bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantitative Analysis of Higher Education Based on AHP-TOPSIS
Authors: Qi Hao , Wang Yuanshen , Liu Lvcen
Published: December 2022

The development of higher education is a hot topic in today’s era. To solve the problem of the imperfect evaluation system of multiple universities, this paper collects data from various universities in the Yangtze River Delta in China. It applies AHP-TOPSIS to score and evaluate different universities. We took the Yangtze River Delta region in China as an example to comprehensively evaluate universities. The scale of higher education in the Yangtze River Delta region and the quantity of higher education resources are at the top level in the country. Still, the quality of higher education in multiple universities is uneven. We need to select indicators to evaluate the universities in the Yangtze River Delta comprehensively. Thirty colleges and universities in the Yangtze River Delta region were sampled for the comprehensive evaluation. We collected six items, including the number of academicians in colleges and universities, the number of papers published in scientific journals such as Nature and Science, the number of critical disciplines, the number of national-level specialty majors, the number of master’s programs in first-level fields, and the number of doctoral programs in first-level fields. According to the Analytic Hierarchy Process (AHP), we get the weights of the six indicators as 0.1389, 0.1475, 0.1872, 0.1872, 0.1595, and 0.1796. Indicators are established to score colleges and universities based on the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) and Analytic Hierarchy Process (AHP). The evaluation and ranking of universities in the Yangtze River Delta conducted in this paper are based on the combination of AHP and TOPSIS (AHP-TOPSIS).
Regularized K-means Clustering for Multi-View Data
Authors: Yu Miao
Published: December 2022

Clustering is a common problem in machine learning. Multi-view data can better express the integrity of data because most of the data currently processed is single-view data. Therefore, the problem of clustering analysis of multi-view data has attracted a lot of attention, and how to improve the accuracy of clustering analysis of multi-view data has become a hot topic. We propose the regularized K-means (RKM) algorithm to deal with multi-view data, based on the K-means algorithm, add regularization terms, which can avoid data overfitting. Through numerical analysis, the RKM significantly improves clustering performance to the comparison methods.
Numerical Simulation and Experimental Research on Oil Film Characteristics of High-Pressure Piston Pump Slipper Pair
Authors: Zheng Xiaofeng , Liu Tianbao
Published: December 2022

The high-pressure axial piston pump is widely used in the field of coal machinery equipment due to its compact structure, high power density, and easy variable control. Failure affects pump performance. In this paper, the sliding shoe pair of the high-pressure plunger pump is taken as the research object, the variation law of the oil film pressure field is numerically simulated by Matlab software, and the high-pressure pump sliding shoe pair test bench is built. The full-cycle dynamic evaluation of the influence of the speed change of the drive shaft on the oil film characteristics is obtained.
Computation of Two-Dimensional Poisson Equation Using the Third-Order Discrete Scheme of Finite Difference Method Based on Node Set Vector
Authors: Luo Zhizhong
Published: December 2022

A novel third-order discrete scheme of finite difference method based on node set vector for two dimensional Poisson equation is proposed in this paper. Studies on the basic discrete scheme of this method as well as the discrete scheme of the interior node and boundary node are carried out in detail. Computer programs are also developed to emulate a computation sample. The numerical computation results show that this discrete scheme is effective for the numerical computation of two dimensional Poisson equation.
Solving Nonlinear Partial Differential Equations via Deep Galerkin Method
Authors: Ji Xinjun
Published: December 2022

This paper introduces a one-dimensional nonlinear Black-Scholes equation. Because nonlinear models are difficult to obtain analytical solutions, finite difference schemes are usually used to solve them. Numerical solutions of partial differential equations have always been a hot research topic in the frontier; the finite element method, finite body method, and other methods are commonly used in research. In general, these methods require the use of grids to approximate the definition space of PDEs. When we have a finer grid, the more accurate solution will be. However, the smaller the grid, the higher the computing cost and the larger the storage space. Therefore, the meshless method is adopted in this paper.
Numerical Simulation of Deformation and Failure Process of Tunnel Surrounding Rock Based on Different Constitutive Models
Authors: Chen Lei , Wang Qian-wei , Du Ai-hua , Ye Wu , Tao Shuai
Published: December 2022

Based on five different constitutive models, the progressive failure process of deep hard rock was simulated, and the plastic zone, shear strain increment high-value zone, horizontal displacement, and maximum principal stress distribution of surrounding rock were obtained. The calculation results show that the plastic zone of surrounding rock calculated by MCSS and HBSS models is mainly concentrated in the floor and vault of the cavern, and the sidewall is not damaged. There is no shear zone in the surrounding rock, and the magnitude of horizontal displacement is 10-4. In the L-CWFS model, the hysteresis cohesion of friction strengthening is weakened, and the initial friction angle is 0. The calculated plastic zone runs through the surrounding rock, and the whole section is destroyed. The order of magnitude of the horizontal displacement extremum is 10-3. The MC-HB model simulates the spalling failure of the side wall, and the strain localization of the side wall is not obvious, and no shear band is formed inside the surrounding rock deeply. The N-CWFS-TSS model simulates the buckling failure process of the straight wall plate crack. A shear band is formed at the bottom of the straight wall and penetrates into the interior of the surrounding rock. The strain localization is obvious and the order of magnitude of the shear strain increment is 10-2. The calculation results are consistent with the results of laboratory tests and field observations, and the failure mechanism of the compression-shear-tensile-shear composite in the progressive failure process of the surrounding rock is clarified.
Some Inequalities about Mixed Discriminant and Dual Mixed Discriminant
Authors: Liu Wen , Zou Du
Published: December 2022

Inequalities play an important role in the field of geometry, we establish some inequalities about mixed discriminants and dual mixed discriminants, which are the matrix analogous to mixed volume inequalities in convex geometry. And we prove them using some classical inequalities.
Determining the Potential Function of the Stationary Vector Burgers’ Equation
Authors: Wang Chang
Published: December 2022

We consider the inverse problem of determining the potential function of the stationary vector Burgers equations Δu – (u · ∇)u – q(x)u = 0. We give the well-posedness of the solution in H2 a small boundary value. Then, by linearization, we prove that the potential function can be determined from the boundary Cauchy data.
Fundamental theorems in Complex analysis
Authors: Chen Bofan
Published: December 2022

This article will first introduce the conception of complex numbers and then deal with some famous results in complex numbers. In the beginning, we prove the Cauchy-Goursat theorem and calculate the integral along a closed path in a domain on which the given function is analytic. We want to check the relation between a function being analytic, having primitive, and its integral along a closed path equals zero. In conclusion, for a given analytic function on a simply connected domain, integral along any closed path is zero. Using this conclusion, we can prove the residue theorem and the Cauchy integral formula. To prove the existence and uniqueness of Laurent expansion, we first prove the Laurent decomposition by the Cauchy integral formula and Liouville’s theorem. By Laurent’s decomposition theorem, we change the case into dealing with two analytic functions. But one of them is analytic at infinity. The definition of the analytic function is applied to get the result. It’s easy to notice that every singularity of a meromorphic function on a subset of the complex number is isolated. Since meromorphic functions are widely used in variable aspects, it’s important to study isolated singularities. Then by studying the unique Laurent expansion in the neighborhood of the isolated singularity, we can classify isolated singularity.
Experimental Research on Damage Detection Based on Time Domain Data and Bayesian Fusion
Authors: Guo Huiyong , Li Meng
Published: December 2022

Damages such as cracks often occur in engineering structures, and such damages often have the characteristics of time-domain variable stiffness. To effectively identify this kind of damage, a damage detection method based on time domain data and Bayesian fusion is presented in this paper. First, a hybrid model of the AR/ARCH model is used to identify structural nonlinear damage, and a damage indicator is also used: the second-order-variance indicator (SOVI). Although most of the nonlinear damage information is extracted by the indicator SOVI and ARCH model, some nonlinear information is still filtered out by the AR model part. Therefore, a linear cepstral metric indicator (CMI) based on the AR model is introduced to extract the remained nonlinear damage information, and further, the Bayesian fusion theory is applied to combine the results of SOVI and CMI to obtain complete nonlinear damage information and achieve better identification results. Finally, a three-story frame experimental model is used to demonstrate the effectiveness of the Bayesian fusion. Experimental results show that the Bayesian fusion method is superior to SOVI and CMI.
A Constant Sign Theorem for a Class of Semi-linear Elliptic Equations
Authors: Ye Yunhua
Published: December 2022

Many problems arising from physics and analytic and geometric properties of solutions to partial differential equations have strong connections with convexity. In the present manuscript, we use the level curve curvature formula to derive a differential inequality and prove a invariant sign property for a class of nonlinear elliptic problems.
Mechanical Action Mechanism and Crack Response Analysis of Slide Plate of No.12 Turnout
Authors: Chen Lei , Han Feng
Published: December 2022

In the course of maintenance and repair, the railway workshops of the Lan-Qing railway found that the slide plate was prone to injury and damage. In order to study the actual stress state of the slide plate during the running of the train, a finite element model of the slide plate and related components was established based on ANSYS, Hypermesh was used for meshing and mesh quality control, and the Mooney-Rivlin constitutive intrinsic model was selected to simulate the rubber plate. The stress state of the slide plate when passing through the turnout in the straight and lateral directions is analyzed respectively. The results show that there is stress concentration at the root of the tongue depressor of the slide plate, and large deformation exists in the middle of the base plate, the front end of the platform plate and the position of the guide iron when passing through the turnout directly and laterally. The stress state of the slide plate is simulated when the rail brace fails, and the maximum stress is found to be 279.24 MPa, which exceeds the material yield limit. Therefore, we should pay attention to the inspection of the condition of the rail brace during the maintenance and repair. Presenting cracks at the weld seam location, it is found that the crack has a significant effect on the dewelding of the slide plate, and the heel position is the weakness of the slide plate. When the crack length reaches 1.2 mm, there is a tendency to crack at the weld seam position of the slide plate, and when the crack length continues to increase, the crack will further expand and jeopardizing structural safety. The research results can provide a theoretical basis for the improvement, disease prevention and maintenance of the slide plate.
Evaluation of the Metrological Integrated Support Capability of Launch Site Based on FUZZY-AHP
Authors: Pan Xiao , Lin Yiyong , Li Dong
Published: December 2022

The metrological integrated support capability is an important part of the equipment support capability of the launch site. To realize the quantitative description and scientific evaluation of the metrological integrated support capability, the FUZZY-AHP method is introduced. Based on the study of the factors affecting the capability, the evaluation index system is constructed from four aspects of personnel capability, equipment capability, technical support capability, and comprehensive management capability. A multilevel evaluation model of the metrological support capability is established by using the analytic hierarchy process. Then, with the fuzzy mathematics method, the rules of the fuzzy evaluation for the quantitative and qualitative indicators are formulated. Finally, combined with a launch mission, the FUZZY-AHP method is used to evaluate the metrological integrated support capability. The method is scientific and feasible, which provides an effective reference for the subsequent evaluation of the metrological integrated support capability.
Lump Solution to the (2+1)-Dimensional Hietarina Like Equation
Authors: Li Xin , Jiang Kun
Published: December 2022

In this study, we first derive the (2+1)-dimensional Hietarina(H) like equation by a generalized bilinear differential operator, then solve the lump solution of the H-like equation and finally combine the basic characteristics of the understanding with graphic analysis. In addition, we calculate the learned maximum and minimum.
Big Data-aided Study of the Physical Process of Volume Ignition
Authors: Liu Pan , Zhou Yinzhao , Xiong Wenbin , Liu Chencheng , Liu Jie , Liu Gongjie , Tang Zhangchun , Gao Qiang
Published: December 2022

Volume ignition is a method of igniting a fuel as a whole by simultaneously achieving ignition conditions throughout the fuel zone. The basic criterion for ignition is that the thermonuclear energy is greater than the energy leakage at the fuel boundary, resulting in self-sustaining heating and deep combustion. Deuterium-tritium fuels are wrapped in medium to high Z media to reduce radiative leakage and achieve lower-temperature holistic ignition and non-equilibrium combustion, ultimately allowing the fuel to achieve high combustion efficiency. Volume ignition is the use of energy balance relations under the local thermodynamic equilibrium approximation to establish the energy balance equation for thermonuclear systems, and the system ignition threshold is obtained by solving this equation. By understanding the physical process, we believe that the non-equilibrium process is universal to the volume ignition process. Changes in external factors (density, boundaries, albedo, etc.) at the moment of ignition can have a significant impact on the development direction of the system, and an ignition system with a large surface density can nevertheless withstand a large amount of reverse work and continue to burn. The design of the ignition target tries to avoid these factors through margin design, but conversely, the rational use of these laws can further improve the design margin of the capsule. With the aid of big data, the volume ignition method is easier to calculate and has a shorter iteration time. The traditional way is to propose a model, set the material, and then perform the calculation while using big data can set any model and material for calculation. In this paper, a simple comparison will be made to find out that the efficiency of the physical design of a volume ignition target will be effectively improved with the aid of big data. Volume ignition targets can be used not only in Z-pinch-driven systems but also for laser-driven volume ignition.
Mechanism of Bubble Point Pressure and Gas-oil Ratio Changing with Depth in Complex Structural Reservoirs
Authors: Jing Wenlong , Li Aifen , Cheng Yulong
Published: December 2022

Reservoir bubble point pressure and gas-oil ratio are important parameters for the scheme design of oilfield development and calculation for reservoir elastic reserves. However, their change laws are complex. At present, there are few studies on the mechanism of bubble point pressure and gas oil ratio changing with depth, which is an urgent problem to be solved in the exploration and development of oil and gas fields. This study focuses on the variation mechanism of bubble point pressure and gas-oil ratio with depth under different tectonic movement conditions in the process of reservoir formation of complex structural reservoirs. When the buried depth of the reservoir is small, the crude oil from bottom to top will be in an unsaturated state (bubble point pressure is less than the formation pressure) to a saturated state (bubble point pressure is greater than the formation pressure), and there will be a gas cap at the top of the oil layer. When the buried depth of the reservoir is large, the formation pressure of the reservoir from bottom to top is greater than the bubble point pressure, and the crude oil of the reservoir is in a single-phase state. A series of tectonic movements will occur in the process of reservoir formation of complex structural reservoirs, which will affect the state of oil and gas in the reservoir. In this study, under the three conditions of complex structural reservoirs including no tectonic movement, tectonic uplift, and tectonic subsidence, the change in bubble point pressure and gas-oil ratio with depth was analyzed respectively. Finally, the mechanism of bubble point pressure and gas-oil ratio changing with depth in complex structural reservoirs is obtained. This study can provide theoretical guidance for reservoir reserve research and development scheme design.
Research on the accuracy of the generalized Lévy’s solution for deflection of open cylindrical shell structures
Authors: Wang Zhaodong , Li Zhong , Li Pu
Published: December 2022

In the last century, the plate and shell theory has been developed and matured through the research of many theoretical workers at home and abroad. The generalized Lévy’s solution can be used to obtain the static response of a semi-cylindrical shell with curved ends simply supported under arbitrary load. However, the solution is complex and difficult to calculate, so on this basis, a series of simplified methods under specific working conditions are developed, such as the moment-free theory and semi-moment-free theory of cylindrical shells. In this paper, MATLAB will be used to calculate the generalized Levi’s solution and semi-moment-free theory, and compare them with the finite element results of ANSYS. Finally, it is found that the two theoretical solutions can only roughly predict the distribution form of displacement, with an order of magnitude difference. The engineering significance is limited, and the results still need to be improved.
Tension and Deformation Analysis of Suspension Cable of Flexible Photovoltaic Support under Concentrated Load with Small Rise-span Ratio
Authors: Jiang Fangxin , Shang Renjie , Sun Yue
Published: December 2022

The suspension cable structure with a small rise-span ratio (less than 1/30) is adopted in the flexible photovoltaic support, and it has strong geometric nonlinearity. Based on the principle of energy, the increment of cable force and the change of cable displacement under concentrated force are derived for the suspension cable in an equilibrium state under uniform distributed load, and the equivalent bending stiffness of simply supported beam under bending is given. Considering the strain energy generated by cable force variation, the method presented in the paper has higher calculation accuracy for suspension cable structures with a small rise-span ratio, and includes the special case of a large rise-span ratio. An engineering example of flexible photovoltaic support with a span of 15m is calculated and analyzed, and then compared with the finite element calculation results. The results show that the calculation error is less than 1% when the rise is 0.4 m, and the calculation error is less than 3% when the rise is 1.5m. The calculation formula in the paper is simple and accurate, which can provide a reference for static analysis and structural design of flexible photovoltaic support.
Enlightening Visualization of Charge on Capacitors and Capacitor Circuits
Authors: Xuan Chen
Published: December 2022

The ideal parallel plate capacitor in general physics textbooks lacks electrostatic perspectives regarding how conducting surfaces are charged. The current textbooks somewhat neglect close connections between capacitors and electrostatics, leaving students in limbo when analyzing charge distribution on capacitors in circuits. This paper will suggest a new generalized model of the ideal capacitor and offer learners, mainly from the electrostatic perspective, a better train of thought in analyzing how charges are distributed on various surfaces in capacitor circuits. This paper offers a relatively complete review and framework of the ideal capacitor and can serve as supplementary reading material for general physics learners and instructors for in-depth explanations of fundamental topics unavailable in the current textbooks.
Dielectric Condensers: Gauss’ Law and New Visualizations under Macro-and Microscopic Representations
Authors: Xuan Chen
Published: December 2022

The ideal condenser with dielectric in general physics is delivered in a way that lacks in-depth explanation, leaving students in limbo when asked to explain how different surfaces on dielectric condensers when connected/disconnected with wires are charged. This paper will offer a relatively complete set of multiscale tutorials on different methods of applying Gauss’ law on condensers with a dielectric as well as a technique of abstracting condensers partially inserted with dielectric into parallel and series condenser models, both with an emphasis on how to better visualize different surfaces carrying charges of different origins. Special attention in this paper is paid to the best visualization to explain such concepts on different scales. This paper offers a relatively complete review and framework of ideal condensers with dielectric, 1st proposed, which can serve as supplementary reading material for general physics learners and instructors for in-depth explanations or alternative perspectives on fundamental topics unavailable in textbooks.
Introduction to the Decay of Common Particles
Authors: Yang Zitao
Published: December 2022

One of the most important scientific research results in decades is the discovery of a boson particle that has the properties of the Higgs boson, which reiterates the importance of studying particle decay. In this paper, an introduction to common particle decays is given. It contains theoretical and experimental information. On the theoretical side, the paper discusses the concept of decay rate and branching fraction and dives into specific particle decays—the decays of the muon, neutral pion, and neutron. The theoretical results are then correspondingly compared with experimental results. The last section on the decay of the Higgs boson takes an experimental perspective, exploring the details of the data produced at the Large Hadron Collider (LHC).
21 cm Radio Wave Observation on the Milky Way Rotation Curve
Authors: Chen Zhekai
Published: December 2022

Nowadays, the scientific community has generally accepted the existence of dark matter. Astrophysicists investigate this assumption by astronomical observation. The galaxy rotation curve is one of the pieces of evidence for dark matter’s existence. The TLM18 telescope detects a 21 cm radio wave from the Milky Way to measure the rotation curve of the Milky Way. This article analyzes the frequency-power data to find out the rotation curve of the galaxy. The rotation curve is compared to existing theories, including the Kepler model, the exponential disk model, and the isothermal dark matter halo. Combining the exponential disk model with the isothermal dark matter halo, the calculation fits well with observation.
The Derivation of Elastic Fields of a Curvilinear Inclusion
Authors: Lee Yonggang
Published: December 2022

The disturbed elastic fields of a curvilinear inclusion in an isotropic elastic plane are investigated analytically by a newly proposed technique. The boundary of the inclusion is characterized by arbitrary Laurent polynomials in the 2D Cartesian coordinate system, and constant eigenstrains are considered to occur in the inclusion. Based on the irreducible decomposition of an arbitrary tensor, the Eshelby tensor is attributed to two integrals on the curved boundary of the inclusion. The analytical solutions for the induced stress and displacement fields outside the inclusion domain are explicitly derived by utilizing the newly developed technique, including the salient features of the Faber polynomials. Examples show the efficiency of the technique in this paper.
Experimental Study on Damage of the Rail/wheel Sliding Contact Surface in Heavy-haul Railway
Authors: Wei Yunpeng , Wu Yaping
Published: December 2022

Heavy-haul railway plays very important roles in transportation of bulk goods because of their special advantages. Heavy-haul trains can cause obvious damage to the rail/wheel contact surface when starting or braking. In this paper, a new rail/wheel friction testing machine is designed and built, and the damage characteristics of the contact surface during rail/wheel sliding contact are studied. The experimental results show in the process of sliding contact, a large amount of grooves can be seen on the wheel surface and are becoming more obvious with the increase of loads and speeds. On the rail surface, there are various types of damages, including adhesion, spalling, grooves, corrosion, etc., which are closely related to cracks. The results also indicate the wheel wear amount gradually increases with the growth of loads and speeds. However, the rail wear amount varies greatly, which is related to the adhesion of wear particles.
Study on Improvement of Pipe-Soil Spring Model in Mountain Slope Area
Authors: Wang Dongyuan
Published: December 2022

For the interaction between the pipeline and the soil under the condition of large surface displacement, the displacement load is often transmitted to the pipeline through soil springs. The selection of soil spring parameters is based on laboratory research results, which may not be effective for pipe-soil interface simulation. In addition, the load and soil spring coefficient of the pipeline in the slope should vary with space and time, and these factors are ignored by the resistance formula of the current general spring model. The adaptability and temporal load distribution of the pipe-soil spring model in regions of large surface deformation are largely unknown. In this paper, we deduced the soil spring resistance formula when the surface is inclined, established an improved soil spring model for the slope, and obtained the variation law of soil spring resistance in different directions at different slope angles. At the same time, a comparison of the improved soil spring model with the standard soil spring model recommended by international associations and codes was carried out. The rationality of the improved soil spring model proposed in this paper in the calculation of the pipe-soil interaction in the slope section is further verified by small-scale physical model tests. It has a certain guiding significance for the calculation of pipe-soil interaction in slope sections.
Study on Strength Failure and Optimization Scheme of Steel Platform Anti-Skid Strip
Authors: Shen Xuejing , Wang Meili , Yu Shuang , Wang Deshan
Published: December 2022

The strength failure of the anti-skid strip is one of the key factors restricting the service efficiency of the steel platform. In this paper, the compressive stress, shear stress, and the stress on the weld of the steel platform anti-skid strip during the movement of tracked vehicles are obtained through the movement mechanics analysis of heavy tracked vehicles, and the corresponding strength failure conditions are established. According to the calculation results, improvement measures and schemes are proposed for the layout spacing and size of the anti-skid strips on the mechanized platform, to improve the anti-skid and wear-resistant performance of the platform plate.
Sensitivity Analysis of One-Dimensional Performance Prediction for Centrifugal Compressor
Authors: Tang Yaoxuan , Zhang Xi , Liu Yanming , Wang Dalei
Published: December 2022

To explore the sensitivity sorting of a one-dimensional performance prediction model, a high-load centrifugal compressor is studied. Using the Latin Hypercube method, the influencing factors of the one-dimensional performance prediction model are designed. Based on the sensitivity analysis of ANOVA, the main influencing factors of compressor pressure ratio and efficiency performance are investigated, and guidance for compressor optimization is proposed. The results show that the main factors affecting the pressure ratio are deviation loss, radial diffuser incidence loss, and impeller blockage loss. The main factors affecting the efficiency are radial diffuser incidence loss, radial diffuser blockage loss, and radial diffuser choke loss. Finally, the optimal coefficients corresponding to the loss models are obtained based on the sensitivity sorting results. Compared with the corresponding three-dimensional numerical simulation, the error of pressure ratio and efficiency near the design condition is within 1%, which indicates that the presented method can achieve the accurate design and off-design performance prediction.
The Significance of Cyclic Groups
Authors: Wen Hanlei
Published: December 2022

Investigation in group theory has been a widespread practice within the realm of mathematics. In finite group theory specifically, mathematicians have historically aimed to classify finite simple groups. Following the turning consensus that the finite simple group classification is complete, research within finite group theory has shifted to other areas. However, this paper endeavors to fill the missing gaps in the current classification – it does not specify the importance of finite group theory. By focusing on introducing, explaining, and demonstrating cyclic groups and their applications, the paper will reveal, specifically, the importance of cyclic groups in the realm of mathematics and beyond. In particular, the qualities of finite cyclic groups allow them to apply easily and broadly from as simple as division rules and binary number systems (by use of a set of integers of modulus n), to more advanced theory and implementation with computer science. Cyclic group theory deserves increased recognition. In addition, by providing definitions, evaluations, proofs, and concrete examples, this paper also endeavors to become a point of reference for readers to understand, consolidate, and further grasp cyclic group theory and its uses.
Effect of Perlite Content on Performance of Emulsion Explosive in Under-Water Environment
Authors: Liu Lei , Qi Hongyu , Zhang Haitao , Qi Jixing
Published: December 2022

Emulsion explosive has been widely used in underwater blasting construction. To study the effect of perlite content on the performance of emulsion explosives under deep water conditions, the performance of emulsion explosives with different applied pressures and different perlite contents was studied by using the self-built underwater explosion test system. The results show that, with the increase of pressure in the water, the energy of emulsion explosive with different content of perlite as sensitizer has a decreasing trend, which is consistent with the actual situation, and when the perlite content is 4%, the sensitized bubble is adiabatically compressed, and the hot spot fully explodes, and its detonation performance is the best.
Risk Prediction of Gasifier System Based on Dynamic Cloud Bayesian Network
Authors: Liu Ming , Zhou Yan , Sun Lin
Published: December 2022

To address the current problem of insufficient risk level analysis of gasifier systems, an evaluation method combining the cloud model and dynamic Bayesian network is proposed, taking the gasifier system as the evaluation target, using the cloud model to discretize continuous data, and setting each risk factor in the evaluation system as a node in the dynamic Bayesian network to build a dynamic Bayesian network. The entropy weight method is used to calculate the weight of each risk indicator, the maximum likelihood estimation method is used to process the affiliation degree obtained from the cloud model, and the probability obtained by the affiliation-probability conversion method is input into the dynamic Bayesian network as evidence. Finally, the risk prediction assessment for the gasifier system is completed by using the features of forwarding and backward inference of the dynamic Bayesian network, combined with the comprehensive analysis of importance. The study shows that human maintenance efficiency, equipment integrity, gasifier pressure, and oxygen-coal ratio are the weak points that need to be focused on in the operation of the system.
Construction Technology of Pretension Prestressed Reinforced Concrete Structure of Multi-storey Logistics Warehouse
Authors: Wu Qinggang , Zhang Xianjun , Ma Jihao , Lv Xiangyang , Zhang Baoxin , Rong Jianchao
Published: December 2022

At present, there is a problem of too much prestress loss in the construction of multi-layer logistics warehouses in China. To meet the quality requirements of the project, this paper puts forward the research on the construction technology of pretension prestressed reinforced concrete structure of multi-layer logistics warehouse. The loss of prestress in the construction process can be effectively controlled by incorporating pre-tensioning technology into the construction process, placing prestressed tendons, and tensioning operations. Taking a logistics warehouse construction project as the construction object, using the construction technology designed in this paper to construct, the experiment proves that the construction technology of the pretension prestressed reinforced concrete structure of the multi-layer logistics warehouse proposed in this paper can effectively reduce the prestress loss caused by the instability of the construction structure, and can effectively improve the construction quality of the multi-layer logistics warehouse. This shows that the application and practice of pretension prestressing technology in the construction process of reinforced concrete structures has a positive reference significance, which can meet the needs of green engineering such as energy saving and emission reduction, and also provide a positive reference value for the construction technology of multi-layer logistics warehouse.
Research on RCS Jet Interaction Characteristics of the Capsule Entry Vehicle at Subsonic and Transonic Speed
Authors: Zhang Jiayue , Ma Jikui , Liu Yaofeng
Published: December 2022

In this paper, the RCS jet interaction characteristics of the capsule entry vehicle were studied by numerical simulation. The jet interference characteristics under different re-entry ballistic parameters were compared. The influence of the angle of attack on the jet flow field structure and aerodynamic characteristics was analyzed.
Study on the influence of artillery recoil on the lateral stability of patrol boat
Authors: Zheng Xiaolong , Jiao Jun , Li Chenghua
Published: December 2022

To solve the problem of lateral instability of a high-speed law enforcement patrol boat caused by the recoil of artillery fire, this paper adopts the method based on EFD (Experiment Fluid Dynamics), the dynamic stability of a high-speed patrol boat model under the impact of an external force is simulated by a percussive test. First, the model of the patrol boat is tested by dragging on the surface of still water, and then the percussive test is carried out with different centers of gravity height, different external impulses, and different speeds, the influence of the above factors on the transverse stability of patrol boat is studied. The results show that the higher the height of the center of gravity, the higher the external impulse and the lower the speed, the worse the transverse stability of the model will be. The results show that the EFD method is feasible, which is of great significance to the shape optimization design of high-speed craft and the selection of artillery systems.
An Optimization of COVID-19 Vaccine Distribution in Canada Based on the VRP Model
Authors: Yuan Ruoxi
Published: December 2022

SARS-Cov-2, or COVID-19, is a new emergent human-transmitting disease, which has caused a worldwide pandemic crisis affecting every aspect of our life. With the latest medical enhancements, vaccines from numerous medical companies (Pfizer, Moderna, Sinovac, etc.) have been proven effective in controlling the hospitalization and deaths caused by COVID-19. Cold-chain transportation of vaccines is a crucial part of providing vaccination. The standard procedure is to store vaccines at low temperatures, around 2°C to 8°C, during any time of transportation. However, due to the uncertainty in this process, a well-developed, monitored cold-chain logistics network is demanded. This paper explores the optimization of the contributing factors, involving data analysis and applied mathematical models, focusing on a case study of the Ontario, Canada area. The simulated results provide a general concept and indication for the administrators and regulators to design and achieve a suitable and fair distribution of vaccines.
A Prediction Method of Ship Traffic Accidents Based on Grey GM(1,1) Model
Authors: Wang Ze , Xu Shiyuan
Published: December 2022

In order to improve the inaccuracy of the GM(1,1) model in the prediction of ship traffic accidents caused by large data fluctuations, a weighted average weakening buffer operator is applied to the GM(1,1) residual error correction model to improve the prediction accuracy. This method is based on the modeling principle of the GM(1,1) residual error correction model. Firstly, GM(1,1) model is established based on the original data sequence to obtain the simulated value, predicted value, and residual tail sequence. Then, the residual tail sequence of the oscillation fluctuation is processed by positive value and weighted average weakening buffer operator, so as to establish the residual GM(1,1) model and correct the original prediction value with the residual prediction value; Finally, this method is applied to the prediction of British merchant shipping traffic accidents to verify its effectiveness. The results show that this method has high prediction accuracy in the short-term prediction of ship traffic accidents.
The Prediction Model of IPIX Radar Sea Clutter Based on SSA-ELM Neural Network
Authors: Zhou Ke , Xi Caiping , Yang Yunfan
Published: December 2022

The prerequisite for improving radar detection capability is to reduction of sea clutter from interfering with the target, and the accurate prediction of sea clutter is an essential prerequisite for effective suppression. To achieve an accurate prediction of sea clutter, a model for sea clutter prediction combination of the salp’s swarm algorithm, prediction using extreme learning machine after performing parameter search, which improves the prediction performance of ELM and backpropagation (BP) neural network. The convergence speed and accuracy are improved, and the overall prediction The IPIX radar sea clutter prediction reaches an accuracy of more than 99% and the prediction results of this model are better than that when only using ELM or BP neural network prediction.
Thermal Rectification in the Coaxial Carbon Nanotube@boron Nitride Nanotube Composite
Authors: Huang Haibo , Huang Xiaohua , Meng Xianguo , Cheng Zaijun
Published: December 2022

To control and utilize thermal energy more precisely, an asymmetric thermal rectifier is designed in this paper. Through molecular dynamics calculations, it is found that the device has obvious thermal rectification phenomenon. The equivalent thermal conductivity of the device increases gradually with temperature. The thermal rectification coefficients at different temperatures are calculated, and it is found that the thermal rectification coefficients fluctuated wildly with temperature. The temperature distribution map inside the device and the fact that the thermal conductivity of the device increases with temperature indicate that the asymmetry of radial heat transfer and the interlayer coupling determine this thermal rectification property.
Corrosion of steel materials in four environmental conditions
Authors: Wang Jiayu , Liu Peng , Ren Kaixu , Wang Xin , Xu Shujie
Published: December 2022

The corrosion of metal materials greatly affects the life of the equipment. Focusing on four typical environmental conditions, this paper takes steel material as the research object and analyzes the influence of factors (temperature, humidity, SO2, Cl− and others) on the corrosion rate of steel materials, as well as the weight loss and morphology. The results show that the atmospheric corrosion rate is 5.88-30.78 μm/A, and increases by 185% on average with the increase of Cl− concentration under road salt conditions. The static and dynamic corrosion rates show a three-step distribution. The concentration of chemical media in the liquid film accumulates, and the synergistic corrosion of multiple factors makes the corrosion rate much higher than the atmospheric corrosion intensity. The maximum corrosion rate under the static condition is the low latitude coastal condition (386 μm/a), and the dynamic working condition is the high latitude coastal working condition (85.6 μm/a).
The Performance and Application of High-temperature Functional Coatings
Authors: Yang Junhua , Wang Wei , Lu Yang , Zhu Lizhi , Yang Chunxia , Wang Qiang
Published: December 2022

A radar component is made of high-temperature-resistant composite materials. For long-term use at a temperature of 200°C, and to withstand certain temperature impacts, it should have a dielectric constant that is not greater than 3.5 at a certain frequency, a dielectric loss not greater than 0.03, an emissivity not greater than 0.085, and a thickness of no more than 0.15 mm. Aiming at the requirements, the properties of three kinds of organosilicon-modified coating systems were studied, and the optimal coating system that meets the needs of radar are selected. According to the actual situation of the component and the characteristics of the selected coating system, the construction process of the rapid volatilization coating was completed. The coating has effectively resisted the high-temperature effect and played a functional role, providing reliable technical support for the development of the radar.
Effect of Single and Double Pulse MIG Welding Process Parameters on Microstructure and Properties of Aluminium Alloy
Authors: Li Lin , Cao Yuhua , Fen Tiantian , Lv Chang
Published: December 2022

Lightweight aluminium alloys are widely used in many industries due to their advantageous mechanical properties. As welding is a popular method for joining aluminium alloy sheets, it is important to understand how the welding process affects the alloy’s performance. Here, we investigated the influence of various operating parameters during pulsed metal inert gas (MIG) welding of thin aluminium alloy plates on the input energy and metallurgical microstructure of the weld. A series of welding tests were performed using surface welding of AA6061 aluminium alloy plates under conditions of a single strong-pulse, single weak-pulse, or double pulse. The morphology, metallurgical structure, and hardness of the welds produced using the different welding parameters were then examined. We observed that increasing the welding speed and the arc duration of low-energy pulses can reduce the heat input. Lower heat input is advantageous as it results in a higher cooling rate of the welding pool and a smaller average grain size of the weld structure. In addition, increasing the welding speed increased the hardness of the weld. Double pulsed MIG welding showed the best overall weld performance and is recommended for improving the quality of aluminium alloy bonding.
Preparation and Properties of Trivalent Chromium/Zirconate Composite Conversion Coating on Al-50%Si Alloy
Authors: Wu Liqun , Guo Ruiguang , Yin Shihua
Published: December 2022

Al-50%Si alloy is a mainstream electronic packaging material. In order to solve the problem of high corrosion resistance on the surface of Al-50%Si alloy and reduce environmental pollution, a trivalent chromium/zirconium salt composite conversion coating was developed for the package shell without acid-base washing and spraying. The appearance, surface morphology, composition, and corrosion resistance of the conversion coating were characterized and analyzed by visual inspection, scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and neutral salt spray test. The results show that the prepared trivalent chromium/zirconium salt composite conversion coating is composed of amorphous particles. After treatment, the content of Zr element on the surface of Al-50%Si alloy increases to 3.63%, Cr element increases to 0.82%, and oxygen content increases to 9.21%; after 168 hours of neutral salt spray test, there is no obvious corrosion on the surface of the conversion coating.
Study on environmental corrosion performance of hot dip galvanizing coating
Authors: Liu Hongyu , Liu Jianing , Fu Jia , Zhao Jian , Sun Zhonghua , Huang Weichang , Su Yunhai
Published: December 2022

In order to analyze the influence of environmental factors on the corrosion resistance of hot-dip galvanized coating, a naturally clean environment and thermal shock treatment were used to simulate the service conditions of products. The surface state and zinc layer thickness of hot-dip galvanized coating under two process conditions were detected. Salt spray corrosion and electrochemical corrosion tests were carried out on hot-dip galvanized coatings. The phase and microstructure of the coating were analyzed by XRD, OM, and SEM. The results show that the hot-dip galvanized coating has a good corrosion protection effect in a naturally clean environment. After thermal shock treatment, cracks in the coating are more likely to occur. With the increase of thermal shock time, the depth of crack on the surface of the coating increases, so the corrosion protection effect of the coating decreases obviously. For the thermal shock treatment of 10-30 days, the coating performance enters the corrosion stability period, and the thickness decreases very little, but when the time exceeds 30 days, the corrosion of the coating accelerates sharply. Electrochemical corrosion shows that the hot-dip galvanized coating has typical coating protection double capacitive reactance curve, and the polar protection effect is good. When the thermal shock treatment time is 30 days, the dense oxide on the coating surface has the best protection effect against corrosion. At this time, the self corrosion current is the smallest and the impedance radius is the largest. When the thermal shock treatment time exceeds 40 days, the cracks on the coating surface will expand to the substrate, and the corrosion protection effect of the coating may fail. So, the corrosion protection effect of hot-dip galvanized coating is limited in the current situation of frequent extreme environments and intensified environmental pollution.