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To tune europium valence by controlling the composition in diphase silicate phosphors

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Journal of Rare Earths 2018年第10期36卷 1015-1023页

作者： Yiting Lin Jukui Zhou zhongxian qiu Wenli Zhou Jilin Zhang Chengzhi Li Liping Yu Shixun Lian Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education) Key Laboratory of Sustainable Resources Processing and Advanced Materials of Hunan ProvinceCollege of Chemistry and Chemical EngineeringHunan Normal University

Commercial phosphors always require fewer impurities and higher crystallinity, but sometimes it is difficult or strict to synthesize a pure phase compound. Indeed, if the practical application is not influenced, it is acceptable to synthesize a kind of phosphors with diphase matrix that have similar structure and photoluminescence properties. In present work, we designed and synthesized a series of（1-x）BaMSiO4·xBa2 MSi2 O7：Eu（M = Zn2＋, Mg2＋） diphase phosphors which contained two phases BaMSiO4（hexagonal, P63） and Ba2 MSi2 O7（monoclinic, C2/c） by a high temperature solid-state reaction in air condition. The structures and luminescence properties related to the phase transform from BaMSiO4 to Ba2 MSi2 O7 were analyzed carefully. The results show that the self-reduction ability of Eu3＋ is not the best in above four compounds, respectively. But it reaches the maximum and gets the green emission under the UV lamp when the matrix is in a proper ratio of two phases, which suggests that the heterostructure between the two crystals（BaMSiO4 and Ba2 MSi2 O7） improves the self-reduction process of the *** possible mechanism of the tunable europium valence and the luminescent properties in（1-x）BaMSiO4·xBa2 MSi2 O7：Eu phosphors were discussed in detail.

关键词： Diphase phosphors Silicate Heterostructure Eu Self-reduction Rare earths

Fine controllable blue emission and its mechanism in Ce^(3+)-doped orthosilicate solid solution phosphors for different plant growths

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Journal of Rare Earths 2018年第11期36卷 1150-1156页

作者： Yaru Yang Yiting Lin Yue Han zhongxian qiu Wenli Zhou Jilin Zhang Chengzhi Li Liping Yu Shixun Lian Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research (Ministry of Education) Key Laboratory of Sustainable Resources Processing and Advanced Materials of Hunan ProvinceCollege of Chemistry and Chemical EngineeringHunan Normal University

The designed Ce^3＋-doped alkaline-earth silicate phosphors CamSr2 m-nBanSiO4：Ce^3＋,Li^＋（CSBS：Ce^3＋） were synthesized by a high temperature solid-state reaction. The crystal field splitting and the centroid shift from the flee ion energy of 5d configuration were approximated from the spectrum for Ca2SiO4, Sr2SiO4 and Ba2SiO4 phosphors. The single-phase purity was checked by means of X-ray diffraction. Here, when the doped concentration of Ca2. is less than 80% （m 〈 1.6）, we report the structural phase transformation from monoclinic system [3-Ca2Si04 to orthorhombic system α′-Ca2SiO4. The phosphors excited by near-ultraviolet （NUV） light at wavelengths ranging from 200 to 400 nm demonstrate a broad asymmetric blue emission band. The emission peak wavelength redshifts firstly from 417 nm of Ca2SiO4 to 438 nm of Sro.3Cal.6SiO4, and then blueshifts to 411 nm of Sr2SiO4, and the end of 401 nm of Ba2SiOa. These results indicate that the tunable blue-emission of the phosphors can he realized through changing the solid solution components, which has a potential use as a blue component for fabricated precision modulation LEDs light sources and auxiliaries of SSC plastics films for different plant growths. We discuss in detail the possible mechanism and energy diagram of the tunable blue luminescence in CamSr2-M-nBaNSiO4：Ce^3＋.Li^＋ phosphors.

关键词： Ce^3+ Controllable blue emission Alkaline-earth silicate Solid solution Plant growth Rare earths

孤立格位中的Cr^(3+)近红外发射波长的设计与调控:以AMP_(2)O_(7):Cr^(3+)为例

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发光学报 2023年第2期44卷 246-258页

作者：吴家宇张珍珍李松廉世勋余丽萍邱忠贤湖南师范大学化学化工学院光能转换材料湖南省高校重点实验室湖南长沙410081

近红外光谱调控对于开发新型近红外荧光粉至关重要。3d^(3)电子构型的Cr^(3+)具有波长可调谐的宽带近红外发光性质,是一种理想的近红外激活剂离子。由于d轨道对晶体场敏感,Cr^(3+)离子发射波长强烈依赖于其配位晶体结构,明确配位结构与... 详细信息

近红外光谱调控对于开发新型近红外荧光粉至关重要。3d^(3)电子构型的Cr^(3+)具有波长可调谐的宽带近红外发光性质,是一种理想的近红外激活剂离子。由于d轨道对晶体场敏感,Cr^(3+)离子发射波长强烈依赖于其配位晶体结构,明确配位结构与发光性质之间的构效关系是指导近红外荧光粉理性设计的理论基础。而实际上晶体结构复杂,影响局部配位结构性质的因素很多,难以形成明确的构效关系。AMP_(2)O_(7)(A=Li,K;M=Ga,Sc,In)系列焦磷酸盐晶体中具有孤立的[MO_(6)]八面体结构特征,可为Cr^(3+)提供孤立的配位环境,孤立格位大大减少了晶体结构的复杂性,为构效关系的建立提供了合理性保障。本文以AMP_(2)O_(7):Cr^(3+)系列荧光粉为研究对象,Cr^(3+)取代在孤立的[MO6]八面体中心格位,具有波长可调谐的近红外发光性质,其发射波长随M^(3+)和A+组分变化而发生迁移,以Cr^(3+)发射波长对孤立配位结构特征的依赖关系初步构建[MO_(6)]—Cr^(3+)近红外发射波长的构效关系,以期能为Cr^(3+)近红外发射材料理性设计提供一些依据和思路。

关键词：近红外荧光粉 Cr^(3+) 构效关系

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Optical Properties and Potential Applications for Solar Cells of ZnS:Mn2+,Tm3+ Phosphors

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Optical Properties and Potential Applications for Solar Cell...

超声引导下短轴法与长轴法在新生儿颈内静脉置管中的比较

第七届全国稀土发光材料学术研讨会

作者： zhongxian qiu,Chunying Rong,Liping Yu and Shixun Lian~* (Key Laboratory of Chemical Biology & Traditional Chinese Medicine Research(Ministiy of Education) Key Laboratoiy of Sustainable Resources Processing and Advanced Materials of Hunan Province,Hunan Normal University,Changsha,Hunan 410081,China)

The color-tunable phosphors Mn -activated ZnS emitting from yellow to red have drawn significant attention and are expected to apply for electroluminescent(EL) devices as novel electrical-to-light converters in recent *** no report is about the promising application for solar cells as a spectral converter yet. Powder samples of ZnS:Mn,Tm were prepared by a solid-state *** raw materials were ZnS,

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汕头大学医学院学报 2022年第2期35卷 92-95页

作者：陈哲翟玉霞王嘉嘉邱仲贤苏鸿辉汕头大学医学院第二附属医院超声科广东汕头515041 汕头大学医学院第二附属医院超声介入科广东汕头515041

目的:探讨超声引导下短轴法与长轴法在新生儿颈内静脉置管中的应用效果。方法:回顾性分析2018年1月—2021年12月在汕头大学医学院第二附属医院新生儿科住院并行超声引导下颈内静脉穿刺置管术的69例患儿的临床资料。按照穿刺方式分为短轴... 详细信息

目的:探讨超声引导下短轴法与长轴法在新生儿颈内静脉置管中的应用效果。方法:回顾性分析2018年1月—2021年12月在汕头大学医学院第二附属医院新生儿科住院并行超声引导下颈内静脉穿刺置管术的69例患儿的临床资料。按照穿刺方式分为短轴组(34例)和长轴组(35例)。比较两组穿刺置管的术前准备时间、首次穿刺成功时间、穿刺血管次数、穿刺总耗时以及并发症发生率。结果:短轴组与长轴组颈内静脉置管术前准备时间分别为1 (1,1)、6 (5,8)min,首次穿刺成功时间分别为3 (2,4)、5 (3,7) min,穿刺总耗时分别为17.50 (13.75,19.95)、21.00 (15.00,24.00) min,短轴组颈内静脉置管的术前准备时间、首次穿刺成功时间和穿刺总耗时均短于长轴组,差异具有统计学意义(P值均0.05)。结论:超声引导下短轴法比长轴法在新生儿颈内静脉置管中操作更快速、便捷。

关键词：超声短轴法长轴法颈内静脉置管新生儿

Spatial distribution and inventory of natural gas hydrate in the Qiongdongnan Basin,northern South China Sea

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Journal of Oceanology and Limnology 2023年第2期41卷 729-739页

作者： zhongxian ZHAO Ning qiu Zhen SUN Wen YAN Genyuan LONG Pengchun LI Haiteng ZHUO Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 511458China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Hainan Key Laboratory of Marine Geological Resources and Environment Haikou 570206China Marine Geological Institute of Hainan Province Haikou 570206China School of Marine Sciences Sun Yat-sen UniversityZhuhai 519082China

Natural gas hydrate is a potential clean energy source and is related to submarine geohazard,climate change,and global carbon *** investigations have revealed the occurrence of hydrate in the Qiongdongnan Basin,northern South China ***,the spatial distribution,controlling factors,and favorable areas are not well *** we use the available high-resolution seismic lines,well logging,and heat flow data to explore the issues by calculating the thickness of gas hydrate stability zone(GHSZ)and estimating the *** show that the GHSZ thickness ranges between mostly~200 and 400 m at water depths>500 *** gas hydrate inventory is~6.5×109-t carbon over an area of~6×104 *** areas including the lower uplift to the south of the Lingshui sub-basin,the Songnan and Baodao sub-basins,and the Changchang sub-basin have a thick GHSZ of~250-310 m,250-330 m,and 350-400 m,respectively,where water depths are~1000-1600 m,1000-2000 m,and2400-3000 m,*** these deep waters,bottom water temperatures vary slightly from~4 to 2℃.However,heat flow increases significantly with water depth and reaches the highest value of~80-100 mW/m2 in the deepest water area of Changchang *** heat flow tends to reduce GHSZ thickness,but the thickest GHSZ still occurs in the Changchang sub-basin,highlighting the role of water depth in controlling *** lower uplift to the south of the Lingshui sub-basin has high deposition rate(~270-830 m/Ma in 1.8-0 Ma);the thick Cenozoic sediment,rich biogenic and thermogenic gas supplies,and excellent transport systems(faults,diapirs,and gas chimneys)enables it a promising area of hydrate accumulation,from which hydrate-related bottom simulating reflectors,gas chimneys,and active cold seeps were widely revealed.

关键词： gas hydrate stability zone gas hydrate inventory Qiongdongnan Basin South China Sea

全无机钙钛矿量子点的疏水改性及LED应用——推荐一个本科生综合化学实验

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大学化学 2023年第8期38卷 192-199页

作者：周文理张兵宋文丽张吉林邱忠贤韩跃李承志余丽萍湖南师范大学化学化工学院长沙410081

介绍一个综合化学实验——全无机钙钛矿量子点的疏水改性及LED应用。我们以三甲基氯硅烷和莫来石纤维增强SiO_(2)气凝胶的疏水性和韧性,获得疏水SiO_(2)气凝胶,随后以该疏水SiO_(2)气凝胶吸附全无机钙钛矿量子点形成CsPbX_(3)@SiO_(2)... 详细信息

介绍一个综合化学实验——全无机钙钛矿量子点的疏水改性及LED应用。我们以三甲基氯硅烷和莫来石纤维增强SiO_(2)气凝胶的疏水性和韧性,获得疏水SiO_(2)气凝胶,随后以该疏水SiO_(2)气凝胶吸附全无机钙钛矿量子点形成CsPbX_(3)@SiO_(2)气凝胶复合材料。通过接触角、红外光谱、X射线衍射等表征手段证实SiO_(2)气凝胶的成功改性,并制作了LED器件。本实验涉及材料的合成、表征和应用,可作为化学和应用化学专业学生的综合化学实验,有助于提高学生的科学素养,激发对科学研究的兴趣。

关键词：钙钛矿量子点疏水SiO_(2)气凝胶综合化学实验教学设计

Numerical simulation of incompressible Couette flow using lattice Boltzmann method

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Numerical simulation of incompressible Couette flow using la...

随机多孔介质流动的格子Boltzmann法模拟

中国计算力学大会2014暨第三届钱令希计算力学奖颁奖大会

作者： zhongxian LUO Yanjun qiu Huaqian YU School of Civil Engineering Southwest Jiaotong University

The Lattice Boltzmann Method(LBM)has been successfully used in various engineering applications in modeling the fluid *** this paper,LBM is used to simulate the two dimensional incompressible Couette *** numerical solution to the problem of incompressible Couette flow is compared with the well known analytical *** is shown that the LBM has a remarkable ability to simulate fluids flow in terms of computational efficiency and stability.

关键词： lattice Boltzmann method incompressible Couette flow Navier Stokes equations

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西南交通大学学报 2014年第1期49卷 93-96,118页

作者：罗忠贤邱延峻禹华谦西南交通大学土木工程学院四川成都610031 西南交通大学高速铁路线路工程教育部重点实验室四川成都610031 西南交通大学道路工程四川省重点实验室四川成都610031

为了探索多孔介质渗透性与孔隙率之间的关系,应用格子Boltzmann方法(LBM)以及无滑移流固边界条件,从孔隙尺度模拟了二维随机多孔介质中的流体流动.通过研究流量和压力梯度的关系,验证了格子Boltzmann方法模拟的Darcy定律.研究结果表明:... 详细信息

为了探索多孔介质渗透性与孔隙率之间的关系,应用格子Boltzmann方法(LBM)以及无滑移流固边界条件,从孔隙尺度模拟了二维随机多孔介质中的流体流动.通过研究流量和压力梯度的关系,验证了格子Boltzmann方法模拟的Darcy定律.研究结果表明:在孔隙率较低(约小于0.3)的情况下,渗透性与孔隙率近似成指数关系变化,与前人的结果吻合.

关键词：随机多孔介质格子Boltzmann方法孔隙尺度孔隙率渗透性