基于“显性”方法 培养学生科学本质观

培养学生的科学本质观是科学教育的重要目标之一,本文通过改变科学史的教学方式、创新多种科学探究方式和优化社会性科学议题的教学方式,探索发展学生科学本质观的有效路径。

江浙小调的“显性”风格制造——兼论江浙小调对中国民歌的贡献

在浩如烟海的中国民歌系中,江浙小调以其特有的音乐品质、深厚的人文底蕴而广播四方。它在历史进程中兼收并蓄其他地区的民族音乐,厚积薄发,以千年沉淀之芬芳辐射四围,为中国民族民歌提供了丰富的养料,作出了高质量的贡献。江浙小调这种"显性"风格的形成离不开中国大文化环境的滋补、熏陶,又与自我特殊的地理文化特质紧密相关,从而形成具有鲜明地域特色的音乐品牌。

浅谈江浙小调的“显性”风格制造——兼论江浙小调对中国民歌的贡献

众所周知,我国的民歌文化极为深厚广博。其中,江浙小调凭借独特的音乐特性和丰富的文化内涵在我国地方民歌中独树一帜,并对我国民歌的发展作出了巨大的贡献。因此,本文基于江浙小调的"显性"风格,重点探究了"显性"风格的形成特点和江浙小调对中国民歌的贡献,以期为相关研究人员提供参考和借鉴。

巧抓“隐性”表达 精彩“显性”表达

语文是最重要的交际工具，语文课程是一门学习语言文字运用的综合性、实践性课程。也许就是我们在训练表达的过程中只重视了“显性”的表达，却忽视了“隐性”的表达。在语文教学中，还存在着一种“隐性”的表达，它是通过阅读文本进行理解与感受——是一种把作者的表达“内化”为自己的表达的过程。这种“隐性”表达是“显性”表达的生成，渗透着表达中的人文熏陶，

论小学语文课堂中传统文化内容教学的“显性”与“隐性”

我国教育学者一直对传统文化有所研究,但是语文教材中的传统文化渗透并不多,缺少对部编版小学语文教材中传统文化运用研究。同时中华传统文化作为我国发展精神根基,语文教材作为传承优秀传统文化的主要载体,在教学中融合中国传统文化,已经是时代与学生发展的必然需求。基于此,本文从教材中“隐性”与“显性”传统文化教学内容入手,阐述教学过程,旨在通过此为教师教学带来启发。

浅析英语口语隐性课程的“显性控制”

隐性课程是显性课程的拓展和延伸,是学校教育不可或缺的部分。英语口语隐性课程的"显性控制",对学生英语口语水平的提高至关重要,对课程组织者提出了更高的要求。本文介绍了英语口语隐性课程的研究背景、涵义和特点,阐述了对其研究的重要性,着重强调如何在教学过程中对英语口语隐性因素加以"显性"控制,为学生创造一个良好的英语口语学习环境,以提高学生的学习兴趣,达到教学目的。

司法对“台独”行为的认定与制裁

以司法形式解决政治争端问题是现代法治文明的标志,对“台独”行为采取司法审判是依法解决台湾问题过程中必不可少的一环。经过多年建设,我国基本形成了反分裂法律体系,为司法制裁“台独”提供了法律依据。在司法审判的机构设置上,可以考虑采取专门机构的常态化审判和特殊法庭的非常态化审判两种机制。在对“台独”行为的司法认定与制裁上,辨别隐性“台独”行为的分裂性质并证成国家统一之法理是关键难题。中国是主权国家与祖国的统一体。“台独”行为侵犯的国家统一之法益,既包含主权统一,也包含祖国统一。前者以意志论为法理基础,后者以体现为中华民族共同体的连属论为法理基础,连属关系可为识别隐性“台独”提供重要判准。司法机构对意志论和连属论的结合运用,正如《关于依法惩治“台独”顽固分子分裂国家、煽动分裂国家犯罪的意见》列举和打击的四种“台独”行为,有助于积极预防和惩戒各种显性与隐性“台独”行为,为实现国家统一贡献法治力量。

浅析英语口语隐性课程的“显性控制”

隐性课程是显性课程的拓展和延伸,是学校教育不可或缺的部分。英语口语隐性课程的"显性控制",对学生英语口语水平的提高至关重要,对课程组织者提出了更高的要求。本文介绍了英语口语隐性课程的研究背景,涵义和特点,阐述了对其研究的重要性,着重强调如何在教学过程中对英语口语隐性因素加以"显性"控制,为学生创造一个良好的英语口语学习环境,以提高学习兴趣,激发学习热情,达到学习目的。

外语教学的“显性法”与“隐性法”及其应用

“显性法”与“隐性法”曾为相互对立的两种外语教学法。二者从对立到融合再到互补的发展过程 ,反映了人们对外语教学本质认识的不断深化和教学理论的日臻完善。本文追溯了显性法与隐性法的发展历史 ,对二者的基本原理及应用技巧进行了分析对比 ,并就实际应用问题提出了几点见解。

基于生物科学史的“显性”科学本质教学--以“植物生长素的发现过程”为例

以“植物生长素的发现过程”为例,利用生物科学史进行科学本质的“显性”教学,引导学生运用假说一演绎法分析植物向光生长的原因。学生在感受和体验科学家的探索过程中分析科学知识的形成,萃取科学方法的精华,感悟科学精神的启迪,从而更好地理解科学的本质,提高生物学学科核心素养。

再探电视广告费“显性转移支付”

针对电视广告费"隐性转移支付"的模糊笼统等缺陷,有的学者提出了"显性转移支付"的理念和设想。从电视媒体的特性和受众心理特点考虑,"显性转移支付"容易导致受众以消极心态接触电视媒体和广告,受众的休闲自在心理需求受到约束,媒体措施与受众的动机发生错位,是不切实际的。而"隐性转移支付"、"显性支付"和二者结合的支付方式仍然适用。

Strength and plasticity improvement induced by strong grain refinement after Zr alloying in selective laser-melted AlSiMg1.4 alloy

In order to enhance the mechanical properties of the selective laser-melted(SLM) high-Mg content AlSiMg1.4 alloy,the Zr element was introduced.The influence of Zr alloying on the processability,microstructure,and mechanical properties of the alloy was systematically investigated through performing microstructure analysis and tensile testing.It was demonstrated that the SLM-fabricated AlSiMg1.4-Zr alloy exhibited high process stability with a relative density of over 99.5% at various process parameters.Besides,the strong grain refinement induced by the primary Al3Zr particle during the melt solidification process simultaneously enhanced both the strength and plasticity of the alloy.The values for the yield strength,ultimate tensile strength,and elongation of the SLM-fabricated AlSiMg1.4-Zr were(343±3) MPa,(485±4) MPa,and(10.2±0.2)%,respectively,demonstrating good strengthplasticity synergy in comparison to the AlSiMg1.4 and other Al-Si-based alloys fabricated by SLM.

Damage characteristics of Cu−Cr−Zr alloy rail of electromagnetic railgun after simulated launch

The damage characteristics of different speed sections of Cu−Cr−Zr alloy rail after simulated launch were studied.The microstructure,morphologies and properties of samples were investigated by using XRD,XPS,EBSD,SEM,hardness test,electrochemical test and DSC techniques.It was found that deposition layers were formed on the surfaces of the simulated launch samples.The thickness and surface roughness of these deposition layers increased with increasing the heat effect,suggesting a launch speed dependent damage degree of the arc ablation.The hardness variation of samples is attributed to the effects of the deposition layer and deformation hardening.The surface deposition layer affects corrosion resistance and crystalline characteristics,leading to changes in subsequent service performances.Additionally,the surface texture and plastic deformation ability of the samples are related to the recrystallization degree and deformation grain amount.

Evolution of mechanical properties,localized corrosion resistance and microstructure of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging

The evolution of mechanical properties,localized corrosion resistance of a high purity Al-Zn-Mg-Cu alloy during non-isothermal aging(NIA)was investigated by hardness test,electrical conductivity test,tensile test,intergranular corrosion test,exfoliation corrosion test,slow strain rate tensile test and electrochemical test,and the mechanism has been discussed based on microstructure examination by optical microscopy,electron back scattered diffraction,scanning electron microscopy and scanning transmission electron microscopy.The NIA treatment includes a heating stage from 40℃to 180℃with a rate of 20℃/h and a cooling stage from 180℃to 40℃with a rate of 10℃/h.The results show that the hardness and strength increase rapidly during the heating stage of NIA since the increasing temperature favors the nucleation and the growth of strengthening precipitates and promotes the transformation of Guinier-Preston(GPI)zones toη'phase.During the cooling stage,the sizes ofη'phase increase with a little change in the number density,leading to a further slight increase of the hardness and strength.As NIA proceeds,the corroded morphology in the alloy changes from a layering feature to a wavy feature,the maximum corrosion depth decreases,and the reason has been analyzed based on the microstructural and microchemical feature of precipitates at grain boundaries and subgrain boundaries.

Phase transformation in titanium alloys:A review

Due to a series of exceptional properties,titanium and titanium alloys have received extensive attention in recent years.Different from other alloy systems,there are two allotropes and a sequence of metastable phases in titanium alloys.By summarizing the recent investigations,the phase transformation processes corresponding to the common phases and also some less reported phases are reviewed.For the phase transformation only involvingαandβphases,it can be divided intoβ→αtransformation and a reverse transformation.The former one has been demonstrated from the orientation relationship betweenαandβphases and the regulation ofαmorphology.For the latter transformation,the role of the stress has been discussed.In terms of the metastable phases,the mechanisms of phase formation and their effects on microstructure and mechanical properties have been discussed.Finally,some suggestions about the development of titanium alloys have been proposed.

Microstructure and ablation behavior of Zr-based ultra-high-temperature gradient composites

To obtain high-performance Zr-based ultra-high-temperature composites,Zr-based ultra-high-temperature gradient composites were prepared by changing the laying method of the infiltrant via reactive melt infiltration.The effects of different infiltrant laying methods on the microstructure and ablative properties of Zr-based ultrahigh-temperature gradient composites were investigated.The results showed that the gradient structure of the Zr-based ultrahigh-temperature gradient composites differed when the composition ratio of the infiltrant was changed.When the thicknesses of the Zr/Mo/Si layers were 6/4/12 mm and 8/2/12 mm,the SiMoZrC solid solution content in the samples increased and decreased along the infiltration direction,respectively.The gradient samples were ablated in an oxyacetylene flame at 3000°C for 40 s.The ablation resistance of the sample was the highest when the infiltrant was a powder and the thickness of the Zr/Mo/Si layer was 6/4/12 mm.

Effect of annealing temperature on microstructure and mechanical properties of Mg-Zn-Zr-Nd alloy with large final rolling deformation

In this study,the Mg-3Zn-0.5Zr-χNd(χ=0,0.6)alloys were subjected to final rolling treatment with large deformation of 50%.The impact of annealing temperatures on the microstructure and mechanical properties was investigated.The rolled Mg-3Zn-0.5Zr-0.6Nd alloy exhibited an ultimate tensile strength of 386 MPa,a yield strength of 361 MPa,and an elongation of 7.1%.Annealing at different temperatures resulted in reduced strength and obviously increased elongation for both alloys.Optimal mechanical properties for the Mg-3Zn-0.5Zr-0.6Nd alloy were achieved after annealing at 200℃,with an ultimate tensile strength of 287 MPa,a yield strength of 235 MPa,and an elongation of 26.1%.The numerous deformed microstructures,twins,and precipitated phases in the rolled alloy could impede the deformation at room temperature and increase the work hardening rate.After annealing,a decrease in the work hardening effect and an increase in the dynamic recovery effect were obtained due to the formation of fine equiaxed grains,and the increased volume fraction of precipitated phases,which significantly improved the elongation of the alloy.Additionally,the addition of Nd element could enhance the annealing recrystallization rate,reduce the Schmid factor difference between basal and prismatic slip systems,facilitate multi-system slip initiation and improve the alloy plasticity.

Damping properties and mechanism of aluminum matrix composites reinforced with glass cenospheres

The damping properties were improved by preparing Al matrix composites reinforced with glass cenospheres through the pressure infiltration method.Transmission electron microscopy and scanning electron microscopy were employed to characterize the microstructure of the composites.The low-frequency damping properties were examined by using a dynamic mechanical thermal analyzer,aiming at exploring the changing trend of damping capacity with strain,temperature,and frequency.The findings demonstrated that the damping value rose as temperature and strain increased,with a maximum value of 0.15.Additionally,the damping value decreased when the frequency increased.Dislocation damping under strain and interfacial damping under temperature served as the two primary damping mechanisms.The increase in the density of dislocation strong pinning points following heat treatment reduced the damping value,which was attributed to the heat treatment enhancement of the interfacial bonding force of the composites.

Effect of cold rolling deformation on microstructure evolution and mechanical properties of spray formed Al−Zn−Mg−Cu−Cr alloys

The impact of cold rolling deformation,which was introduced after solid solution and before aging treatment,on microstructure evolution and mechanical properties of the as-extruded spray formed Al−9.8Zn−2.3Mg−1.73Cu−0.13Cr(wt.%)alloy,was investigated.SEM,TEM,and EBSD were used to analyze the microstructures,and tensile tests were conducted to assess mechanical properties.The results indicate that the D1-T6 sample,subjected to 25%cold rolling deformation,exhibits finer grains(3.35μm)compared to the D0-T6 sample(grain size of 4.23μm)without cold rolling.Cold rolling refines the grains that grow in solution treatment.Due to the combined effects of finer and more dispersed precipitates,higher dislocation density and smaller grains,the yield strength and ultimate tensile strength of the D1-T6 sample can reach 663 and 737 MPa,respectively.In comparison to the as-extruded and D0-T6 samples,the yield strength of the D1-T6 sample increases by 415 and 92 MPa,respectively.

Microstructural evolution and deformation mechanisms of superplastic aluminium alloys:A review

Aluminium alloy is one of the earliest and most widely used superplastic materials.The objective of this work is to review the scientific advances in superplastic Al alloys.Particularly,the emphasis is placed on the microstructural evolution and deformation mechanisms of Al alloys during superplastic deformation.The evolution of grain structure,texture,secondary phase,and cavities during superplastic flow in typical superplastic Al alloys is discussed in detail.The quantitative evaluation of different deformation mechanisms based on the focus ion beam(FIB)-assisted surface study provides new insights into the superplasticity of Al alloys.The main features,such as grain boundary sliding,intragranular dislocation slip,and diffusion creep can be observed intuitively and analyzed quantitatively.This study provides some reference for the research of superplastic deformation mechanism and the development of superplastic Al alloys.