Recent Developments in the Effects of Different Dopants on the Structure and Property of Lithium Titanate Material

Xi-Yang Li,Qian-Lin Chen,Min Yang,Ya-Nan Li,Jing-Bo Ma 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3

The lithium titanium spinel Li4Ti5O12 has attracted more and more attention as anode materials applied in lithium ion batteries. Li4Ti5O12 material has been found to be able to intercalate lithium ions without deformation of the lattice. However, compared with graphite and other anode materials, the low conductivity of Li4Ti5O12 restricts its charging and discharging rate. Doping is deemed to be a businesslike method to enhance ionic and electronic conductivity of Li4Ti5O12. This paper reviews the effects of Li4Ti5O12 with different doping ions on different crystal lattice states. And it has been found by a summary that the doping objective of doping ions at Li4Ti5O12 is also different. Moreover, the applications of ion doping in different fields of Li4Ti5O12 are prospected.

Critical Descriptor for the Rational Design of Oxide-Based Catalysts in Rechargeable Li–O₂ Batteries: Surface Oxygen Density

Zheng, Yongping,Song, Kyeongse,Jung, Jaepyeong,Li, Chenzhe,Heo, Yoon-Uk,Park, Min-Sik,Cho, Maenghyo,Kang, Yong-Mook,Cho, Kyeongjae American Chemical Society 2015 Chemistry of materials Vol.27 No.9

<P>Li-O-2 batteries provide high-capacity energy storage, but for aprotic Li-O-2 batteries, it is reported that the charge-discharge efficiency is ultimately limited by the crystal growth of insoluble Li2O2 on the porous cathode. Catalysts have been reported to improve the nucleation and morphology of Li2O2, which helps achieve high energy densities. We provide a new insight into the catalytic mechanism of the oxygen reduction reaction (ORR) in aprotic Li-O-2 batteries the oxygen sites on the surface play a more important role than the exposed metal sites via a study based on the density functional theory (DFT) examining alpha-MnO2 surfaces. Lithium ions from electrolytes are found to interact with the surface oxygen sites and form surface lithium sites, facilitating further growth of Li2O2. A larger number of initial growth points with uniform distribution makes Li2O2 well dispersed, forming small particles, which benefit both the ORR and oxygen evolution reactions (OER). This design concept for oxygen sites has been successfully validated by the real Li-O-2 cell experiments with alpha-MnO2 nanowire cathodes.</P>

RESULTS ON THE ALGEBRAIC DIFFERENTIAL INDEPENDENCE OF THE RIEMANN ZETA FUNCTION AND THE EULER GAMMA FUNCTION

Xiao-Min Li,Yi-Xuan Li 대한수학회 2023 대한수학회보 Vol.60 No.6

In 2010, Li-Ye \cite[Theorem 0.1]{LiYe2010} proved that \begin{equation}\nonumber P\left(\zeta(z),\zeta'(z),\ldots,\zeta^{(m)}(z),\Gamma(z),\Gamma'(z),\Gamma^{''}(z)\right) \not\equiv 0\quad\text{in }\ \mathbb{C}, \end{equation} where $m$ is a non-negative integer, and $P(u_{0},u_{1}, \ldots, u_{m},v_{0},v_{1},v_{2})$ is any non-trivial polynomial in its arguments with coefficients in the field $\mathbb{C}$. Later on, Li-Ye \cite[Theorem 1]{LiYe2016} proved that \begin{equation}\nonumber P\left(z,\Gamma(z),\Gamma'(z),\ldots,\Gamma^{(n)}(z), \zeta(z)\right)\not\equiv 0 \end{equation} in $z\in \mathbb{C}$ for any non-trivial distinguished polynomial $P(z,u_0, u_1,\ldots$, $u_n, v)$ with coefficients in a set $L_\delta$ of the zero function and a class of non-zero functions $f$ from $\mathbb{C}$ to $\mathbb{C}\cup\{\infty\}$ (cf.~\cite[Definition 1]{LiYe2016}). In this paper, we prove that $P\left(z,\zeta(z),\zeta'(z),\ldots,\zeta^{(m)}(z),\Gamma(z),\Gamma'(z),\ldots,\Gamma^{(n)}(z)\right)\not\equiv 0$ in $z\in\mathbb{C}$, where $m$ and $n$ are two non-negative integers, and $$P(z, u_0,u_1,\ldots,u_m,v_0,v_1,\ldots,v_n)$$ is any non-trivial polynomial in the $m+n+2$ variables $$u_0,u_1,\ldots,u_m,v_0,v_1,\ldots,v_n$$ with coefficients being meromorphic functions of order less than one, and the polynomial $P(z, u_0,u_1,\ldots,u_m,v_0,v_1,\ldots,v_n)$ is a distinguished polynomial in the $n+1$ variables $v_0,v_1,\ldots, v_n$. The question studied in this paper is concerning the conjecture of Markus from \cite{Markus2007}. The main results obtained in this paper also extend the corresponding results from Li-Ye \cite{LiYe2008} and improve the corresponding results from Chen-Wang \cite{Chen2021} and Wang-Li-Liu-Li \cite{Wang2021}, respectively.

A Comparative Experimental Study of the, In-vitro Efficiency of Hypertonic, Saline-Enhanced Hepatic Bipolar and, Monopolar Radiofrequency Ablation

Lee, Jeong Min,Han, Joon Koo,Kim, Se Hyung,Sohn, Kyu Li,Lee, Kyoung Ho,Ah, Su Kyung,Choi, Byung Ihn Korean Radiological Society 2003 Korean Journal of Radiology Vol.4 No.3

Superior lithium/potassium storage capability of nitrogen-rich porous carbon nanosheets derived from petroleum coke

Li, Peng,Hwang, Jang-Yeon,Park, Sang-Min,Sun, Yang-Kook The Royal Society of Chemistry 2018 Journal of Materials Chemistry A Vol.6 No.26

<P>Tremendous attention has been paid to carbon-based anodes for lithium-ion and potassium-ion batteries. Nevertheless, conferring high energy storage properties using carbon-based anodes is still challenging. In this work, petroleum coke-based nitrogen-doped porous carbon nanosheets (N-PCSs) were prepared using carbon nitride (g-C3N4) as both a template and nitrogen source and tested as advanced anode materials. The as-obtained N-PCSs constructed through an <I>in situ</I> solid-state approach possess both high capacity and excellent cycling stability. High capacities were obtained for Li-ion and K-ion batteries (407 mA h g<SUP>−1</SUP> after 500 cycles at 3720 mA g<SUP>−1</SUP> and 206 mA h g<SUP>−1</SUP> after 300 cycles at 1000 mA g<SUP>−1</SUP>, respectively); these are some of the best capacities for carbon-based electrode materials and could be ascribed to the unique microstructure of the anodes, <I>i.e.</I>, nanosheet morphology, developed porosity, ultrahigh nitrogen doping, and a high level of disorder. Meanwhile, this study represents a milestone for high-value utilization of petroleum coke and other kinds of heavy oil.</P>

Optimized Assembly of Micro-/Meso-/Macroporous Carbon for Li–S Batteries

Qiong Tang,Heqin Li,Min Zuo,Jing Zhang,Yiqin Huang,Peiwen Bai,Jiaqi Xu,Kuan Zhou 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.2

In order to explore the effect of hierarchical porous carbon on the performances of Li–S batteries, we synthesized three kinds of micro-/meso-/macroporous carbon materials with different pore properties by facile hard-template method. Different from the majority of reports on porous carbon ensuing large specific surface area (SSA) and total pore volume, it was found that in the case of identically high sulfur content, the pore size distribution substantially influences the performances of Li–S batteries rather than the SSA and total pore volume. Furthermore, in the assembly of micro-/meso-/macropores, the micropore volume ratio to the total pore volume is dominant to the capabilities of batteries. Among the samples, the porous carbon carbonized with the precursor of sucrose at 950℃ presents the highest initial discharge specific capacity of 1327 mAh/g and retention of 630 mAh/g over 100 cycles at 0.2C rate along with the best rate capability. This sample possesses the largest micropore volume ratio of 47.54% but a medium SSA of 1217 m2 /g and inferior total pore volume of 0.54 cm3 /g. The abundant micropores effectively improve the conductivity of dispersed sulfur particles, inhibit the loss of sulfur series and enable the cathode to exhibit superior electrochemical performances.

Identification and characterization of heat shock proteins in a parasitic wasp Chouioia cuneae (Hymenoptera: Eulophidae)

Li‐Na Pan,Feng-ZhuWANG,Xin-Yue ZHANG,Yan-Ni ZHAO,Geng-Ping ZHU,Min LI 한국곤충학회 2018 Entomological Research Vol.48 No.3

Heat shock proteins (HSPs) are known to be induced in response to various stress factors. Although HSPs have been studied in a number of insects, not much is known about HSPs in the natural enemies of insects, especially parasitoids. In this study, we identified and characterized five full‐length HSP genes (Cchsp40, Cchsp60, Cchsp70, Cchsp83, and Cchsp90) from an endoparasitic chalcid wasp, Chouioia cunea, which parasitizes the fall webworm, Hyphantria cunea pupae, a worldwide pest. The expression of Cchsps in response to temperature, pesticide stresses and UV radiation were also investigated by quantitative real‐time polymerase chain reaction (RT‐qPCR). The results showed that all five Cchsps were induced in response to hot and cold temperatures. Four pesticides induced the abundant expression of Cchsp70, Cchsp83 and Cchsp90 while ultraviolet radiation up‐regulated Cchsp40, Cchsp70, Cchsp83 and Cchsp90. These results indicate the different transcriptional profiles of the five different Cchsps in response to various abiotic stresses. The findings of this study provide insights into the response of C. cunea to abiotic stresses and insight into the use of this parasitoid in biological control strategies.

Low-Temperature Carbon Coating of Nanosized Li_1.015Al_0.06Mn_1.925O₄ and High-Density Electrode for High-Power Li-Ion Batteries

Lee, Min-Joon,Lho, Eunsol,Bai, Peng,Chae, Sujong,Li, Ju,Cho, Jaephil American Chemical Society 2017 NANO LETTERS Vol.17 No.6

<P>Despite their good intrinsic rate capability, nanosized spinel cathode materials cannot fulfill the requirement of high electrode density and volumetric energy density. Standard carbon coating cannot be applied on spinel materials due to the formation of oxygen defects during the high-temperature annealing process. To overcome these problems, here we present a composite material consisting of agglomerated nanosized primary particles and well-dispersed acid treated Super P carbon black powders, processed below 300 degrees C. In this structure, primary particles provide fast lithium ion diffusion in solid state due to nanosized diffusion distance. Furthermore, uniformly dispersed acid-treated Super P (ASP) in secondary particle facilitates lower charge transfer resistance and better percolation of electron. The ASPLMO material shows superior rate capability, delivering 101 mAh g 1 at 300 degrees C-rate at 24 degrees C, and 75 mAh g(-1) at 100 degrees C-rate at 10 degrees C. Even after 5000 cycles, 86 mAh ClIcan be achieved at 30 degrees C=rate at 24 degrees C, demonstrating very competitive full-cell performance.</P>

High-performance Liquid Chromatographic Analysis for Quantitation of Marker Compounds of Artemisia capillaris Thunb.

Kyung Min Park,손종근,Ying Li,Bora Kim,Haiyan Zhang,Kyong Hwangbo,Dong Gen Piao,Mei Juan Chi,우미희,최재수,이제현,문동철,장현욱,김재룡 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.12

Two stable high-performance liquid chromatography (HPLC) methods were developed that could quantitatively analyze 10 major marker compounds of Artemisia capillaris Thunb and could also distinguish among ‘Injinho’ and ‘Myeon-injin’ and ‘Haninjin’ – A. capillaris collected in autumn,A. capillaris collected in spring and A. iwayomogi, which can be misused as ‘Injinho’ in Korean herbal drug markets. The first HPLC method was a reversed-phase chromatography using a C18 column with an isocratic solvent system of phosphoric acid (0.05%) and acetonitrile at the flow rate of 1.0 mL/min, ultraviolet (UV) detection wavelength at 254 nm and column temperature at 40oC. Calibration and quantitation were made by using acetaminophen as an internal standard (I.S-A) and chlorogenic acid (1) was determined within 20 min. The second HPLC method was a reversed-phase chromatography using a C18 column with a gradient solvent system of phosphate buffer (0.015 M, pH 6) and acetonitrile at the flow rate of 1.0 mL/min, UV detection wavelength at 254 nm and column temperature at 40oC. Calibration and quantitation were made by using ethylparaben as an internal standard (I.S-B) and 3,5-di-O-caffeoylquinic acid (2), 3,4-di-O-caffeoylquinic acid (3), 4,5-di-O-caffeoylquinic acid (4), hyperoside (5), isoquercitrin (6), isorhamnetin 3-O-robinobioside (7), isorhamnetin-3-O-galactoside (8), isorhamnetin-3-O-glucoside (9) and scoparone (10) were determined within 60 min. Pattern recognition analysis of data from the 60 samples classified them clearly into three groups. These assay methods could be applied for QA/QC of A. capillaris and Artemisia iwayomogi.

FSCB phosphorylation in mouse spermatozoa capacitation

( Shun Li Liu ),( Bing Ni ),( Xiang Wei Wang ),( Wen Qian Huo ),( Jun Zhang ),( Zhi Qiang Tian ),( Ze Min Huang ),( Yi Tian ),( Jun Tang ),( Yan Hua Zheng ),( Feng Shuo Jin ),( Yan Feng Li ) 생화학분자생물학회(구 한국생화학분자생물학회) 2011 BMB Reports Vol.44 No.8

It is generally accepted that spermatozoa capacitation is associated with protein kinase A-mediated tyrosine phosphorylation. In our previous study, we identified the fibrous sheath CABYR binding protein (FSCB), which was phosphorylated by PKA. However, the phosphorylation status of FSCB protein during spermatozoa capacitation should be further investigated. To this aim, in this study, we found that phosphorylation of this 270-kDa protein occurred as early as 1 min after mouse spermatozoa capacitation, which increased over time and remained stable after 60 min. Immunoprecipitation assays demonstrated that the tyrosine and Ser/Thr phosphorylation of FSCB occurred during spermatozoa capacitation. The extent of phosphorylation and was closely associated with the PKA activity and spermatozoa motility characteristics. FSCB phosphorylation could be induced by PKA agonist DB-cAMP, but was blocked by PKA antagonist H-89.Therefore, FSCB contributes to spermatozoa capacitation in a tyrosine-phosphorylated format, which may help in further elucidating the molecular mechanism of spermatozoa capacitation. [BMB reports 2011; 44(8): 541-546]