Search

Existing optimization research on the crankshaft heat treatment process is mostly based on one-sided considerations, and less consideration is given to the matching of multiple process parameters, leading to irrational designs of heat treatment. To address this problem, this work investigates the influence mechanisms of cooling speed, tempering temperature, and holding time on the performance evaluation indexes of the straightness, residual stress, and martensite content of a crankshaft based on the response surface method. The results showed that the order of influence of these three different process parameters on the performance evaluation index was cooling speed > holding time > tempering temperature, and the order of influence on the performance evaluation indexes under multifactorial process parameters was cooling speed–holding time > cooling speed–tempering temperature > holding time–tempering temperature. The optimal process parameters were a cooling speed of 1.4 times the cooling oil, a tempering temperature of 555 °C, and a holding time of 6 h, with the straightness of the crankshaft reduced by 9.9%, the surface stress increased by 6.7%, and the martensitic content increased by 7.2% after the process optimization. This work can provide new clues for optimizing the heat treatment process parameters of crankshafts. [ABSTRACT FROM AUTHOR]

Recently, the studies of topological corner states (TCSs) have been extended from crystals to quasicrystals, which are referred to as higher‐order topological quasicrystalline insulators (HOTQIs). However, the TCSs of complete quasi‐periodic structure in photonic systems have yet to be demonstrated. Moreover, there is only one TCS in each corner region in higher‐order topological insulators (HOTIs). Increasing the number of TCS is expected to increase the application potential of TCSs. In this work, HOTQIs in photonic systems are experimentally observed. It is found that HOTQIs possess TCS arrays, and each TCS array contains several TCSs. Furthermore, the universal theoretical framework of the multimer analysis method is improved, and the difference in the average charge density is proposed as a real‐space topological index. These results will open up new ideas for investigating highly integrated, multi‐region localized TCSs and are expected to provide new ways to explore topological phenomena and the applications of photonic quasicrystals. [ABSTRACT FROM AUTHOR]

This paper focuses on the study of the induction heating process of a camshaft in a marine diesel engine. A three-dimensional finite element model for dynamic induction heating is established using the finite element method of multi-physical field coupling, aiming to investigate the temperature uniformity of the cam during this process. Three elements are analyzed in this study: the moving speed, the gap between the induction coil and the workpiece, and the width of the induction coil. These factors allow for an analysis of the temperature distribution in the thickness direction and contour line direction of the cam under various conditions. On this basis, an equivalent parameter about the temperature uniformity in the thickness direction of the cam is proposed to guide the selection of the camshaft induction heating process parameters. [ABSTRACT FROM AUTHOR]

Colorectal anastomosis remains a key aspect in mid- and lower-rectal surgery, particularly in patients who are male, obese, status post neoadjuvant chemoradiation, or possess narrow pelvic anatomy. Transanal total mesorectal excision (taTME) and transabdominal total mesorectal excision (TME) both primarily allow position of the tumor to dictate whether circular stapling or hand-sewing is utilized to achieve anastomosis. Given that taTME only requires a single circular stapler to achieve anastomosis, it consequently decreases the risk of jeopardizing blood supply to the anastomotic site. Should transanal hand-sewing be pursued, numerous points in performing the purse-string suture warrant particular attention: (1) Before suturing, separate the distal rectum to be anastomosed from the surrounding tissues, and ensure the full-layer suture of the distal purse-stitched suture. (2) It is recommended that beginners complete the suturing process under direct visualization without removing the transanal platform. (3) Commonly used anastomosis designs include end-to-end, side-to-end, J-pouch, or coloplasty, depending on patient characteristics and surgeon preferences. Our single-institution clinical experience suggests that taTME patients who underwent neoadjuvant chemoradiation or transanal hand-sewn anastomosis should still have a temporary colostomy created. To date, literature has yet to demonstrate the superiority of taTME anastomosis outcomes. This publication aims to point out anastomosis techniques and safety pointers, as well as clinical experiences.