优化学程结构,促进思维培育

经过多次课程改革,小学数学学程结构已经有了良好的积淀,教师要在传承中创新,让学程的结构再优化。文章基于学程结构优化,由纵向的经验→联系→建构→应用四个递进要素,结合横向的情境→活动→回顾→评价四个平行序列,理论联系实际,呈现可操作的样例,促进学生思维结构化的培育。

学程结构设计初探

以对2009年高考大规模弃考现象的思考为研究的逻辑起点,界定学程概念并设计学程的体系结构。运用加涅的信息加工理论并结合目前流行的学习管理系统(LMS)对学程各个组成部分作有益的阐述说明,使得学程为当代教育领域中理论与技能脱节的问题提供有价值的参考。

Predictive maintenance and its applications in civil engineering structures:A review

Structural health monitoring and performance prediction are crucial for smart disaster mitigation and intelligent management of structures throughout their lifespan.Recent advancements in predictive maintenance strategies within the industrial manufacturing industry have inspired similar innovations in civil engineering,aiming to improve structural performance evaluation,damage diagnosis,and capacity prediction.This review delves into the framework of predictive maintenance and examines various existing solutions,focusing on critical areas such as data acquisition,condition monitoring,damage prognosis,and maintenance planning.Results from real-world applications of predictive maintenance in civil engineering,covering high-rise structures,deep foundation pits,and other infrastructure,are presented.The challenges of implementing predictive maintenance in civil engineering structures under current technology,such as model interpretability of data-driven methods and standards for predictive maintenance,are explored.Future research prospects within this area are also discussed.

顺自然 承四季:“四季课程”的整体构建

北京小学总结已往的课程研发经验,在整体思考本校办学理念、教学价值观、课程改革路径的基础上,推出"四季课程"。研究学校课程改革现状,构建课程开发机制;聚焦学校与学生现实需要,整体规划并系统推进"四季课程":精致规划课程安排,满足学生的个性化成长需求。

UPWIND SCHEME FOR IDEAL 2-D MHD FLOWS BASED ON UNSTRUCTURED MESH

An upwind scheme based on the unstructured mesh is developed to solve ideal 2-D magnetohydrodynamics （MHD） equations. The inviscid fluxes are approximated by using the modified advection upstream splitting method （AUSM） scheme, and a 5-stage explicit Runge-Kutta scheme is adopted in the time integration. To avoid the influence of the magnetic field divergence created during the simulation, the hyperbolic divergence cleaning method is introduced. The shock-capturing properties of the method are verified by solving the MHD shock-tube problem. Then the 2-D nozzle flow with the magnetic field is numerically simulated on the unstructured mesh. Computational results demonstrate the effects of the magnetic field and agree well with those from references.

Deterioration of concrete in railway tunnel suffering from sulfate attack

For the sake of understanding the deterioration behavior of concrete in actual railway tunnel structures subjected to aggressive sulfate medium in practice,detailed field investigations and tested analysis on sprayed concrete linings of approximately 40-year-old railway tunnels in environments containing sulfate ion were carried out,respectively.The results show that the deterioration of concretes in the investigated area is serious,which involves complicated physicochemical process between the sulfate salt and concrete.Among them,the secondary sulfateminerals such as gypsum formation under very high concentration sulfate ion condition by accumulating and evaporation process dominate,followed by the crystallization of sulfate salt and formation of thaumasite.

Influence of Nitric Acid Concentration on Characteristics of Olive Stone Based Activated Carbon

In this work we investigated the effect of nitric acid concentration on the pore structure,surface chemistry and liquid phase adsorption of olive stone based activated carbon prepared by mixing process using phosphoric acid and steam as activating agents.Chemicals and textural characterization show that the increase of HNO3concentration increases considerably the total acidic groups but decreases specific surface area and pore volume.The study of adsorption in aqueous solutions of two organics,phenol and methylene blue,on raw and oxidized activated carbon indicates that the treatment of mixed activated carbon with different concentrations of nitric acid improves the adsorbent capacity for methylene blue at HNO3concentrations less or equal to 2 mol·L 1,while it has a negative effect on phenol adsorption.

Market based framework for multiple AUVs cooperation

A“Market” based framework for multiple AUVs team is introduced in this paper.It is a distributed meta-level task allocation framwork. The formulation and the basic concepts of the “Market” such as “goods” and “price” are discussed first, then the basic algorithm of the “auction”. The loosely coupled v-MDTSP tasks are considered as an example of the task allocation mission. A multiple AUV team controller and a detailed algorithm are developed for such applications. The simulation results show that the controller has the advantages such as robustness and low complexity and it can achieve better optimization results than the classical central controller (such as GA) in some tasks. And the comparison of two different local solvers also implies that we should get the reasonable task allocation even not using the high quality algorithm, which can considerably decrease the cooperation computation.

Phylogeny of forkhead genes in three spiralians and their expression in Pacific oyster Crassostrea gigas

The Fox genes encode a group of transcription factors that contain a forkhead domain, which forms a structure known as a winged helix. These transcription factors play a crucial role in several key biological processes, including development. High-degree identity in the canonical forkhead domain has been used to divide Fox proteins into 23 families （FoxA to FoxS）. We surveyed the genome of three spiralians, the oyster Crassostrea gigas, the limpet Lottia gigantea, and the annelid Capitella teleta. We identified 25 C. gigas fox genes, 21 L. gigantea fox genes, and 25 C. teleta fox genes. The C. gigas fox and L. giganteafox genes represented 19 of the 23 families, whereas FoxI, QI, R, and S were missing. The majority of the Fox families were observed within the C. teletafox genes, with the exception of FoxR and S. In addition, thefoxAB-like gene,foxY-like gene, andfoxH gene were also present in the three genomes. The conserved FoxC-FoxL 1 cluster, observed in mammals, was also found in C. gigas. The diversity of temporal expression patterns observed across the developmental process implies the C. gigasfox genes exert a wide range of functions. Further functional studies are required to gain insight into the evolution of Fox genes in bilaterians.

Structural safety monitoring for Nanjing Yangtze River Bridge

In order to evaluate objectively and accurately the integrity, safety and operating conditions in real time for the Nanjing Yangtze River Bridge, a large structural safety monitoring system was described. The monitoring system is composed of three parts: sensor system, signal sampling and processing system, and safety monitoring and assessment system. Combining theoretical analysis with measured data analysis, main monitoring contents and layout of measuring points were determined. The vibration response monitoring was significantly investigated. The main contents of safety monitoring on vibration response monitoring are vibration of the main body of the Nanjing Yangtze river bridge, collision avoidance of the bridge piers, vibration of girders on high piers for the bridge approach and earthquake. As a field laboratory, the safety monitorying system also provides information to investigate the unknown and indeterminate problems on bridge structures and specific environment around bridges.

The Design of Water-reusing Network with a Hybrid Structure Through Mathematical Programming

A new design method for a water-reusing network, with a hybrid structure, to reduce the complexity of the network and to minimize freshwater consumption, is proposed. The unique feature of the methodology proposed .in this article is to control the complexity of the water network by regulation of the control number in a water-reusing system. It combines the advantages of a conventional water-reusing network and a water-reusing net work with internal water mains. To illustrate the proposed method, a single contaminant system and a multiple contaminant system serve as examples of the problems.

Motivating Teachers

Teachers can motivate their pupils by fostering autonomous learning or---especially if they feel under pressure themselves--teachers can hamper the motivation of their students by being controlling. The purpose of this study with 488 secondary school teachers from Austria was to examine the satisfaction of teachers＇ needs for autonomy, competence and relatedness and meaningful relations to perceived job-related pressure and self-efficacy, to gain an increased insight in autonomy supportive contexts. The results point out that there are various sources for pressure in the teaching profession and structural equation modeling revealing a reciprocal relation between the satisfaction of the need for autonomy and pressure in teaching, as well as between the satisfaction of the need for competence and self-efficacy. In addition perceived pressure had a negative impact on teachers＇ self-efficacy and self-efficacy in turn influenced the satisfaction of the need for autonomy. In summary, considering basic psychological needs satisfaction of teachers seems relevant to create autonomy supportive environments for pupils and teachers in schools.

Covariant Prolongation Structure of Konno-Asai-Kakuhata Equation

Based upon the covariant prolongation structures theory, we construct the sl（2, R）×R（p） prolongation structure for Konno-Asai-Kakuhata equation. By taking two and one-dimensional prolongation spaces, we obtain the inverse scattering equations given by Konno et al. and the corresponding Riccati equation. The Baecklund transformations are also presented.

Prolongation Structure of Semi-discrete Nonlinear Evolution Equations

Based on noncommutative differential calculus, we present a theory of prolongation structure for semidiscrete non/inear evolution equations. As an illustrative example, a semi-discrete model of the non/inear SchrSdinger equation is discussed in terms of this theory and the corresponding Lax pairs are also given.

A new method determining safe thickness of karst cave roof under pile tip

Cave roofs are used to support pile foundation in many engineering projects. Accurate stability analysis method of cave roof under pile tip is important in order to ensure the safety of the pile foundation structure. Firstly the mechanical model to analysis the stability of cave roof under pile tip is founded aiming to solve the problems that the simplified mechanical model has. Secondly, the boundary of cave roof is simply supposed to be supported according to the integrity of the rock mass in the boundary of cave roof. Thirdly, based on the theory of plates and shells, the simplified model is calculated and the theoretical calculation formula to determine the safe thickness of cave roof under pile tip can be obtained when the edges of the cave roof are simply supported. In the end, the analysis of the practical engineering project proves the feasibility and the rationality of the method which can be a new method to calculate the safe thickness of cave roof under pile tip.

The Feasibility of Flipped Classroom Teaching Model in the Writing Course via ICLASS for Non-English Major Students

The present paper probes into the feasibility of flipped classroom teaching model in writing for non-English majors The flipped classroom teaching model changes the teaching structure in the traditional classrooms. It puts students at the center of study in the whole study process, gives more autonomy to students both in class and outside of class, and involves students in the cooperation and interaction with their peers or the teacher. The process of writing teaching in the flipped classrooms via ICLASS is designed in the present paper and hopefully it will help non-English major students to improve their overall proficiency in writing.

Efficient generation of Bell-cat states in remote cavities

In the context of cavity quantum electrodynamics (QED),a potential scheme is proposed to generate entangled coherent states. The scheme includes twice interactions of two-level atoms with cavities. In the first interaction,two atoms are sent into a microwave cavity with the large detuning respectively. And then the second interaction is that the two atoms enter another microwave cavity and are driven by a resonant classical field meantime. When we choose the proper interaction time and make measurement on the two atoms,the two microwave cavity mode fields are determinatively entangled. In addition,it is easy to generalize the scheme to multi-cavity and multi-atom.

Marine Structures: Future Trends and the Role of Universities

This paper emphasizes some of the challenges and trends associated with the future development of marine structures. Its main focus is on ways to improve the efficiency of energy-consuming ships, and on design challenges related to energy-producing offshore structures. This paper also discusses the analysis tools that are most needed to enable sustainable designs for future ships and offshore structures. The last section of the paper contains thoughts on the role of universities in education, research, and innovation regarding marine structures. It discusses curriculum requirements for maritime-technology education, basic research activities, and international cooperation.

Unification of Gravity and Electromagnetism

Gravity and electromagnetism are two sides of the same coin, which is the clue of this unification. Gravity and electromagnetism are represented by two mathematical structures, symmetric and antisymmetric respectively. Einstein gravitational field equation is the symmetric mathematical structure. Electrodynamics Lagrangian is three parts, for electromagnetic field, Dirac field and interaction term. The definition of canonical energy momentum tensor was used for each term in Electrodynamics Lagrangian to construct the antisymmetric mathematical structure; symmetric and antisymmetric gravitational field equations are two sides of the same Lagrangian.

Structured Graduate Programs Design Proposal for UNEXPO Institutions System

The UNEXPO （National Experimental Polytechnic University） system is a public institution dedicated to teaching and researching in engineering area. It was formed to bring together three main institutes located in Venezuelan cities and three more institutes located in rural areas, so that to collectively and collaboratively serve the regions in optimal ways. The academic activity started in 1982 graduating engineers and technicians, although less effort has shown by authorities to develop programs in graduate engineering areas. A proposal for designing a structured graduate program is presented. The structured program presented, will hopefully set the basis to develop graduate and doctoral studies in engineering and related areas to the whole university system, and to achieve academic and social development to the country.