Characterization and Antioxidant Activity of the Exopolysaccharide Produced by Bacillus amyloliquefaciens GSBa-1

( Wen Zhao ),( Jian Zhang ),( Yun-yun Jiang ),( Xiao Zhao ),( Xiao-na Hao ),( Liu Li ),( Zhen-nai Yang ) 한국미생물생명공학회(구 한국산업미생물학회) 2018 Journal of microbiology and biotechnology Vol.28 No.8

The exopolysaccharide (EPS) produced by Bacillus amyloliquefaciens GSBa-1 was isolated and purified by ethanol precipitation, and DEAE-cellulose and Sepharose CL-6B chromatographies. The molecular mass of the purified EPS was determined to be 54 kDa. Monosaccharide analysis showed that the EPS was composed of predominantly glucose, and it was further confirmed by NMR spectroscopy to be α-glucan that consisted of a trisaccharide repeating unit with possible presence of two α-(1→3) and one α-(1→6) glucosidic linkages. Microstructural analysis showed that the EPS appeared as ellipsoid or globose with a smooth surface. The EPS had a degradation temperature at 240℃. Furthermore, the EPS had strong DPPH and hydroxyl radical scavenging activities, and moderate superoxidant anion scavenging and metal ion-chelating activities. This is the first characterization of a glucan produced by B. amyloliquefaciens with strong antioxidant activity. The results of this study suggest the potential of the EPS from B. amyloliquefaciens GSBa-1 to serve as a natural antioxidant for application in functional products.

Study on the bio-function of lipA gene in Aspergillus flavus

Wenzhao Bai,Tiejun Feng,Faxiu Lan,Guanglan Lin,Guanglan Lin,Opemipo Esther Fasoyin,Yaju Liu,Kunzhi Jia 한국유전학회 2019 Genes & Genomics Vol.41 No.1

Lipoic acid synthase (LipA) plays a role in lipoic acid synthesis and potentially affects the levels of acetyl-CoA, the critical precursor of tricarboxylic acid (TCA) cycle. Considering the potential effect of LipA on TCA cycle, whether the enzyme is involved in the growth and aflatoxin B1 (AFB1) biosynthesis, the significant events in Aspergillus flavus is yet known. The study was designed to explore the role of lipA gene in A. flavus, including growth rate, conidiation, sclerotia formation, and biosynthesis of AFB1. LipA coding lipoic acid synthetase was knocked out using homologous recombination. The role of lipA gene in A. flavus morphogenesis (including colony size, conidiation, and sclerotia formation) was explored on various media, and the bio-function of lipA gene in the biosynthesis of AFB1 was analyzed by thin layer chromatography analysis. The growth was suppressed in △lipA. The formation of conidia and sclerotia was also reduced when lipA gene was deleted. Moreover, AFB1 was down-regulated in ΔlipA compared with WT controls. LipA plays a role in the development of A. flavus and AFB1 biosynthesis, contributing to the full understanding of the lipA bio-function in A. flavus.

Reliability and sensitivity analysis of bridge crane structure

Wenzhao Li,Ruigang Yang,Qisong Qi,Guangli Zhao 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.9

In this paper, the structural reliability and sensitivity of bridge crane have analyzed and calculated. A comprehensive evaluation framework of structural reliability and global sensitivity of bridge crane under two dangerous conditions and multiple uncertain factors is proposed. In order to simulate the typical failure modes under two dangerous conditions, the calculation is based on the high fidelity finite element model (FEM) of bridge crane. For calculation methods, the framework includes: high-precision Monte Carlo simulation (MCS) scheme for verification and high-efficiency artificial neural network (ANN)-based scheme for application. The reliability results show that the accuracy of the calculation results based on artificial neural network is acceptable (the relative errors are -0.86 %, -10 %, 5.26 % and 0, respectively), and 85 % of the calculation time is saved. The results show uncertain parameters related to loads, section size and elastic modulus should be paid attention to in bridge crane structural reliability design.

A novel structural reliability method based on active Kriging and weighted sampling

Wenzhao Li,Ruigang Yang,Qisong Qi,Qing Dong,Guangli Zhao 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

With complex limit state functions and small failure probability, the analysis of engineering structure reliability is a challenging problem. Most of the traditional methods require a lot of calculation time, which results in delaying the progress of solving engineering. To overcome this issue, a new structural reliability analysis method aiming to select a set of better initial design of experiment (DoE) is proposed in this study. The proposed method combines a weighted sampling based on sample probability and a novel selection strategy to select DoE and conduct active learning. Weighted sampling based on sample probability density makes the DoE uniformly distributed in the sampling space. The novel selection strategy is proposed to make selected DoE near limit state surface (LSS) and has better predictive ability. Numerical examples and engineering examples show that this method can perform energy efficiency analysis in important areas. The results show that the method is accurate and efficient in solving low failure probability and nonlinearity problems.

Top online luxury apparel and accessories retailers: what are they doing right?

Wenzhao Mu,Sharron J. Lennon,Wenqiao Liu 한국의류학회 2020 Fashion and Textiles Vol.7 No.1

Many luxury firms have successfully adopted online sales and online sales growth has outperformed offline sales growth. As online luxury sales continue to grow, service expectations in digital and instore channels are also expected to grow. To add to the research literature, the top performing 46 luxury apparel and accessories websites identified in the Luxury e-Commerce Report from Internet Retailer were content analyzed to determine the state of the art in top performing luxury retail websites in providing needed information (international customer service attributes). Those top performing websites were then compared to 44 randomly selected similar websites on the same attributes to determine how the two groups of websites compared in terms of international customer service attributes. Although top performing luxury retail websites are providing important customer service information that facilitates online purchasing, there is room for improvement. In comparing the two groups of online luxury merchants, each group had strengths and weaknesses. Overall, merchants performed at a suboptimal level on provision of many customer service attributes, need improvement on others, and performed well on a few attributes. These luxury fashion online retailers are at an early stage in providing important customer service attributes on their websites.

Risk Management of Small & Medium-Sized Enterprises in Financial Crisis

Wang Wenzhao,Wu Wenbing,Wang Wencheng 인하대학교 정석물류통상연구원 2009 인하대학교 정석물류통상연구원 학술대회 Vol.2009 No.10

Small & medium-sized enterprises, which take up 99% of the total number of the enterprises in our nation, have been playing a very important role in keeping sustainable development of our national economy. Among them, the export-oriented processing trade enterprises are severely influenced by the financial crisis triggered from USA, which reveals that our small & medium-sized enterprises" weakness in risk analyzing, risk control and management. This article takes small & medium-sized enterprises in Pearl River Delta Region and Ningbo as examples to analyze the risk these enterprises face in financial crisis and to propose some related solutions.

사칠이기논변을 중심으로 본 고봉 기대승의 본성론 연구

리우 원자오(Wenzhao Liu) 한국외국어대학교 철학문화연구소 2022 철학과 문화 Vol.47 No.-

퇴계 이황과 고봉 기대승의 사칠이기 논변에서 제기된 문제는 매우 많았고, 후대 여러 학자들의 토론을 야기했다. 이 글은 고봉 기대승이 논변 과정에서 표명한 사상을 중점적으로 고찰하면서, 분석과 귀납의 방법을 통해 고봉만의 체계적이고 특색있는 본성론을 형성할 수 있음을 밝혔다. 고봉의 본성론에는 구체적으로 다음 4가지의 문제가 포함되어 있다: (1) 본성의 본체, (2) 심성정(心性情)의 관계, (3) 천명지성과 기질지성, (4) 본성과 사단. 앞의 두 가지는 본체론에 속하고 뒤의 두 가지는 공부론에 속하는 것이다. 고봉의 본성론은 주자학을 기초로 삼아 사칠이기 논변에서 형성된 사상으로, 그가 기질지성을 “물 속의 달(水中月)”로 비유한 것과 “사단부중절(四端不中節)”에 대해 논술한 것은 상당히 참신한 의미가 있는 것이다. 이 글에서는 고봉의 사칠이기 변론을 새롭게 이해하는 사유방법을 제시하였다. Toegye Yi Hwang and Gobong Gi Daeseung's Debate on Four Seven and Li Qi has a lot of questions, which has opened the discussion of many scholars in later generations. This paper focuses on the ideas expressed by Gobong in the debate, and finds that it can form a systematic and characteristic theory of nature through the analytic and inductive methods. Gobong's theory of nature contains four problems: The substance of nature(性之本體), the relationship between Mind, Nature and Emotion( 心性情關係), the nature of heaven mandate and the nature of physical body(天命之性與氣質之性), and nature and Four Sprouts(性與四端). The former two belong to the realm of metaphysics, while the latter two belong to the realm of self-cultivation. Gobong's theory of nature is a thought formed in Debate on Four Seven and Li Qi, and based on the study of Zhu Zi(朱子). Among them, the metaphor of "the moon in the water(水中月)" and the description of "Inappropriate Four Sprouts(四端不中節)” have new meanings. This paper provides a new way to understand the thoughts in Debate on Four Seven and Li Qi. 李退溪、奇高峰的“四七理氣之辯”討論問題衆多,引起后世諸多學者的討論。本文側重考察高峰在論辯中所體現出的思想,通過分析和歸納的方法,發現其可以形成一個系統而有自身特色的性論。高峰性論具體包含四個問題:性之本體,心性情關係,天命之性與氣質之性,性與四端;前兩者屬於本體論,后兩者屬於工夫論。高峰性論是以朱子學爲基礎,在“四七理氣之辯”中所形成的思想,其中氣質之性的“水中月”比喻和“四端不中節”的論述都頗具新意。本文提供了一種理解“四七理氣之辯”的新思路。

Flexibility and Thermal Storage Properties of Polyurethane Adhesive Supported Phase Change Composites Based on Polyurethane Phase Change Materials

Jiankun Dong,Wenzhao Shi,Jinshu Liu,Shaofeng Lu,Hongjuan Zhou,Shanshan Cui,Manyan Zhang,Guoxin Su 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

Polyurethane phase change materials (PUPCMs) have been extensively applied in smart textiles and wearable electronic devices because of their excellent energy storage capacity. To realize the flexibility of PUPCMs for certain deformation and compact contact with objects, suitable support structures have been chosen to prepare polyurethane phase change composites (PUFPCCs) with energy storage capacity and device-level flexibility. In this work, PUPCM was prepared by the prepolymer method with polyethylene glycol (PEG) as the soft segment, 4,4-dicyclohexylmethane diisocyanate (HMDI) and 1,2-hexanediol as the hard segment. And polyurethane-based adhesives (PUA) were chosen to provide a support structure for PUFPCCs by physically blending and casting with prepared PUPCM. PUFPCCs showed good flexibility attributed to the film-forming performance of polyurethane-based adhesive in the composites. The chemical structure, crystallization properties, phase transformation properties and thermal stability of the prepared PUPCM and PUFPCCs were investigated via Fourier transform infrared spectroscopy (FT-IR), 1H NMR spectroscopy, X-ray diffraction (XRD), polarizing optical microscope (POM), differential scanning calorimetry (DSC) and thermogravimetric (TG) analysis respectively. The phase change temperature of PUFPCCs ranged from 36 to 40 ℃. The maximum enthalpy value of PUFPCCs was up to 40 J/g for daily application. Moreover, the thermal stability of PUPCM was improved attribute to the support structure of PUA in PUFPCCs. Therefore, the prepared PUFPCCs have great potential for application in flexible wearable devices due to their excellent flexibility, suitable phase transition temperature close to human body temperature, high enthalpy value and improved thermal stability.

Effect of Mulching on Dryland Soil Water, Winter Wheat Yield, and Water Use Efficiency

Jun Wang,Wenzhao Liu,Upendra M. Sainju 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Public Administration in China—Evolution and Current Challenge

Wei Liu,Wenzhao Li 서울대학교행정대학원 2013 Asian Journal of Political Science Vol.21 No.1

Taking an ecological approach, this article examines the resumption, formation, and development of public administration (PA) as a discipline in China. Through content analysis and process tracing, we argue that the social contexts during China's transition period and existing knowledge, both endogenous and exogenous, are major forces shaping the nature of the discipline and pushing its development. We also point out that Chinese PA now is facing challenges, calling for deeper localization and closer integration into global scholarship.