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Synthesis and characterization of two-dimensional lead-free(K, Na)NbO3 micro/nano piezoelectric structures

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Journal of Advanced Ceramics 2020年第1期9卷 27-34页

作者： Li-Qian cheng Mei feng Yiwen SUN Zhen ZHOU ze xu State Key Laboratory of Coal Resources and Safe Mining Department of Materials Science and EngineeringChina University of Mining&Technology(Beijing)Beijing 100083China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Two-dimensional(2 D)lead-free(K,Na)Nb O3(KNN)micro/nano structures with controllable K/Na ratio were successfully fabricated via a two-step molten salt synthesis(MSS).In this work,the reaction factors,including the proportion of molten salts,the types of carbonates,the sintering temperature,and the sintering time,were discussed in detail and the optimized condition was *** microstructure of KNN was confirmed by confocal Raman spectroscopy,while piezoresponse force microscopy(PFM)was applied to measure three-dimensional(3 D)morphology and piezoelectric properties of KNN *** as-synthesized KNN platelets apparently possess anisotropic morphology and uniform structure,the size of which reaches 5–20μm in length/width and 0.5–1μm in *** should be noted that the K/Na ratios of the KNN crystals are basically consistent while the proportion of salts changes within a certain *** enrichment of Na element in the products is also observed,which owes to the smaller ionic radius of Na+comparing to that of K+.This result provides a reference for the further preparation of textured ceramics and flexible piezoelectric generators.

关键词： (K,Na)NbO3(KNN) lead-free two-dimensional(2D)structure piezoelectric property

Passive Control of Flow-Induced Vibration(FIV)by Helical Strakes for Two Staggered Flexible Cylinders

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China Ocean Engineering 2021年第4期35卷 475-489页

作者： xu Wan-hai WANG Qi-cheng qin Wen-qi DU Zun-feng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China School of Civil Engineering Tianjin UniversityTianjin 300072China CIMC Offshore Co.Ltd Shenzhen 518000China

Helical strake is a widely-used device for passive flow-induced vibration(FIV)control of cylindrical *** is omnidirectional and can effectively reduce FIV response *** on the passive FIV control for cylindrical structures are mainly concerned with a single isolated cylinder,while the influence of wake interference between multiple cylinders on FIV suppression devices is less considered up to *** engineering applications,multiple flexible cylinders with large aspect ratios can be subjected to complex flow forces,and the effects of wake interference are *** FIV suppression effect of helical strake of a common configuration(17.5D pitch and 0.25D height,where D is the cylinder diameter)in two staggered cylinders system is still *** paper systematically studied the FIV response of multiple cylinders system fitted with the helical strakes by model *** relative spatial position of the two cylinders is fixed at S=3.0D and T=8.0D,which ensures the cylindrical structures in the flow interference *** experimental results show that the helical strakes effectively reduce the FIV response on staggered upstream cylinder,and the suppression efficiency is barely affected by the smooth or straked downstream *** corresponding FIV suppression efficiency on the downstream cylinder is remarkably reduced by the influence of the upstream wake *** wake-induced vibration(WIV)phenomenon is not observed on the staggered downstream cylinder,which normally occurs on the downstream straked cylinder in a tandem arrangement.

关键词： flow-induced vibration(FIV) passive control helical strakes flexible cylinders staggered arrangement

Nanosheet-coated synthetic wood with enhanced flame-retardancy by vacuum-assisted sonocoating technique

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Nano Research 2022年第10期15卷 9440-9446页

作者： Zhi-Yuan Ma Xiao-feng Pan ze-Lai xu Zhi-Long Yu Bing qin Yi-Chen Yin Yu-cheng Gao Shu-Hong Yu Department of Chemistry Institute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&ChemistryHefei National Laboratory for Physical Sciences at the MicroscaleInstitute of EnergyHefei Comprehensive National Science CenterUniversity of Science and Technology of ChinaHefei 230026China Department of Modern Mechanics University of Science and Technology of ChinaHefei 230027China

Compared to natural woods,synthetic woods have superior mechanical stability,thermal insulation,and flame retardancy owing to their hierarchically cellular microstructures and intrinsic advantages of the thermosetting *** the long-time fire resistance is very important to the practical *** this study,we present a novel coating strategy by a vacuum-assisted sonication technique(sonocoating)with a rectorite nanosheet dispersion to create a uniform nanocoating on the channel walls of synthetic *** to ultrasonic energy and vacuum pressure,the nanosheet dispersion can penetrate deep down to form a layered nanocoating on the channel *** coated synthetic woods can withstand fire(400-600℃)for more than 10 min with 62%mass retainment,surpassing uncoated synthetic woods and natural ***,as a lightweight and strong composite with enhanced flame-retardant performance,the coated synthetic woods have huge potential applications in safe and energy-efficient buildings.

关键词： synthetic wood sonocoating vacuum infiltration rectorite nanosheets flame-retardant

Effects of argon blowing at tundish upper nozzle on multiphase flow behavior in nozzle

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Journal of Iron and Steel Research International 2022年第4期29卷 588-600页

作者： xu-feng qin Chang-gui cheng Yang Li Wei-li Wu Yan Jin The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina

In continuous casting,the argon blowing at the tundish upper nozzle is usually used to prevent nozzle clogging,whose effect is closely related to the migration of argon bubbles and the flow behavior of the liquid steel in the ***,to investigate the effects of argon blowing at the tundish upper nozzle on multiphase flow behavior in nozzle,a threedimensional model of the tundish–nozzle–mold was established for numerical *** results indicate that the argon bubbles injected from the inner wall of the tundish upper nozzle first move downward along the nozzle wall under the action of the liquid *** the distance from the tundish upper nozzle increases,the argon bubbles gradually diffuse to the center of the *** with no argon blowing,the liquid steel velocity increases in the center of the nozzle and decreases near the wall with argon *** increasing the argon flow rate,the concentration of bubbles in the nozzle increases,and the process of bubble group diffusion to the center region of the nozzle speeds *** in turn increases the liquid steel velocity at the center of the nozzle but reduces near the *** increasing the casting speed,the concentration of bubbles in the nozzle decreases,the length of the bubble group near the nozzle wall is extended,and the liquid steel velocity at the center region and near-wall region of the nozzle *** mechanism of argon blowing at the tundish upper nozzle to prevent nozzle clogging is mainly realized by the isolation effect of the argon bubble group on the inner wall of the nozzle.

关键词： Argon blowing Tundish upper nozzle Nozzle clogging Numerical simulation

Flow and heat transfer of liquid slag in a continuous casting mold

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Journal of Iron and Steel Research International 2019年第9期26卷 926-940页

作者： Hai-biao Lu Chang-gui cheng Yang Li xu-feng qin Yan Jin The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081HubeiChina

A three-dimensional mathematical model for coupled liquid steel and liquid slag was established to study the flow and heat transfer behavior of liquid slag. Based on the volume of fluid method and the heat transfer model, the effect of different casting parameters on the flow and heat transfer of the liquid slag was investigated. The results show that there are two different size recirculation zones of the liquid slag layer on the liquid steel in the mold center plane, extending from the submerged entry nozzle to the mold narrow face. With the increase in the casting speed and the decrease in the viscosity of the mold flux, the overall velocity and the temperature of the liquid slag increase. With the increase in the inclination angle and the submergence depth of the submerged entry nozzle, the temperature of the liquid slag decreases, and the velocity decreases near the mold narrow face and increases in the vicinity of the submerged entry nozzle. The inactive flow field and the low temperature of liquid slag within 100 mm of the submerged entry nozzle may intensify the surface longitudinal cracking sensitivity of the slab. When the lubrication and heat transfer are well regulated between the surface of mold and the mold flux film, low casting speed, large inclination angle and submergence depth of the submerged entry nozzle are beneficial for reducing the possibility of a slab surface longitudinal crack.

关键词： Continuous casting Liquid slag Flow Heat transfer Surface longitudinal cracking sensitivity Mathematical simulation

Different Gene Networks Are Disturbed by Zika Virus Infection in A Mouse Microcephaly Model

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Genomics, Proteomics & Bioinformatics 2020年第6期18卷 737-748页

作者： Yafei Chang Yisheng Jiang Cui Li qin Wang feng Zhang cheng-feng qin qing-feng Wu Jing Li Zhiheng xu Department of Bioinformatics and Biostatistics School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Molecular Developmental Biology CAS Center for Excellence in Brain Science and Intelligence TechnologyInstitute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Department of Virology State Key Laboratory of Pathogen and BiosecurityBeijing Institute of Microbiology and EpidemiologyBeijing 100071China Parkinson’s Disease Center Beijing Institute for Brain DisordersBeijing 100101China University of Chinese Academy of Sciences Beijing 100101China

The association of Zika virus(ZIKV)infection with microcephaly has raised alarm *** causal link has been confirmed in different animal models infected by ***,the molecular mechanisms underlying ZIKV pathogenesis are far from ***,we performed global gene expression analysis of ZIKV-infected mouse brains to unveil the biological and molecular networks underpinning *** found significant dysregulation of the sub-networks associated with brain development,immune response,cell death,microglial cell activation,and autophagy amongst *** provided detailed analysis of the related complicated gene networks and the links between ***,we analyzed the signaling pathways that were likely to be *** report provides systemic insights into not only the pathogenesis,but also a path to the development of prophylactic and therapeutic strategies against ZIKV infection.

关键词： Zika virus Brain development Microcephaly Gene network Signaling pathway

Tailoring the microstructure and improving the discharge properties of dilute Mg-Sn-Mn-Ca alloy as anode for Mg-air battery through homogenization prior to extrusion

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Journal of Materials Science & Technology 2021年第1期60卷 77-89页

作者： Xiong-jie Gu Wei-li cheng Shi-ming cheng Yan-hui Liu Zhi-feng Wang Hui Yu ze-qin Cui Li-fei Wang Hong-xia Wang School of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China Shanxi Key Laboratory of Advanced Magnesium-Based Materials Taiyuan University of TechnologyTaiyuan 030024China School of Materials Science and Engineering Hebei University of TechnologyTianjin 300132China

Mg-0.5Sn-0.5Mn-0.5Ca(wt.%) alloys with different microstructures are designed through casting and extrusion with and without homogenization treatment prior to extrusion(HPE).The influence of HPE treatment on the microstructural characteristics and resultant discharge properties of Mg-Sn-Mn-Ca alloy in extruded condition as anode for Mg-air battery was *** treatment exerts a prominent effect on the grain structure and orientation,distribution of the second phase particles as well as the dislocation density of the extruded *** HPE alloy exhibits a distinctly high cell voltage together with specific energy compared with that of Non-HPE *** discharge tests confirm that the HPE alloy possesses a more excellent discharge activity and more stable discharge process than the NonHPE *** results demonstrate that the HPE alloy is an attractive anode material for Mg-air battery with long-term storage and under intermittent discharge.

关键词： Mg-air battery Homogenization prior to extrusion Microstructure Discharge property Intermittent discharge

AP-1 and SP1 trans-activate the expression of hepatic CYP1A1 and CYP2A6 in the bioactivation of AFB1 in chicken

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Science China(Life Sciences) 2024年第7期67卷 1468-1478页

作者： Jiang Deng Jia-cheng Yang Yue feng ze-Jing xu Kamil Kuča Meng Liu Lv-Hui Sun State Key Laboratory of Agricultural Microbiology Hubei Hongshan LaboratoryFrontiers Science Center for Animal Breeding and Sustainable ProductionCollege of Animal Sciences and TechnologyHuazhong Agricultural UniversityWuhan 430070China Department of Chemistry Faculty of ScienceUniversity of Hradec KraloveHradec Kralove 50003Czech Republic

Dietary exposure to aflatoxin B1(AFB1)is harmful to the health and performance of domestic *** hepatic cytochrome P450s(CYPs),CYP1A1 and CYP2A6,are the primary enzymes responsible for the bioactivation of AFB1to the highly toxic exo-AFB1-8,9-epoxide(AFBO)in ***,the transcriptional regulation mechanism of these CYP genes in the liver of chicks in AFB1metabolism remains ***-luciferase reporter assay,bioinformatics and site-directed mutation results indicated that specificity protein 1(SP1)and activator protein-1(AP-1)motifs were located in the core region-1,063/-948,-606/-541 of the CYP1A1 promoter as well as-636/-595,-503/-462,-147/-1 of the CYP2A6 ***,overexpression and decoy oligodeoxynucleotide technologies demonstrated that SP1 and AP-1 were pivotal transcriptional activators regulating the promoter activity of CYP1A1 and ***,bioactivation of AFB1to AFBO could be increased by upregulation of CYP1A1 and CYP2A6 expression,which was trans-activated owing to the upregulation of AP-1,rather than SP1,stimulated by AFB1-induced reactive oxygen ***,nano-selenium could reduce ROS,downregulate AP-1 expression and then decrease the expression of CYP1A1 and CYP2A6,thus alleviating the toxicity of *** conclusion,AP-1 and SP1 played important roles in the transactivation of CYP1A1 and CYP2A6 expression and further bioactivated AFB1to AFBO in chicken liver,which could provide novel targets for the remediation of aflatoxicosis in chicks.

关键词： aflatoxin B1 CYP1A1 CYP2A6 SP1 AP-1 transcriptional activation

Development and characterization of a clinical strain of Coxsackievirus A16 and an eGFP infectious clone

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Virologica Sinica 2015年第4期30卷 269-276页

作者： chenglin Deng Xiaodan Li Siqing Liu Linlin xu Hanqing Ye cheng-feng qin Bo Zhang Key Laboratory of Special Pathogens and Biosafety Wuhan Institute of Virology Chinese Academy of Sciences University of Chinese Academy of Sciences State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and Epidemiology

Coxsackievirus A16(CA16) is one of the major causes of hand, foot, and mouth disease(HFMD) worldwide, which is a common illness that affects children. The frequent occurrence of HFMD outbreaks has become a serious public health problem in Asia. Therefore, it is important to understand the pathogenesis and replication of CA16. In this study, a stable infectious c DNA clone of an epidemic strain of Coxsackievirus A16(CA16) was assembled, and subsequently a reporter virus(e GFP-CA16) was constructed by inserting the e GFP gene between the 5'-UTR and the N-terminus of VP4, with the addition of a 2A protease cleavage site(ITTLG) at its C-terminus. This was transfected into Vero cells to generate infectious recombinant viruses. The growth characteristics and plaque morphology, in vitro, in mammalian cells were found to be indistinguishable between the parental and recombinant viruses. Although the e GFP-CA16 showed smaller plaque size as compared to recombinant CA16, both were found to exhibit similar growth trends and EC50 of NITD008. In summary, this stable infectious c DNA clone should provide a valuable experimental system to study CA16 infection and host response. The e GFP-CA16 is expected to provide a powerful tool to monitor e GFP expression in infected cells and to evaluate the antiviral activity of potential antiviral agents in the treatment of CA16 infections.

关键词： Coxsackievirus A16(CA16) infectious cDNA clone rep