On design of continuous Lyapunov's feedback control

A common approach to Lyapunov's stability control is to design a controller such that a Lyapunov function can be derived for the control system to ensure stability. This procedure often leads to a discontinuous controller. When the controller is implemented, the discontinuous terms are replaced with continuous functions to avoid chattering of the control signal. Two associated problems have been overlooked during this procedure. One is that discontinuous control systems are non-smooth, which violates the fundamental assumptions of solution theories and the applicability of Lyapunov's stability theory is questionable. Another problem is that the replacement of discontinuous terms may weaken stability, which can be critical. In this paper, we discuss proper stability analysis of discontinuous control systems using the extended Lyapunov's second method based on Filippov's solution concept for non-smooth systems. We further propose to utilize the concept of Lyapunov exponents to quantitatively analyze the stability of continuous control systems obtained by replacing the discontinuous terms in the discontinuous controllers. An example involving the stabilization of a two-link non-fixed-base robotic manipulator is presented for demonstration. This research fills the gap in designing continuous Lyapunov's stability controllers regarding limited available Lyapunov functions.     

Fingerprinting the mind

Until recently the identification of the authorship of written works has—like that of paintings—been largely subjective, but the application of the computer to analysis of literary structure has opened up important new possibilities. It has shown that simple frequency patterns are of much less diagnostic value than groupings of words and their position in sentences. Stylometry, as this new investigative method is called, has the merit of knowing no language barriers—it is equally applicable, for example, to classical Greek, English, and Swedish.     

五次对称准周期晶格的电子状态结构研究

文中对计算电子结构的集团Ｂｅｔｈｅ晶格方法进行了改进。简化了原子集团的选取方式，提出了求解复数Ｄｙｓｏｎ方程组的矩阵解方法和平均集团Ｂｅｔｈｅ晶格方法。研究了Ｐｅｎｒｏｓｅ　ｔｉｌｉｎｇ的局部、整体和平均电子状态密度。发现了Ｐｅｎｒｏｓｅ　ｔｉｌｉｎｇ的局部电子状态密度对准周期点阵的长程有序性特别敏感的性质。提出了计算Ｐｅｎｒｏｓｅ　ｔｉｌｉｎｇ局部及整体电子状态密度应遵循的原则．得出了某些合金的准晶相可能是电子化合物的结论。     

Construction of hollow mesoporous silica nanoreactors for enhanced photo-oxidations over Au-Pt catalysts

It is highly desirable to design hollow structures with multi-scale functions by mimicking cells for the construction of micro/nanoreactors. Herein, we report the construction of hollow-structured submicrometer-photoreactors with bimetallic catalysts loaded within mesoporous silicas. The synthesis parameters are optimized to study the evolution of hollow structure through hydrothermal treatment and an ‘adhesive-contraction’ formation mechanism is proposed. AuPt@HMZS catalysts exhibited a broader absorbance region under visible light and the adsorption edge displayed a red-shift, indicating the strong metal–metal interactions at the alloy interface. The reaction performance of the coupled Au-Pt catalysts can be tuned to achieve excellent catalytic activity in cinnamyl alcohol oxidation to cinnamic acid for 3.1 mmol g⁻¹ with 99% selectivity. The proposed strategy to build hollow structures as multifunctional micro/nanoreactors is promising for the design of high-performance and sustainable catalysts for chemical synthesis.     

Write this way: examining teachers’ supportive strategies to facilitate children’s early writing in preschool

Reading and Writing - Writing is essential for communication in literate societies, and its successful acquisition and development is central to academic achievement. Beginning in early childhood,...     

Curriculum spaces for connecting to children’s multiple mathematical knowledge bases

Elementary mathematics curriculum materials can serve as a lever for instructional change. In this paper, we promote a particular kind of instructional change: supporting teachers in learning to integrate children’s multiple mathematical knowledge bases (MMKB), including children’s mathematical thinking and children’s home and community-based mathematical funds of knowledge, in instruction. A powerful means of supporting pre-service teachers in integrating children’s MMKB in instruction may be to scaffold teachers’ noticing of potential spaces in elementary mathematics curriculum materials for connecting to children’s MMKB and then developing practices for leveraging these spaces during instruction. We focus on existing and potential spaces in written curriculum materials, or curriculum spaces, so as to better support teachers in enacting curriculum that opens spaces for connecting to children’s MMKB.     

由非线性粒子运动方程导出薛定锷方程

本文将由非线性量子动力学方程同时导出薛定锷方程和牛顿方程．这样就不仅证明了经典力学与量子力学已被统一了起来，且证明了薛定锷场(波函数)不是非物质性的几率波．而是刻出物质性背景空间性质的物质性场．     

Research Active Programme: A pilot inclusive research curriculum in higher education

Participation of people with disabilities in producing and using research is critical for monitoring the implementation of the United Nations Convention on the Rights of Persons with Disabilities (CRPD). The Research Active Programme (RAP) is a module designed to build research capacity of students with intellectual disabilities. RAP was implemented over 11 weeks in 2 Irish universities. The mixed methods programme evaluation was completed from the students' perspectives, attending to curriculum content, pedagogical approach, the research knowledge and skills acquired by students. Twenty-five students completed interviews before and after engaging in RAP. Focus groups and quizzes were held after sessions to assess learning outcomes. Content analysis was used to interpret student perspectives. RAP was an effective approach for supporting students with intellectual disabilities to develop introductory research knowledge and skills; however, across the cohort, there were differences in demonstrated learning. Student expectations with respect to overall curriculum design, learning outcomes and delivery were reviewed. Specifically, learning outcomes, module delivery and assessment strategies were critiqued. Overall, the RAP curriculum supported research skill development in students. This module prepared people with intellectual disabilities to engage more fully as research partners in monitoring the implementation of the CRPD.