http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
절화 카네이션의 급속 개화에 KI 및 NaBH₄가 미치는 영향
이인국,임정현,손기철 건국대학교 생명과학연구원 1994 생명과학지 Vol.1 No.-
어버이날이나 스승의 날과 같은 절화의 수요가 급증하는 시기에는 절화 카네이션의 수명보다는 오히려 화기의 급속열림의 필요성이 매우 중요하다. 왜냐하면, 대부분이 조기 채화되어 불개화되는 율이 높고, 목적상 일회적으로 사용되어지기 때문이다. 급속화기 열림제를 위하여 조사한바, 기본 용액(당 2%+8HQS 200ppm)에 NaBH?와 KI는 1mM의 농도에서 단독처리나 복합처리 모두 화기급속열림에 매우 효과적인 것으로 나타났으며, 1∼2일 후에 화경을 두 배로 증가시켰다. 그러나 이러한 급속화기 열림제는 고농도일 경우 절화수명은 오히려 단축시키는 것으로 나타났다. Rapid flower opening was much more important than flower longevity when cut carnation was in great demand such as Mother's or Teacher's day because carnations were mostly harvested at pre-open stage. Combination of 1mM NaBH? or/and 1mM KI together with a basal solution (surose 3%+8HQS 200ppm) have been found to be very effective in the rapid flower opening of cut carnation cv. Desio where they showed two fold increased flower diameter during 1 or 2 days after treatment. However, it was found that the higher concentration was, the shorter flower longevity was because of toxicity.
Neuroprotective effects of herbal mixture HT070 on global cerebral ischemia in rats
( Jung Bin Song ),( Dong Hun Lee ),( Young-sik Kim ),( Hyun Jeong Lee ),( Seung Gyeong Lee ),( Dong Kuk Kim ),( Shin Ho Kang ),( Yong Kook Shin ),( Ho-young Choi ),( Ho Cheol Kim ) 대한본초학회 2016 大韓本草學會誌 Vol.31 No.4
Objectives : HT070 is a mixture of herbal extracts from root of Scutellaria baicalensis and stem bark of Eleutherococcus senticosus, which have long been used for stroke therapy in traditional Korean Medicine. The purpose of this study was to investigate the neuroprotective effects of HT070 on global cerebral ischemia and its potential mechanisms. Methods : Transient global cerebral ischemia was produced by 10 min of four-vessel occlusion (4-VO) in male Wistar rats. HT070 was administered orally at a dosage of 200 mg/kg twice at 0 and 90 min after reperfusion. Hippocampal neuronal damage was measured 7 days after reperfusion. To explore the potential mechanisms, we used hydrogen peroxide (H2O2)-induced rat pheochromocytoma (PC12) cells as an in vitro model. PC12 cells were pretreated with HT070 for 1 h and then exposed to 100 μM H2O2 for 6 h in the presence of HT070. Cell viability was measured by MTT assay and the mRNA expression of Bax, Bcl-2, iNOS and COX-2 were measured by quantitative RT-PCR. Results : Oral administration of HT070 at a dose of 200 mg/kg significantly reduced neuronal death in the hippocampal CA1 region by 13.4% as compared to the vehicle-treated group. HT070 increased cell viability, reversed the down-regulated Bcl-2 mRNA level, and suppressed the up-regulated mRNA expressions of Bax, iNOS, and COX-2 in H2O2-treated PC12 cells. Conclusions : HT070 protects against delayed neuronal death after global cerebral ischemia and its neuroprotection properties might be attributed to the inhibition of mitochondrial apoptosis and ROS-generating enzymes.
Current Control for an AFE Rectifier Using Space Vector PWM
Cheol-Hwan Jeon,Jae-Jung Hur,Kyoung-Kuk Yoon,Heui-Han Yoo,Sung-Hwan Kim 해양환경안전학회 2019 海洋環境安全學會誌 Vol.25 No.4
해양산업분야에서는 극심한 대기오염으로 인하여 전기추진선박에 대한 관심이 높아지고 있다. 이로 인해 선내 전력품질의 저하를 개선하기 위한 연구가 활발히 진행되고 있다. 기존 DFE 정류기의 입력전류 고조파 함유량을 완화시키기 위해 수동형필터, 노치필터, 능동형필터 등을 이용한 다양한 방법이 등장하였다. 그 중에서도 능동필터의 일종인 AFE(Active Front End) 정류장치가 우수한 기술로써 평가받고 있다. 본 논문에서는 공간벡터변조에 의한 AFE정류장치의 전류제어방식을 제안하였다. 기존의 히스테리시스 방식, 삼각파 변조 방식 및 공간벡터변조방식을 PSIM을 사용해 시뮬레이션을 수행하여 비교, 분석하였고, 그 결과 공간벡터변조방식이 구조가 간단하고 성능이 가장 우수함을 확인하였다. Electric propulsion ships are gaining widespread interest in the marine industry owing to extreme air pollution concerns. Consequently, several studies are actively being conducted for improving the power quality. Various methods have been developed that incorporate passive filters, notch filters, and active filters for reducing the harmonic content in the input current of a conventional diode front end rectifier. Among such filters, the active front end (AFE) rectifier is considered as an excellent technology. In this paper, current control for an AFE rectifier employing space vector PWM (Pulse Width Modulation) is proposed. Conventional current control methods for the AFE rectifier, hysteresis, SPWM (Sinusoidal Pulse Width Modulation), and SVPWM (Space Vector Pulse Width Modulation) were simulated by employing the PSIM software tool for analysis and comparisons. The results corroborate that SVPWM has the simplest structure and provides the best performance.
Fabrication of A Nanoscale Tip for Scanning Force Microscope
Jung, Mi-Young,Kim, Dae-Wook,Choi, Seong Soo,Kim, Yong-Suk,Kim, Cheol-Kyu,Yang, Kuk 선문대학교 첨단과학기술연구소 1996 첨단과학기술연구소 논문집 Vol.1 No.1
SFM 의 초미세 검침의 제작을 하였다. 실리콘(100) 기판위에 보론 불순물을 확산시켜 10^(20)/㎤ 이상으로 5㎛깊이로 되게하였다. 산화막 및 패턴, KOH 용액의 보론의 농도에 따른 식각특징 등을 통한 일반적인 미세가공방법을 통하여 미세 cantilver의 제작을 하였고 검침의 형상은 기판의 앞면 에 pattering 을 하고 반응성 기체식각방법및 sharpening oxidation 및 oxide strip을 이용 제작하였다. photoresist mask 막을 사용하기보다는 실리콘 산화막을 mask로 이용하여 검침의 반경을 20㎚이하로 만드는데 성공하였다. Fabrication of a nanoscale(20>) tip for scanning force microscope(SFM) was successfully performed. Initially, a boron impurities with about 10^(20)/ was diffused into the Si(100) substrate with 5 micrometer deep. In order to get a micron size cantilver a conventional procedure including oxidation, patterning and wet KOH etching were imployed. The shape of a tip was fabricated on the front side of the substrate by patterning procedure followed by reactive ion etching(RIE) and a sharpening oxidation followed by oxide strip. We are successfully able to get a tip with radius less than 20 using an silicon-dioxide mask, rather than using a photoresist mask layer.
Controlled infiltration profile of SiC coating layer on graphite by Si vapor deposition reaction
Kuk-Jin Hwang,Si-Young Bae,Kyoung-Ho Kim,Yoon-Cheol Lee,Jung-Tae Hwang,Heesoo Lee,Seong Min Jeong,Myung-Hyun Lee 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.2
SiC-coated graphite was successfully fabricated at different temperatures (1300-1600 oC) through a silicon vapor depositionreaction (Si-VDR) process. Si powder was used for the Si source of the SiC coating layers. When Si powder was evaporatedat high temperature near the melting point of bulk Si, Si gases are moved and changed into Si liquid at the surface of thegraphite. The high-temperature process facilitated the formation of SiC coating layers on the graphite. The microstructural,mechanical, and thermal oxidation properties of the coated graphite were investigated.
Comparative Analysis and Safety Standard Guideline of AC and DC Supplied Home Appliances
Jung-Hoon Ahn,Keun-Wan Koo,Dong-Hee Kim,Byoung-Kuk Lee,Hyun-Cheol Jin 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5
This paper analyzes AC and DC supplied home appliances comparatively for check of existing safety standards as DC power supply system serviced at home. Firstly, DC appliance model that is devised to suit dc distribution system by this paper is compared with AC appliance for analysis of the difference. Secondly, international safety standards of AC appliances are analyzed. In conclusion, for DC safety standards setup, this paper guides intelligence of what kinds of safety standards should be complemented for eliminating risk caused by distribution system change in many standards.
Jung-Hoon Ahn,Dong-Hee Kim,Byoung-Kuk Lee,Hyun-Cheol Jin,Jae-Sun Shim 대한전기학회 2012 Journal of Electrical Engineering & Technology Vol.7 No.1
This paper provides a safety guideline for DC supplied home appliances through the comparative analysis of existing safety guideline for AC supplied home appliances. For this purpose, a predictive DC home appliance model is suggested and in special international safety standards of AC appliances are also analyzed. Moreover, a DC distribution system is built to verify the validity of the proposed safety guideline. The detailed analyzing process is explained with help of informative experimental results.