Self-adaptive Si/reduced graphene oxide scrolls for high-performance Li-ion battery anodes

Yu, Y.,Li, G.,Zhou, S.,Chen, X.,Lee, H.W.,Yang, W. Pergamon Press ; Elsevier Science Ltd 2017 Carbon Vol.120 No.-

<P>A Si/C composite with Si nanoparticles (nSi) uniformly dispersed in the interlayers of reduced graphene oxide scrolls (rGS) is successfully developed for high-performance Li-ion battery anodes. The rGS can deform reversibly with the repeated expansion/contraction of nSi to maintain contact between the nSi and the conductive rGS network, which can effectively buffer large volume changes and maintain continuous large-area core-shell electrical contact. Additionally, the continuous electrical network of rGS greatly enhances the electrical conductivity, and the open structures at the ends and sides of rGS provide paths for rapid diffusion of Li ions, thus enhancing the rate performance. By virtue of the rational design, the composite shows a high reversible specific capacity of 2030 mA h g(-1) at 0.2 A g(-1), high cycling stability of 1200 mA h g(-1) at 4 A g(-1) with 99.2% capacity retention after 200 cycles, and an excellent rate performance of 1000 mA h g(-1) even at 8 A g(-1). (C) 2017 Elsevier Ltd. All rights reserved.</P>

In-pile tritium release behavior and the post-irradiation experiments of Li4SiO4 fabricated by melting process

Zhao Linjie,Yang Mao,Xiao Chengjian,Gong Yu,Ran Guangming,Chen Xiaojun,Li Jiamao,Yue Lei,Chen Chao,Hou Jingwei,Wang Heyi,Long Xinggui,Peng Shuming 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.1

Understanding the tritium release and retention behavior of candidate tritium breeder materials is crucial for breeder blanket design. Recently, a melt spraying process was developed to prepare Li4SiO4 pebbles, which were subsequently subjected to the in-pile tritium production and extraction platform in China Mianyang Research Reactor (CMRR) to investigate their in-situ tritium release behavior and irradiation performance. The results demonstrate that HT is the main tritium release form, and adding hydrogen to the purge gas reduces tritium retention while increasing the HT percent in the purge gas. Post-irradiation experiments reveal that the irradiated pebbles darken in color and their grains swell, but the mechanical properties remain largely unchanged. It is concluded that the tritium residence time of Li4SiO4 made by melt spraying method at 467 ◦C is approximately 23.34 h. High-density Li4SiO4 pebbles exhibit tritium release at relatively low temperatures (<600 ◦C) that is mainly controlled by bulk diffusion. The diffusion coefficient at 525 ◦C and 550 ◦C is 1.19 × 10 11 cm2/s and 5.34 × 10 11 cm2/s, respectively, with corresponding tritium residence times of 21.3 hours and 4.7 hours.

Effect of Initial Microstructure on the Hot Deformation Behavior and Microstructure Evolution of Aluminum Alloy AA2060

Chaoyang Li,Guangjie Huang,Lingfei Cao,Ruoxi Zhang,Yu Cao,Bin Liao,Lin Lin 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

The microstructure evolution and hot deformation behavior of a Li-containing aluminum alloy AA2060 with different initialmicrostructure (homogenized vs. pre-rolled) were studied by isothermal hot deformation. The tests were performed within awide range of deformation temperatures of 370–490 ℃ and strain rates of 0.01–10 s−1. Results show that the stress drop ratioof the pre-rolled specimen is higher than that of the homogenized one under the same deformation condition. Microstructurewere analyzed on the thermal processing maps in unstable and optimum processing domain, and a higher dynamic recrystallizationfraction can be observed in the pre-rolled specimen that has more substructures and smaller grains. Four typesof the dynamic recrystallization were observed and the mechanism for deformation softening was discussed in this work.

Protective effects of vitamins C and E on dichlorodiphenyltrichloroethane-induced genotoxicity and hepatotoxicity in human liver cells

Xiao Ting Jin,Li Song,Xiang Yuan Liu,Hang Qing Li,Long Cheng,Zhuo Yu Li1,,Z. Y. Li 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.2

Dichlorodiphenoxytrichloroethane (DDT), a persistent organic pollutant and hepatotoxicant, is used to control the malaria. However, scarce information exists on relevant effective inhibitors of DDT’ toxicity. The aim of this study was to investigate protective effects of natural antioxidants vitamin C (VC) or/and vitamin E (VE) on p,pʹ-DDT-induced genotoxicity and hepatotoxicity in human liver cells. p,pʹ-DDT exposure increased levels of chromatin condensation, comet parameter, micronucleus induction and DPC coefficient of HL-7702 cells in a dose-dependent manner. Also, an increase in mRNA levels of CYP1A1 as well as CYP3A4, and a decrease in UGT along with GST were observed. Interestingly, supplementation with VC or/and VE prevented p,pʹ-DDT-caused alterations in DNA damage and phase metabolism gene expressions, and the combination of VC and VE had a more protective effect than VC or VE alone. These findings illustrated that VC or/and VE could be beneficial for the alleviation of p,pʹ-DDT-incurred toxicity in human liver cells.

Evolution of the effect of sulfur confinement in graphene-based porous carbons for use in Li-S batteries

Jia, Xiangling,Zhang, Chen,Liu, Juanjuan,Lv, Wei,Wang, Da-Wei,Tao, Ying,Li, Zhengjie,Zheng, Xiaoyu,Yu, Jong-Sung,Yang, Quan-Hong The Royal Society of Chemistry 2016 Nanoscale Vol.8 No.8

<P>A controllable drying strategy is proposed for the precise and non-destructive control over the structure of a 3D graphene assembly. Such an assembly is used as a model carbon material to investigate the pore structure-dependent shuttle effect and cycling performance of the cathode of a Li-S battery.</P>

상아질 접착 후 저장기간에 따른 접착제의 접착력 변화

조영곤,반일환,유미경 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.3

본 연구는 상아질에 2단계와 단일 단계 자가 산부식 접착제를 적용하여 복합레진을 접착한 후 저장기간에 따른 미세 인장 결합강도와 접착계면의 변화를 상호 비교하기 위하여 시행하였다. 발거된 상 ·하악 대구치 48개의 교합면측 상아질을 노출시켜 12개씩 4개의 군으로 분류하였다 사용된 접착제의 종류에 따라 SE Bond 군, AdheSE 군, Adper 군, Xeno III 군으로 분류하여 접착제를 적용한 후, 동일 회사의 복합레진 을 4 mm두께로 접착시켰다. 각 군당 4개의 치아를 선택하여 증류수가 담겨진 용기에 집어넣고 37℃의 항온기에 각각 1일 15일, 30일 동안 저장한 후 시편을 제작하여 각각 미세인장 결합강도의 측정과 주사전자 현미경 관찰 하여 다음과 같은 결과를 나타내었다. 2단계 자가 산부식 접착제는 1일에서 30간의 저장기간 동안 결합강도가 점차적으로 감소하였지만 통계학적으로 유의한 차이를 나타내지 않았고, 상아질과 접착제 간에 긴밀한 접착관계를 보였다. 반면에 단일 단계자가 산부식 접착제는 1일의 저장기간에 비해 30일의 저장기간에서 통계학적인 결합강도의 감소를 나타내었으며, 상아질과 접착제 간에 넓은 간극이 관찰되었다. 따라서 본 연구에서 나타난 두 종류의 30일 동안의 접착내구성은 2단계 자가 산부식 접착제가 단일 단계 자가 산부식 접착제보다 우수한 것으로 나타났다. This study compared the microtensile bond strength (μTBS) and microscopic change of two 2-step and two 1-step self-etching adhesives to dentin according to storage times in distilled water. Occlusal dentin was exposed in 48 human molars. They were divided to four groups by different adhesives: SE Bond group (Clearfil SE Bond), AdheSE group (AdheSE). Adper group (Adper Prompt L-Pop), and Xeno group (Xeno III). Each group was stored in 37℃ distilled water for 1, 15, and 30 days. Resin-bonded specimens were sectioned into beams and subjected to μTBS testing with a crosshead speed of 1 mm/minute. For SEM observation, one specimen was selected and sectioned in each group after each stroage time. Resin-dentin interface was observed under FE-SEM. In all storage times, mean μTBS of SE group was significantly higher than those of other groups (p < 0.05). There was no significant difference between mean μTBS of SE group and AdheSE group among all storage times, but significant difference between 1- and 30-day storage in mean μTBS of Adper group and Xeno group (p > 0.05). For 1-and 15-day storage, all groups showed the close adaptation between resin-dentin interfaces. For 30-day storage, resin-dentin interfaces showed wide gap in Adper group and separate pattern in Xeno III group. Resin-bonded specimens were sectioned into beams and subjected to μTBS testing with a crosshead speed of 1 mm/minute. For SEM observation, one specimen was selected and sectioned in each group after each stroage time. Resin-dentin interface was observed under FE-SEM. In all storage times, mean μTBS of SE group was significantly higher than those of other groups (p < 0.05). There was no significant difference between mean μTBS of SE group and AdheSE group among all storage times, but significant difference between 1- and 30-day storage in mean μTBS of Adper group and Xeno group (p > 0.05). For 1-and 15-day storage, all groups showed the close adaptation between resin-dentin interfaces. For 30-day storage, resin-dentin interfaces showed wide gap in Adper group and separate pattern in Xeno III group.

TSSG growth, morphology and properties of potassium lithium niobate (KLN) crystals

Chong, Tow-Chong,Xu, Xue-Wu,Li, Lian,Zhang, Guang-Yu,Kumagai, H.,Hirano, M. The Korea Association of Crystal Growth 1999 한국결정성장학회지 Vol.9 No.4

In the present paper, potassium lithium niobate(KLN) crystals have been grown along <001>, <100> and <110> directions by the top seeded solution growth (TSSG) method from Li-richer melts with different compositions. The morphologies of KLN crystals grown along different directions have been studied, and the well-developed facets have been unambiguously indexed using X-ray goniometer and stereographic projection analysis. The growth mechanism and defects such as cracks and inclusions were discussed on the basis of observations of facets on the crystal-solution interfaces. The crystal compositions were determined by a chemical analysis method. The structure and lattice constants of KLN crystals were determined and calculated on the basis of XRD data by using TREOR90 and PIRUM programs. The Curie temperature and optical absorption were determined by dielectric constant peak and spectrum measurements. respectively. The blue second harmonic generation (SHG) characteristics of KLN sample were also investigated using a pulsed dye laser.

Supercapacitors with ultrahigh energy density based on mesoporous carbon nanofibers: Enhanced double-layer electrochemical properties

Li, Zhen-Yu,Akhtar, M. Shaheer,Yang, O-Bong Elsevier 2015 Journal of alloys and compounds Vol.653 No.-

<P><B>Abstract</B></P> <P>High performance electrochemical double-layer (EDL) supercapacitor was fabricated with highly efficient electro-active electrode based on mesoporous carbon nanofibers (MCFs) materials. The prepared MCFs from dextrose as carbon source exhibited the high surface to volume ratio, large pore volume and high mesoporous nature. The cyclic voltammetry, electrochemical impedance and galvanostatic charge–discharge measurements were carried out to investigate the capacitive and electrochemical behavior of fabricated EDL supercapacitor based on MCFs electrode. A reasonably high specific capacitance of 201 F/g at current density of 0.6 A/g was achieved by the fabricated EDL supercapacitor based on MCFs electrode. A relation of capacitive performance, specific surface area, accessible average pore size and current density was manifested to evaluate the impact of capacitance parameters. The fabricated EDL supercapacitor based on MCFs electrode attained the ultra high energy density of 54.7 W h/kg and reasonable power density of 0.842 kW/kg at the current density of 0.6 A/g. The fabricated EDL supercapacitor manifested an excellent stability by keeping about 88% of initial capacity after 1000 cycles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Highly efficient electro-active electrode prepared by mesoporous carbon nanofibers. </LI> <LI> High performance electrochemical double layer (EDL) supercapacitor was fabricated. </LI> <LI> EDL supercapacitor with MCFs electrode showed the high specific capacitance of 201 F/g. </LI> <LI> Ultra high energy density of 54.7 W h/kg and power density of 0.842 kW/kg attained. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Reconsidering the Hierarchy and Translation of “Physical Education/Sports” Related Terms: Taiwan Perspective

Jeffrey Yu,Jun Lian,Ruei-Hong Li,Chen-Sin Hung,Dong-Tai Chen,Yu-Kai Chang 대한운동학회 2024 아시아 운동학 학술지 Vol.26 No.1

Objectives In the past centuries, the concept of “physical education” has changed from a more general concepts including physical activities and sports, to specifically inferring “instruction of physical activity”. Instead, “sports” has become the comprehensive concept of sports, exercise, and physical education. Given to the inconsistent terminologies and English translations of “體育 (ti-yu)” (physical education) and “運 動 (yun-dong)” (sports or exercise) in Mandarin, the purpose of this study was to investigate in the current terminology usage, hierarchy, and the English translation of “體育 (ti-yu)” and “運動 (yun-dong)” in Taiwan. Met hods Three government authorities, two sport related universities, eight top sport and exercise journals, and nighty-six college departments in Taiwan were analyzed. Results “運動 (yun-dong)” was the most widely used terminology as “體育 (ti-yu)” occupied the majority usage among government authorities, sport related universities, and title of top sport and exercise journals. Regarding English translation, despite of “department of physical education”, “sports” remained the most common terminology. Moreover, “體育 (ti-yu)” and “sports” are the highest hierarchy among government authorities, and sport related university; “體育 (ti-yu)” and “physical education” are the highest hierarchy among traditional sport and exercise journals; “運動 (yun-dong)” and “sports” are the highest hierarchy among college departments also the mainstream of current translation and hierarchy. Conclusions “體育 (ti-yu)” was the highest hierarchy in the past. However, “運動 (yun-dong)” has been the mainstream of the highest hierarchy in Mandarin according to college departments. In English, “sport(s)” is the main term in Taiwan when translating “體育 (ti-yu)” and 運動 (yun-dong)”, also being the highest hierarchy. On the other hand, “體育 (ti-yu)” and “physical education” are utilized regarding those departments focusing on educating PE teachers. This study expects the terminology, English translations, and hierarchy being align with the mainstream of current translation and hierarchy in the future.

Realizing highly efficient multicolor tunable emissions from Tb³⁺ and Eu³⁺ co-doped CaGd₂(WO₄)₄ phosphors via energy transfer by single ultraviolet excitation for lighting and display applications

Huang, Xiaoyong,Li, Bin,Du, Peng,Guo, Heng,Cao, Renping,Yu, Jae Su,Wang, Kai,Sun, Xiao Wei Elsevier 2018 Dyes and pigments Vol.151 No.-

<P><B>Abstract</B></P> <P>In this paper, we reported on multicolor emission tuning in Tb<SUP>3+</SUP> and Eu<SUP>3+</SUP> co-doped CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB> phosphors prepared by a traditional high-temperature solid-state reaction. Upon 380 nm ultraviolet excitation, the emission color of CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> phosphors can be readily tuned from green to yellow, orange and finally to pure red through varying the concentration ratio of Eu<SUP>3+</SUP> and Tb<SUP>3+</SUP> ions. The energy transfer mechanism from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP> was systematically investigated by photoluminescence spectra, luminescence decay times, and time-resolved spectra. The internal quantum efficiencies of these phosphors were measured, and their thermal stability was also studied. A prototype white light-emitting diode (LED) device was fabricated by using an ultraviolet chip combined with a blend of blue-emitting BaMgAl<SUB>10</SUB>O<SUB>l7</SUB>:Eu<SUP>2+</SUP> phosphors, green-emitting BaSrSiO<SUB>4</SUB>:Eu<SUP>2+</SUP> phosphors, and red-emitting CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:50%Tb<SUP>3+</SUP>,50%Eu<SUP>3+</SUP> phosphors. All the results indicate that the CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> has great potential application in lighting and displays.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> showed efficient energy-transfer from Tb<SUP>3+</SUP> to Eu<SUP>3+</SUP>. </LI> <LI> CaGd<SUB>2</SUB>(WO<SUB>4</SUB>)<SUB>4</SUB>:Tb<SUP>3+</SUP>,Eu<SUP>3+</SUP> exhibited tunable color emission under 380 nm excitation. </LI> <LI> The energy-transfer mechanism was studied in detail. </LI> <LI> Quantum efficiency and thermal stability were investigated. </LI> <LI> The proof-of-concept LED lamps were fabricated by employing phosphors and UV LEDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>