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Journal of Materials Science & Technology 2023年第14期145卷 1-6页

作者： Cen Wang Xuan Ge Huiqing Fan Fan Yang Qiaodan Hu jianguo li Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Materials Science and Engineering Northwestern Polytechnical UniversityXi’an 710072China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Titanium dioxide(TiO_(2))has broad applications in photo(electro)catalysis,sensors,batteries,supercapacitors,pol-lutant degradation and so on[1-5].Pure TiO_(2)has a band gap of 3.0-3.2 eV,which limits its optical abso... 详细信息

关键词： Titanium size phase

Dynamic recrystallization-induced temperature insensitivity of yield stress in single-crystal Al1.2CrFeCoNi micropillars

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Science China(Technological Sciences) 2021年第1期64卷 11-22页

作者： HUANG RuiRui ZHANG Qian ZHANG Xuan li jianguo CAO TangQing YAO JiaHao XUE YunFei GAO HuaJian li XiaoYan Center for Advanced Mechanics and Materials Applied Mechanics LaboratoryDepartment of Engineering MechanicsTsinghua UniversityBeijing 100084China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Mechanical and Aerospace Engineering College of EngineeringNanyang Technological UniversitySingapore 639798Singapore Institute of High Performance Computing A*STARSingapore 138632Singapore

High-entropy alloys, a new class of metallic materials, exhibit excellent mechanical properties at high temperatures. In spite of the worldwide interest, the underlying mechanisms for temperature dependence of mechanical properties of these alloys remain poorly understood. Here, we systemically investigate the mechanical behaviors and properties of Al_(1.2)CrFeCoNi(comprising a body-centered cubic phase) and Al_(0.3)CrFeCoNi(comprising a face-centered cubic phase) single-crystal micropillars with three orientations([100], [110], and [111]) at temperatures varying from 300 to 675 K by using in situ compression of micropillars inside a scanning electron microscope. The results show that the yield stresses of Al_(1.2)CrFeCoNi micropillars are insensitive to temperature changes, and their flow stresses and work hardening rates increase slightly with increasing temperature from 300 to550 K, which differs from the typical temperature dependence of yield/flow stresses in metals and alloys. In contrast,Al_(0.3)CrFeCoNi micropillars exhibit typical thermal softening. Furthermore, it is found that the Al_(1.2)CrFeCoNi micropillars exhibit a transition from homogenous deformation to localized deformation at a critical temperature, while the Al_(0.3)CrFeCoNi micropillars always maintain a well-distributed and fine slip deformation. Detailed transmission electron microscopy analyses reveal that dynamic recrystallization(involving dislocation tangles, and formation of dislocation cell structures and sub-grains)plays a key role in the observed temperature insensitivity of the yield stress and increasing flow stress(and work hardening rate)with increasing temperature in the Al_(1.2)CrFeCoNi micropillars, and that thermally activated dislocation slip leads to thermal softening of the Al_(0.3)CrFeCoNi micropillars. The differences in deformation modes and temperature dependence of the mechanical properties between Al_(1.2)CrFeCoNi and Al_(0.3)CrFeCoNi essentially originate from the d

关键词： high entropy alloy temperature insensitivity dynamic recrystallization micropillar deformation twin

Operation, Analysis and Experiments of DC Transformers Based on Modular Multilevel Converters for HVDC Applications

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CSEE Journal of Power and Energy Systems 2019年第1期5卷 87-99页

作者： jianguo li Xianghong Zuo Yuming Zhao Xiuping Lv Jiuhe Wang College of Automation Beijing Information Science and Technology UniversityBeijing 100192China Beijing Electric Power Economic Research Institute Beijing 100055China Shenzhen Power Supply Company Shenzhen 518048China

This paper studies the operation,analysis and experiments of multilevel high frequency link transformers(MHFLT)based on modular multilevel converters(MMC)for high voltage DC *** multilevel dual active phase shift is proposed to operate the MHFLT using a high switching frequency,which brings about many advantages and makes the operation quite different from that of the traditional DC transformer(DCT)based on a dual active bridge and the fundamental frequency MMC widely used in flexible HVDC ***,MHFLT is suitable for high voltage levels,which is due to its good switching characterization,ability to cut itself off from an external fault,and it can also achieve redundancy operations when a sub-module fault *** this paper,the operation,modulation method,multilevel high frequency link voltage,current,and power characterization,high frequency commutation,and switching characterization are analyzed comprehensively;the pulse rotation and distributed delay control,and fault handling strategies of MHFLT are then ***,a prototype is built,and the experimental results verify the correctness and effectiveness of the proposed solution.

关键词： DC–DC converter DC transformer DC transmission high-frequency-link high voltage DC multilevel converter

Kinetic role of Cu content in reaction process, behavior and their relationship among Cu-Zr-C system

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Journal of Materials Science & Technology 2019年第10期35卷 2375-2382页

作者： Qiaodan Hu Xianrui Zhao Siyu Sun Hua Zheng Sheng Cao jianguo li Mengxian Zhang School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Scholl of Naval Architecture&Ocean Engineering Jiangsu Maritime InstituteNanjing 211170China Zhejiang Provincial Key Laboratory for Cutting Tools Taizhou UnniversityTaizhou 318000China Primary School of Education Chongqing Normal UniversityChongqing 400700China Monash Centre for Additive Manufacturing(MCAM) Monash UniversityClaytonVIC 3800Australia Jiangxi Province Engineering Research Center of Materials Surface Enhancing&Remanufacturing School of Mechanical and Materials EngineeringJiujiang UniversityJiujiang 332005China

The influence of Cu content on the reaction process, reaction behavior and obtained products in the Cu-ZrC system, as well as their relationships, were investigated. The results showed that Zr C was synthesized through the diffusion and dissolution of C into a Cu-Zr liquid. Increasing the Cu content enhanced the amount of Cu-Zr liquid formed at the early stage but decreased the amount of C atoms dissolving into the melt at unit time. Consequently, the ignition time initially decreased and then increased. Conversely, with an increased Cu content, the energy required for igniting the neighboring unreacted powders increased,while the heat released by the reaction and the dwell time of the compact at high temperatures *** effects then resulted in the reduction of combustion wave velocity, combustion temperature and Zr C particle size. Furthermore, the synthesis of ZrC is a multistage process, which provides a nonuniform distributed Zr C particle size. The sub-μm Zr C particle reinforced Cu matrix composite was fabricated by adding a ZrC-Cu master alloy prepared through a self-propagating high-temperature synthesis reaction into liquid Cu.

关键词： Self-propagating high-temperature synthesis Reaction process Reaction behavior Solidification

Brassinosteroids suppress ethylene-induced fruitlet abscission through LcBZR1/2-mediated transcriptional repression of LcACS1/4 and LcACO2/3 in litchi

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Horticulture Research 2021年第1期8卷 1527-1538页

作者： Xingshuai Ma Ye Yuan Caiqin li Qian Wu Zidi He jianguo li Minglei Zhao State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources China Litchi Research CenterSouth China Agricultural University510642 GuangzhouChina Guangdong litchi Engineering Research Center College of HorticultureSouth China Agricultural University510642 GuangzhouChina Ministry of Agriculture and Rural Affairs Key Laboratory of South China Horticultural Crop Biology and Germplasm Enhancement College of HorticultureSouth China Agricultural University510642 GuangzhouChina

Abscission in plants is tightly controlled by multiple phytohormones and the expression of various ***,whether the plant hormone brassinosteroids(BRs)are involved in this process is largely ***,we found that exogenous application of BRs reduced the ethylene-induced fruitlet abscission of litchi due to lower ethylene(ET)production and suppressed the expression of the ethylene biosynthetic genes LcACS1/4 and LcACO2/3 in the fruitlet abscission zone(FAZ).Two genes that encode the BR core signaling components brassinazole resistant(BZR)proteins,namely,LcBZR1 and LcBZR2,were ***1/2 were localized to the nucleus and acted as transcription ***,the LcBZR1/2 transcript levels were not changed during ET-induced fruitlet abscission,while their expression levels were significantly increased after BR ***,gel shift and transient expression assays indicated that LcBZR1/2 could suppress the transcription of LcACS1/4 and LcACO2/3 by specifically binding to their ***,ectopic expression of LcBZR1/2 in Arabidopsis significantly delayed floral organ abscission and suppressed ethylene ***,our results suggest that BRs suppress ET-induced fruitlet abscission through LcBZR1/2-controlled expression of genes related to ethylene biosynthesis in *** addition,similar results were observed in the Arabidopsis gain-of-function mutant bzr1-1D,which showed delayed floral organ abscission in parallel with lower expression of ACS/ACO genes and reduced ethylene production,suggesting that the mechanism of BZR-controlled organ abscission via regulation of ethylene biosynthesis might be conserved in Arabidopsis.

关键词： 1/2 transient suppress

Crystal Structure, Thermal Decomposition Behaviors and Sensitivity Properties of a Novel Energetic Compound [Co（DAT）6] （CIO4）2

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Chinese Journal of Chemistry 2011年第1期29卷 59-64页

作者： Qi, Shuyuan li, Zhimin Zhou, Zunning Cui, Yan Zhang, Guotao Zhang, Tonglai Zhang, jianguo Yang, li State Key Laboratory of Explosion Science and Technology Beijing Institute of Techonoly Beijing 100081 China

A novel energetic coordination compound [Co（DAT）6]（CIO4）2 has been synthesized by using 1,5-diaminotetrazole （DAT） as a ligand and its structure has been characterized using X-ray single crystal diffraction, elemental analysis and FT-IR spectroscopy. The central cobalt（II） cation is coordinated by six N atoms from six DAT molecules to form a six-coordinated and distorted octahedral structure. Di-dimension layer structure was formed by the extensive intermolecular hydrogen bonds between DAT ligands and CIO4 anions along a-axis and b-axis. Thermal decomposition mechanism of [Co（DAT）6]（CIO4）2 was investigated based on differential scanning calorimetry （DSC）, thermogravimetric analysis （TGA） and Fourier transform infrared （FF-IR） spectra. The kinetic parameters of the first exothermic process were studied by applying the Kissinger＇s and Ozawa-Doyle＇s methods. Additionally, the sensitivities of this complex were tested. The results of all the studies show that [Co（DAT）6]（CIO4）2 has an extreme potential application as an energetic material.

关键词： cobalt crystal structure 1,5-diaminotetrazole thermochemistry sensitivity properties

Deciphering the glass-forming ability of Al_(2)O_(3)-Y_(2)O_(3)system from temperature susceptibility of melt structure

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Journal of Materials Science & Technology 2024年第18期185卷 48-57页

作者： Pingsheng Lai Xuan Ge Caijuan Shi Jianqiang li Fan Yang Wenquan Lu jianguo li Qiaodan Hu Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Chemistry and Bioscience Aalborg UniversityAalborg 9220Denmark Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Despite its significance in both fundamental science and industrial applications,the glass-forming tran-sition in the Al_(2)O_(3)-Y_(2)O_(3)(AY)refractory system is not yet fully understood due to the elusive structure evolution upon ***,atomic-scale structural changes in AY-bearing melts with different compo-sitions and temperatures are tracked by employing in situ high-energy synchrotron X-ray diffraction and empirical potential structure refinement *** find that the glass-forming abilities(GFA)of AY-bearing melts are intriguingly correlated with the dependence of melt structure on *** the case of the Al_(2)O_(3)and Y_(3)A_(l5)O_(12)(YAG),the observed large structural changes from superheating to under-cooling melt(i.e.,higher temperature susceptibility)correspond to a low ***,the 74Al_(2)O_(3)-26Y_(2)O_(3)(AY26)melt,with the smallest temperature susceptibility,exhibits the highest *** models illustrate that the temperature susceptibility of melt is associated with its atomic arrangement,especially the stability of cation-cation pairs.A balanced network(in AY26 melt),where the unsteady OAl3 tri-clusters are minimized and steady apex-to-apex connections between adjacent network units are abundant,contributes to stabilizing cationic ***,in turn,fosters the formation of large-sized Al-O-Al rings,which topologically facilitates the subsequent glass-forming *** findings provide new structural insight into the GFA of AY-bearing melts and may expand to other unconventional glass-forming systems to accelerate glassy materials design.

关键词： Glass-forming ability Al_(2)O_(3)-Y_(2)O_(3)glasses Melt structure High-energy synchrotron X-ray diffraction Aerodynamic levitation EPSR simulation

Clinical and Genetic Characteristics of Alagille Syndrome in Adults

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Journal of Clinical and Translational Hepatology 2023年第1期11卷 156-162页

作者： jianguo li Haicong Wu Shuru Chen Jiahui Pang Heping Wang Xinhua li Weiqiang Gan Department of Infectious Diseases The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdongChina Guangdong Key Laboratory of liver Disease Research The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdongChina Department of Hepatobiliary Medicine 900th Hospital of Joint Logistics Support ForceFuzong Clinical Medical College of Fujian Medical UniversityFuzhouFujianChina

Background and Aims:Alagille syndrome(AGS)is an autosomal dominant multisystem disorder caused by mutations in the JAG1 and NOTCH2 *** has been rarely reported in adult patients,mainly because its characteristics in adults are *** study aimed to improve the understanding of adult AGS by a descriptive case ***:Eight adults diagnosed with AGS at our hospital between June 2016 and June 2019 were included in the *** data,biochemical results,imaging results,liver histopathology,and genetic testing were ***:Three female and five male patients with a median age of 24.5 years at the time of diagnosis were included in the *** clinical manifestations were adult-onset(62.5%,5/8),cholestasis(50%,4/8),butterfly vertebrae(62.5%,5/8),systolic murmurs(12.5%,1/8),typical facies(12.5%,1/8),posterior embryotoxon,and renal abnormalities(0/8).Genetic sequencing showed that all patients had mutations,with four occurring in the JAG1 gene and four in the NOTCH2 *** were substitution mutations,one was a deletion mutation,and one was a splicing *** had been previously reported;but the others,one JAG1 mutation and two NOTCH2 mutations were unique and are reported here for the first ***:The clinical manifestations highlighted by the current diagnostic criteria for most adults with AGS are *** who do not meet the criteria but are highly suspicious of having AGS need further evaluation,especially genetic testing.

关键词： Alagille syndrome Clinical features JAG1 NOTCH2 Adult

A miniature liquid helium temperature JT cryocooler for space application

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Science China(Technological Sciences) 2014年第11期57卷 2236-2240页

作者： QUAN Jia ZHOU ZhenJun liU YanJie li jianguo MA YueXue liANG JingTao Technical Institute of Physics and Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences

Along with the development of space science and technology,miniature liquid helium temperature long life cryocooler is a focus subject in cryogenic *** it is the precondition of space detection researches,institutions of space in many countries do the research on *** this article,we designed a compound cooling system.A three-stage high frequency thermal coupled pulse tube cryocooler was used to precool a Joule-Thomson(JT)*** system has no moving parts at low temperatures and is hence suitable for space *** helium temperature was successfully achieved in both open loop and closed cycle *** the closed cycle experiment,when 473 W electric power was inputted,the cooling system reached a no-load temperature of 4.4 K,and a cooling capacity of 11.6 mW was provided at 4.54 *** is the first miniature liquid helium temperature JT cryocooler in China and the research achievement paves a way for the space application of ultra-long wave infrared detection and THz technologies.

关键词： liquid helium temperature JT cryocooler space application

A closed loop 2.65 K hybrid JT cooler for future space application

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Science China(Technological Sciences) 2019年第2期62卷 361-364页

作者： MA YueXue QUAN Jia WANG Juan liU YanJie li jianguo liANG JingTao Key Laboratory of Space Energy Conversion Technologies Technical Institute of Physics and Chemistry Chinese Academy of Sciences

Cryogenics and its applications in space have made a remarkable amount of progresses over the last few *** the area of space astronomy,some electronic detectors should be cooled to 1–4 K to improve their performance[1,2].So the miniature 1–4 K cryocooler for space application has become a key field for cryogenic research in recent *** view of their flexibility and relatively higher efficiency,hybrid JT cryocoolers are widely used in space detectors working at below 4 *** fact,nearly all the space applications of mechanical cryocoolers working at the temperature of 1–4 K,having been launched or under development are hybrid JT cryocoolers[2–6].

关键词： Figure