal integral polar models in this work.The proposed strainand stress-driven two-phase nonlocal integral polar models are applied to model the axisymmetric bending of circular microplates.The governing differential equations and boundary conditions(BCs)as well as constitutive constraints are deduced.It is found that the purely strain-driven nonlocal integral polar model turns to a traditional nonlocal differential polar model if the constitutive constraints are neglected.Meanwhile,the purely strain-and stress-driven nonlocal integral polar models are ill-posed,because the total number of the differential orders of the governing equations is less than that of the BCs plus constitutive constraints.Several nominal variables are introduced to simplify the mathematical expression,and the general differential quadrature method(GDQM)is applied to obtain the numerical solutions.The results from the current models(CMs)are compared with the data in the literature.It is clearly established that the consistent softening and toughening effects can be obtained for the strain-and stress-driven local/nonlocal integral polar models,respectively.The proposed two-phase local/nonlocal integral polar models(TPNIPMs)may provide an efficient method to design and optimize the plate-like structures for microelectro-mechanical systems.展开更多
In this paper,we propose general strain-and stress-driven two-phase local/nonlocal piezoelectric integral models,which can distinguish the difference of nonlocal effects on the elastic and piezoelectric behaviors of n...In this paper,we propose general strain-and stress-driven two-phase local/nonlocal piezoelectric integral models,which can distinguish the difference of nonlocal effects on the elastic and piezoelectric behaviors of nanostructures.The nonlocal piezoelectric model is transformed from integral to an equivalent differential form with four constitutive boundary conditions due to the difficulty in solving intergro-differential equations directly.The nonlocal piezoelectric integral models are used to model the static bending of the Euler-Bernoulli piezoelectric beam on the assumption that the nonlocal elastic and piezoelectric parameters are coincident with each other.The governing differential equations as well as constitutive and standard boundary conditions are deduced.It is found that purely strain-and stress-driven nonlocal piezoelectric integral models are ill-posed,because the total number of differential orders for governing equations is less than that of boundary conditions.Meanwhile,the traditional nonlocal piezoelectric differential model would lead to inconsistent bending response for Euler-Bernoulli piezoelectric beam under different boundary and loading conditions.Several nominal variables are introduced to normalize the governing equations and boundary conditions,and the general differential quadrature method(GDQM)is used to obtain the numerical solutions.The results from current models are validated against results in the literature.It is clearly established that a consistent softening and toughening effects can be obtained for static bending of the Euler-Bernoulli beam based on the general strain-and stress-driven local/nonlocal piezoelectric integral models,respectively.展开更多
Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table ris...Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table rises in soils, which are significantly faster and higher than those in soils without air entrapment. Two numerical models, Integrated Hydrologic Model (IHM) and HYDRUS-1D (a single-phase, one-dimensional Richards′ equation model) were tested at an area of west central Florida to help further understanding the shallow water table behavior during a long term air entrapment. This investigation employed field data with two modeling approaches to quantify the variation of air pressurization values. It was found that the air pressurization effect was responsible at time up to 40 cm of water table rise being recorded by the observation well for these two models. The values of air pressurization calculated from IHM and HYDRUS-1D match the previously published values. Results also indicated that the two numerical models did not consider air entrapment effect (as the predictive parameters remain uncertain) and thus results of depth to water table from these models did not compare to the observations for these selected periods. Incorporating air entrapment in prediction models is critical to reproduce shallow water table observations.展开更多
We prove a local existence of a strong solution v ：Ω×T→R^3 for a system of nonlinear integrodifferential equations describing motion of an incompressible viscoelastic fluid using standard mathematical tools. T...We prove a local existence of a strong solution v ：Ω×T→R^3 for a system of nonlinear integrodifferential equations describing motion of an incompressible viscoelastic fluid using standard mathematical tools. The problem is considered in a bounded, smooth domain ΩСR^3 with a Dirichlet boundary condition and a standard initial condition.展开更多
The grey system theory, with the characteristics of fewer modeling data and higher accuracy, was employed to model the batch dyeing process for the purpose of accurate online control. The GM（1, 1） and GM （0, N） mo...The grey system theory, with the characteristics of fewer modeling data and higher accuracy, was employed to model the batch dyeing process for the purpose of accurate online control. The GM（1, 1） and GM （0, N） models of the grey system theory were discussed for their feasibilities of modding for batch dyeing process. The combination of direct dyestuff Fast Red F3B on cotton was chosen as a representative of the common dyeing method for describing the modeling process. Firstly, the GM（ 1, 1 ） model and the GM（1, 1） combined with GM（0, N） model were employed to model the equilibrium percentage of dyeing uptake rate. Secondly, an integrated dyeing uptake rate model with three factors （ temperature, salt concentration, and pH） was established based on the adsorption rate equation. Experimental results show that this model has higher accuracy and beetler generalization ability, which can predict the results of batch dyeing process. Due to the application of grey system theory, the model has a lot of advantages, such as being easy to determine the parameter value and small amount of calculation. So it can also be suitable for the same type of combination of dyestuff-fahric by changing the parameters value only.展开更多
基金Project supported by the National Natural Science Foundation of China(No.12172169)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘This paper extends the one-dimensional(1D)nonlocal strain gradient integral model(NStraGIM)to the two-dimensional(2D)Kirchhoff axisymmetric nanoplates,based on nonlocal strain gradient integral relations formulated along both the radial and circumferential directions.By transforming the proposed integral constitutive equations into the equivalent differential forms,complemented by the corresponding constitutive boundary conditions(CBCs),a well-posed mathematical formulation is established for analyzing the axisymmetric bending and buckling of annular/circular functionally graded(FG)sandwich nanoplates.The boundary conditions at the inner edge of a solid nanoplate are derived by L'H?spital's rule.The numerical solution is obtained by the generalized differential quadrature method(GDQM).The accuracy of the proposed model is validated through comparison with the data from the existing literature.A parameter study is conducted to demonstrate the effects of FG sandwich parameters,size parameters,and nonlocal gradient parameters.
基金supported by the National Natural Science Foundation of China(Nos.62063009,52262050)the National Key Research and Development Program during the 14th 5-Year Plan(No.2023YFB4302100)the Major Science and Technology Research and Development Special Project in Jiangxi Province(No.20232ACE01011).
文摘To address the issue of disturbance compensation deviation in linear active disturbance rejection control(LADRC),a linear active disturbance rejection control method with reference to the integral chain model(LADRC-R)is proposed.By constructing an ideal control reference model,a dynamic correlation between output deviation and uncompensated disturbances is established,and a dual-loop compensation mechanism is designed.Based on theoretical analysis and frequency-domain characteristics of typical first/second-order systems,this method maintains the parameter-tuning advantages of LADRC while reducing disturbance effects by 50%and introducing no phase lag during low-frequency disturbance suppression.Simulations on second-order systems verify its robustness under parameter perturbations,gain mismatch,and complex disturbances,and an optimized design scheme for the deviation compensator is proposed to suppress discontinuous measurement noise interference.Finally,the engineering effectiveness of this method in precision motion control is validated on an electromagnetic suspension platform,providing a new approach to improving the control performance of LADRC in environments with uncertain disturbances.
基金supported in part by the Ministry of Science and Technology of China (G2021016032L and G2023016011L)the National Natural Science Foundation of China (12271488 and 11975145)。
文摘This paper proposes an innovative form of group reduction or similarity transformation involving off-diagonal block matrices. The proposed method is applied to the Ablowitz-Kaup-Newell-Segur(AKNS) matrix spectral problem, leading to the generation of reduced matrix AKNS integrable hierarchies. As a result, a variety of reduced multiple-component integrable nonlinear Schr??dinger and modified Korteweg-de Vries models are derived from the analysis of the reduced AKNS matrix spectral problem.
基金supported by the National Key Research and Development Program of China(2022YFC3500100)the National Natural Science Foundation of China(82230126 and U24A20800)+3 种基金Noncommunicable Chronic Diseases-National Science and Technology Major Project(2023ZD0502600 and 2023ZD0502601)National Science Fund for Excellent Young Scholars(82222075)the Incubation Program for the Science and Technology Development of Chinese Medicine Guangdong Laboratory(HQL2024PZ045 and HQCML-C-2024003)Guangdong Provincial Key Laboratory of Pattern and Formula(2022B1212010012).
文摘Traditional Chinese medicine(TCM)is a holistic medical system that classifies and treats diseases based on the concept of patterns.These patterns describe the pathophysiological process of a disease at a specific stage,reflecting both external signs and internal features.TCM patterns are central to pattern differentiation,treatment,clinical practice,and theoretical development in TCM.However,scientific explanation of TCM patterns remains limited because of subjective diagnostic criteria,the absence of a standardized experimental medical system,and unclear biological mechanisms,which restrict the modernization and globalization of TCM.Addressing challenges such as strong subjectivity in diagnosis,lack of standardized experimental systems,and unclear biological mechanisms is necessary to clarify the scientific meaning of TCM patterns and to provide technical approaches for the modernization and globalization of TCM.A strategy focused on“pathogenic factors,genetic predisposition,and disease progression stages”was adopted.This approach included the following:(Ⅰ)constructing disease-pattern integrated biological models with animal models,organoids,and multi-organ chips;(Ⅱ)applying multi-omics technologies,such as spatial omics,single-cell omics,and dynamic metabolic flux omics;(Ⅲ)using artificial intelligence(AI)and big data for data integration and prediction of pattern evolution;and(Ⅳ)validating formula–pattern associations through the“pattern differentiation through formula efficacy”approach.These strategies directly address the main obstacles in TCM pattern research by providing objective,quantifiable,and reproducible methodologies.Constructing disease-pattern integrated models enabled cross-scale research platforms.Applying multi-omics technologies allowed analysis of complex biological bases.AI and big data approaches addressed challenges related to heterogeneous data.The“formula-based pattern differentiation”approach supported precise interventions and the development of new drugs.This interdisciplinary framework advances TCM pattern research by moving from empirical description to objective quantification.By integrating innovative approaches,the study establishes a foundation for systematic,evidence-based TCM diagnosis and treatment,supporting accuracy and promoting international recognition and modernization of TCM.The study shows that combining multi-omics technologies,AI-driven data analysis,and disease-pattern models enables objective quantification of TCM patterns and clarifies their biological mechanisms.
基金supported by the National Natural Sciences Foundation of China(42261026)the Open Foundation of Xinjiang Key Laboratory of Water Cycle and Utilization in Arid Zone(XJYS0907-2023-01)the Light of the West Program for Young Scholars,Chinese Academy of Sciences(25JR6KA005).
文摘Terrestrial ecosystems are vital for maintaining equilibrium in the global carbon cycle.Land use and land cover change(LUCC),which is influenced mainly by urbanization and ecological policies,impacts terrestrial ecosystem carbon storage significantly.In this study,spatiotemporal carbon storage changes in the urban belt along the Yellow River in the Ningxia Hui Autonomous Region,China,were estimated through a model that integrated patch-generating land use simulation(PLUS)and integrated valuation of ecosystem services and tradeoffs(InVEST)models from 1993 to 2033.The results revealed that:(1)from 1993 to 2023,the expansion of built-up land and cropland was derived mainly from unused land and grassland,whereas water body and woodland remained relatively stable.Projections to 2033 have indicated that LUCC will continue and be concentrated primarily in the Ningxia Plain;(2)carbon storage increased by a net 5.01×10^(6) Mg C from 1993 to 2023;(3)the spatial distribution of carbon storage revealed that high-value areas were predominantly located in the Helan Mountains and the Ningxia Plain,whereas low-value areas were found in the Tengger Desert;(4)scenario projections indicated that by 2033,the ecological protection scenario(EPS)would achieve a 0.18×10^(6) Mg C increase by reducing the conversion of woodland to cropland and grassland to built-up land,while increasing the conversion of unused land to grassland.In contrast,the natural development scenario(NDS),cropland protection scenario(CPS),and urban development scenario(UDS)decreased carbon storage by 0.60×10^(6),0.21×10^(6),and 0.42×10^(6) Mg C,respectively;and(5)spatial autocorrelation analysis revealed that high–high carbon storage clusters formed belt-like patterns along the Ningxia Plain and the Helan Mountains,whereas the low–low carbon storage clusters were concentrated in northern Zhongwei City,western Qingtongxia City,western Dawukou District,and the urbanized areas within the central Ningxia Plain.Overall,the study results revealed the close coupling relationship between LUCC and carbon storage functions.Furthermore,the study establishes a framework for carbon management that balances ecological protection with coordinated urban development for the urban belt as well as for similar arid and semi-arid areas.On the basis of these findings,this study provides decision-makers with guidance to optimize ecosystem carbon storage via land use,which plays a key role in developing future land use policies and achieving the"dual carbon"goals.
基金supported by the Tianchi Talent Introduction Program of Xinjiang Uygur Autonomous Region(2024000104)the National Key Research and Development Program of China(2023YFF0805603).
文摘Northwest China serves as a critical ecological barrier region for maintaining national water,energy,and food security,as well as transboundary ecological governance.However,under the dual pressures of climate change and human activities,ecosystem services(ESs)are facing severe challenges in this region.Based on multi-source remote sensing and statistical data during 2000–2020,this study investigated the spatiotemporal evolution characteristics of four key ESs(water yield,habitat quality,carbon storage,and food provisioning)in Northwest China using the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST)model.Integrating morphological spatial pattern analysis(MSPA)and circuit theory,we identified ecological sources,corridors,pinch points,and barriers,and further designed three optimization scenarios(bottleneck optimization,high-resistance corridor buffering,and barrier removal optimization)to enhance landscape connectivity.The results revealed that ES supply and demand exhibited marked spatial heterogeneity,with high-supply areas concentrated in the southeastern sectors.Ecological sources primarily distributed in the southeastern and northern sectors,and ecological resistance surfaces continuously intensified.Water yield and habitat quality demands were increasing,food provisioning demand was decreasing,and carbon storage demand was surging.A total of 61 ecological sources(8%of the study area),142 ecological corridors(24,957 km in total length),237 ecological pinch points,and 89 barrier zones were identified.Among the three optimization scenarios,barrier removal achieved optimal connectivity improvement across all distance thresholds,with the probability of connectivity index improvement reaching up to 4%.This study provides scientific foundations and spatial decision support for ecological network optimization and sustainable governance in arid and semi-arid areas.
文摘This article describes the integrated modeling approach for planning the size and the operation of constructed wetlands for maximizing retention of nonpoint source pollutant loads and reservoir water-quality improvement at a catchment scale. The experimental field-scale wetland systems （four sets, 0.88 ha each） have been in operation since 2002, where water depth was maintained at 30-50 cm and hydraulic loading rate was at 6.3-18.8 cm/day. The wetland system was found to be adequate for treating polluted stream water with stable removal efficiency even during the winter. The integrated modeling system （modified-BASINS） was applied to the Seokmoon estuarine reservoir watershed and calibrated with monitoring data from constructed wetland, stream, and reservoir. The calibrated integrated modeling system estimated that constructing wetlands on 0.5% （about 114 ha） of the watershed area at the mouth of reservoir could reduce 11.61% and 13.49% of total external nitrogen and phosphorus loads, respectively. It also might improve the nitrogen and phosphorus concentration of the reservoir by 9.69% and 16.48%, respectively. The study suggested that about 0.1%-1.0% of the watershed area should be allocated for constructed wetland to meet specified water-quality standards for the estuarine reservoir at the polder area where land use planning is relatively less complicated.
基金the National Natural Science Foundation of China(No.12172169)the China Scholarship Council(CSC)(No.202006830038)。
文摘In this work,the static tensile and free vibration of nanorods are studied via both the strain-driven(Strain D)and stress-driven(Stress D)two-phase nonlocal models with a bi-Helmholtz averaging kernel.Merely adjusting the limits of integration,the integral constitutive equation of the Fredholm type is converted to that of the Volterra type and then solved directly via the Laplace transform technique.The unknown constants can be uniquely determined through the standard boundary conditions and two constrained conditions accompanying the Laplace transform process.In the numerical examples,the bi-Helmholtz kernel-based Strain D(or Stress D)two-phase model shows consistently softening(or stiffening)effects on both the tension and the free vibration of nanorods with different boundary edges.The effects of the two nonlocal parameters of the bi-Helmholtz kernel-based two-phase nonlocal models are studied and compared with those of the Helmholtz kernel-based models.
基金Project supported by the National Natural Science Foundation of China(No.11672131)the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘A torsional static and free vibration analysis of the functionally graded nanotube(FGNT)composed of two materials varying continuously according to the power-law along the radial direction is performed using the bi-Helmholtz kernel based stress-driven nonlocal integral model.The differential governing equation and boundary conditions are deduced on the basis of Hamilton’s principle,and the constitutive relationship is expressed as an integral equation with the bi-Helmholtz kernel.Several nominal variables are introduced to simplify the differential governing equation,integral constitutive equation,and boundary conditions.Rather than transforming the constitutive equation from integral to differential forms,the Laplace transformation is used directly to solve the integro-differential equations.The explicit expression for nominal torsional rotation and torque contains four unknown constants,which can be determined with the help of two boundary conditions and two extra constraints from the integral constitutive relation.A few benchmarked examples are solved to illustrate the nonlocal influence on the static torsion of a clamped-clamped(CC)FGNT under torsional constraints and a clamped-free(CF)FGNT under concentrated and uniformly distributed torques as well as the torsional free vibration of an FGNT under different boundary conditions.
基金Project supported by the National Natural Science Foundation of China(No.12172169)the Natural Sciences and Engineering Research Council of Canada(No.NSERC RGPIN-2023-03227)。
文摘We present a study on the dynamic stability of porous functionally graded(PFG)beams under hygro-thermal loading.The variations of the properties of the beams across the beam thicknesses are described by the power-law model.Unlike most studies on this topic,we consider both the bending deformation of the beams and the hygro-thermal load as size-dependent,simultaneously,by adopting the equivalent differential forms of the well-posed nonlocal strain gradient integral theory(NSGIT)which are strictly equipped with a set of constitutive boundary conditions(CBCs),and through which both the stiffness-hardening and stiffness-softening effects of the structures can be observed with the length-scale parameters changed.All the variables presented in the differential problem formulation are discretized.The numerical solution of the dynamic instability region(DIR)of various bounded beams is then developed via the generalized differential quadrature method(GDQM).After verifying the present formulation and results,we examine the effects of different parameters such as the nonlocal/gradient length-scale parameters,the static force factor,the functionally graded(FG)parameter,and the porosity parameter on the DIR.Furthermore,the influence of considering the size-dependent hygro-thermal load is also presented.
基金supported by the National Natural Science Foundation of China(6107412761427809)
文摘To realize high accurate control of relative position and attitude between two spacecrafts, the coupling between position and attitude must be fully considered and a more precise model should be established. This paper breaks the traditional divide and conquer idea, and uses a mathematical tool, namely dual quaternion to establish the integrated 6 degree-of-freedom(6-DOF) model of relative position and attitude, which describes the coupled relative motion in a compact and efficient form and needs less information of the target. Considering the complex operation rules and the unclarity of the current relative motion model in dual quaternion, necessary mathematical foundations are given at first, followed by clear and detailed modeling process and analysis. Finally a generalized proportion-derivative(PD) controller law is designed. The simulation results show that based on the integrated model established by dual quaternion, this control law can achieve a high control accuracy of relative motion.
基金The Specialized Research Fund for the Doctoral Program of Higher Education under contract No.20120041130002the National Key Project of Science and Technology under contract No.2011ZX 05056-001-02the Fundamental Research Funds for the Central Universities under contract No.DUT14ZD220
文摘Submarine landslides can cause severe damage to marine engineering structures. Their sliding velocity and runout distance are two major parameters for quantifying and analyzing the risk of submarine landslides.Currently, commercial calculation programs such as BING have limitations in simulating underwater soil movements. All of these processes can be consistently simulated through a smoothed particle hydrodynamics（SPH） depth integrated model. The basis of the model is a control equation that was developed to take into account the effects of soil consolidation and erosion. In this work, the frictional rheological mode has been used to perform a simulation study of submarine landslides. Time-history curves of the sliding body＇s velocity, height,and length under various conditions of water depth, slope gradient, contact friction coefficient, and erosion rate are compared; the maximum sliding distance and velocity are calculated; and patterns of variation are discussed.The findings of this study can provide a reference for disaster warnings and pipeline route selection.
文摘Multiple Sclerosis（MS） is a major cause of neurological disability in adults and has an annual cost of approximately $28 billion in the United States. MS is a very complex disorder as demyelination can happen in a variety of locations throughout the brain; therefore, this disease is never the same in two patients making it very hard to predict disease progression. A modeling approach which combines clinical, biological and imaging measures to help treat and fight this disorder is needed. In this paper, I will outline MS as a very heterogeneous disorder, review some potential solutions from the literature, demonstrate the need for a biomarker and will discuss how computational modeling combined with biological, clinical and imaging data can help link disparate observations and decipher complex mechanisms whose solutions are not amenable to simple reductionism.
基金Supported by the National Key Research and Development Program of China under Grant No 2017YFA0204600the National Natural Science Foundation of China under Grant No 61404002the Science and Technology Project of Hunan Province under Grant No 2015JC3041
文摘An analytical model for current-voltage behavior of amorphous In-Ga-Zn-O thin-film transistors（a-IGZO TFTs）with dual-gate structures is developed.The unified expressions for synchronous and asynchronous operating modes are derived on the basis of channel charges,which are controlled by gate voltage.It is proven that the threshold voltage of asynchronous dual-gate IGZO TFTs is adjusted in proportion to the ratio of top insulating capacitance to the bottom insulating capacitance（C_（TI）/C_（BI））.Incorporating the proposed model with Verilog-A,a touch-sensing circuit using dual-gate structure is investigated by SPICE simulations.Comparison shows that the touch sensitivity is increased by the dual-gate IGZO TFT structure.
基金Project supported by the National Key Basic Research Program of China(Grant Nos.2013CB910203 and 2011CB911104)the National Natural Science Foundation of China(Grant No.31270760)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB08030102)the Specialized Research Fund for the Doctoral Program of Higher Education of China(Grant No.20113402120013)
文摘Elucidating the structure of large biomolecules such as multi-domain proteins or protein complexes is challenging due to their high flexibility in solution. Recently, an ＂integrative structural biology＂ approach has been proposed, which aims to determine the protein structure and characterize protein flexibility by combining complementary high- and lowresolution experimental data using computer simulations. Small-angle x-ray scattering（SAXS） is an efficient technique that can yield low-resolution structural information, including protein size and shape. Here, we review computational methods that integrate SAXS with other experimental datasets for structural modeling. Finally, we provide a case study of determination of the structure of a protein complex formed between the tandem SH3 domains in c-Cb1-associated protein and the proline-rich loop in human vinculin.
基金Project supported by the National Natural Science Foundation of China(No.12172169)the Research Fund of State Key Laboratory of Mechanicsthe Priority Academic Program Development of Jiangsu Higher Education Institutions of China。
文摘Previous studies have shown that Eringen’s differential nonlocal model would lead to the ill-posed mathematical formulation for axisymmetric bending of circular microplates.Based on the nonlocal integral models along the radial and circumferential directions,we propose nonlocal integral polar models in this work.The proposed strainand stress-driven two-phase nonlocal integral polar models are applied to model the axisymmetric bending of circular microplates.The governing differential equations and boundary conditions(BCs)as well as constitutive constraints are deduced.It is found that the purely strain-driven nonlocal integral polar model turns to a traditional nonlocal differential polar model if the constitutive constraints are neglected.Meanwhile,the purely strain-and stress-driven nonlocal integral polar models are ill-posed,because the total number of the differential orders of the governing equations is less than that of the BCs plus constitutive constraints.Several nominal variables are introduced to simplify the mathematical expression,and the general differential quadrature method(GDQM)is applied to obtain the numerical solutions.The results from the current models(CMs)are compared with the data in the literature.It is clearly established that the consistent softening and toughening effects can be obtained for the strain-and stress-driven local/nonlocal integral polar models,respectively.The proposed two-phase local/nonlocal integral polar models(TPNIPMs)may provide an efficient method to design and optimize the plate-like structures for microelectro-mechanical systems.
基金the National Natural Science Foundation of China(No.12172169)the Scholarship of the China Scholarship Council(No.202106830093)。
文摘In this paper,we propose general strain-and stress-driven two-phase local/nonlocal piezoelectric integral models,which can distinguish the difference of nonlocal effects on the elastic and piezoelectric behaviors of nanostructures.The nonlocal piezoelectric model is transformed from integral to an equivalent differential form with four constitutive boundary conditions due to the difficulty in solving intergro-differential equations directly.The nonlocal piezoelectric integral models are used to model the static bending of the Euler-Bernoulli piezoelectric beam on the assumption that the nonlocal elastic and piezoelectric parameters are coincident with each other.The governing differential equations as well as constitutive and standard boundary conditions are deduced.It is found that purely strain-and stress-driven nonlocal piezoelectric integral models are ill-posed,because the total number of differential orders for governing equations is less than that of boundary conditions.Meanwhile,the traditional nonlocal piezoelectric differential model would lead to inconsistent bending response for Euler-Bernoulli piezoelectric beam under different boundary and loading conditions.Several nominal variables are introduced to normalize the governing equations and boundary conditions,and the general differential quadrature method(GDQM)is used to obtain the numerical solutions.The results from current models are validated against results in the literature.It is clearly established that a consistent softening and toughening effects can be obtained for static bending of the Euler-Bernoulli beam based on the general strain-and stress-driven local/nonlocal piezoelectric integral models,respectively.
基金Under the auspices of National Natural Science Foundation of China (No. 40901026)International Cooperation Project of Ministry of Science and Technology of China (No. 2010DFA92400)Tampa Bay Water and South Florida Water Management District (TBW and SFWMD) Project
文摘Air entrapment is an important consideration in environments with shallow water tables and sandy soil, like the condition of highly conductive sandy soils and flat topography in Florida, USA. It causes water table rises in soils, which are significantly faster and higher than those in soils without air entrapment. Two numerical models, Integrated Hydrologic Model (IHM) and HYDRUS-1D (a single-phase, one-dimensional Richards′ equation model) were tested at an area of west central Florida to help further understanding the shallow water table behavior during a long term air entrapment. This investigation employed field data with two modeling approaches to quantify the variation of air pressurization values. It was found that the air pressurization effect was responsible at time up to 40 cm of water table rise being recorded by the observation well for these two models. The values of air pressurization calculated from IHM and HYDRUS-1D match the previously published values. Results also indicated that the two numerical models did not consider air entrapment effect (as the predictive parameters remain uncertain) and thus results of depth to water table from these models did not compare to the observations for these selected periods. Incorporating air entrapment in prediction models is critical to reproduce shallow water table observations.
基金supported by Grant Agency of the Charles University(454213)
文摘We prove a local existence of a strong solution v ：Ω×T→R^3 for a system of nonlinear integrodifferential equations describing motion of an incompressible viscoelastic fluid using standard mathematical tools. The problem is considered in a bounded, smooth domain ΩСR^3 with a Dirichlet boundary condition and a standard initial condition.
基金National Natural Science Foundation of China(No.61074154)
文摘The grey system theory, with the characteristics of fewer modeling data and higher accuracy, was employed to model the batch dyeing process for the purpose of accurate online control. The GM（1, 1） and GM （0, N） models of the grey system theory were discussed for their feasibilities of modding for batch dyeing process. The combination of direct dyestuff Fast Red F3B on cotton was chosen as a representative of the common dyeing method for describing the modeling process. Firstly, the GM（ 1, 1 ） model and the GM（1, 1） combined with GM（0, N） model were employed to model the equilibrium percentage of dyeing uptake rate. Secondly, an integrated dyeing uptake rate model with three factors （ temperature, salt concentration, and pH） was established based on the adsorption rate equation. Experimental results show that this model has higher accuracy and beetler generalization ability, which can predict the results of batch dyeing process. Due to the application of grey system theory, the model has a lot of advantages, such as being easy to determine the parameter value and small amount of calculation. So it can also be suitable for the same type of combination of dyestuff-fahric by changing the parameters value only.
