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离子液体插层导致的MoTe2,WTe2拓扑及超导性质的双重调控 认领
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作者 张浩雄 阿瓦拜克力·肉苏里 +10 位作者 沈胜春 张柯楠 王冲 罗来鹏 王吉章 吴扬 徐勇 段文晖 姚宏 于浦 周树云 《科学通报:英文版》 SCIE EI CSCD 2020年第3期188-193,共6页
使拓扑材料具有超导电性是实现拓扑超导的一个重要途径.Td相的MoTe2和WTe2不仅具有新颖的拓扑性质,其物理特性紧密依赖于层间耦合作用的强弱.本工作通过一种新颖的实验方法,在MoTe2和WTe2单晶样品中插入离子液体的有机阳离子,制备出层... 使拓扑材料具有超导电性是实现拓扑超导的一个重要途径.Td相的MoTe2和WTe2不仅具有新颖的拓扑性质,其物理特性紧密依赖于层间耦合作用的强弱.本工作通过一种新颖的实验方法,在MoTe2和WTe2单晶样品中插入离子液体的有机阳离子,制备出层间距可调、性质稳定且超导增强的有机-无机复合样品.插层后的MoTe2样品属于三维弱拓扑绝缘体,超导转变温度从0.25 K大幅提高到了7 K;而插层后WTe2的超导转变温度提高到了具有量子自旋霍尔效应的单层WTe2的2.8倍(2.3 K).本工作通过插层离子液体的有机阳离子到MoTe2和WTe2样品中,实现对其拓扑及超导性质的双层调控,为后续研究拓扑超导、实现马约拉纳零模提供了新的机遇.另外,这一新方法具有普适性,可以广泛适用于各种层状材料,这将为在层状材料中探索和实现更多新颖物理性质提供便利. 展开更多
关键词 INTERCALATION of organic cation Topological MATERIALS Weyl SEMIMETALS MoTe2 and WTe2 Ionic liquids CATIONS ORGANIC-INORGANIC hybrid MATERIALS Enhanced superconductivity
Encapsulation in the Food Industry: A Brief Historical Overview to Recent Developments 认领
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作者 Yakindra Prasad Timilsena Md. Amdadul Haque Benu Adhikari 《食品与营养科学(英文)》 2020年第6期481-508,共28页
Encapsulation in food industry serves several functions including masking of undesirable color/flavor/taste, preservation of unstable constituents, incor<span style="font-family:Verdana;">poration of a... Encapsulation in food industry serves several functions including masking of undesirable color/flavor/taste, preservation of unstable constituents, incor<span style="font-family:Verdana;">poration of additional functional and nutritional components and site-specific</span><span style="font-family:Verdana;"> release of encapsulated ingredients at a controlled time and rate. The knowledge of microencapsulation in other sectors like pharmaceutical industry is well advanced;however, more understanding is required to harvest the maximum benefits from food industry. This paper started with highlighting the gradual progress of microencapsulation process in food industry and ended up with some invaluable suggestions for future works. In the body, the paper reviews the major techniques of food encapsulation, choices of coating materials and the performance measurement methods of food encapsulation. Future trends, scopes and aspects of microencapsulation process in food manufacturing sector are also presented as the necessary recommendations for future researches. The article would help the microencapsulated food manufacturers to choose the target oriented encapsulates and suitable encapsulation technique.</span> 展开更多
关键词 MICROENCAPSULATION Shell Materials Core Materials Encapsulation Techniques Encapsulation Efficiency Controlled Release
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生物可吸收材料特点及在骨科中的应用 认领
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作者 李晏乐 岳肖华 +4 位作者 聂真 张峻玮 李朝辉 聂伟志 姜红江 《中国组织工程研究》 CAS 北大核心 2021年第16期2612-2617,共6页
背景:生物可吸收材料在十几年的临床应用中展现了明显优势,在生物医学多个领域中得到广泛应用。目的:综述现阶段生物可吸收材料的特点及其在骨科中的应用进展。方法:应用计算机检索万方数据库、CNKI数据库、维普数据库和PubMed数据库中... 背景:生物可吸收材料在十几年的临床应用中展现了明显优势,在生物医学多个领域中得到广泛应用。目的:综述现阶段生物可吸收材料的特点及其在骨科中的应用进展。方法:应用计算机检索万方数据库、CNKI数据库、维普数据库和PubMed数据库中的相关文献,中文检索词为"生物可吸收材料、生物可吸收金属材料、生物可吸收无机材料、高分子材料、生物复合材料",英文检索词为"Bioabsorbable/Bioabsorbable material、Metal material、Polymer material、Biocomposites"。结果与结论:可吸收金属材料具有较好的机械性能;聚合物材料腐蚀机制明确,可以预测其在体内外腐蚀行为和腐蚀速率,但承重性能不如可吸收金属材料;生物陶瓷材料经过一定处理后具有良好的生物相容性、骨传导性及骨结合性,但脆性大且不易成型;生物复合材料不仅兼具组分材料的性质,还能获得单一组分材料所不具有的新性能,具有广泛的应用的前景。 展开更多
关键词 材料 生物可吸收 高分子材料 生物复合材料 生物相容性 骨组织工程 综述
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Materials Studio软件在材料科学基础教学中的应用 认领
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作者 燕云程 《广东化工》 CAS 2020年第12期253-254,共2页
为了解决材料科学基础中晶体学和键合理论教学中存在的知识抽象、不易讲解的问题,采用Materials Studio软件的Visualizer模块和Castep程序包结合相关问题分别建立晶体空间结构和计算晶体的差分电荷密度图辅助材料科学基础教学。结果表... 为了解决材料科学基础中晶体学和键合理论教学中存在的知识抽象、不易讲解的问题,采用Materials Studio软件的Visualizer模块和Castep程序包结合相关问题分别建立晶体空间结构和计算晶体的差分电荷密度图辅助材料科学基础教学。结果表明通过Materials Studio软件建立的晶体空间结构和计算所得差分电荷密度图生动形象,能够帮助学生更深入地理解晶体学和键合理论的相关知识,达到良好的教学效果。为学生深入地学习材料科学基础打下坚实的基础。 展开更多
关键词 Materials Studio 材料科学基础 晶体学 键合理论 教学
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文章速递Progress on multiphase layered transition metal oxide cathodes of sodium ion batteries 认领
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作者 Qi Wang Shiyong Chu Shaohua Guo 《中国化学快报:英文版》 SCIE CAS CSCD 2020年第9期2167-2176,共10页
As one of the most promising secondary batteries in large-scale energy storage,sodium ion batteries(SIBs) have attracted wide attention due to the abundant raw materials and low cost.Layered transition metal oxides ar... As one of the most promising secondary batteries in large-scale energy storage,sodium ion batteries(SIBs) have attracted wide attention due to the abundant raw materials and low cost.Layered transition metal oxides are one kind of popular cathode material candidates because of its easy synthesis and large theoretical specific capacity.Yet,the most common P2 and O3 phases show distinct structural characteristics respectively.O3 phase can serve as a sodium reservoir,but it usually suffers from serious phase transition and sluggish kinetics.For the P2 phase,it allows the fast sodium ion migration in the bulk and the structure can maintain stable,but it is lack of sodium,showing a great negative effect on Coulombic efficiency in full cell.Thus,single phase structure almost cannot achieve satisfied comprehensive sodium storage performances.Under these circumstances,exploiting novel multiphase cathodes showing synergetic effect may give solution to these problems.In this review,we summarize the recent development of multiphase layered transition metal oxide cathodes of SIBs,analyze the mechanism and prospect the future potential research directions. 展开更多
关键词 Sodium ion batteries Cathodes Layered transition metal oxides Biphase materials Triphase materials
文章速递新型材料在汽车上的应用 认领
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作者 翁俊强 《时代汽车》 2020年第22期11-12,共2页
汽车作为一种交通工具,至今也有一百多年,随着生产技术的发展汽车日渐成为人们活动中不可缺少的重要组成部分。而汽车产业的进步发展与其材料的发展是不能分开的,汽车材料的发展能更好促进汽车产业的向前推进;而汽车的进步也会相应的带... 汽车作为一种交通工具,至今也有一百多年,随着生产技术的发展汽车日渐成为人们活动中不可缺少的重要组成部分。而汽车产业的进步发展与其材料的发展是不能分开的,汽车材料的发展能更好促进汽车产业的向前推进;而汽车的进步也会相应的带动一系列相关产业发展,尤其是带动与汽车相关的材料制造厂商群体的业务发展。近几十年来,人类的科技发展飞快,能源的消耗也相较以往大大增加;然而可持续发展的理念已成为全球国家探讨的发展的方向。如何让资源更加合理的得到运用,如何让人类能够与自然和睦的相处,如何促进新型材料的进一步发展,制造出更加节省能源,废气排放量更加低的新型节能汽车,又得以减少环境的污染。现在人们都倾向追求汽车有更好的舒适性,高安全性,高智能化,这些特征都将成为未来汽车产业发展的方向,都为汽车材料的发展制造开阔更加广阔的发展天空。 展开更多
关键词 材料 发展 新型材料 追求 高智能化
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文章速递Comparative Dimensional and Microscopic Analysis of the Strength and Hardness of Internal Fixation Plates 认领
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作者 Victor Tieghi Neto Eduardo Stedile Fiamoncini +3 位作者 Matheus Falsarelli Ferreira Danilo Luiz Flumignan Luis Geraldo Vaz Eduardo Sanches Gonçales 《口腔学期刊(英文)》 2020年第10期310-320,共11页
The fixation stability achieved with the use of plates and screws in oral and maxillofacial surgery is a decisive factor in treatment success. The mechanical and structural properties of the internal fixation material... The fixation stability achieved with the use of plates and screws in oral and maxillofacial surgery is a decisive factor in treatment success. The mechanical and structural properties of the internal fixation materials have direct influence on the dimensional stability and resistance of a fixation system, thus influencing treatment outcomes. This study proposed to analyze the dimensional and resistance patterns of titanium plates used for obtaining stable fix<span style="font-family:Verdana;">ation in orthognathic surgery and craniofacial trauma. For this study, 30 conventional 2.0</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">mm straight four hole plates with bridge from three brands commercialized in Brazil, were subjected to macroscopic, microscopic, strength and hardness analysis. The dimensional measurements were performed using a digital caliper. Energy-dispersive X-ray spectroscopy analysis was performed by scanning electron microscopy to analyze the chemical composition of the samples. The mechanical resistance tests were performed with a universal testing machine. The samples were then submitted to Vickers hardness analysis, complying with the standards of ASTM E92. The data collected from the dimensional study was submitted to statistical analysis of the coefficient of variation, while the values obtained during the mechanical tests were analyzed by variance (ANOVA) and Tukey’s test (p <</span><span style="font-family:Verdana;"> </span><span style="font-family:Verdana;">0.05). The sample groups presented different performances in resistance, hardness, size and surface, even though they were reported to be chemically similar compounds that allowed us to conclude the plates from Group 2 were more resistant than groups 1 and 3.</span> 展开更多
关键词 Fracture Fixation Internal Biocompatible Materials Compressive Strength
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Egg shell waste as an activation agent for the manufacture of porous carbon 认领
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作者 Yawei Shi Guozhu Liu +1 位作者 Mingde Li Liang Wang 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2020年第3期896-900,共5页
Egg shell waste was used as an activation agent directly for the manufacture of a biomass-derived porous carbon,which possessed a surface area of 626 m2·g-1 and was rich in nitrogen,sulfur and oxygen functionalit... Egg shell waste was used as an activation agent directly for the manufacture of a biomass-derived porous carbon,which possessed a surface area of 626 m2·g-1 and was rich in nitrogen,sulfur and oxygen functionalities.The activation mechanism was proposed,and the carbon showed its potential to act as an adsorbent for the adsorptive removal of various contaminants from both aqueous and non-aqueous solutions,possessing maximum adsorption capacities of 195.9,185.1,125.5 and 44.6 mg·g-1 for sulfamethoxazole,methyl orange,diclofenac sodium and dibenzothiophene,respectively.Through the utilization of egg shell waste as a sustainable activation agent,this work may help to make the widely applied biomass-derived porous carbons more economical and ecological. 展开更多
关键词 Carbon materials Porous materials Egg shell Activation agent BIOMASS
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光驱动二维水平同质p-n结及其在光电互联电路中的应用 认领
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作者 李东 朱晨光 +8 位作者 刘华伟 孙兴霞 郑弼元 刘莹 刘勇 王兴旺 朱小莉 王笑 潘安练 《科学通报:英文版》 SCIE EI CSCD 2020年第4期293-299,共7页
实现以光作为输入来控制器件行为的光驱动器件是现代光电互联电路研究的重点之一.本文基于二维材料体系,创新性地利用光栅极代替普通场效应晶体管中的栅极,利用光代替栅极电压作为输入,用以驱动器件从电阻状态转变为p-n二极管状态.在所... 实现以光作为输入来控制器件行为的光驱动器件是现代光电互联电路研究的重点之一.本文基于二维材料体系,创新性地利用光栅极代替普通场效应晶体管中的栅极,利用光代替栅极电压作为输入,用以驱动器件从电阻状态转变为p-n二极管状态.在所制备的黑磷半光栅晶体管中,当无光照引入时,器件在电阻状态下工作,不具有整流;当引入光照后,由于半光栅极所产生的光生栅压效应,沟道层被定义于p-n二极管状态,表现出明显的整流行为和光伏特性.当撤掉光时,沟道层由二极管状态恢复至电阻状态,也进一步说明p-n结的形成依赖于光照的引入.也就是说,半光栅晶体管既可以利用光来形成p-n结,同时又可以把光转换为电,体现出"一体式"特点.该光控p-n结将会在新一代光电互联电路中找到一些新奇的应用. 展开更多
关键词 TWO-DIMENSIONAL materials Light-triggered DEVICE p-n DIODES Opto-electrical INTERCONNECTION CIRCUITS
可充电电池中具有空心结构的正极材料 认领
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作者 朱晓波 唐佳勇 +3 位作者 黄亨明 林同恩 罗彬 王连洲 《科学通报:英文版》 SCIE EI CSCD 2020年第6期496-512,M0004共18页
随着可充电电池应用的广泛应用,人们对可充电电池的性能(质量比容量、倍率性能和循环稳定性)提出了更高的要求.设计合成具有微纳米结构的电极材料是提升可充电电池电学性能的一个重要研究方向,其中空心结构设计因其有效性引起研究人员... 随着可充电电池应用的广泛应用,人们对可充电电池的性能(质量比容量、倍率性能和循环稳定性)提出了更高的要求.设计合成具有微纳米结构的电极材料是提升可充电电池电学性能的一个重要研究方向,其中空心结构设计因其有效性引起研究人员的重视.目前空心结构的应用主要集中在负极材料上,相比之下具有空心结构的正极材料因其较难的形貌控制以及较低的体积比容量,研究相对较少.本文总结了具有空心结构的正极材料在可充电电池,主要是在锂离子电池和钠离子电池中的应用,分析讨论了此类正极材料研究中取得的成绩以及存在的问题和挑战.由于空心结构具有更多的反应位点、利于电解液的渗透以及能缓解充放电过程中的体积变化,空心结构化能明显改进下一代高比容量正极材料(比如富锂层型材料、钒基氧化物、硅酸盐等)的电学性能.这些材料往往表现出较低的电子电导率、离子扩散系数和较高的体积变化率.我们相信通过精确控制空心结构的空间结构、开发低成本可放大的合成策略,空心结构能为未来的高性能正极材料提供较为实用化的解决方案. 展开更多
关键词 RECHARGEABLE BATTERIES CATHODE materials HOLLOW structures ELECTROCHEMICAL performance
Utilisation of Indigenous Ceramic Raw Materials for the Production of Water Closet 认领
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作者 Z. U. Elakhame Y. J. Obe +7 位作者 Y. L. Shuaib-Babata L. K. Bankole O. J. Omowunmi I. O. Ambali O. O. Akinsanya A. J. Unachukwu R. G. Adeyemo M. Ikusedun 《矿物质和材料特性和工程(英文)》 2020年第5期364-376,共13页
The fact is that Nigeria ceramic raw materials are underutilized as a result of inadequate information on the materials which limits the local production of water closet. The emphasis of this research was on the suita... The fact is that Nigeria ceramic raw materials are underutilized as a result of inadequate information on the materials which limits the local production of water closet. The emphasis of this research was on the suitability of the physio-chemical properties of the abundant locally sourced ceramic raw materials from South-west Nigeria. The selected locally sourced raw materials included: kaolin, feldspar, silica and ball clay. The Physical properties carried out on the specimens produced include chemical analysis, shrinkage, porosity, bulk density, modulus of rupture, plasticity and viscosity. The physical property tests were done in accordance with (ASTM C). Standard and the chemical composition were identified by AAS spectrometer. However, the ratio of kaolin, feldspar, quartz and ball clay was varied in five major formulation represented as A, B, C, D and E. The clay, kaolin, quartz and feldspar used in this study were found to belong to alumina-silicate group suitable for the production of standard water closet. The samples’ properties met the required standards;hence, the materials were found suitable for production of water closet of acceptable standards. Composition A specimen gives the most suitable proportions for the production of water closet at 40% of kaolin, 25% of feldspar, 10% of quartz and 25% of ball clay respectively. 展开更多
关键词 Ceramics Materials Characterization MOULD Slip-Cast Water-Closet
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Graphitic carbon nitride with different dimensionalities for energy and environmental applications 认领
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作者 Qiang Hao Guohua Jia +4 位作者 Wei Wei Ajayan Vinu Yuan Wang Hamidreza Arandiyan Bing-Jie Ni 《纳米研究:英文版》 SCIE EI CAS CSCD 2020年第1期18-37,共20页
As a metal-free semiconductor,graphitic carbon nitride(g-C3N4)has received extensive attention due to its high stability,nontoxicity,facile and low-cost synthesis,appropriate band gap in the visible spectral range and... As a metal-free semiconductor,graphitic carbon nitride(g-C3N4)has received extensive attention due to its high stability,nontoxicity,facile and low-cost synthesis,appropriate band gap in the visible spectral range and wide availability of resources.The dimensions of g-C3N4 can influence the regime of the confinement of electrons,and consequently,g-C3N4 with various dimensionalities shows different properties,making them available for many stimulating applications.Although there are some reviews focusing on the synthesis strategy and applications of g-C3N4,there is still a lack of comprehensive review that systemically summarises the synthesis and application of different dimensions of g-C3N4,which can provide an important theoretical and practical basis for the development of g-C3N4 with different dimensionalities and maximises their potential in diverse applications.By reviewing the latest progress of g-C3N4 studies,we aim to summarise the preparation of g-C3N4 with different dimensionalities using various structural engineering strategies,discuss the fundamental bottlenecks of currently existing methods and their solution strategies,and explore their applications in energy and environmental applications.Furthermore,it also puts forward the views on the future research direction of these unique materials. 展开更多
关键词 graphitic carbon nitride micro-nano structure energy functional materials environmental functional materials PHOTOCATALYST
地聚合物凝胶体系中N-A-S-H和C-A-S-H结构的分子模拟 认领 被引量:1
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作者 王晴 康升荣 +2 位作者 吴丽梅 唐宁 张强 《建筑材料学报》 EI CAS CSCD 北大核心 2020年第1期184-191,共8页
钙元素对地聚合物凝胶结构的形成影响显著,根据含钙量的不同可分为高钙体系(C-A-S-H)和无钙体系(N-A-S-H).基于Materials Studio软件,用Amorphous Cell(AC)模块构建了N-A-S-H和C-A-S-H凝胶结构模型.在Universal力场下,对2个凝胶结构模... 钙元素对地聚合物凝胶结构的形成影响显著,根据含钙量的不同可分为高钙体系(C-A-S-H)和无钙体系(N-A-S-H).基于Materials Studio软件,用Amorphous Cell(AC)模块构建了N-A-S-H和C-A-S-H凝胶结构模型.在Universal力场下,对2个凝胶结构模型的稳定性、动力学轨迹、微观表征及弹性模量进行了分子动力学模拟.结果表明,构建的N-A-S-H和C-A-S-H凝胶结构模拟值与试验值吻合较好.由于钙元素的存在,无定形态体系出现了向晶体转变的特征,并对地聚合物的力学性能产生正向增益. 展开更多
关键词 N-A-S-H凝胶 C-A-S-H凝胶 分子动力学模拟 Materials STUDIO软件
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分子模拟技术在新型催化剂设计中的应用 认领
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作者 梁坤 周军 +3 位作者 吴雷 宋永辉 田宇红 付义乐 《化工新型材料》 CAS CSCD 北大核心 2020年第2期41-45,49共6页
分子模拟技术能高效、便捷地研究催化材料的表面分子间微观作用机理、分子结构及性能等,为提升催化材料性能和优化制备工艺提供可靠的依据。分子模拟技术的应用不仅能极大地缩短催化材料的研发周期,而且有效控制了研发成本。Materials S... 分子模拟技术能高效、便捷地研究催化材料的表面分子间微观作用机理、分子结构及性能等,为提升催化材料性能和优化制备工艺提供可靠的依据。分子模拟技术的应用不仅能极大地缩短催化材料的研发周期,而且有效控制了研发成本。Materials Studio软件是应用最为广泛的分子模拟软件,可用于催化材料的能量、结构、力学和光学性能及热力学和动力学等方面的计算。首先综述了Materials Studio软件在材料科学领域的应用现状,再详细介绍了该软件在协助新型催化剂设计中的应用,最后,总结了分子模拟技术现存问题和在催化领域的应用前景。 展开更多
关键词 分子模拟 MATERIALS STUDIO软件 新型催化剂 设计与模拟
Assessment of the Current State of Qanibay al-Rammah Complex (908 AH/1502 AD), as a Procedure Precedes the Restoration Process 认领
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作者 Essam H. Mohamed 《地质学期刊(英文)》 2020年第1期71-91,共21页
An assessment should be made of the current state of the historic buildings before starting in any intervention procedures. Where, any procedures of conservation of the building must be outrun by a perfect diagnosis a... An assessment should be made of the current state of the historic buildings before starting in any intervention procedures. Where, any procedures of conservation of the building must be outrun by a perfect diagnosis according to the international conventions. Chemical, physical, mechanical properties and structural status are extremely important to give information about the current condition of Qanibay al-Rammah madrasa, which situated within Saladin square in Historic Cairo. This building has been affected by several deterioration factors since the construction and still suffering damage factors at the moment, which led to the occurrence of several damage aspects to the building, such as fissures in architectural elements, granular disintegration, loss of stone material, peeling of limestone surface, splitting in building material, the efflorescence of salts, pitting in limestone surface, black spots in stone surface, hard black crust, etc. The aim of this study is evaluation of the condition of Qanibay al-Rammah madrasa by two methods, firstly by different scientific techniques such as X-Ray Diffraction (XRD), EDX analytical methods, Scanning Electron Microscopy (SEM), Polarizing Light Microscopy (PLM), and Stereo Microscopy, and secondly by Numerical analysis based on 3D finite elements analysis to determine the critical places of the building. The followed methodology in this study allowed us to the assessment of the current status of the building by various scientific techniques to determine the real causes of damage, which must be taken into account during the intervention procedures. 展开更多
关键词 Madrasa of Qanibay al-Rammah The Current STATUS Building Materials Characteristics Structural Behavior SCIENTIFIC Techniques Numerical Analysis
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Synthesis of selenium-doped carbon from glucose:An efficient antibacterial material against Xcc 认领
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作者 Hongen Cao Yufan Yang +4 位作者 Xijun Chen Jian Liu Chao Chen Shuzhong Yuan Lei Yu 《中国化学快报:英文版》 SCIE CAS CSCD 2020年第7期1887-1889,共3页
Se/C as a novel carbon-based biomaterial was prepared by using cheap and abundant glucose as the carbon source.It was highly active and could well restrain Xanthomonas campestris pv.campestris(EC50=4.7403 μg/mL),a ve... Se/C as a novel carbon-based biomaterial was prepared by using cheap and abundant glucose as the carbon source.It was highly active and could well restrain Xanthomonas campestris pv.campestris(EC50=4.7403 μg/mL),a very harmful germ causing the devastating cabbage black rot disease and resulting in huge economic losses.As a type of carbon material insoluble in wate r,Se/C is bio-compatible and can adhere onto the leaves of the plants to allow a slow and sustained release of its efficacy,affording an efficient method for the cabbage black rot disease prevention and cure.This work as the first report on the bioactivity studies of Se/C significantly expands the application scopes of the selenium-containing materials and may draw continuous attentions from a broad field. 展开更多
关键词 Carbon materials BIOMATERIALS Amorphous materials SELENIUM Bioactivity Cabbage black rot disease
Materials Studio在固体物理课程分层教学中的应用 认领
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作者 张欣会 《教育教学论坛》 2020年第34期304-305,共2页
为了深化固体物理课程改革,适应学生发展和学习需求,我们对固体物理课程采用了分层教学模式,针对不同专业不同层次水平的学生进行不同模式的教学,因材施教。同时在固体物理课程教学过程中把Materials Studio软件引入课件制作、课堂演示... 为了深化固体物理课程改革,适应学生发展和学习需求,我们对固体物理课程采用了分层教学模式,针对不同专业不同层次水平的学生进行不同模式的教学,因材施教。同时在固体物理课程教学过程中把Materials Studio软件引入课件制作、课堂演示和课下练习环节中,可视化图形,可操作性学习过程,增强了学生对物理模型的理解,激发了学生深入探索的学习兴趣。 展开更多
关键词 固体物理 分层教学模式 Materials Studio
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Materials Studio应用于有机化学教学中培养探索性思维 认领
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作者 王群 王雪倩 +1 位作者 孙玉希 刘晓东 《化学教育(中英文)》 CAS 北大核心 2020年第4期92-98,共7页
将计算模拟软件Materials Studio与有机化学教学有机结合,首先教师传授模拟软件知识、使用原理及使用此软件解决实际科学问题的案例;然后学生熟悉软件,自行发现有机化学课程中的重难点及困惑;最后在教师的帮助及团队的协助下使用此软件... 将计算模拟软件Materials Studio与有机化学教学有机结合,首先教师传授模拟软件知识、使用原理及使用此软件解决实际科学问题的案例;然后学生熟悉软件,自行发现有机化学课程中的重难点及困惑;最后在教师的帮助及团队的协助下使用此软件解决科学问题。此种教学方法不仅增强了课堂教学的生动性,丰富了课堂教学内容,还提高了学生对立体结构的认知能力,加深了学生对反应机理的理解,更重要的是,学生的探索性思维能力也得到了很好地培养。 展开更多
关键词 计算模拟 MATERIALS STUDIO 有机化学教学 探索性思维
Challenges of the Use of Instructional Materials in Geography Classroom in Secondary School: Nepal 认领
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作者 Keshav Raj Dhakal 《地理研究(英文)》 2020年第3期36-39,共4页
Geography is an optional subject in the secondary schools in Nepal.This paper is an attempt to examine the challenges of using instructional materials in the geography classroom in community secondary schools in Kathm... Geography is an optional subject in the secondary schools in Nepal.This paper is an attempt to examine the challenges of using instructional materials in the geography classroom in community secondary schools in Kathmandu district of Bagmati Province.Geography teachers were selected by purposive sampling offering geography as an optional subject in secondary school.The semi structured interview method was used for data collection.The interviews were recorded on an audio recorder and transcribed.After collecting data,analysis of the data was made through the interpretations of the raw data by interpretative method.The results reveal that the challenges of using materials are non-availability of materials,laziness of the teachers,lack of skill and strategies,financial constraint,lack of appropriate materials in textbook,time constraint,lack of support from authority,lack of geography resource room etc.The remedies of the challenges of using materials are the organizing of training and workshop for teachers on how to use instructional materials,provision of funds by the authorities and government,regular supervision,the improvisation of the local materials and the provision of the various instructional materials which are necessary for teaching etc. 展开更多
关键词 Instructional materials Geography lesson Qualitative research Quality teaching Local materials
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Accelerated Carbonation Assessment of High-Volume Fly Ash Concrete 认领
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作者 Federico Aguayo Anthony Torres +1 位作者 Yoo-Jae Kim Omkar Thombare 《材料科学与化学工程(英文)》 2020年第3期23-38,共16页
The issue of concrete carbonation has gained importance in recent years due to the increase use in supplementary cementing materials (SCMs) in concrete mixtures. While there is general agreement that concrete carbonat... The issue of concrete carbonation has gained importance in recent years due to the increase use in supplementary cementing materials (SCMs) in concrete mixtures. While there is general agreement that concrete carbonation progresses at maximum at a relative humidity of about 60%, the rate may differ in the case of cements blended with SCMs, especially with high-volume fly ash replacements. In this study, the effect of high-volume fly ash concrete exposed to low ambient relative humidity (RH) conditions (57%) and accelerated carbonation (4% CO2) is investigated. Twenty-three concrete mixtures were produced varying in cementitious contents (310, 340, 370, and 400 kg/m3), water-to-cementitious materials ratio (0.45 and 0.50), and fly ash content (0%, 15%, 30%, and 50%) using a low and high-calcium fly ash. The specimens were allowed 1 and 7 days of moist curing and monitored for their carbonation rate and depth through phenolphthalein measurements up to 105 days of exposure. The accelerated carbonation test results indicated that increasing the addition of fly ash also led to increasing the depth of carbonation. Mixtures incorporating high-calcium fly ash were also observed to be more resistant against carbonation than low-calcium fly ash due to the higher calcium oxide (CaO) content. However, mixtures incorporating high-volume additions (50%) specimens were fully carbonated regardless of the type of fly ash used. It was evident that the increase in the duration of moist curing from 1 day to 7 days had a positive effect, reducing the carbonation depth for both plain and blended fly ash concrete mixes, however, this effect was minimal in high-volume fly ash mixtures. The results demonstrated that the water-to-cementitious ratio (W/CM) had a more dramatic impact on carbonation resistance than the curing age for mixtures incorporating 30% or less fly ash replacement, whereas those mixtures incorporating 50% showed minor differences regardless of curing age or W/CM. Based on the compressive strength results, carbonation 展开更多
关键词 ACCELERATED CARBONATION FLY ASH Concrete Relative Humidity High-Volume FLY ASH Supplementary Cementitious Materials
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