Synthesis and Characterization of Poly 〔 ( Styrene - p - Bromostyrene ) - b - Methyl Methacrylate 〕 by Telomerization

유지강,서길수,최삼권 한국고분자학회 1979 폴리머 Vol.3 No.6

Poly(Ester Oxadizaol)과 Poly(Ester Hydrazide)의 합성과 특성

유지강,이용혁,이법원 한국고분자학회 1997 한국고분자학회 학술대회 연구논문 초록집 Vol.1997 No.10

분자구조적으로 설계된 폴리옥사다이아졸의 합성 및 성질

유지강,이법원,김선일 조선대학교 생산기술연구소 2000 生産技術硏究 Vol.22 No.1

Polyhydrazide was prepared by solution polycondensation of an aromatic dihydrazide, bis (2-hydroxy ethyl terephthalic mono-hydrazido) fumarate (BHF) and an isophthaloyl chloride in N-methyl pyrrolidinone (NMP) in the presence of pyridine as an acid acceptor. The polymer was converted into oxadiazole-containing polymer, POD by chemical cyclodehydration with thionyl chloride. In this work, isophthaloyl chloride was introduced t o enhance solubility. The POD can be dissolved in aprotic polar solvents such as NMP and organic solvents such as chloroform/trifluoroacetic acid (TFA) mixed solvent The POD having molecularly designed structure of the fixed conjugation length shows photoluminescence(PL) at about 440 nm which corresponds t o blue color, and Δλ l/2 is about 80 nm which means it emits relatively pure light.

가공성이 향상된 하이드라자이드 및 옥사다이아졸 고분자의 합성

유지강,이용혁 조선대학교 생산기술연구소 1998 生産技術硏究 Vol.20 No.2

Polyhydrazide는 방향성의 dihydrazide 단량체와 유연격자가 포함된 bisbenzoyl chloride 단량체를 저온에서 dimethylacetamide를 중합용매로, pyridine을 산제거제로 사용하여 용액중합으로 합성하였다. Polyoxadiazole은 polyhydrazide를 thionyl chloride로 처리하는 화학적 고리탈수반응으로 합성하였다. Polyoxadiazole의 희박용액점성도는 0.68㎗/g이었다. 합성된 고분자는 비양성자성 극성용매에의 용해도가 향상되었으며 융점이 271℃로서 용융가공이 가능함을 확인하였다. Polyhydrazide was prepared by low temperature solution polymerization of an aromatic dihydrazide and a bisbenzoyl chloride having flexible spacer in dimethylacetamide containing pyridine as an acid acceptor. The polymer was converted into polyoxadiazole by chemical cyclodehydration with thionyl chloride. The inherent viscosity of polyoxadiazole was 0.68㎗/g. The resulting polymer showed enhanced solubility in aprotic polar solvents and melt-processibility as its melting temperature is 271℃.

习近平 “新时代”下的中国经济 “软着陆”相关因素分析

유지강,서창배 중국지역학회 2017 중국지역연구 Vol.4 No.2

Since the subprime mortgage crisis in 2008, the global economy has changed in many ways. In particular, the global economy is facing serious adjustments with the normalization of new normal and international economic fluctuations are intensifying. This is changing the positive factors and the market environment that led to the rapid economic growth of China, including exports and investment. This is affecting not only the international recession but also the growth of the Chinese economy. Moreover, the Chinese economy has been exposed to many problems accumulated in the process of rapid economic growth, and has entered into a new stage in Xinchangtai(新常态) due to the complex action between the problems. Accordingly, Chinese domestic and international public opinion and academic research related to the Chinese economy are focused on whether it is hard landing or soft landing. In particular, whenever there is some change in the Chinese economy, the possibility of a hard landing is getting stronger with a pessimistic outlook. This debate can be seen as a result of the difference from the Western economic theory. This study analyzed the implications of the meaning and characteristics of “Socialism with Chinese Characteristics for New Era(新时代中国特色社会主义)” which was recently announced by Xi Jinping(习近平), the General Secretary of China’s Communist Party, on China’s economic development in connection with “Xin Chang Tai(新 常态)”. We also analyzed the impact of reforms in China on new growth potentials. In addition, the “B&R(一带一路) Initiative”, which the Chinese government is being pursued as major government project, and the “Go globally (走出去)” strategy will have a positive impact on China’s economy. These factors are expected to make possibility of soft landing in conjunction with sustainable growth of the Chinese economy, deepening reform, and creation of new engine for economic growth. In particular, we expect the “Go globally” strategy based on the B&R initiative to lead to the internationalization and expansion of the Chinese economy. In summary, the Chinese economy is expected to have a higher chance for soft landing. 2008년 서브프라임 모기지(subprime mortgage) 사태 이후 세계경제는 많은 부분에서 변화하고 있다. 특히 세계경제는 뉴노멀(new normal)의 일상화와 함께심각한 조정기에 직면하며 국제적인 경기 변동이 심화하고 있다. 이러한 변화는 수출, 투자 등 과거 중국경제의 고성장을 이끌던 긍정적 요인들과 시장환경을 변화시킴으로써 국제적인 경기침체는 물론이고 중국경제의 성장 하락에도영향을 미치고 있다. 더욱이 중국경제는 급속한 경제성장과정 속에 축적된 많은 문제점들이 드러내며 그 문제들 간의 복합적인 작용으로 인해 신창타이(新 常态), 즉 새로운 조정기에 진입하고 있다. 이에 따라 중국경제와 관련한 국내외적인 여론 및 학술연구의 초점이 경착륙 또는 연착륙 가능성 여부에 맞추어져 있다. 특히 중국경제가 일부 변동이 생길 때마다 비관적 전망을 중심으로경착륙 가능성이 크게 대두되고 있다. 이러한 논쟁은 일정부분 서방 경제이론과의 차이에서 비롯된 것이라고 볼 수 있다. 이에 본 연구는 시진핑(习近平) 중국공산당 총서기가 최근 밝힌 ‘신시대 중국 특색 사회주의(新时代中国特色 社会主义)’에 담긴 의미와 특징이 신창타이와 연계되어 중국경제발전에 미칠영향을 분석하였다. 또한 중국 내부의 개혁이 새로운 성장 잠재력 요인들과 연계되어 나타날 수 있는 영향을 분석하였다. 이와 함께 중국정부가 핵심 국정과제로 추진 중인 ‘일대일로(B&R) 이니셔티브’의 안정적인 추진과 해외진출(走出 去)전략이 중국경제에 긍정적인 영향을 미칠 것으로 분석하였다. 이러한 요인들이 중국경제의 지속 가능한 성장, 개혁의 심화, 새로운 성장 동력의 창출 등과 연계되어 연착륙이 가능하도록 해줄 것으로 전망한다. 특히 B&R 이니셔티브를 바탕으로 한 해외진출전략을 통해 중국경제의 국제화 및 영역 확대 등으로 이어질 것으로 예상한다. 이를 종합해볼 때, 중국경제는 연착륙 가능성이 더높은 것으로 전망된다.

카르복시 폴리술폰 아이오노머의 기계적 성질

유지강,이용혁,김희석,김준섭,박기주,D. Nguyen,A. Eisenberg 조선대학교 생산기술연구소 1997 生産技術硏究 Vol.19 No.1

The dynamic mechanical properties of carboxylated polysulfone ionomers were studied by using DMTA. It was found that at 25 mol% of ions, the ionomer shows two glass transitions: one at ca. 200 ℃ and the other at ca. 235 ℃. It was also found that with increasing an ion content to ca. 37 mol%, a matrix T_(g) shifts to ca. 210 ℃, but a cluster T_(g) remains at the same temperature; however, the sizes of tan δ peaks for each transitions do not change with the ion content. This result means that even at those high ion contents, there is sufficient amount of a unclustered material in the samples, and the increase in the ion content does not increase the volume fraction of a cluster phase. In addition, the difference in two T_(g)s of this ionomer system was found to be ca. 40 ℃, which is smaller than that in poly(styrene-co-methacrylate) ionomer system. This finding implies that in the polysulfone ionomers weak ionic interactions in a multiplet resulting from steric hindrance due to the bulkiness of benzene ring to which the ionic group is attached and the tension on polymer chains surrounding the multiplet due to chain rigidity affect the size and stability of the multiplet significantly.

浅析≪论语≫中“礼乐”之“乐”

?志?(유지강),金昌?(김창경) 동북아시아문화학회 2016 동북아시아문화학회 국제학술대회 발표자료집 Vol.2016 No.10

This article defined the “YUE” is “YUE” in the analects of Confucius “LI and YUE Culture”. Concept of “benevolence” is the core of Confucius philosophy is ontology of Confucian philosophy system, “The LI” and “The YUE” is the path to “benevolence”. The “LI” and “YUE” argue each other dependent, is the core of Confucius thought of “benevolence” externalizing reflected, is an important means of political ethics; In the aspect of social education and personal accomplishment, “YUE” is the unity of the moral and art, is a person how to become a “gentleman”, achieve the highest state of harmonious personality; Confucius" interpretation of the thought of “YUE”, formed the good harmonious humanistic spirit, laid the gene of Chinese LI and YUE Culture, has profound influence on the development of China"s cultural history.

자유 라디칼 Telomerization 에 의한 Poly 〔 ( Styrene - p - Bromostyrene ) - b - Methyl Methacrylate 〕 의 합성 및 확인

유지강(Ji Kang Yoo),서길수(Gil Soo Sur),최삼권(Sam Kwon Choi) 한국고분자학회 1980 폴리머 Vol.4 No.5

사과나무에서 가지검은마름병 억제를 위한 효율적 가지치기

한규석,유지강,이한별,오창식,예미지,이종호,박덕환 한국식물병리학회 2016 식물병연구 Vol.22 No.4

Black shoot blight disease caused by Erwinia pyrifoliae have damaged economic loss to apple and pear growers until now since it was firstly reported in 1995 in Korea. This study was performed to reduce economic loss by mandatory eradication of all infected trees in case of more 10% disease incidence per orchard as official control. It also aims to set up effective management protocol for this disease by examining how far bacterial pathogen is present from the border of symptomatic and asymptomatic regions in infected apple twigs. Colony-PCR using isolated bacterial cells instead of genomic DNA was used to identify bacterial pathogen, EpSPF/EpSPR primer designed in enterobacterial repetitive intergenic consensus (ERIC) region was selected as specific for E. pyrifoliae. As results of monitoring of this disease during April to October in 2014–2015 by colony-PCR, occurrence of this disease was frequent from mid-May to early-July, when daily average temperature was around 25oC. Moreover, bacterial cells were continuously detected only in symptomatic regions and also asymptomatic regions of less than 20 cm from symptomatic regions. Therefore, we concluded that pruning of infected twigs at the region of more than 20 cm from symptomatic regions might be effective to manage black shoot blight disease in apple trees.

Synthesis and Evaluation of Antitumor Activity of Novel 1,4-Naphthoquinone Derivatives (IV)

김복희,유지강,박시현,정재경,조훈,정용석 대한약학회 2006 Archives of Pharmacal Research Vol.29 No.2

1,4-Naphthoquinones are widely distributed in nature and many clinically important antitumor drugs containing a quinone moiety, such as anthracyclines, mitoxantrones and saintopin, show excellent anticancer activity. In this study, 2- or 6-substituted 5,8-dimethoxy-1,4-naphthoquinone (DMNQ) and 5,8-dihydroxy-1,4-naphthoquinone (DHNQ) derivatives were synthesized, and their cytotoxic activity against L1210 and P388 cancer cells was examined. Their antitumor activity was also assessed in mice bearing S-180 cells in the peritoneal cavity. In comparison with the DMNQ derivatives, the DHNQ derivatives exhibited more potent bioactivities than the DMNQ derivatives against both L1210 and P388 cells in vitro and S-180 cells in vivo. The ED50 values of the DHNQ derivatives against P388 cells were in the range of 0.18- 1.81 μg/mL whereas those of the DMNQ derivatives were in the range of 0.26-40.41 μg/mL. The T/C (%) values of the DHNQ derivatives, 8, 17, 18, 19, and 20, were found to be comparable to or even better than that of adriamycin. It was also observed that the 2-substituted derivatives (8, 19, 20) showed better antitumor activity than the 6-substituted derivatives (7, 17, 18) in the mice bearing S-180 cells in the peritoneal cavity.