Results 31 to 40 of about 12,710 (166)

Synthesis and properties of YAG:Ce3+ and YAGG:Ce3+ phosphors and transparent ceramics [PDF]

open access: yes, 2016
由于白光LED具有高效、环保、寿命长等优异性能,其被认为是继白炽灯和荧光灯之后的下一代照明光源。在白光LED中,荧光材料起着光转换的作用,是一种非常关键的材料。本论文针对YAG:Ce3+荧光粉、YAG:Ce3+透明陶瓷以及YAGG:Ce3+荧光材料进行了制备和发光性能方面的研究,具体内容如下: (1)分别以CeF3和CeO2为铈源,采用固相反应制备了一系列YAG:Ce3+荧光粉。以CeF3为铈源在1350℃就能制备出纯相YAG:CeF3荧光粉,而以CeO2为铈源则需要在1450℃才能制备出纯相YAG ...
强耀春
core  

Bioinspired 3D‐Printed NiTi Metamaterials With Bivalve‐Like Crossed‐Lamellar Structures

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Metamaterials demonstrate unique mechanical properties and functional performance owing to their distinctive topological spatial structures. In this study, by mimicking the natural Saxidomus purpuratus shell, bioinspired crossed‐lamellar architectures with interlamellar apex angles ranging from 60° to 150° were designed and fabricated in NiTi ...
Yu Chen   +9 more
wiley   +1 more source

电子辐照原位研究超细颗粒石墨的微观结构演变

open access: yesHe jishu
石墨在熔盐堆中作为慢化剂和结构材料,长期受到高温和高通量的快中子辐照,内部产生大量点缺陷,这些缺陷会湮灭、扩散或团聚形成大的位错结构,改变石墨的微观结构,进而改变其宏观性能。然而,目前缺乏对其缺陷演化过程的统一认识。因此,研究核石墨在高温能量粒子辐照下的缺陷演化和微观结构变化具有重要意义。本文采用200 keV的电子束在室温至750 ℃下对NG-CT-50超细颗粒核石墨进行了原位电子辐照实验,在高分辨透射电子显微镜中观察其微观结构的动态变化和位错的演化过程。研究发现 ...
孙 义军, 汪 雪, 周 兴泰
doaj   +1 more source

Development and genetic mechanism of complex carbonate reservoir fractures: A case from the Zanarol Oilfield, Kazakhstan

open access: yesPetroleum Exploration and Development, 2010
By core observation and slice analysis, two types of fractures can be identified in reservoirs of Zanarol Oilfield, including macro-fractures and micro-fractures.
Zhao Lun   +5 more
doaj   +1 more source

探索物质微观结构的历史回顾——纪念夸克提出50周年 [PDF]

open access: yes, 2014
1964年盖尔曼和兹威格分别提出"基本粒子"由夸克或艾斯组成。至今,这一领域仍是粒子物理研究的前沿领域。经过50年的发展,夸克(艾斯)理论取得诸多辉煌成就 ...
刘金岩
core  

Cancellous Bone‐Like Sr‐Doped Hydroxyapatite/Gelatin Porous Scaffolds With Nanofibrous Architecture and Ion Release for Promoting Osteogenesis

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Constructing a porous scaffold with the essential features of natural cancellous bone, including structural architecture and biochemical cues, is one of the pivotal factors for effective bone regeneration. In this study, a biomimetic composite porous Gelatin fibrous scaffold (SrHA/Gelatin) incorporating ultralong strontium‐doped hydroxyapatite
Yin‐Chuan Wang   +8 more
wiley   +1 more source

金雀异黄素对人肝癌细胞SMMC-7721抑制作用的研究

open access: yesZhongguo shiyan zhenduanxue, 2006
目的研究金雀异黄素对人肝癌细胞SMMC-7721生长的影响。方法应用MTT法、流式细胞术和透射电镜超微结构观察分析金雀异黄素对SMMC-7721细胞生长的作用,细胞周期及形态学的影响。结果金雀异黄素明显抑制人肝癌细胞SMMC-7721的生长,G2/M期细胞增加。透射电镜超微结构观察发现金雀异黄素使肿瘤细胞超微结构改变。结论金雀异黄素可通过改变细胞的周期和超微结构而抑制人肝癌细胞生长。
田晓丰   +5 more
doaj  

Synthesis and Properties of Self-healing Polymers and Electrically Conductive Composites Based on Hydrogen-bonding [PDF]

open access: yes, 2015
通过模仿生物体自愈合的特性,人工合成可自行感知和修复损伤的聚合物材料是一项富有深远意义的研究。目前聚合物材料在加工和使用过程中容易受到各种外界因素的破坏并产生难以监测的微裂纹,而这些微裂纹正是材料性能退化的起点。作为一种新颖的智能仿生材料,自修复聚合物能够感知并修复这类损伤,避免材料受到进一步破坏,延长材料使用寿命,消除安全隐患,节约维修成本。然而,目前研究的自修复高分子材料大多为绝缘体,使得其在导电领域中的应用受到限制。随着导电高分子材料在电子器件、传感器、能源、信息、航空等领域的广泛应用 ...
谢婷婉
core  

Dual‐Function In Situ Ti3(Cu,Al)3O Reinforcement for Simultaneous Strengthening and CTE Reduction in Sapphire/TC4 Active‐Brazed Joints

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT The thermal expansion mismatch between sapphire and Ti‐6Al‐4V (TC4) alloy has traditionally limited the shear strength of ceramic‐metal joints to ≤ 170 MPa. In this study, active brazing with Ag‐35.25Cu‐1.75Ti (wt%) leads to the formation of a dual‐function microstructure, wherein uniformly dispersed submicron Ti3(Cu,Al)3O particles embedded ...
Hairui Liu   +13 more
wiley   +1 more source

热老化对变压器绝缘纸微观结构影响的实验研究

open access: yesGaoya dianqi, 2016
为了研究热老化应力对变压器绝缘纸微观结构的影响,以更准确地分析油纸绝缘机械强度和绝缘性能,文中对油浸纸试品进行加速热老化实验,获取不同老化程度的变压器绝缘纸试样。测量了绝缘纸试样的聚合度,采用扫描电镜观察绝缘纸试样的表面微观形貌,通过傅里叶变换红外光谱(FTIR)分析纤维素分子结构变化。分析结果表明,热老化对变压器绝缘纸微观纤维结构破坏显著,纤维细化,断裂增多,纤维分子结构及相关官能团数量变化明显。
王世强   +4 more
doaj  

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