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Wide-Temperature-Range Dielectric Permittivity Measurement under High Pressure

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Chinese Physics Letters 2017年第4期34卷 13-17页

作者： Zhen Yuan Jin-Long Zhu Shao-Min Feng chang-chun wang Li-Juan wang Qing-Qing Liu chang-Qing Jin Department of Materials Science and Engineering Linyi University Linyi 276005 Center for High Pressure Science and Technology Advanced Research Beijing 100094 National Lab for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190

Two measurement systems are developed for in-situ dielectric property measurement under high pressure in a wide-temperature range from 77K to 1273 K. The high-temperature system ranging from room temperature up to 1273K is equipped with a hexahedron anvils press, while the low-temperature system ranging from liquid nitrogen temperature to normal condition is equipped using the piston cylinder setup with a specially designed sample chamber. Using these configurations, the dielectric property measurement of ferroelectrie BaTiO3 and multiferroie Tm0.5Gd0.5MnO3 compounds are demonstrated, which proves the validity of the systems through the tuning of the polarization and phase transition boundary by high pressure. These two systems will be equally applicable to a wide variety of electronic and transport property measurements of insulators, semiconductors, as well as battery materials.

关键词： der Wide-Temperature-Range Dielectric Permittivity Measurement under High Pressure BTO

Aza-Michael addition reactions between nitroolefins and benzotriazole catalyzed by MCM-41 immobilized heteropoly acids in water

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Chinese Chemical Letters 2013年第1期24卷 28-30页

作者： Shao-Lei Xie Yong-Hai Hui Xiang-Ju Long chang-chun wang Zheng-Feng Xie Key Laboratory of Oil & Gas Fine Chemicals Ministry of Education & Xinjiang Uyghur Autonomous RegionCollege of Chemistry and Chemical EngineeringXinjiang University

MCM-41 supported heteropoly acids （HPAs） catalysts were synthesized, characterized and their catalytic activity was evaluated in an aza-Michael addition reaction between nitroolefins and benzotriazole in water at room temperature. 50 wt% PW/MCM-41 showed the highest activity （up to 96% yield）. The catalyst was used in six consecutive experiments without obvious loss of activity, confirming the success of the anchoring process and the catalyst stability.

关键词： Aza-Michael additionMCM-41Heteropoly acidsHeterogenous catalysts

Performance variability of Ba0.5Sr0.5Co0.8Fe0.2O3-δ cathode on proton-conducting electrolyte SOFCs with Ag and Au current collectors

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Rare Metals 2018年第8期37卷 633-641页

作者： Ting-Ting Wan An-Kang Zhu Hai-Bo Li chun-chang wang You-Min Guo Zong-Ping Shao Oumarou Savadogo School of Physics and Materials Science Anhui UniversityHefei 230601China State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemistry and Chemical EngineeringNanjing University of TechnologyNanjing 210009China Department of Chemical Engineering Curtin UniversityPerth W A 6845.Australia Laboratory of New Materials for Electrochemistry and Energy Polytechnique MontrealC.P.6079Succursale Centre-VilleMontr6alQC H3C 3A7Canada

Ba0.5Sr0.5Co0.8Fe0.2O3-δ （BSCF） is one of the most active cathode materials and shows significant hydration effect suggesting possible proton conductivity. In this study, the performance of BSCF cathode on a protonconducting BaZr0.1Ce0.7Y0.2O3-δ（BZCY） electrolyte with silver and gold current collectors was determined. The electrochemical characteristics of the symmetrical and anode-supported cell with diluted silver electrode, silver current collector or gold current collector on BSCF electrode were compared. The significant result is that, although the diluted silver electrode itself shows poor operation stability, the silver current collector has strong electrocatalytic contribution to the BSCF cathode performance on the proton-conducting electrolyte, leading to higher cell performance than that with the gold current collector.

关键词： Solid oxide fuel cell Proton conductor Agcurrent collector Operation stability

Microstructure Evolution and Nanomechanical Behavior of Micro-Area in Molten Pool of Selective Laser Melting(CoCrNi)_(82)Al_(9)Ti_(9)High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1019-1033页

作者： Hong-Wei Zhang Li-Wei Lan Zhe-Yu Yang chang-chun Li Wen-Xian wang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyTaiyuan030024China Shanxi-Zhejiang University New Materials and Chemical Research Institute Taiyuan030032China

In this work,the phase evolution mechanism and nanomechanical properties of(CoCrNi))(82)Al_(9)Ti_(9)high-entropy alloy(HEA)prepared by selective laser melting(SLM)in the molten pool were *** HEA contains multiple primary elements and undergoes high-temperature gradient and rapid cooling during *** leads to significant inhomogeneity of nano-scale microstructure characteristics and instability of *** optimizing process parameters,the microstructure evolution at the optimal parameter volume energy density of 440 J/mm^(3)was studied.A phase transition from BCC to FCC occurred in the melt *** the micro-area of the melt pool results in a temperature rise and the combustion-induced loss of Al ***,the Ni element content increases significantly outside the melt *** process enhances the phase stability of FCC and facilitates phase ***,rapid cooling leads to the formation of distinctive ultrafine equiaxial crystals inside the melt pool,accompanied by the generation of intracrystalline needle-like nano-scale *** the melt pool,the accumulation of energy results in the formation of coarse ***,the nano-hardness inside the molten pool is remarkably high at 11.79 GPa,while the outside the molten pool is reduced to 9.58 *** the fracture toughness outside the melt pool also *** with inside the melt pool,the residual stress outside the melt pool changed from compressive to tensile stress and decreased from 603.28 to 322.84 MPa.

关键词： High-entropy alloys Selective laser melting Microstructure evolution Nanoindentation

Efficiency for Gene Silencing Induction in Nicotiana Species by a Viral Satellite DNA Vector

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Journal of Integrative Plant Biology 2007年第12期49卷 1726-1733页

作者： You-Ping Xu Lu-Ping Zheng Qiu-Fang Xu chang-chun wang Xue-Ping Zhou Zu-Jian Wu Xin-Zhong Cai Institute of Biotechnology Zhejiang University Hangzhou 310029 China Centre of Analysis and Measurement Zhejiang University Hangzhou 310029 China Institute of Plant Virology Fujian Agriculture and Forestry University Fuzhou 350002 China

Virus-induced gene silencing （VIGS） is a useful technique for rapid plant gene function analysis. We recently reported a new VIGS vector modified from Tomato yellow leaf curl China virus （TYLCCNV） DNAβ （DNAm β）. In this study we compared in detail DNAmβ-induced gene silencing in four Nicotiana species including N. benthamiana, N. glutinosa, N. tabacum and N. paniculata. We found that DNAmβ-induced gene silencing in the four species was distinct in developing dynamics, tissue specificity, efficiency, and constancy in the plant life span. It was most efficient in N. benthamiana, where development of VIGS was most rapid, without tissue specificity and nearly 100% efficient. DNAmβ-induced gene silencing in N. glutinosa was also efficient despite being slightly less than in N. benthamiana. It initially occurred in veins, later was scattered to mesophyll, finally led to complete silencing in whole leaves. In both species, VIGS constantly expressed until the plants died. However, DNAmβ-mediated VIGS in the other two Nicotiana species, N. tabacum and N. paniculata, was significantly less efficient. It was strictly limited within the veins of the silenced leaves, and constantly occurred only over 3-4 weeks. The upper leaves that emerged later stopped showing the silencing phenotype. DNAmβ-induced gene silencing in N. benthamiana and N. glutinosa was not significantly influenced by the growth stage when the plants were agro-inoculated, and was not sensitive to high growth temperature up to 32℃. Our results indicate that this system has great potential as a versatile VIGS system for routine functional analysis of genes in some Nicotiana species.

关键词： DNAβ Nicotiana tobacco rattle virus tomato yellow leaf curl China virus virus-induced gene silencing.

Customer Segmentation of Credit Card Default by Self Organizing Map

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American Journal of Computational Mathematics 2018年第3期8卷 197-202页

作者： Hui Wu chang-chun wang Department of Mathematics Clark Atlanta University Atlanta GA USA International Monetary Fund Washington DC USA

In this paper we applied the technique of Self Organizing Map (SOM) to segment individuals based on their credit information. SOM is an unsupervised machine learning method that reduces data complexity and dimensionality while keeping sits original topology, which is superior to other dimension reduction methods especially when features in data have unclear nonlinear relations. Through this method we provide more clear and intuitive segmentation that other traditional methods cannot achieve.

关键词： Self Organizing Map Clustering Machine Learning Credit Default

A homopolymolybdate-supported plate-like 2D cobalt network constructed from a new pyrazole-amide-pyridyl ligand: highly electrochemical activity in both capacitive performance and the detection of Cr(Ⅵ)

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Tungsten 2024年第2期6卷 422-427页

作者： Xiu-Li wang Yong-Zhen Chen Zhi-Han chang Yu-chun Lin Jing-Yi Ma College of Chemistry and Materials Engineering Bohai UniversityJinzhou 121013China Professional Technology Innovation Center of Liaoning Province for Conversion Materials of Solar Cell Jinzhou 121013China

By employing a new semi-rigid pyrazole-amide-derived bis(pyridyl)ligand[N,N'-bis(4-picolylamine)-1-hydropyrazole(4-dpap)],a new homopolymolybdate-based two-dimensional(2D)plate-like complex[Co(4-dpap)(H_(2)O)(β-Mo_(8)O_(2)6)1/2](1)has been prepared under solvothermal condition and structurally ***β-Mo_(8)anions are fi xed between the 2D metal–organic networks[Co(4-dpap)(H_(2)O)]n 2n+via hydrogen-bonding *** 1 possesses satisfactory specifi c capacitance of 1512.4 F·g^(−1)(current density:1 A·g^(−1))and good cycling stability(90.8%after 1000 cycles).Moreover,1 represents a promising amperometric sensor for measurement of Cr(Ⅵ)with low detection limit(0.042μmol·L^(−1))and high *** insertion ofβ-Mo_(8)anions between the unique 2D metal−organic networks improves the active area of polyoxometalates,which further promotes electrochemical performance.

关键词： Homopolymolybdate Metal–organic network Pyrazole-amide-derived bis(pyridyl)ligand Supercapacitor Electrochemical sensor

Ore Geology,H-O-C Isotopes and 40Ar-39Ar Dating of the Wutonggou Iron Deposit,Eastern Tianshan,NW China:Implications for the Source,Timing,and Genesis of Hydrothermal Mineralization in a Sedimentary Iron Deposit

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Journal of Earth Science 2024年第4期35卷 1170-1185页

作者： chun-Long wang Yi-Tian wang State Key Laboratory of Geological Processes and Mineral Resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan430074China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing100037China

The Wutonggou iron deposit is located in the well-known iron metallogenic belt in the eastern Tianshan,NW China,and has been regarded as a sedimentary iron *** hydrothermal overprinting could play indispensable roles in the formation of high-grade iron ores in sedimentary iron deposits,previous studies mainly focused on sedimentary-related iron mineralization,while the nature and contribution of hydrothermal fluids are poorly ***,an integrated study of ore geology,H-O-C isotopes and^(40)Ar-^(39)Ar dating,is conducted on the Wutonggou deposit,in order to reveal the features,source,and timing of hydrothermal *** studied deposit includes two mining sections namely the Jianshan and ***δ^(18)O values of early magnetite from the Jianshan section range from+3.0‰to+5.8‰that nearly consistent with classic magmatic magnetite,while increase to 6.3‰-8.0‰in the late *** from the two sections shows comparable H-O isotopic compositions and identical fractionation trends,and is plotted in or periphery to the primary magmatic water *** from the two sections are broadly similar in carbon and oxygen isotopic compositions,and siderite from the Wutonggou section is plotted in the same ***,comparable stable isotopic compositions and evolution trends indicate similar magmatic fluids contributed hydrothermal iron mineralization in the two mining ***,water-rock interactions of varying degrees generated distinct mineralization styles in the Jianshan and Wutonggou sections,and caused the isotopic fractionation in late *** extracted from a hydrothermal siderite ore yielded a^(40)Ar-^(39)Ar plateau age of 299.5±2.0 Ma,indicates the timing of hydrothermal iron mineralization is corresponding to the emplacement of vicinity *** together,the hydrothermal mineralization in the Wutonggou iron deposit was the product of remobilization and upgrading of early sedimentary iron ores,a

关键词： iron deposits H-O-C isotopes 40Ar-39Ar dating sedimentary iron deposits Wutonggou iron deposit eastern Tianshan

Pb induced dislocation defects of PtCo systems: Strain-triggered oxygen reduction reaction for PEMFC

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Nano Research 2024年第4期17卷 2462-2472页

作者： chun Jin Qiheng wang Jingjun Liu Beijing Key Laboratory of Electrochemical Process and Technology for Materials Beijing 100029China Beijing University of Chemical Technology Beijing 100029China

Design and development of advanced electrocatalysts with high performance and low Pt consumption are crucial for reducing the kinetic energy barrier of the cathode oxygen reduction reaction(ORR)and improving the efficiency of proton exchange membrane fuel cells(PEMFC).In this study,we demonstrate a Pb-modulated PtCo system for efficient ORR,in which the inclusion of Pb in ternary alloys induces dislocation defects due to the significant difference in atomic ***-PtCoPb was confirmed to exhibit significantly higher ORR activity and stability in acidic *** practical PEMFC applications,it outperforms the corresponding commercial Pt/C with a mass activity of 0.58 A·mgPt^(-1),making it a promising alternative to state-of-the-art Pt-based *** combination of experimental results and density functional theory(DFT)calculations offers valuable atomic-level insights into the dislocation *** with a larger atomic radius is located in the lattice stretching region below the dislocation slip plane,forming a structure similar to a Cottrell atmosphere,which reduces the dislocation energy and puts the system in a lower energy *** Cottrell atmosphere pins the dislocation structure and stabilizes the ternary *** adjusting the amount of added Pb,a moderate level of dislocation density induces a tuned strain effect,thereby enhancing the electrocatalytic mechanism by optimizing the electronic structure of the alloy surface and the adsorption and desorption of oxygen *** work provides valuable insights into the design and development of lattice dislocation defect structures to trigger strain effects for improving ORR performance.

关键词： dislocation defect strain effect Pb-modulated oxygen reduction reaction