Synthesis of full concentration gradient cathode studied by high energy X-ray diffraction

Li, Yan,Xu, Rui,Ren, Yang,Lu, Jun,Wu, Huiming,Wang, Lifen,Miller, Dean J.,Sun, Yang-Kook,Amine, Khalil,Chen, Zonghai Elsevier 2016 Nano energy Vol.19 No.-

<P><B>Abstract</B></P> <P>Nickel-rich metal oxides have been widely pursued as promising cathode materials for high energy-density lithium-ion batteries. Nickel-rich lithium transition metal oxides can deliver a high specific capacity during cycling, but can react with non-aqueous electrolytes. In this work, we have employed a full concentration gradient (FCG) design to provide a nickel-rich core to deliver high capacity and a manganese-rich outer layer to provide enhanced stability and cycle life. <I>In situ</I> high-energy X-ray diffraction was utilized to study the structural evolution of oxides during the solid-state synthesis of FCG lithium transition metal oxide with a nominal composition of LiNi<SUB>0.6</SUB>Mn<SUB>0.2</SUB>Co<SUB>0.2</SUB>O<SUB>2</SUB>. We found that both the pre-heating step and the sintering temperature were critical in controlling phase separation of the transition metal oxides and minimizing the content of Li<SUB>2</SUB>CO<SUB>3</SUB> and NiO, both of which deteriorate the electrochemical performance of the final material. The insights revealed in this work can also be utilized for the design of other nickel-rich high energy-density cathode materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Solid-state synthesis of FCG cathode is investigated by <I>in situ</I> XRD. </LI> <LI> Covariance analysis and Rietveld refinement are used to analyze the HEXRD data. </LI> <LI> Synthetic optimization of FCG cathode with excellent electrochemical performance. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Benefit from the covariance analysis and Rietveld refinement of <I>in situ</I> HEXRD data during the solid state synthesis, we can optimized the solid state synthesis conditions in a short time. And the full concentration gradient cathode composites (nickel-rich core and manganese-rich outer layer) with excellent electrochemical performance are obtained.</P> <P>[DISPLAY OMISSION]</P>

Preparation of lithium-doped NaV6O15 thin film cathodes with high cycling performance in SIBs

Xu Hai-Yan,Ruan Jun Hai,Liu Fang Lin,Li Dong-Cai,Zhang Feng-Jun,Wang Ai-Guo,Sun Dao-Sheng,오원춘 한국세라믹학회 2022 한국세라믹학회지 Vol.59 No.3

Lithium ions-doped NaV6O15 thin films have been prepared using a simple low temperature liquid phase deposition method and subsequent annealing process. X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), scanning elec- tron microscopy (SEM), and photoelectron spectroscopy (XPS) have been used to study the structural and physicochemical characteristics of the NaV6O15 film. The films were grown on the FTO conductive glass and used directly as an electrode of sodium ion batteries. The prepared lithium ions-doped NaV6O15 thin film electrodes showed an excellent cycling stability and discharge capacity, which may be attributed to the stability of the Li+ embedded into the gap between the V–O layers to maintain the structure and its stable β-phase structure transformed after the first cycle. The cycling stability greatly improved with increasing annealing temperature, while the discharge capacity decreased. The capacities of the film electrodes annealed at 400 °C and 450 °C maintained above 97% after 100 cycles. The lithium-doped NaV6O15 underwent a phase transition dur- ing the first charge/discharge cycle. The new transformed phase has perfect crystal structure stability undergoing insertion and deinsertion of Na+. Therefore, the lithium-doped NaV6O15 thin film possesses good cycling stability and is expected to be a promising thin film cathode for sodium-ion batteries.

Inhibition of Microcystis aeruginosa by the Extracellular Substances from an Aeromonas sp

( Yu Mei Liu ),( Ming Jun Chen ),( Meng Hui Wang1 ),( Rui Bao Jia ),( Li Li ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.9

Growth of Microcystis aeruginosa could be inhibited significantly within 24 h by the extracellular substances prepared from Aeromonas sp. strain FM. During the treatment, the concentration of extracellular soluble carbohydrates increased significantly in algal culture. Morphological and ultrastructural changes in M. aeruginosa cells, including breakage of the cell surface, secretion of mucilage, and intracellular disorganization of thylakoids, were observed. HPLC-MS analysis showed that the extracellular substances of Aeromonas sp. strain FM were a mixture of free amino acids, tripeptides, and clavulanate. Among these, the algaelysis effects of lysine and clavulanate were confirmed.

Purification and Characterization of Extracellular Inulinase from a Marine Yeast Pichia guilliermondii and Inulin Hydrolysis by the Purified Inulinase

Fang Gong,Tong Zhang,Jun Sheng,Jing Li,Xianghong Wang,Zhenming Chi 한국생물공학회 2008 Biotechnology and Bioprocess Engineering Vol.13 No.5

The extracellular inulinase of the marine yeast Pichia guilliermondii strain 1 was purified to homogeneity resulting in a 7.2-fold increase in specific inulinase activity. The molecular mass of the purified enzyme was estimated to be 50.0 kDa. The op-timal pH and temperature for the purified enzyme were 6.0 and 60C, respectively. The enzyme was activated by Mn²+, Ca²+, K+, Li+, Na+, Fe³+, Fe²+, Cu²+, and Co²+, but Mg²+, Hg²+, and Ag+ inhibited activity. The enzyme was strongly inhibited by phenylmethanesulphonyl fluoride (PMSF), iodoacetic acid, EDTA, and 1, 10-phenanthroline. The Km and Vmax values of the purified inulinase for inulin were 21.1 mg/mL and 0.08 mg/min, respectively. A large number of monosaccharides were de-tected after the hydrolysis of inulin. The deduced protein sequence from the cloned P. guilliermondii strain 1 inulinase gene contained the consensus motifs R-D-P-K-V-F-W-H and W-M-N-D-P-N-G, which are conserved among the inulinases from other microorganisms.

Hypoglycemic triterpenes from <i>Gynostemma pentaphyllum</i>

Wang, Jun,Ha, Thi Kim Quy,Shi, Yan-Ping,Oh, Won Keun,Yang, Jun-Li Elsevier 2018 Phytochemistry Vol.155 No.-

<P><B>Abstract</B></P> <P>To search for bioactive gypenosides and their analogues, a saponin enriched fraction and its hydrolyzate from <I>Gynostemma pentaphyllum</I> were phytochemically investigated. Fractionation by diverse chromatographic methods, including HPLC, Sephadex LH-20, silica gel, and C18 reverse phase silica gel, led to the isolation and purification of twelve triterpenes, including five undescribed and seven known. The chemical structures of all compounds were determined as analyzed by nuclear magnetic resonance (NMR), high resolution mass spectrometry (HR-MS), infrared spectrum (IR), optical rotation, and chemical transformations. Among all isolates, nine compounds possessed a rare dammarane triterpenoid framework with A-ring modified. The relative configurations of three compounds were determined by 2D NMR for the first time. The absolute configurations of four compounds were determined by the modified Mosher's method. Two of all isolated compounds significantly enhanced 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) uptake and Glucose Transporter 4 (GLUT4) translocation via activating the AMP-activated protein kinase (AMPK) and acetyl-CoA carboxylase (ACC) signaling pathway. This study provided the potential candidates for the development of antidiabetic agents.</P> <P><B>Highlights</B></P> <P> <UL> <LI> <I>Gynostemma pentaphyllum</I> is a traditional medicinal and edible plant in China. </LI> <LI> Five undescribed triterpenes were isolated. </LI> <LI> The modified Mosher's method was used to determine the absolute configurations. </LI> <LI> Their hypoglycemic activity was evaluated in differentiated 3T3-L1 adipocytes. </LI> <LI> This study provided the potential candidates for antidiabetic agents. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Five undescribed and nine known triterpenes were isolated from the hydrolyzate and extract of <I>Gynostemma pentaphyllum.</I> Their hypoglycemic activity was evaluated.</P> <P>[DISPLAY OMISSION]</P>

Biochar-supported nZVI (nZVI/BC) for contaminant removal from soil and water: A critical review

Wang, Shengsen,Zhao, Mingyue,Zhou, Min,Li, Yuncong C.,Wang, Jun,Gao, Bin,Sato, Shinjiro,Feng, Ke,Yin, Weiqin,Igalavithana, Avanthi Deshani,Oleszczuk, Patryk,Wang, Xiaozhi,Ok, Yong Sik Elsevier 2019 Journal of hazardous materials Vol.373 No.-

<P><B>Abstract</B></P> <P>The promising characteristics of nanoscale zero-valent iron (nZVI) have not been fully exploited owing to intrinsic limitations. Carbon-enriched biochar (BC) has been widely used to overcome the limitations of nZVI and improve its reaction with environmental pollutants. This work reviews the preparation of nZVI/BC nanocomposites; the effects of BC as a supporting matrix on the nZVI crystallite size, dispersion, and oxidation and electron transfer capacity; and its interaction mechanisms with contaminants. The literature review suggests that the properties and preparation conditions of BC (e.g., pore structure, functional groups, feedstock composition, and pyrogenic temperature) play important roles in the manipulation of nZVI properties. This review discusses the interactions of nZVI/BC composites with heavy metals, nitrates, and organic compounds in soil and water. Overall, BC contributes to the removal of contaminants because it can attenuate contaminants on the surface of nZVI/BC; it also enhances electron transfer from nZVI to target contaminants owing to its good electrical conductivity and improves the crystallite size and dispersion of nZVI. This review is intended to provide insights into methods of optimizing nZVI/BC synthesis and maximizing the efficiency of nZVI in environmental cleanup.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Aggregation and passivation of nZVI can be alleviated by surfactants and doping methods. </LI> <LI> BC hinders corrosion and improves the dispersion and electron transfer of nZVI. </LI> <LI> Properties of nZVI depend on those of the BC, feedstock and pyrogenic temperature. </LI> <LI> BC enhances electron transfer from nZVI to the contaminants due to the presence of quinone and graphene moieties. </LI> <LI> nZVI/BC shows strong ability to remove HMs, nitrates, and organic contaminants in soil and water. </LI> </UL> </P>

Activation of formyl CH and hydroxyl OH bonds in HMF by the CuO(1 1 1) and Co₃O₄(1 1 0) surfaces: A DFT study

Ren, Jun,Song, Kai-he,Li, Zhenhuan,Wang, Qiang,Li, Jun,Wang, Yingxiong,Li, Debao,Kim, Chan Kyung Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.456 No.-

<P><B>Abstract</B></P> <P>The first principle calculations with on-site Coulomb repulsion U terms were carried out to investigate the 5-hydroxymethylfurfural (HMF) adsorption on the CuO(1 1 1) and Co<SUB>3</SUB>O<SUB>4</SUB>(1 1 0) surfaces, two widely used oxidation catalysts. The adsorption of HMF molecule is energetically favoured in both cases, and HMF is more inclined to bridge adsorption via hydroxyl and formyl groups binding with surface O and metal sites. Moreover, the adsorption energy relies on both the coordination type of surface lattice oxygen to which the H atom binds and the formation of H-bond involving hydroxyl and formyl groups on the adsorbed HMF. Also, the hydroxyl OH bond breaking is very easy and is likely to be the first step in HMF oxidation, and then the OH insertion reaction to produce 2,5-furandicarboxylic acid (FDCA). The corresponding experimental results also show that the CuO and Co<SUB>3</SUB>O<SUB>4</SUB> surfaces are promising candidate catalysts.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CuO(1 1 1) and Co<SUB>3</SUB>O<SUB>4</SUB>(1 1 0) surfaces catalyze the oxidation of 5-hydroxymethylfurfural (HMF). </LI> <LI> Initial binding was formed through bridged-adsorption with O atoms in HMF. </LI> <LI> Oxidation reaction proceeds through the OH bond breaking pathway. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Schematic potential energy diagram for the formyl CH and hydroxyl OH bonds of HMF dissociation on CuO(1 1 1) and Co<SUB>3</SUB>O<SUB>4</SUB>(1 1 0) surfaces. Obviously, the hydroxyl OH bond breaking is easier than that of the formyl CH bond on the two surfaces, which indicates the first step of oxidation of HMF to FDCA should be hydroxyl OH bond breaking.</P> <P>[DISPLAY OMISSION]</P>

High-fidelity bioelectronic muscular actuator based on porous carboxylate bacterial cellulose membrane

Wang, Fan,Jin, Zhen,Zheng, Shaohui,Li, Hao,Cho, Sunghoon,Kim, Hyeon Joe,Kim, Seong-Jun,Choi, Eunpyo,Park, Jong-Oh,Park, Sukho Elsevier 2017 Sensors and actuators. B Chemical Vol.250 No.-

<P><B>Abstract</B></P> <P>Human-friendly electronic products, such as smart mobile phones, soft haptic devices, wearable electronics, and implantable or disposal biomedical devices, will require the use of high-performance durable soft electroactive actuators with eco-friendly, biocompatible, and biodegradable functionalities. Here, we report a high-fidelity bioelectronic muscular actuator based on porous carboxylate bacterial cellulose (CBC) membranes fabricated using the facile zinc oxide (ZnO) particulate leaching (PL) method. The proposed CZ-PL muscular actuator exhibits large deformation, low actuation voltage, fast response, and high-durability in open air environment. In particular, the CZ-PL membrane shows a dramatic increase in the ionic liquid uptake ratio, ionic exchange capacity, and ionic conductivity of up to 70.63%, 22.50%, and 18.2%, respectively, for CBC, resulting in a 5.8 times larger bending deformation than that of the pure CBC actuator. The developed high-performance CZ-PL muscular actuator can be a promising candidate for meeting the tight requirements of human-friendly electronic devices such as wearable devices, biomimetic robots, and biomedical active devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We developed a novel dry-type muscular actuator based on porous carboxylate bacterial cellulose (CBC) membrane. </LI> <LI> The porous CBC membrane was prepared by ZnO particulate leaching method. </LI> <LI> The proposed actuator showed better actuation performance than that of the pure CBC actuator. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Accumulation of Flavonoids and Antioxidant Activity of Stellera chamaejasme by an Efficient Callus Culture

Jun-li Wang,Xuan Xiao,Qian Wang,Xiaoxu Li,Lu Zhang,Jianfei Li 한국원예학회 2013 Horticulture, Environment, and Biotechnology Vol.54 No.5

An efficient callus proliferation system of Stellera chamaejasme was developed. The calli were initially induced by cultivating the leaf explants on the MS medium containing 1.0 mg·L-1 2,4-dichlorophenoxy acetic acid (2,4-D). The culture had its fresh and dry weights increased by about 29 and 25 times, respectively, through further cultivation on the MS medium containing 0.5 mg·L-1 α-naphthalene acetic acid (NAA) and 1.0 mg·L-1 n-phenyl-n′-1,2,3-thiadiazol-5-ylurea (TDZ). The concentrations of NAA and 6-benzylaminopurine (BA) for an efficient accumulation of the total flavonoids in the callus were found to be 1.0 mg·L-1 and 0.25 mg·L-1, respectively. With this combination,the content of the total flavonoids slightly increased to 10.8 mg·g-1 dry weight (DW) in comparison to 10.1 mg·g-1DW obtained in the root of wild-type plant. The antioxidant activities of all flavonoid extracts were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The flavonoid extracts from the callus as induced by 1.0 mg·L-1 NAA and 0.25 or 0.5 mg·L-1 BA was very active in radical scavenging, and their IC50 values were 11.94 and 19.17 μg·mL-1,respectively. Compared to the ascorbic acid (IC50 21.21 μg·mL-1), the antioxidant activity of callus from S. chamaejasme was even stronger, suggesting that be another potential source of new natural antioxidants.

Two-step Holographic Imaging Method based on Single-pixel Compressive Imaging

Jun Li,Yaqing Li,Yuping Wang,Ke Li,Rong Li,Jiaosheng Li,Yangyang Pan 한국광학회 2014 Current Optics and Photonics Vol.18 No.2

We propose an experimental holographic imaging scheme combining compressive sensing (CS) theory with digital holography in phase-shifting conditions. We use the Mach-Zehnder interferometer for hologram formation, and apply the compressive sensing (CS) approach to the holography acquisition process. Through projecting the hologram pattern into a digital micro-mirror device (DMD), finally we will acquire the compressive sensing measurements using a photodiode. After receiving the data of two holograms via conventional communication channel, we reconstruct the original object using certain signal recovery algorithms of CS theory and hologram reconstruction techniques, which demonstrated the feasibility of the proposed method.