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Photoluminescent properties of tunable green-emitting oxynitride （Baa-xSrx）Si6012N2 ：Eu2＋ phosphor and its application in white LEDs

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Journal of Rare Earths 2013年第10期31卷 944-949页

作者： Guantong CHEN Weidong ZhuANG Ronghui LIU Yuanhong LIU yunsheng hu huaqiang HE National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals Grirem Advanced Materials Co. Ltd. Beijing 100088 China

Green emitting Eu2＋-doped （Ba3_xSrx）Si6012N2 solid solutions were synthesized through solid state reaction at 1350 ℃ for 10 h under a N2/H2 atmosphere. The XRD patterns revealed that the solid solution series of （Ba3 x-ySrx）Si6Ol2N2：yEu2＋ with x value ranging from 0-0.6 were established. An efficient and intense tunable green light was observed by varying the cation Sr/Ba ratio. The emission spectra exhibited an entire shift towards long wavelength with increasing ofx value, which was caused by large crystal field splitting and Stokes shift. The x value dependence of emission intensity was discovered and explained by the enhanced probability of electron from excited 4f state to 5d ground state via nonradioactive transition. Highly thermal stability and feasible color coordinates were verified. White LEDs with excellent photochromic properties were fabricated by packing GaN based blue chips and （Ba Sr）3Si6012N2：Eu2＋ phosphors. All results indicated that the （Ba3_xSrx）SirO12N2：Eu2＋ phosphors were confirmed to be a promising candidate for pc-white LEDs in solid state lighting.

关键词： oxynitride phosphor solid solution white LEDs rare earths

Facile and green route to highly luminescent ZnS-shelled CdSe nanocrystals

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Rare Metals 2009年第2期28卷 107-111页

作者： Ye Xinyua Zhuang Weidong hu yunsheng Luo Xinyu Zhao Chunlei huang Xiaowei Gen Res Inst NonFerrous Met Natl Engn Res Ctr Rare Earth Mat Beijing 100088 Peoples R China Grirem Adv Mat Co Ltd Beijing 100088 Peoples R China Jiangxi Univ Sci & Technol Sch Mat & Chem Engn Ganzhou 341000 Peoples R China

Highly luminescent CdSe/ZnS nanocrystals were obtained by adapting non-TOP-based synthesis and a subsequent two-phase ZnS shelling procedure:the core CdSe nanocrystals were synthesized in sole solvent paraffin liquid with cadmium oxide,elemental sele-nium,and oleic acid; the deposition of the ZnS shell was conducted by using zinc stearate in toluene and sodium sulfide in deionized water. The green and low-cost route was proved to be more efficient to constrain the size of core nanocrystals while tuning the ...

关键词： crystal structure characterization solvent growth from solution nanomaterials CdSe/ZnS

Luminescence modification of Eu^(3+)-activated molybdate phosphor prepared via co-precipitation

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Journal of Rare Earths 2009年第5期27卷 758-760页

作者： ZHAO Chunlei hu yunsheng ZhuANG Weidong huANG Xiaowei HE Tao National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metalsand Grirem Advanced Materials Co.Ltd.Beijing 100088China

Eu-activated CaMoO_(4)phosphors were co-precipitated in an aqueous solution,and NH_(3)·H_(2)O,NH_(4)HCO_(3)and(NH_(2))_(2)CO as pre-cipitating aid agents were compared based on the morphology and particle size distribution of the phosphor ***3+as sensitizer ion was investigated on the luminescence of CaMoO_(4):Eu,and it could strengthen the 406 nm absorption of this *** last,the scheelite CaMoO_(4):Eu and wolframite ZnMoO_(4):Eu were selected to compare their host *** result showed that the scheelite molybdate host exhibited stronger UV absorption than wolframite one.

关键词： CaMoO_(4) ZnMoO_(4) europium samarium red phosphor rare earths

民主革命时期中国共产主义青年团的巡视制度建设

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中州学刊 2022年第7期 131-140页

作者：胡云生张彦河南工程学院河南郑州451191 四川省社会科学院历史研究所四川成都610071

民主革命时期中国共产主义青年团的巡视制度建设,是以中国共产党的直接领导为逻辑起点,既有其自身内部组织结构的生成动力,亦是中国青年运动的客观需要。其设计与运行,是由中国共产主义青年团的决议、决定、指示确立的,涉及组织结构、... 详细信息

民主革命时期中国共产主义青年团的巡视制度建设,是以中国共产党的直接领导为逻辑起点,既有其自身内部组织结构的生成动力,亦是中国青年运动的客观需要。其设计与运行,是由中国共产主义青年团的决议、决定、指示确立的,涉及组织结构、人员选拔、履行职责、制度权威等一系列工作规程和行动准则,具有革命性和选择性特征。该制度的实行,为中国共产主义青年团的政治建设、思想建设、作风建设和组织建设做出了重要的历史贡献。

关键词：民主革命时期中国共产主义青年团巡视制度

Blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) phosphors for high CRI white LEDs

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Journal of Rare Earths 2021年第6期39卷 627-633,I0001页

作者： Yipeng Zhou yunsheng hu Ronghui Liu Yuanhong Liu Weidong Zhuang Min Cao Tongyu Gao Junhang Tian Yanfeng Li Guantong Chen National Engineering Research Center for Rare Earth Materials GRINM Group Co.Ltd.Beijing100088China CRIREM Advanced Materials Co. Ltd.Beijing 100088China General Research Institute for Nonferrous Metals Beijing 100088China

A broadband blue-emitting Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+)(x=0-0.2) phospho rs were synthesized,which can be used for near-UV pumped white light-emitting diodes(w-LEDs).The crystal structures,photoluminescence pro perties,external quantum efficiency,the rmal stability and application perfo rmance of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+),by partially substituting Sr^(2+) with Ca^(2+)(x=0-0.2),were studied by various analytical *** the Ca/Sr ratio of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) gradually increases,the emission peak of Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) red-shiftes from 459 to 465 nm,corrected external quantum efficiency increases from 31.8% to 42.9%,and the thermal stability is also *** mechanism of the changes of the photoluminescence emission and excitation spectra,external quantum efficiency and thermal stability properties was also investigated in *** addition,a w-LED was fabricated by using SrLu_(2)O_(4):Ce^(3+)(blue),β-sialon:Eu^(2+)(green) and(Sr,Ca)AlSiN_(3):Eu^(2+)(red) phosphors combined with a 405 nm near-UV LED chip,and its color rendering index(CRI) reaches *** Sr_(0.8)Ca_(0.2)Lu_(2)O_(4):Ce^(3+) is applied as blue phosphor to substitute SrLu_(2)O_(4):Ce^(3+),the obtained w-LED devices have high luminous efficiency,and CRI greater than *** re sults show that the Sr_(1-x)Ca_(x)Lu_(2)O_(4):Ce^(3+) can be potential blue phosphors for n-UV pumped high CRI w-LEDs application.

关键词： n-UV pumped w-LED Blue phosphor Red shift Excellent thermal stability High color rendering index Rare earths

Carbon interstitial defects causing emission red shift in YAG:Ce phosphor:First-principles calculation

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Journal of Rare Earths 2018年第12期36卷 1239-1244页

作者： Yaling Zheng Weidong Zhuang Xianran Xing Ronghui Liu Yanfeng Li Yuanhong Liu yunsheng hu Xiaoxia Chen Lei Chen Xiaole Ma National Engineering Research Center for Rare Earth Materials General Research Institute for Nonferrous Metals and Grirem Advanced Materials Co.Ltd. Department of Physical Chemistry University of Science & Technology Beijing

Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent ***,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce3+ion in Y3Al5O12:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O2-bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce3+atom and bigger 5 d centroid *** two factors cause the emission spectrum of Y3Al5O12(C):Ce3+red shift compared with that of Y3Al5O12:Ce3+. Moreover, with our comparison experiment, we find that the Y3Al5O12(C):Ce3+ has an obvious red shift compared with that of Y3Al5O12:Ce3+system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y3Al5O12:Ce3+,and provides a new route to tune the emission spectrum in Y3Al5O12:Ce3+.

关键词： YAG:Ce Carbon interstitial defects Red shift First-principles calculation Rare earths

Magnetic resonance imaging characteristics of postoperative intracranial dissemination of recurrent gliomas

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Neural Regeneration Research 2011年第33期6卷 2610-2616页

作者： Linfeng Zheng Guixiang Zhang Jinglong Zhao Han Wang Kang＇an Li Lin Zhang Xifu Wang Pengpeng Sun yunsheng hu Department of Radiology Shanghai First People＇s Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200080 China

Ten intracranial gliomas cases, that had postoperative intracranial dissemination, underwent magnetic resonance imaging （MRI） examinations, including T1 weighted imaging, fat-suppressed T1 weighted imaging, T2 weighted imaging and fluid attenuated inversion recovery （FLAIR）. Results showed that tumor metastasis had occurred via the cerebrospinal fluid, the brain white matter fibers and the surgical access site alone. On the plain MRI scans, 1/7 cases were linearly thickened with isointensity and 5/7 cases exhibited nodular foci on T1 weighted imaging; the cerebral sulci and cisterns in 2/7 cases had become shallow and five cases had nodular foci on T2 weighted imaging. FLAIR imaging revealed that the cerebral sulci and cisterns in 2/7 cases had become shallow and that six cases had affected nodular foci. The contrast-enhanced MRI scans revealed linear thickening in seven cases, nodules in seven cases, similarities to ＂mould-like＂ signs in six cases and hydrocephalus in six cases. These findings suggested that MRI with different sequences can diagnose glioma metastasis.

关键词： brain neoplasm glioma neoplasm metastasis diagnosis magnetic resonance imaging

R-matrix for the 8-Dimensional Spin Representation of Uq(so7)

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Acta Mathematica Sinica,English Series 2024年第2期40卷 485-497页

作者： Hong Mei hu Nai Hong hu School of Mathematical Sciences Suzhou University of Science and TechnologySuzhou 215009P.R.China School of Mathematical Sciences MOE Key Laboratory of Mathematics and Engineering Applications&Shanghai Key Laboratory of PMMPEast China Normal UniversityShanghai 200241P.R.China

The purpose of the paper is to describe the solution to the quantum Yang-Baxter equation associated with the 8-dimensional spin representation Tsp of Uq(so7).The self-duality of Tsp and the symmetry of the corresponding braiding matrix are ***,the minimal polynomial of the braiding R-matrix of Tsp is presented explicitly in an ingenious method by taking advantage of nice features of the spin representation Tsp.

关键词： Braiding R-matrix spin module minimal polynomial

Mapping out the reaction network of humin formation at the initial stage of fructose dehydration in water

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Green Energy & Environment 2024年第6期9卷 1016-1026页

作者： Xing Fu Yexin hu Ping hu hui Li Shuguang Xu Liangfang Zhu Changwei hu Key Laboratory of Green Chemistry and Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengduSichuan610064China State Key Laboratory of Southwestern Chinese Medicine Resources Innovative Institute of Chinese Medicine and PharmacyChengdu University of Traditional Chinese MedicineChengduSichuan611137China

The formation of humins hampers the large-scale production of 5-hydroxymethylfurfural(HMF)in ***,a detailed reaction network of humin formation at the initial stage of fructose-to-HMF dehydration in water is delineated by combined experimental,spectroscopic,and theoretical *** bimolecular reaction pathways to build up soluble humins are *** is,the intermolecular etherification of β-furanose at room temperature initiates the C12 path,whereas the C-C cleavage of a-furanose at 130-150℃ leads to C11 path,and that of open-chain fructose at 180℃ to C11' *** successive intramolecular dehydrations and condensations of the as-formed bimolecular intermediates lead to three types of soluble *** show that the C12 path could be restrained by using HCl or AlCl_(3) catalyst,and both the C12 and C110 paths could be effectively inhibited by adding THF as a co-solvent or accelerating heating rate via microwave heating.

关键词： Carbohydrates 5-hydroxymethylfurfural Reaction network Soluble humins Tautomer