• Applied Microscopy
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• 제17권1호
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• pp.16-28
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• 1987

Carlaviruses were isolated from naturally infected medicinal plants, and identified by means of test plants and electron microscopy. Mottle symptoms were shown on leaves of Panax ginseng, Aralia cordata, Xanthium strumarium, Taraxacum officinale, Aconitum carmichaeli, and Bupleurum longiradiatum var. breviradiatum. Ring spot on leaves of Abutilon avicennae and ring mosaic or vein clearing on leaves of Sambucus sieboldiana were also shown. These viruses had rather narrow host ranges by mechanical inoculation. The virus particles were scattered or aggregated in cytoplasm of infected host plant leaves. The carlaviruses for which the name panax virus S (PaVS), aralia virus S (ArVS), xanthium mottle virus (XaVS), taraxacum virus S (TaVS), aconite mottle virus (AcMV), bupleurum virus S (BuVS) and abutilon ring spot virus (AbRSV) were proposed, had flexuous particles with width 13 nm and length $620{\sim}720nm$. A reported elder ring mosaic virus was isolated from leaves of Sambucus sieboldiana with ring mosaic or vein-clear symptoms.

• 대한수학회지
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• 제46권5호
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• pp.1027-1040
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• 2009

A ring R is called IFP, due to Bell, if ab = 0 implies aRb = 0 for a, b $\in$ R. Huh et al. showed that the IFP condition is not preserved by polynomial ring extensions. In this note we concentrate on a generalized condition of the IFPness that can be lifted up to polynomial rings, introducing the concept of quasi-IFP rings. The structure of quasi-IFP rings will be studied, characterizing quasi-IFP rings via minimal strongly prime ideals. The connections between quasi-IFP rings and related concepts are also observed in various situations, constructing necessary examples in the process. The structure of minimal noncommutative (quasi-)IFP rings is also observed.

• 대한수학회보
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• 제43권1호
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• pp.1-7
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• 2006

In this paper, we investigate bounded matrices over regular rings. We observe that every bounded matrix over a regular ring can be described by idempotent matrices and invertible matrices. Let A, $B{in}M_n(R)$ be bounded matrices over a regular ring R. We prove that $(AB)^d = U(BA)^dU^{-1}$ for some $U{\in}GL_n(R)$.

• East Asian mathematical journal
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• 제34권3호
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• pp.305-316
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• 2018

Let R be a ring with identity. A right ideal ideal I of a ring R is called ref lexive (resp. completely ref lexive) if $aRb{\subseteq}I$ implies that $bRa{\subseteq}I$ (resp. if $ab{\subseteq}I$ implies that $ba{\subseteq}I$) for any $a,\;b{\in}R$. R is called ref lexive (resp. completely ref lexive) if the zero ideal of R is a reflexive ideal (resp. a completely reflexive ideal). Let K(R) (called the ref lexive radical of R) be the intersection of all reflexive ideals of R. In this paper, the following are investigated: (1) Some equivalent conditions on an reflexive ideal of a ring are obtained; (2) reflexive (resp. completely reflexive) property is Morita invariant; (3) For any ring R, we have $K(M_n(R))=M_n(K(R))$ where $M_n(R)$ is the ring of all n by n matrices over R; (4) For a ring R, we have $K(R)[x]{\subseteq}K(R[x])$; in particular, if R is quasi-Armendaritz, then R is reflexive if and only if R[x] is reflexive.

• 한국환경농학회지
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• 제12권2호
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• pp.144-152
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• 1993

오염된 하천수, 토양 및 폐기물 침출수등의 미생물 분리원으로 부터 합성세제(ABS)를 유일 탄소원으로 이용할 수 있는 미생물들을 분리하여, 이중 합성세제(ABS) 분해능이 가장 우수한 한 종의 균을 분리하여 동정한 결과 P. fluorescens 또는 그 유연균으로 밝혀졌으며, 최적 생장온도는 $30^{\circ}C$였고 최적 생장 pH는 pH 7.0이었다. 분리균주의 탄화수소 자화능 및 중금속에 대한 내성을 조사한 결과 benzene, cyclohexane, xylene 및 catechol은 탄소원으로 이용할 수 있는 반면 phenol, toluene, salicylate, naphthalene은 탄소원으로 이용하지 못하였으며, 중금속중 zinc chloride, lead nitrate, copper sulfate에 대하여는 강한 내성을 나타내었으나 mercury chloride, silver nitrate에 대하여는 내성이 약했다. 분리균의 합성세제(ABS) 분해율을 조사한 결과 ABS 20${\mu}g$/ml의 농도에서 4일후 약 55%, 100${\mu}g$/ml 농도에서는 약 60% 각각 분해되었다. 합성세제 (ABS) 분해에 따른 benzene ring의 분해율을 조사한 결과 시간이 경과 할수록 합성세제(ABS) 분해에 비례하여 benzene ring도 분해되었다. ABS 농도 20${\mu}g$/ml 및 100${\mu}g$/ml에서 benzene ring은 각각 38% 및 45% 분해되었다. COD의 분해와 ABS 분해를 비교검토한 결과 COD는 배양 24시간까지 급격하게 분해 되었으나 그 이후부터 서서히 계속해서 분해되었으며 ABS는 처음부터 서서히 계속적으로 분해되었다. ABS를 첨가하지 않고 배양한 균과 ABS를 1,000${\mu}g$/ml 농도가 되게 첨가하여 배양한 균과의 균체내 아미노산조성을 비교한 결과 아미노산총량은 각각 104.9mg/g 및 115.0mg/g으로서 ABS를 첨가하여 배양한 분리균에서 9.4% 증가 되었으며, 균체내에 Glx(Glu + Gln) 및 proline이 각각 11.1%, 9.2%로 비교적 많이 함유하고 있었고, 특히 cysteine은 ABS를 첨가하지 않고 배양한 분리균에 비해 ABS를 첨가하여 배양한 균에서 약 2.4배 높게 나타났다. ABS를 첨가하지 않고 배양한 분리균은 산성 아미노산인 Asx(Asp + Asn)와 Glx(Glu + Gln)가 비교적 많이 생성된 반면, ABS를 첨가하여 배양한 분리균에서는 염기성 아미노산인 histidine, lysine 및 argnine이 비교적 많이 생성되었다.

• Kyungpook Mathematical Journal
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• 제54권4호
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• pp.587-593
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• 2014

Let D be an integral domain with quotient field K, $\bar{D}$ denote the integral closure of D in K and * be a star-operation on D. In this paper, we study the *-Nagata ring of AP*MDs. More precisely, we show that D is an AP*MD and $D[X]{\subseteq}\bar{D}[X]$ is a root extension if and only if the *-Nagata ring $D[X]_{N_*}$ is an AB-domain, if and only if $D[X]_{N_*}$ is an AP-domain. We also prove that D is a P*MD if and only if D is an integrally closed AP*MD, if and only if D is a root closed AP*MD.

• Bulletin of the Korean Chemical Society
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• 제15권11호
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• pp.996-1000
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• 1994

Ab initio calculations with various basis sets have been carried out to investigate the geometries and ring inversion barrier of $R_2TiC_3H_6\;and\;R_2TiS_3$, R=Cp and Cl. Optimized geometries of $R_2TiC_3H_6$ showed the four membered ring was planar on Cs symmetry. However, $R_2TiS_3$ complexes were optimized to be stable in the puckered form. The smallest Basis III with STO-3G on Cp ligands gave reasonable results for the calculations of metallocene. The energy barrier for the ring inversion of metallacyclosulfanes, $Cp_2TiS_3$ was computed to be 8.72 kcal/mol at MP2 level. For the Cl system, we reproduced the molecular structure and ring inversion energy with Basis V.

• 대한수학회보
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• 제45권2호
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• pp.285-297
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• 2008

For an endomorphism ${\alpha}$ of a ring R, the endomorphism ${\alpha}$ is called semicommutative if ab=0 implies $aR{\alpha}(b)$=0 for a ${\in}$ R. A ring R is called ${\alpha}$-semicommutative if there exists a semicommutative endomorphism ${\alpha}$ of R. In this paper, various results of semicommutative rings are extended to ${\alpha}$-semicommutative rings. In addition, we introduce the notion of an ${\alpha}$-skew power series Armendariz ring which is an extension of Armendariz property in a ring R by considering the polynomials in the skew power series ring $R[[x;\;{\alpha}]]$. We show that a number of interesting properties of a ring R transfer to its the skew power series ring $R[[x;\;{\alpha}]]$ and vice-versa such as the Baer property and the p.p.-property, when R is ${\alpha}$-skew power series Armendariz. Several known results relating to ${\alpha}$-rigid rings can be obtained as corollaries of our results.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4079-4083
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• 2012

The mechanism of the cycloaddition reaction between singlet state dichlorosilylene germylidene ($Cl_2Si=Ge:$) and acetone has been investigated with B3LYP/6-$31G^*$ and B3LYP/6-$31G^{**}$ method, from the potential energy profile, we predict that the reaction has one dominant reaction pathway. The presented rule of the reaction is that the two reactants firstly form a Si-heterocyclic four-membered ring germylene through the [2+2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge atom in the Si-heterocyclic four-membered ring germylene and the ${\pi}$ orbital of acetone forming a ${\pi}{\rightarrow}p$ donor-acceptor bond, the Si-heterocyclic four-membered ring germylene further combines with acetone to form an intermediate. Because the Ge atom in the intermediate hybridizes to an $sp^3$ hybrid orbital after the transition state, then, the intermediate isomerizes to spiro-heterocyclic ring compound involving Si and Ge (P4) via a transition state.

• 대한화학회지
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• 제42권4호
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• pp.391-397
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• 1998

퓨란 고리를 포함하는 bis-furan lexitropsin에서, DNA minor groove의 염기쌍과 결합하는 중요 부분인 퓨란의 기하학적 구조를 반경험적 방법(MNDO)과 ab initio(Hartree-Fock) 방법으로 최적화 시켰다. 최적화된 구조에 대해 6-31G와 $6-31G^{\ast}$ basis set을 사용하여 전자적 구조와 양성자 친화도를 구하였다. 아울러 퓨란의 양성자 친화도에 미치는 치환기 효과를 알아보기 위해 전자를 주는 기와 전자를 끄는 기를 갖는 여러 치환 퓨란에 대해 양성자 친화도를 조사하였다. 그 결과 전자를 주는 기는 퓨란의 양성자 친화도를 증가시키는 반면 전자를 끄는 기는 양성자 친화도를 감소시켰으며, 이 결과 치환 퓨란의 산소 원자의 atomic charge와 전자밀도로 설명할 수 있었다