Microwave Synthesis of Hydrotalcite by Urea Hydrolysis

Zhiqiang Yang,Kwang-Min Choi,Nanzhe Jiang,박상언 대한화학회 2007 Bulletin of the Korean Chemical Society Vol.28 No.11

Hydrotalcite, layered double hydroxides (LDH), with hexagonal morphology has been rapidly synthesized by microwave reaction within 1 hour by urea hydrolysis from homogeneous solution. Different synthesis parameters, Mg/Al molar ratio, microwave reaction temperature and microwave power were systematically investigated. Pure hydrotalcite phase was obtained for Mg/Al ratios of 2:1 and 3:1, and higher reaction temperature gave higher crystallinity. The hydrotalcite synthesized at 600W power shows the highest crystallinity and more homogeneous crystal size distribution. The hydrotalcite samples were characterized by powder X-ray diffraction (XRD), simultaneous thermogravimetric/differential thermal analysis (TG/DTA), Fourier Transform Infrared (FT-IR) and Scanning electron micrograph (SEM).

Microwave Synthesis of Hydrotalcite by Urea Hydrolysis

Yang, Zhiqiang,Choi, Kwang-Min,Jiang, Nanzhe,Park, Sang-Eon Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.11

Hydrotalcite, layered double hydroxides (LDH), with hexagonal morphology has been rapidly synthesized by microwave reaction within 1 hour by urea hydrolysis from homogeneous solution. Different synthesis parameters, Mg/Al molar ratio, microwave reaction temperature and microwave power were systematically investigated. Pure hydrotalcite phase was obtained for Mg/Al ratios of 2:1 and 3:1, and higher reaction temperature gave higher crystallinity. The hydrotalcite synthesized at 600W power shows the highest crystallinity and more homogeneous crystal size distribution. The hydrotalcite samples were characterized by powder X-ray diffraction (XRD), simultaneous thermogravimetric/differential thermal analysis (TG/DTA), Fourier Transform Infrared (FT-IR) and Scanning electron micrograph (SEM).

Microwave Synthesis of Layered Double Hydroxide

( Zhiqiang Yang ),박상언 한국공업화학회 2006 한국공업화학회 연구논문 초록집 Vol.2006 No.-

Genetic Diversity of Hard Ticks (Acari: Ixodidae) in the South and East Regions of Kazakhstan and Northwestern China

Yicheng Yang,Jin Tong,Hongyin Ruan,Meihua Yang,Chunli Sang,Gang Liu,Wurelihazi Hazihan,Bin Xu,Sandor Hornok,Kadyken Rizabek,Kulmanova Gulzhan,Zhiqiang Liu,Yuanzhi Wang 대한기생충학열대의학회 2021 The Korean Journal of Parasitology Vol.59 No.1

To date, there is no report on the genetic diversity of ticks in these regions. A total of 370 representative ticks from the south and east regions of Kazakhstan (SERK) and Xinjiang Uygur Autonomous Region (XUAR) were selected for molecular comparison. A fragment of the mitochondrial cytochrome c oxidase subunit I (cox1) gene, ranging from 631 bp to 889 bp, was used to analyze genetic diversity among these ticks. Phylogenetic analyses indicated 7 tick species including Hyalomma asiaticum, Hyalomma detritum, Hyalomma anatolicum, Dermacentor marginatus, Rhipicephalus sanguineus, Rhipicephalus turanicus and Haemaphysalis erinacei from the SERK clustered together with conspecific ticks from the XUAR. The network diagram of haplotypes showed that i) Hy. asiaticum from Almaty and Kyzylorda Oblasts together with that from Yuli County of XUAR constituted haplogroup H-2, and the lineage from Chimkent City of South Kazakhstan was newly evolved; and ii) the R. turanicus ticks sampled in Israel, Almaty, South Kazakhstan, Usu City, Ulugqat and Baicheng Counties of XUAR were derivated from an old lineage in Alataw City of XUAR. These findings indicate that: i) Hy. asiaticum, R. turanicus and Ha. erinacei shared genetic similarities between the SERK and XUAR; and ii) Hy. marginatum and D. reticulatus show differences in their evolution.

In situ Copolymerized Toughened Polymethyl Methacrylate (PMMA) with Highly Transparency for Support Film of Polarizers

Yingying Wang,Bin Yang,Liangyong He,Yuqing Yang,Nuo Zhang,Yang Wang,Zhiqiang Shi,Yuchao Ke,Lifen Su,Jia-Sheng Qian,RU XIA,Tao Jiang 한국고분자학회 2022 폴리머 Vol.46 No.5

In this study, a series of poly(methyl methacrylate) (PMMA) copolymer films were prepared via solutionpolymerization of methyl methacrylate (MMA) with butyl acrylate (BA) and lauryl methacrylate (LMA) as monomers. Mechanical properties, hydrophobic properties, and optical properties of the films were intensively investigated. The rheological results showed that the fluidity of the copolymer was considerably enhanced. When the monomer ratio ofMMA:BA:LMA was 100:30:10, the copolymer film S4 showed the best overall performance with perfect optical transparency maintained. The results of the dynamic mechanical and thermal analysis suggested that the glass transition temperature (Tg) moved towards lower temperature, with enhanced ductility of the PMMA films. A large number of yieldfolds and crazes appeared on the cross-sectional surface of copolymer films through morphological observations, displaying the obvious characteristics of toughness fracture and obeying the energy dissipation mechanism of cracks shearband. The present study provided a facile way of preparing PMMA films with high toughness and light transmittanceby appropriate selection of the monomers, which will be of practical significance for further studies on the replacementof triacetyl cellulose as a support film of polarizers.

Attitude estimation: with or without spacecraft dynamics?

Yang, Yaguang,Zhou, Zhiqiang Techno-Press 2017 Advances in aircraft and spacecraft science Vol.4 No.3

Kalman filter based spacecraft attitude estimation has been used in many space missions and has been widely discussed in literature. While some models in spacecraft attitude estimation include spacecraft dynamics, most do not. To our best knowledge, there is no comparison on which model is a better choice. In this paper, we discuss the reasons why spacecraft dynamics should be considered in the Kalman filter based spacecraft attitude estimation problem. We also propose a reduced quaternion spacecraft dynamics model which admits additive noise. Geometry of the reduced quaternion model and the additive noise are discussed. This treatment is easier in computation than the one with full quaternion. Simulations are conducted to verify our claims.

Development of Optimization Parameter System for AVC in Hebei Low Voltage Grid

Yang, Xiao,Gao, Zhiqiang,Fan, Hui The Korean Institute of Electrical Engineers 2014 The Journal of International Council on Electrical Vol.4 No.1

Proposing the optimal AVC coordinating parameters and comparing effects of different grid planning for reactive balance in an scientific manner is one of the functional characteristics of smart AVC. In this paper Optimization Parameter (OP) system is developed in Hebei low voltage grid for this purpose. The data are taken from EMS. The state estimation is carried out periodically after obtaining real-time data. Taking state estimation results as the basic power flow and simulating AVC operations, the voltage variations and line loss analysis can be calculated for comparison. The system can compare optimization parameters for the real grid or the virtual grid. It's depending on whether considering the actual capacity of reactive power compensation equipments. The structure, hardware configuration and data exchange of the system are illustrated. Finally, several analysis tools of the OP system are introduced. With the system, it can be evaluated that effects of reducing line loss benefited from the AVC operations. It can propose coordinating priority of capacitors or on-load regulating transformers. Also it can provide the optimal AVC coordinating parameters and the optimal grid plans, which lead to better voltage control and better layout of reactive power compensation equipments.

A Highly Efficient Aeroelastic Optimization Method Based on a Surrogate Model

Zhiqiang, Wan,Xiaozhe, Wang,Chao, Yang The Korean Society for Aeronautical and Space Scie 2016 International Journal of Aeronautical and Space Sc Vol.17 No.4

This paper presents a highly efficient aeroelastic optimization method based on a surrogate model; the model is verified by considering the case of a high-aspect-ratio composite wing. Optimization frameworks using the Kriging model and genetic algorithm (GA), the Kriging model and improved particle swarm optimization (IPSO), and the back propagation neural network model (BP) and IPSO are presented. The feasibility of the method is verified, as the model can improve the optimization efficiency while also satisfying the engineering requirements. Moreover, the effects of the number of design variables and number of constraints on the optimization efficiency and objective function are analysed in detail. The accuracy of two surrogate models in aeroelastic optimization is also compared. The Kriging model is constructed more conveniently, and its predictive accuracy of the aeroelastic responses also satisfies the engineering requirements. According to the case of a high-aspect-ratio composite wing, the GA is better at global optimization.

Genetic structure analysis of mantis shrimp Oratosquilla oratoria based on mitochondrial DNA control region sequence

Yang Zhang,Zhiqiang Han,Tianxiang Gao,Huilai Shi 한국유전학회 2018 Genes & Genomics Vol.40 No.9

The genetic relationships of mantis shrimp Oratosquilla oratoria between the coastal waters of China and Japan were not well studied. To reveal the genetic differentiation and genetic structure among populations, we collected populations of mantis shrimp O. oratoria from the coastal waters of China and Japan to analyze the mtDNA control region variation. A total of 309 individuals of O. oratoria were collected from 13 localities (11 from China and 2 from Japan) and a segment of mitochondrial DNA control region was sequenced. Three hundred nine haplotypes were defined, yielding a very high haplotype diversity and nucleotide diversity. Two lineages of O. oratoria were revealed and displayed strong differences in the geographical distribution. In the coastal waters of China, the geographic distribution of the two lineages was completely separated by the Yangtze River estuary; however, the lineages showed geographic sympatry in two populations from Japan. Based on the lineage distribution, three groups were defined. There was no significant genetic differentiation among the populations within the three groups, indicating high gene flow within each group. Significant and negative values for Tajima D and Fu’s Fs tests, and mismatch distributions for two lineages indicated population expansion. The present result confirmed that the freshwater outflow from the Yangtze River formed a physical barrier and affected gene exchange. The different distribution patterns of the two lineages in coastal waters of China and Japan indicated that the larvae of O. oratoria were transferred from China to the coastal waters of Japan with a one-way gene flow.

Antioxidative Activity and Irritation Response of Lespedeza bicolor

Yang-Suk Lee,Zhiqiang Chang,Seung-Chun Park,Nac-Ryong Rim,Nam-Woo Kim 한국독성학회 2005 Toxicological Research Vol.21 No.2

In the present study, we evaluated the free radical scavenging and xanthine oxidase inhibitory activities exhibited by extracts obtained from the dried stems (and leaves) of Lespedeza bicolor. We also assessed its potential irritation activities with regard to cosmetic use. When the DPPH radical scavenging activities of L. bicolor were assessed at six different concentrations (0, 50, 100, 250, 500 and 1000 ㎍/㎖), the concentration of L. bicolor required to inhibit DPPH radical formation by 50% was found to be 164.90 ㎍/㎖. The effects of L. bicolor on the inhibition of xanthine oxidase were determined at seven different concentrations. The 50% effective concentration was found to be 282.75 ㎍/㎖. In the skin irritation test, all animals survived for the duration of the study, and all exhibited normal gains in body weight. The control sites exhibited no response to the control procedures. No edema, erythema, or eschar formation was observed in any of the tested rabbits. In the ocular irritation study, all of the rabbit eyes remained normal. In summary, L. bicolor extracts were considered to be non-irritating to the skin and eye.