Investigation of the Film Formation in Dynamic Air Spray Painting

To accurately predict the film thickness distribution during dynamic spraying performed with air guns and support accordingly the development of intelligent spray painting,the spray problem was analyzed numerically.In particular,the Eulerian-Eulerian approach was employed to calculate the paint atomization and film deposition process.Different spray heights,spray angles,spray gun movement speeds,spray trajectory curvature radii,and air pressure values were considered.Numerical simulation results indicate that the angle of spray painting significantly affects the velocity of droplets near the spray surface.With an increase in the spraying angle,spraying height and spray gun movement speed,the maximum film thickness decreases to varying degrees,and the uniformity of the film thickness also continuously worsens.When the spray gun moves along an arc trajectory,at smaller arc radii,the film thickness on the inside of the arc is slightly greater than that on the outside,but the impact on the maximum film thickness is minimal.Increasing air pressure expands the coating coverage area,results in finer atomization of paint droplets,and leads to a thinner and a more uniform paint film.However,if the pressure is too high,it can cause paint splattering.Using the orthogonal experimental method,multiple sets of simulation calculations were conducted,and the combined effects of spraying height,spray angle,and spray gun movement speed on the film thickness distribution were comprehensively analyzed to determine optimal configurations.Finally,the reliability of the numerical simulations was validated through dynamic spray painting experiments.

Improved Scatter Search Algorithm for Multi-skilled Personnel Scheduling of Ship Block Painting

This paper focuses on the optimization method for multi-skilled painting personnel scheduling.The budget working time analysis is carried out considering the influence of operating area,difficulty of spraying area,multi-skilled workers,and worker’s efficiency,then a mathematical model is established to minimize the completion time. The constraints of task priority,paint preparation,pump management,and neighbor avoidance in the ship block painting production are considered. Based on this model,an improved scatter search(ISS)algorithm is designed,and the hybrid approximate dynamic programming(ADP)algorithm is used to improve search efficiency. In addition,the two solution combination methods of path-relinking and task sequence combination are used to enhance the search breadth and depth. The numerical experimental results show that ISS has a significant advantage in solving efficiency compared with the solver in small scale instances;Compared with the scatter search algorithm and genetic algorithm,ISS can stably improve the solution quality. Verified by the production example,ISS effectively shortens the total completion time of the production,which is suitable for scheduling problems in the actual painting production of the shipyard.

The Study of “Imitation” Aesthetics in Ancient Painting Theory-Taking the Chinese and Western Sources as an Example

The theory of“imitation”in painting occupies a leading position in western art,which originated from the theory of“imitation”in ancient Greece,and has become one of the art theories affecting the world through the continuous development of later generations.Through the exploration of the source of“imitation”in China and the West,there are some comments on the meaning of“imitation”in Chinese classical painting theory,such as“transfer model writing”and“image form”,which is obvious differences from the west.Traditional Chinese painting is a combination of careful observation of natural things and subjective emotions to express their own aesthetic feelings,and ultimately form a vivid artistic conception.Modern imitation is borrowed from Western imitation.In fact,imitation in traditional painting has its own meaning,which contains Chinese aesthetic thought.“Imitation”aesthetics is unique in traditional Chinese painting and is the most important form of painting art.

Analysis of Color and Artistic Conception in Painting Art

The charm of painting,as a bright pearl in the treasure house of culture,lies in its visual language constructed through colors and lines,which conveys the artist’s unique perception of life and profound emotions.Color,as the most intuitive and expressive language in painting,is not only a simple reproduction of material colors but also a projection of the artist’s inner world.Artistic conception,as a core concept in traditional Chinese painting theory,refers to the emotional atmosphere and spiritual mood embedded in paintings.The purpose of this paper is to discuss the interaction between color and mood in painting art,to analyze the techniques of using color in different painting styles and their influence on the creation of mood,and to provide new perspectives and methods for the creation of paintings.

Exploration of the Expression of Color Emotion in Oil Painting Sketch Creation

This paper deeply analyzes the expression of color emotion in oil painting sketch creation.Starting with the three basic attributes of color theory(hue,lightness,and purity),this paper discusses its emotional symbolic significance and the relationship between contrast and harmony.By interpreting the works of artists such as Van Gogh’s Sunflower,Monet’s Rouen Cathedral,and Cézanne’s Mont Sainte-Victoire,this paper shows the unique charm of different colors in conveying emotions,creating atmosphere,and expressing themes.At the same time,it is expounded that in the creation of an oil painting sketch,the effective expression of color emotion can be realized by observing nature,using subjective colors,and reasonable composition and layout of colors,so as to enhance the artistic value of the works.

Analysis of Viewing Paintings from the Perspective of Iconography

Distinguished from purely formalistic research methods,iconography pursues the interpretation of the hidden historical and humanistic connotations behind artworks,and is a discipline that combines visual text and content analysis methods.Combining the three stages of iconography proposed by Panofsky,the paper studies Shizeng Chen’s Viewing Paintings from the perspective of iconography,summarizing the formation and change of the images and contents of the artworks in the cultural system and civilization at that time,as well as their implied ideology,and analyzing the hidden spirit of the times and the historical significance behind them,so as to expound their iconographic significance.Through an in-depth discussion at three levels:pre-pictorial iconographic description,iconographic analysis,and iconographic interpretation,the facts and surface contents reproduced in the images,the traditional level of literary,artistic,and cultural knowledge,as well as the interpretation of the potential meanings are revealed.

Color Expression and Mood Creation in Imagery Oil Painting

Oil painting is a traditional Western painting form.With the introduction of China and the influence of China’s traditional painting and aesthetics,the painting style became more distinctive,expanding a new development direction of oil painting,and thus imagery oil painting came into being.Color,as the most important element in imagery oil painting,mainly plays the role of mood creation and emotional expression.Many creators are good at injecting their thoughts and emotions into the paintings through color matching,so as to enhance the artistic expression of the paintings.This paper analyzes the color expression characteristics of imagery oil painting and explores the color expression techniques in imagery oil painting and mood creation of imagery oil painting from several aspects.

Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei

Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted.

Chinese Sources for AfterWards:From Premodern Poetry,Paintings,and Medical Texts to Modern Novels,Film,and Documentaries

This paper focuses on Chinese sources suggested for a narrative medicine(NM)program,called AfterWards.Dr Lauren Small established AfterWards in 2014 and has been coordinating it since out of the Pediatrics Department at Johns Hopkins Medicine.In early 2019,she started giving a series of lectures and workshops about AfterWards to Chinese medical educators and clinicians in Beijing and Shanghai.She created an AfterWards Facilitator’s Guide based on Western-language sources for workshop participants.She also started to organize with Jiang Yuhong(Peking Union Medical College)a workshop for Chinese colleagues to be held at Johns Hopkins Medicine in October 2019.They invited the author to participate.The idea was hatched then to develop Chinese source materials following the AfterWards structure for an updated Facilitator’s Guide that Dr Small had initially written.A typical one-hour AfterWards session consists of a specific five-part structure:a literary text or artwork,an associated theme,discussion topics,a writing exercise,and shared reflection.While the content of the program always changes from session to session,the basic structure remains the same.This paper summarizes the types of Chinese sources and their related narrative-medicine themes that were originally selected for inclusion in the updated AfterWards Facilitator’s Guide intended for Chinese colleagues.These sources about coping with sick family members,aging,and illness ranged from the textual(classical Chinese poems on aging and diagnostic forms for training students)and visual(premodern Chinese paintings and murals of medical encounters)to the fictive(novels)and performative(contemporary Asian-American film in English and Chinese-language film and documentaries).

APST-Flow: A Reversible Network-Based Artistic Painting Style Transfer Method

In recent years,deep generative models have been successfully applied to perform artistic painting style transfer(APST).The difficulties might lie in the loss of reconstructing spatial details and the inefficiency of model convergence caused by the irreversible en-decoder methodology of the existing models.Aiming to this,this paper proposes a Flow-based architecture with both the en-decoder sharing a reversible network configuration.The proposed APST-Flow can efficiently reduce model uncertainty via a compact analysis-synthesis methodology,thereby the generalization performance and the convergence stability are improved.For the generator,a Flow-based network using Wavelet additive coupling(WAC)layers is implemented to extract multi-scale content features.Also,a style checker is used to enhance the global style consistency by minimizing the error between the reconstructed and the input images.To enhance the generated salient details,a loss of adaptive stroke edge is applied in both the global and local model training.The experimental results show that the proposed method improves PSNR by 5%,SSIM by 6.2%,and decreases Style Error by 29.4%over the existing models on the ChipPhi set.The competitive results verify that APST-Flow achieves high-quality generation with less content deviation and enhanced generalization,thereby can be further applied to more APST scenes.

Prescribed Performance Tracking Control of Time-Delay Nonlinear Systems With Output Constraints

The problem of prescribed performance tracking control for unknown time-delay nonlinear systems subject to output constraints is dealt with in this paper. In contrast with related works, only the most fundamental requirements, i.e., boundedness and the local Lipschitz condition, are assumed for the allowable time delays. Moreover, we focus on the case where the reference is unknown beforehand, which renders the standard prescribed performance control designs under output constraints infeasible. To conquer these challenges, a novel robust prescribed performance control approach is put forward in this paper.Herein, a reverse tuning function is skillfully constructed and automatically generates a performance envelop for the tracking error. In addition, a unified performance analysis framework based on proof by contradiction and the barrier function is established to reveal the inherent robustness of the control system against the time delays. It turns out that the system output tracks the reference with a preassigned settling time and good accuracy,without constraint violations. A comparative simulation on a two-stage chemical reactor is carried out to illustrate the above theoretical findings.

Design of low-alloying and high-performance solid solution-strengthened copper alloys with element substitution for sustainable development

Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.

Optimizing support performances of bolt reaming and anchoring in a coal drift

In current practice of bolt reaming and anchoring of roadways in soft coal and rock mass,resin cartridges bend easily under the strong pushing and stirring of bolts,and the resin accumulates in the bolt-reamed area and does not participate in the stirring.As a result,bolts encounter high drilling resistance and cannot reach the bottom of drillholes.The effective anchorage length is far less than the actual anchorage length.Bolts are not centered,and the shear is misaligned at the joint surface in the reaming area,which leads to cracking of the whole anchoring solid and large shear deformation of bolts.This study systematically analyzes the characteristics of roadway bolt reaming and anchoring.The influences of resin stirring force,bolt pull-out force,and reamingeanchoring solid strength on reamingeanchoring performance were analyzed theoretically.The main purpose is to develop a device that enhances reaming and anchoring.The mechanism through which the device strengthens the reamingeanchoring solid was analyzed theoretically.Numerical simulation and experiments were carried out to verify the improved performance of the small-pore reaming and anchoring using the proposed technology.The results showed that the stirring migration rate of the resin cartridge is greatly improved by adding the device to bolts.The reaction rate of the anchoring mixture,stirring pressure,pull-out force of the reaming and anchoring system,bolt concentricity,and shear and compressive strengths of the anchoring solid are also enhanced in the reaming area.This ensures that the resin cartridge in the reaming area is completely stirred,which greatly improves the shear resistance of the reamingeanchoring solid.Meanwhile,the drilling performance,torsional force,and stirring efficiency of bolts are maximized and prevail over those of conventional bolts.

Health diagnosis of ultrahigh arch dam performance using heterogeneous spatial panel vector model

Currently,more than ten ultrahigh arch dams have been constructed or are being constructed in China.Safety control is essential to long-term operation of these dams.This study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams.A comprehensive analysis was conducted,focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in China.Subsequently,the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored,including periodicity,convergence,and time-effect characteristics.These findings revealed the governing mechanism of main factors.Furthermore,a heterogeneous spatial panel vector model was developed,considering both common factors and specific factors affecting the safety and performance of arch dams.This model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions,introducing a specific effect quantity to characterize local deformation differences.Ultimately,the proposed model was applied to the Xiaowan arch dam,accurately quantifying the spatiotemporal heterogeneity of dam performance.Additionally,the spatiotemporal distri-bution characteristics of environmental load effects on different parts of the dam were reasonably interpreted.Validation of the model prediction enhances its credibility,leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan dam.The findings not only enhance the predictive ability and timely control of ultrahigh arch dams'performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures.

Finite-time Prescribed Performance Time-Varying Formation Control for Second-Order Multi-Agent Systems With Non-Strict Feedback Based on a Neural Network Observer

This paper studies the problem of time-varying formation control with finite-time prescribed performance for nonstrict feedback second-order multi-agent systems with unmeasured states and unknown nonlinearities.To eliminate nonlinearities,neural networks are applied to approximate the inherent dynamics of the system.In addition,due to the limitations of the actual working conditions,each follower agent can only obtain the locally measurable partial state information of the leader agent.To address this problem,a neural network state observer based on the leader state information is designed.Then,a finite-time prescribed performance adaptive output feedback control strategy is proposed by restricting the sliding mode surface to a prescribed region,which ensures that the closed-loop system has practical finite-time stability and that formation errors of the multi-agent systems converge to the prescribed performance bound in finite time.Finally,a numerical simulation is provided to demonstrate the practicality and effectiveness of the developed algorithm.

Role of End-ring Configuration in Shaping IE4 Induction Motor Performance

The performance characteristics,particularly the starting performance of direct line-fed induction motors,which are mainly influenced by the design of the rotor,are crucial considerations for end-users.It is quite a challenging issue for motor manufacturers to enhance the starting performance of existing mass-produced motors with minimal modifications and expenses.In this paper,a simple and cost-effective method to improve the starting performance of a commercial squirrel-cage induction motor(SCIM)is proposed.The influence of geometric parameters of the end-ring on the performance characteristics,including starting(locked rotor)torque,pull-up and break down torque,starting current,rotor electric parameters,current density,power losses,and efficiency have been comprehensively investigated.It has been revealed that among the other end-ring design parameters,the ring thickness has a significant effect on the performance characteristics.An optimal end-ring thickness is determined,and its performance characteristics have been compared to those of its initial counterpart.Numeric and parametric analyses have been conducted using a 2D time-stepping finite element method(FEM).The FEM results were validated using experimental measurements obtained from an 11 kW SCIM prototype.

Unveiling Organic Electrode Materials in Aqueous Zinc-Ion Batteries:From Structural Design to Electrochemical Performance

Aqueous zinc-ion batteries(AZIBs)are one of the most compelling alternatives of lithium-ion batteries due to their inherent safety and economics viability.In response to the growing demand for green and sustainable energy storage solutions,organic electrodes with the scalability from inexpensive starting materials and potential for biodegradation after use have become a prominent choice for AZIBs.Despite gratifying progresses of organic molecules with electrochemical performance in AZIBs,the research is still in infancy and hampered by certain issues due to the underlying complex electrochemistry.Strategies for designing organic electrode materials for AZIBs with high specific capacity and long cycling life are discussed in detail in this review.Specifically,we put emphasis on the unique electrochemistry of different redox-active structures to provide in-depth understanding of their working mechanisms.In addition,we highlight the importance of molecular size/dimension regarding their profound impact on electrochemical performances.Finally,challenges and perspectives are discussed from the developing point of view for future AZIBs.We hope to provide a valuable evaluation on organic electrode materials for AZIBs in our context and give inspiration for the rational design of high-performance AZIBs.

Assessment of Dependent Performance Shaping Factors in SPAR-H Based on Pearson Correlation Coefficient

With the improvement of equipment reliability,human factors have become the most uncertain part in the system.The standardized Plant Analysis of Risk-Human Reliability Analysis(SPAR-H)method is a reliable method in the field of human reliability analysis(HRA)to evaluate human reliability and assess risk in large complex systems.However,the classical SPAR-H method does not consider the dependencies among performance shaping factors(PSFs),whichmay cause overestimation or underestimation of the risk of the actual situation.To address this issue,this paper proposes a new method to deal with the dependencies among PSFs in SPAR-H based on the Pearson correlation coefficient.First,the dependence between every two PSFs is measured by the Pearson correlation coefficient.Second,the weights of the PSFs are obtained by considering the total dependence degree.Finally,PSFs’multipliers are modified based on the weights of corresponding PSFs,and then used in the calculating of human error probability(HEP).A case study is used to illustrate the procedure and effectiveness of the proposed method.

Beijing People's Association for Friendship with Foreign Countries Held 2022"Colourful World"International Youth Painting Invitational Exhibition——Mauritian Exhibition and Award Ceremony

On January 7,the 2022"Colourful World"International Youth Painting Invitational Exhibition——Mauritian Exhibition and"Chinatown Light"Award Ceremony was held at the Chinatown Art Centre in Mauritius.The exhibition was co-organised by Beijing People’s Association for Friendship with Foreign Countries and other organisations.

An Exploration of the Water Painting Method in Ancient China

In traditional landscape painting in China,water has always occupied an important artistic position and space,and painters in different ages had different ways to express water.Systematically sorting out the methods of water painting in Chinese painting is of great significance for us to gain a comprehensive understanding of the artistic styles,cultures and artistic languages of different times.It is also of great reference value for those learning Chinese painting.