检索结果-南通市图书馆

npj Computational Materials 2020年第1期6卷 892-898页

作者： Luo Yan Peng-Fei Liu Hengtao Li Yong Tang Junjie He xingyong huang Bao-Tian Wang Liujiang Zhou Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054P.R.China Institute of High Energy Physics Chinese Academy of Sciences(CAS)Beijing 100049China Key Laboratory of Advanced Technology of Materials(Ministry of Education) School of Physical Science and TechnologySouthwest Jiaotong UniversityChengdu 610031China School of Material Sciences and Engineering Xiangtan UniversityXiangtanHunan 411105China Bremen Center for computational Materials Science University of BremenAm Falturm 1Bremen 28359Germany

Atomically thin borophene has recently been synthesized experimentally,significantly enriching the boron chemistry and broadening the family of two-dimensional(2D)***,oxides of 2D materials have been widely investigated for nextgeneration electronic *** on the first-principles calculations,we predict the existence of the superconductivity in honeycomb borophene oxide(B_(2)O),which possesses a high stability and could be potentially prepared by intrinsically incorporating oxygen into the recently synthesized borophene.

关键词： materials stability superconductivity

Concentration quenching in transparent glass ceramics containing Er^(3+):NaYF_4 nanocrystals

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2012年第7期55卷 1148-1151页

作者： huang xingyong CHEN DaQin LIN Lin WANG ZheZhe WANG YuanSheng FENG ZhuoHong ZHENG ZhiQiang College of Physies and Energy Fujian Normal UniversityFuzhou 350007China Fujian Institute of Research on the Structure of Matter Chinese Aeademy of SciencesFuzhou 350002China

In this work, we have studied the concentration quenching in transparent glass ceramics containing Er^3＋：NaYF4 nanocrystals. For different concentrations, the emission spectra and decay curves of the ^4I/3/2 → ^4I15/2 emission were measured. The Er-concentration dependence of integrated intensity and lifetime of ^4I13/2→^4I15/2 emission are showed. With the increase of the Er^3＋ doping concentration, the 1.5 μm fluorescence emission first increases, then decreases, and the lifetime falls gradually. With 980 nm excitation, the efficiency of the energy transfer from Er^3＋ to quenching centers reaches 73.73% for the sample with 4 mol% Er^3＋. Meanwhile, owing to the relation of fluorescence integrated intensity and Er-concentration, a dipole-dipole quenching mechanism in the framework of a limited diffusion regime has been proved. Using the limited diffusion case, the critical concentration for quenching has been determined from a fitting equation of the lifetime and Er-concentration. The fit- ting result shows the critical concentration for quenching is higher than the values obtained in Er-doped different glass by an order of magnitude.

关键词： concentration quenching glass ceramics Er^3+ nanocrystals critical concentration

HfX2(X=Cl,Br,I)Monolayer and TypeⅡHeterostructures with Promising Photovoltaic Characteristics

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2020年第12期37卷 62-65页

作者： xingyong huang Liujiang Zhou Luo Yan You Wang Wei Zhang Xiumin Xie Qiang Xu Hai-Zhi Song Southwest Institute of Technical Physics Chengdu 610041China Faculty of Science Yibin UniversityYibin 644007China Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

Two-dimensional(2D)materials and their corresponding van der Waals(vd W)heterostructures are considered as promising candidates for highly efficient solar cell applications.A series of 2D HfX2(X=Cl,Br,I)monolayers are proposed,via first-principle *** vibrational phonon spectra and molecular dynamics simulation results indicate that HfX2 monolayers possess dynamical and thermodynamical ***,their electronic structure shows that their Heyd–Scuseria–Ernzerhof(HSE06)-based band values(1.033–1.475 eV)are suitable as donor systems for excitonic solar cells(XSCs).The material’s significant visible-light absorbing capability(~105 cm-1)and superior power conversion efficiency(~20%)are demonstrated by establishing a reasonable typeⅠvd W *** suggests the significant potential of HfX2 monolayers as a candidate material for XSCs.

关键词： stability. donor establishing

在线全文

学校读者我要写书评

暂无评论

读者权的成本问题思考:以信息费用为视角

图书馆杂志 2006年第5期25卷 28-32页

作者：黄星永湘潭大学图书馆湖南411105

在现实社会中,读者权利屡屡遭受侵害而得不到救济。造成此种原因有很多。本文从权利成本的角度出发,分析读者权利得不到及时有效救济的原因是权利的收益与权利的成本相比不相称造成的。文章最后指出只有降低读者权利成本,读者才能较好... 详细信息

在现实社会中,读者权利屡屡遭受侵害而得不到救济。造成此种原因有很多。本文从权利成本的角度出发,分析读者权利得不到及时有效救济的原因是权利的收益与权利的成本相比不相称造成的。文章最后指出只有降低读者权利成本,读者才能较好的行使读者权。

关键词：读者权权利成本权利收益信息

在线全文

学校读者我要写书评

暂无评论

海绵城市理念在市政工程中的应用

江西建材 2023年第1期 351-352页

作者：黄兴勇福建皇兴生态园林建设有限公司福建福州350000

由于应用传统方法建设的市政工程道路雨水径流系数较大,且雨水二次利用率较低,规划缺乏合理性,文中提出海绵城市理念在市政工程施工中的应用。试验证明,应用海绵城市理念规划施工的市政工程道路雨水径流系数较小,且雨水二次利用率较高,... 详细信息

由于应用传统方法建设的市政工程道路雨水径流系数较大,且雨水二次利用率较低,规划缺乏合理性,文中提出海绵城市理念在市政工程施工中的应用。试验证明,应用海绵城市理念规划施工的市政工程道路雨水径流系数较小,且雨水二次利用率较高,能够有效保证市政工程环保方面的需求,有力说明了海绵城市方案是市政建设的最大亮点。通过文中研究,希望为促进海绵城市方案的应用提供一定帮助。

关键词：海绵城市理念透水砖雨水径流系数雨水二次利用率

Nd^(3+):NaYF_4玻璃陶瓷的能量传递特性

在线全文

学校读者我要写书评

暂无评论

中国稀土学报 2017年第2期35卷 221-224页

作者：黄兴勇林林熊彦柔胡旸肖芸宜宾学院物理与电子工程学院四川宜宾644007 宜宾学院物理研究所四川宜宾644007 福建师范大学物理与能源学院福建福州350007

测量了Nd^(3+):NaYF_4玻璃陶瓷的吸收光谱,根据能量传递理论,计算了Nd^(3+)-Nd^(3+)间的能量迁移几率和能量转移几率以及能量传递的微观和宏观参数。结果显示:Nd^(3+)-Nd^(3+)间的能量迁移几率在能量传递几率中占主导作用。随着Nd^(3+)-... 详细信息

测量了Nd^(3+):NaYF_4玻璃陶瓷的吸收光谱,根据能量传递理论,计算了Nd^(3+)-Nd^(3+)间的能量迁移几率和能量转移几率以及能量传递的微观和宏观参数。结果显示:Nd^(3+)-Nd^(3+)间的能量迁移几率在能量传递几率中占主导作用。随着Nd^(3+)-Nd^(3+)间的距离不断减小,能量传递的微观参数变化不明显,而对于扩散模型和跃迁模型下的能量传递宏观参数,其值随掺杂浓度的增大而增大。

关键词：微观参数宏观参数能量传递稀土

纳米晶对Er^(3+)离子各能级动态布居的影响

在线全文

学校读者我要写书评

暂无评论

宜宾学院学报 2013年第12期13卷 46-49页

作者：黄兴勇程晓洪柳福提宜宾学院物理与电子工程学院四川宜宾644007 宜宾学院物理研究所四川宜宾644007

根据前驱玻璃和纳米晶结构玻璃陶瓷中Er3+的强度参量,分别计算了各能级间的跃迁几率,建立了描述动力学过程的速率方程,证实了纳米晶结构能有效增加4F9/2能级的粒子布居数,同时减少4I9/2能级的粒子布居数.

关键词： Er3+离子 Judd-Ofelt理论速率方程

掺钕KG(WO_4)_2和KY(WO_4)_2的荧光动力学分析

在线全文

学校读者我要写书评

暂无评论

宜宾学院学报 2017年第12期17卷 102-105页

作者：胡旸黄兴勇肖芸熊彦柔段志春宜宾学院物理与电子工程学院四川宜宾644007

根据Judd-Ofelt理论及速率方程,计算出Nd^(3+):KY(WO_4)_2和Nd^(3+):KG(WO_4)_2晶体的相关光谱参数.结果表明:在同一偏振上Nd^(3+):KY(WO_4)_2的辐射寿命小于Nd^(3+):KG(WO_4)_2,Nd^(3+):KG(WO_4)_2晶体在π偏振上的辐射寿命高于σ偏振,... 详细信息

关键词： Nd3+:KGW晶体 Nd3+:KYW晶体 Judd-Ofelt理论速率方程

Janus ZrBrI光电性质的第一性原理计算

在线全文

学校读者我要写书评

暂无评论

宜宾学院学报 2024年第6期24卷 76-82页

作者：马婷婷蒲毓臻杨文军何诗怡黄兴勇宜宾学院数理学院四川宜宾644007 宜宾学院计算物理四川省高等学校重点实验室四川宜宾644007

基于密度泛函理论,采用第一性原理的平面波赝势法系统计算ZrI_(2)和Janus ZrBrI的几何结构、电子性质和光学性质.几何结构分析发现Janus结构对键长及单层厚度都存在一定影响.基于HSE06泛函计算结果表明ZrI_2和Janus ZrBrI均为准直接带... 详细信息

基于密度泛函理论,采用第一性原理的平面波赝势法系统计算ZrI_(2)和Janus ZrBrI的几何结构、电子性质和光学性质.几何结构分析发现Janus结构对键长及单层厚度都存在一定影响.基于HSE06泛函计算结果表明ZrI_2和Janus ZrBrI均为准直接带隙半导体,禁带宽度分别为0.84、1.01 eV,其价带和导带主要由Zr的4d态电子构成.同时,Janus结构能形成内建电场,进一步抑制电子空穴对的复合.利用介电函数计算得到折射率、反射谱、吸收谱、光电导率和能量损失函数等光学参数,光学性质分析表明ZrI_(2)和Janus ZrBrI在可见光的吸收系数可达10^(-4)cm^(-1),Janus结构能够实现吸收峰的蓝移.

关键词： Janus ZrBrI 第一性原理电子结构光学性质

Activation of the wnt/β-catenin/CYP1B1 pathway alleviates oxidative stress and protects the blood-brain barrier under cerebral ischemia/reperfusion conditions

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第7期19卷 1541-1547页

作者： xingyong Chen Nannan Yao Yanguang Mao Dongyun Xiao Yiyi huang Xu Zhang Yinzhou Wang Department of Neurology Fujian Provincial HospitalShengli Clinical Medical College of Fujian Medical UniversityFuzhouFujian ProvinceChina Department of Neurology Cangzhou Central HospitalCangzhouHebei ProvinceChina Fujian Academy of Medical Science FuzhouFujian ProvinceChina Key Testing Laboratory of Fujian Province FuzhouFujian ProvinceChina

Accumulating evidence suggests that oxidative stress and the Wnt/β-catenin pathway participate in stroke-induced disruption of the blood-brain ***,the potential links between them following ischemic stroke remain largely *** present study found that cerebral ischemia leads to oxidative stress and repression of the Wnt/β-catenin ***,Wnt/β-catenin pathway activation by the pharmacological inhibito r,TWS119,relieved oxidative stress,increased the levels of cytochrome P4501B1(CYP1B1)and tight junction-associated proteins(zonula occludens-1[ZO-1],occludin and claudin-5),as well as brain microvascular density in cerebral ischemia *** r,rat brain microvascular endothelial cells that underwent oxygen glucose deprivation/reoxygenation displayed intense oxidative stress,suppression of the Wnt/β-catenin pathway,aggravated cell apoptosis,downregulated CYP1B1and tight junction protein levels,and inhibited cell prolife ration and *** ofβ-catenin or knockdown ofβ-catenin and CYP1B1 genes in rat brain mic rovascular endothelial cells at least partly ameliorated or exacerbated these effects,*** addition,small interfering RNA-mediatedβ-catenin silencing decreased CYP1B1 expression,whereas CYP1B1 knoc kdown did not change the levels of glycogen synthase kinase 3β,Wnt-3a,andβ-catenin proteins in rat brain microvascular endothelial cells after oxygen glucose deprivatio n/***,the data suggest that CYP1B1 can be regulated by Wnt/β-catenin signaling,and activation of the Wnt/β-catenin/CYP1B1 pathway contributes to alleviation of oxidative stress,increased tight junction levels,and protection of the blood-brain barrier against ischemia/hypoxia-induced injury.

关键词： blood-brain barrier CYP1B1 oxidative stress oxygen glucose deprivation/reoxygenation tight junction vascular endothelial cells Wnt/β-catenin pathway β-catenin