Data reconstruction is a crucial step in seismic data preprocessing.To improve reconstruction speed and save memory,the commonly used three-dimensional(3D)seismic data reconstruction method divides the missing data in...Data reconstruction is a crucial step in seismic data preprocessing.To improve reconstruction speed and save memory,the commonly used three-dimensional(3D)seismic data reconstruction method divides the missing data into a series of time slices and independently reconstructs each time slice.However,when this strategy is employed,the potential correlations between two adjacent time slices are ignored,which degrades reconstruction performance.Therefore,this study proposes the use of a two-dimensional curvelet transform and the fast iterative shrinkage thresholding algorithm for data reconstruction.Based on the significant overlapping characteristics between the curvelet coefficient support sets of two adjacent time slices,a weighted operator is constructed in the curvelet domain using the prior support set provided by the previous reconstructed time slice to delineate the main energy distribution range,eff ectively providing prior information for reconstructing adjacent slices.Consequently,the resulting weighted fast iterative shrinkage thresholding algorithm can be used to reconstruct 3D seismic data.The processing of synthetic and field data shows that the proposed method has higher reconstruction accuracy and faster computational speed than the conventional fast iterative shrinkage thresholding algorithm for handling missing 3D seismic data.展开更多
The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix sp...The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix splitting methods.Taking the decomposition of the diagonal elements for coefficient matrix as the key point,some new preconditioners are constructed.Taking the tri-diagonal coefficient matrix as an example,the convergence domains and optimal relaxation factor of the new method are analyzed theoretically.The presented new iteration methods are applied to solve linear algebraic equations,even 2D and 3D diffusion problems with the fully implicit discretization.The results of numerical experiments are matched with the theoretical analysis,and show that the iteration numbers are reduced greatly.The superiorities of presented iteration methods exceed some classical iteration methods dramatically.展开更多
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ...In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.展开更多
Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this...Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this issue by investigating the efficacy of silica fume(SF)and fly ash(FA),individually and combined,in controlling the shrinkage deformation of shotcrete.Design/methodology/approach-Shotcrete mixtures were prepared with cement partially replaced by SF,FA,or their combination(SF-FA).Aluminum sulfate was used as an accelerator.The shrinkage behavior under sealed and dry conditions was monitored.The underlying mechanisms were elucidated through hardened airvoid analysis,mercury intrusion porosimetry(MIP),and internal humidity tracking.Findings-Contrary to some previous studies,both individual and combined incorporation of mineral admixtures reduced the 28-day shrinkage.The SF-FA composite exhibited the most substantial reduction(23.72%sealed,17.76%dry),followed by SF alone(18.11%sealed)and FA alone(11.35%sealed).Mechanism analysis revealed that the admixtures refined the pore structure,reduced the volume of harmful pores,and,crucially,optimized the air-void system by increasing the population of fine bubbles.This created an internal buffering effect that alleviates capillary stress.The synergistic effect in the SF-FA group is attributed to complementary pore-filling at dual scales.Originality/value-This work demonstrates that,within an aluminum sulfate-accelerated shotcrete system,silica fume can effectively reduce shrinkage when its pore-refining effect is counterbalanced by a welloptimized micro-bubble network.It provides the first comprehensive evidence of the synergistic shrinkagereducing mechanism of SF and FA in such systems,offering a practical strategy for mix design optimization to enhance the volume stability of shotcrete.展开更多
This study aimed to investigate the influence of recycled sand(RS)content and water-binder ratio on the long term performance of recycled sand concrete(RSC).A 220 days drying shrinkage and creep test of RSC was conduc...This study aimed to investigate the influence of recycled sand(RS)content and water-binder ratio on the long term performance of recycled sand concrete(RSC).A 220 days drying shrinkage and creep test of RSC was conducted,and the microhardness of ITZ were analyzed to explain the differences in performance.The experimental results indicate that,when RS content is 50%,the drying shrinkage and creep strain of RSC is the smallest.This is attributed to the highest microhardness in the ITZ when the RS content is 50%.When the RS content is 100%,the shrinkage and creep strains increase due to the high water absorption of RS,which leads to the evaporation of additional water and the deterioration of the ITZ.As the water-binder ratio increases,the drying shrinkage and creep strain of RSC with different RS content increases.According to the EC2 specification and the CEB-FIP specification,the drying shrinkage and creep prediction models for RSC have been established.展开更多
Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LE...Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LEDs are predominantly thermally cured,which is energy-and time-consuming and can adversely affect electronic components.In this study,a novel UV-curable silicone resin containing phenyl,disulfide,and acryloyl groups(SPASR)is developed from commercially available siloxanes.The resin exhibits a refractive index(n_(d))higher than 1.5,and it can be cured within 30 s under UV irradiation.After curing,it exhibits an optical transparency exceeding 92%,a lap adhesion strength of up to1.84 MPa,and good thermostability(T_(5%)>265℃).Notably,the volume shrinkage is less than 4.83%,attributed to the release of photopolymerization stress via UV-induced disulfide metathesis during UV curing.Mini-LEDs encapsulated with this resin show luminescence properties comparable to those of conventional thermally-cured sealants,and show excellent sealability wihtout visible penetration after being immersed in red ink for 12 h.Consequently,these excellent properties make the SPASR resin an ideal candidate for microelectronic encapsulation,offering a more reliable and efficient solution for the electronics industry.展开更多
The dependence of shrinkage porosities on microstructure characteristics of Mg−12Al alloy was investigated.The distribution,morphology,size,and number density of shrinkage porosities were analyzed under different cool...The dependence of shrinkage porosities on microstructure characteristics of Mg−12Al alloy was investigated.The distribution,morphology,size,and number density of shrinkage porosities were analyzed under different cooling rates.The relationship between shrinkage porosities and microstructure characteristics was discussed in terms of temperature conditions,feeding channel characteristics,and feeding capacity.Further,the feeding behavior of the residual liquid phase in the solid skeleton was quantified by introducing permeability.Results show a strong correlation between the solid microstructure skeleton and shrinkage porosity characteristics.An increase in permeability corresponds to a declining number density of shrinkage porosities.This study aims to provide a more complete understanding how to reduce shrinkage porosities by controlling microstructure characteristics.展开更多
Deep learning methods have achieved significant progress in solving partial differential equations.However,when applied to the widely used anisotropic scattering neutron transport equations in reactor engineering,thes...Deep learning methods have achieved significant progress in solving partial differential equations.However,when applied to the widely used anisotropic scattering neutron transport equations in reactor engineering,these encounter significant challenges.To address this issue,this study introduces a multi-antiderivative transformation alternating iterative deep learning method(M-AIM).This method transforms the integral terms of the scattering and fission sources in the transport equation into multiple antiderivative functions corresponding to the integrand,converts the differential-integral form of the transport equation into an exact differential equation,and establishes the necessary constraints for a unique solution.The M-AIM uses multiple deep neural networks to map the unknown angular flux density of transport equations and represents various forms of antiderivative functions.It constructs the corresponding weighted loss functions.By alternating iterative training with deep learning methods applied to these neural networks,the loss is reduced gradually.When the loss decreases to a preset minimum,the neural network approaches a numerical solution for both angular flux density and antiderivative functions.This paper presents a numerical verification of geometries such as flat plates and spheres.It verifies the validity of the theoretical framework and associated methods.The study contributes to the development of novel technical approaches for applying deep learning to solve anisotropic scattering neutron transport equations in reactor engineering.展开更多
Iterative Learning Control(ILC)provides an effective framework for optimizing repetitive tasks,making it particularly suitable for high-precision applications in both precision manufacturing and intelligent transporta...Iterative Learning Control(ILC)provides an effective framework for optimizing repetitive tasks,making it particularly suitable for high-precision applications in both precision manufacturing and intelligent transportation systems(ITS).This paper presents a systematic review of ILC's developmental progress,current methodologies,and practical implementations across these two critical domains.The review first analyzes the key technical challenges encountered when integrating ILC into precision manufacturing workflows.Through case studies,it evaluates demonstrated improvements in positioning accuracy,surface finish quality,and production throughput.Furthermore,the study examines ILC’s applications in ITS,with particular focus on vehicular motion control applications including autonomous vehicle trajectory tracking,platoon coordination,and traffic signal timing optimization,where its data-driven characteristics enhance adaptability to dynamic environments.Finally,the paper proposes targeted future research directions that are essential for fully realizing ILC’s potential in advancing these interconnected yet distinct fields.展开更多
The iterative continuation task(ICT)requires English as a foreign language(EFL)learners to read a segment and write a continuation that aligns with the preceding segment of an English novel with successive turns,offer...The iterative continuation task(ICT)requires English as a foreign language(EFL)learners to read a segment and write a continuation that aligns with the preceding segment of an English novel with successive turns,offering exposure to diverse grammatical structures and opportunities for contextualized usage.Given the importance of integrating technology into second language(L2)writing and the critical role that grammar plays in L2 writing development,automated written corrective feedback provided by Grammarly has gained significant attention.This study investigates the impact of Grammarly on grammar learning strategies,grammar grit,and grammar competence among EFL college students engaged in ICT.This study employed a mixed-methods sequential exploratory design;56 participants were divided into an experimental group(n=28),receiving Grammarly feedback for ICT,and a control group(n=28),completing ICT without Grammarly feedback.Quantitative results revealed that both groups showed improvements in L2 grammar learning strategies,grit and competence.For the experimental group,significant differences were observed across all variables of L2 grammar learning strategies,grit,and competence between pre-and post-tests.For the control group,significant differences were only observed in the affective dimension of grammar learning strategies,Consistency of Interest(COI)of grammar grit,and grammar competence.However,the control group presented a significantly higher improvement in grammar competence.Qualitative analysis showed both positive and negative perceptions of Grammarly.The pedagogical implications of integrating Grammarly and ICT for L2 grammar development are discussed.展开更多
Due to the digital transformation tendency among cultural institutions and the substantial influence of the social media platform,the demands of visual communication keep increasing for promoting traditional cultural ...Due to the digital transformation tendency among cultural institutions and the substantial influence of the social media platform,the demands of visual communication keep increasing for promoting traditional cultural artifacts online.As an effective medium,posters serve to attract public attention and facilitate broader engagement with cultural artifacts.However,existing poster generation methods mainly rely on fixed templates and manual design,which limits their scalability and adaptability to the diverse visual and semantic features of the artifacts.Therefore,we propose CAPGen,an automated aesthetic Cultural Artifacts Poster Generation framework built on a Multimodal Large Language Model(MLLM)with integrated iterative optimization.During our research,we collaborated with designers to define principles of graphic design for cultural artifact posters,to guide the MLLM in generating layout parameters.Later,we generated these parameters into posters.Finally,we refined the posters using an MLLM integrated with a multi-round iterative optimization mechanism.Qualitative results show that CAPGen consistently outperforms baseline methods in both visual quality and aesthetic performance.Furthermore,ablation studies indicate that the prompt,iterative optimization mechanism,and design principles significantly enhance the effectiveness of poster generation.展开更多
Semantic segmentation for mixed scenes of aerial remote sensing and road traffic is one of the key technologies for visual perception of flying cars.The State-of-the-Art(SOTA)semantic segmentation methods have made re...Semantic segmentation for mixed scenes of aerial remote sensing and road traffic is one of the key technologies for visual perception of flying cars.The State-of-the-Art(SOTA)semantic segmentation methods have made remarkable achievements in both fine-grained segmentation and real-time performance.However,when faced with the huge differences in scale and semantic categories brought about by the mixed scenes of aerial remote sensing and road traffic,they still face great challenges and there is little related research.Addressing the above issue,this paper proposes a semantic segmentation model specifically for mixed datasets of aerial remote sensing and road traffic scenes.First,a novel decoding-recoding multi-scale feature iterative refinement structure is proposed,which utilizes the re-integration and continuous enhancement of multi-scale information to effectively deal with the huge scale differences between cross-domain scenes,while using a fully convolutional structure to ensure the lightweight and real-time requirements.Second,a welldesigned cross-window attention mechanism combined with a global information integration decoding block forms an enhanced global context perception,which can effectively capture the long-range dependencies and multi-scale global context information of different scenes,thereby achieving fine-grained semantic segmentation.The proposed method is tested on a large-scale mixed dataset of aerial remote sensing and road traffic scenes.The results confirm that it can effectively deal with the problem of large-scale differences in cross-domain scenes.Its segmentation accuracy surpasses that of the SOTA methods,which meets the real-time requirements.展开更多
The forward model of optical fiber strain induced by fractures,together with the associated model resolution matrix,is used to demonstrate the interpretability of fracture parameters once the fracture intersects the f...The forward model of optical fiber strain induced by fractures,together with the associated model resolution matrix,is used to demonstrate the interpretability of fracture parameters once the fracture intersects the fiber.A regularized inversion framework for fracture parameters is established to evaluate the influence of measured data quality on the accuracy of iterative regularized inversion.An interpretation approach for both fracture width and height is proposed,and the synthetic forward data with measurement error and field examples are employed to validate the accuracy of the simultaneous inversion of fracture width and height.The results indicate that,after the fracture contacts the fiber,the strain response is strongly sensitive only to the fracture parameters at the intersection location,whereas the interpretability of parameters at other locations remains limited.The iterative regularized inversion method effectively suppresses the impact of measurement error and exhibits high computational efficiency,showing clear advantages for inversion applications.When incorporating the first-order regularization with a Neumann boundary constraint on the tip width,the inverted fracture-width distribution becomes highly sensitive to fracture height;thus,combined with a bisection strategy,simultaneous inversion of fracture width and height can be achieved.Examination using the model resolution matrix,noisy synthetic data,and field data confirms that the iterative regularized inversion model for fracture width and height provides high interpretive accuracy and can be applied to the calculation and analysis of fracture width,fracture height,net pressure and other parameters.展开更多
Ductile iron pipes,a staple in global urban water supply systems,face a significant challenge in the form of corrosion,which threatens water quality and pipeline integrity.The deterioration mechanism of shrink-age def...Ductile iron pipes,a staple in global urban water supply systems,face a significant challenge in the form of corrosion,which threatens water quality and pipeline integrity.The deterioration mechanism of shrink-age defects on the passivation behavior of ductile iron in simulated concrete pore solution was investi-gated.The results indicated that shrinkage defects increase donor density and reduce the threshold value of chlorine concentration for rupture of ductile iron passion film(CTV)of ductile iron.Defects reduce CTV from 1-1.1 wt.%to 0.36-0.4 wt.%.Because the matrix/graphite around the defect has a higher Volta potential difference,the shrinkage defect preferentially corrodes and induces local corrosion of the sur-rounding matrix,while no significant corrosion was observed in the region away from the defect.High lattice distortion and Si segregation around the shrinkage defect improve the driving force of corrosion in thermodynamics.Furthermore,shrinkage defects elevate the content of Fe(Ⅲ)compounds in the passive film,without compromising its duplex structure.These defects accelerate the nucleation and growth of the passive film,but generate more cation interstitials.This variation of chemical composition of passive film compromises the film’s integrity and protective properties,attributable to a potential mechanism of micro-environmental acidification and the synergistic effects of shrinkage defect-graphite-matrix multiple micro-galvanic couples.展开更多
This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hype...This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller.展开更多
The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a block...The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises.展开更多
In this paper,a new technique is introduced to construct higher-order iterative methods for solving nonlinear systems.The order of convergence of some iterative methods can be improved by three at the cost of introduc...In this paper,a new technique is introduced to construct higher-order iterative methods for solving nonlinear systems.The order of convergence of some iterative methods can be improved by three at the cost of introducing only one additional evaluation of the function in each step.Furthermore,some new efficient methods with a higher-order of convergence are obtained by using only a single matrix inversion in each iteration.Analyses of convergence properties and computational efficiency of these new methods are made and testified by several numerical problems.By comparison,the new schemes are more efficient than the corresponding existing ones,particularly for large problem sizes.展开更多
BACKGROUND Thymic epithelial neoplasms are rare malignant neoplasms originating in the thymus gland.There have been case reports of patients with advanced thymomas treated with a methylprednisolone pulse or with gluco...BACKGROUND Thymic epithelial neoplasms are rare malignant neoplasms originating in the thymus gland.There have been case reports of patients with advanced thymomas treated with a methylprednisolone pulse or with glucocorticoid(GCs)shock be-fore surgery,followed by surgical treatment,all of whom achieved good results.The effect of GCs on thymomas is related mainly to the action on GC receptors in thymic lymphocytes and epithelial cells.GC receptor expression has been asso-ciated with a better prognosis in patients with thymomas,including those with surgically removed thymomas.CASE SUMMARY We report a case of a patient with thymoma who had a significant response to preoperative low-dose GC therapy.A mediastinal tumor was detected in the patient via computerized tomography upon admission.The tumor was initially suspected to be a thymic tumor,but lymphoma could not be ruled out.The tumor shrank significantly after low-dose(5 mg/day)GC therapy.Thoracoscopic thy-moma resection was performed after puncture pathology was confirmed.The patient recovered well after the operation and is currently performing well with no recurrence of the tumor.CONCLUSION This case highlights that low-dose GCs are effective in the treatment of thymomas,and we believe that GCs should be applied more frequently and studied more thoroughly in the treatment of thymomas.展开更多
To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of ...To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of concrete drying shrinkage tests were designed with three strength grade(C30,C40,and C50)as variables.By observing the drying-shrinkage deformation of the specimens over 360 days,the effects of fine-aggregate properties on the drying shrinkage properties of concrete of different strength grades were analyzed and a prediction model was developed.Compared with natural sand concrete,the development of drying shrinkage of manufactured-sand concrete exhibits the phenomenon of advancement.The apparent density of the fine-aggregate and the strength grade are the two main factors affecting the limit value of the drying shrinkage of concrete.With a reduction in the water absorption or apparent density of the fine-aggregate or the strength grade of concrete prepared using the same fine-aggregate,the prediction accuracy of the existing models decreases.According to the GL 2000 model,two coefficients-and-were introduced to propose a prediction model for the drying shrinkage of fine-aggregate concrete,which is applicable to different strength grades.展开更多
Obtaining large specific surface areas(SSA)for carbon xerogels poses a significant challenge due to the inevitable volume shrinkage of xerogel.Here,the Zn^(2+) coordination-catalyzed in-situ polymerization approach wa...Obtaining large specific surface areas(SSA)for carbon xerogels poses a significant challenge due to the inevitable volume shrinkage of xerogel.Here,the Zn^(2+) coordination-catalyzed in-situ polymerization approach was proposed to fabricate xerogels with a low shrinkage of 13.03% and a short preparation period of 24 h.In resorcinolformaldehyde(RF)polymerization,ZnCl_(2) could accelerate the reaction kinetics through the coordination of the Zn^(2+) and hydroxyl groups.The gel network with adjustable RF particles(46.5 nm-1.89μm)and narrow neck structures was constructed by changing ZnCl_(2) and ethanol contents,which could resist volume shrinkage during atmospheric drying without solvent exchange.The activated carbon xerogels(ACXs)with hierarchical structure were designed by one-step carbonization/activation due to the pore-forming of ZnCl_(2).The obtained ACXs showed a large SSA of 1689 m^(2)/g,multi-dyes adsorption capacity(methylene blue,Congo red,methyl orange,and Sudan Ⅲ were 625.90,359.46,320.69,and 453.92 mg/g,respectively),and reusability of 100%.The maximum monolayer MB adsorption capacity was 630.28 mg/g.This work presents an efficient strategy to design porous nanomaterials with low shrinkage and large SSA,which illustrates promising applications in separation,adsorption,and photoelectric catalysis.展开更多
基金National Natural Science Foundation of China under Grant 42304145Jiangxi Provincial Natural Science Foundation under Grant 20242BAB26051,20242BAB25191 and 20232BAB213077+1 种基金Foundation of National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing under Grant 2024QZ-TD-13Open Fund(FW0399-0002)of SINOPEC Key Laboratory of Geophysics。
文摘Data reconstruction is a crucial step in seismic data preprocessing.To improve reconstruction speed and save memory,the commonly used three-dimensional(3D)seismic data reconstruction method divides the missing data into a series of time slices and independently reconstructs each time slice.However,when this strategy is employed,the potential correlations between two adjacent time slices are ignored,which degrades reconstruction performance.Therefore,this study proposes the use of a two-dimensional curvelet transform and the fast iterative shrinkage thresholding algorithm for data reconstruction.Based on the significant overlapping characteristics between the curvelet coefficient support sets of two adjacent time slices,a weighted operator is constructed in the curvelet domain using the prior support set provided by the previous reconstructed time slice to delineate the main energy distribution range,eff ectively providing prior information for reconstructing adjacent slices.Consequently,the resulting weighted fast iterative shrinkage thresholding algorithm can be used to reconstruct 3D seismic data.The processing of synthetic and field data shows that the proposed method has higher reconstruction accuracy and faster computational speed than the conventional fast iterative shrinkage thresholding algorithm for handling missing 3D seismic data.
基金The National Natural Science Foundations of China (12202219)the Natural Science Foundations of Ningxia (2024AAC02009, 2023AAC05001)the Ningxia Youth Top Talents Training Project。
文摘The fast solution of linear equations has always been one of the hot spots in scientific computing.A kind of the diagonal matrix splitting iteration methods are provided,which is different from the classical matrix splitting methods.Taking the decomposition of the diagonal elements for coefficient matrix as the key point,some new preconditioners are constructed.Taking the tri-diagonal coefficient matrix as an example,the convergence domains and optimal relaxation factor of the new method are analyzed theoretically.The presented new iteration methods are applied to solve linear algebraic equations,even 2D and 3D diffusion problems with the fully implicit discretization.The results of numerical experiments are matched with the theoretical analysis,and show that the iteration numbers are reduced greatly.The superiorities of presented iteration methods exceed some classical iteration methods dramatically.
基金Supported in part by Natural Science Foundation of Guangxi(2023GXNSFAA026246)in part by the Central Government's Guide to Local Science and Technology Development Fund(GuikeZY23055044)in part by the National Natural Science Foundation of China(62363003)。
文摘In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method.
文摘Purpose-The utilization of alkali-free accelerators,primarily based on aluminum sulfate,in shotcrete often leads to significant shrinkage and cracking,jeopardizing long-term durability.This study aims to mitigate this issue by investigating the efficacy of silica fume(SF)and fly ash(FA),individually and combined,in controlling the shrinkage deformation of shotcrete.Design/methodology/approach-Shotcrete mixtures were prepared with cement partially replaced by SF,FA,or their combination(SF-FA).Aluminum sulfate was used as an accelerator.The shrinkage behavior under sealed and dry conditions was monitored.The underlying mechanisms were elucidated through hardened airvoid analysis,mercury intrusion porosimetry(MIP),and internal humidity tracking.Findings-Contrary to some previous studies,both individual and combined incorporation of mineral admixtures reduced the 28-day shrinkage.The SF-FA composite exhibited the most substantial reduction(23.72%sealed,17.76%dry),followed by SF alone(18.11%sealed)and FA alone(11.35%sealed).Mechanism analysis revealed that the admixtures refined the pore structure,reduced the volume of harmful pores,and,crucially,optimized the air-void system by increasing the population of fine bubbles.This created an internal buffering effect that alleviates capillary stress.The synergistic effect in the SF-FA group is attributed to complementary pore-filling at dual scales.Originality/value-This work demonstrates that,within an aluminum sulfate-accelerated shotcrete system,silica fume can effectively reduce shrinkage when its pore-refining effect is counterbalanced by a welloptimized micro-bubble network.It provides the first comprehensive evidence of the synergistic shrinkagereducing mechanism of SF and FA in such systems,offering a practical strategy for mix design optimization to enhance the volume stability of shotcrete.
基金Funded by the National Key Research and Development Program of China(No.2020YFC1909905)the Science and Technology Research and Development Plan of China National Railway Group Co.,Ltd.(No.L2022G009)the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘This study aimed to investigate the influence of recycled sand(RS)content and water-binder ratio on the long term performance of recycled sand concrete(RSC).A 220 days drying shrinkage and creep test of RSC was conducted,and the microhardness of ITZ were analyzed to explain the differences in performance.The experimental results indicate that,when RS content is 50%,the drying shrinkage and creep strain of RSC is the smallest.This is attributed to the highest microhardness in the ITZ when the RS content is 50%.When the RS content is 100%,the shrinkage and creep strains increase due to the high water absorption of RS,which leads to the evaporation of additional water and the deterioration of the ITZ.As the water-binder ratio increases,the drying shrinkage and creep strain of RSC with different RS content increases.According to the EC2 specification and the CEB-FIP specification,the drying shrinkage and creep prediction models for RSC have been established.
基金financially supported by the National Natural Science Foundation of China(No.52273104)。
文摘Mini light-emitting diodes(Mini-LEDs)show great application potential in high-end displays owing to their superior pixel density,brightness,responsiveness,and efficiency.However,current packaging materials for Mini-LEDs are predominantly thermally cured,which is energy-and time-consuming and can adversely affect electronic components.In this study,a novel UV-curable silicone resin containing phenyl,disulfide,and acryloyl groups(SPASR)is developed from commercially available siloxanes.The resin exhibits a refractive index(n_(d))higher than 1.5,and it can be cured within 30 s under UV irradiation.After curing,it exhibits an optical transparency exceeding 92%,a lap adhesion strength of up to1.84 MPa,and good thermostability(T_(5%)>265℃).Notably,the volume shrinkage is less than 4.83%,attributed to the release of photopolymerization stress via UV-induced disulfide metathesis during UV curing.Mini-LEDs encapsulated with this resin show luminescence properties comparable to those of conventional thermally-cured sealants,and show excellent sealability wihtout visible penetration after being immersed in red ink for 12 h.Consequently,these excellent properties make the SPASR resin an ideal candidate for microelectronic encapsulation,offering a more reliable and efficient solution for the electronics industry.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3701000)the National Natural Science Foundation of China(Nos.52471118,52101125,U2037601,and U21A2048)Young Elite Scientists Sponsorship Program by CAST,China(No.2022QNRC001)。
文摘The dependence of shrinkage porosities on microstructure characteristics of Mg−12Al alloy was investigated.The distribution,morphology,size,and number density of shrinkage porosities were analyzed under different cooling rates.The relationship between shrinkage porosities and microstructure characteristics was discussed in terms of temperature conditions,feeding channel characteristics,and feeding capacity.Further,the feeding behavior of the residual liquid phase in the solid skeleton was quantified by introducing permeability.Results show a strong correlation between the solid microstructure skeleton and shrinkage porosity characteristics.An increase in permeability corresponds to a declining number density of shrinkage porosities.This study aims to provide a more complete understanding how to reduce shrinkage porosities by controlling microstructure characteristics.
基金supported by the National Natural Science Foundation of China(No.12575189)。
文摘Deep learning methods have achieved significant progress in solving partial differential equations.However,when applied to the widely used anisotropic scattering neutron transport equations in reactor engineering,these encounter significant challenges.To address this issue,this study introduces a multi-antiderivative transformation alternating iterative deep learning method(M-AIM).This method transforms the integral terms of the scattering and fission sources in the transport equation into multiple antiderivative functions corresponding to the integrand,converts the differential-integral form of the transport equation into an exact differential equation,and establishes the necessary constraints for a unique solution.The M-AIM uses multiple deep neural networks to map the unknown angular flux density of transport equations and represents various forms of antiderivative functions.It constructs the corresponding weighted loss functions.By alternating iterative training with deep learning methods applied to these neural networks,the loss is reduced gradually.When the loss decreases to a preset minimum,the neural network approaches a numerical solution for both angular flux density and antiderivative functions.This paper presents a numerical verification of geometries such as flat plates and spheres.It verifies the validity of the theoretical framework and associated methods.The study contributes to the development of novel technical approaches for applying deep learning to solve anisotropic scattering neutron transport equations in reactor engineering.
基金funded by the Wuxi Young Scientific and Technological Talent Support Initiative,project number:TJXD-2024-203the Natural Science Foundation of the Jiangsu Higher Education Institutions of China,grant number:24KJB470027.
文摘Iterative Learning Control(ILC)provides an effective framework for optimizing repetitive tasks,making it particularly suitable for high-precision applications in both precision manufacturing and intelligent transportation systems(ITS).This paper presents a systematic review of ILC's developmental progress,current methodologies,and practical implementations across these two critical domains.The review first analyzes the key technical challenges encountered when integrating ILC into precision manufacturing workflows.Through case studies,it evaluates demonstrated improvements in positioning accuracy,surface finish quality,and production throughput.Furthermore,the study examines ILC’s applications in ITS,with particular focus on vehicular motion control applications including autonomous vehicle trajectory tracking,platoon coordination,and traffic signal timing optimization,where its data-driven characteristics enhance adaptability to dynamic environments.Finally,the paper proposes targeted future research directions that are essential for fully realizing ILC’s potential in advancing these interconnected yet distinct fields.
文摘The iterative continuation task(ICT)requires English as a foreign language(EFL)learners to read a segment and write a continuation that aligns with the preceding segment of an English novel with successive turns,offering exposure to diverse grammatical structures and opportunities for contextualized usage.Given the importance of integrating technology into second language(L2)writing and the critical role that grammar plays in L2 writing development,automated written corrective feedback provided by Grammarly has gained significant attention.This study investigates the impact of Grammarly on grammar learning strategies,grammar grit,and grammar competence among EFL college students engaged in ICT.This study employed a mixed-methods sequential exploratory design;56 participants were divided into an experimental group(n=28),receiving Grammarly feedback for ICT,and a control group(n=28),completing ICT without Grammarly feedback.Quantitative results revealed that both groups showed improvements in L2 grammar learning strategies,grit and competence.For the experimental group,significant differences were observed across all variables of L2 grammar learning strategies,grit,and competence between pre-and post-tests.For the control group,significant differences were only observed in the affective dimension of grammar learning strategies,Consistency of Interest(COI)of grammar grit,and grammar competence.However,the control group presented a significantly higher improvement in grammar competence.Qualitative analysis showed both positive and negative perceptions of Grammarly.The pedagogical implications of integrating Grammarly and ICT for L2 grammar development are discussed.
基金supported by the National Key Research and Development Program of China(2023YFF0906502)the Postgraduate Research and Innovation Project of Hunan Province under Grant(CX20240473).
文摘Due to the digital transformation tendency among cultural institutions and the substantial influence of the social media platform,the demands of visual communication keep increasing for promoting traditional cultural artifacts online.As an effective medium,posters serve to attract public attention and facilitate broader engagement with cultural artifacts.However,existing poster generation methods mainly rely on fixed templates and manual design,which limits their scalability and adaptability to the diverse visual and semantic features of the artifacts.Therefore,we propose CAPGen,an automated aesthetic Cultural Artifacts Poster Generation framework built on a Multimodal Large Language Model(MLLM)with integrated iterative optimization.During our research,we collaborated with designers to define principles of graphic design for cultural artifact posters,to guide the MLLM in generating layout parameters.Later,we generated these parameters into posters.Finally,we refined the posters using an MLLM integrated with a multi-round iterative optimization mechanism.Qualitative results show that CAPGen consistently outperforms baseline methods in both visual quality and aesthetic performance.Furthermore,ablation studies indicate that the prompt,iterative optimization mechanism,and design principles significantly enhance the effectiveness of poster generation.
基金supported by the National Key Research and Development of China(No.2022YFB2503400).
文摘Semantic segmentation for mixed scenes of aerial remote sensing and road traffic is one of the key technologies for visual perception of flying cars.The State-of-the-Art(SOTA)semantic segmentation methods have made remarkable achievements in both fine-grained segmentation and real-time performance.However,when faced with the huge differences in scale and semantic categories brought about by the mixed scenes of aerial remote sensing and road traffic,they still face great challenges and there is little related research.Addressing the above issue,this paper proposes a semantic segmentation model specifically for mixed datasets of aerial remote sensing and road traffic scenes.First,a novel decoding-recoding multi-scale feature iterative refinement structure is proposed,which utilizes the re-integration and continuous enhancement of multi-scale information to effectively deal with the huge scale differences between cross-domain scenes,while using a fully convolutional structure to ensure the lightweight and real-time requirements.Second,a welldesigned cross-window attention mechanism combined with a global information integration decoding block forms an enhanced global context perception,which can effectively capture the long-range dependencies and multi-scale global context information of different scenes,thereby achieving fine-grained semantic segmentation.The proposed method is tested on a large-scale mixed dataset of aerial remote sensing and road traffic scenes.The results confirm that it can effectively deal with the problem of large-scale differences in cross-domain scenes.Its segmentation accuracy surpasses that of the SOTA methods,which meets the real-time requirements.
基金Supported by the Ministry of Education U40 Program(ZYGXONJSKYCXNLZCXM-E19)National Natural Science Foundation of China(52574078)。
文摘The forward model of optical fiber strain induced by fractures,together with the associated model resolution matrix,is used to demonstrate the interpretability of fracture parameters once the fracture intersects the fiber.A regularized inversion framework for fracture parameters is established to evaluate the influence of measured data quality on the accuracy of iterative regularized inversion.An interpretation approach for both fracture width and height is proposed,and the synthetic forward data with measurement error and field examples are employed to validate the accuracy of the simultaneous inversion of fracture width and height.The results indicate that,after the fracture contacts the fiber,the strain response is strongly sensitive only to the fracture parameters at the intersection location,whereas the interpretability of parameters at other locations remains limited.The iterative regularized inversion method effectively suppresses the impact of measurement error and exhibits high computational efficiency,showing clear advantages for inversion applications.When incorporating the first-order regularization with a Neumann boundary constraint on the tip width,the inverted fracture-width distribution becomes highly sensitive to fracture height;thus,combined with a bisection strategy,simultaneous inversion of fracture width and height can be achieved.Examination using the model resolution matrix,noisy synthetic data,and field data confirms that the iterative regularized inversion model for fracture width and height provides high interpretive accuracy and can be applied to the calculation and analysis of fracture width,fracture height,net pressure and other parameters.
基金financially supported by the National Natural Science Foundation of China(Nos.52104319 and 52374323).
文摘Ductile iron pipes,a staple in global urban water supply systems,face a significant challenge in the form of corrosion,which threatens water quality and pipeline integrity.The deterioration mechanism of shrink-age defects on the passivation behavior of ductile iron in simulated concrete pore solution was investi-gated.The results indicated that shrinkage defects increase donor density and reduce the threshold value of chlorine concentration for rupture of ductile iron passion film(CTV)of ductile iron.Defects reduce CTV from 1-1.1 wt.%to 0.36-0.4 wt.%.Because the matrix/graphite around the defect has a higher Volta potential difference,the shrinkage defect preferentially corrodes and induces local corrosion of the sur-rounding matrix,while no significant corrosion was observed in the region away from the defect.High lattice distortion and Si segregation around the shrinkage defect improve the driving force of corrosion in thermodynamics.Furthermore,shrinkage defects elevate the content of Fe(Ⅲ)compounds in the passive film,without compromising its duplex structure.These defects accelerate the nucleation and growth of the passive film,but generate more cation interstitials.This variation of chemical composition of passive film compromises the film’s integrity and protective properties,attributable to a potential mechanism of micro-environmental acidification and the synergistic effects of shrinkage defect-graphite-matrix multiple micro-galvanic couples.
基金supported by the National Natural Science Foundation of China(12072090).
文摘This work proposes the application of an iterative learning model predictive control(ILMPC)approach based on an adaptive fault observer(FOBILMPC)for fault-tolerant control and trajectory tracking in air-breathing hypersonic vehicles.In order to increase the control amount,this online control legislation makes use of model predictive control(MPC)that is based on the concept of iterative learning control(ILC).By using offline data to decrease the linearized model’s faults,the strategy may effectively increase the robustness of the control system and guarantee that disturbances can be suppressed.An adaptive fault observer is created based on the suggested ILMPC approach in order to enhance overall fault tolerance by estimating and compensating for actuator disturbance and fault degree.During the derivation process,a linearized model of longitudinal dynamics is established.The suggested ILMPC approach is likely to be used in the design of hypersonic vehicle control systems since numerical simulations have demonstrated that it can decrease tracking error and speed up convergence when compared to the offline controller.
基金supported in part by the National Natural Science Foundation of China(62273310)the Natural Science Foundation of Zhejiang Province of China(LY22F030006,LZ24F030009)
文摘The increased demand for personalized customization calls for new production modes to enhance collaborations among a wide range of manufacturing practitioners who unnecessarily trust each other.In this article,a blockchain-enabled manufacturing collaboration framework is proposed,with a focus on the production capacity matching problem for blockchainbased peer-to-peer(P2P)collaboration.First,a digital model of production capacity description is built for trustworthy and transparent sharing over the blockchain.Second,an optimization problem is formulated for P2P production capacity matching with objectives to maximize both social welfare and individual benefits of all participants.Third,a feasible solution based on an iterative double auction mechanism is designed to determine the optimal price and quantity for production capacity matching with a lack of personal information.It facilitates automation of the matching process while protecting users'privacy via blockchainbased smart contracts.Finally,simulation results from the Hyperledger Fabric-based prototype show that the proposed approach increases social welfare by 1.4%compared to the Bayesian game-based approach,makes all participants profitable,and achieves 90%fairness of enterprises.
基金Supported by the National Natural Science Foundation of China(12061048)NSF of Jiangxi Province(20232BAB201026,20232BAB201018)。
文摘In this paper,a new technique is introduced to construct higher-order iterative methods for solving nonlinear systems.The order of convergence of some iterative methods can be improved by three at the cost of introducing only one additional evaluation of the function in each step.Furthermore,some new efficient methods with a higher-order of convergence are obtained by using only a single matrix inversion in each iteration.Analyses of convergence properties and computational efficiency of these new methods are made and testified by several numerical problems.By comparison,the new schemes are more efficient than the corresponding existing ones,particularly for large problem sizes.
文摘BACKGROUND Thymic epithelial neoplasms are rare malignant neoplasms originating in the thymus gland.There have been case reports of patients with advanced thymomas treated with a methylprednisolone pulse or with glucocorticoid(GCs)shock be-fore surgery,followed by surgical treatment,all of whom achieved good results.The effect of GCs on thymomas is related mainly to the action on GC receptors in thymic lymphocytes and epithelial cells.GC receptor expression has been asso-ciated with a better prognosis in patients with thymomas,including those with surgically removed thymomas.CASE SUMMARY We report a case of a patient with thymoma who had a significant response to preoperative low-dose GC therapy.A mediastinal tumor was detected in the patient via computerized tomography upon admission.The tumor was initially suspected to be a thymic tumor,but lymphoma could not be ruled out.The tumor shrank significantly after low-dose(5 mg/day)GC therapy.Thoracoscopic thy-moma resection was performed after puncture pathology was confirmed.The patient recovered well after the operation and is currently performing well with no recurrence of the tumor.CONCLUSION This case highlights that low-dose GCs are effective in the treatment of thymomas,and we believe that GCs should be applied more frequently and studied more thoroughly in the treatment of thymomas.
基金Funded by the National Natural Science Foundation of China project(Nos.52108219 and U21A20150)the Lanzhou University of Technology Hongliu Outstanding Young Talent Program,China(No.04-062407)the Research on Quality Control Technology of High-performance Concrete Prepared by Manufactured Sand(No.2020Y21)。
文摘To study the effects of fine-aggregates on the drying-shrinkage properties of concrete,two types of manufactured-sand and one type of natural sand(excluding<75μm particles)were selected for tests,and nine sets of concrete drying shrinkage tests were designed with three strength grade(C30,C40,and C50)as variables.By observing the drying-shrinkage deformation of the specimens over 360 days,the effects of fine-aggregate properties on the drying shrinkage properties of concrete of different strength grades were analyzed and a prediction model was developed.Compared with natural sand concrete,the development of drying shrinkage of manufactured-sand concrete exhibits the phenomenon of advancement.The apparent density of the fine-aggregate and the strength grade are the two main factors affecting the limit value of the drying shrinkage of concrete.With a reduction in the water absorption or apparent density of the fine-aggregate or the strength grade of concrete prepared using the same fine-aggregate,the prediction accuracy of the existing models decreases.According to the GL 2000 model,two coefficients-and-were introduced to propose a prediction model for the drying shrinkage of fine-aggregate concrete,which is applicable to different strength grades.
基金supported by the National Key Research and Development Program of China(No.2023YFB3711501)Shanghai Industrial Collaborative Innovation Leading Group Office(No.XTCX-KJ-2023-53)+3 种基金the Fundamental Research Funds for the Central Universities(No.23D110609)the Open Research Fund of Songshan Lake Materials Laboratory(No.2022SLABFN09)the Foundation of State Key Laboratory of Biobased Material and Green Papermaking,Qilu University of Technology,Shandong Academy of Sciences(No.GZKF202231)the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DH-D-2022012).
文摘Obtaining large specific surface areas(SSA)for carbon xerogels poses a significant challenge due to the inevitable volume shrinkage of xerogel.Here,the Zn^(2+) coordination-catalyzed in-situ polymerization approach was proposed to fabricate xerogels with a low shrinkage of 13.03% and a short preparation period of 24 h.In resorcinolformaldehyde(RF)polymerization,ZnCl_(2) could accelerate the reaction kinetics through the coordination of the Zn^(2+) and hydroxyl groups.The gel network with adjustable RF particles(46.5 nm-1.89μm)and narrow neck structures was constructed by changing ZnCl_(2) and ethanol contents,which could resist volume shrinkage during atmospheric drying without solvent exchange.The activated carbon xerogels(ACXs)with hierarchical structure were designed by one-step carbonization/activation due to the pore-forming of ZnCl_(2).The obtained ACXs showed a large SSA of 1689 m^(2)/g,multi-dyes adsorption capacity(methylene blue,Congo red,methyl orange,and Sudan Ⅲ were 625.90,359.46,320.69,and 453.92 mg/g,respectively),and reusability of 100%.The maximum monolayer MB adsorption capacity was 630.28 mg/g.This work presents an efficient strategy to design porous nanomaterials with low shrinkage and large SSA,which illustrates promising applications in separation,adsorption,and photoelectric catalysis.
