检索结果-南通市图书馆

Monodisperse micro-spherical Sr_(2-z)Mg_(1+y)Y_(z)Al_(22-x)O_(36):xMn^(4+)red phosphors

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2022年第4期40卷 526-533,I0001页

作者： Jiannan Jia Mengting He Jun Wan Yuting Zhang Hai Guo Xianping Fan xusheng qiao Shiguo Chen Department of Physics Zhejiang Normal UniversityJinhua 321004China State Key Laboratory of Silicon Materials&School of Materials Science and Engineering Zhejiang UniversityHangzhou 310027China Shenzhen Key Laboratory of Polymer Science and Technology College of Materials Science and EngineeringShenzhen UniversityShenzhen 518055China

With narrow red photoluminescence (PL) bands, tetravalent Mn^(4+) doped phosphors show promising prospect in commercial application to effectively expand color gamut of phosphor converted LED displays. Here, we report a type of Sr_(2-z)Mg_(1+y)Y_(z)Al_(22-x)O_(36):xMn^(4+) phosphors with regular cage-like micro-spherical morphologies. The micron size spherical precursors were synthesized with a propylene oxide (PO) driven fast sol–gel method. The cage -like spherical morphology is beneficial to efficiently trapping much incident light to enhance the PL of the phosphors. Being calcined at 1300 ℃, Sr_(2)MgAl_(21.978)O_(36):0.022Mn^(4+) only exhibits the internal quantum efficiency (IQE) of 24.91%. With the Mg^(2+)-Mn^(4+) codoping and Y^(3+)/Sr^(2+) substituting strategies, to fulfill charge balance and produce John-Teller distortion, IQE of Sr_(2-z)Mg_(1+y)Y_(z)Al_(22-x)O_(36):xMn^(4+) can be further improved up to 36.45%. The CIE color coordinates of Sr_(2-z)Mg_(1+y)Y_(z)Al_(22-x)O_(36):xMn^(4+) under near ultraviolet excitation can be stably fixed to (0.723, 0.227) at deep red region. It thus finds a potential application as pc-LED display with much broader color gamut than that of the NTSC standard. Therefore, Sr_(2-z)Mg_(1+y)Y_(z)Al_(22-x)O_(36):xMn^(4+) micron size spheres can be employed as promising red phosphors for high performance LED displays.

关键词： Mn^(4+) Sr_(2-z)Mg_(1+y)Y_(z)Al_(22-x)O_(36) LED phosphor Cage-like micro-sphere Luminescence Rare earths

Converting furfural residue wastes to carbon materials for high performance supercapacitor

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2022年第6期7卷 1270-1280页

作者： Xiaoying Guo xusheng Zhang Yingxiong Wang Xiaodong Tian Yan qiao State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan030001China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China CAS Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuan030001China Shanxi Engineering Research Center of Biorefinery Institute of Coal ChemistryChinese Academy of Sciences27 South Taoyuan RoadTaiyuan030001China

Sustainable development based on the value-added utilization of furfural residues(FRs)is an effective way to achieve a profitable circular economy.This comprehensive work highlights the potential of FRs as precursor to prepare porous carbons for high performance supercapacitors(SCs).To improve the electrochemical performance of FR-based carbon materials,a facile route based on methanol pretreatment coupled with pre-carbonization and followed KOH activation is proposed.More defects could be obtained after methanol treatment,which is incline to optimize textural structure.The activated methanol treated FR-based carbon materials(AFRMs)possess high specific surface area(1753.5 m^(2) g^(-1)),large pore volume(0.85 cm^(3) g^(-1)),interconnected micro/mesoporous structure,which endow the AFRMs with good electrochemical performance in half-cell(326.1 F g^(-1) at 0.1 Ag^(-1),189.4 Fg^(-1) at 50 A g^(-1) in 6 mol L^(-1) KOH).The constructed symmetric SCs based on KOH,KOH–K_(3)Fe(CN)_(6) and KOH-KI electrolyte deliver energy density up to 8.9,9.9 and 10.6 Wh kg^(-1) with a capacitance retention of over 86%after 10,000 cycles.Furthermore,the self-discharge can be restrained by the addition of K_(3)Fe(CN)_(6) and KI in KOH electrolyte.This study provides an effective approach for high-valued utilization of FR waste.

关键词： Furfural residue Methanol Porous carbon materials Electrolyte additives Supercapacitor

Eddy current loss analysis and frequency optimization design of double-sided LCC-IPT system in seawater environment

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2022年第2期65卷 407-418页

作者： SUN Pan WU xusheng CAI Jin WANG XiaoNa ZHANG XiaoChen LIANG Yan XIONG qiao RONG EnGuo School of Electrical Engineering Navy University of EngineeringWuhan 430033China

Inductive power transfer system can generate eddy current when operating in seawater medium. On the one hand, it can cause eddy current loss, and reduce operating efficiency of the system. On the other hand, it can change parameters of the system and increase difficulty of system design. To grasp the influence mechanism of seawater on the inductive power transfer system,firstly, an equivalent circuit model of double-sided inductor-capacitor-capacitor(LCC) inductive power transfer system in seawater environment was established based on loosely-coupled transformer model of eddy current. Then, based on Maxwell’s equations, the distribution function of the magnetic field and electric current density along radium direction of the coupling coils in seawater medium was obtained by analytical calculation. Besides, in combination with Biot-Savart law, expression of the eddy current loss in transfer direction was derived, and based on which expression of the equivalent of the eddy current loss on the coupling coils was got. Thus the equivalent resistance of the eddy current on the coupling coils in a seawater environment could be predicated, and the optimal operating frequency of the inductive power transfer system could be further optimized. Finally, a prototype of inductive power transfer system was established, which gave the experimental results, and verified the correctness of theoretical analysis, and the experiments showed that: in air medium, the transfer distance was 100 mm, the transfer power was 3.3 k W, and the transfer efficiency was 92.6%;while, in seawater medium, the transfer efficiency was 87%. Eddy current losses mainly caused the reduction in efficiency, and the experimental results of eddy current loss were consistent with the simulation results.

关键词： inductive power transfer seawater eddy current loss Biot-Savart law

DeepDrug:A general graph-based deep learning framework for drug-drug interactions and drug-target interactions prediction

在线全文

学校读者我要写书评

暂无评论

Quantitative Biology 2023年第3期11卷 260-274页

作者： Qijin Yin Rui Fan xusheng Cao qiao Liu Rui Jiang Wanwen Zeng Ministry of Education Key Laboratory of Bioinformatics Research Department of Bioinformatics at the Beijing National Research Center for Information Science and TechnologyCenter for Synthetic and Systems BiologyDepartment of AutomationTsinghua UniversityBeijing 100084China College of Software Nankai UniversityTianjin 300350China Department of Statistics Stanford UniversityStanfordCA 94305USA

Background:Computational approaches for accurate prediction of drug interactions,such as drug-drug interactions(DDIs)and drug-target interactions(DTIs),are highly demanded for biochemical researchers.Despite the fact that many methods have been proposed and developed to predict DDIs and DTIs respectively,their success is still limited due to a lack of systematic evaluation of the intrinsic properties embedded in the corresponding chemical structure.Methods:In this paper,we develop DeepDrug,a deep learning framework for overcoming the above limitation by using residual graph convolutional networks(Res-GCNs)and convolutional networks(CNNs)to learn the comprehensive structure-and sequence-based representations of drugs and proteins.Results:DeepDrug outperforms state-of-the-art methods in a series of systematic experiments,including binary-class DDIs,multi-class/multi-label DDIs,binary-class DTIs classification and DTIs regression tasks.Furthermore,we visualize the structural features learned by DeepDrug Res-GCN module,which displays compatible and accordant patterns in chemical properties and drug categories,providing additional evidence to support the strong predictive power of DeepDrug.Ultimately,we apply DeepDrug to perform drug repositioning on the whole DrugBank database to discover the potential drug candidates against SARS-CoV-2,where 7 out of 10 top-ranked drugs are reported to be repurposed to potentially treat coronavirus disease 2019(COVID-19).Conclusions:To sum up,we believe that DeepDrug is an efficient tool in accurate prediction of DDIs and DTIs and provides a promising insight in understanding the underlying mechanism of these biochemical relations.

关键词： drug-drug interaction drug-target interaction graph neural network deep learning

硅酸盐玻璃稳定的具有温度依赖分子荧光的银量子团簇

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

材料科学与工程学报 2022年第2期40卷 181-190,204页

作者：任锴乔旭升樊先平浙江大学材料科学与工程学院浙江杭州310027

类分子银量子团簇([Ag m]^(n+)QCs)有着亚纳米的尺寸,可以产生宽谱高效的荧光。然而[Ag m]^(n+)QCs具有很高的化学活性,因此需要配体对其进行稳定。本研究利用硅酸盐玻璃网络稳定银量子团簇,揭示了[Ag m]^(n+)QCs的分子荧光机理,研究了[... 详细信息

类分子银量子团簇([Ag m]^(n+)QCs)有着亚纳米的尺寸,可以产生宽谱高效的荧光。然而[Ag m]^(n+)QCs具有很高的化学活性,因此需要配体对其进行稳定。本研究利用硅酸盐玻璃网络稳定银量子团簇,揭示了[Ag m]^(n+)QCs的分子荧光机理,研究了[Ag m]^(n+)QCs的温度传感性能。本研究采用熔融冷却法制备了一系列SiO_(2)-ZnF_(2-x)Ag玻璃。NMR和XPS表征结果表明,三种形态的[SiO 4]四面体(Q 4、Q 3、Q 2)和[ZnO 4]四面体连接成三维玻璃网络结构。[Ag m]^(n+)QCs峰值固定的荧光可以通过分子荧光机理来描述。[Ag m]^(n+)QCs的绿白色荧光主要来自于三重态-单重态之间的跃迁(T 1→S 0)。单重态(S 1)和三重态(T 1)之间的声子耦合系间窜越确定了[Ag m]^(n+)QCs的一系列与温度有关的荧光行为,其中荧光寿命(λex=350 nm,λem=515 nm)的最大灵敏度为0.44%。因此,硅酸盐稳定的[Ag m]^(n+)QCs可以用作温度传感探针,尤其是在低温下(100~300 K)更具优势。

关键词：银量子团簇硅酸盐玻璃分子荧光温度传感环境下

含有YAG∶Ce^(3+)和CASN∶Eu^(2+)的LED照明多相荧光玻璃陶瓷

在线全文

学校读者我要写书评

暂无评论

材料科学与工程学报 2022年第6期40卷 909-914,939页

作者：何梦婷乔旭升樊先平浙江大学硅材料国家重点实验室/材料科学与工程学院浙江杭州310027

采用热压烧结法制备得到了一种掺有YAG∶Ce^(3+)黄色荧光粉和CASN∶Eu^(2+)红色荧光粉的烧结玻璃陶瓷。利用X射线衍射仪、扫描电子显微镜和荧光光谱仪对比研究了热压烧结后的烧结玻璃陶瓷和烧结前荧光粉的晶体结构和微观形貌方面的变化... 详细信息

采用热压烧结法制备得到了一种掺有YAG∶Ce^(3+)黄色荧光粉和CASN∶Eu^(2+)红色荧光粉的烧结玻璃陶瓷。利用X射线衍射仪、扫描电子显微镜和荧光光谱仪对比研究了热压烧结后的烧结玻璃陶瓷和烧结前荧光粉的晶体结构和微观形貌方面的变化,结果显示,荧光相在玻璃基质中没有发生聚集现象,且不会被玻璃基质侵蚀,能保持其发光性能。光谱研究和光电参数分析显示,在YAG∶Ce^(3+)黄色荧光粉中引入CASN∶Eu^(2+)红色荧光粉,可以有效改善其发光性能,其中显色指数最高为90,色温为4787 K,明显改善了商用LED照明器件色温高,显色指数低等问题。

关键词：发光二极管玻璃陶瓷热压烧结法荧光粉

在线全文

学校读者我要写书评

暂无评论

稀土掺杂紫外上转换材料及激光器研究进展

激光与光电子学进展 2022年第15期59卷 176-191页

作者：王淏宇乔旭升樊先平浙江大学材料科学与工程学院浙江杭州310027

稀土离子具有独特的阶梯状能级,在上转换发光领域备受瞩目。稀土掺杂紫外上转换材料是实现紫外短波长紧凑激光器的有效途径。但在稀土离子的紫外上转换过程中,会产生大量非必要的能量损耗,导致紫外高阶上转换效率极低。因此,大功率的紫... 详细信息

稀土离子具有独特的阶梯状能级,在上转换发光领域备受瞩目。稀土掺杂紫外上转换材料是实现紫外短波长紧凑激光器的有效途径。但在稀土离子的紫外上转换过程中,会产生大量非必要的能量损耗,导致紫外高阶上转换效率极低。因此,大功率的紫外上转换激光难以获得,紫外上转换激光器的实际应用受到限制。通过降低基质声子能、调控基质微观结构、改进泵浦方式、调整激光谐振腔形貌等方式,可以有效调控紫外上转换过程中的能量传递,提高紫外上转换激光的效率。本文综述了上转换发光的基本原理、紫外上转换发光材料的构成、增强紫外上转换发光的策略,以及紫外上转换激光器研究的最新进展。

关键词：激光器紫外上转换激光器激光谐振腔稀土紫外上转换材料核壳结构

电子玻璃中碱金属离子扩散行为的分子动力学研究

在线全文

学校读者我要写书评

暂无评论

燕山大学学报 2017年第4期41卷 304-310页

作者：赵亚贤刘涌乔旭升韩高荣浙江大学材料科学与工程学院浙江杭州310027 浙江大学硅材料国家重点实验室浙江杭州310027

电子玻璃是应用于电子、微电子、光电子领域的一类高技术产品,随着电子产品的轻薄化需求越来越高,超薄电子玻璃的研究成为国内外研究重点。本文利用经典分子动力学对比研究了钠钙硅酸盐玻璃和高碱高铝硅酸盐玻璃的微观结构和碱金属离子... 详细信息

电子玻璃是应用于电子、微电子、光电子领域的一类高技术产品,随着电子产品的轻薄化需求越来越高,超薄电子玻璃的研究成为国内外研究重点。本文利用经典分子动力学对比研究了钠钙硅酸盐玻璃和高碱高铝硅酸盐玻璃的微观结构和碱金属离子的扩散行为。模拟统计了两种电子玻璃中的径向分布函数,Si-O键长约为0.161 nm,Al-O键长约为0.174 nm,与文献值对比验证了模拟结果的可靠性。键长键角分析结果表明,玻璃体系中阳离子与O的作用力大小顺序为Si>Al>Mg>Ca>Na>K;网络外体使[SiO_4]四面体和[AlO_4]四面体发生变形,由于Al-O之间的作用力稍弱,变形程度更大。[SiO_4]四面体和[AlO_4]四面体的连接能够提供更宽的离子扩散通道,高碱高铝硅酸盐玻璃模拟计算700 K时Na^+的扩散系数约为4.22×10^(-11)m^2/s,K^+约为0.76×10^(-11)m^2/s。

关键词：电子玻璃经典分子动力学玻璃微观结构离子扩散

氟氧化物玻璃陶瓷不同配位环境下Cr3+的荧光温度传感特性

在线全文

学校读者我要写书评

暂无评论

硅酸盐学报 2018年第11期46卷 1543-1550页

作者：王长建 Abhishek Wadhwa 陈晓桐徐秀瑕任锴乔旭升樊先平浙江大学材料科学与工程学院

通过对基质成分为50SiO2–20Al2O3–30BaF2的玻璃进行热处理,得到了含BaF2：Cr^3＋纳米晶的透明氟氧化物微晶玻璃。玻璃陶瓷中存在两种发光中心,所对应的发光峰位中心位置分别位于红光区域724 nm处和近红外区域988 nm处。在低温环境下对... 详细信息

通过对基质成分为50SiO2–20Al2O3–30BaF2的玻璃进行热处理,得到了含BaF2：Cr^3＋纳米晶的透明氟氧化物微晶玻璃。玻璃陶瓷中存在两种发光中心,所对应的发光峰位中心位置分别位于红光区域724 nm处和近红外区域988 nm处。在低温环境下对Cr^3＋的荧光寿命与温度的关系进行了探究,724 nm处的荧光寿命的相对敏感系数温度在317 K达到最大值0.58%/K,988 nm处的荧光寿命的相对敏感系数温度在184 K达到最大值0.47%/K。

关键词：铬离子氟氧化物玻璃陶瓷低温温度传感