Research on the Resistance of Cutting Mechanism of Mining Longitudinal Roadheader

In order to accurately obtain the dynamic characteristics of the cutting mechanism of the mining longitudinal roadheader,combined with the working principle of the mining longitudinal roadheader,the theoretical analysis and derivation are carried out in detail.By using ADAMS to simulate,the resistance curve and torque curve of the cutting mechanism in different directions are obtained.The results show that ADAMS can effectively predict the excavation resistance and torque of the cutting mechanism of mining longitudinal roadheader,which has certain reference value for future optimization design.

An Improved Harris Hawk Optimization Algorithm

Aiming at the problems that the original Harris Hawk optimization algorithm is easy to fall into local optimum and slow in finding the optimum,this paper proposes an improved Harris Hawk optimization algorithm(GHHO).Firstly,we used a Gaussian chaotic mapping strategy to initialize the positions of individuals in the population,which enriches the initial individual species characteristics.Secondly,by optimizing the energy parameter and introducing the cosine strategy,the algorithm's ability to jump out of the local optimum is enhanced,which improves the performance of the algorithm.Finally,comparison experiments with other intelligent algorithms were conducted on 13 classical test function sets.The results show that GHHO has better performance in all aspects compared to other optimization algorithms.The improved algorithm is more suitable for generalization to real optimization problems.

Design a Special Fixture for Tractor Lever

Aiming at the problems of long time and poor machining precision in processing the tractor lever workpiece,a special fixture suitable for the tractor lever workpiece is designed by analyzing the processing technology of the lever workpiece,and the workpiece is accurately positioned and tightened under the action of the special fixture.Efficient machining of the workpiece can be achieved by using a drill template.The fixture not only has the advantages of high production efficiency,low cost and high life,but also effectively improves the processing technology of the workpiece,and has certain reference value for the subsequent fixture improvement design.

Coronavirus Mask Protection Algorithm:A New Bio-inspired Optimization Algorithm and Its Applications

Nowadays,meta-heuristic algorithms are attracting widespread interest in solving high-dimensional nonlinear optimization problems.In this paper,a COVID-19 prevention-inspired bionic optimization algorithm,named Coronavirus Mask Protection Algorithm(CMPA),is proposed based on the virus transmission of COVID-19.The main inspiration for the CMPA originated from human self-protection behavior against COVID-19.In CMPA,the process of infection and immunity consists of three phases,including the infection stage,diffusion stage,and immune stage.Notably,wearing masks correctly and safe social distancing are two essential factors for humans to protect themselves,which are similar to the exploration and exploitation in optimization algorithms.This study simulates the self-protection behavior mathematically and offers an optimization algorithm.The performance of the proposed CMPA is evaluated and compared to other state-of-the-art metaheuristic optimizers using benchmark functions,CEC2020 suite problems,and three truss design problems.The statistical results demonstrate that the CMPA is more competitive among these state-of-the-art algorithms.Further,the CMPA is performed to identify the parameters of the main girder of a gantry crane.Results show that the mass and deflection of the main girder can be improved by 16.44%and 7.49%,respectively.

Multidisciplinary co-design optimization of structural and control parameters for bucket wheel reclaimer

Bucket wheel reclaimer(BWR)is an extremely complex engineering machine that involves multiple disciplines,such as structure,dynamics,and electromechanics.The conventional design strategy,namely,sequential strategy,is structural design followed by control optimization.However,the global optimal solution is difficult to achieve because of the discoordination of structural and control parameters.The co-design strategy is explored to address the aforementioned problem by combining the structural and control system design based on simultaneous dynamic optimization approach.The radial basis function model is applied for the planning of the rotation speed considering the relationships of subsystems to minimize the energy consumption per volume.Co-design strategy is implemented to resolve the optimization problem,and numerical results are compared with those of sequential strategy.The dynamic response of the BWR is also analyzed with different optimization strategies to evaluate the advantages of the strategies.Results indicate that co-design strategy not only can reduce the energy consumption of the BWR but also can achieve a smaller vibration amplitude than the sequential strategy.

Hypoxia-induced GBE1 expression promotes tumor progression through metabolic reprogramming in lung adenocarcinoma

Hypoxia mediates a metabolic switch from oxidative phosphorylation to glycolysis and increases glycogen synthesis.We previously found that glycogen branching enzyme(GBE1)is downstream of the hypoxia-inducible factor-1(HIF1)signaling pathway in lung adenocarcinoma(LUAD)cells;however,the molecular mechanism underlying HIF1 regulation of GBE1 expression remains unknown.Herein,the effect of GBE1 on tumor progression via changes in metabolic signaling under hypoxia in vitro and in vivo was evaluated,and GBE1-related genes from human specimens and data sets were analyzed.Hypoxia induced GBE1 upregulation in LUAD cells.GBE1-knockdown A549 cells showed impaired cell proliferation,clone formation,cell migration and invasion,angiogenesis,tumor growth,and metastasis.GBE1 mediated the metabolic reprogramming of LUAD cells.The expression of gluconeogenesis pathway molecules,especially fructose-1,6-bisphosphatase(FBP1),was markedly higher in shGBE1 A549 cells than it was in the control cells.FBP1 inhibited the tumor progression of LUAD.GBE1-mediated FBP1 suppression via promoter methylation enhanced HIF1αlevels through NF-κB signaling.GBE1 may be a negative prognostic biomarker for LUAD patients.Altogether,hypoxia-induced HIF1αmediated GBE1 upregulation,suppressing FBP1 expression by promoter methylation via NF-κB signaling in LUAD cells.FBP1 blockade upregulated HIF1α,triggered the switch to anaerobic glycolysis,and enhanced glucose uptake.Therefore,targeting HIF1α/GBE1/NF-κB/FBP1 signaling may be a potential therapeutic strategy for LUAD.