Highly Ordered Superlattices from Self-assembly of Fe3O4 Nanocrystals

The nano materials often exhibit very interesting electrical, optical, magnetic, and chemical properties, which can not be achieved by their bulk counterparts. The development of uniform nanometer sized particles has been intensively pursued because of their technological and fundamental scientific importance. It is significant that nanostructured materials can be controllably assembled into the required geometry onto substrates, becoming the basis of the next generation of components and devices. The development of new methods and strategies for organizing the nanoparticle basic building blocks into the desired structures is required. Superlattices made from these building blocks give us the opportunity to study not only the properties of the individual building blocks, but also collective effects. The superparamagnetic iron oxide nanocrystals（NCs） have been used in the fields of bio-medicine, ferrofluids, refrigeration system, catalysis,     

Ultrastable Surface-Dominated Pseudocapacitive Potassium Storage Enabled by Edge-Enriched N-Doped Porous Carbon Nanosheets

The development of ultrastable carbon materials for potassium storage poses key limitations caused by the huge volume variation and sluggish kinetics. Nitrogen-enriched porous carbons have recently emerged as promising candidates for this application; however, rational control over nitrogen doping is needed to further suppress the long-term capacity fading. Here we propose a strategy based on pyrolysis–etching of a pyridine-coordinated polymer for deliberate manipulation of edge-nitrogen doping and specific spatial distribution in amorphous high-surface-area carbons; the obtained material shows an edge-nitrogen content of up to 9.34 at %, richer N distribution inside the material, and high surface area of 616 m² g⁻¹ under a cost-effective low-temperature carbonization. The optimized carbon delivers unprecedented K-storage stability over 6000 cycles with negligible capacity decay (252 mA h g⁻¹ after 4 months at 1 A g⁻¹), rarely reported for potassium storage.     

Blue-to-transmissive electrochromic poly(2,3-dimethyl-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT-Me2) with improved optical contrast

Journal of Solid State Electrochemistry - A novel electrochromic polymer poly(2,3-dimethyl-2,3-dihydrothieno[3,4-b][1,4]dioxine) (PEDOT-Me2) based on 3,4-ethylenedioxythiophene (EDOT) with...     

大学物理实验数据分析与处理软件的研究与实现

本文针对开发计算机数据分析与处理软件来提高实验效率,保证实验教学的质量,介绍了软件的主要功能以及软件开发中遇到的一些问题和解决办法     

可控硅外特性的研究

开发和推广可控硅特性研究的物理实验,意在启发学生对物理实验的趣味性和思考方法,让学生在实验课中根据观察到的现象和实验数据在实验课后进行分析,最后判断并得出结论.     

TPU增韧MABS的研究

利用双螺杆挤出机制备聚氨酯和甲基丙烯酸甲酯—丙烯腈-丁二烯-苯乙烯树脂熔融共混物(合金).研究TPU的类型以及含量对TPU/MABS合金的透光率、力学性能和缺口冲击强度影响.结果表明:TPU/MABS合金可以保持较好透明性,随TPU含量的增加,合金材料的拉伸强度和弯曲模量逐渐降低,但是合金材料的冲击强度得到明显提高.扫...     

有特色的选修课教材——《色彩与微观世界》

颜色是物质的基本属性之一,是物质微观结构的宏观表现。围绕颜色这一广泛而生动的话题,化学工业出版社于2004年9月出版的《色彩与微观世界》一书较系统地论述了颜色与物质微观结构理论之间的关系。本书是编著者金增瑗在首都师范大学开设色彩与物质结构选修课9年后精心完成的。全书共9章:第1章,颜色的基本理论。第2章,物质的结构状态与光学颜色。以露珠彩虹、蓝天白云以及多种宝石的彩晕为例,剖析了色散、散射、干涉、衍射等物理效应产生的颜色与物质的微观结构的特有关系。第3章,原子的结构状态与简单激发产生的颜色。介绍了黑体辐射与彩色…     

Sn/Al2O3催化剂结构与选择性催化还原NO性能

以不同沉淀剂和铝盐与SnCl4共沉淀制备了Sn/Al2O3催化剂.考察了催化剂在富氧条件下催化丙烯选择性还原NO的性能,借助于X射线衍射(XRD)、扫描电镜(SEM)、N2吸附-脱附、吡啶吸附红外光谱(Py-IR)和程序升温还原(TPR)等方法研究了催化剂性能与结构的关系.发现以NH3.H2O和NH4HCO3为沉淀剂、NH4Al(SO4)2为铝盐制备的Sn/Al2O3催化剂催化活性最高,NO转化率达90.9%,最佳催化活性温度为350℃.该催化剂的比表面积为254 m2/g,孔体积为0.878 cm3/g,孔径分布曲线在3~8 nm出现双峰,Sn物种主要以晶态SnO2存在,且表面Lewis酸酸量增加.     

高居里温度铁电单晶PIN-PT的机电性能

弛豫铁电单晶Pb(In_1/2Nb_1/2)O₃-PbTiO₃(PIN-PT)相较于常用的Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃(PMN-PT)具有更高的居里温度,在高稳定性、高性能的传感器、换能器方面具有应用前景。本工作采用谐振法研究了[001]方向极化的0.66PIN-0.34PT铁电单晶的全矩阵机电性能参数。0.66PIN-0.34PT 单晶的三方-四方相变温度(T_RT)约为160 ℃,居里温度(T_C)约为260 ℃,室温压电系数d₃₃、d₃₁、d₁₅分别为1 340 pC/N、-780 pC/N、321 pC/N,介电常数ε^T₃₃、ε^S₃₃、ε^T₁₁、ε^S₁₁分别为2 700、905、2 210、1 927,机电耦合系数 k₃₃、k₃₁、k₁₅、k_t分别为 87%、58%、38%、61%。其纵向压电常数(d₃₃)和纵向机电耦合系数(k₃₃)小于 PMN-PT 单晶,但是横向压电性能(d₃₁)和剪切压电性能(d₁₅)都略高于PMN-PT单晶。另外,研究了机电耦合性能随温度的变化趋势,发现0.66PIN-0.34PT单晶在150 ℃以下有较好的温度稳定性。     

Syntheses,Crystal Structures and Fluorescence Properties of Three Complexes Based on 2,2'-Quinoline-4,4'-dicarboxylic Ligands

Crystallography Reports - Three new coordination complexes, [Mn(L)(H2O)4⋅(H2O)3]2 (1), [Mg(L)(H2O)4⋅(H2O)3]2 (2), and [Cu(L)(phen)⋅(H2O)4]2 (3) (H2L =...