Curriculum Reform of Higher Vocational Mathematics Under the Background of Digital Transformation

Under the background of digital transformation,the reform of the higher vocational mathematics curriculum faces urgent challenges and opportunities.This article explores the impact of digital transformation on the reform of higher vocational mathematics curriculum and emphasizes the importance of improving teaching methods centered on learners.The article proposes specific reform methods and discusses the practical application of digital technology in the reform process.By combining digital technology with specific reform methods,further conducting innovative practice research,and continuously exploring the path of reform,we can effectively improve the quality of higher vocational mathematics classroom teaching and provide strong support for the cultivation of comprehensive qualities and employment abilities.

Optimization of Animal-Glue Binders for Casting Applications

In typical metal foundry applications,sand casting is still the most used technology.The related binder plays a very important role as its performances can directly influence the quality of castings.Among many binders,glues of animal origin have attracted much attention in recent years due to their reduced environmental impact.How-ever,they display some drawbacks such as the tendency to coagulate easily at room temperature and a relatively low strength.In this study,a novel gas-hardening casting binder was prepared using an animal glue and anhy-drous potassium carbonate as a hydrolyzing agent to avoid undesired agglomeration.Moreover,sodium pyropho-sphate and furfuryl alcohol were exploited as modifiers to obtain a binder with a high compressive strength.The best modification conditions,determined by means of an orthogonal design matrix approach,were 4 g of Na2CO3,sodium pyrophosphate,furfuryl alcohol and animal glue with a ratio of 4:12:100,at 85°C and with a duration of 115 min,respectively.The viscosity of the mixture obtained under these optimized conditions was 1250 mPa⋅s.The compressive strength of the binder,hardened by CO_(2) gas,was 4.00 MPa.Its gas evolution at 850°C was 15 ml⋅g-1,and its residual strength after 10 min calculation at 800°C was 0.01 MPa,which is high enough to meet the requirement of core-making in foundry.Moreover,after hydrolysis and further modification,animal glue and modifiers displayed a grafting reaction and an esterification reaction,respectively,which made the adhesive network denser and improved its thermal stability.

Protective effect of compressing arc extinguishing lightning protection device on superimposed lightning strikes

Traditional lightning protection measures can not solve the problem of superimposed lightning strikes.This paper presents a compressing arc extinguishing lightning protection device,which can solve the problem of superimposed lightning strikes.This device can extinguish the power frequency continuous current arc quickly in 1-2 ms.It is far less than the response time of relay protection,which can avoid lightning trips and improve the reliability of power supply.The computer simulation and engineering practice show that the compressing arc extinguishing device has good protection effect on superimposed lightning strikes.

Research on Teaching Method of Children’s Image Cognition Based on AR Technology

In this paper,the research on the teaching method of children’s image cognition based on AR technology is carried out.By analyzing the principle ofARtechnology to recognize images,we understand thatARtechnology can promote children’s image cognition,and this teaching method is in line with the Tower of Experience theory.It further analyzes the current situation of children’s image cognition teaching with simple teaching methods,backward AR teaching tools,and poor perception of teaching objects.Teachers’traditional image teaching methods cannot effectively and efficiently improve children’s image cognition.Therefore,based on AR technology,two commonly used image cognition teaching methods are proposed:AR interactive picture book education andARinteractive game education.Both of these educational methods can improve children’s ability to recognize images.

Synthesis of titanium carbide coating on Ti15Mo alloy and its tribological behaviour

Ti15Mo alloy has been regarded as one of the most potential biomedical materials due to its excellent performance.However,the low hardness and poor wear resistance of titanium alloy limit the further application.Therefore,high temperature solid carburising technology was performed on the surface of Ti15Mo alloys to prepare titanium carbide(TiC)coating with graphene(G)as the carburising agent.The microstructure,mechanical properties,and tribological properties of TiC coating under different lubricants were investigated.Results showed that TiC coating was closely bonded to the titanium substrate.The maximum thickness of TiC coating treated with 1150°C was approximately 184.02μm,and the microhardness of alloys treated with 1100°C can achieve 1221.5 HV.All modified Ti15Mo alloys showed improved tribological performance compared to the original samples.The wear mechanisms of modified Ti15Mo alloys were abrasive wear and adhesive wear under the SBF lubricant,and the TiC coating was slightly peeled off.The overall friction coefficient and wear rate under 25%calf serum lubricant were lower than the SBF lubricant,and surface scratches were almost absent,and slight abrasive wear and adhesive wear occurred on the surface.

Qualitative analysis of a diffusive predator–prey model with Allee and fear effects

In this study,we consider a diffusive predator-prey model with multiple Allee effects induced by fear factors.We investigate the existence,boundedness and permanence of the solution of the system.We also discuss the existence and non-existence of non-constant solutions.We derive sufficient conditions for spatially homogeneous(non-homogenous)Hopf bifurcation and steady state bifurcation.Theoretical and numerical simulations show that strong Allee effect and fear effect have great effect on the dynamics of system.

Tribo-corrosion mechanisms and electromechanical behaviours for metal implants materials of CoCrMo,Ti6Al4V and Ti15Mo alloys

Corrosion and wear play significant roles in the aseptic loosening of artificial hip joints for the long-term service.In this present study,tribo-corrosion tests were carried out through a reciprocating ball-on-plate system to evaluate the corrosion and wear prop-erties of CoCrMo,Ti6Al4V and Ti15Mo alloys in a simulated body fluid(SBF)solution.It was found that the tribo-corrosion behaviours of CoCrMo/Al_(2)O_(3)and Ti15Mo/Al_(2)O_(3)systems had significant wear-corrosion synergistic interaction,and wear-induced corro-sion was dominant.For Ti6Al4V/Al_(2)O_(3)systems,their wear mechanism under SBF lubrication was a combination of abrasive,adhesive and fatigue wear.While the wear mechanism of the Ti15Mo/Al_(2)O_(3)system under synergistic interaction was a combination of abrasive and adhesive wear.Finally,it was suggested that the Ti15Mo alloy would be the better alternative for metal implant applications compared with the CoCrMo alloy for the consideration of both wear and potential poisonous ions such as Co(III)and Cr(VI).