Investment Climate Analysis of China and South Korea: Based on Grading Method

Jing LI(Jing LI),Xin Yu XU(Xin Yu XU),Jie XU(Jie XU),Shuai SU(Shuai SU),Fan ZHANG(Fan ZHANG) 한국4차산업학회 2022 4차산업연구 Vol.2 No.2

Purpose - This study analyzes the investment environment of South Korea by using the rating scale of Robert B Stobaugh, Jr, and draws conclusion implication. Research design, data, and methodology - The study conducted a survey on according to the political stability, capital repatriation, foreign ownership allowed, discrimination and controls, foreign vs domestic businesses, currency stability, willingness to grant tariff protection, availability of local capital, and annual inflation for last 5 years. The score of these eight aspects will be given based on the current situation in South Korea and the sum of the scores will be calculated. Result - China-Korea economic and trade relations are in a stage of transformation and upgrading, and the level of economic and trade cooperation in various fields is reaching a new level. It is hoped that Chinese enterprises will grasp business opportunities, strengthen research and analysis of the Korea market and achieve mutually beneficial cooperation. Conclusion - The investment environment of South Korea is superior according to the political stability, capital repatriation, foreign ownership allowed, discrimination and controls, foreign vs domestic businesses, currency stability, willingness to grant tariff protection, availability of local capital, and annual inflation for last 5 years.

Catalytic activity of Cu/MgO in liquid phase oxidation of cumene

Shuai Xu,Jie Zhang,Biaohua Chen,Chongpin Huang 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.6

Cumene was oxidized with air as the oxidant and Cu/MgO as the catalyst. Cu/MgO with different compositions was prepared by co-precipitation and then characterized by X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR) and X-ray photoelectron spectroscopy (XPS). The characterization results showed that CuO dispersed on MgO well in the cases that the Cu content in Cu/MgO was 1% by molar. In this catalytic system, MgO did not only act as the supporter, but also as the catalyst to activate the tertiary C-H of cumene. The conversion of cumene was increased by using CuO as the promoter on MgO catalyst. The cumene conversion and cumene hydroperoxide (CHP) selectivity were in a trade-off relationship because cumene oxidation was subject to the decomposition of CHP. Thus, the effects of the operating variables were investigated and the relevant mechanism was discussed.

Catalytic oxidation of 1,3-diisopropylbenzene using imidazolium ionic liquid as catalyst

Shuai Xu,Jie Zhang,Jia Liu,Biaohua Chen,Chongpin Huang 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.4

Peroxidation of alkylaromatics is the key step in the synthesis of phenols. Different imidazolium ionic liquids were investigated for the oxidation of cumene. The selectivity of cumene hydroperoxide (CHP) increased with different ionic liquids in the order [C4mim]Cl<[C4mim]Br<[C4mim]BF4<[C4mim]OH. This finding could be interpreted as being due to the partial decomposition of CHP by the acidic proton of the imidazolium cation. Thus [C4mim]OH was chosen as the catalyst for the oxidation of 1,3-diisopropylbenzene to corresponding hydroperoxides and its derivatives. The catalytic performance of [C4mim]OH was also better than that of the traditional catalyst NaOH. Furthermore, the effects of the operating variables were investigated and the mechanism was discussed.

Effect of In Situ Thermal Stretching during Oxidative Stabilization on the Orientation of Cyclized Ladder Structure and Its Carbon Fiber

Shuai Wu,Ai-jun Gao,Liang-hua Xu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.6

The effect of in situ thermal stretching during oxidative stabilization on the orientation of cyclized ladder structure was investigated. Based on the structure evolution of PAN fibers with the increasing stabilization temperatures, the stabilization process was classified into three different stages, namely before the onset of cyclization, during cyclization in amorphous region, and during cyclization in crystalline region. The polyacrylonitrile (PAN) precursor fibers were stretched at the three stages with stretching ratios from 0 % to 8 % during continuous stabilization process. The results show that the orientation degree of cyclized ladder structure increases with the increase of stretching ratio at the three stages and the maximum orientation efficiency of cyclized ladder structure is obtained when PAN fibers are stretched at the stage of during cyclization in crystalline region. The orientation of resulting carbon fibers strongly depends on the orientation degree of cyclized ladder structure. The orientation efficiency of turbostratic graphite crystallite also agrees well with that of cyclized ladder structure. Meanwhile, the orientation efficiency of turbostratic graphite crystallite is higher than that of cyclized ladder structure and the difference values between orientation efficiency of the two structures decrease firstly then increase with the increase of degree of cyclization.

Fungal diversity in deep-sea sediments from Magellan seamounts environment of the western Pacific revealed by high-throughput Illumina sequencing

Shuai Yang,Wei Xu,Yuanhao Gao,Xiaoyao Chen,Zhu-Hua Luo 한국미생물학회 2020 The journal of microbiology Vol.58 No.10

There are lots of seamounts globally whose primary production is disproportionally greater than the surrounding areas. Compared to other deep-sea environments, however, the seamounts environment is relatively less explored for fungal diversity. In the present study, we explored the fungal community structure in deep-sea sediments from four different stations of the Magellan seamounts environment by using high-throughput sequencing of the ITS1 region. A total of 1,897,618 ITS1 sequences were obtained. Among these sequences, fungal ITS1 sequences could be clustered into 1,662 OTUs. The majority of these sequences belonged to Ascomycota. In the genera level, the most abundant genus was Mortierella (4.79%), which was reported as a common fungal genus in soil and marine sediments, followed by Umbelopsis (3.80%), Cladosporium (2.98%), Saccharomycopsis (2.53%), Aspergillus (2.42%), Hortaea (2.36%), Saitozyma (2.20%), Trichoderma (2.12%), Penicillium (2.11%), Russula (1.86%), and Verticillium (1.40%). Most of these recovered genera belong to Ascomycota. The Bray-Curtis analysis showed that there was 37 to 85% dissimilarity of fungal communities between each two sediment samples. The Principal coordinates analysis clearly showed variations in the fungal community among different sediment samples. These results suggested that there was a difference in fungal community structures not only among four different sampling stations but also for different layers at the same station. The depth and geographical distance significantly affect the fungal community, and the effect of depth and geographical distance on the structure of the fungal community in the Magellan seamounts is basically same. Most of the fungi were more or less related to plants, these plant parasitic/symbiotic/endophytic fungi constitute a unique type of seamounts environmental fungal ecology, different from other marine ecosystems.

Electrostatic self‑assembly cellulose nanofibers/MXene/nickel chains for highly stable and efficient seawater evaporation and purification

Shuai Yang,Cai Shi,Keqi Qu,Zhe Sun,Handong Li,Benbin Xu,Zhanhua Huang,Zhanhu Guo 한국탄소학회 2023 Carbon Letters Vol.33 No.7

Seawater evaporation and purification powered by solar energy are considered as a promising approach to alleviate the global freshwater crisis, and the development of photothermal materials with high efficiency is imminent. In this study, cellulose nanofiber (CNF)/MXene/Ni chain (CMN) aerogels were successfully synthesized by electrostatic force and hydrogen bond interaction force. CMN10 achieved a favorable evaporation rate as high as 1.85 kg m? 2 h? 1 in pure water, and the corresponding evaporation efficiency could be up to 96.04%. Even if it is applied to seawater with multiple interference factors, its evaporation rate can still be 1.81 kg m? 2 h? 1. The superior seawater evaporation activity origins from the promoted separation of photoexcited charges and photothermal conversion by the synergy of Ni chain and MXene, as well as the water transport channel supported by the 3D structure frame of CNF. Most importantly, CMN aerogel can maintain water vapor evaporation rates above 1.73 kg m? 2 h? 1 under extreme conditions such as acidic (pH 2) and alkaline (pH 12) conditions. In addition, various major ions, heavy metals and organic pollutants in seawater can be rejected by CMN10 during desalination, and the rejection rates can reach more than 99.69%, ensuring the purity of water resources after treatment. This work shows the great potential of CMN aerogel as a high-efficiency solar evaporator and low-cost photothermal conversion material. Cellulose nanofiber (CNF)/MXene/Ni chain (CMN) aerogels demonstrated high evaporation of water from sea water.

Non-Fixed Investment in Voluntary Public Goods Games

Shuai Wang,Zhaojin Xu,Lianzhong Zhang 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.9

In this work, we introduce a non-fixed investment ratio to the public goods games in which players can determine whether or not to participate and how much money to invest into the common pool, and with it a new mechanism has been established. We explicitly demonstrate a different rockscissors- paper dynamics which is a consequence of this model. Meanwhile, it is shown how the mechanism of non-fixed investment ratio in uences the players' decision. In addition, we found that the length of memory has an important effect on the average payoff of the population by this introduction.

Adaptive V1-MT model for motion perception

( Shuai Li ),( Xiaoguang Fan ),( Yuelei Xu ),( Jinke Huang ) 한국인터넷정보학회 2019 KSII Transactions on Internet and Information Syst Vol.13 No.1

Motion perception has been tremendously improved in neuroscience and computer vision. The baseline motion perception model is mediated by the dorsal visual pathway involving the cortex areas the primary visual cortex (V1) and the middle temporal (V5 or MT) visual area. However, few works have been done on the extension of neural models to improve the efficacy and robustness of motion perception of real sequences. To overcome shortcomings in situations, such as varying illumination and large displacement, an adaptive V1-MT motion perception (Ad-V1MTMP) algorithm enriched to deal with real sequences is proposed and analyzed. First, the total variation semi-norm model based on Gabor functions (TV-Gabor) for structure-texture decomposition is performed to manage the illumination and color changes. And then, we study the impact of image local context, which is processed in extra-striate visual areas II (V2), on spatial motion integration by MT neurons, and propose a V1-V2 method to extract the image contrast information at a given location. Furthermore, we take feedback inputs from V2 into account during the polling stage. To use the algorithm on natural scenes, finally, multi-scale approach has been used to handle the frequency range, and adaptive pyramidal decomposition and decomposed spatio-temporal filters have been used to diminish computational cost. Theoretical analysis and experimental results suggest the new Ad-V1MTMP algorithm which mimics human primary motion pathway has universal, effective and robust performance.

Molecular Dynamics Study of Polyisoprene-polystyrene Composites: Spatial Complementary Behaviour

Xu Liu,Shuai Leng,Qianqian Zhang,Yongbing Xue 한국고분자학회 2020 폴리머 Vol.44 No.6

Various additives have been applied to adjust the properties of rubber in the tire industry. As an important environmental waste, plastic is a potential additive to be added to rubber to blend aiming at forming abrasive and deformation resistance elastomers. However, the molecular details remain unclear, especially for their assembly structure. Using all-atom molecular dynamics simulations, we have studied the assembly structures and processes of polyisoprene and polystyrene complex, focusing on the spatial complementary behavior. The simulation results indicate that polyisoprene and polystyrene can form tight entangled structure. The polyisoprene can adjust their conformations to fill up the cavity generated from polystyrene self-aggregation. The formed cross-linked and spatial polystyrene complementary structures can improve the plasticity and abrasive resistance, which is superiority in tire design. Our results provide an important understanding of the rubber application and tire industry and give a possible idea to deal with abandoned plastics.

Influence of Particle Shape on the Density and Compressive Performance of Calcareous Sand

Shuai Wang,Xue-Wen Lei,Qing-Shan Meng,Jie-Li Xu,Ling-Feng Xie,Yu-Jie Li 대한토목학회 2020 KSCE Journal of Civil Engineering Vol.24 No.1

Particle shape influence the bearing capacity of calcareous sand foundations in island reef engineering. An improved Computer Image Analysis method that combined with mathematical statistics was proposed to categorize and sort different shapes of calcareous sand particles within the size range of 5 – 10 mm. Three single-shape calcareous sand specimens (granular ﾠ ﾠshape, dendritic shape, long strip shape) were obtained. A new self-developed vibration device was used measuring the maximum density of calcareous, the shape and content as the variables in the orthogonal test. On this basis, the lateral compression tests were carried out to assess the influence of particle shape on the density, compressive performance of calcareous sand. Test results showed that better discriminability was achieved by taking mean flatness (EL/B) as the quantification parameter of the particle shapes. The average flatness EL/B of specimens is approximately normally distributed in the statistical results. The shape and content of sand particles had an obvious influence on the density of calcareous sand. The compressive properties of calcareous sands with different particle shapes have obvious differences. After loaded, the particle size distribution of specimen improved, the average flatness EL/B of the granular-shaped specimens increased, while that of the dendritic-shaped and the long-strip-shaped specimens decreased, the average flatness EL/B of the specimens tended to be uniform. The relative fracture rate Br and the load value Pmax satisfied the exponential function fitting relationship. Therefore, it can be argued that particle shape should be taken into consideration when optimizing the foundation design in island reef engineering to achieve better compressive performance of the foundation.