三氧化钨纳米线的制备及其光催化性能     

邹文雅  刘国聪 《惠州大学学报》2013,(6):18-23

以Na2WO4·2H2O和HCl为原料,采用水热法合成了WO3,并用x射线粉末衍射（XRD）、扫描电镜（SEM）、紫外漫反射（uV—Vis）、电子能量分散谱（EDS）和激光拉曼光谱（Raman）测试手段对样品进行表征。测试结果表明,Na2SO4作为添加剂时水热合成的产物皆为六方相三氧化钨纳米线,其粗细和长短略有差异,不同浓度的Na2SO4对产品晶型和形貌无影响,但影响其晶粒尺寸,其中0．125MNa2SO4所得六方相WO3纳米线的尺寸最小,平均直径约为5nm,长度约为1um,并具有最佳的光催化活性,可见光（≥420nm）照射150min罗丹明B溶液后的降解率达96．01％。  相似文献   

光谱与色谱方法用于有机合成分析     

刘特于  王树信  胡芳  李志良 《湖南师范大学教育科学学报》1996,(2)

系统深入地研究了光谱与色谱方法用于有机合成分析，本文依据光谱与色谱方法发现传统合成过程中金属卟啉相互转化问题，并进行了深入探讨，从而改进了合成方法，取得良好结果。  相似文献   

对国家数学课程标准中"联系与综合"目标的认识     

黄翔 《教育学报》2001,(1):1-3

论述了义务教育阶段国家数学课程标准设立"联系与综合"目标的必要性与合理性,并对该部分设计的若干问题作了探讨.  相似文献   

以Ag作为构筑单元的二维配位聚合物的合成与表征     

宣亚文  谢东坡  谢红 《周口师范学院学报》2008,25(2):66-68

配住聚合物[Ag(L)2ClO4]是以N,N-(2-吡啶)-(4-吡啶甲基)胺和AgClO4为原料,通过水(溶剂)热法合成.X单晶结构解析显示N,N-(2-吡啶)-(4-吡啶甲基)胺通过2-吡啶和4-吡啶甲基的N原子桥联Ag,形成菱形网格,配体N,N-(2-吡啶)-(4-吡啶甲基)胺的两个苯环互相垂直,并以Ag和分子间氢键为中心.化合物晶体数据单斜晶系,C2/c空间群,晶胞参数a=0.848 31(6)nm,b=1.725 4(1)nm,c=1.669 9(1)nm,β=99.677(6)°.V=2.559 4(1)nm3.  相似文献   

化合物[HO-4,6-di-C(CH3)3-C6H2-2-CH2{(NCHCHN)CH2}]的合成与晶体结构     

黄海霞  王志国  王秀峰  黄宝美  张翼 《绵阳师范学院学报》2008,27(8)

根据文献合成4,6-^tBu2-1-（HO）C6H2CH2Cl;利用亲核取代反应合成了一种芳氧功能化的咪唑[HO-4,6-di—C（CH3）3-C6H2-2-CH2{（NCHCHN）CH2}]。芳氧功能化的咪唑通过元素分析,核磁和单晶衍射表征。晶体结构表明其晶体属单斜晶系,空间群为P2 1／e,化学式为C18H26N2O,晶胞参数为a=18．694（3）A,b=10．2501（15）A,c=9．1536（15）A,α（deg）=90deg,β（deg）=103．006（4）deg,γ（deg）=90deg,V（A^3）=1708．9（5）A^3,Z=4,最终R1=0．1160,wR2=0．2263．  相似文献   

香豆素-3-羧酸乙酯的水热合成和表征   总被引：5，自引：0，他引：5  

张甜 《洛阳师范学院学报》2008,27(2):59-60

利用水热反应,在无水乙醇介质中,以水杨醛为原料,二乙胺为催化剂,与有活泼亚甲基的丙二酸二乙酯发生反应,合成化合物香豆素-3-羧酸乙酯。经IR、1H NMR和元素分析,确认了其结构。  相似文献   

吡啶基苯并咪唑化合物的微波合成及荧光特性     

郭应臣  姚兴芝  闫家伟 《南阳师范学院学报》2008,7(12)

以邻苯二胺、吡啶甲酸为原料,多聚磷酸为催化剂和溶剂,经微波辐射合成了2-（3-吡啶基）苯并咪唑、2-（2-吡啶基）苯并咪唑。通过熔点、元素分析、IR和1H NMR对其纯度和结构进行表征,探讨了目标化合物在微波辐射下合成的工艺条件及荧光特性。  相似文献   

大数据时代大学生自主学习能力预测研究     

郝水侠  付敏 《教育技术导刊》2021,19(12):32-37

大数据时代知识增长速度呈指数级增长,提升大学生自主学习能力迫在眉睫。根据大学生自主学习能力调查问卷,利用马尔可夫链构建大学生自主学习能力预测模型,通过模糊综合评判法对大学生自主学习能力进行评估,并对实验结果进行分析比较,给出不同年级、不同性别以及学习动机对自主学习能力的影响,最后给出大学生提升自主学习能力的方法与建议。  相似文献   

教师专业化背景下新型教师的自我塑造     

方元山 《河南职业技术师范学院学报(职业教育版)》2005,(3):34-37

促进教师专业化发展已成为国际教师教育改革的趋势。新型教师的自我塑造就是要让自己成长为综合型教师、学习型教师、研究型教师、合作型教师和创新型教师。  相似文献   

Qualitative review synthesis: the relationship between inattention and academic achievement     

Sarah Anne Gray  Katherine Dueck  Maria Rogers  Rosemary Tannock 《Educational research; a review for teachers and all concerned with progress in education》2017,59(1):17-35

Background: A body of literature has emerged that links inattentive symptoms of attention deficit hyperactivity disorder (ADHD) to poor academic achievement. Major variation across studies renders conclusions about this relationship complex.

Purpose: This review will provide a qualitative synthesis of these studies that (1) use community samples and (2) examine inattention as a separate dimension from hyperactivity/impulsivity. The aim of this review is to ascertain whether the relationship documented between inattention and academic outcomes in ADHD also holds for the dimensional trait of inattention as manifest in non-clinical community samples of children and adolescents, taking into consideration both academic achievement and academic performance across age.

Design and methods: A comprehensive search was carried out using two databases. The PRISMA guidelines were used to report the search steps. The QUIPS tool was used to rate the quality of studies, followed by a best evidence synthesis to summarise these results.

Results: Out of 1748 citations found, 27 articles met the specific inclusion criteria. Results point to a strong effect according to the best evidence synthesis: 7 studies that have low risk of bias found that teacher-rated inattention is significantly predicative of poor academic achievement in community samples of children.

Conclusions: This review provides support for a consistent, negative relationship between classroom inattention as reported by teachers and both standardised academic test achievement and classroom performance outcomes for children in preschool (moderate evidence), elementary school and longitudinally from elementary to high school. The average relationship was stronger when classroom performance was measured, as compared to standardised achievement. However, the quantitative strength of relationship has not been confirmed with a meta-analysis due to heterogeneity and too few high-quality studies identified. Variance across the studies in terms of the strength of association suggests that other unexamined factors (e.g. cognitive function or motivation) may be contributing to this relationship. Implications for educators and clinicians who work within the school setting are discussed.  相似文献