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Improved piezoelectric and luminescent properties in Sm-modified Bi_(0.5)Na_(0.5)TiO_(3)-BaTiO_(3) multifunctional ceramics

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Journal of Materiomics 2024年第4期10卷 803-810页

作者： Shuai Cheng Kehong zhang Chongyang Li boping zhang Jianguo Chen Kang Sun Changrong zhou Jingtai Zhao Qisheng Lin Guanghui Rao Siqi Shi School of Materials Science and Engineering Shanghai UniversityShanghai200444China Guangxi Key Laboratory of Information Materials&School of Materials Science and Engineering Guilin University of Electronic TechnologyGuilin541004GuangxiChina School of Materials Science and Engineering University of Science and Technology BeijingBeijing100083China School of Information Engineering Lanzhou University of Finance and EconomicsLanzhou730020China

The 0.93(Na_(0.5)Bi_(0.5))_(1–x)Sm_(x)TiO_(3)-0.07BaTiO_(3) multifunctional ceramics were prepared by solid-phase reaction *** phase structure,microstructure,electrical and photoluminescent properties were systematically *** increasing x,the ceramics undergoes the phase transition from rhombohedral to tetragonal with some rhombohedral distortion,along with a reduced grain size and increased relative *** the other hand,the Sm3+doping enhances the electric-field driven reversible phase transition and domain size,and reduces the domain walls,thereby contributing to improved piezoelectricity and decreased depolarization temperature(T_(d))from 91℃ to 40℃.Excellent piezoelectric properties of d_(33)=213 pC/N and kp=29.9% are achieved in the x=0.010 *** excitation(407 nm),the Sm^(3+)-doped ceramic exhibits bright reddish-orange fluorescence at 564,599,646 nm and 710 nm.A polarization-induced enhancement of photoluminescence is obtained in BNBT-_(x)Sm ceramics with an improved relative intensity of emission band at 646 *** results indicate that Sm^(3+)-doped BNBT ceramics show great potential in electro-optic integration and coupling device applications.

关键词： Piezoelectricity Curie temperature Phase transitions Thermal stability Photoluminescence

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Effect of Li content on the microstructure and properties of lead-free piezoelectric(K_(0.5)Na_(0.5))_(1-x)Li_xNbO_3 ceramics prepared by SPS

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Journal of University of Science and Technology Beijing 2008年第3期15卷 314-319页

作者： Pei Zhao boping zhang Ke Wang Limin zhang Hailong zhang School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Lead-free piezoelectric （K0.5sNa0.5）1-xLixNbO3 （x = 0at%-20at%） ceramics were synthesized by spark plasma sintering （SPS） at low temperature and the effects of LiNbO3 addition on its crystal structure and properties were also studied. When the Li content was less than 6at%, a single proveskite phase with the similar structure of （K0.5Na0.5）NbO3 was formed; and a secondary phase with K3Li2Nb5O15 structure was observed in the 6at% 〈 x 〈 20at% compositional range. Furthermore, LiNbO3 existed as the third phase when the Li content was higher than 8at%. The grain sizes increased from 200-500 nm to 5-8 μm when the K3Li2Nb5O15 and LiNbO3 like phases were formed. With increasing Li content, the relative density of the ceramics first decreased from 97% to 93% and then kept constant. The piezoelectric coefficient d33, dielectric constant, and planner electromechanical coupling factor exhibited a decreasing tendency with increasing Li content because of the decrease in density and the formation of the secondary phase such as K3Li2Nb5O15 and LiNbO3. The formation of dense microstructure with a single phase is necessary in improving the properties of the （K0.5Na0.5）1-xLixNbO3 ceramics.

关键词： lead-free piezoelectric ceramics spark plasma sintering crystal structure piezoelectric properties

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Effect of solid-solution temperature on the microstructure of Fe-Ni based high strength low thermal expansion (HSLTE) alloy

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Journal of University of Science and Technology Beijing 2007年第1期14卷 46-51页

作者： Yifan Tu Jin Xu Jianfu zhang boping zhang Dongliang Zhao Central Iron ＆ Steel Research Institute Beijing 100081 China Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China

The influence of solid-solution temperature on the dissolution of carbide precipitates, the average grain size and the microhardness of the austenite matrix in an Fe-Ni based high strength low thermal expansion （HSLTE） alloy was investigated to obtain the proper temperature range of the solid-solution process. The XRD analysis, microstructure observations, and the theoretical calculations showed that the Mo-rich M2C-type precipitates in the Fe-Ni based HSLTE alloy dissolve completely at about 1100℃. The average grain size of the studied alloys increases from 14 to 46 μm in the temperature range of 1050 to 1200℃. The microhardness of the matrix decreases gust for the sake of solid-solution treatment, but then increases later with increasing solution temperature because of the solution strengthening effect.

关键词： Fe-Ni based alloy solid-solution temperature microstructure carbide dissolution

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Microstructure and electrical properties of Ti-modified (Na_(0.5)K_(0.5))(Ti_xNb_(1-x))O_3 lead-free piezoelectric ceramics

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Rare Metals 2009年第2期28卷 142-146页

作者： zhang, Qian zhang, boping Zhao, Pei Li, Haitao zhang, Limin School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

Ti-Modified (Na0.5K0.5)(TixNb1-x)O3 (NKNT) piezoelectric ceramics were fabricated by double-layer buried powder process at 1020°C for 2 h. The microstructures,and piezoelectric and dielectric properties of the lead-free NKNT ceramics were investigated. X-ray diffraction re-sults indicated that Ti4+ had diffused into the (Na0.5K0.5)NbO3 lattices to form a solid solution with a perovskite structure. The introducing of Ti into the (Na0.5K0.5)NbO3 solid solution effectively reduced the sintering temperature and...

关键词： lead-free piezoelectric ceramics Ti-doped piezoelectric property dielectric property normal sintering oxygen vacancies

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Microstructure and microwave dielectric properties of ZnO-B_2O_3 added (Ca_(0.254)Li_(0.19)Sm_(0.14))TiO_3 ceramics

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Rare Metals 2010年第3期29卷 243-247页

作者： LU Yin LI Haitao LI Qian zhang boping Department of Mechanical Engineering Henan Polytechnic Institute Nanyang 473009 China School of Materials Science and Engineering Henan University of Science and Technology Luoyang 471003 China School of Materials Science and Engineering University of Science and Technology Beijing Beijing 100083 China

The effects of ZnO-B2O3 （ZB2） on the sintering behavior and microwave dielectric properties of （Ca0.254Li0.19Sm0.14）TiO3 ceramics were investigated. The densities of the specimens reached the maximum value by adding 3 wt.% ZB2 and then decreased. The sintering temperature of the specimens was lowered from 1300 to 1100℃ without degradation of the microwave dielectric properties. The （Ca0.254Li0.19Sm0.14）TiO3＋ 3 wt.% ZB2 sintered at 1100℃ for 3 h showed good microwave dielectric properties, εr= 108.2, Qf= 6545 GHz, and rf= 6.5 ppm/℃, respectively, indicating that ZB2 was an effective sintering aid to improve the densification and microwave dielectric properties of （Ca0.254Li0.19Sm0.14）TiO3 ceramics.

关键词： microwave dielectric properties densification ceramics sintering behavior

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Thermoelectric transport properties of Bi CuSeO with embedded La0.8Sr_(0.2)CoO_3 nanoinclusions

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Science China(Technological Sciences) 2016年第7期59卷 1036-1041页

作者： LIU YaoChun LAN JinLe zhang boping LIN YuanHua NAN CeWen School of Materials Science and Engineering University of Science and Technology Beijing State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua University State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology

The efficiency-upgrading role that La0.8Sr0.2CoO3 plays in the thermoelectric properties of Bi Cu Se O（BCSO） has been studied. LSCO was introduced into BCSO, increasing the electrical conductivity from 3.3 to 52.3 S cm^-1 at 303 K, from 35.8 to 97.3 S cm^-1 at 873 K; respectively. The Seebeck coefficient of all composites still holds around or more than 200 μV/K. Based on the enhanced electrical conductivity and high Seebeck coefficient, the power factor is enhanced by approximately 35%, with the best sample reaching a maximum value of 476.7 μ Wm^-1 K^-2 at 873 K. The lattice thermal conductivity of the nanocomposites is reduced as LSCO content increases from 15 vol% to 30 vol% due to the phonon scattering by nanoparticles and grain boundaries, resulting in a significant reduction in total thermal conductivity. In short, the enhanced thermoelectric figure of merit of 0.67 at 873 K for the sample containing 20 vol% LSCO as compared to 0.53 for the pure sample; announces the promising effect of LSCO on improving thermoelectric properties of Bi Cu Se O.

关键词： Bi Cu Se O La0.8Sr0.2CoO3 thermoelectric composite

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Preparation and thermoelectric properties of Cu1.8S/CuSbS2 composites

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Journal of Advanced Ceramics 2019年第2期8卷 209-217页

作者： Chunmei TANG Doudou LIANG Hezhang LI Kun LUO boping zhang Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and Engineering University of Science and Technology Beijing

Chalcostibite(CuSbS2)is composed of earth-abundant elements and has a proper band gap(Eg=1.05 eV)as a thermoelectric(TE)***,we report the TE properties in the CuSbS2 based composites with a mole ratio of(1–x)CuSbS2–x Cu1.8S(x=0,0.1,0.2,0.3),which were prepared by mechanical alloying(MA)combined with spark plasma sintering(SPS).X-ray diffraction(XRD)and back-scattered electron image(BSE)results indicate that a single phase of CuSbS2 is synthesized at x=0 and the samples consist of CuSbS2,Cu3SbS4,and Cu12Sb4S13 at 0.1≤x≤*** correlation between the phase structure,microstructure,and TE transport properties of the bulk samples is *** electrical conductivity increases from 0.14 to 50.66 S·cm–1 at 723 K and at0≤x≤0.03,while the Seebeck coefficient holds an appropriate value of 190.51μV·K–*** highest ZT value of 0.17 is obtained at 723 K and at x=0.3 owing to the combination of a high PF183μW·m–1·K–2 and a lowκ0.8 W·m–1·K–1.

关键词： CuSbS2 phase structure ZT thermoelectric

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Development of integrated two-stage thermoelectric generators for large temperature difference

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Science China(Technological Sciences) 2019年第9期62卷 1596-1604页

作者： PEI Jun LI LiangLiang LIU DaWei zhang boping XIAO Yu LI JingFeng The Beijing Municipal Key Laboratory of New Energy Materials and Technologies School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China State Key Laboratory of New Ceramics and Fine Processing Tsinghua UniversityBeijing 100084China Huaneng Clean Energy Research Institute Beijing 102209China School of Materials Science and Engineering Beihang UniversityBeijing 100191China

Multi-stage thermoelectric(TE) modules can withstand a large temperature difference and can be used to obtain a high conversion efficiency. In this study, two-stage PbTe/Bi2Te3 TE modules were developed with an enhanced efficiency through a comprehensive study of device structure design, module fabrication, and performance evaluation. PbTe-based AgPbmSbTem+2(abbreviated as LAST) is a typically high ZT material, while the corresponding TE module was rarely reported so far. How to utilize LAST to fabricate high efficiency TE modules therefore remains a central problem. Finite element simulation indicates that the temperature stability of the two-stage module for LAST is better than that of two-segmented module. Compared to Cu,Ni, and Ni-Fe alloys, Co-Fe alloy is an effective metallization layer for PbTe due to its low contact resistance and thin diffusion layer. By sintering a slice of Cu on TE legs, pure tinfoil can be used as a common welding method for mid-temperature TE modules. A maximum efficiency(ηmax) of 9.5% was achieved in the range of 303 to 923 K in an optimized PbTe/Bi2Te3 based two-stage module, which was almost twice that of a commercial TE module.

关键词： PbTe thermoelectric two-stage module finite element method conversion efficiency

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洋金花体外抑制角质形成细胞炎性因子分泌和血管形成

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基础医学与临床 2024年第6期44卷 816-820页

作者：仉博平司昕蕾吴芬芳北京中医药大学东直门医院北京100700 北京中医药大学深圳医院(龙岗)中心实验室广东深圳518172

目的以肿瘤坏死因子(TNF-α)诱导角质形成细胞炎症为模型,研究传统草药洋金花(Datura metel L.)在银屑病治疗中可能的作用。方法使用角质形成细胞系HaCaT,构建了TNF-α诱导的银屑病细胞模型。实验分为3组:对照组、TNF-α银屑病模型组和T... 详细信息

目的以肿瘤坏死因子(TNF-α)诱导角质形成细胞炎症为模型,研究传统草药洋金花(Datura metel L.)在银屑病治疗中可能的作用。方法使用角质形成细胞系HaCaT,构建了TNF-α诱导的银屑病细胞模型。实验分为3组:对照组、TNF-α银屑病模型组和TNF-α+洋金花干预组。以ELISA法测定IL-17和CCL20水平,利用Western blot检测核因子κB(NF-κB)亚单位p65蛋白的表达,使用体外血管生成分析试剂盒进行内皮细胞成血管实验。结果与TNF-α银屑病模型组相比,洋金花提取物极显著降低了TNF-α诱导的银屑病模型细胞培养上清液中的IL-17和CCL20的水平(P<0.001);洋金花提取物显著降低了TNF-α诱导的银屑病模型细胞的NF-κB亚单位p65的表达(P<0.01);洋金花提取物有效抑制了银屑病模型组细胞培养上清液对内皮细胞血管形成的诱导作用。结论洋金花提取物能够下调NF-κB信号通路分子,减少银屑病角质形成细胞炎性因子IL-17和CCL20的产生,抑制了血管形成。这些发现为洋金花在银屑病治疗中的应用提供了新的依据。

关键词：银屑病洋金花 CCL20 血管形成

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人纤维蛋白原在急诊创伤性凝血病中的应用及危险因素分析

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当代医学 2024年第5期30卷 11-15页

作者：章柏平查波辉郭剑万小雷联保部队第九〇八医院鹰潭医疗区急诊科江西鹰潭335000

目的探讨人纤维蛋白原(FIB)在急诊创伤性凝血病中的应用及危险因素分析。方法选取2018年1月至2019年12月联保部队第九O八医院收治的100例严重外伤所致创伤性凝血病患者作为观察组,按照随机数字表法分为A组与B组,每组50例;另选取50例急... 详细信息

目的探讨人纤维蛋白原(FIB)在急诊创伤性凝血病中的应用及危险因素分析。方法选取2018年1月至2019年12月联保部队第九O八医院收治的100例严重外伤所致创伤性凝血病患者作为观察组,按照随机数字表法分为A组与B组,每组50例;另选取50例急诊创伤性非凝血病患者作为对照组。A组给予急诊创伤性常规治疗,B组在A组基础上给予人FIB治疗,对照组治疗方法同A组。比较A组和B组治疗前后凝血功能指标[活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)、FIB、D-二聚体(D-D)],24 h新鲜冰冻血浆(FFP)输注量、24 h浓缩红细胞(CRBC)输注量、ICU住院时间及病死率。采用多因素Logistic回归分析影响创伤性凝血病的危险因素。结果治疗后,两组APTT、PT均短于治疗前,FIB水平均高于治疗前,D-D水平均低于治疗前,且B组APTT、PT均短于A组,FIB水平高于A组,D-D水平低于A组,差异有统计学意义(P<0.001)。B组24 h FFP输注量、24 h CRBC输注量均少于A组,病死率低于A组,ICU住院时间短于A组,差异有统计学意义(P<0.05)。观察组APTT、PT均长于对照组,国际标准化比值(INR)、损伤严重程度评分(ISS)、急性生理学和慢性健康状况评价(APACHE)Ⅱ评分、格拉斯哥昏迷(GCS)评分及碱缺失(BD)≥6 mol/L、合并重型颅脑损伤(STBI)、体温<35℃比例均高于对照组,24 h FFP、24 h CRBC输注量均多于对照组,血红蛋白(Hb)水平、血小板计数(PLT)均低于对照组,差异有统计学意义(P<0.05)。多因素Logistic回归分析显示,PLT低、GCS评分<6分、BD≥6 mol/L、合并STBI是创伤性凝血病发生的独立危险因素(P<0.05)。结论人FIB可改善急性创伤性凝血病凝血功能,减少血液输注量,缩短ICU住院时间及降低病死率,临床疗效显著,PLT低水平、GCS评分<6分、BD≥6 mol/L、合并STBI是创伤性凝血病发生的独立危险因素。

关键词：人纤维蛋白原急诊创伤性凝血病应用效果危险因素

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