The effect of the spinning conditions on the structure of mesophase pitch-based carbon fibers by Taguchi method

Zhao Jiang,Ting Ouyang,Xiangdong Yao,Youqing Fei 한국탄소학회 2016 Carbon Letters Vol.19 No.-

Taguchi’s experimental design was employed in the melt spinning of molten mesophase pitch to produce carbon fibers. The textures of the obtained carbon fibers were radial with varied crack angles, as observed by scanning electron microscopy and polarized optical imaging. The diameter, crack angle, preferred orientation, and tensile modulus of the produced samples were examined to investigate the influence of four spinning variables. The relative importance of the variables has been emphasized for each characteristic. The results show that thicker carbon fiber can be obtained with a smaller entry angle, a higher spinning temperature, a reduced winding speed, and an increased extrusion pressure. The winding speed was found to be the most significant factor in relation to the fiber diameter. While it was observed that thicker carbon fiber generally shows improved preferred orientation, the most important variable affecting the preferred orientation was found to be the entry angle. As the entry angle decreased from 120° to 60°, the shear flow was enhanced to induce more ordered radial alignment of crystallite planes so as to obtain carbon fibers with a higher degree of preferred orientation. As a consequence, the crack angle was increased, and the tensile modulus was improved.

Rapid Structural Improvement of CVD-Grown Multi-Walled Carbon Nanotubes by Drastic Thermite Reaction

Jiang Zhao,Jing Chen,Pengcheng Zhang,Haofeng Yu,Jie Chen 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2015 NANO Vol.10 No.8

Multi-walled carbon nanotubes (MWCNTs) produced by chemical vapor deposition (CVD) are the most common commercial products at extremely low price in the market. However, due to the inherent drawbacks of CVD surroundings at temperature below ~ 1000℃, CVD-grown nanotubes usually have very disordered structure, resulting in most of their properties being much below expectations. Herein, we present a simple and energy-efficient method for improving rapidly the structure of CVD-grown MWCNTs via a drastic thermite reaction process. Direct observations from scan electron microscope (SEM) and transmission electron microscope (TEM) images, decrease of ID/IG ratios in Raman spectra, increase of the starting oxidation temperatures observed in thermogravimetric analysis (TGA), decrease of the volumetric electrical resistivity and decrease of the turn-on electric fields from 3.64 to 2.88 V/µm in field emission measurements suggest that the graphitization of MWCNTs can be effectively enhanced and the structure of nanotubes becomes more ordered after the drastic thermite reaction process.

Enhanced Field Emission from UV-Illuminated CuO Nanowires Fabricated by Thermal Oxidation of Cu Film

Jiang Zhao,Debo Wang,Yue Chen,Qiu Jin,Guoqing Wang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.5

Cupric Oxide (CuO) nanowires have been successfully synthesized by direct thermal oxidation of Cu film in air. The morphologies and structures of the synthesized materials are investigated by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results imply that CuO nanowires with well vertical arrays present very narrow sharp peaks, indicating the nanowires are highly crystalline. The effect of ultraviolet (UV) illumination on the field emission characteristics of the CuO nanowires is investigated. The turn-on electric field of UV-illuminated CuO nanowires decreases and the field enhancement factor enhances.

Decentralized Robust H∞ Output Feedback Control for Value Bounded Uncertain Large-scale Interconnected Systems

Zhao-Hui Jiang,Yong-Fang Xie,Wei-Hua Gui,Can Huang 제어·로봇·시스템학회 2010 International Journal of Control, Automation, and Vol.8 No.1

In this paper, decentralized robust H∞ output feedback control problem for large-scale interconnected system with value bounded uncertainties in the state, control input and interconnection matrices is investigated. A new bounded real lemma for the large-scale interconnected systems is derived by Lyapunov stability theory and linear matrix inequality method. Based on the new bounded real lemma, a sufficient condition expressed as matrix inequalities for the existence of a decentralized robust H∞ output feedback controller is obtained. The controller which enables the closed-loop large-scale system robust stable and satisfies the given H∞ performance is designed through a homotopy iterative method. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

Power Quality Optimal Control of Railway Static Power Conditioners Based on Electric Railway Power Supply Systems

Jiang, Youhua,Wang, Wenji,Jiang, Xiangwei,Zhao, Le,Cao, Yilong The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.5

Aiming at the negative sequence and harmonic problems in the operation of railway static power conditioners, an optimization compensation strategy for negative sequence and harmonics is studied in this paper. First, the hybrid RPC topology and compensation principle are analyzed to obtain different compensation zone states and current capacities. Second, in order to optimize the RPC capacity configuration, the minimum RPC compensation capacity is calculated according to constraint conditions, and the optimal compensation coefficient and compensation angle are obtained. In addition, the voltage unbalance ${\varepsilon}_U$ and power factor requirements are satisfied. A PSO (Particle Swarm Optimization) algorithm is used to calculate the three indexes for minimum compensating energy. The proposed method can precisely calculate the optimal compensation capacity in real time. Finally, MATLAB simulations and an experimental platform verify the effectiveness and economics of the proposed algorithm.

A One-Step System for Convenient and Flexible Assembly of Transcription Activator-Like Effector Nucleases (TALENs)

Zhao, Jinlong,Sun, Wenye,Liang, Jing,Jiang, Jing,Wu, Zhao Korean Society for Molecular and Cellular Biology 2016 Molecules and cells Vol.39 No.9

Transcription activator-like effector nucleases (TALENs) are powerful tools for targeted genome editing in diverse cell types and organisms. However, the highly identical TALE repeat sequences make it challenging to assemble TALEs using conventional cloning approaches, and multiple repeats in one plasmid are easily catalyzed for homologous recombination in bacteria. Although the methods for TALE assembly are constantly improving, these methods are not convenient because of laborious assembly steps or large module libraries, limiting their broad utility. To overcome the barrier of multiple assembly steps, we report a one-step system for the convenient and flexible assembly of a 180 TALE module library. This study is the first demonstration to ligate 9 mono-/dimer modules and one circular TALEN backbone vector in a one step process, generating 9.5 to 18.5 repeat sequences with an overall assembly rate higher than 50%. This system makes TALEN assembly much simpler than the conventional cloning of two DNA fragments because this strategy combines digestion and ligation into one step using circular vectors and different modules to avoid gel extraction. Therefore, this system provides a convenient tool for the application of TALEN-mediated genome editing in scientific studies and clinical trials.

Research of Enterprise Private Cloud Computing Platform Based on OpenStack

Jiang Yunxia,Zhao Bowen,Wang Shuqi,Sun Dongnan 보안공학연구지원센터 2014 International Journal of Grid and Distributed Comp Vol.7 No.5

The demand for computing resources is growing, but the input costs of the enterprise information system construction of the traditional way is too high, and has not the high utilization of the resources. In order to solve this contradiction, the enterprise private cloud platform architecture has been put forward based on open source system. By analyzing the mainstream open source cloud projects, the basis to choose OpenStack has been given. From the perspective of classification of the enterprise personnel, combining with the components of OpenStack, this paper expounds manufacture of the virtual image and distribution, monitor, and use of the virtual machine. At last, the user interface design is also given.

Production of Transgenic Pigs with an Introduced Missense Mutation of the Bone Morphogenetic Protein Receptor Type IB Gene Related to Prolificacy

Zhao, Xueyan,Yang, Qiang,Zhao, Kewei,Jiang, Chao,Ren, Dongren,Xu, Pan,He, Xiaofang,Liao, Rongrong,Jiang, Kai,Ma, Junwu,Xiao, Shijun,Ren, Jun,Xing, Yuyun Asian Australasian Association of Animal Productio 2016 Animal Bioscience Vol.29 No.7

In the last few decades, transgenic animal technology has witnessed an increasingly wide application in animal breeding. Reproductive traits are economically important to the pig industry. It has been shown that the bone morphogenetic protein receptor type IB (BMPR1B) A746G polymorphism is responsible for the fertility in sheep. However, this causal mutation exits exclusively in sheep and goat. In this study, we attempted to create transgenic pigs by introducing this mutation with the aim to improve reproductive traits in pigs. We successfully constructed a vector containing porcine BMPR1B coding sequence (CDS) with the mutant G allele of A746G mutation. In total, we obtained 24 cloned male piglets using handmade cloning (HMC) technique, and 12 individuals survived till maturation. A set of polymerase chain reactions indicated that 11 of 12 matured boars were transgene-positive individuals, and that the transgenic vector was most likely disrupted during cloning. Of 11 positive pigs, one (No. 11) lost a part of the terminator region but had the intact promoter and the CDS regions. cDNA sequencing showed that the introduced allele (746G) was expressed in multiple tissues of transgene-positive offspring of No.11. Western blot analysis revealed that BMPR1B protein expression in multiple tissues of transgene-positive $F_1$ piglets was 0.5 to 2-fold higher than that in the transgene-negative siblings. The No. 11 boar showed normal litter size performance as normal pigs from the same breed. Transgene-positive $F_1$ boars produced by No. 11 had higher semen volume, sperm concentration and total sperm per ejaculate than the negative siblings, although the differences did not reached statistical significance. Transgene-positive $F_1$ sows had similar litter size performance to the negative siblings, and more data are needed to adequately assess the litter size performance. In conclusion, we obtained 24 cloned transgenic pigs with the modified porcine BMPR1B CDS using HMC. cDNA sequencing and western blot indicated that the exogenous BMPR1B CDS was successfully expressed in host pigs. The transgenic pigs showed normal litter size performance. However, no significant differences in litter size were found between transgene-positive and negative sows. Our study provides new insight into producing cloned transgenic livestock related to reproductive traits.

Kocuria subflava sp. nov., isolated from marine sediment from the Indian Ocean

Jiang, Zhao,Zhang, Wei-Hua,Yuan, Chang-Guo,Chen, Jia-Yang,Cao, Li-Xiang,Park, Dong-Jin,Xiao, Min,Kim, Chang-Jin,Li, Wen-Jun Springer-Verlag 2015 Antonie van Leeuwenhoek Vol.108 No.6

Protective effect of Lactobacillus plantarum ATCC8014 on acrylamide-induced oxidative damage in rats

Zhao Sijia,Zhao Xiaoduo,Liu Qingbo,Jiang Yujun,Li Yanhua,Feng Wenxiao,Xu Honghua,Shao Meili 한국응용생명화학회 2020 Applied Biological Chemistry (Appl Biol Chem) Vol.63 No.4

Acrylamide (AA), which is mainly found in fried foods, causes neurotoxicity, genetic toxicity, carcinogenic effects, and DNA damage. This study confirms that a strain of lactic acid bacteria (Lactobacillus plantarum ATCC8014) could alleviate the toxicity of rats by inhibiting the AA-induced oxidative damage. Forty-eight adult male SD rats were randomly divided into eight groups: control group, AA group (40 mg/kg), three different doses (1 × 107 CFU/ml, 1 × 108 CFU/ ml, 1 × 109 CFU/ml of Lactobacillus plantarum ATCC8014) of prevention groups and therapeutic groups, respectively. At the end of three-week experiment, AA treatment produced a significant reduction in the rate of weight gain along with the symptoms of hind limb splay and ataxia. Histological examinations revealed various degrees of injury in five tissues. Levels of superoxide dismutase (SOD), catalase (CAT), and glutathione (GSH) in group AA rats were significantly decreased, but the level of lipid peroxidation (LPO) was significantly increased (p < 0.05). Both prevention and therapeutic groups with 1 × 109 CFU/ml of Lactobacillus plantarum ATCC8014 could effectively reduce the injury of AA to the body. However, reductions in both groups were not statistically significant.