Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects,so even large-scale commercial finite element software cannot finish the complicated analysis.A ...Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects,so even large-scale commercial finite element software cannot finish the complicated analysis.A finite element method of 3D transient coupled thermo-elastic-plastic contact sealing analysis for reactor pressure vessels is presented,in which the surface nonlinearity,material nonlinearity,transient heat transfer nonlinearity and multiple coupled effect are taken into account and the sealing equation is coupling solved in iterative procedure.At the same time,a computational analysis program is developed,which is applied in the sealing analysis of experimental reactor pressure vessel,and the numerical results are in good coincidence with the experimental resuits.This program is also successful in analyzing the practical problem in engineering.展开更多
After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare thei...After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare their difference concerning properties and microstructure. Experiment results indicate that tooth surface of the coated-TiN gears does not suffer surface abnormalities in meshed zone. Instead, the gears with nitrided case exhibit an abrasion mark on the meshed zone of tooth surface, which results in more weight loss of nitrided gears. The morphology of the surface suggests TiN film with more than 2 000 HV is so dense and smooth that coated-TiN gears have higher wear resistance compared with the uncoated gears. The microstructure of coated-TiN gears is finer, hardness is higher and its distribution of coated-TiN gears is more reliable than uncoated ones, which makes nitride layer combined with TiN film tightly. Consequently, the wear-resistance of gears has been dramatically promoted.展开更多
在肿瘤的发生发展过程中通常伴随肿瘤细胞代谢的重编程,以满足其对肿瘤微环境的适应及能量的获取。脂质代谢异常目前已成为肿瘤细胞代谢重编程的主要标志之一,而甲羟戊酸途径(mevalonate pathway,MVA)作为脂质代谢中重要的胆固醇生物合...在肿瘤的发生发展过程中通常伴随肿瘤细胞代谢的重编程,以满足其对肿瘤微环境的适应及能量的获取。脂质代谢异常目前已成为肿瘤细胞代谢重编程的主要标志之一,而甲羟戊酸途径(mevalonate pathway,MVA)作为脂质代谢中重要的胆固醇生物合成途径,在肿瘤细胞中呈异常活跃状态。肿瘤细胞中突变型p53(mutant p53,mutp53)的代谢重组功能与MVA途径的活跃状态有密不可分的关系,mutp53可通过固醇类转录因子SREBP2(sterol response element binding protein 2)激活MVA途径,并进一步稳定自身表达,两者之间的相互作用促进了肿瘤细胞的异常增殖。该文通过对肿瘤细胞中mutp53与MVA途径之间相互调控机制的最新研究进展进行综述,为探寻靶向mutp53和MVA途径的新的肿瘤治疗方案提供思路。展开更多
Incorporated with constitutive relationship established by artificial need networks (ANN), a coupled thermoviscoplastic finite element procedure is developed for predicting the microstructure evolution in the hot forg...Incorporated with constitutive relationship established by artificial need networks (ANN), a coupled thermoviscoplastic finite element procedure is developed for predicting the microstructure evolution in the hot forging process, considering the factors such as dynamic recrystallization, static recrystallization and grain growth etc. This software system is applied to predict the distributions of the grain size over the crosssection of stigmata, which is found to be in good agreement with the experimental results. The software can provide a fundament for optimizing technological parameters.展开更多
A mixed finite element solution of contact stresses in meshing gears is investigated with the consideration of coupled thermo-elastic deformation and impact behavior. A simulation procedure of finite element solution ...A mixed finite element solution of contact stresses in meshing gears is investigated with the consideration of coupled thermo-elastic deformation and impact behavior. A simulation procedure of finite element solution of meshing gears is developed. The versatility of the procedure for both numerical accuracy and computational efficiency is verified by numerical analysis of meshing gear teeth.展开更多
A very useful new method of tooth contact finite element analysis(TCFEA) for spiralbevel and hypoid gears is presented, combines 3-d finite element contact stress analysis withLTCA (Loaded Tooth Contact Analysis). The...A very useful new method of tooth contact finite element analysis(TCFEA) for spiralbevel and hypoid gears is presented, combines 3-d finite element contact stress analysis withLTCA (Loaded Tooth Contact Analysis). The TCFEA uses mixed finite element method to ana-lyze the 3-d contact stress. The related formulas are derived and an efficient analyzing method asseveral pairs of teeth in contact occurs is presented, which greatly reduce the computationalamount. It is of great significance that the tooth stress. geometry. contact condition and load areall considered in the same model. Finally the related experimental results are used to verify thesolution of TCFEA .展开更多
文摘Sealing analysis of sealing system in reactor pressure vessels is relevant with multiple nonlinear coupled-field effects,so even large-scale commercial finite element software cannot finish the complicated analysis.A finite element method of 3D transient coupled thermo-elastic-plastic contact sealing analysis for reactor pressure vessels is presented,in which the surface nonlinearity,material nonlinearity,transient heat transfer nonlinearity and multiple coupled effect are taken into account and the sealing equation is coupling solved in iterative procedure.At the same time,a computational analysis program is developed,which is applied in the sealing analysis of experimental reactor pressure vessel,and the numerical results are in good coincidence with the experimental resuits.This program is also successful in analyzing the practical problem in engineering.
基金This project is supported by National Natural Science Foundation of China(No.50375164)Visitor Scholar Project of State Key Laboratory of Mechanical Transmission in Chongqing University,China.
文摘After 32CrMoV is selected to manufacture nitrided gears coated with TiN by multi-arc ion plating, all of these uncoated gears and coated gears run in the gearbox under the same initial conditions so as to compare their difference concerning properties and microstructure. Experiment results indicate that tooth surface of the coated-TiN gears does not suffer surface abnormalities in meshed zone. Instead, the gears with nitrided case exhibit an abrasion mark on the meshed zone of tooth surface, which results in more weight loss of nitrided gears. The morphology of the surface suggests TiN film with more than 2 000 HV is so dense and smooth that coated-TiN gears have higher wear resistance compared with the uncoated gears. The microstructure of coated-TiN gears is finer, hardness is higher and its distribution of coated-TiN gears is more reliable than uncoated ones, which makes nitride layer combined with TiN film tightly. Consequently, the wear-resistance of gears has been dramatically promoted.
文摘在肿瘤的发生发展过程中通常伴随肿瘤细胞代谢的重编程,以满足其对肿瘤微环境的适应及能量的获取。脂质代谢异常目前已成为肿瘤细胞代谢重编程的主要标志之一,而甲羟戊酸途径(mevalonate pathway,MVA)作为脂质代谢中重要的胆固醇生物合成途径,在肿瘤细胞中呈异常活跃状态。肿瘤细胞中突变型p53(mutant p53,mutp53)的代谢重组功能与MVA途径的活跃状态有密不可分的关系,mutp53可通过固醇类转录因子SREBP2(sterol response element binding protein 2)激活MVA途径,并进一步稳定自身表达,两者之间的相互作用促进了肿瘤细胞的异常增殖。该文通过对肿瘤细胞中mutp53与MVA途径之间相互调控机制的最新研究进展进行综述,为探寻靶向mutp53和MVA途径的新的肿瘤治疗方案提供思路。
文摘Incorporated with constitutive relationship established by artificial need networks (ANN), a coupled thermoviscoplastic finite element procedure is developed for predicting the microstructure evolution in the hot forging process, considering the factors such as dynamic recrystallization, static recrystallization and grain growth etc. This software system is applied to predict the distributions of the grain size over the crosssection of stigmata, which is found to be in good agreement with the experimental results. The software can provide a fundament for optimizing technological parameters.
文摘A mixed finite element solution of contact stresses in meshing gears is investigated with the consideration of coupled thermo-elastic deformation and impact behavior. A simulation procedure of finite element solution of meshing gears is developed. The versatility of the procedure for both numerical accuracy and computational efficiency is verified by numerical analysis of meshing gear teeth.
文摘A very useful new method of tooth contact finite element analysis(TCFEA) for spiralbevel and hypoid gears is presented, combines 3-d finite element contact stress analysis withLTCA (Loaded Tooth Contact Analysis). The TCFEA uses mixed finite element method to ana-lyze the 3-d contact stress. The related formulas are derived and an efficient analyzing method asseveral pairs of teeth in contact occurs is presented, which greatly reduce the computationalamount. It is of great significance that the tooth stress. geometry. contact condition and load areall considered in the same model. Finally the related experimental results are used to verify thesolution of TCFEA .
