Numerical simulation research of dimension variation in heavy plate during quenching and tempering process

The dimension variation of B610E steel during the quenching and tempering process was simulated by ABAQUS,the coefficient of heat transfer during quenching was verified by the buried thermocouple test and the trend of the dimension variation during the quenching process was also calculated by ABAQUS. It was shown by the comparison of simulated results and industrially measured results that only the simulation of thickness and width variation was accurate, while length variation needed further simulation. Besides, the dimension variation trend was identical with the measured results.

An improved four-dimensional variation source term inversion model with observation error regularization

Aiming at the Four-Dimensional Variation source term inversion algorithm proposed earlier,the observation error regularization factor is introduced to improve the prediction accuracy of the diffusion model,and an improved Four-Dimensional Variation source term inversion algorithm with observation error regularization(OER-4DVAR STI model)is formed.Firstly,by constructing the inversion process and basic model of OER-4DVAR STI model,its basic principle and logical structure are studied.Secondly,the observation error regularization factor estimation method based on Bayesian optimization is proposed,and the error factor is separated and optimized by two parameters:error statistical time and deviation degree.Finally,the scientific,feasible and advanced nature of the OER-4DVAR STI model are verified by numerical simulation and tracer test data.The experimental results show that OER-4DVAR STI model can better reverse calculate the hazard source term information under the conditions of high atmospheric stability and flat underlying surface.Compared with the previous inversion algorithm,the source intensity estimation accuracy of OER-4DVAR STI model is improved by about 46.97%,and the source location estimation accuracy is improved by about 26.72%.

DIMENSION VARIATION OF FEATURE-BASED MODEL BY OPERATING DIRECTLY ON B-REP

ＤＩＭＥＮＳＩＯＮＶＡＲＩＡＴＩＯＮＯＦＦＥＡＴＵＲＥ┐ＢＡＳＥＤＭＯＤＥＬＢＹＯＰＥＲＡＴＩＮＧＤＩＲＥＣＴＬＹＯＮＢ┐ＲＥＰＨＥＸｉａｏｚｈａｏ（何小朝），ＷＡＮＧＺｏｎｇｙａｎ（王宗彦）ＰＥＮＧＷｅｉ（彭维），ＺＨＡＮＧＴｉｅｃｈａｎｇ（张铁昌...

Effect of dimension variation for second-harmonic generation in lithium niobate on insulator waveguide[Invited]

We study the effect of dimension variation for second-harmonic generation(SHG) in lithium niobate on insulator(LNOI)waveguides. Non-trivial SHG profiles in both type-0 and type-I quasi-phase matching are observed during the wavelength tuning of the fundamental light. Theoretical modeling shows that the SHG profile and efficiency can be greatly affected by the waveguide cross-section dimension variations, especially the thickness variations. In particular, our analysis shows that a thickness variation of tens of nanometers is in good agreement with the experimental results. Such investigations could be used to evaluate fabrication performance of LNOI-based nonlinear optical devices.

Three Dimensional Simulation of Upset Forging by Using Variational Upper Bound Method

The variation principle is discussed and Rayleigh-Ritz method is proposed for construction of veloci ty field. A kinematically admissible velocity field based on polynomials was appIied to the determina tion of forging load and deformed buIge profile during upset forging of blocks. Simulation of upsetforging of rectangular blocks under various friction condjtions was performed. Comparison of the computed results with experiments and FEM shows good agreement. It is shown that this techniquecan be used for 3D simulation of metal forming process.

Early variation of left ventricular dimension and mitral regurgitation after correction for anomalous origin of the left coronary artery from the pulmonary artery

Background Anomalous origin of the left coronary artery cardiac lesion resulting in myocardial ischemia even infarction, from the pulmonary artery is a rare congenital morphological impairment and dysfunction of left ventricle, together with mitral regurgitation. Here we will introduce our experience in the surgical repair of this kind of congenital lesion and the retrospective analysis about the improvement of left ventricular dimension and mitral regurgitation in early postoperative term. Method From May 1998 to July 2012, 38 consecutive patients with anomalous coronary artery from the pulmonary artery underwent surgical correction （33 received left coronary artery re-implantation, 4 left coronary artery ligation or primary closure, 1 Takeuchi procedure, and 10 simultaneous mitral valve plasty）. Left ventricular dimension, mitral regurgitation, and ejection fraction, were measured by color Doppler echocardiography preoperatively, and 1 month after discharge. Results Hospital survival was 94.7% （2 in-hospital deaths）. Ten paptients with more than moderate mitral regurgitation received simultaneous mitral plasty, one of whom was converted to mechanical prosthetic valve replacement. Mitral valve annuloplasty was applied in 9 cases of coronary re-implantation correction, 3 of whom also received additional mitral leaflet cleft repair. Meanwhile 8 patients underwent other different concomitant operations. Echocardiographic results for the survivals 1 month after discharge showed that left ventricular end-diastolic, endsystolic dimension decreased from 40.05 ± 5.56 mm and 28.94 ± 6.21 mm to 33.07 ± 6.82 mr, （P 〈 0.01） and 23.04 ±5.87 mm （P 〈 0.01） respectively. The average mitral regurgitation grade was also reduced from 2.36 ± 1.08 to 1.64 ± 93 （P 〈 0.05） in the group. All survival patients improved clinically and NYHA functional class decreased significantly from 2.37 ± 1.08 to 2.10 ±0.54 （P 〈 0.05）. Conclusions The surgical repair of anomalous origin of the left coronary artery from the pulmonary artery is safe and effective, and can get satisfactory dimensional and functional improvement of the left ventricle in early term. Although controversial, concomitant mitral valve plasty can be helpful for critical patients with severe mitral regurgitation.

An Improved Golden Jackal Optimization Algorithm Based on Multi-strategy Mixing for Solving Engineering Optimization Problems

Nowadays,optimization techniques are required in various engineering domains to find optimal solutions for complex problems.As a result,there is a growing tendency among scientists to enhance existing nature-inspired algorithms using various evolutionary strategies and to develop new nature-inspired optimization methods that can properly explore the feature space.The recently designed nature-inspired meta-heuristic,named the Golden Jackal Optimization(GJO),was inspired by the collaborative hunting actions of the golden jackal in nature to solve various challenging problems.However,like other approaches,the GJO has the limitations of poor exploitation ability,the ease of getting stuck in a local optimal region,and an improper balancing of exploration and exploitation.To overcome these limitations,this paper proposes an improved GJO algorithm based on multi-strategy mixing(LGJO).First,using a chaotic mapping strategy to initialize the population instead of using random parameters,this algorithm can generate initial solutions with good diversity in the search space.Second,a dynamic inertia weight based on cosine variation is proposed to make the search process more realistic and effectively balance the algorithm's global and local search capabilities.Finally,a position update strategy based on Gaussian mutation was introduced,fully utilizing the guidance role of the optimal individual to improve population diversity,effectively exploring unknown regions,and avoiding the algorithm falling into local optima.To evaluate the proposed algorithm,23 mathematical benchmark functions,CEC-2019 and CEC2021 tests are employed.The results are compared to high-quality,well-known optimization methods.The results of the proposed method are compared from different points of view,including the quality of the results,convergence behavior,and robustness.The superiority and high-quality performance of the proposed method are demonstrated by comparing the results.Furthermore,to demonstrate its applicability,it is employed to solve four constrained industrial applications.The outcomes of the experiment reveal that the proposed algorithm can solve challenging,constrained problems and is very competitive compared with other optimization algorithms.This article provides a new approach to solving real-world optimization problems.