bluuebunny/crossref_metadata_2025 huggingface dataset:
Linear stability of a thin fluid film interacting with its surrounding bulk fluid
Authors: Mirjalili S. , Chan W. H. R.
Published: July 2021

Thin films can become unstable when attractive van der Waals forces overcome the stabilizing effects of surface tension and viscous forces. In many applications, the effect of the surrounding bulk fluid cannot be neglected when considering a thin film subject to perturbations. In this work, we examine the two limits of potential flow and Stokes flow in the surrounding bulks to derive dispersion relations in each limit. We show that the effect of the surrounding bulks cannot be ignored for many film–bulk fluid pairings and film thicknesses and present conditions for the validity of each regime. In particular, the potential-flow regime exists when van der Waals forces are sufficiently strong, while the Stokes-flow regime exists when the bulk dynamic viscosity is sufficiently large. Due to the nature of the dispersion relation in the Stokes-flow limit, several distinct scenarios are identified in the corresponding stability diagram, each involving the interplay of different forces. For example, a novel instability regime involving capillary–viscous interactions is identified for large film thicknesses. Finally, by enlisting multiple realistic fluid pairings and film thicknesses wherein such instabilities can occur, we demonstrate the practical relevance of our theoretical findings. This work enables the extension of thin film stability theory to the analysis of antibubbles, splashing molten metals and ionic liquids, Mesler entrainment of microbubbles in breaking waves, and emulsion stability.
Influence of magnetic field in the control of Taylor column phenomenon in the translation of a sphere in a rotating fluid
Authors: Sarkar Subharthi , Sahoo Bapuji , Sekhar T. V. S.
Published: July 2021

A numerical investigation has been performed to capture how the magnetic field interferes with Taylor column—a spectacular phenomenon occurring as a result of the Coriolis effect. In this pursuit, at first, we have considered the incompressible flow past a translating sphere in a rotating viscous fluid. This setup allows us to capture the Taylor column in the upstream region at critical values of inverse Rossby number (1/Ro) along with the subsequent formation of a cyclonic vortex in the downstream region as 1/Ro is increased. However, flow separation of any kind is considered to be an undesirable flow feature from industrial perspectives. We found that an application of magnetic field aligned with the motion of the sphere induces Lorentz force into the flow field that suppresses the Taylor column for lower values of 1/Ro, and, it dissolves the cyclonic vortex formed at higher values of 1/Ro. The strength of the Coriolis and Lorentz forces, their mutual interaction, and the value of inverse Rossby number determines the growth and decay of the Taylor column and the cyclonic vortex, thereby, regulating the ultimate nature of the flow.
Putting the DOT on IL1A
Authors: Olan Ioana , Narita Masashi
Published: July 2021

IL-1α is an upstream component of the senescence-associated secretory phenotype. In this issue, Leon et al. (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202008101) show that DOT1L-mediated H3K79 methylation at the IL1A gene plays a key role in its induction during oncogene-induced senescence.
Zinc binding alters the conformational dynamics and drives the transport cycle of the cation diffusion facilitator YiiP
Authors: Lopez-Redondo Maria , Fan Shujie , Koide Akiko , Koide Shohei , Beckstein Oliver , Stokes David L.
Published: July 2021

YiiP is a secondary transporter that couples Zn2+ transport to the proton motive force. Structural studies of YiiP from prokaryotes and Znt8 from humans have revealed three different Zn2+ sites and a conserved homodimeric architecture. These structures define the inward-facing and outward-facing states that characterize the archetypal alternating access mechanism of transport. To study the effects of Zn2+ binding on the conformational transition, we use cryo-EM together with molecular dynamics simulation to compare structures of YiiP from Shewanella oneidensis in the presence and absence of Zn2+. To enable single-particle cryo-EM, we used a phage-display library to develop a Fab antibody fragment with high affinity for YiiP, thus producing a YiiP/Fab complex. To perform MD simulations, we developed a nonbonded dummy model for Zn2+ and validated its performance with known Zn2+-binding proteins. Using these tools, we find that, in the presence of Zn2+, YiiP adopts an inward-facing conformation consistent with that previously seen in tubular crystals. After removal of Zn2+ with high-affinity chelators, YiiP exhibits enhanced flexibility and adopts a novel conformation that appears to be intermediate between inward-facing and outward-facing states. This conformation involves closure of a hydrophobic gate that has been postulated to control access to the primary transport site. Comparison of several independent cryo-EM maps suggests that the transition from the inward-facing state is controlled by occupancy of a secondary Zn2+ site at the cytoplasmic membrane interface. This work enhances our understanding of individual Zn2+ binding sites and their role in the conformational dynamics that govern the transport cycle.
Predicting topological materials: symmetry-based indicator theories and beyond
Authors: Zhang Tiantian , Murakami Shuichi
Published: July 2021

Though symmetry-based indicators formulae are powerful in diagnosing topological states with a gapped band structure at/between any high-symmetry points, it fails in diagnosing topological degeneracies when the compatibility condition is violated. In such cases, we can only obtain information of whether there is a band degeneracy at some high-symmetry points or along some high-symmetry lines by the compatibility condition. Under the framework of symmetry-based indicator theories, we proposed an algorithm to diagnose the topological band crossings in the compatibility condition-violating systems to obtain the whole topological information, by using the symmetry-based indicator formulae of their subgroups. In this paper, we reinterpret the algorithm in a simpler way with two material examples preserving different topological states in spinless systems with time-reversal symmetry, discuss the limitation of the symmetry-based indicator theories, and make further discussions on the algorithm applying in spinful systems with time-reversal symmetry.
Verification of an in situ calibrated optomechanical accelerometer for use as a strong ground motion seismic reference
Authors: Pratt Jon R , Schlamminger Stephan , Seifert Frank , Newell David B
Published: July 2021

Optomechanical accelerometers offer in situ traceability to the international system of units through laser interferometry, providing an alternative to a calibration chain using instrumented shakers. Here, we examine the ‘self-calibrating’ property of a prototype optomechanical accelerometer for use as a seismic reference. We report the optomechanically derived sensitivity of the accelerometer and compare this in situ calibrated output to input accelerations from an instrumented shaker, finding agreement to be within ±1%. The comparison spanned frequencies between 3 Hz and 30 Hz, and for sinusoidal accelerations with amplitudes ranging from 0.01 m s−2 to 0.6 m s−2. These results are evidence that optomechanically derived sensitivity calibration can be equivalent to established international methods for primary calibration.
Application of the modified self-organizing migration algorithm MSOMA in optimal open-loop control problems
Authors: Panteleev A V , Rakitianskii V M
Published: July 2021

The article discusses the application of the metaheuristic algorithm of global constrained optimization for solving the problem of finding the optimal open-loop control for nonlinear continuous deterministic dynamical systems. The quality of control is assessed by the value of the functional defined on individual trajectories. The optimal control problem is reduced to a parametric optimization problem, which is solved using the MSOMA algorithm, which belongs to the evolutionary group. The MSOMA algorithm is a new algorithm based on the SOMA self-organizing migration algorithm. A step-by-step algorithm for piecewise-constant, piecewise-linear, quadratic spline and cubic spline methods of control laws approximation is proposed. The effectiveness of proposed method is demonstrated by the example of solving the problem of optimal control of a chemical process in a mixing reactor and a singular problem of optimal control. The influence of the parameters of the MSOMA algorithm on the quality of the obtained result is investigated. Comparison of the operation of the algorithm with a known solution, as well as with a solution using the original SOMA method is carried out.
Evaluating key ideas for teaching electromagnetic radiation
Authors: Zloklikovits Sarah , Hopf Martin
Published: July 2021

Although electromagnetic radiation is an omnipresent phenomenon in our everyday life, in Austria it is only taught in high schools. Our aim is to develop a research-based teaching and learning sequence on electromagnetic radiation for the middle school level. As a first design step, we developed central explanations, so called key ideas, to introduce the term of electromagnetic radiation and the interaction with matter. Those key ideas were evaluated with teaching experiments, using the method of probing acceptance. The outcomes are encouraging and help us to get a better understanding of students’ problems and their perspectives while learning about radiation. The key ideas were adapted accordingly.
The interplay between mathematics and physics in prospective primary teacher education
Authors: Lavagnini M , Michelini M , Pospiech G
Published: July 2021

Mathematics and sciences, in particular physics, are structurally related to each other. Understanding the specific nature of these subjects and their reciprocal interplay is important particularly for future teachers in primary school, where they have to be competent in building the literacy starting from a multidisciplinary perspective. One basic aspect of the educational process in primary school is the gradual building of scientific thought. The primary teachers’ competence is based on different disciplinary areas and cultural spheres related to each other. The weak competence in the mathematical and scientific scope has to be transformed into the capacity to offer a grounded scientific education and mathematical instruction, accompanying the identification of the disciplines with concrete examples from everyday life. Therefore primary teachers need insight into the basics of the subjects. This research analyses the spontaneous ideas about the relationship between math and physics of prospective primary teachers attending the course of primary education at the University of Udine. Results of a teaching intervention module focused on the reflection on this aspect are analyzed in the framework of corresponding models in literature in order to study the problem of how to improve teachers’ awareness about the Interplay between Mathematics and Physics (IMP).
The argumentative design principles of three courses in a Physics undergraduate teacher education program
Authors: Figueira Maykell , Nardi Roberto
Published: July 2021

To assure that current science education practices are aligned with recent educational research findings, there must be a constant effort of investigating the environments in which teachers are educated and prepared for their pedagogical action. One of the epistemic practices that should be discussed and taught in every teacher education program is argumentation. Preparing future teachers to construct and evaluate arguments and enabling them to design activities that scaffold students’ argumentative skills has become a highly desirable goal in science education in the past few decades. Despite that, few studies have been devoted to studying the role of argumentation and argumentative development in initial and continuing teacher education. The present study was aimed at observing and analyzing some of the characteristics of three courses of an undergraduate Physics teacher education program at a public university in the State of São Paulo (Brazil), and to compare them in terms of their potential contributions to the development or argumentation skills of its students. Preliminary results suggest that the curricular reform that has been implemented was responsible for shifting practices to a much more updated and theory-informed model, but the program’s focus is still on written instruction, and not on the development of oral communication skills, which would be key for a fertile argumentative development.
An Efficient Intravenous Drip System For Hospital Enviroment
Authors: Shanmugam Kalimuthu , Ranganathan Nishithashree , Rajaendran Vigneshkumar , Arunkumar M. , Sangeetha R.
Published: July 2021

Healthcare system plays important role in leading a happy life of increased birth rates. At healthcare, preserving the safety of patient is by far the most important matter. Advanced health monitoring systems seem to be the most sought after anyway they offer accurate information while decreasing the hospital’s medical professionals as well as attendees’ stress and over absence of many crucial information. It also is a tedious process and a harder task to demonstrate that a long and tiring method and a harder job is when the injected supplied to a fall’s prevention under a crucial quantity A simpler task is to manually monitor the level of inject able fluid, if not then done with the utmost care, the safety of an individual can be severely affected. This may result to blood or plasma flow becoming diverted through the bloodstream to the Drip tube. When the container is drained fully, air enters its tubing but in exchange enters the vein, which could be disastrous for the patient. So, it would prove very helpful to optimize this system. The blood glucose in the insulin travel container in use in clinics in this study was identified in this study. In this, whenever the IV drip was to be drained, the scheme we had also formed to connect two streams at a same intersection and access the network using control valves system of the Arduino is engineered so that if the injected reaches a dangerous threshold, It is sensed through the use of water content as well as the secondary moving fluid valve is stimulated. This requires use of the control valve as well as the flow analysis software to calculate the measured value.
Simulation troubleshooting and optimization of internal rearview mirror optical dithering problem
Authors: Su Jintao , Lou Jianping , Jiang Xiaolu
Published: July 2021

In order to solve the optical dither problem of the inside rearview mirror of a certain vehicle, the finite element modeling and modal simulation analysis of the inside rearview mirror were carried out by using MSC NASTRAN software. Based on the results of the simulation analysis, the structure of the mirror rod and the base was optimized to improve the stiffness and modal, and the scheme was engineered and verified, which effectively solved the optical dithering problem of the rearview mirror.
A Qualitative Comparative Analysis of the Academic Media Using Frequency on Networking Platforms
Authors: Ye Ranling , Xu Jie , Zhang Na
Published: July 2021

This paper takes the determinants of the academic social media using frequency of Chinese young scholars as the research topic, aiming to get the causal relationship between the factors and the academic social media using frequency of young scholars. Based on the Expectation-Conformation Model, the Technology Acceptance Model and existed research results, this paper constructs an analysis framework according to two elements of which are users’ characteristics and perception effects. By using Linear Regression and Qualitative Comparative Analysis, this paper makes a comparative analysis of the following factors; they are literature acquisition, recommendation function, effect of use, purpose of use and discipline. The conclusion of Linear Regression is contrary to the empirical theory and practical knowledge, which means the weak applicability of this method to this research topic. While Qualitative Comparative Analysis can be more reasonable to analyze the configuration that led young researchers to use academic social media more frequently.
Research on the Application of Artificial Intelligence Technology in the Field of Sports Refereeing
Authors: Chen Xin
Published: July 2021

This article uses artificial intelligence machine vision technology to design a method for judging violations of passing passes. First, use Adaptive Enhanced Variant Algorithm (GAB) to train the classification model to complete the detection of sports (badminton and racket); combine the detection area to extract the sphere center coordinates are used as the target point, and the detected racket part is constructed as the target area. Then the position relationship between the two is defined, and the judgment key frame is extracted according to the relative position change relationship between the target point and the target area; finally, the image angle representation method is used to establish the state judgment model takes the state of the racket in the judgment key frame as an input, and quantizes the output result as an angle value, so as to realize the judgment on whether to serve the ball.
Mechanical analysis of bone and its internal fixation
Authors: Gao Xinyi
Published: July 2021

Biomechanics can help people understand the work of the human body and organs, as well as the changes of various effects under the action of external loads, to carry out artificial control and prediction. Bone biomechanics is an important branch of biomechanics, and bone materials are divided into four hierarchical structures, starting from the lowest molecular level, to woven bones, lamellar bones, and Haversian bones, then a higher level of large woven bones and primary woven bones, Harversian bone system and laminar bones, at last to the macroscopic level compact bones and cancellous bones. The analysis of bone mechanical properties focuses on the elasticity modulus parameters, the elasticity modulus of dry bones is usually greater than that of wet bones, and the elasticity modulus of compact bones is usually greater than that of cancellous bones. As well as the stress relaxation and creep behavior of compact bone, the 8 microstructure parameters of cancellous bone. Combined with the mechanical analysis of fracture and internal fixation in clinical medicine, the connection method between the steel plate and the bone, the position of the steel plate relative to the bending direction, the selection of materials and other factors affect the mechanical properties, so that various factors need to be paid attention to in the analysis of surgery.
Design and Application of Tibetan Long Chess Using Monte Carlo Algorithm and Artificial Intelligence
Authors: Zhou Junjie
Published: July 2021

In order to study the algorithm of Tibetan Jiuqi, a new kind of chess in Chinese computer game, there are too many possibilities to be considered in solving the problems of falling pieces, and the influence of falling pieces on Xingzi and Tiezi. On the basis of forming different chess patterns as the main source of raising pieces, this paper puts forward a design scheme which takes the Monte Carlo algorithm randomly as the core and the final evaluation algorithm as the secondary one, and takes a variety of possibilities in Tibetan chess as a breakthrough. Get different benefits from different chess types to cooperate with the final evaluation algorithm to get the assignment of each replicated chessboard. It is proved by the program computer game that the program is complete and the three stages of Tibetan chess can be completed successfully. The experiment shows that the Monte Carlo algorithm is very suitable for the AI development of Tibetan chess.
Noise Reduction Design of Steam Control Valve
Authors: Xingsheng Lao , Xian Gong , Lu Dai , Weijian Lyu , Wei Zhang
Published: July 2021

The internal steam fluid pressure pulse force is the excitation source of control valve. Based on the Lighthill equation and the orifice injection shunt noise reduction theory, the flow noise and air noise calculations of throttling devices are carried out for the eccentric rotary control valve and the cage sleeve control valve, and the design improvements are presented for noise control of the valves. When there is no noise reduction internals, the air noise caused by the steam control valve with a pressure of 4.5MPa in front of the valve is greater than 95dB. The preset orifice plate reduces the pressure in the control valve to 50% of that before the valve, then the small hole Shunt method for noise reduction can be employed. When the two-stage orifice plate is installed and the number of second-stage holes is greater than 100, the air noise of the eccentric rotary steam control valve is lower than 80dB, and the first-stage orifice plate is installed. The air noise of the bored sleeve type steam control valve with preset orifice plate is also lower than 80dB, but it is easier to meet the low noise design requirements of the steam control valve than the improving method used in above sleeve type steam control valve.
A service encapsulation method of NC machine tool resources in cloud manufacturing
Authors: Chao Yin , Junxu Chen , Bo Li
Published: July 2021

NC machine tool resources are important manufacturing resources in cloud manufacturing. How to carry out semantic description and service encapsulation of heterogeneous, decentralized and autonomous NC machine tool resources is one of the key technologies to realize the cloud manufacturing mode to the workshop level. In order to solve the problems such as encapsulation complexity and lack of specification in the process of service encapsulation of NC machine tool resources in cloud manufacturing, this paper first analyzes the basic attributes, functional attributes and other attributes of NC machine tool resources in cloud manufacturing. Then, a semantic description method of NC machine tool resources based on XML language is proposed. Finally, a service encapsulation method of NC machine tool resources based on JAX-WS is put forward.
Numerical Simulation of Mechanical Characteristics of a Gas Generator Grain under Temperature Load
Authors: Jian-bin Zhang , Ben-shuai Fu , Shao-feng Gong , Ke Liu , Dong Cheng
Published: July 2021

In view of the crack phenomenon in the low temperature storage process of a certain type of gas generator, the viscoelastic finite element method is used to study a certain type of adherent cast solid gas generator grain, and the numerical simulation study is completed. The simulation results show that the stress concentration on the inner surface of the star shaped grain is located at the B point of the arc of the star root during the process of cooling and low temperature. At the initial moment of curing stage the rising trend of stress and strain of B point is not obvious, before the end of cooling stage the linear increases with the increase of time. During the low temperature storage, the stress relaxation and creep behavior are not obvious. The maximum stress of the B point is 0.289MPa, and the maximum strain value is 16.881%. The simulation process assumes that more simplification is made, and the actual maximum strain value may have more than 20%, which may lead to the crack phenomenon. It lays a foundation for the optimization of the propellant formula and the structure of the grain.
The establishment of a three-dimensional simulation model of the Queen of Song Dynasty “HUIYI”
Authors: yuqing Yang , yue Li , xiaogang Wang
Published: July 2021

In the application and development process of 3D simulation technology, it is found that the research on traditional Chinese clothing models is still relatively lacking. In order to realize the establishment of the digital virtual model of Chinese traditional costumes, this article takes the Song Dynasty queen “Huiyi” as the research object, and derives the production methods and materials of the Song Dynasty queen “Huiyi” through the analysis of known documents and image data. Using virtual simulation modeling technology, establish a three-dimensional model of virtual clothing display, so that traditional clothing can be quickly and accurately restored. Establish a three-dimensional virtual simulation model on the basis of in-depth research on plane plate making, patterns, materials, to further expand the research on the digital technology of traditional Chinese clothing, and to lay the foundation for three-dimensional simulation. It provides a new direction and method for the inheritance of Chinese traditional costumes.
The conception and exploration of the underwater vehicle simulator
Authors: Shao-feng Gong , Jian-bin Zhang , Dong Cheng , Hai-Yan Xiao , Ping Dong , Zhan-sheng WU
Published: July 2021

In this paper, a new type of underwater vehicle simulator is proposed. The underwater vehicle simulator adopts capsule prefabrication structure and can be carried on UUV Each UUV can be loaded with multiple underwater vehicle simulator capsules. After sailing to the predetermined location, long-distance delivery is carried out. After the underwater vehicle simulator is fully charged and expanded, the underwater vehicle simulator cluster is formed to achieve tactical purposes such as confusing and inducing enemies in quantity, orientation and deployment. The technology can be applied to the new generation of underwater vehicle safety defense system, and can be popularized and applied to other weapon systems. It has great military, political and national defense significance and has broad application prospects.
Design and simulation of key mechanism for transverse sealing of fresh food packaging machine
Authors: Zheng Zhaoqi , Shi Bingjian , Mei Wenjuan , Liu Chaoran , An Zimin , Shi Pu , Wang Ruifang
Published: July 2021

In order to improve the freshness and safety of fresh food, packaging is necessary for the processing industry of agricultural products. At present, the packaging of fresh food in China is mainly manual packaging, which has high labor intensity and low production efficiency. In response to this situation, this study focused on the transverse sealing device of the fresh food packaging machine. The device completed the transverse sealing operation through the cooperation of two main mechanisms, including an up wind box and an anthropomorphic hand folding mechanism. The anthropomorphic hand folding mechanism was composed of roller, cylinder and lower wind box. This paper makes a study of design and simulation of key mechanism for transverse sealing of fresh food packaging machine, improving the completion of the transverse sealing of the packaging machine. The experiment showed that the designed structure basically satisfied the functional requirements of the fresh food packaging machine for the sealing operation of the transverse sealing device. And the optimal parameter of the air outlet of the up wind box was 640 mm2, the lower wind box of anthropomorphic hand folding mechanism was 19 air outlets with a diameter of 2 mm.
Silulation on Parallel Control Mthods of Isoland Microgrid Powered bylnverter and Diesel Generator
Authors: Xiaolin Zhang , Fan Ma , Chun Li
Published: July 2021

Aiming at the power quality problems caused by the large number of renewable energy access to the grid, three common parallel networking modes of inverters and diesel generators in the independent micro-grid were analyzed in this paper, this paper also makes a systematic and comprehensive comparsion from the control principle, control structure, control performance, overall resource occupation, deduced the equivalent conditions of droop control and virtual synchronous generator control. Secondly, the characteristic of different control methods was analyzed to test the stability and also point out the characteristic of voltage and current in this paper. Finally, the micro-grid model was builted on PSCAD/EMTDC platform to verify the performance of three methods from the conditions of parallel off grid switching, load mutation and three-phase short circuit fault, and also point out the application scope of different strategies, it has reference value for micro-grid engineering practice.
Design of Real-time Monitoring System for Liquid Flow Standard Device Based on Internet of Things
Authors: Jiamin Lu , Ping Wang
Published: July 2021

In order to improve the level of information and artificial intelligence of liquid flow standard devices, a real-time monitoring information exchange platform system of Internet of Things for standard devices is built in this paper. By introducing artificial bee colony algorithm to optimize BP neural network algorithm, the data of the Internet of Things system can be analyzed and provided to users, so as to improve the artificial intelligence level of the whole set of standard devices. Simulation and experiment show that the system for liquid flow standard device proposed in this paper works stably and reliably, and all the indicators meet the testing requirements of standard devices.
Design of Data Acquisition System in Tobacco Industry Based on Industrial Internet of Things
Authors: Lin Jingju , Liao Junhui , Zhang Zhibin , Lin Hui , Zhang JianWei
Published: July 2021

This article adopts the Internet of Things technology, network communication technology, edge computing and other technologies to establish a set of data acquisition system based on the industrial Internet through the data collection, storage and reporting of the automatic control systems of the three workshops of silk making, wrapping, and power and other related information systems.
Research on Obstacle Avoidance of Small Cruise Vehicle Based on Improved Artificial Potential Field Method
Authors: Xiaojie Liu , Yinke Dou
Published: July 2021

To enhance the small cruise vehicle in the complex environment under the ice autonomous obstacle avoidance ability, the artificial potential field algorithm was improved in this paper. Firstly, the idea and principle of the traditional artificial potential field obstacle avoidance algorithm as well as its existing defects such as local minimum are analyzed. Then the local minimum defect of the traditional artificial potential field method is solved by optimizing the repulsive potential field function and adjusting the repulsive force component’s direction on the coordinate axis. Then, the improved artificial potential field obstacle avoidance algorithm is simulated by using MATLAB software. The experimental results show that the improved algorithm can make the cruiser safely and accurately sail to the target position without falling into the local minimum value, which proves that the improved artificial potential field obstacle avoidance algorithm can work safely and stably.
Modal analysis of excavator toolbox based on hypermesh
Authors: Wang Mengyao , Dong Mingming , Lu Shen , Hu Yaoguang
Published: July 2021

Excavator is one of the most important construction machineries. Its working environment is complex and changeable. There is no perfect suspension system for excavator as cars, and the covering parts are mostly thin-wall welded parts. Therefore, the covering parts are easy to be damaged in the working process, which brings poor using experience problems to users. According to the user feedback survey, toolboxes are most prone to cracking in the cover. The quality of the toolbox determines the company’s reputation and brand competitiveness in the market to a certain extent. Therefore, it is important to study the vibration response of the toolbox. Aiming at the problem of box body cracking in the road test of a medium-sized excavator toolbox, this paper carried out modal simulation and test verification on the excavator toolbox, laying the foundation for the follow-up research.
Analysis of Subgrade Vibration and Dynamic Stress of Heavy Haul Railway with High Embankment based on ZL-TNTLM Program
Authors: Shujun Yan , Yousheng Deng , Lei Hao , Jian Li , Xueli Zhang
Published: July 2021

Aiming at the high embankment section of heavy-load Railway, a finite element model of dynamic response of subgrade structure under train load is established, and ZL-TNTLM program is used to apply load excitation. The results show that the dynamic stress on the top of the roadbed is a single peak curve under heavy train load, and the peak value of the vertical acceleration vibration changes obviously under heavy train load, and presents a periodic change With the increase of the train speed, the dynamic pressure stress of the track bed and the foundation bed does not increase obviously with the increase of the train speed, but fluctuates and changes slowly; the dynamic stress and the vertical acceleration in the roadbed attenuate non-linearly along the depth direction The attenuation of acceleration is greater than dynamic stress along the direction of subgrade depth. The results are of theoretical and engineering significance for revealing the dynamic stress and vertical acceleration mechanism of heavy-haul railway subgrade under the change of high-speed train speed.
Research on the Ming Dynasty Dao Robe Modeling Method Based on 3D Simulation Technology
Authors: song Ma , yue Li , xiaogang Wang
Published: July 2021

With the rapid development of 3D virtual fitting technology, the study of virtual simulation models of traditional Chinese clothing is of great significance to the establishment of a visual database. In this article, the Ming Dynasty Dao gown is taken as the research object. First, the method of combining historical documents and archeological objects is used to analyze the Dao gown’s clothing culture, plane structure, and modeling characteristics in depth. Use virtual simulation technology to establish a three-dimensional model, and simulate and reproduce the color pattern, fabric material, human body proportion, and replica modeling of the robe. In the research of this thesis, the clothing CAD technology is used to restore the historical pattern and the three-dimensional simulation technology to show the effect of the ready-made clothing, and more concretely reproduce the clothing shape and style characteristics of the Ming Dynasty Taoist robe. The modeling method of 3D simulation technology provides new ideas for the reproduction and reproduction of visualized Chinese historical costumes and the promotion of the digital inheritance of Chinese historical costumes.
Modelling and simulation calculation of fixed-cylinder hydro-pneumatic suspension
Authors: Chen Yijie , Huang Long , Xu Long , Zheng Guanhui , Wang Le
Published: July 2021

According to the structural characteristics of the fixed-cylinder hydro-pneumatic suspension, the force transmission and the construction of the theoretical model were discussed. The non-linear correspondence of the force between the piston and the road wheel was clarified through analytical deduction, and the formula for calculating the stiffness of the suspension was given. The influence factors of suspension leverage ratio and elastic force were simulated and analysed by programming, the conclusions drawn provided ideas for the design of zero stiffness suspension near the equilibrium position.
Improvement of tensioning roll for aluminum foil cutting assembly of ZB48 packaging machine
Authors: Guoqian Ye , Yonglong Yu , Yuming Xu , Guofu Luo
Published: July 2021

In the operation process of ZB48 dual-channel ultra-high speed cigarette packing unit, the fault downtime of aluminum foil cutting assembly is long, which accounts for 77.4% of the total downtime, and the main phenomenon is caused by the falling of aluminum foil. The cam-like appearance of the aluminum foil paper tightening roll is designed to ensure that the total length of the periphery is equal to that of a piece of aluminum foil paper, and the power transmission mode is optimized to eliminate the phenomenon of falling off the torn pieces of aluminum paper. The results show that the aluminum foil cutting component based on the new improved tensioning roller meets the requirements of the continuous and stable operation of the ultra-high speed packaging unit. Through six months of tracking analysis, the average daily shutdown time of the aluminum foil components is reduced to 5.6 minutes, which reaches the predetermined target.
Finite Element Analysis of Glass Fiber Winding Molding of HDPE Pressure Vessel
Authors: Zeng Wenlei , Hu Wenhua , Liu Huan , Tian Haobin
Published: July 2021

Type IV low-pressure vessel formed by non-geometric winding of glass fiber composite materials are taken as the object. The number of winding layers, winding line type and thickness of the winding layer of the vessel are designed by the method of CADWIND numerical simulation. Finally, with finite element software for stress and strain analysis. The middle part of the pressure vessel is wound in a combination of hoop winding and spiral winding, and finite element modeling is carried out using CADWIND winding professional simulation software. According to the trajectory of non-geometric winding forming, the optimal winding parameters of the composite pressure vessel are determined; the design parameters such as fiber winding thickness, winding angle and number of winding layers are determined. The finite element model of the pressure vessel was established and exported on the basis of CADWIND simulation software, and the finite element simulation software was used to verify and analyze the thickness of the winding layer. The results show that when the internal pressure of 1.5MPa is applied, although the head is easily damaged, it is not enough to make the pressure vessel invalid. The research in this paper can provide reference for the design and use of glass fiber composite material low pressure vessel.
Analysis of the influence of oscillator stiffness parameters on vibration transmission characteristics of Drude model acoustic metamaterial with series double harmonic oscillators
Authors: Huijie Shi , Ming Gao , Enxin Hu , Dongfu Yan , Zhiyuan Zhang , Lin Du
Published: July 2021

For a kind of acoustic metamaterial with special microstructure and attenuation band gap, the vibration transmission characteristics of five period Drude system with series double harmonic oscillators are analysis to uncover the widening band gap method. The harmonic oscillator stiffness parameters are changed to expand the range of band gap width. The increase of parameter k
1 will widen the high frequency band gap width, and the increase of k
2 will widen the low frequency band gap width. In band gap region, under the steady state, the first harmonic oscillator in five period motion direction will change from consistent to inconsistent as the parameter k
1 change. The conclusion in pass band region is similar. The research provides technical approach for promoting the development of vibration and noise control in engineering.
Structural characteristics and strength analysis of main hull of cylindrical FPSO
Authors: Yun Xie
Published: July 2021

In this paper, a cylindrical FPSO is analyzed. Firstly, the structural characteristics and structural layout principles are introduced. The overall structural model of the main hull of the cylindrical FPSO is established by using the three-dimensional finite element design software. According to the actual situation in the operation process, the boundary conditions and load cases are determined. Finally, the yield strength of the main hull is checked. This paper has a certain guiding significance for the design of cylindrical FPSO.
Application of genetic algorithm to optimize the impact resistance of composite laminates
Authors: Yang Runze , Wu Zhirong , Fang Lei
Published: July 2021

The impact resistance of composite fan hood is of great significance to improve the safety of engine. Taking the fiber reinforced resin matrix composite laminate for Aeroengine fan case as the research object, the maximum loss kinetic energy of impact body as the objective function, and the fiber ply angle as the design variable, the impact resistance of the fiber reinforced composite laminate was optimized. ABAQUS finite element software is used to simulate the high velocity impact of composite laminates, and genetic algorithm is used to optimize the design, and the optimal stacking method is obtained. Through the optimization design, the impact resistance of fiber reinforced composite laminates has been greatly improved.
Corrosion failure analysis and microstructure characterization of emulsion on hydraulic cylinder base
Authors: Zhiwei Zhang , Fan Wang , Sufen Liu , Hongwei Zhou , Wenyuan Geng , Zhaojie Li
Published: July 2021

This paper studies the corrosion of the base of the 30CrMnSi hydraulic cylinder due to changes in emulsion concentration during maintenance and its effect on alloy performance. The results show that the corrosion characteristics of the base of the hydraulic cylinder are comprehensive corrosion and local point corrosion, and that the anti-rust performance of emulsion in contact with the outer surface of the hydraulic cylinder base is insufficient, and the chemical reaction with its surface is the main cause of the corrosion of the components. According to the analysis, the hydraulic cylinder base can not be stored at a reasonable emulsion concentration, resulting in a decrease in its surface pitting potential, so that its ability to cope with environmental corrosion decreased, after a period of time, rust on its surface.
Early hydration behavior of novel amphoteric polymer in cement paste
Authors: Ke Yuliang
Published: July 2021

The development of the early strength of the concrete mainly depends on the early hydration process of the cement, and there are many factors influencing the early hydration process of the cement. It is of great significance to study the mechanism of the polymer on the cement hydration for the development of the product. The amphoteric polymer was synthesized by (2-propenyloxyethyl) trimethyl ammonium chloride, acrylic acid and isopentene polyoxyethylene ether with different molar ratio. The chemical structure of polymer was characterized by GPC, and the performance of cement with polymers was observed by isothermal calorimetry and compressive strength of mortar. The results showed that the new amphoteric polymer has a strong promoting effect on the early hydration of cement. With the increase of the amount of (2-propenyloxyethyl) trimethyl ammonium chloride, the hydration speed is faster, but the addition of amphoteric polymer results in the decrease of fluidity of cement paste, so it is necessary to control its amount reasonably.
Enhanced stability and performance of inverted perovskite solar cell using titanium interlayer
Authors: Sun Tian , Lin Xiaoyun , Wang Ya , Zhong Hong , Zhou Hang
Published: July 2021

Metal atom diffusing in perovskite solar cells (PSCs) results in pernicious effects, leading to degradation of efficiency and long-term stability. Here we report the potential of titanium (Ti) acting as permeation barrier interlayer between organic layer and metal electrode. The thin, compact titanium layer not only insulates active layer from external moisture, but also keeps metal electrode from further corrosion. By introducing titanium interlayer, open circuit voltage (Voc) and fill factors (FF) are both enhanced, presenting a power conversion efficiency of 20.52% (Voc of 1.127 V, Jsc of 22.136 mA/cm2, FF of 82.299%). Furthermore, the unencapsulated devices maintain 98.3% of their initial efficiency after 85°C thermal aging in ambient atmosphere (air, Relative Humidity: 50%-60%) for 55 hours.
Red loam soils blocks modified using cement-lime: Assessment of its optimum ratio, performance, and practice
Authors: Zhang Fupeng , Shi Lei , Liu Simian , Zhao Mingqiao , Ma Qian
Published: July 2021

This paper reports the optimal ratio of cement-lime modified rammed earth materials for red loam soils in the Changsha area. The optimal moisture content of 8%∼12% was determined by key indicators such as test block effect, compressive strength, and weather resistance. Subsequently, the physical properties, water resistance, and weather resistance of red loam soil blocks with different cement and lime ratios were compared, and the suitable ratios of cement-lime modified rammed earth material for the Changsha area were determined as follows: soil: sand: stone: lime: cement - 5:3:2:1/3:1:1. To verify the reasonableness and practicability of the experiments, the rammed simulated tests and practical applications were carried out.
Orthogonal experimental study on preparation of water glass from biomass ash
Authors: Liu Ao , Zuo Huimin , Zhang Peng , Zhou Mingyuan
Published: July 2021

Using fly ash from biomass power plant as raw material, sodium silicate was prepared by alkali melting method under normal pressure. Orthogonal experiments were designed to explore the effects of NaOH solution concentration, solid-liquid ratio (ratio of NaOH solution volume to biomass ash mass), reaction temperature and reaction time on the dissolution rate of SiO2 and the modulus of sodium silicate. The results showed that the optimal solution was NaOH concentration of 1mol/L, solid-liquid ratio of 1:4, reaction temperature of 120°C and reaction time of 4 hours. According to the experimental verification, the dissolution rate of silicon dioxide and the modulus of water glass in the optimal scheme reach 56% and 2.43, respectively, which is the best experimental condition.
Study on mechanical properties of lightweight and high strength polyurethane cement composite (PUC)
Authors: Gao Hongshuai , Dong Yaqiao , Zhang Kexing , Liu Hongbo
Published: July 2021

Polyurethane cement composite (PUC) has the characteristics of low density and strong bending and tensile strength. Firstly, the composition of PUC is introduced and analyzed. Then, the preparation method of PUC is proposed. It is found that molding time of PUC sample can be adjusted by catalyst, and the key step is drying and dehydration of cement during the preparation process. Finally, PUC specimens with four mixture ratios are prepared according to proposed preparation method, and compressive and bending tests are carried out. Test results show that, PUC has ductility and toughness; with mixture ratio decreasing, strength changes with a little range, but elastic modulus increases.
Talking about the New Uses of Several Inorganic Antibacterial Materials
Authors: Wu Zexin
Published: July 2021

In recent years, the outbreak of a variety of infectious diseases has had a significant impact on human health and social economy, so the research on antibacterial materials has become very important. The author sorted out and analyzed the principle preparation and related applications of the three current inorganic antibacterial materials, summarized their new uses in life, and discussed zinc-type composite inorganic antibacterial materials, zinc-europium antibacterial materials and zinc-Holmium antibacterial silica new antibacterial materials currently have some limitations and a bright vision for future research.
Printed hydrogels with orderly distributed nanowire
Authors: Gao Tinghao , Zhao Weiwei , Chen Lijin , Hu Sanming
Published: July 2021

Nanocomposite hydrogels have diverse properties and considerable advantages in biomedical applications when compared with pure hydrogels. In this work, a CNT-pHEMA hydrogel composite is constructed using 3d printing. CNTs are distributed in an orderly manner inside the hydrogel matrix. The mechanical properties of this hydrogel have been characterized in terms of their anisotropic tensile modulus, which thereby proves the orderliness of embedded CNTs. The reported 3D printing method on manipulating the directions of nanowires inside the hydrogel can help the development of flexible smart components with complex characteristics in various applications.