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Enhanced piezoelectric properties in low-temperature sintered Pb(Zr,Ti)O_(3)-based ceramics via Yb_(2)O_(3)doping

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Journal of Advanced Dielectrics 2024年第4期14卷 30-37页

作者： wanfeng Zhuang weiling w.ng Yaxia Luo Hong Liu jianguo Zhu College of Materials Science and Engineering Sichuan University Chengdu 610065 P.R.China

Pb(Mg_(0.5)w_(0.5))O_(3)–Pb(Ni_(1/3)Nb_(2/3))O_(3)–Pb(Zr_(0.5)Ti_(0.5))O_(3)(PNN–PMw–PZT)piezoceramics were sintered at a low temperature of 900℃by the mixed metal oxide powder solid-state reaction ***_(3)and Li_(2)CO_(3)as sintering aids and Yb_(2)O_(3)as a dopant were added into the PNN–PMw–PZT ceramic system for low-temperature sintering and enhancement of electrical properties,*** effects of different Yb_(2)O_(3)doping amounts on the microstructure,dielectric,piezoelectric and ferroelectric properties of the samples were systematically *** piezoceramics doped with 0.1 mol%Yb_(2)O_(3)have optimal electrical properties(d_(33)=563 pC/N,k_(p)=0.66,ε_(r)=2728(1 kHz),tanδ=0.0176(1 kHz),and T_(C)=301℃).while the piezoceramics doped with 0.3 mol%Yb_(2)O_(3)have optimal energy conversion properties:the piezoelectric voltage coefficient g_(33)=26.7×10^(-3)Vm/N and the effective piezoelectric energy conversion coefficient d_(33)×g_(33)=14366×10^(-15)m^(2)/N.

关键词： Piezoelectric properties ferroelectric properties low-temperature sintering PZT energy conversion coefficient

D-band 4600 m wireless transmission with rates exceeding 100 Gbit/s based on photonics aided technologies

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Science China(Technological Sciences) 2024年第9期67卷 2968-2970页

作者： ZHAO XianMing YU JianJun YAng Xiongwei wEI Yi LI weiPing TAN Jingwen w.ng MingXu ZHAng QiuTong ZHAng Bing BIAN ChengZhen TIAN Peng HAN Yang ZHAng QingYi YU jianguo ZHAO Feng Harbin Institute of Technology Harbin 150001China Key Laboratory for Information Science of Electromagnetic waves Fudan UniversityShanghai 200433China School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China School of Automation Xi’an University of Posts and TelecommunicationsXi’an 710121China

with the rise of emerging applications such as artificial intelligence(AI),virtual reality(VR), and short videos, the number of Internet terminals has increased dramatically [1]. According to the Cisco Annual Traffic Survey Report, annual traffic is grow.ng at a compound annual growth rate of 20%[2]. To meet exploding growth in traffic demands, researchers have turned their attention to license-free high-band millimeter wave(MMw), such as w-band(75–110 GHz), D-band(110–170 GHz), and terahertz band(THz) [3,4].

关键词： millimeter exceeding artificial

Enhanced electrical properties and Vickers hardness of calcium bismuth niobate ceramics by w/Co substituted at B-site

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Journal of Advanced Dielectrics 2024年第4期14卷 92-103页

作者： Fei w.ng Jia Yang Qing Yang Ning Chen Xinji Yang Mingyue Mo Jie Xing Zhi Tan Zhongqing Tian Fancheng Meng Yuheng Guo Huixing Lin jianguo Zhu College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054P.R.China College of Materials Science and Engineering Sichuan UniversityChengdu 610064P.R.China School of Electronic Engineering Chengdu Technological UniversityChengdu 611730P.R.China Key Laboratory of Inorganic Functional Material and Device Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 201899P.R.China

Calcium bismuth niobate(CBN)ceramic,as a core element of high-temperature piezoelectric sensors,has attracted widespread attention due to its high Curie temperature within the class of Aurivillius ***,CBN usually faces two *** piezoelectric constant and low *** this work,CBN-based ceramics with donor–acceptor ions(w/Co)co-substituted at B-site were prepared by solid-state reaction method,and structure–property relationship of ceramics was studied in ***-substitution of w/Co ions effectively improved the electrical property and hardness of CBN ***_(2)Nb_(1.91)(w_(2/3)Co_(1/3)T_(0.09)O_(9))exhibits enhanced electrical and mechanical properties including high resistivity of-10^(7)Ω·cm at 500℃,piezoelectric constant of-15.3 pC/N and hardness value of-3.57 *** values are two orders of magnitude,over two times,and 1.36 times higher than those of pure CBN ceramic,*** work provides a reference for exploring other bismuth-layered structural ceramics.

关键词： Calcium bismuth niobate ceramics donor and acceptor ions B-site electrical properties Vickers hardness

江西松树岗花岗岩型铌钽矿床的成矿机制及找矿方向

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岩石学报 2024年第9期40卷 2786-2802页

作者：诸泽颖王汝成王登红李建康任建国自然资源部成矿作用与资源评价重点实验室中国地质科学院矿产资源研究所北京100037 南京大学内生金属矿床成矿机制研究国家重点实验室南京大学地球科学与工程学院南京210023 南京大学关键地球物质循环教育部前沿科学中心南京210023 江西赣锋锂业集团股份有限公司新余338004

江西松树岗花岗岩型铌钽矿床位于江西省上饶市葛源镇,不仅是华南最大花岗岩型钽矿床,同时还共伴生有铌、铷、锂、钨、锡等多金属。松树岗花岗岩型铌钽矿床近地表产出石英脉型钨锡矿,深部隐伏为花岗岩型铌钽矿床。花岗岩体具有垂向分带性... 详细信息

江西松树岗花岗岩型铌钽矿床位于江西省上饶市葛源镇,不仅是华南最大花岗岩型钽矿床,同时还共伴生有铌、铷、锂、钨、锡等多金属。松树岗花岗岩型铌钽矿床近地表产出石英脉型钨锡矿,深部隐伏为花岗岩型铌钽矿床。花岗岩体具有垂向分带性,深部为花岗岩主体黄玉钠长石花岗岩,垂向向上依次为云英岩化花岗岩、钾长石花岗岩以及似伟晶岩壳。花岗岩具有特征的“雪球结构”,斑晶为石英或钾长石。松树岗铌钽矿床岩体产出铌钽氧化物(包括铌铁矿、钽铁矿、锡锰钽矿等)、锆石、锡石以及黑钨矿。铌铁矿原位U-Pb定年结果显示成矿年龄约为130Ma。铌钽氧化物、锆石、锡石等副矿物常显示明显的核边结构,其中铌钽氧化物核部为铌铁矿,边部为钽铁矿和锡锰钽矿,记录岩体经历了明显的岩浆-热液多阶段成矿过程。松树岗花岗岩云母以铁锂云母为主,Li_(2)O含量为2.89%~4.29%。主体钠长石花岗岩中铁锂云母可分为片状铁锂云母(Znw1)和细粒铁锂云母(Znw2),其中片状铁锂云母(Znw1)同样具有环带结构,且环带主要由Rb含量变化导致。片状铁锂云母核部Rb 2O为0.9%~1.16%,边部Rb 2O含量升高,最高可达4.08%。细粒铁锂云母(Znw2)分布于基质中,含有较高的Ta含量(110×10^(-6))。云英岩中出现束状或放射状产出的铁锂云母(Znw3),具有较高的Sn含量(464×10^(-6))。片状铁锂云母核边结构记录岩浆演化过程,云英化花岗岩中的铁锂云母为热液成因。松树岗花岗岩型铌钽矿床是一个高演化稀有金属花岗岩,造岩矿物铁锂云母和副矿物铌钽氧化物记录岩体经历了岩浆到热液阶段演化的过程。地表石英脉型钨锡矿以及岩体中特征的“雪球结构”是重要的高演化稀有金属花岗岩重要的找矿标志。松树岗岩体位于著名的灵山杂岩体周围,灵山岩体的边缘仍然具有出露有类似稀有金属矿床的可能,需加大对区域稀有金属矿床的找矿勘查及理论研究力度。

关键词：铌钽矿床松树岗岩体花岗岩型成矿机制

Numerical simulations of cellular detonation diffraction in a stable gaseous mixture

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Propulsion and Power Research 2016年第3期5卷 177-183页

作者： Jian Li jianguo Ning Charles B.Kiyanda Hoi Dick ng State Key Laboratory of Explosion Science&Technology Beijing Institute of TechnologyBeijing 100081China Department of Mechanical and Industrial Engineering Concordia UniversityMontréalQCH3G 1M8Canada

In this paper,the diffraction phenomenon of gaseous cellular detonations emerging from a confined tube into a sudden open space is simulated using the reactive Euler equations with a two-step Arrhenius chemistry *** two-dimensional and axisymmetric configurations are used for modeling cylindrical and spherical expansions,*** chemical parameters are chosen for a stable gaseous explosive mixture in which the cellular detonation structure is highly *** mesh refinement(AMR)is used to resolve the detonation wave structure and its evolution during the *** numerical results show that the critical channel width and critical diameter over the detonation cell size are about 1371 and 2571,*** numerical findings are comparable with the experimental observation and confirm again that the critical channel width and critical diameter differ essentially by a factor close to 2,equal to the geometrical scaling based on front curvature *** unstable mixtures where instabilities manifested in the detonation front structure play a significant role during the transmission,the present numerical results and the observed geometrical scaling provide again evidence that the failure of detonation diffraction in stable mixtures with a regular detonation cellular pattern is dominantly caused by the global curvature due to the wave divergence resulting in the global decoupling of the reaction zone with the expanding shock front.

关键词： Detonations Diffraction Pulse detonation engine Stable mixture Adaptive mesh refinement(AMR)

超高效液相色谱-三重四级杆质谱联用法同时测定荔枝中4种细胞分裂素

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果树学报 2024年第6期41卷 1228-1238页

作者：黄雨莲赵明磊马兴帅李建国徐婧农业农村部华南地区园艺作物生物学与种质创制重点实验室·华南农业大学园艺学院广州510642 广东荔枝工程中心广州510642

【目的】应用超高效液相色谱-三重四级杆质谱联用仪(UPLC-MS/MS),建立一种同时测定荔枝反式玉米素核苷(tZR)、异戊烯基腺嘌呤核苷(IPR)、二氢玉米素(DHZ)、异戊烯基腺嘌呤(IP)4种细胞分裂素含量的方法。【方法】0.25 g荔枝样品用乙腈-水... 详细信息

【目的】应用超高效液相色谱-三重四级杆质谱联用仪(UPLC-MS/MS),建立一种同时测定荔枝反式玉米素核苷(tZR)、异戊烯基腺嘌呤核苷(IPR)、二氢玉米素(DHZ)、异戊烯基腺嘌呤(IP)4种细胞分裂素含量的方法。【方法】0.25 g荔枝样品用乙腈-水(80∶20,体积比)溶液浸提8 h,经Bond Elut Plexa PCX固相萃取柱纯化,2.5%氨水甲醇洗脱后过0.22μm有机滤膜检测。选取XSelect HSS T3色谱柱,以甲醇和5 mmol·L^(-1)甲酸铵水溶液为流动相进行7 min梯度洗脱,采用电喷雾正离子(ESI+)模式电离,选择反应监测(MRM)模式对细胞分裂素进行定量。【结果】4种细胞分裂素的检出限和定量限分别低于18.12和60.39 pg·g^(-1),在0.05~50 ng·mL^(-1)质量浓度范围内呈良好的线性关系,线性相关系数(r2)大于0.999。在高、中、低浓度三种加标水平下,4种细胞分裂素的平均回收率为80.0%~108.2%,标准偏差为0.8%~15.5%。采用建立的方法可以同时检测出荔枝果皮、果肉、种子、幼果、叶片和果柄离区中4种细胞分裂素含量。【结论】该方法简便、快速、灵敏、准确,适用于荔枝不同组织中细胞分裂素含量的测定。

关键词：荔枝液质联用细胞分裂素定量测定

The impact of patent citation information flow regarding economic innovation on common stock returns:Volume *** citations

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International Journal of Innovation Studies 2018年第4期2卷 137-152页

作者： Chamil w.Senarathne jianguo wei School of Economics Wuhan University of TechnologyHubei430070China

This study examines whether the number of forward patent citations(along with alternative patent data)dwhen used as a proxy for the mixing variabledcould infer the aggregate amount of economic-innovation information arriving at the New York Stock Exchange(NYSE)in the United *** results show that the number of forward patent citations,when used as a mixing variable,fails to eliminate total volatility persistence in the conditional variance equation of the exponential generalized autoregressive conditional heteroscedastic(EGARCH)***,the trading volume successfully eliminates total volatility persistence,thus confirming the validity of the framework *** the volatility is modeled with an expectation of mean return,the persistence of conditional variance is deterministically increased,and the sum of the volatility coefficients exceeds *** inclusion of trading volume with a time trend in the variance equation rectifies the deterministic increase in the conditional *** findings suggest that the form of heteroscedasticity(i.e.,as per the autoregressive conditional heteroscedastic model,ARCH model)in NYSE portfolio returns is based on the type of shocks to volatility(e.g.,deterministic ***),which manifests as news arrivals(i.e.,new information arrivals proxied by trading volume)at the stock *** volume therefore reflects the time dependence in the innovations to the ARCH error generation *** response of volatility to volume persists over time when the volatility estimates are derived from the EGARCH model with an expectation for the mean of *** patent citations,patent applications,and patents issued have been found to interact somewhat with trading volume,suggesting that each of these variables could play the role of an absorptive capacity variable as the new information flow associated with economic innovation(i.e.,flow of firms’stock of new knowledge)could be picked up by the trading volume.

关键词： Economic innovation Patent citations Market efficiency Information flow EGARCH Trading volume

光热驱动PS-PS@PDA偏心纳米马达的制备及运动性能研究

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化学与生物工程 2024年第10期41卷 39-43页

作者：翟祥翔郭杰官建国罗明武汉理工大学材料复合新技术国家重点实验室湖北武汉430070 武汉理工大学材料科学与工程国际化示范学院湖北武汉430070

以聚苯乙烯(PS)纳米颗粒为模板,通过模板法制备了一种光热驱动聚苯乙烯-聚苯乙烯@聚多巴胺(PS-PS@PDA)偏心纳米马达,利用扫描电子显微镜、透射电子显微镜对其形貌结构进行了表征,并评价了其光热性能和运动性能。结果表明,PS-PS@PDA偏心... 详细信息

以聚苯乙烯(PS)纳米颗粒为模板,通过模板法制备了一种光热驱动聚苯乙烯-聚苯乙烯@聚多巴胺(PS-PS@PDA)偏心纳米马达,利用扫描电子显微镜、透射电子显微镜对其形貌结构进行了表征,并评价了其光热性能和运动性能。结果表明,PS-PS@PDA偏心纳米马达由1个挤出的PS小球和1个核壳结构PS@PDA大球组成,直径分别为(134.7±12.4)nm和(229.3±6.5)nm;在近红外激光照射下,纳米马达表现出良好的光热转换性能和光热稳定性;随着激光功率密度的增加,纳米马达的扩散系数逐渐增大,当功率密度为2.0 w·cm^(-2)时,扩散系数达到15.57μm^(2)·s^(-1),比布朗运动的扩散系数提高了约32倍;此外,纳米马达在不同的生物介质中依然能够维持高效驱动。

关键词：纳米马达光热偏心结构聚多巴胺模板法

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Dynamic mechanical characterization and optimization of particle-reinforced w-Ni-Fe composites

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Science China(Physics,Mechanics & Astronomy) 2011年第9期54卷 1651-1658页

作者： SOng weiDong NIng jianguo State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

A visco-plastic rate-dependent homogenization theory for particle-reinforced composites was derived and the equivalent elastic constants and the equivalent visco-plastic parameters of these composites were obtained. A framework of homogenization the- ory for particle-reinforced w-Ni-Fe composites, a kind of tungsten alloy, was established. Based on the homogenization theory and a fixed-point iteration method, a unit cell model with typical microstructnres of the composite was established by using dynamic analysis program. The effects of tungsten content, tungsten particle shape and particle size and interface strength on the mechanical properties and the crack propagation of the w-Ni-Fe composite are analyzed under quasi-static and dynamic loadings. The stress-strain curves of the composite are given and the relation between the macro-mechanical characteristics and the microstructure parameters is explored, which provides an important theoretical basis for the optimization of the w-Ni-Fe composites.

关键词： w Ni Fe composite – dynamic mechanical property – microstructure – homogenization theory – optimization