Self-assembly and Mechanism of L-Alanine-based Dihydrazide Derivative as Excellent Gelator of Organic Solvents

Wang, Chuan-Sheng,Wang, Xiao-Hong,Li, Zhi-Yuan,Wei, Wei,Shi, Zhong-Liang,Sui, Zhi-Tong Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.4

A new organogelator, L-Alanine dihydrazide derivative can self-assemble in various organic solvents and turned them into thermally reversible physical supramolecular organogels at extremely low concentrations (< 2 wt %). The gel-sol phase transition temperatures ($T_{GS}$) were determined as a function of gelator concentration and the corresponding enthalpies (${\Delta}H_g$) were extracted. Scanning electron microscopy (SEM) measurements revealed that the interspaces of fiber-like network structures were diminished with the increasing of the LMOG concentration. FT-IR spectroscopy studies revealed that hydrogen-bonding and hydrophobic interaction were the driving forces for the formation of the gels. Based on the data of XRD and molecular modeling, the possible packing modes for the formation of organogelator aggregates were proposed.

Self-adjusting strategy based on rotating injection for sensorless control of high-power PMSM drives

Xiaofan Wang,Xiaochun Fang,Zhi Wang,Zhihong Zhong,Yizhi Wang,Fei Lin,Zhongping Yang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

As a sensorless control method suitable for permanent magnet synchronous motor (PMSM) at lowspeed, rotating high-frequency injection method will face some special problems in high power applications. On the one hand, the low switching frequency limits the injected signal frequency, which is very close to the fundamental frequency. On the other hand, under heavy load conditions, the fundamental current amplitude is several hundred times of the negative sequence current. This will result in difficulty in signal extraction. In this paper, current spectrum is analyzed quantitatively based on the parameters of PMSM drive for rail vehicles, which illustrates the limitations of conventional bandpass filters. A method based on self-adjusting filter is proposed. The negative sequence current is successfully extracted, and the precise rotor position is obtained under the condition of variable speed and variable load. Based on a fullscale test platform the effectiveness of the proposed method is proved.

Continuous Sheet Metal Forming for Doubly Curved Surface Parts

Zhong-Yi Cai,Ying-Wu Lan,Ming-Zhe Li,Zhi-Qing Hu,Mi Wang 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

Continuous sheet metal forming (CSMF) is a novel technology for manufacturing doubly curved sheet metal parts. In this process,an upper flexible roll and two lower flexible rolls are employed as a forming tool, with the rotation of flexible rolls, the sheet metal is bent in the longitudinal and transverse directions simultaneously. In this study, the basic principle of CSMF system is introduced and the basic mathematical model to control the CSMF process is presented. Based on the analysis of the sheet metal deformation in longitudinal direction, the formulations to determine the finial curvature of the deformed sheet metal and to estimate the downward displacement of upper roll are obtained. Forming experiments for torus-shaped surface and saddle-shaped surface were carried out. The dimensional accuracy and smoothness of the CSMF parts were measured and analyzed. The experiment results confirm the validity of the presented mathematical models and shows that CSMF can be effectively used in forming of doubly curved surface parts.

Abietane Diterpenoids from Perovskia atriplicifolia and Their Anti-HBV Activities

Zhi-Yong Jiang,Zhong-Qiu Li,Chao-Guan Huang,Jun Zhou,Qiu-Fen Hu,Wen-Xing Liu,Xiang-Zhong Huang,Wei Wang,Li-Zhu Zhang,Fu-Ting Xia 대한화학회 2015 Bulletin of the Korean Chemical Society Vol.36 No.2

Bioassay-guided phytochemical investigation on the 90% EtOH extract of Perovskia atriplicifolia resulted in the isolation of eight abietane diterpenoids, including three new ones (1–3). Based on spectroscopic methods involving 1D and 2D NMR spectroscopy techniques, mass spectrometry, and optical rotation, the structures of the new compounds (1–3) were unambiguously characterized. Compounds 1–2 and 4–8 were evaluated for their anti-HBV (hepatitis B virus) activity in HepG 2.2.15 cell line. Results suggested rosmadial (8) had the most anti-HBV potency, suppressing the secretion of HBsAg and HBeAg, with IC50 values of 0.09 and 0.34 mM, respectively.

Unconventional superconductivity of NdFeAsO_0.82F_0.18 indicated by the low temperature dependence of the lower critical field <i>H</i>_c1

Wang, X L,Dou, S X,Ren, Zhi-An,Yi, Wei,Li, Zheng-Cai,Zhao, Zhong-Xian,Lee, Sung-IK IOP Pub 2009 Journal of physics, an Institute of Physics journa Vol.21 No.20

<P>We measured the initial <I>M</I>–<I>H</I> curves for a sample of the newly discovered superconductor NdFeAsO<SUB>0.82</SUB>Fe<SUB>0.18</SUB>, which had a critical temperature, <I>T</I><SUB>c</SUB>, of 51 K and was fabricated at the high pressure of 6 GPa. The lower critical field, <I>H</I><SUB>c1</SUB>, was extracted from the deviation point of the Meissner linearity in the <I>M</I>–<I>H</I> curves, which show linear temperature dependence in the low temperature region down to 5 K. The <I>H</I><SUB>c1</SUB>(<I>T</I>) indicates no s-wave superconductivity, but rather an unconventional superconductivity with a nodal gap structure. Furthermore, the linearity of <I>H</I><SUB>c1</SUB> at low temperature does not hold at high temperature, but shows other characteristics, indicating that this superconductor might have multi-gap features. Based on the low temperature nodal gap structure, we estimate that the maximum gap magnitude Δ<SUB>0</SUB> = (1.6 ± 0.2)  <I>k</I><SUB>B</SUB><I>T</I><SUB>c</SUB>.</P>

Whole-genome resequencing reveals domestication and signatures of selection in Ujimqin, Sunit, and Wu Ranke Mongolian sheep breeds

Wang Hanning,Zhong Liang,Dong Yanbing,Meng Lingbo,Ji Cheng,Luo Hui,Fu Mengrong,Qi Zhi,Mi Lan 아세아·태평양축산학회 2022 Animal Bioscience Vol.35 No.9

Objective: The current study aimed to perform whole-genome resequencing of Chinese indigenous Mongolian sheep breeds including Ujimqin, Sunit, and Wu Ranke sheep breeds (UJMQ, SNT, WRK) and deeply analyze genetic variation, population structure, domestication, and selection for domestication traits among these Mongolian sheep breeds.Methods: Blood samples were collected from a total of 60 individuals comprising 20 WRK, 20 UJMQ, and 20 SNT. For genome sequencing, about 1.5 μg of genomic DNA was used for library construction with an insert size of about 350 bp. Pair-end sequencing were performed on Illumina NovaSeq platform, with the read length of 150 bp at each end. We then investigated the domestication and signatures of selection in these sheep breeds.Results: According to the population and demographic analyses, WRK and SNT populations were very similar, which were different from UJMQ populations. Genome wide association study identified 468 and 779 significant loci from SNT vs UJMQ, and UJMQ vs WRK, respectively. However, only 3 loci were identified from SNT vs WRK. Genomic comparison and selective sweep analysis among these sheep breeds suggested that genes associated with regulation of secretion, metabolic pathways including estrogen metabolism and amino acid metabolism, and neuron development have undergone strong selection during domestication.Conclusion: Our findings will facilitate the understanding of Chinese indigenous Mongolian sheep breeds domestication and selection for complex traits and provide a valuable genomic resource for future studies of sheep and other domestic animal breeding. Objective: The current study aimed to perform whole-genome resequencing of Chinese indigenous Mongolian sheep breeds including Ujimqin, Sunit, and Wu Ranke sheep breeds (UJMQ, SNT, WRK) and deeply analyze genetic variation, population structure, domestication, and selection for domestication traits among these Mongolian sheep breeds. Methods: Blood samples were collected from a total of 60 individuals comprising 20 WRK, 20 UJMQ, and 20 SNT. For genome sequencing, about 1.5 μg of genomic DNA was used for library construction with an insert size of about 350 bp. Pair-end sequencing were performed on Illumina NovaSeq platform, with the read length of 150 bp at each end. We then investigated the domestication and signatures of selection in these sheep breeds. Results: According to the population and demographic analyses, WRK and SNT populations were very similar, which were different from UJMQ populations. Genome wide association study identified 468 and 779 significant loci from SNT vs UJMQ, and UJMQ vs WRK, respectively. However, only 3 loci were identified from SNT vs WRK. Genomic comparison and selective sweep analysis among these sheep breeds suggested that genes associated with regulation of secretion, metabolic pathways including estrogen metabolism and amino acid metabolism, and neuron development have undergone strong selection during domestication. Conclusion: Our findings will facilitate the understanding of Chinese indigenous Mongolian sheep breeds domestication and selection for complex traits and provide a valuable genomic resource for future studies of sheep and other domestic animal breeding.

Fire performance of concrete-filled steel tubular columns strengthened by CFRP

Zhong Tao,Zhi-Bin Wang,Lin-Hai Han,Brian Uy 국제구조공학회 2011 Steel and Composite Structures, An International J Vol.11 No.4

With the increasing use of concrete-filled steel tubes (CFST) as structural members, there is a growing need to provide suitable measures for possible strengthening or repair of these kinds of structural elements. Fibre reinforced polymer (FRP) jacketing is a recent method and is particularly attractive in which it does not significantly increase the section size, and is relatively easy to install. Thus, it can be used to enhance strength and/or ductility of CFST members. Very little information is available on the performance of FRP-strengthened CFST members under fire conditions. This paper is an attempt to study the fire performance of CFST columns strengthened by FRP. The results of fire endurance tests on FRP-strengthened circular CFST columns are presented. Failure modes of the specimens after exposure to fire, temperatures in the cross section, axial deformation and fire resistance of the composite columns are analysed. It is demonstrated that the required fire endurance can be achieved if the strengthened composite columns are appropriately designed.

Radar Range Superresolution Based on System Identification

Zhi Win Liu,Zhong Wang,You An Ke 대한전자공학회 1993 JTC-CSCC : Joint Technical Conference on Circuits Vol.- No.-

The antimicrobial activity of as-prepared silver-loaded phosphate glasses and zirconium phosphate

Wang Jing,Ji Zhi Jiang,Shui Zhong He,Yang Yang,Zhao Chun Yan,Wang Xiao Yan 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.3

The antimicrobial activities of silver-loaded zirconium phosphate (JDG) and silver-loaded phosphate glasses (ZZB) against Escherichia coli were studied. Although the silver content in JDG was higher than that in ZZB, ZZB suspensions showed better antimicrobial property than JDG suspensions, especially at low concentrations. The antimicrobial activity was analyzed using minimum inhibitory concentrations, bacterial inhibition ring tests, and detection of silver ions in the suspensions. Furthermore, the amounts of silver ions in suspensions with/without bacterial cells were analyzed. Results revealed that only a portion of released silver ions could be adsorbed by E. coli cells, which are critical to cell death. The damaged microstructures of E. coli cells observed by transmission electron microscopy may further prove that the adsorbed silver ions play an important role in the antimicrobial process.

Cytotoxic Isoflavanones from Uraria clarkei

Xiang-Zhong Huang,Xi-Shan Bai,Hui Liang,Chao Wang,Wen-Juan Li,Junming Guo,Zhi-Yong Jiang 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.5

Two new isoflavanones, (3R) 5,7,3',4'-tetrahydroxy-2'-methoxyisoflavanone (1) and (3R) 5',8-di-(γ,γ- dimethylallyl)-2',5-dihydroxyl-4',7-dimethoxyl-isoflavanone (2), were isolated from Uraria clarkei, together with two known compounds dalbergioidin (3), 5,7-dihydroxy-2',4'-dimethoxyisoflavanone (4). The structures involving the absolute configuration of the new compounds were well elucidated by MS, IR, UV, CD, 1D and 2D NMR analyses. Cytotoxicity of the four compounds were assessed, results suggested that compound 2 possessed well cytotoxic activity, against the Hela, K562, and HL60 cell lines with IC50 values of 28.0, 40.6 and 35.1 μM, respectively.