Mg60Cu30Y10合金微观结构的第一性原理研究

该文利用第一性原理计算对Mg60Cu30Y10合金进行了模拟研究,分析Mg60Cu30Y10合金的几何特征：双体关联函数、三体关联函数、空间关联系数,并利用Voronoi拼砌方法对Mg60Cu30Y10合金的结构做了分析.计算发现Mg60Cu30Y10合金中Mg原子的环境与晶态Mg2Cu中的环境类似,而Cu-Y、Y-Y之间的关联对于合金的性能起着决定性的作用.     

Experimental validation of sound quality simulation and optimization of a four-cylinder diesel engine

A novel sound quality simulation approach was proposed to optimize the acoustic performance of a four-cylinder diesel engine. Finite element analysis, single-input and multiple-output technology, flexible multi-body dynamics, and boundary element codes were used to acquire the hexahedron-element model, experimental modal frequencies, vibration velocities, and structurally radiated noise of the block, respectively. The simulated modal frequencies and vibration velocities agreed well with the experimental data, which validated the finite-element block. The acoustic response showed that considerable acoustic power levels existed in 1500–1900 Hz and 2300–2800 Hz as the main frequency ranges to optimize the block acoustics. Then, the optimal block is determined in accordance with the novel approach, which reduces the overall value, high-frequency amplitudes, and peak values of acoustic power; thus, the loudness, sharpness, and roughness decline to make the sound quieter, lower-pitched, and smoother, respectively. Finally, the optimal block was cast and bench-tested. The results reveal that the sound quality of the optimal-block engine is substantially improved as numerically expected, which verifies the effectiveness of the research approach.     

Memories of a fledgling teacher: a beginning teacher's autobiography

By evoking the concept of memory pictures, the author recalls her early years as a teacher. Rather than calling herself a beginning teacher, she characterizes herself as a fledgling teacher to capture the insecurity associated with the first years of teaching. This experience is narrated through five memory pictures: (1) the new school's many rooms; (2) the staff‐room as an arena for curriculum interpretation; (3) the reading road; (4) solving mathematical problems in the classroom; and (5) the assembly hall. These five memory pictures are related to theories of learning, teacher education, visions for child‐centred education and the author's current practice as a teacher educator.     

Peer mentorship: a powerful buffer against those with legitimate right and power to bully subordinates

ABSTRACT

We used collective analytical autoethnography (CAAE) to investigate experiences of academic bullying and mobbing in our study. Specifically, four autoethnographers shared and analyzed personal experiences of being mobbed and bullied, described their perceptions of workplace bullying, its manifestations, and explored the emotional, social, psychological and career consequences associated with being bullied and mobbed at work. In addition, the autoethnographers reflected on different resources used to cope with mobbing and bullying experiences and revealed – peer mentorship and social support – as instrumental in helping them cope with both the physical and emotional distresses associated with the bullying and mobbing experiences. Implications from the findings and suggestions for future research are also presented.     

New Perspectives on the Study of Particulate Matter Deposition within Historic Interiors

ABSTRACT

This paper proposes a new way of interpreting particulate matter deposition indoors. The rate of deposition of dust in surfaces is presented as the result of the combination of two main factors: the concentration of suspended particles close to surfaces, and their capacity to deposit, expressed as the deposition velocity. We suggest that either of these two factors can be altered in order to mitigate deposition. The implications of this perspective are explored using in-situ measurements in a historic property (Apsley House, London) and a computational fluid dynamics model of aerosol deposition. The cases studied involve the effect of outdoor wind on the ingress of particles, the consequences of leaving the main door open, and the effects of the ventilation system on deposition. The results demonstrate that simulations can be used reliably to explore hypothetical scenarios or situations that would be experimentally challenging. The inputs and outputs of the computational model are discussed in view of its usability in preventive conservation.     

具有分布系数的（2＋1）维非线性薛定谔方程的精确自相似解

在已知的映射方程解的基础之上,利用自相似映射方法,通过选择合适的系统参数,给出具有分布系数的（2＋1）维非线性薛定谔系统丰富的精确自相似解,得出系统的可积约束条件,并讨论自相似解的动力学行为。     

大学排行对院校的组织决策、行为与文化的影响

大学排名不仅在学生和家长中有着巨大的影响力,而且逐渐得到了学院派的接受,成为测量和追踪大学表现和声望的有力工具。大学排名通过对利益相关者施加影响,进而影响到大学的组织行为、决策和文化。我们有必要对大学排名的诸种影响进行辨识,以更加审慎的态度使用大学排名的结果。     

Collaborative writing in engineering: Perspectives from research and implications for undergraduate education

In engineering, like in many other disciplines, collaborative writing (CW) has been identified as a central practice in both the academy and industry. A number of studies have shown that both students and professionals in this field write most discipline-specific genres collaboratively. Despite its centrality, CW in engineering is still an under-researched area with very few empirical studies on how it happens as situated practice. This article reports on a study that used a variety of data sets as its empirical base to examine CW in four schools of the faculty of engineering at a university in the UK. It also reports on the views of CW in the workplace that lecturers involved in industry hold. The article aims at contributing to the understanding of CW in engineering by identifying its role, nature and dynamics. It also examines pedagogical implications resulting from the study with a view to making a contribution to developments in writing in engineering education. The article finishes by making a number of recommendations for future research.     

Analysis and simulation of molecular dynamics of lysozyme in water cluster system

The influence of water on protein conformation was investigated by simulating the molecular dynamics of a model protein lysozyme in different water systems.The lysozyme-water system with TIP3P water model and lysozyme-water cluster system with six-ring water model were evaluated.In addition,the radial distribution function of solvent around lysozyme was calculated.It is found that the distribution of water molecules around lysozyme is similar to that of water clusters.The analyses of dihedral angles and disulfide bonds of lysozyme show that the conformation of lysozyme is severely damaged in the lysozyme-water cluster system compared with that in the lysozyme-water system.This difference can be attributed to the formation of larger number of intermolecular hydrogen bonds between lysozyme and water cluster.It is in agreement with the analysis that water clusters can change the degree of denaturation in the process of heat denaturation of lysozyme.     

组合创业影响家族企业成长的过程机制研究——基于浙江振石控股集团的案例探析

采用三角测量法,以浙江振石控股集团(全球最大玻纤制造企业)为对象,通过对访谈资料和文档资料的内容编码分析,构建了一个组合动力影响家族企业成长的PD-FBG传导模型,归纳出3类10种影响家族企业成长的组合创业传导机制。研究发现,振石控股集团的组合创业主要受企业组合动力、家族组合动力和政府组合动力的驱动,以选择型组合创业为主,适应型组合创业为辅采取创业行动,最终以企业成长为第一目标,家族成长为第二目标。振石控股集团的组合动力通过组合创业行动向家族企业成长传导,验证了"组合动力驱动组合创业,组合创业促进家族企业成长"的命题。