浅谈如何深挖例题变式题型,有效提高课堂效率

课堂效率低下的问题长期困扰着类似我校生源的各校教师。经常有教师反映,同样在国重、省重的普通班一节课完成的内容,到了二、三流生源的普通学校,要想一节课完成就成了“天方夜潭”。面对这一问题,我通过教学实践和教研总结,发现了一个比较实用的解决方法。那就是深挖例题演生变式题型,有效提高学生思维层次。

Dynamic evaluation of digital and green development policies based on text mining of the PMC framework

Aiming to identify policy topics and their evolutionary logic that enhance the digital and green development(dual development)of traditional manufacturing enterprises,address weaknesses in current policies,and provide resources for refining dual development policies,a total of 15954 dual development-related policies issued by national and various departmental authorities in China from January 2000 to August 2023 were analyzed.Based on topic modeling techniques and the policy modeling consistency(PMC)framework,the evolution of policy topics was visualized,and a dynamic assessment of the policies was conducted.The results show that the digital and green development policy framework is progressively refined,and the governance philosophy shifts from a“regulatory government”paradigm to a“service-oriented government”.The support pattern evolves from“dispersed matching”to“integrated symbiosis”.However,there are still significant deficiencies in departmental cooperation,balanced measures,coordinated links,and multi-stakeholder participation.Future policy improvements should,therefore,focus on guiding multi-stakeholder participation,enhancing public demand orientation,and addressing the entire value chain.These steps aim to create an open and shared digital industry ecosystem to promote the coordinated dual development of traditional manufacturing enterprises.

聚焦教材习题,提升习题的教学功能

教材课后习题是教材的重要组成部分,笔者通过对课后习题的整理、比较和分析,阐述了教材习题的功能和价值.结合教材习题,从＂找题＂＂变题＂＂挖题＂三个角度,阐述课后习题在创设教学情境、提升学生思维广度与深度、体会数学的实验功能中的重要作用.教材课后习题除了在巩固教学,提升学生解题熟练度之外,还能参与到课堂教学中,参与到教师的备课中,参与到学生对数学的研究探索中去,充分发挥教材习题的功能!

High Slope Stability of Diversion Power System Intake of Jinchuan Hydropower Station

The excavated height of the left bank slope of the diversion power system intake in Jinchuan hydropower station is about 16o m. The stability and safety of the slope during construction and its operation/utilization become one of the most important geological engineering problems. At the same time, it is also crucial to select a safe and economic excavation gradient for the construction. We studied the problem of how to select a safe and economic slope ratio by analyzing the geological condition of the high slope, including the lithology, slope structure, structural surface and their combinations, rock weathering and unloading, hydrology, and the natural gradient. The study results showed that the use of an excavation gradient larger than the gradient observed during site investigation and the gradient recommended in standards and field practice manuals is feasible. Then, we used the finite element method and rigid limit equilibrium method to evaluate the stability of the excavation slope under natural, rainstorm and earthquake conditions. The calculated results showed that the excavated slope only has limited failure, but its stability is greatly satisfactory. The research findings can be useful in excavation and slope stabilization projects.

Calculation of foundation pit deformation caused by deep excavation considering influence of loading and unloading

A new analytical solution for ground surface settlement induced by deep excavation is proposed based on the elastic half space Melan’s solution,and the analytical model is related to the physical and mechanical properties of soil with the loading and unloading action during excavation process.The change law of earth pressure of the normal consolidation soil after the foundation pit excavation was analyzed,and elastic displacement calculation methods of analytic solution were further established given the influence of excavation and unloading.According to the change of stress state in the excavation process of foundation pit,the planar mechanical analysis model of the foundation excavation problem was established.By combining this model with the physical equations and geometric equations of plane strain problem with consideration of the loading and unloading modulus of soil,constitutive equation of the plane strain problem was also established.The loading and unloading modulus formula was obtained by using the parameter calculation method in Duncan-Chang curve model.The constitutive equation obtained from the model was used to calculate the soil stress state of each point to determine its loading and unloading modulus.Finally,the foundation pit displacement change after excavation was calculated,and thus the soil pressure distribution after retaining structure deformation.The theoretical results calculated by making corresponding programs were applied to engineering practice.By comparing the conventional calculation results with monitoring results,the practicability and feasibility of the calculation model were verified,which should provide a theoretical basis for similar projects.

Research and strategy employment information based on extension data mining

This paper uses the extension theory of knowledge, probes into the problems of students employment of College of computer science, puts forward to the solving method,specific and provides corresponding strategies. At the same time, it carries on the appraisal to provide strategy, put forward to optimal strategies; it uses of baseing on extension data mining and mining association rules of the corresponding and finding the meaning relations existing in enterprise recruitment,

The Chinese Image on Twitter： An Empirical Study Based on Text Mining

The study use crawler to get 842,917 hot tweets written in English with keyword Chinese or China. Topic modeling and sentiment analysis are used to explore the tweets. Thirty topics are extracted. Overall, 33% of the tweets relate to politics, and 20% relate to economy, 21% relate to culture, and 26% relate to society. Regarding the polarity, 55% of the tweets are positive, 31% are negative and the other 14% are neutral. There are only 25.3% of the tweets with obvious sentiment, most of them are joy.

Research on group expandable optimization decision-making model for construction programme choice

Aiming at the decision-making problem of construction programme choice,this paper advanced a new group expandable optimization decision-making model.Various factors were comprehensively considered,and the new multi-attribute evaluation index system was established.Based on the assumption that decision-makers were rational,this paper formed a group of rational preferences through extracting the personal preferences pertinently,so the decision-makers position matrix was determined.The decision-makers position matrix integrated values given by group decision-makers to construction programme comprised a matrix,of which the entropy theory for datamining was adopted in this paper to determine the attribute weights.A decision was made by using the extension decision method.Eventually,the feasibility and practicability of the model were verified by the example.