Shading Treatment-Induced Changes with Growth and Physiological Characteristics in Delphinium maackianum Regel

조승주,김동학,윤정원,정은주 한국자원식물학회 2025 한국자원식물학회지 Vol.38 No.3

Delphinium maackianum was grown under different shade treatments to examines the impact of different shading levels on the growth, physiological characteristics. The leaf mass per area (LMA) was lowest in the 95% shading treatment, indicating thinner and broader leaves, however significant differences were not observed across shading levels. Chlorophyll content (a, b, and total) increased with higher shading. Fv/Fm and NPQ values showed no significant differences among treatment groups except for the full light treatment, suggesting maintained photosystem II functionality and photoprotective mechanisms. The dark respiration rate (Rd) and light compensation point (LCP) decreased with increased shading, reflecting shade-tolerant plant responses. The 95% shading treatment exhibited the highest photosynthetic rates, light saturation points (LSP), and apparent quantum yields (AQY), indicating enhanced photosynthetic efficiency under low light conditions. Correlation analysis revealed negative relationships between relative light intensity and several physiological traits, including chlorophyll content, LCP, LSP, maximum photosynthetic rate, and AQY. This indicates that D. maackianum optimizes photosynthesis under low light conditions by increasing light absorption and utilization efficiency. The study underscores the species’ ability to adjust its physiological processes and structural characteristics to thrive in varying shading environments, highlighting its adaptive strategies for survival and growth in shaded habitats.

소형 위성 SAR용 Deep Reflector 안테나의 초크 급전기 설계

조승주,임정환,이택경,이재욱 한국전자파학회 2020 한국전자파학회논문지 Vol.31 No.1

본 논문에서는 소형 위성 SAR에 적합한 전개형 반사형 안테나의 급전 안테나로서 초크 안테나를 설계 및 제작하였다. 전개형 안테나의 수납효율에 유리하도록 deep reflector 안테나를 선정하였고, 개구면의 가장자리 테이퍼를 고려하여 급전안테나가 넓은 빔폭을 갖도록 설계하기 위해서 초크 링의 개수와 부착 위치의 최적화를 수행하였다. 설계한 초크 안테나를 반사판 안테나의 급전으로 사용하였을 때의 반사판 안테나 성능을 분석하였으며, 이때의 반사판 안테나 패턴으로부터 SAR 시스템 성능을 분석하여 설계한 초크 안테나가 전개형 안테나의 급전으로써 적합함을 확인하였다.

Theoretical Study of Trioxane Derivatives as Amphi-ionophores: Importance of Charge-Dipolar Moiety Orientation

조승주 대한화학회 2014 Bulletin of the Korean Chemical Society Vol.35 No.9

Recently we have reported a novel class of anion receptors which are based on 2n-crown-n topology. Trioxane derivatives are capable of anion sensing through pure aliphatic C-H hydrogen bonding. In this work, we highlight another interesting property, i.e., they can also recognize cations as normal crown ethers (3n-crownn topology). Since the same functional moiety can recognize anions and cations, these coronands are predicted to be amphi-ionophores. However, we could not detect cations even in the gas phase. Considering trioxane is analogous to [16]starand, this was rather counter-intuitive. The calculation results show that these coronands can detect alkali metals with very low affinity. The low affinity toward cations should be responsible for this failure of experimental detection. With careful theoretical study, we found that this low affinity toward cations could be explained by the unfavorable charge-dipolar moiety orientations as proposed by Cui et al. As in the case of [16]starand, this is an example that underscores the importance of charge-dipolar moiety orientation in supramolecular interactions.

차광처리가 제비붓꽃의 생장 및 생리적 특성에 미치는 영향

조승주,김동학,CHEONG EUN JU,윤정원 한국자원식물학회 2024 한국자원식물학회지 Vol.37 No.2

In this study, we investigated the growth and physiological responses of Iris laevigata Fisch. to shading treatments in order to suggest optimal light conditions for ex-situ conservation of the northern lineage plants. For this purpose, a control plant receiving full sunlight and different shading treatments (50%, 75%, 95%) were installed, and leaf mass per area, chlorophyll content and fluorescence response, and photosynthetic characteristics were investigated. I. laevigata developed leaves with higher photosynthetic efficiency to adapt to lower light intensity as shading levels increased. Chlorophyll content increased with increasing shading levels, and leaf mass per area decreased with increasing leaf area. The chlorophyll fluorescence responses Fv/Fm and NPQ did not change with shading, and the activity of the carbon fixation system did not differ between treatments. I. laevigata exhibited a light-saturation point equivalent to that of sun plants and maintained photosynthetic capacity similar to that of controls up to 75% shading. The apparent quantum yield of I. laevigata decreased significantly at 95% shading, indicating adaptation to lower light conditions. It seems that the photosynthetic capacity of I. laevigata decreases when grown under 95% shading level compared to full sunlight, and it is judged that the longer the light is restricted by continuous shading, the more unfavorable the growth will be.

생물학적 데이터 분석의 총아

조승주,Jo, Seung-Ju 한국과학기술단체총연합회 2004 과학과 기술 Vol.37 No.11

전개형 반사판 안테나의 패널 불완전 전개에 의한 편파특성 영향

조승주,이시아,이택경,이재욱 한국전자파학회 2020 한국전자파학회논문지 Vol.31 No.5

본 논문에서는 전개형 반사판 안테나의 불완전 전개가 안테나의 편파 성능에 미치는 영향에 대해 분석하였다. 포물면의 성질을 이용하는 전개형 반사판 안테나에 불완전 전개가 발생하면 안테나의 형상이 온전한 포물면의 형상을 이루지못하여 안테나의 동일편파 패턴뿐만 아니라, 교차편파 패턴 또한 악화시켰다. 안테나의 불완전 전개가 대칭으로 발생한경우와 비대칭으로 발생한 경우에 대한 안테나 성능 저하의 차이를 조사하였다. 불완전 전개 형상이 대칭인 경우에는교차편파 성능에 미치는 영향이 미약하지만, 비대칭 형상의 경우에는 교차편파가 68 dB 정도 높으며, 교차편파 성능은안테나의 비대칭 형상에 의해 주로 발생하는 것을 확인하였다.

The Importance of Halogen Bonding: A Tutorial

조승주 조선대학교 기초과학연구원 2012 조선자연과학논문집 Vol.5 No.3

Halogen atoms in a molecule are traditionally considered as electron donors, since they have unshared electrons. Normally when they are bonded, there are three lone pair electrons. These lone pairs can function as Lewis bases. However, when they are bound to electron withdrawing groups, they can act as Lewis acids. Since the situation is similar hydrogen bonding (HB), this type of interaction is named as halogen bonding (XB). This mainly comes from the uneven distribution of electron density around the halogen atoms. Since the electron density around halogen atom opposite to σ-bond is depleted, its electropositive region is called σ-hole. This σ-hole can attract halogen bond acceptors, requiring more stringent directionality compared to HB. Since this interaction mainly comes from electrostatic origin, the geometry tends to be linear. Since the XB energy is comparable to corresponding HB. Still in its infancy, XB shows a broad range of applicability, with potentially more useful properties, compared to corresponding HB.

Toward Proper 3D-QSAR Datasets for Parameter Evaluation

조승주 조선대학교 기초과학연구원 2011 조선자연과학논문집 Vol.4 No.3

3D-QSAR techniques including CoMFA have been used a lot for more than two decades now. For now, the perspective of 3D-QSAR has been changed. The realization of gorge activity cliffs and higher chance correlation with many independent variables (IVs) has changed the requirements. Some suggested the benchmarking datasets for 3D-QSAR. However, were they still useful for right reasons? Here, we propose the requirement of any general purpose 3D-QSAR benchmarking datasets for lead optimization, especially for feasibility test of any IVs. Specifically, we summarize the conceptual requirements for an ideal settings for 3D-QSAR especially CoMFA.

부분 전하의 의미와 정의

조승주 조선대학교 기초과학연구원 2010 조선자연과학논문집 Vol.3 No.4

부분 전하의 계산과 응용

조승주 조선대학교 기초과학연구원 2010 조선자연과학논문집 Vol.3 No.4