Regulating surface wrinkles using light

Regulating existing micro and nano wrinkle structures into desired configurations is urgently necessary yet remains challenging, especially modulating wrinkle direction and location on demand. In this work, we propose a novel light-controlled strategy for surface wrinkles, which can dynamically and precisely regulate all basic characteristics of wrinkles, including wavelength, amplitude, direction and location (λ, A, θ and L_c), and arbitrarily tune wrinkle topographies in two dimensions (2D). By considering the bidirectional Poisson''s effect and soft boundary conditions, a modified theoretical model depicting the relation between stress distributions and the basic characteristics was developed to reveal the mechanical mechanism of the regulation strategy. Furthermore, the resulting 2D ordered wrinkles can be used as a dynamic optical grating and a smart template to reversibly regulate the morphology of various functional materials. This study will pave the way for wrinkle regulation and guide fabrication technology for functional wrinkled surfaces.     

On theory and methods for advanced detonation-driven hypervelocity shock tunnels

This study describes theory and methods for developing detonation-driven shock tunnels in hypervelocity test facilities. The primary concept and equations for high-enthalpy shock tunnels are presented first to demonstrate the unique advantage of shock tubes for aerodynamic ground-based testing. Then, the difficulties in simulating flight conditions in hypervelocity shock tunnels are identified, and discussed in detail to address critical issues underlying these difficulties. Theory and methods for developing detonation drivers are proposed, and relevant progress that has advanced the state of the art in large-scale hypersonic test facilities is presented with experimental verifications. Finally, tailored conditions for detonation-driven shock tunnels are described, laying a solid foundation to achieve long test duration. This interface-matching key issue encountered in developing shock tunnels has been investigated for decades, but not solved for detonation drivers in engineering applications.     

浅谈物理实验教学的原则

物理是一门以实验为基础的学科.按照配备标准Ⅰ类实验室学生实验是25组,Ⅱ类实验室学生实验是13组,按照标准班容量50人/班,Ⅱ类就只能4人一组,而我市初级中学基本上是Ⅱ类实验室.因此,在实验课上能动手做实验的学生很少.这样,真正由学生自己探索问题、解决问题、总结实验观点、实验结论的相对来说就少了.又走上了一个传统的教师理论讲授,学生进行练习的模式,不利于学生观察、分析问题的能力提高,自主学习和研究性的学习方法也难以形成.     

一个制取液态二氧化硫的实验

1原理 SO2是一种易液化的气体（常压下沸点是-10℃）,也容易被活性炭吸附。若把吸附有SO2的活性炭封在玻璃管里,可以利用它的热离解平衡实现SO2的解吸和吸附。     

中国科协服务科技经济融合发展的模式机制研究

在国际竞争愈发激烈和国内疫情防控常态化的新形势下,中国科协作为组织科技创新各方力量的重要平台,担当着服务科技经济融合发展的时代使命和重要责任.尽管科协服务科技经济融合发展已经取得一些成效,但是仍然存在数字化平台功能单一、激励机制欠缺、供需对接不够精准、可持续发展机制欠缺等问题.立足科协服务科技经济融合发展的实践及发展趋...     

图书馆在本科教学评估中的地位及对评估指标的理解

文章根据10年来的教学评估情况,阐明了本科教学评估的内涵、特征和意义,分析了图书馆在本科教学评估中的地位及图书馆评估指标的内涵,进一步探讨了评估工作对图书馆产生的影响.参考文献7.     

Mineralogy of the deep lower mantle in the presence of H2O

Understanding the mineralogy of the Earth''s interior is a prerequisite for unravelling the evolution and dynamics of our planet. Here, we conducted high pressure-temperature experiments mimicking the conditions of the deep lower mantle (DLM, 1800–2890 km in depth) and observed surprising mineralogical transformations in the presence of water. Ferropericlase, (Mg, Fe)O, which is the most abundant oxide mineral in Earth, reacts with H₂O to form a previously unknown (Mg, Fe)O₂H_x (x ≤ 1) phase. The (Mg, Fe)O₂H_x has a pyrite structure and it coexists with the dominant silicate phases, bridgmanite and post-perovskite. Depending on Mg content and geotherm temperatures, the transformation may occur at 1800 km for (Mg_0.6Fe_0.4)O or beyond 2300 km for (Mg_0.7Fe_0.3)O. The (Mg, Fe)O₂H_x is an oxygen excess phase that stores an excessive amount of oxygen beyond the charge balance of maximum cation valences (Mg²⁺, Fe³⁺ and H⁺). This important phase has a number of far-reaching implications including extreme redox inhomogeneity, deep-oxygen reservoirs in the DLM and an internal source for modulating oxygen in the atmosphere.     

顾客价值的目标化管理

本文在目前已经进行的顾客价值理论研究的基础上,力图引入经典管理思想之一的目标管理对市场营销活动的关键内容之一,即顾客价值创造活动进行有效管理,从而使顾客价值理论具有更强的可操作性,成为企业可持续竞争力的来源之一。     

不一样的美国学校生活

2008年,我作为衢州市的交流教师,在美国明尼苏达州雷德温市的公立学校任教三个多月,亲历了学校生活的方方面面,感受了不一样的美国学校生活。     

和谐社会视野中的社会保障

公平正义是社会主义和谐社会的重要特征,也是社会保障制度的核心价值。社会保障同和谐社会的内在联系,决定了加强社会保障可以保障人权、体现社会公平,促进个体和谐、阶层和谐以及党群和谐,实现社会和谐。