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Journal of Advanced Ceramics 2021年第4期10卷 809-819页

作者： tianxiang yan Kaiyuan CHEN Chengqi LI Min LIU Jie WANG Liang FANG Laijun LIU College of Mechanical and Control Engineering&College of Materials Science and Engineering Guilin University of TechnologyGuilin 541004China Institute of Fluid Engineering Equipment Jiangsu Industrial Technology Research InstituteJiangsu UniversityZhenjiang 212013China Key Laboratory for RF Circuits and Systems Ministry of Education&Key Laboratory of Large Scale Integrated DesignHangzhou Dianzi UniversityHangzhou 310018China

(1-x)K_(0.5)Na_(0.5)Nb0_(3-x)Bi(Zn_(2/3)Nb_(1/3))0_(3)((1-x)KNN-xBZN,x=0.010,0.015,0.020,0.025,and 0.030)lead-free ceramics were fabricated via a traditional solid-state *** crystal structure,microstructure,dielectric,and conductivity behavior of this system were *** with X-ray diffraction(XRD)patterns,Rietveld refinement,and dielectric spectroscopy,an orthorhombic phase was determined for x=0.010,an orthorhombic-tetragonal mixed phase was identified for x=0.015,and a rhombohedral symmetry appears in 0.020≤x≤*** 0.98KNN-0.02BZN and 0.975KNN-0.025BZN ceramics exhibit stable permittivity and low dielectric loss tangent(tan)in wide temperature ranges owing to the combination of rhombohedral-tetragonal step-like feature and the diffuse phase transition from tetragonal to *** activation energies of dielectric relaxation and conductivity behavior at high temperatures initially decrease slightly,then drop sharply,and finally decline slowly,which could be attributed to microstructure morphologies and the concentration of oxygen vacancies.

关键词： ceramic crystal structure dielectric spectroscopy oxygen vacancies

Self-supported ultrathin NiCo layered double hydroxides nanosheets electrode for efficient electrosynthesis of formate

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Journal of Energy Chemistry 2023年第10期85卷 267-275,I0008页

作者： Haoyuan Chi Jianlong Lin Siyu Kuang Minglu Li Hai Liu Qun Fan tianxiang yan Sheng Zhang Xinbin Ma Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China

Electrochemical CO_(2)reduction into energy-carrying compounds,such as formate,is of great importance for carbon neutrality,which however suffers from high electrical energy input and liquid products ***,we fabricated self-supported ultrathin NiCo layered double hydroxides(LDHs)electrodes as anode for methanol electrooxidation to achieve a high formate production rate(5.89 mmol h^(-1)cm^(-2))coupled with CO_(2)electro-reduction at the cathode.A total formate faradic efficiency of both anode for methanol oxidation and cathode for CO_(2)reduction can reach up to 188%driven by a low cell potential of only 2.06 V at 100 mA cm^(-2)in membrane-electrode assembly(MEA).Physical characterizations demonstrated that Ni^(3+)species,formed on the electrochemical oxidation of Ni-containing hydroxide,acted as catalytically active species for the oxidation of methanol to ***,DFT calculations revealed that ultrathin LDHs were beneficial for the formation of Ni^(3+)in hydroxides and introducing oxygen vacancy in NiCo-LDH could decrease the energy barrier of the rate-determining step for methanol *** work presents a promising approach for fabricating advanced electrodes towards electrocatalytic reactions.

关键词： CO_(2)reduction Methanol oxidation reaction Formate Layered double hydroxides Oxygen vacancies

Tandem electrocatalysis for CO_(2) reduction to multi-carbons

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Science China Chemistry 2024年第11期67卷 3631-3651页

作者： Xindi Li tianxiang yan Yichen Meng Zhanpeng Liang Tianying Zhang Haoyuan Chi Ziting Fan Yifan Jin Haoran Zhang Sheng Zhang Key Laboratory for Green Chemical Technology of Ministry of Education Collaborative Innovation Centre of Chemical Science and EngineeringSchool of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China Haihe Laboratory of Sustainable Chemical Transformations Tianjin 300192China Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China

The rising CO_(2) concentration in the atmosphere due to extensive use of fossil fuels has led to serious climate and environmental issues. One efficient solution is that CO_(2) capture from industrial emissions followed its conversion into value-added chemicals driven by renewable energies. CO_(2) electroreduction(CO_(2) RR) features a green and sustainable fashion towards effective CO_(2) conversion, but still suffers from low multi-carbon selectivity and yield. Considering the pivotal role of CO intermediate in C–C coupling to multi-carbon formation, tandem CO_(2) RR systems with separated CO generation and consumption components could facilitate the coupling between *CO-based intermediates to energy-intensive multi-carbons by manipulating CO diffusion and surface coverage. In this aspect, we comprehensively reviewed the design principles of tandem systems for CO_(2) electroreduction reaction. The chemistry behind the C–C coupling regarding to their distribution and diffusion was initially introduced, which was followed by achievements on tandem architectures, from catalysts, electrodes to systems. Future directions and perspectives on advanced tandem system designs for CO_(2) RR were discussed at the end. This review contributes to the understanding of structureperformance correlations in tandem catalysis and helps guide the effective collection of multi-carbons of high-yield and highselectivity.

关键词： electrocatalytic CO_(2)reduction tandem electrocatalysis design CO mass transfer model

Influence of interface point defect on the dielectric properties of Y doped CaCu_(3)Ti_(4)O_(12) ceramics

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Journal of Advanced Dielectrics 2016年第1期6卷 74-82页

作者： Jianming Deng Xiaojun Sun Saisai Liu Laijun Liu tianxiang yan Liang Fang Brahim Elouadi Key Laboratory of Nonferrous Materials and New Processing Technology Ministry of Education Guilin University of TechnologyGuilin 541004P.R.China College of Materials Science and Engineering Guangxi Universities Key Laboratory of Non-ferrous Metal Oxide Electronic Functional Materials and DevicesGuilin University of Technology Guilin 541004P.R.China Laboratory of Chemical Analysis Elaboration and Materials Engineering(LEACIM)Universite de La RochelleAvenue Michel Crepeau17042 La Rochelle Cedex 01France

CaCu_(3)Ti_(4-x)Y_(x)O_(12)(0≤x≤0.12)ceramics were fabricated with conventional solid-state reaction *** structure and microstructure of prepared ceramics were characterized by X-ray diffraction(XRD)and scanning electron microscopy(SEM),*** impedance and modulus tests both suggested the existence of two different relaxation behavior,which were attributed to bulk and grain boundary *** addition,the conductivity and dielectric permittivity showed a step-like behavior under 405 ***,frequency independence of dc conduction became dominant when above 405 *** CCTO ceramic,rare earth element Y^(3+)ions as an acceptor were used to substitute Ti sites,decreasing the concentration of oxygen vacancy around grainelectrode and grain *** reason to the reduction of dielectric behavior in low frequencies range was associated with the Y doping in CCTO ceramic.

关键词： CaCu_(3)Ti_(4)O_(12) grain boundary bulk conduction electrochemical techniques dispersion dielectric properties

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基于电气控制的齿轮范成仪设计

实验技术与管理 2016年第10期33卷 107-109页

作者：严天祥陈静黄灿华黄华东桂林理工大学机械与控制工程学院广西桂林541004

针对传统渐开线齿轮范成仪采用手动推动滑板进行实验不便于教学讲解和实验操作,设计制作了一种电气控制的齿轮范成仪,通过齿轮齿条实现机构的平稳传动,通过电气电路实现范成仪的自动化操作。实验表明所设计的范成仪不仅可以精确控制滑... 详细信息

针对传统渐开线齿轮范成仪采用手动推动滑板进行实验不便于教学讲解和实验操作,设计制作了一种电气控制的齿轮范成仪,通过齿轮齿条实现机构的平稳传动,通过电气电路实现范成仪的自动化操作。实验表明所设计的范成仪不仅可以精确控制滑板移动的距离使齿廓包络线间隔均匀,而且节省了实验过程中的调整时间,更有利于实验教学。

关键词：范成仪渐开线齿廓电气控制

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伞状浮动阀压电泵的设计与试验

中国机械工程 2024年第11期35卷 1971-1976,1985页

作者：严天祥宋检祥倪辉李先瑄陈虎城桂林理工大学广西高校先进制造与自动化技术重点实验室桂林541006 桂林理工大学机械与控制工程学院桂林541006 桂林电子科技大学机电工程学院桂林541004

针对球阀压电泵输出性能不佳和伞阀压电泵易于疲劳失效的问题,基于球阀的浮动式工作原理和伞阀的结构特征,设计了一种性能优良且不易疲劳失效的伞状浮动阀压电泵。制作了伞状浮动阀压电泵与球阀压电泵的样机,测试分析了两种泵的输出性... 详细信息

针对球阀压电泵输出性能不佳和伞阀压电泵易于疲劳失效的问题,基于球阀的浮动式工作原理和伞阀的结构特征,设计了一种性能优良且不易疲劳失效的伞状浮动阀压电泵。制作了伞状浮动阀压电泵与球阀压电泵的样机,测试分析了两种泵的输出性能。研究结果表明,当驱动电压为300 V(峰峰值)时,伞状浮动阀压电泵的最大流量和最高压力差均优于球阀压电泵。对伞状浮动阀压电泵进行了双入口结构改进,试验对比了双入口与单入口伞状浮动阀压电泵的输出性能。试验结果表明,在驱动电压300 V_(pp)下,双入口伞状浮动阀压电泵的最大流量和最大压力差分别为121.66 g/min和7.71 kPa,较单入口伞状浮动阀压电泵分别提高17.23%和32.93%。

关键词：球阀伞状浮动阀压电泵流量压力差

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半圆柱阻流体锥形腔无阀压电泵

压电与声光 2023年第6期45卷 839-844页

作者：严天祥龙志文李成其陈虎城秦建华桂林理工大学机械与控制工程学院高校先进制造与自动化技术重点实验室广西桂林541006 桂林电子科技大学机电工程学院广西桂林541004

为了提高半圆柱阻流体无阀压电泵的流量,结合锥形腔的流阻不等特性,该文设计了一种半圆柱阻流体锥形腔无阀压电泵,并建立了其流量的理论公式。数值模拟了该泵的泵腔流速分布,对比分析了其与半圆柱阻流体无阀压电泵的阻力特性。模拟结果... 详细信息

为了提高半圆柱阻流体无阀压电泵的流量,结合锥形腔的流阻不等特性,该文设计了一种半圆柱阻流体锥形腔无阀压电泵,并建立了其流量的理论公式。数值模拟了该泵的泵腔流速分布,对比分析了其与半圆柱阻流体无阀压电泵的阻力特性。模拟结果表明,半圆柱阻流体锥形腔无阀压电泵能实现流体的单向输送,且其输送能力优于半圆柱阻流体无阀压电泵。制作了两种泵的样机并进行了流量和压力差试验。试验结果表明,在驱动电压220 V下,半圆柱阻流体锥形腔无阀压电泵的最高流量和压力差分别为30.96 g/min和394 Pa,与半圆柱阻流体无阀压电泵相比,其流量和压力差均得到提高。

关键词：半圆柱锥形腔无阀压电泵流量压力差

三氮唑修饰ZIF-67材料的制备及其对碘的捕获研究

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离子交换与吸附 2022年第1期38卷 25-34页

作者：黄菊陈乐燕天祥张楠陈群何明阳张致慧常州大学石油化工学院江苏省绿色催化与技术重点实验室

采用2-甲基咪唑为主配体、1,2,4-三氮唑(3NIM)为修饰配体，与钴离子反应制备三氮唑修饰ZIF-67材料，通过配体修饰调节其表面形貌，得到了一种具有与ZIF-67相同晶体结构的金属-有机骨架材料ZIF-67 (3NIM)。红外光谱结果显示三氮唑配体进... 详细信息

采用2-甲基咪唑为主配体、1,2,4-三氮唑(3NIM)为修饰配体，与钴离子反应制备三氮唑修饰ZIF-67材料，通过配体修饰调节其表面形貌，得到了一种具有与ZIF-67相同晶体结构的金属-有机骨架材料ZIF-67 (3NIM)。红外光谱结果显示三氮唑配体进入ZIF-67的骨架中；热重分析表明，该材料具有良好的热稳定性；场发射扫描电镜结果表明，其粒径较3NIM修饰前增大，但随着修饰配体浓度的升高团簇现象变得更为严重。将ZIF-67 (3NIM)材料应用于碘单质的气相和液相吸附中，在75℃下对碘蒸气的吸附量可达到6.66g/g，较未修饰的ZIF-67 (碘吸附量5.16g/g)提高了29%；在环己烷溶液中的碘去除率也有显著提高，去除率最高可达97.5%。结果表明，氨基配体修饰的ZIF-67系列材料有望用于放射性碘的高效去除。

关键词：碘金属-有机骨架材料吸附分离氨基配体修饰

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超声波振动与热床对熔融沉积成型的影响

中国塑料 2022年第8期36卷 87-91页

作者：凌远志王海雄李亚君何金辉严天祥桂林理工大学机械与控制工程学院广西桂林541004

为了研究超声波振动与热床对熔融沉积成型技术制造出的聚对苯二甲酸乙二醇酯⁃1,4⁃环己烷二甲醇酯(PETG)试件力学性能的影响,在现有熔融沉积成型设备的基础上加入超声波振动装置,通过改变超声波功率、热床温度分别获得拉伸试件和压缩试件... 详细信息

为了研究超声波振动与热床对熔融沉积成型技术制造出的聚对苯二甲酸乙二醇酯⁃1,4⁃环己烷二甲醇酯(PETG)试件力学性能的影响,在现有熔融沉积成型设备的基础上加入超声波振动装置,通过改变超声波功率、热床温度分别获得拉伸试件和压缩试件,并对试件力学性能进行测试。结果表明,在其他成型参数相同条件下,超声波功率在0~30 W以内时,拉伸强度随着超声波功率的增加而增大,但超声波功率过大易使试件发生翘曲变形;超声波振动能提高试件的压缩强度,当其功率为12 W时,压缩强度最大;热床温度为70℃时可获得质量较好的试件,但热床温度变化对试件力学性能的影响不显著。

关键词：超声波振动热床熔融沉积成型聚对苯二甲酸乙二醇酯⁃1,4⁃环己烷二甲醇酯

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三叉四通管无阀压电泵的设计与试验

河南科技大学学报（自然科学版） 2023年第5期44卷 25-30,M0003,M0004页

作者：严天祥龙志文陈辉庆李先瑄秦建华桂林理工大学高校先进制造与自动化技术重点实验室广西桂林541006 桂林理工大学机械与控制工程学院广西桂林541006 桂林理工大学广西智能橡胶装备工程研究中心广西桂林541006

为了提高Y形管无阀压电泵的流量,基于三叉树的结构特征提出了一种三叉四通管无阀压电泵。模拟分析了三叉四通管的速度流线图,对比了该流管与Y形管的阻力特性,制作了2种流管的泵样机,进行了流量和压力差试验。研究结果表明:流体在三叉四... 详细信息

为了提高Y形管无阀压电泵的流量,基于三叉树的结构特征提出了一种三叉四通管无阀压电泵。模拟分析了三叉四通管的速度流线图,对比了该流管与Y形管的阻力特性,制作了2种流管的泵样机,进行了流量和压力差试验。研究结果表明:流体在三叉四通管中正、反向流动时均没有产生明显的旋涡,三叉四通管无阀压电泵的效率比Y形管无阀压电泵提高了22.69%。在220 V驱动电压下,三叉四通管无阀压电泵的最大流量为7.41 g/min,比Y形管无阀压电泵提升了21.47%;三叉四通管无阀压电泵的最大压力差为421 Pa,比Y形管无阀压电泵高出了79.17%。

关键词：三叉四通管 Y形管无阀压电泵流量压力差