Combining In Situ Synchrotron X‐Ray Diffraction and Absorption Techniques with Transmission Electron Microscopy to Study the Origin of Thermal Instability in Overcharged Cathode Materials for Lithium‐Ion Batteries

Nam, Kyung&#x2010,Wan,Bak, Seong&#x2010,Min,Hu, Enyuan,Yu, Xiqian,Zhou, Youngning,Wang, Xiaojian,Wu, Lijun,Zhu, Yimei,Chung, Kyung&#x2010,Yoon,Yang, Xiao&#x2010,Qing WILEY‐VCH Verlag 2013 Advanced Functional Materials Vol.23 No.8

<P><B>Abstract</B></P><P>The thermal instability of the cathode materials in lithium‐ion batteries is an important safety issue, requiring the incorporation of several approaches to prevent thermal runaway and combustion. Systematic studies, using combined well‐defined in situ techniques, are crucial to obtaining in‐depth understanding of the structural origin of this thermal instability in overcharged cathode materials. Here time‐resolved X‐ray diffraction, X‐ray absorption, mass spectroscopy, and high‐resolution transmission electron microscopy during heating are combined to detail the structural changes in overcharged Li<SUB><I>x</I></SUB>Ni<SUB>0.8</SUB>Co<SUB>0.15</SUB>Al<SUB>0.05</SUB>O<SUB>2</SUB> and Li<SUB><I>x</I></SUB>Ni<SUB>1/3</SUB>Co<SUB>1/3</SUB>Mn<SUB>1/3</SUB>O<SUB>2</SUB> cathode materials. By employing these several techniques in concert, various aspects of the structural changes are investigated in these two materials at an overcharged state; these include differences in phase‐distribution after overcharge, phase nucleation and propagation during heating, the preferred atomic sites and migration paths of Ni, Co, and Mn, and their individual contributions to thermal stability, together with measuring the oxygen release that accompanies these structural changes. These results provide valuable guidance for developing new cathode materials with improved safety characteristics.</P>

Transcriptome profiles of tomato plants after neutron irradiation and infection with TYLCV

Zhou, Yujie,Cho, Won Kyong,Byun, Hee&#x2010,Seong,Kil, Eui&#x2010,Joon,Bak, Sang&#x2010,In,Moon, Dal&#x2010,Ho,Chavan, Vivek,Park, Tae&#x2010,Sun,Lee, Sukchan,Hong, Seung&#x2010,Woo Blackwell Publishing Ltd 2019 Physiologia plantarum Vol.165 No.2

<P>Ionizing radiation is ubiquitous in the environment and can cause mutagenesis in living organisms. In this study, we examined the effects of neutron irradiation on tomato plants. Neutron irradiation decreased tomato germination rates, but most irradiated tomato plants did not show any significant phenotype. However, tomato mutants infected by <I>Tomato yellow leaf curl virus</I> (TYLCV) displayed resistance against TYLCV compared to the wild type (WT), which showed disease symptoms. RNA‐Seq data demonstrated that the expression profiles of eight tomato mutants were significantly different from that of the WT. The transcriptomes obtained from presoaked seeds were highly altered compared to those of dry seeds. Increased irradiation time resulted in severe changes in the tomato transcriptome; however, different neutron irradiation intensities affected the expressions of different sets of genes. A high number of single‐nucleotide polymorphisms in tomato transcriptomes suggest that neutron irradiation strongly impacts plant transcriptomes. The transition/transversion values among mutants were almost constant and were lower than that of the non‐irradiated sample (WT), suggesting that neutron irradiation caused an effect. Taken together, this is the first report showing the effects of neutron irradiation on tomato plants by transcriptome analyses.</P>

A Multifunction Heterojunction Formed Between Pentacene and a Single‐Crystal Silicon Nanomembrane

Seo, Jung&#x2010,Hun,Oh, Tae&#x2010,Yeon,Park, Jungho,Zhou, Weidong,Ju, Byeong&#x2010,Kwon,Ma, Zhenqiang WILEY‐VCH Verlag 2013 Advanced functional materials Vol.23 No.27

<P><B>Abstract</B></P><P>A mesh patterned n‐type single‐crystalline silicon nanomembrane (SiNM) created from a silicon‐on‐insulator (SOI) wafer is complementally combined with a p‐type pentacene layer to form a heterogeneous p‐n junction on a flexible plastic substrate. Excellent rectifying characteristics are obtained from the heterogeneous p‐n diode. The diode also exhibits photosensitivity at visible wavelengths with a photo‐to‐dark current ratio exceeding four orders, a responsivity of 0.7 A/W, and an external quantum efficiency of 21.9% at 633 nm. Over 60% average transmittance in the visible spectrum is measured from the heterogeneous multilayer junction on a plastic substrate. Outstanding mechanical bending characteristics are observed with up to 1.08% of strain applied to the diode. These results suggest that organic‐inorganic heterogeneous integration may be a viable strategy to build flexible organic‐inorganic heterojunction devices and thus enable a number of novel multifunctional applications.</P>

XRD studies on phase formation and the crystallite structure of BaTiO3 synthesized by HBM: the effect of calcination temperature

X.M. Chen,Y. Zhang,W.W. Kong,X.B. Bian,J.P. Zhou,P. Liu 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.4

Barium titanate (BaTiO3, or BT) powders were synthesized via a solid state reaction of BaCO3-TiO2 by combining a highenergy ball milling (HBM) technique and a calcination method. Using X-ray diffraction (XRD) methods with a Rietveld refinement, the effects of calcination temperature on the phase formation and crystallite structure of BT powders were studied. It is found that by means of HBM the synthesis temperature for obtaining BT single phase is decreased to 960 oC, which is much lower than that required by the conventional solid-state reaction process, and the crystallite structure of BT is in the (pseudo)cubic form. As the calcination temperature is increased to 980 oC, the structure of BT crystallites transforms from the (pseudo)cubic to the tetragonal form. With an increase in the calcination temperature, both the tetragonality (c/a-1) and crystallite size are increased.

Physciosporin suppresses the proliferation, motility and tumourigenesis of colorectal cancer cells

Ta&#x15f,, &#x130,sa,Han, Jin,Park, So-Yeon,Yang, Yi,Zhou, Rui,Gamage, Chathurika D.B.,Van Nguyen, Tru,Lee, Ji-Yoon,Choi, Yong Jae,Yu, Young Hyun,Moon, Kyung-Sub,Kim, Kyung Keun,Ha, Hyung-Ho,Kim, Sang Elsevier 2019 Phytomedicine Vol.56 No.-

<P><B>Abstract</B></P> <P><B>Background</B></P> <P>Lichens, which represent symbiotic associations of fungi and algae, are potential sources of numerous natural products. Physciosporin (PHY) is a potent secondary metabolite found in lichens and was recently reported to inhibit the motility of lung cancer cells via novel mechanisms.</P> <P><B>Purpose</B></P> <P>The present study investigated the anticancer potential of PHY on colorectal cancer (CRC) cells.</P> <P><B>Methods</B></P> <P>PHY was isolated from lichen extract by preparative TLC. The effect of PHY on cell viability, motility and tumourigenicity was elucidated by MTT assay, hoechst staining, flow cytometric analysis, transwell invasion and migration assay, soft agar colony formation assay, Western blotting, qRT-PCR and PCR array <I>in vitro</I> as well as tumorigenicity study <I>in vivo</I>.</P> <P><B>Results</B></P> <P>PHY decreased the viability of various CRC cell lines (Caco2, CT26, DLD1, HCT116 and SW620). Moreover, PHY elicited cytotoxic effects by inducing apoptosis at toxic concentrations. At non-toxic concentrations, PHY dose-dependently suppressed the invasion, migration and colony formation of CRC cells. PHY inhibited the motility of CRC cells by suppressing epithelial-mesenchymal transition and downregulating actin-based motility markers. In addition, PHY downregulated β-catenin and its downstream target genes cyclin-D1 and c-Myc. Moreover, PHY modulated KAI1 C-terminal-interacting tetraspanin and KAI1 expression, and downregulated the downstream transcription factors c-jun and c-fos. Finally, PHY administration showed considerable bioavailability and effectively decreased the growth of CRC xenografts in mice without causing toxicity.</P> <P><B>Conclusion</B></P> <P>PHY suppresses the growth and motility of CRC cells via novel mechanisms.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Tetranitrophthalocyanine Zinc/TiO2 Nanofibers Organic–Inorganic Heterostructures with Enhanced Visible Photocatalytic Activity

Q. Zhang,S. Zhou,S. F. Fu,X. Z. Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.10

"2,9,16,23-tetranitrophthalocyanine zinc (TNZnPc)/TiO2 organic–inorganic heterostructures were successfully fabricated by a simple combination method of electrospinning technique and solvothermal processing. These photocatalysts were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV–Vis, energy dispersive X-ray and X-ray photoelectron spectroscopy. The photocatalytic studies revealed that the TNZnPc/TiO2 organic–inorganic heterostructures exhibited enhanced photocatalytic efficiency of photo-degradation of rhodamine B compared with pure TiO2 nanofibers under visible-light irradiation. Further studies indicate that the photosynergistic effect of organic–inorganic heterostructures can remarkably enhance the photoinduced interfacial charge transfer, thereby increasing the charge separation during the photocatalytic reaction."

MHD Instability Fluctuation Measurement on the HL-2A Tokamak by Using the HCN Laser Interferometer

Y. G. Li,Y. Zhou,Z. C. Deng,J. Yi,Y. Li,H. X. Wang,X. Q. Ji,W. Deng 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.8

The multichannel HCN laser interferometer has been routinely used to measure the electron density(ne) on the HL-2A tokamak for several years. In order to explore its capability for qualitativelyevaluating the Magnetohydrodynamic (MHD) fluctuation in plasmas from the probing signal, weimplemented two important modifications on the hardware of channel #3 (r = −10.5 cm): (1) applicationof the high-response Schottky diode waveguide detector, and (2) utilization of a preamplifierwith a broad pass-band of up to 500 kHz so as not to filter the fluctuation component mixed withthe intermediate frequency (IF). Many MHD fluctuation phenomena, such as tearing modes (TMs),fishbones, long lived modes (LLMs), have been successfully detected by using the modified channel#3 in the HL-2A experimental campaign, and the results were quite coincident with those derivedfrom the magnetic probe and the soft X-ray systems. We propose to apply this novel approach tomore channels of the HCN laser interferometer.

Densification, microstructure and hardness of Sm2Zr2O7/SmAlO3 ceramic composites

Z.-G. Liu,R.-X. Zhu,J.H. Ouyang,Y. Zhou 한양대학교 세라믹연구소 2015 Journal of Ceramic Processing Research Vol.16 No.4

The densification behaviour of Sm2Zr2O7/SmAlO3 ceramic composites was studied by pressureless sintering at temperatures of 1500-1700 ℃ for 10 h in air. The microstructure and hardness of Sm2Zr2O7/SmAlO3 ceramic composites were investigated by the X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Vickers hardness tester. The Sm2Zr2O7/SmAlO3 ceramic composites are composed of pyrochlore-type Sm2Zr2O7 and perovskite-like SmAlO3 structure. The relative density of Sm2Zr2O7/SmAlO3 ceramic composites increases with increasing sintering temperature. Vickers hardness of Sm2Zr2O7/SmAlO3 ceramic composites slightly increases with increasing SmAlO3 content.

Whole Earth Telescope observations of the subdwarf B star KPD 1930+2752: a rich, short‐period pulsator in a close binary

Reed, M. D.,Harms, S. L.,Poindexter, S.,Zhou, A.&#x2010,Y.,Eggen, J. R.,Morris, M. A.,Quint, A. C.,McDaniel, S.,Baran, A.,Dolez, N.,Kawaler, S. D.,Kurtz, D. W.,Moskalik, P.,Riddle, R.,Zola, S.,Østense Blackwell Publishing Ltd 2011 Monthly notices of the Royal Astronomical Society Vol.412 No.1

<P><B>ABSTRACT</B></P><P>KPD 1930+2752 is a short‐period pulsating subdwarf B (sdB) star. It is also an ellipsoidal variable with a known binary period of 2.3 h. The companion is most likely a white dwarf and the total mass of the system is close to the Chandresekhar limit. In this paper, we report the results of Whole Earth Telescope (WET) photometric observations during 2003 and a smaller multisite campaign of 2002. From 355 h of WET data, we detect 68 pulsation frequencies and suggest an additional 13 frequencies within a crowded and complex temporal spectrum between 3065 and 6343 μHz (periods between 326 and 157 s). We examine pulsation properties including phase and amplitude stability in an attempt to understand the nature of the pulsation mechanism. We examine a stochastic mechanism by comparing amplitude variations with simulated stochastic data. We also use the binary nature of KPD 1930+2752 for identifying pulsation modes via multiplet structure and a tidally induced pulsation geometry. Our results indicate a complicated pulsation structure that includes short‐period (≈16 h) amplitude variability, rotationally split modes, tidally induced modes and some pulsations which are geometrically limited on the sdB star.</P>

Alluaudite Na₂Co₂Fe(PO₄)₃ as an electroactive material for sodium ion batteries

Essehli, R.,Belharouak, I.,Ben Yahia, H.,Maher, K.,Abouimrane, A.,Orayech, B.,Calder, S.,Zhou, X. L.,Zhou, Z.,Sun, Y-K. The Royal Society of Chemistry 2015 Dalton Transactions Vol.44 No.17

<P>The electroactive orthophosphate Na<SUB>2</SUB>Co<SUB>2</SUB>Fe(PO<SUB>4</SUB>)<SUB>3</SUB> was synthesized using a solid state reaction. Its crystal structure was solved using the combination of powder X-ray- and neutron-diffraction data. This material crystallizes according to the alluaudite structure (S.G. <I>C</I>2/<I>c</I>). The structure consists of edge sharing [MO<SUB>6</SUB>] octahedra (M = Fe, Co) resulting in chains parallel to [−101]. These chains are linked together <I>via</I> the [PO<SUB>4</SUB>] tetrahedra to form two distinct tunnels in which sodium cations are located. The electrochemical properties of Na<SUB>2</SUB>Co<SUB>2</SUB>Fe(PO<SUB>4</SUB>)<SUB>3</SUB> were evaluated by galvanostatic charge–discharge cycling. During the first discharge to 0.03 V, Na<SUB>2</SUB>Co<SUB>2</SUB>Fe(PO<SUB>4</SUB>)<SUB>3</SUB> delivers a specific capacity of 604 mA h g<SUP>−1</SUP>. This capacity is equivalent to the reaction of more than seven sodium ions per formula unit. Hence, this is a strong indication of a conversion-type reaction with the formation of metallic Fe and Co. The subsequent charge and discharge involved the reaction of fewer Na ions as expected for a conversion reaction. When discharged to 0.9 V, the material intercalated only one Na<SUP>+</SUP>-ion leading to the formation of a new phase Na<SUB>3</SUB>Co<SUB>2</SUB>Fe(PO<SUB>4</SUB>)<SUB>3</SUB>. This phase could then be cycled reversibly with an average voltage of 3.6 V <I>vs.</I> Na<SUP>+</SUP>/Na and a capacity of 110 mA h g<SUP>−1</SUP>. This result is in good agreement with the theoretical capacity expected from the extraction/insertion of two sodium atoms in Na<SUB>3</SUB>Co<SUB>2</SUB>Fe(PO<SUB>4</SUB>)<SUB>3</SUB>.</P> <P>Graphic Abstract</P><P>Na<SUB>2</SUB>Co<SUB>2</SUB>Fe(PO<SUB>4</SUB>)<SUB>3</SUB> crystallizes with the alluaudite-type structure (S.G. <I>C</I>2/<I>c</I>) and plays a dual anode/cathode behavior in sodium ion batteries. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5dt00971e'> </P>