First-principles calculations of the effect of Ge content on the electronic, mechanical and acoustic properties of Li17Si4-xGex

Xiaohong Li,Hong-Ling Cui,Rui-Zhou Zhang 한국물리학회 2019 Current Applied Physics Vol.19 No.6

The electronic, mechanical and acoustic properties of Li17Si4-xGex (x=0, 2.3, 3.08, 3.53, and 4) have been investigated by using first-principles calculations based on the density functional theory (DFT). The research shows that the bulk modulus B, Young's modulus E, shear modulus G, and hardness Hv gradually decrease with the increasing Ge content. Li17Si4-xGex have the brittle nature from the analysis of B/G ratio and Cauchy pressure. The maximum Young's moduli are all along [1 1 0] plane, and the sequence of degree of anisotropic property is Li17Ge4 > Li17Si0.48Ge3.52 > Li17Si0.92Ge3.08 > Li17Si1.7Ge2.3 > Li17Si4. The analysis of acoustic velocity shows that all the sound velocities decrease with the increasing Ge content for Li17Si4-xGex (x=0, 2.3, 3.08, 3.53, and 4), and the longitudinal wave along [111] direction is fastest for the studied compounds. Debye temperature ΘD, vt and vl decrease with the increasing Ge content. The minimum thermal conductivity decreases with the increasing Ge content, and Li17Si4-xGex have low thermal conductivities and are not potential thermal conductors. The analysis of electronic properties indicates that Li17Si4-xGex have the metal nature and anisotropic electrical conductivity. The electric conduction is improved with the increasing Ge content.

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>

Synthesis and Solution Properties of Zwitterionic Copolymer of Acrylamide with 3-[(2-Acrylamido)dimethylammonio]propanesulfonate

Hui Xiao,Jing Hu,Shuailin Jin,Rui Hai Li 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.9

A novel zwitterionic monomer 3-[(2-acrylamido)dimethylammonio]propanesulfonate (DMADAS) was designed and synthesized in this study. Then it was polymerized with acrylamide (AM) by free radical polymerization in 0.5 mol/L NaCl solution with ammonium persulfate ((NH4)2S2O8) and sodium sulfate (NaHSO3) as initiator. The structure and composition of DMADAS and acrylamide-3-[(2-acrylamido)- dimethylammonio]propanesulfonate copolymer (P-AM-DMADAS) were characterized by FT-IR spectroscopy, 1H NMR and elemental analyses. Isoelectric point (IEP) of P-AM-DMADAS was tested by nanoparticle size and potential analyzer. Solution properties of copolymer were studied by reduced viscosity. Antipolyelectrolyte behavior was observed and was found to be enhanced with increasing DMADAS content in copolymer. The results showed that the viscosity of P-AM-DMADAS is 5.472 dl/g in pure water. Electrolyte was added, which weakened the mutual attraction between sulfonic acid group and quaternary ammonium group. The conformation became loose, which led to the increase of reduced viscosity. The ability of monovalent and divalent cation influencing the viscosity of zwitterionic copolymer obeyed the following sequence: Li+ < Na+ < K+, Mg2+ < Ca2+ < Ba2+, and that of anion is in the order: Cl− < Br− < I−, CO3 2− > SO3 2− ≈ SO4 2−.

In-situ photocrosslinked hydroxide conductive membranes based on photosensitive poly(arylene ether sulfone) block copolymers for anion exchange membrane fuel cells

He, Rui,Wen, Pushan,Zhang, Hai-Ning,Guan, Shumeng,Xie, Guangyong,Li, Li-Zhong,Lee, Myong-Hoon,Li, Xiang-Dan Elsevier 2018 Journal of membrane science Vol.556 No.-

<P><B>Abstract</B></P> <P>A series of photocrosslinkable multi-block poly(arylene ether sulfone) copolymers containing various block lengths of hydrophilic segments were synthesized. For comparison, a series of random poly(arylene ether) copolymers were also synthesized. The anion exchange membranes(AEMs) were fabricated and in-situ photocrosslinking was carried out by UV irradiation in a swollen state. The microphase-separated morphologies of the multi-block membranes were characterized by SAXS and TEM experiments, and the membrane properties were investigated by measuring ion exchange capacity (IEC), water uptake, water swelling ratio, ionic conductivity, methanol permeability and alkaline stability. IECs and water uptakes of the crosslinked multi-block membranes were in the range of 1.11–1.42 meq g<SUP>−1</SUP> and 14.36–31.01% at 20 °C, respectively. The hydroxide conductivity was in the range of 11.38–25.00 mS cm<SUP>−1</SUP> at 20 °C, and showed a maximum value of 178.77 mS cm<SUP>−1</SUP> at 100 °C. The multi-block membranes exhibited low methanol permeability (2.75 × 10<SUP>−7</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>) at room temperature, which is one order of magnitude lower than that of Nafion® 117 (23.8 × 10<SUP>−7</SUP> cm<SUP>2</SUP> s<SUP>−1</SUP>). The crosslinked membranes showed excellent dimensional stability and alkaline stability with only a slight decrease in ionic conductivity. All the multi-block membranes showed superior properties compared to their corresponding random copolymers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Multi-block poly(arylene ether sulfone) copolymers were synthesized for AEMs. </LI> <LI> <I>In-situ</I> photo-crosslinking was carried out by UV irradiation in hydrated states. </LI> <LI> The block copolymers exhibited hydrophilic/hydrophobic phase separated morphology. </LI> <LI> The block copolymers showed superior properties compare to the random copolymers. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Alantolactone selectively suppresses STAT3 activation and exhibits potent anticancer activity in MDA-MB-231 cells

Chun, Jaemoo,Li, Rui-Juan,Cheng, Mao-Sheng,Kim, Yeong Shik Elsevier 2015 Cancer letters Vol.357 No.1

<P><B>Abstract</B></P> <P>The important goal of cancer drug discovery is to develop therapeutic agents that are effective, safe, and affordable. In the present study, we demonstrated that alantolactone, which is a sesquiterpene lactone, has potential activity against triple-negative breast cancer MDA-MB-231 cells by suppressing the signal transducer and activator of transcription 3 (STAT3) signaling pathway. Alantolactone effectively suppressed both constitutive and inducible STAT3 activation at tyrosine 705. Alantolactone decreased STAT3 translocation to the nucleus, its DNA-binding, and STAT3 target gene expression. Alantolactone significantly inhibits STAT3 activation with a marginal effect on MAPKs and on NF-κB transcription; however, this effect is not mediated by inhibiting STAT3 upstream kinases. Although SHP-1, SHP-2, and PTEN, which are protein tyrosine phosphatases (PTPs), were not affected by alantolactone, the treatment with a PTP inhibitor reversed the alantolactone-induced suppression of STAT3 activation, indicating that PTP plays an important role in the action of alantolactone. Finally, alantolactone treatment resulted in the inhibition of migration, invasion, adhesion, and colony formation. The <I>in vivo</I> administration of alantolactone inhibited the growth of human breast xenograft tumors. These results provide preclinical evidence to continue the development of alantolactone as a STAT3 inhibitor and as a potential therapeutic agent against breast cancer.</P> <P><B>Highlights</B></P> <P> <UL> <LI> STAT3 is a transcription factor that is a potent regulator of tumorigenesis. </LI> <LI> Alantolactone suppresses constitutive and inducible STAT3 tyrosine phosphorylation. </LI> <LI> Alantolactone inhibits NF-κB translocation to the nucleus. </LI> <LI> Alantolactone inhibits cell migration, invasion, adhesion, and colony formation. </LI> <LI> Alantolactone inhibits the tumor growth of MDA-MB-231 xenografts in mice. </LI> </UL> </P>

Fabrication of highly efficient coatable polarizer from tolane-based smectic reactive mesogen

He, Rui,Oh, Enche,Ye, Yang,Wen, Pushan,Jeong, Kwang-Un,Lee, Seung Hee,Li, Xiang-Dan,Lee, Myong-Hoon Elsevier 2019 Polymer Vol.176 No.-

<P><B>Abstract</B></P> <P>This work is aimed to fabricate ultra-thin coatable polarizers on a single substrate based on “host-guest” effect between highly ordered smectic reactive mesogen (RM) and dichroic dye. We designed and synthesized a new tolane-based RM with a highly ordered smectic A phase at room temperature. Polymerizable “host-guest” mixture was formulated from the host RM, dichroic dye and additives, then spin-coated on a single substrate having an alignment layer. Subsequent in-situ photopolymerization by UV irradiation successfully resulted in a coatable polarizer with good polarizing properties. The fabricated coatable polarizer showed a dichroic ratio (DR) of 16.4 and a degree of polarization (DOP) of 99.3% with the thickness of 4 μm. The resulting coatable polarizer possessed a considerable solvent resistance, good thermal stability and robust mechanical properties. Moreover, we prepared a TN-mode LC cell by using the prepared coatable polarizers inside the cell (in-cell), in which the coatable polarizers acted as a polarizer and an alignment layer, simultaneously. The resulting TN cell with in-cell polarizers exhibited a decent electro-optical behavior. We believe that the coatable polarizer proposed in this study possesses practical application potential in ultra-thin LCDs or flexible OLEDs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Reactive mesogen with smectic A phase was synthesized for coatable polarizer. </LI> <LI> Coatable polarizer was fabricated on a single substrate by “host-guest” method. </LI> <LI> Coatable polarizer exhibits considerable optical property and excellent stability. </LI> <LI> LCD with in-cell structure was demonstrated by using the prepared coatable polarizer. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Syntheses and characterizations of high refractive index and low birefringence polyimides containing spirobifluorene in the side chain

Wen, Pushan,He, Rui,Li, Xiang-Dan,Lee, Myong-Hoon Elsevier 2017 Polymer Vol.117 No.-

<P><B>Abstract</B></P> <P>Two new diamine monomers having a spirobifluorene structure were synthesized through four steps, and polymerized with three different dianhydrides (PMDA, CBDA and 6FDA) to obtain six polyimides with spirobifluorene structure in the side chain. All the resulting polyimides displayed excellent thermal stability and high glass transition temperature. These polyimides synthesized from CBDA and 6FDA showed good solubility in typical organic solvents such as NMP, DMF and DMSO. Transparent and flexible cast films can be obtained from soluble polyimides or poly(amic acid) solution. The transmittance of polyimide films was higher than 90% in the visible wavelength range (higher than 80% in case of polyimide containing PMDA). The refractive indices of the result polyimides were found to be in the range from 1.6343 to 1.7007, which is higher than that of normal polymers. In addition, the optical birefringences of these polyimides were extremely low (0.0005–0.0014). The high refractive index and low birefringence of these polyimides as well as other descent physical and thermal properties would offer them possible applications in high performance optical materials such as flexible substrates.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel polyimides containing 9,9’-spirobifluorene unit in the side chain were synthesized. </LI> <LI> The polyimides exhibit high thermal stability (T5 > 420 °C) with excellent optical properties such as high transparency (>90% at 400 nm), high refractive index (1.6342–1.7007) and low birefringence (0.0005–0.0014). </LI> <LI> The resulting polymer materials could be promising candidates for advanced optical applications. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Novel polyimides containing 9,9′-spirobifluorene unit in the side chain, which exhibit high transparency, high refractive index and low birefringence, have been developed as promising candidates for advanced optical applications.</P> <P>[DISPLAY OMISSION]</P>

Quality improvement effects of electrolyzed water on rice noodles prepared with semidry-milled rice flours

Rui Liu,Zhang-Long Yu,Yuan-Lin Sun,Li-Tao Tong,Li-Ya Liu,Li-Li Wang,Xian-Rong Zhou,Su-Mei Zhou 한국식품과학회 2021 Food Science and Biotechnology Vol.30 No.6

To investigate the effects of electrolyzed watertreatment on the qualities of rice noodles prepared withsemidry- milled rice flour, pasting properties and thermalproperties of rice flour, and the cooking and texturalproperties of rice noodles were determined. Higher peakviscosity and lower melting enthalpy were observed inelectrolyzed water (EW) treated rice flour. The hardness,gumminess and chewiness of rice noodle in slightly acidicelectrolyzed water treated rice noodles with availablechlorine concentration (ACC) 20.32 mg/L were increasedsignificantly (p\0.05). The cooking loss decreased significantlyin strong acidic electrolyzed water treated noodleswith ACC 10.09 mg/L treatment (p\0.05). Theresults indicated that EW could promote the gelatinizationof rice flour, and improve the textural qualities of ricenoodles. Therefore EW was appropriate to be used in ricenoodle production.

Designing a Magnetically Controlled Soft Gripper with Versatile Grasping Based on Magneto-Active Elastomer

Rui Li,Xinyan Li,Hao Wang,Xianlun Tang,Penghua Li,Mengjie Shou 한국정보처리학회 2022 Journal of information processing systems Vol.18 No.5

A composite bionic soft gripper integrated with electromagnets and magneto-active elastomers is designed bycombining the structure of the human hand and the snake’s behavior of enhancing friction by actively adjustingthe scales. A silicon-based polymer containing magnetized hard magnetic particles is proposed as a soft finger,and it can be reversibly bent by adjusting the magnetic field. Experiments show that the length, width, andheight of rectangular soft fingers and the volume ratio of neodymium–iron–boron have different effects onbending angle. The flexible fingers with 20 vol% are the most efficient, which can bend to 90° when themagnetic field is 22 mT. The flexible gripper with four fingers can pick up 10.51 g of objects at the magneticfield of 105 mT. In addition, this composite bionic soft gripper has excellent magnetron performance, and itcan change surface like snakes and operate like human hands. This research may help develop soft devices formagnetic field control and try to provide new solutions for soft grasping.

Bond-Slip Behaviors Between BFRP Bar and Ecological High Ductility Concrete Using the Beam Test

Li-Juan Chai,Li-Ping Guo,Bo Chen,Zhu Li,Rui Ma,Kai Li 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.12

To better understand the design parameters of bridge deck link slab made by basalt fiber reinforced polymer (BFRP) bar and ecological high ductility concrete (Eco-HDC), the bond behaviors of BFRP bar embedded in Eco-HDC using beam test based on RILEM standard were studied. The beam specimens had variable factors namely diameter of BFRP bar, embedment length and cover thickness. The results indicate that most beam specimens display a failure mode of BFRP bar pulled out with specimen splitting. Besides, with the increase of diameter and embedment length, the bond strength decreases. While as the cover thickness increases, the bond strength and first bond stress show an increasing trend. The free end slip increases as the embedment length or cover thickness increases. In addition, the strain at loaded end is larger than that at free end as the load increases. Moreover, the formulas of bond strength and peak slip are proposed based on the test data of specimens. At last, embedment length and cover thickness of BFRP bar in the bridge deck link slab are recommended.