Mesoscopic analysis of the utilization of hardening model for a description of softening behavior based on disturbed state concept theory     

Jian-ye Zheng  An-li Wu 《浙江大学学报(A卷英文版)》2008,9(9):1167-1175

Mesoscopic characteristics of a clayey soil specimen subjected to macroscopic loading are examined using a medical-use computerized tomography （CT） instrument. Disturbed state concept （DSC） theory is based on the utilization of the hardening model. DSC indirectly describes material behavior by claiming that the actual response of the material is expressed in terms of the relative intact （RI） response and the fully adjusted （FA） response. The occurrence of mesoscopic structural changes of material has similarities with the occurrence of a macroscopic response of the material under loadings. In general, the relative changing value of a softening material is three to five times more than that of a hardening material. Whether special zones exist or not in a specimen cross section does not affect the following conclusion： hardening material and softening material show mechanical differences with CT statistical indices values prominently changing, and the change is related to the superposing of a disturbance factor. A new disturbance factor evolution function is proposed. Thus, mesoscopic statistical indices are introduced to describe macroscopic behavior through the new evolution function. An application of the new evolution function proves the effectiveness of the amalgamation of a macroscopic and a mesoscopic experimental phenomenon measurement methods.  相似文献   

Optimal design of pressure vessel using an improved genetic algorithm     

Peng-fei Liu  Ping Xu  Shu-xin Han  Jin-yang Zheng 《浙江大学学报(A卷英文版)》2008,9(9):1264-1269

As the idea of simulated annealing （SA） is introduced into the fitness function, an improved genetic algorithm （GA） is proposed to perform the optimal design of a pressure vessel which aims to attain the minimum weight under burst pressure constraint. The actual burst pressure is calculated using the arc-length and restart analysis in finite element analysis （FEA）. A penalty function in the fitness function is proposed to deal with the constrained problem. The effects of the population size and the number of generations in the GA on the weight and burst pressure of the vessel are explored. The optimization results using the proposed GA are also compared with those using the simple GA and the conventional Monte Carlo method.  相似文献   

A semi-custom design methodology for design performance optimization     

Dong-ming Lv  Pei-yong Zhang  Dan-dan Zheng  Xiao-lang Yan  Bo Zhang  Li Quan 《浙江大学学报(A卷英文版)》2008,9(4):510-516

We present a semi-custom design methodology based on transistor tuning to optimize the design performance Compared with other transistor tuning approaches, our tuning process takes the cross-talk effect into account and prominently reduces the complexity for circuit simulation and analysis by decomposing the circuit network utilizing graph theory. Furthermore, the incremental placement and routing for the corresponding transistor tuning in conventional approaches is not required in our methodology, which might induce timing graph variation and additional iterations for design convergence. This methodology combines the flexible automated circuit tuning and physical design tools to provide more opportunities for design optimization throughout the design cycle.  相似文献   

“培养培训一体化教师教育模式”解析——地方高师院校完善教师教育体系的探索   总被引：1，自引：0，他引：1  

刁永锋  赵正  徐东  王余勤 《大学.研究与评价》2008,(11):22-25

教师教育的培养培训一体化问题是完善教师教育体系的关键。西华师范大学将学科专业教育与教师职业教育相结合,高师的职前培养与中小学教师的职后培训相结合,构建了一种开放的培养培训一体化教师教育模式,并通过教训一体化、研训一体化、实训一体化等途径得以顺利实施。  相似文献   

职业教育中计算机网络课程的实践教学研究     

郑华  李桂红 《石家庄铁路职业技术学院学报》2008,7(3)

针对目前职业教育中面临的计算机网络课程难以开展实训的问题,探讨一种通过Boson Netsim仿真软件来进行实训的方法,通过一个具体的实例介绍了利用该软件进行网络实训的一般方法和步骤．另外,在最后还列出一系列计算机网络相关的实训项目,这些实训项目涉及计算机网络各层次的内容,对于加深学生对现代计算机网络的理解大有帮助。  相似文献   

现代学徒制下物流管理专业校企协同育人实践研究     

李政 《中国现代教育装备》2021,(1)

高职院校通过实施现代学徒制培养模式,在产教融合、校企合作,工学结合、资源共享、知行合一等方面有所突破。但校企协同育人的实践过程中也面临一些问题,制约了现代学徒制培养模式的可持续发展。广州铁路职业技术学院物流管理专业在现代学徒制校企协同育人方面开展了有效的探索,构建校企命运共同体,实现校企合作互赢。  相似文献   

恩格斯的生态文明思想及其现实意义     

郑玉美 《黄冈职业技术学院学报》2021,(2):19-22

恩格斯指出,人是自然界发展到一定历史阶段的产物,是大自然界的一部分,人类起源于大自然。解决人与自然矛盾的根本出路在于制度,在于科学技术。改革开放以来,我国以经济建设为中心,并取得了巨大的成就,成为世界经济体第二大国。但是也付出了沉重的生态代价,严重的生态问题已经影响到经济的发展,影响到人们的健康生活。恩格斯关于生态文明的思想对我国生态文明建设有着十分重要的现实意义。  相似文献   

“双一流”背景下地方高校操作系统课程教学改革研究     

李娜  李征  王鹏  达列雄  王磊 《教育技术导刊》2021,19(12):85-88

在“双一流”建设的大背景下,以提高教学质量,培养地方应用型高级专业人才为出发点,以成果或产出导向（OBE）教育理念为指导,针对计算机类专业操作系统课程进行教学改革。通过精心组织课程教学内容,采用线上线下混合教学模式,实施科学课程评价,并将课程思政教育融入专业教学全过程,以此构建地方高校操作系统一流课程。教学实践证明,学生学习效果稳步提升,教学质量进一步提高。  相似文献   

论新时代辅导员队伍建设的“时”“事”“势”     

刘征  刘伟  左殿升 《思想政治教育研究》2021,(2):154-160

十八大以来,中国特色社会主义进入新时代,培养担当民族复兴大任“时代新人”成为新时代教育的首要问题和根本任务,“新时代”和“育新人”为辅导员队伍建设设置了新情境、绘制了新蓝图、提出了新要求。新时代辅导员队伍建设要深入分析事业发展的“时”“事”“势”,以“新时代”为坐标,以“育新人”为着眼点,以立德树人为己任,以满足学生获得感为标尺,着力在讲政治、领思想、解矛盾、育新人上下功夫,不断提升队伍的理论水平、专业素养、协同意识和质量效果,努力实现辅导员队伍建设新时代创新型发展。  相似文献   

Hemin-induced increase in saponin content contributes to the alleviation of osmotic and cold stress damage to Conyza blinii in a heme oxygenase 1-dependent manner     

Zheng  Tianrun  Zhan  Junyi  Yang  Ming  Wang  Maojia  Sun  Wenjun  Shan  Zhi  Chen  Hui 《Journal of Zhejiang University. Science. B》2021,22(8):682-694

Hemin can improve the stress resistance of plants through the heme oxygenase system. Additionally, substances contained in plants, such as secondary metabolites, can improve stress resistance. However, few studies have explored the effects of hemin on secondary metabolite content. Therefore, the effects of hemin on saponin synthesis and the mechanism of plant injury relief by hemin in Conyza blinii were investigated in this study. Hemin treatment promoted plant growth and increased the antioxidant enzyme activity and saponin content of C. blinii under osmotic stress and cold stress. Further study showed that hemin could provide sufficient precursors for saponin synthesis by improving the photosynthetic capacity of C. blinii and increasing the gene expression of key enzymes in the saponin synthesis pathway, thus increasing the saponin content. Moreover, the promotion effect of hemin on saponin synthesis is dependent on heme oxygenase-1 and can be reversed by the inhibitor Zn-protoporphyrin-IX(ZnPPIX). This study revealed that hemin can increase the saponin content of C. blinii and alleviate the damage caused by abiotic stress, and it also broadened the understanding of the relationship between hemin and secondary metabolites in plant abiotic stress relief.  相似文献