• 제목/요약/키워드: p-atom

검색결과 337건 처리시간 0.024초

WAVELET CHARACTERIZATIONS OF VARIABLE HARDY-LORENTZ SPACES

  • Yao He
    • 대한수학회보
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    • 제61권2호
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    • pp.489-509
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    • 2024
  • In this paper, let q ∈ (0, 1]. We establish the boundedness of intrinsic g-functions from the Hardy-Lorentz spaces with variable exponent Hp(·),q(ℝn) into Lorentz spaces with variable exponent Lp(·),q(ℝn). Then, for any q ∈ (0, 1], via some estimates on a discrete Littlewood-Paley g-function and a Peetre-type maximal function, we obtain several equivalent characterizations of Hp(·),q(ℝn) in terms of wavelets.

HQSAR Study on Substituted 1H-Pyrazolo[3,4-b]pyridines Derivatives as FGFR Kinase Antagonists

  • Bhujbal, Swapnil P.;Balasubramanian, Pavithra K.;Keretsu, Seketoulie;Cho, Seung Joo
    • 통합자연과학논문집
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    • 제10권2호
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    • pp.85-94
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    • 2017
  • Fibroblast growth factor receptor (FGFR) belongs to the family of receptor tyrosine kinase. They play important roles in cell proliferation, differentiation, development, migration, survival, wound healing, haematopoiesis and tumorigenesis. FGFRs are reported to cause several types of cancers in humans which make it an important drug target. In the current study, HQSAR analysis was performed on a series of recently reported 1H-Pyrazolo [3,4-b]pyridine derivatives as FGFR antagonists. The model was developed with Atom (A) and bond (B) connection (C), chirality (Ch), hydrogen (H) and donor/acceptor (DA) parameters and with different set of atom counts to improve the model. A reasonable HQSAR model ($q^2=0.701$, SDEP=0.654, NOC=5, $r^2=0.926$, SEE=0.325, BHL=71) was generated which showed good predictive ability. The contribution map depicted the atom contribution in inhibitory effect. A contribution map for the most active compound (compound 24) indicated that hydrogen and nitrogen atoms in the side chains of ring B as well as hydrogen atoms in the side chain of ring C and the nitrogen atom in the ring D contributed positively to the activity in inhibitory effect whereas, the lowest active compound (compound 04) showed negative contribution to inhibitory effect. Thus results of our study can provide insights in the designing potent and selective FGFR kinase inhibitors.

Peroxo Vanadium(Ⅴ)화합물들에 의한 산소 원자 전이 반응에 관한 연구 (Studies on the oxygen-Atom-Transfer Reactions of Peroxo Vanadium(Ⅴ) Complexes)

  • 원태진
    • 대한화학회지
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    • 제45권3호
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    • pp.213-218
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    • 2001
  • Peroxo-vanadium(V) 화합물인 $VO(O_2)_2(pic)^{2-}$$VO(O_2)(nta)^{2-}$ 그리고 $VO(O_2)(dipic)^-$는 pH4.0의 수용액 안에서 thiolato-cobalt(III)화합물인 $(en)_2$Co$($SCH_2CH_2NH_2$)^{2+}$와 산소 원자 전이 반응을 일으킨다. 이들의 산소 원자 전이 반응에서 각각(35$\pm$1)와 $(4.8{\pm}0.4){\times}10^{-2}$ 그리고 $(8.6{\pm}0.5){\times}10^{-4}$의 속도상수($M^{-1}$$S^{-1}$)을 얻었다. $VO(O_2)_2(pic)^{2-}$에 배위되어 있는 peroxide는 산소 원자 전이 반응에서 활성화되어지나 $VO(O_2)(nta)^{2-}$$VO(O_2)(dipic)^-$에 배위되어 있는 peroxide는 불활성화된다. 우리는 이 논문에서 peroxo vanadium(V) 화합물의 산소 원자 전이의 반응 경로는 친전자성의 peroxide 리간드가 친핵성의 substrate와 직접적인 반응에 의하여 이루어진다고 제안하였다.

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3D-QSARs of Herbicidal 2-N-Phenylisoindolin-1-one Analogues as a New Class of Potent Inhibitors of Protox

  • Soung, Min-Gyu;Lee, Yoon-Jung;Sung, Nack-Do
    • Bulletin of the Korean Chemical Society
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    • 제30권3호
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    • pp.613-617
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    • 2009
  • 3D-QSARs for the inhibition activities against protox by herbicidal 2-N-phenylisoindolin-1-one derivatives were studied quantitatively using CoMFA and CoMSIA methods. The result of the statistical quality of optimized CoMSIA model 2 ($FF:\;{r^2}_{cv.};\;0.973\;&\;{r^2}_{ncv.};\;0.612$) was higher than that of CoMFA model 1 ($AF:\;{r^2}_{cv.};\;0.414\;&\;{r^2}_{ncv.};\;0.909$). Also, the relative contribution of the optimized CoMSIA model 2 showed the steric (24.6%), electrostatic (31.0%), hydrophobic (ClogP, 23.4%) and H-bond acceptor field (21.0%), respectively. From the results of the contour maps, the protox inhibition activities are expected to increase when steric favor and H-bond acceptor favor groups are substituted on $R_2$ position and positive favor group are substituted on $C_2,\;C_3,\;and\;C_5$ atom in phenyl ring of $R_2$ position. And the inhibition activities are expected to increase when hydrophobic favor group is substituted on $C_1,\;C_3$ atom in phenyl ring of $R_2$ position and $C_1$ atom of $R_2$ position and hydrophilic favor groups are substituted on $C_4$ atom in phenyl ring of $R_1$ position and the terminal group of $R_1$ position.

X-ray crystal structure of two-dimensional bimetallic host clathrate with 2-aminoethanol, [Cd{NH2CH2CH2OH}2Ni(CN)4]·3C6H5NH2·H2O

  • Kim, Chong-Hyeak;Moon, Hyoung-Sil;Lee, Sueg-Geun
    • 분석과학
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    • 제21권6호
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    • pp.562-568
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    • 2008
  • A novel two-dimensional cadmium(II)-nickel(II) bimetallic host clathrate, $[Cd{NH_2CH_2CH_2OH}_2Ni(CN)_4]{\cdot}3C_6H_5NH_2{\cdot}H_2O$, 1, has been synthesized and structurally characterized by X-ray single crystallographic method. The clathrate 1 crystallizes in the monoclinic system, space group $P2_1/c$ with a = 14.370(3), b = 7.728(1), c = 28.172(4) ${\AA}$, ${\beta}=97.58(1)^{\circ}$, V = 3101.1(9) ${\AA}^3$, Z = 4. The host framework of the clathrate 1 is built of the cyanide bridges between octahedral Cd(II) atom and square planar Ni(II) atom. The octahedral Cd atoms ligated by two 2-aminoethanol molecules and four cyanide ligands bridged with square planar Ni atoms. The Ni atoms bridges to four Cd atoms via cyanides is made up of puckered quadrangles of composition $\{CdNi(CN)_2\}_2$, all edges are shared. This cyanide bridges form an infinite two-dimensional host networks stacking along b axis. 2-Aminoethanol ligands bond to Cd atom through N atom as a monodentate ligand in the axial position and four cyanides take an equatorial plane with all in trans-configurations. The aniline guest molecules and water molecules are located in between the host layer sheets, respectively.

고분자 첨가제인 난연제로서의 수산화마그네슘계 물질의 합성과 특성 (Synthesis and Characteristics of Magnesium Hydroxide Group Flame Retardant for Polymer Addtives)

  • 이동규;강국현;이진화
    • 한국응용과학기술학회지
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    • 제26권4호
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    • pp.385-393
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    • 2009
  • Different types magnesium hydroxide groups have been obtained using the hydrothermal precipitation technique from magnesium sulfate and calcium carbonate solution. The Mg atom coordinated around O atom of ${SO_4}^{2-}$ in another layer to form a multi-layer structure crystal. The influence of synthesis parameters on the morphological characteristics and size of magnesium hydroxide groups precipitated in aqueous were investigated such as different of additive and pH. Magnesium hydroxide groups were decomposed gradually and converted finally to MgO particles after heated in air temperature up to $1050^{\circ}C$. The particle size and it's distribution morphology, crystal phase and thermal behavior of the samples were characterized through XRD, SEM, EDS, and TG/DTA.

Effects of Nitrogen Defect on Magnetism of Cu-doped InN: First-principles Calculations

  • Kang, Byung-Sub;Chae, Kwang-Pyo;Lee, Haeng-Ki
    • Journal of Magnetics
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    • 제18권2호
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    • pp.81-85
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    • 2013
  • We investigate the electronic and magnetic properties in Cu-doped InN with the N vacancy ($V_N$) from first principles calculations. There is the long-range ferromagnetic order between two Cu atoms, attributed to the hole-mediated double exchange through the strong p-d interaction between the Cu atom and neighboring N atom. The system of $V_N$ defect in Cu-doped InN has the lowest formation energy. Due to the hybridization between the Cu-3d and $V_N$ states, the spin-polarization on the Cu atoms in the InN lattice is reduced by $V_N$ defect. So, it shows a weak ferromagnetic behavior.

거대고리 Chlorotetraamine Cadmium(II) 착물의 합성과 분자 구조 (Synthesis and Molecular Structure of Macrocyclic Chlorotetraamine Cadmium(II) Complex)

  • 최기영;서일환;추금홍
    • 한국결정학회지
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    • 제11권3호
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    • pp.133-136
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    • 2000
  • The molecular structure of [Cd(L)Cl]Cl·2H₂O(1)(L=3,14-dimethyl-2,6,13,17-tetraazatricyclo[14,4,0/sup 1.18/,0/sup 7.12/]docosane) has been determined by X-ray diffraction. Crystallographic dta for 1: triclinic space group P1, a=9.671(1), b=10.784(1), c=12.679(2)Å, α=112.31(1), β=99.49(1), γ=93.95(1)°, V=1230.6(3)ų, Z=2, R=0.0779. The coordination of the cadmium atom is a distorted square-pyramid with four secondary amines of the macrocycle occupying the basal sites (Cd-N/sub av/=2.300(3)Å) and a terminal chlorine atom at the axial position with a Cd-Cl(1) distance of 2.463(2)Å.

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Ab Initio Study of Mechanism of Forming Germanic Bis-Heterocyclic Compound between Dimethyl-Germylene Carbene (Me2Ge=C:) and Acetone

  • Lu, Xiuhui;Che, Xin;Lian, Zhenxia;Li, Yongqing
    • Bulletin of the Korean Chemical Society
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    • 제32권1호
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    • pp.89-94
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    • 2011
  • The mechanism of the cycloaddition reaction of forming germanic bis-heterocyclic compound between singlet dimethylgermylene carbene and acetone has been investigated with CCSD(T)//B3LYP/6-$31G^*$ method. From the potential energy profile, it can be predicted that, this reaction has one dominant channel. The presented rule of this dominant channel is that the two reactants firstly form a four-membered ring carbene (RC4) through the [2+2] cycloaddition reaction. Due to $sp^2$ hybridization of carbene C atom in RC4, RC4 further combines with acetone to form a reactant complexe (RC5). Due to the further $sp^3$ hybridization of carbene C atom in RC4, RC5 isomerizes to a germanic bisheterocyclic compound (P6) via the transition state (TS5).

HYDROGEN EMISSION SPECTRA OF QUIESCENT PROMINENCES

  • Kim, Kap-Sung
    • 천문학회지
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    • 제23권1호
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    • pp.71-82
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    • 1990
  • Theoretical calculations of the combined radiative transfer and statistical equilibrium equation including the charge-particle conservations have been earned out for a multilevel hydrogen atom in quiescent prominences. Cool and dense models show the steep changes of population and radiation field in the vicinity of the surface, while these physical quantities remain unchanged for models with temperature of 7,300K, regardless of total densities. Ionization rate of hydrogen atom related with metallic line formation varies in considerable amounts from the surface to the center of model prominences cooler than 6,300K. However, such cool models cannot release enough hydrogen line emissions to explain observed intensities. Prominence models with a temperature higher than 8,000K can yield the centrally reversed Lyman line profiles confirmed by satellite EUV observations. We find that queiscent prominence with a density between $2{\times}10^{11}$ and $10^{12}cm^{-3}$ should be in temperature range between 6,300K and 8,300K, in order to explain consistently observed H alpha, beta line emissions and $n_p/n_l$ ratio.

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