Investigation of temperature sensitivity of actuation performance for piezoelectric fiber composites

Lin, Xiujuan,Chen, Haiyan,Ma, Yupeng,Fisher, John G.,Huang, Shifeng,Zhang, Dou,Cheng, Xin Elsevier 2017 CERAMICS INTERNATIONAL Vol.43 No.13

<P><B>Abstract</B></P> <P>Piezoelectric fiber composites (PFCs) suffer an extremely wide range of temperatures when used in various aerospace structures where temperature effects on the mechanical properties of PFCs are important. In this paper, the actuation performances of PFCs were studied when they were exposed to environmental temperatures from −15°C to 80°C. The results showed that the actuation performance of PFCs was greatly dependent on the environmental temperature. The free strain values and the calculated piezoelectric coefficients d<SUB>33</SUB> and d<SUB>31</SUB> were initially enhanced with the increase of temperature due to the restricted movement of epoxy molecule in the glassy state. The glass transition temperature range of the composite was broadened due to a large number of small pores on the surface of the Pb(Zr,Ti)O<SUB>3</SUB> (PZT) fibers, when the epoxy molecules inside the pores had different transition behaviors compared with those outside the pores. The actuation performance including free strain performance and actuation capability, as well as the piezoelectric coefficients d<SUB>33</SUB> and d<SUB>31</SUB> decreased as the temperature increased above room temperature, since the deformation of epoxy molecules in the viscoelastic state was irreversible.</P>

Evaluation of freezing tolerance in Actinidia germplasm based on relative electrolyte leakage

Shihang Sun,Xiujuan Qi,Ran Wang,Miaomiao Lin,Jinbao Fang 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.4

Cold stress in winter can have a disastrous eff ect on kiwifruit yield and aff ect geographical distribution. However, freezingtolerance in Actinidia genotypes remains largely unknown. Here, we report changes in metabolite content and enzymeactivity in the shoots of Actinidia genotypes exposed to low-temperature stress (− 5 °C, − 10 °C, − 15 °C, − 20 °C, − 25 °Cand − 30 °C). Moreover, the relative electrolyte leakage method was used to evaluate the freezing tolerance of kiwifruitgermplasm; 51 genotypes from 16 species of Actinidia were evaluated in total. The data revealed that relative electrolyteleakage, proline (Pro), soluble protein, and catalase (CAT) activity changed with diff erent low temperatures. Results showedthat among 16 species, A. kolomikta , A. polygama , and A. arguta had lower LT50 than other species. A. arguta , originatingfrom the northeast of China, exhibited stronger freezing resistance than the ones from other places. There was little diff erencein freezing tolerance between A. chinensis and A. deliciosa . These fi ndings provide new insights into the freezing toleranceability and mechanisms of kiwifruit and further contribute to our understanding of the relationship between freezing toleranceand geographic distribution.

Enhanced dielectric properties and discharged energy density of composite films using submicron PZT particles

Chen, Guanliang,Lin, Xiujuan,Li, Jianan,Fisher, John G.,Zhang, Yan,Huang, Shifeng,Cheng, Xin Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.13

<P><B>Abstract</B></P> <P>Flexible dielectric composite films are highly desirable materials with potential application in capacitors due to their high energy density and discharged efficiency. However, agglomeration induced by the large surface energy of nanoparticles and their large dielectric losses are unfavorable to the improvement of energy density. Submicron lead zirconate titanate (PZT) particles have shown great potential as filler in achieving a high energy storage capacity because of their excellent dielectric properties and good dispersion. In this work, calcined PZT particles were used to prepare PZT/polyvinylidene fluoride (PVDF) composite films. The results showed that composite films of high quality could be obtained even with high contents of submicron PZT particles. The introduction of PZT particles significantly improved the dielectric performance of composite films compared with that of the pristine PVDF film. The discharged energy density of composite films with 10 vol% PZT particles achieved 6.41 J/cm<SUP>3</SUP> at 250 kV/mm. A high efficiency of 87.25% was obtained at 50 kV/mm. These findings confirm the feasibility of PZT particles as inorganic filler in composite films for energy storage applications.</P>

Comparative analysis of physiological traits of three Actinidia valvata Dunn genotypes during waterlogging and post-waterlogging recovery

Zhi Li,Yunpeng Zhong,Danfeng Bai,Miaomiao Lin,Xiujuan Qi,Jinbao Fang 한국원예학회 2020 Horticulture, Environment, and Biotechnology Vol.61 No.5

Kiwifruit ( Actinidia sp.) vines are poorly adapted to waterlogging stress. Actinidia valvata is more tolerant against waterloggingstress than Actinidia deliciosa , and the latter contains some common rootstocks that are frequently used in kiwifruit cultivation. Little is known about the responses of A. valvata genotypes against waterlogging stress and during post-waterloggingrecovery. Here, we compared physiological traits of three A. valvata genotypes (KR1, KR3, and KR5) during waterloggingstress and recovery. Kiwifruit vines displayed water loss, a decline in the net photosynthetic rate, and inhibited shoot elongationduring waterlogging. These three genotypes could endure long-term waterlogging owing to their unique root systemconfi gurations as well as by sustaining carbohydrate reserves in the roots. Feeder roots of KR1 vines were damaged earlierand lost water more quickly than the other genotypes. Under the same stress, KR3 formed adventitious roots more rapidly,while KR5 had an improved ability to control water loss in above-ground tissues. After reoxygenation, growth of vineswas partially recovered due to water loss control, photosynthetic recovery, and carbohydrate replenishment. KR3 and KR5recovered their growth earlier and replenished more carbohydrates than KR1 after re-aeration. During waterlogging, both therelative water content and carbohydrate levels of vines can limit the recovery effi ciency after re-aeration. Our results revealedmutual and distinct responses of diff erent A. valvata genotypes during waterlogging stress and recovery and provided moreinsight into the physiological basis of their adaptation to waterlogging stress.

RPK118, a PX Domain-containing Protein, Interacts with Peroxiredoxin-3 through Pseudo-Kinase Domains

Long Yu,Lingling Liu,Chenyi Yang,Jian Yuan,Xiujuan Chen,Jianing Xu,Youheng Wei,Jingchun Yang,Gang Lin 한국분자세포생물학회 2005 Molecules and cells Vol.19 No.1

RPK118 is a sphingosine kinase-1-binding protein that has been implicated in sphingosine 1 phosphate-mediated signaling. It contains a PX (phox homology) domain and two pseudo-kinase domains, and co-localizes with sphingosine kinase-1 on early endosomes. In this study we identified a novel RPK118-binding protein, PRDX3 (peroxiredoxin-3), by yeast two-hybrid screening. The interaction between these proteins was confirmed by pull-down assays and co-immunoprecipitation experi-ments. Deletion studies showed that RPK118 inter-acted with PRDX3 through its pseudokinase domains, and with early endosomes through its PX domain. Dou-ble immunofluorescence experiments demonstrated that PRDX3 co-localized with RPK118 on early endosomes in COS7 cells. PRDX3 is a member of the antioxidant family of proteins synthesized in the cytoplasm and functioning in mitochondria. Our findings indicate that RPK118 is a PRDX3-binding protein that may be involved in transporting PRDX3 from the cytoplasm to its mitochondrial site of function or to other mem-brane structures via endosome trafficking

Reactive sintering of lead-free piezoelectric (K0.5Na0.5) NbO3 ceramics

Muhammad Umer FAROOQ,John G. Fisher,김진하,김대웅,신의철,김영훈,김지훈,문수현,이종숙,Xiujuan LIN,Dou Zhang 한양대학교 세라믹연구소 2016 Journal of Ceramic Processing Research Vol.17 No.4

In this paper, (K0.5Na0.5)NbO3 (KNN) ceramics are prepared by a simple and cost- effective reactive sintering method. Startingmaterials of K2CO3, Na2CO3 and Nb2O5 are mixed by ball-milling, pressed into pellets and sintered at 1080 oC, 1100 oC and1120 oC for between 0.25-3 hours. The Archimedes density of samples sintered at 1120 oC reached 91% of the theoreticaldensity after 30 min sintering time. All samples show a single phase perovskite structure after sintering. Samples sintered at1080 oC have a fine-grained microstructure whereas samples sintered at 1100 oC and 1120 oC show abnormal grain growth. Samples sintered at 1120 oC for 1 hour show dielectric, ferroelectric and piezoelectric properties comparable to those ofconventionally-sintered KNN. A conduction mechanism with activation energy of 0.62 eV for the high leakage in the KNNsystem was revealed by impedance spectroscopy.