Effect of Zn2+ and F- Co-Modification on the Structure and Electrochemical Performance of Li4Ti5O12 Anode Material

Aijia Wei,Wen Li,Lihui Zhang,Xiaohui Li,Xue Bai,Zhenfa Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.5

Zn2+ and F- ions are successfully used to modify pure Li4Ti5O12 via a co-precipitation method followed by calcination at 400℃ for 5 h in an Ar atmosphere in order to further investigate the reaction mechanism of the fluoride modification process. Zn2+ and F- co-modified Li4Ti5O12 samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. After the modification process, no ZnF2 coating layer is formed on the surface of Li4Ti5O12, instead, F- ions react with Li4Ti5O12 to generate a new phase, composed of a small amount of anatase TiO2, rutile TiO2, LiF, and Zn2+ ions are suspected to form a ZnO coating layer on Li4Ti5O12 particles. The electrolyte reduction decomposition is suppressed in Zn2+ and F- co-modified Li4Ti5O12 due to the ZnO coating layer. 1 wt.% Zn2+ and F- co-modified Li4Ti5O12 exhibits the best rate capability, which leads to a charge capacity of 236.7, 227.8, 222.1, 202.7, 188.9 and 150.7 mAh g -1 at 0.2C, 0.5C, 1C, 3C, 5C and 10C, respectively, between 0 V and 3 V. Furthermore, 1 wt.% Zn2+ and F- comodified Li4Ti5O12 exhibits 96.0% charge capacity retention at 3C rate after 200 cycles, which is significantly higher than that of pure Li4Ti5O12 (78.4%).

Characterization of Basic Nitrogen-Containing Compounds in the Products of Lube Base Oil Processing by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Li, Xiaohui,Zhu, Jianhua,Wu, Bencheng Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.1

The distribution of basic nitrogen-containing compounds in three vacuum gas oils (VGOs) with different boiling ranges and their dewaxed oils from the lube base oil refining unit of a refinery were characterized by positive-ion electrospray ionization (ESI) Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). It turned out that the composition of basic nitrogen compounds in the samples varied significantly in DBE and carbon number, and the dominant basic N-containing compounds in these oil samples were N1 class species. $N_1O_1$, $N_1O_2$, and $N_2$ class species with much lower relative abundance were also identified. The composition of basic nitrogen compounds in VGOs and dewaxed VGOs were correlated with increased boiling point and varied in DBE and carbon numbers. The comparison of the analytical results between VGOs and dewaxed VGOs indicated that more basic N-containing compounds in VGO with low carbon number and small molecular weight tend to be removed by solvent refining in lube base oil processing.

A Comparative Study on Teacher's Narrative of School Curriculum Development in South Korea and China

Li Xiaohui 사단법인 미래융합기술연구학회 2021 아시아태평양융합연구교류논문지 Vol.7 No.4

This study is aimed to compare the difficulties and differences between South Korean and Chinese teachers in the School Curriculum Development. For this purpose, a narrative inquiry, a method of exploring individual experiences, was used. Narrative inquiry is a method of exploring individual experiences. In this study, the narrative exploration procedure presented by Clandinin and Connelly (2000) was used, and selected three Korean teachers, three Chinese teachers, having a total of 6 participants as the primary field texts. The results showed that; first, China has improved and tried harder in that the development of the school curriculum requires a demand for teachers' expertise. Second, as a "difficulty" in developing school curriculum, South Korea and China are influenced by various factors, including the personal, contextual and empirical dimensions of teachers, under different political and social backgrounds. Third, South Korea and China face the same difficulties about 'teacher relations'. Fourth, in terms of the principal's leadership, Korea and China have a common point that the principal determines the quality of the school curriculum management. Fifth, the expectations of teachers in the development of school curriculum are that Korean and Chinese teachers are also students-oriented, and they expect to expand teacher research and education opportunities related to school curriculum development, and to develop and implement related programs for school curriculum development.

Efficient biosorption of Pb(II) from aqueous solutions by a PAH-degrading strain Herbaspirillum chlorophenolicum FA1

Xiaohui Li,Hongxia Xu,Bin Gao,Xiaoqing Shi,Yuanyuan Sun,Jichun Wu 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.57 No.-

For the first time, biosorption of lead(II) using a PAHs-degrading bacterium, Herbaspirillum chlorophenolicum FA1, was investigated as a function of initial lead concentration, biomass dosage, pH, and temperature in batch conditions. Results showed that FA1 was highly resistant to lead and grew well even at lead concentration of 200 mg L−1. The kinetic and isotherm data were well described by commonly used models, such as the pseudo-second-order and Langmuir models. Adsorption thermodynamics was spontaneous and endothermic, and FA1 exhibited a high sorption capacity of 151.52 mg g−1. SEM-EDS and FTIR analysis was conducted to further explore the interaction mechanisms.

Separation and Characterization of Organic Chlorides in a Chinese Crude Oil

Xiaohui Li,Rui Ma,Liang Ding,Huiying Yuan,Bencheng Wu,Jianhua Zhu 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.4

A crude oil from Shengli oilfield of China was extracted with N,N‐dimethylformamide (DMF) for separation and enrichment of organic chlorides. The resulting extract with relatively higher chlorine concentration was analyzed with gas chromatography–mass spectrometry (GC/MS). Among the identified heteroatom compounds in the extract sample, nitrogen‐containing compounds were most abundant in the extract sample, followed by chlorine‐, sulfur‐, and oxygen‐containing compounds, respectively. Four organochlorines with an aromatic core structure, i.e., 5‐chloro‐2‐methylaniline, 2‐chloro‐6‐methylaniline, 4‐chloro‐2‐nitrotoluene, and 1‐(5‐chloro‐2‐hydroxyphenyl)ethanone, were identified from crude oil extract. The dominant abundant organic chloride is 5‐chloro‐2‐methylaniline with relative content of 65.1% in the total of identified organic chlorides, followed by 1‐(5‐chloro‐2‐hydroxyphenyl)ethanone of 16.3%, 2‐chloro‐6‐methylaniline of 14.5%, and 4‐chloro‐2‐nitrotoluene of 4.1%, respectively.

Hair follicles transcriptome profiles in Bashang long-tailed chickens with different plumage colors

Xiaohui Liu,Rongyan Zhou,Yongdong Peng,Chuansheng Zhang,Lanhui Li,Chunxiang Lu,Xianglong Li 한국유전학회 2019 Genes & Genomics Vol.41 No.11

Despite the rich variety in plumage color found in nature, genetic studies on how hair follicles affect pigmentation are often limited to animals that have black and white pigment. To test how gene expression influences plumage color, transcriptomes of chicken hair follicles with white, black, hemp, reed catkins, silvery grey, and landscape plumage colors were generated using Illumina sequencing. We generated six RNA-Seq libraries with over 25 million paired-end clean reads per library with percentage of paired-end clean reads ranging from 96.73 to 96.98%. 78% of the reads mapped to the chicken genome, and approximately 70% of the reads were mapped to exons and 6% mapped to introns. Transcriptomes of hair follicles producing hemp and land plumage were similar, but these two showed moderate differences compared with gray and reed colored plumage. The black and white follicle transcriptomes were most divergent from the other colors. We identified several candidate genes, including GPNMB, PMEL, TYRP1, GPR143, OCA2, SOX10, SLC45A2, KRT75, and TYR . All of these genes are known to induce pigment formation in mice. White feathers result from the lack of pigment formation, and our results suggest that the white chickens due to the recessive insertion mutation of TYR . The formation of black area size and color depth may be due to the expression levels of GPNMB, PMEL, TYRP1, GPR143, OCA2, SOX10, SLC45A2, KRT75, and TYR . The GO analysis of the differentially expressed genes (DEGs) revealed that DEGs in our transcriptome analysis were enriched in cytoskeleton and cell structure related pathways. The black plumage transcriptome showed significant differences in melanogenesis, tyrosine metabolism, and riboflavin metabolism compared with transcriptomes of other plumage colors. The transcriptome profiles of the different chicken plumage colors provide a valuable resource to understand how gene expression influences plumage color, and will be an important resource for identifying candidate genes in breeding programs.

Trust Based Service Optimization Selection for Cloud Computing

Xiaohui Li,Jingsha He,Ying Du 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.5

We present an approach for privacy preservation in cloud computing environment in which we propose to use information entropy and rough set theory with the goal of personalized privacy protection in cloud users during service selection based on trust. In the approach, cloud server is as an active service provider to personalize the cloud user privacy, cloud user selects the service which is quantified by trust for multi-tenant personalized privacy protection needs. We descript user privacy information by the service and trust attributes, design a multi-attribute service quantization algorithm using information entropy and rough set theory for the quality of service. The approach can achieve the purpose of quantitative service and dynamically adjust the supply relationship service based on multi-attribute, analysis shows which can effectively protect user privacy and personalization by quantifying the cloud service.

Characterization of Basic Nitrogen-Containing Compounds in the Products of Lube Base Oil Processing by Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry

Xiaohui Li,Jianhua Zhu,Bencheng Wu 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.1

The distribution of basic nitrogen-containing compounds in three vacuum gas oils (VGOs) with different boiling ranges and their dewaxed oils from the lube base oil refining unit of a refinery were characterized by positive-ion electrospray ionization (ESI) Fourier transform-ion cyclotron resonance mass spectrometry (FT- ICR MS). It turned out that the composition of basic nitrogen compounds in the samples varied significantly in DBE and carbon number, and the dominant basic N-containing compounds in these oil samples were N 1 class species. N 1 O 1 , N 1 O 2 , and N 2 class species with much lower relative abundance were also identified. The composition of basic nitrogen compounds in VGOs and dewaxed VGOs were correlated with increased boiling point and varied in DBE and carbon numbers. The comparison of the analytical results between VGOs and dewaxed VGOs indicated that more basic N-containing compounds in VGO with low carbon number and small molecular weight tend to be removed by solvent refining in lube base oil processing.

A Generous Cooperative Routing Protocol for Vehicle-to-Vehicle Networks

( Xiaohui Li ),( Junfeng Wang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.11

In vehicle-to-vehicle (V2V) networks, where selfishness degrades node activity, countermeasures for collaboration enforcement must be provided to enable application of a sage and efficient network environment. Because vehicular networks feature both high mobility and various topologies, selfish behavior judgment and establishment of a stable routing protocol become intensely challenging. In this paper, a two-phase-based generous cooperative routing protocol (called GEC) is presented for V2V networks to provide resistance to selfishness. To detect selfish behaving vehicles, a packet forwarding watchdog and an average connection rate based on the multipath weight method are used, where evidence is gathered from different watchdogs. Then, multihop relay decisions are made using a generous cooperative algorithm based on game theory. Finally, through buffering of the multiple end-to-end paths and judicious choice of optimal cooperative routes, route maintenance phase is capable of dealing with congestion and rapidly exchanging traffic. Specifically, it is proved that the GEC is theoretically subgame perfect. Simulation results show that for V2V networks with inherently selfish nodes, the proposed method isolates uncooperative vehicles and is capable of accommodating both the mobility and congestion circumstances by facilitating information dissemination and reducing end-to-end delay.

The Comparative Study on Management of School-based Curriculum in South Korea and China

Li Xiaohui 사단법인 미래융합기술연구학회 2019 아시아태평양융합연구교류논문지 Vol.5 No.3

In order for schools to be effective in teaching guidance, it is necessary to support the process of organizing, operating, and evaluating the school curriculum effectively and efficiently. Effective support and maintenance of this process can be regarded as curriculum management. The operation of school curriculum is one of the curriculum management. In a broad sense, it is educational activity itself, but in the narrow sense it is classroom operation. The purpose of this study is to analyze what kind of difference exists between Korea and China in school curriculum in terms of school curriculum management plan. The process of planning the school curriculum is divided into planning stage, practice stage, and evaluation stage.