Synthesis and Gas Adsorption Properties of Carbide-Derived Carbons from Titanium Tin Carbide

Yuanyuan Zhu,Aiguo Zhou,Jin Jia,Junjun Wang,Jiang Liu,Baolin Xing,Chuanxiang Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.4

Here we reported the synthesis of nanoporous carbide-derived carbons (CDCs) from a new precursor, titanium tin carbides (Ti2SnC), via chlorination at 400–1100℃. At low chlorination temperature (400–500℃), as-synthesized CDCs mainly consisted of amorphous carbon and chlorides. As the chlorination temperature increased up to 600℃, chlorides disappeared, and the main composition of CDCs was amorphous carbon. At high chlorination temperature, there was a trend of graphitization. The microstructure of CDCs was observed and characterized by scanning electron microscopy and transmission electron microscopy. Some graphite-like sheet structures in CDCs were found. Specific surface area (SSA) and pore volume of CDCs increased with chlorination temperature, except an abnormal decrease of the CDC chlorinated at 900℃. CDC chlorinated at 1100℃ had the largest SSA, 1580 m2 /g. In order to apply these materials as novel hydrogen/methane storage media in the area of energy efficient transport, gas adsorption properties of CDCs were measured. For CDC chlorinated at 1100℃, pore volume uptakes are 206 cm3 /g at 60 bar (25℃) for methane, and ~442 cm3 /g at 35 bar (-196℃) for hydrogen, respectively. It was suggested that CDCs from Ti2SnC are promising materials for hydrogen/ methane adsorptive storage.

A Shared Channel Design for the Power and Signal Transfers of Electric-field Coupled Power Transfer Systems

Su, Yu-Gang,Zhou, Wei,Hu, Aiguo Patrick,Tang, Chun-Sen,Hua, Rong The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

Electric-field coupled power transfer (ECPT) systems have been proposed as an alternative wireless power transfer (WPT) technology in recent years. With the use of capacitive plates as a coupling structure, ECPT systems have many advantages such as design flexibility, reduced volume of the coupling structure and metal penetration ability. In addition, wireless communications are effective solutions to improve the safety and controllability of ECPT systems. This paper proposes a power and signal shared channel for electric-field coupled power transfer systems. The shared channel includes two similar electrical circuits with a band pass filter and a signal detection resistor in each. This is designed based on the traditional current-fed push-pull topology. An analysis of the mutual interference between the power and signal transmission, the channel power and signal attenuations, and the dynamic characteristic of the signal channel are conducted to determine the values for the electrical components of the proposed shared channel. Experimental results show that the designed channel can transfer over 100W of output power and data with a data rate from 300bps to 120 kbps.

The Mathematic Model of "Pressing Complexion" Differential Coefficient Countermeasure Decision for Collision-avoidance

Cai Feng,Shi Aiguo,Yang Baozhang,Zhou Lixin 한국항해항만학회 2001 한국항해항만학회 학술대회논문집 Vol.3 No.-

In this article, we have done some analysis about the collision-avoidance specialty of "pressing complexion" and "pressing danger" in the meet process of two boats, and offered a mathematic model of differential coefficient countermeasure decision for collision-avoidance. which adapt to the right complexion. The basal idea is, in the right condition whatever do the coming boat do, and our boat will always adopt dynamic, continuous and the best countermeasure. When both the controlling capabilities of two boats have advantage and inferior position, we can working-out with the qualitative differential coefficient countermeasure.

Novel Hierarchical TiO2/C Nanocomposite with Enhanced Photocatalytic Performance

Yupeng Gao,Hao Chen,Aiguo Zhou,Zhengyang Li,Fanfan Liu,Qianku Hu,Libo Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.5

"Hierarchical TiO2 /carbon nanocomposites were synthesized by oxidation of two-dimensional(2D) Ti3C2 nanosheets at different temperatures. Crystal structures and morphologies of the obtained samples were characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and Raman spectroscopy. The results show that 2D Ti3C2 nanosheets are partially oxidized to form a novel hierarchical nanostructure which is composed of carbon nanosheets and TiO2 nanoparticles. With the calcination temperature increasing, the crystal structure of TiO2 nanoparticles changes from anatase to rutile and the hierarchical structure was gradually destroyed. The photodegradation results reveal that the samples obtained at 200℃ and 285℃ show much better photocatalytic properties than P25. And meanwhile the photocatalytic property will become worse with the increase in calcinations temperature."

A Shared Channel Design for the Power and Signal Transfers of Electric-field Coupled Power Transfer Systems

Yu-Gang Su,Wei Zhou,Aiguo Patrick Hu,Chun-Sen Tang,Rong Hua 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.2

Electric-field coupled power transfer (ECPT) systems have been proposed as an alternative wireless power transfer (WPT) technology in recent years. With the use of capacitive plates as a coupling structure, ECPT systems have many advantages such as design flexibility, reduced volume of the coupling structure and metal penetration ability. In addition, wireless communications are effective solutions to improve the safety and controllability of ECPT systems. This paper proposes a power and signal shared channel for electric-field coupled power transfer systems. The shared channel includes two similar electrical circuits with a band pass filter and a signal detection resistor in each. This is designed based on the traditional current-fed push-pull topology. An analysis of the mutual interference between the power and signal transmission, the channel power and signal attenuations, and the dynamic characteristic of the signal channel are conducted to determine the values for the electrical components of the proposed shared channel. Experimental results show that the designed channel can transfer over 100W of output power and data with a data rate from 300bps to 120 kbps.

Development of EST-SSRs from the ark shell (Scapharca broughtonii) transcriptome and their application in genetic analysis of four populations

Wenjing Wang,Biao Wu,Zhihong Liu,Liqing Zhou,Xiujun Sun,Jiteng Tian,Aiguo Yang 한국유전학회 2021 Genes & Genomics Vol.43 No.6

Background The ark shell (Scapharca broughtonii) is one of the most economically important mollusks in the Bohai Sea and Yellow Sea of China. In recent years, ark shells from the Korean population were introduced to China for seed propagation and culture. Objective To explore the impact of the introduction of Korean ark shell on the genetic diversity of native population in China. Methods Simple sequence repeat (SSR) is efective and widely used tool for genetic analysis. In this study, 180 EST-SSRs were selected and verifed by polymerase chain reaction and polyacrylamide gel electrophoresis. Subsequently, fve polymorphic EST-SSRs were screened and their primers were modifed by fuorescein for use in the genetic analysis of four populations. Results Genetic analysis showed that 361 alleles amplifed by fve SSR loci were detected in the four populations. The number of alleles for the fve SSRs ranged from 8 to 30, with a mean of 18.05 (standard deviation, SD=6.492). The efective number of alleles varied from 2.253 to 22.222, with a mean of 10.596 (SD=4.713). Observed heterozygosity and expected heterozygosity were 0.167–0.833 and 0.566–0.971, with average values of 0.520 (SD=0.177) and 0.891 (SD =0.062), respectively. Polymorphic information content ranged from 0.521 to 0.953, with a mean of 0.865 (SD=0.070). The pairwise genetic diferentiation coefcient (FST) of the four populations ranged from 0.0267 to 0.0477, showing low genetic diferentiation. The phylogenetic tree constructed by neighbor-joining method showed that the genetic distance between the Chinese Dalian native population and three Korean populations was relatively more far than that among those Korean populations. Conclusion The results indicated that the genetic structure of the Dalian wild population was less afected by the introduced Korean wild populations.

Seawater electrolyte-mediated high volumetric MXene-based electrochemical symmetric supercapacitors

Xia, Qi Xun,Shinde, Nanasaheb M.,Zhang, Tengfei,Yun, Je Moon,Zhou, Aiguo,Mane, Rajaram S.,Mathur, Sanjay,Kim, Kwang Ho The Royal Society of Chemistry 2018 Dalton Transactions Vol.47 No.26

<P>The structure and morphology of titanium carbide (Ti3C2Tx) MXene, a new class of two dimensional (2D) materials, are investigated and reported. Ti3AlC2 MAX, treated with a hydrofluoric acid etching process, is used as a promising electrode material for electrochemical supercapacitor studies. The electrochemical supercapacitor performance of Ti3C2Tx as a negatrode in a natural seawater electrolyte solution, tested in a three-electrode system, demonstrated a specific capacitance of 67.7 F g<SUP>−1</SUP> at a current density of 1 A g<SUP>−1</SUP> which is in accordance with the volumetric specific capacitance of 121.8 F cm<SUP>−3</SUP>. A symmetric supercapacitor assembled with a Ti3C2Tx//Ti3C2Tx electrode configuration revealed a volumetric specific capacitance of 27.4 F cm<SUP>−3</SUP> at 0.25 A g<SUP>−1</SUP>, and 96.6% capacitance retention even after 5000 cycles, which is superior to those reported previously in similar systems, suggesting the importance of abundant and cost-effective seawater as a natural electrolyte in developing energy storage devices.</P>

Synthesis and Electrochemical Performance of Ti3C2Tx with Hydrothermal Process

Libo Wang,Heng Zhang,Bo Wang,Changjie Shen,Chuanxiang Zhang,Qianku Hu,Aiguo Zhou,Baozhong Liu 대한금속·재료학회 2016 ELECTRONIC MATERIALS LETTERS Vol.12 No.5

In this study, a simple hydrothermal method has been developedto prepare Ti3C2Tx from Ti3AlC2 as a high-performance electrodematerial for supercapacitors. This method is environmentallyfriendly and has a low level of danger. The morphology andstructure of the Ti3C2Tx can be controlled by hydrothermalreaction time, temperature and NH4F amounts. The preparedTi3C2Tx was characterized by X-ray diffraction, field emissionscanning electron microscopy, Raman spectroscopy, X-rayphotoelectron spectroscopy and Brunauer-Emmet-Teller. Theresults show that the prepared Ti3C2Tx is terminated by O, OH,and F groups. The electrochemical properties of the Ti3C2Txsample exhibit specific capacitance up to 141 Fcm−3 in 3 MKOH aqueous electrolyte, and even after 1000 cycles, nosignificant degradation of the volumetric capacitance wasobserved. These results indicate that the Ti3C2Tx materialprepared by this hydrothermal method can be used in highperformance supercapacitors.

Structural Characterization of Microwave-Assisted Solution-Synthesized Strontium-Substituted Hydroxyapatite

Jianguo Liao,Yanqun Li,Xiali Guan,Jingxian Liu,Yongxiang Zhang,Yufen Xie,Zhengpeng Yang,Xingze Duan,Aiguo Zhou,Jiangnan Zhu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.10

Hydroxyapatite and strontium-substituted hydroxyapatite nanoparticles (n-HA and Sr-HA) were prepared by microwave-assisted solution synthesis with aqueous solutions of various Sr/(Sr+Ca) molar ratios ranging from 0% to 15%. The structural properties of the hydroxyapatite powders were investigated by X-ray powder diffraction, Fourier transform infrared spectroscopy and Raman spectra, field emission scanning electron microscopy coupled with energy dispersive X-ray spectrometry and transmission electron microscopy. The results confirmed that strontium ions had been incorporated into the hydroxyapatite lattice. The synthetic n-HA and Sr-HA nanocrystalline consisted of hydroxyapatite crystalline phase with hexagonal structure, and the particle size was 30–40 x 60–70 nm and 40–50 x 70–80 nm, respectively. The calcined HA particle size ranged from about 120 nm to 150 nm, the calcined Sr-HA products were composed of spherical aggregates with a size of about 70–100 nm. The incorporation of Sr ions lead to the formation of vacancies in the crystal structure of the HA. The results indicated that the strontium substitution did not change the crystal structures. More Sr resulted in less calcined crystallites and formed agglomerates owing to the size effect.