深度学习视域下“积件式”演示实验装置的开发和教学实践

在深度学习视域下,通过创设问题情境、提出探究主题、参与实验设计、观察实验演示、归纳实验结论和构建物理概念六大教学环节,更有利于将培养学生学科核心素养的目标贯穿于演示实验教学活动的全过程.在实践中发现,传统“单件式”演示实验装置限制了物理高效课堂的构建.立足深度学习理念,基于新课标要求,结合学情特点,对原“单件式”演示实验装置进行优化升级,开发出与深度学习视域下演示实验的教学路径相匹配的“积件式”实验装置,使演示实验教学更具深度.

“积件式”教学设计与实施

任何形式的教育均要通过课程形态(载体)表现出来。为适应"教学做一体化"课程学习模式的需要,以及将微课等信息化教学资源有效运用于课程学习之中,提出"积件式"教学设计理念,并构建课程学习"积件式"教学设计的具体框架。

Pricing American Options using the Malliavin Calculus

In this paper we elaborate a general expression of the conditional expectation related to pricing problem of the American options using the Malliavin derivative （without localization）. This work is a generalization of paper of Bally et al. （2005） [ 1 ] for the one dimensional case. Basing on the density function of the asset price, Bally and al. used the Malliavin calculus to evaluate the conditional expectation related to pricing American option problem, but in our work we use the Malliavin derivative to resolve the previous problem.

A nonlinear explicit dynamic GBT formulation for modeling impact response of thin-walled steel members

A nonlinear explicit dynamic finite element formulation based on the generalized beam theory(GBT)is proposed and developed to simulate the dynamic responses of prismatic thin-walled steel members under transverse impulsive loads.Considering the rate strengthening and thermal softening effects on member impact behavior,a modified Cowper-Symonds model for constructional steels is utilized.The element displacement field is built upon the superposition of GBT cross-section deformation modes,so arbitrary deformations such as cross-section distortions,local buckling and warping shear can all be involved by the proposed model.The amplitude function of each cross-section deformation mode is approximated by the cubic non-uniform B-spline basis functions.The Kirchhoff s thin-plate assumption is utilized in the construction of the bending related displacements.The Green-Lagrange strain tensor and the second Piola-Kirchhoff(PK2)stress tensor are employed to measure deformations and stresses at any material point,where stresses are assumed to be in plane-stress state.In order to verify the effectiveness of the proposed GBT model,three numerical cases involving impulsive loading of the thin-walled parts are given.The GBT results are compared with those of the Ls-Dyna shell finite element.It is shown that the proposed model and the shell finite element analysis has equivalent accuracy in displacement and stress.Moreover,the proposed model is much more computationally efficient and structurally clearer than the shell finite elements.

Study of the Practice Teaching Reform of Floriculture

This paper analyzes the current situation and problems of the of gardening flowers professional practice teaching, including： rigid and obsolete teaching mode, student learning enthusiasm deficiencies; practice over a single, and the lack of opportunity to practice and platform; lack of software and hardware construction, internship bases imperfect; lack of teachers＇ quality, teaching lack the times. The paper proposes a gardening the flowers professional practice teaching improvement strategies, including： innovative teaching ideas, improvement of education quality; comprehensive local conditions perfect practice, promote the construction and improvement of the practice platform; increase funding, improve the practice teachin~ base; to enhance the training and continuing education to improve practice, the overall quality of the course insla＇uctor.

Riemann-Hilbert Boundary Value Problem for the Cauchy-Riemann Equation

The Riemann-Hilbert boundary value problem for the inhomogeneous Cauchy-Riemann equation in the polydomain is considered. The sufficient and necessary solvable conditions and integral expressions of solution for the above problem are given.

Liouville theorems for an integral system with Poisson kernel on the upper half space

We investigate the Liouville theorem for an integral system with Poisson kernel on the upper half space R+n,{u（x） =2/（nωn）∫?R+n（xnf（v（y）））/（|x- y|n）dy, x ∈R+n,v（y） =2/（nωn）∫R+n（xng（u（x）））/（|x- y|n）dx, y ∈?R+n,where n 3, ωn is the volume of the unit ball in Rn. This integral system arises from the Euler-Lagrange equation corresponding to an integral inequality on the upper half space established by Hang et al.（2008）.With natural structure conditions on f and g, we classify the positive solutions of the above system based on the method of moving spheres in integral form and the inequality mentioned above.

Pulsed electrohydrodynamic printing of conductive silver patterns on demand

Pulsed electrohydrodynamic printing （EHDP） is used to fabricate conductive silver patterns with micrometer resolution. The silver ink pendant experiences swelling, pulsation, and ejection under an applied pulse voltage of 20 Hz. The droplet deposi- tion frequency is equal to the applied voltage frequency so that the EHDP can deposit silver ink on demand. A low applied voltage favors uniform and non-scattering silver patterns while a high applied voltage results in ink scattering. Discrete drop- lets with 45-55 gm in diameter and continuous tracks with 60 gm in width are generated by using a ll0-i.tm-cailber nozzle. The feature size of deposited patterns is about half of the nozzle caliber, and a finer resolution can be achieved with the intro- duction of smaller nozzle calibers. Furthermore, the appropriate curing condition is investigated for sufficient combustion of ink solvent. The minimum resistivity of 3.3 gf~ cm is demonstrated for a continuous track cured at 200~C for 10 min. Eventu- ally, several passive electrical components, such as coated resistors, interdigitated capacitors （6 pF）, and spiral inductors （0.6 gH）, are successfully fabricated.

ON THE OBSERVABILITY OF FREE BOOLEAN NETWORKS VIA THE SEMI-TENSOR PRODUCT METHOD

This paper investigates the observabihty of free Boolean networks by using the semi-tensor product method,and presents some new results.First,the concept of observability for free Boolean networks is proposed,based on which and the algebraic form of Boolean networks,a kind of observabihty matrix is constructed.Second,by the observability matrix,a new necessary and sufficient condition is given for the observability of Boolean networks.Third,the concept of observabihty index for observable Boolean networks is defined,and an algorithm is established to calculate the observability index.Finally,a practical example of D.Melanogaster segmentation polarity gene networks is studied to support our new results.The study of the illustrative example shows that the new results obtained in this paper are very effective in investigating the observability of free Boolean networks.

Positive energy theorem for(4+1)-dimensional asymptotically anti-de Sitter spacetimes

We define the total energy-momenta for(4+1)-dimensional asymptotically anti-de Sitter spacetimes,which comes from the boundary terms at infinity in the integral form of the Weitzenbck formula.Then we prove the positive energy theorem for such spacetimes,following Witten’s original argumentsfor the positive energy theorem in asymptotically flat spacetimes.