http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Ahmed, Nisar,Suresh, Vangaru,Shirinfar, Bahareh,Geronimo, Inacrist,Bist, Amita,Hwang, In-Chul,Kim, Kwang S. The Royal Society of Chemistry 2012 Organic & biomolecular chemistry Vol.10 No.10
<P><I>Cyclo</I>-bis-(urea-3,6-dichlorocarbazole) (<B>1</B>) forms a 1 : 2 complex with CH<SUB>3</SUB>CO<SUB>2</SUB><SUP>−</SUP> and H<SUB>2</SUB>PO<SUB>4</SUB><SUP>−</SUP> through hydrogen bonding with the two urea moieties, resulting in fluorescence enhancement <I>via</I> a combined photoinduced electron transfer (PET) and energy transfer mechanism. The binding mechanism involves a conformational change of the two urea receptors to a <I>trans</I> orientation after binding of the first anion, which facilitates the second interaction.</P> <P>Graphic Abstract</P><P><I>Cyclo</I>-bis-(urea-3,6-dichlorocarbazole) (<B>1</B>) forms a 1 : 2 complex with CH<SUB>3</SUB>CO<SUB>2</SUB><SUP>−</SUP> and H<SUB>2</SUB>PO<SUB>4</SUB><SUP>−</SUP> through hydrogen bonding with the two urea moieties, resulting in fluorescence enhancement <I>via</I> a combined photoinduced electron transfer (PET) and energy transfer mechanism. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2ob06994f'> </P>
Ahmed, Nisar,Shirinfar, Bahareh,Geronimo, Inacrist,Kim, Kwang S. American Chemical Society 2011 ORGANIC LETTERS Vol.13 No.20
<P>A new water-soluble and fluorescent imidazolium-anthracene cyclophane (<B>1</B>) effectively recognizes the biologically important GTP and I<SUP>–</SUP> over other anions in a 100% aqueous solution of physiological pH 7.4. Fluorescence and <SUP>1</SUP>H NMR spectra and ab initio calculations demonstrate that emission arises from the formation of an excimer state and quenching occurs upon GTP/I<SUP>–</SUP> binding through (C–H)<SUP>+</SUP>···A<SUP>–</SUP> hydrogen bond interactions.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2011/orlef7.2011.13.issue-20/ol202183t/production/images/medium/ol-2011-02183t_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol202183t'>ACS Electronic Supporting Info</A></P>
Naveed Ahmed,Adnan,Umar Khan,Syed Tauseef Mohyud-Din,Ilyas Khan,Kottakkaran Sooppy Nisar 한국자기학회 2020 Journal of Magnetics Vol.25 No.2
The objectives of the research are to explored the heat and mass transport over a paraboloid surface of revolution by taking the effects of Lorentz force, resistive heating and internal heat source. The dimensionless version of the model was attained via similarity transformations. Then, for solution purpose, RK scheme is utilized and performed computations for the flow fields. The influence of different physical quantities on the flow characteristics described comprehensively via graphs. It is examined that the stretching index parameter m opposes the fluid velocity and the temperature enhances for Eckert number. Moreover, significant impacts of the Schmidt number are observed for mass transfer gradient.
Perveiz Khalid,Nisar Ahmed,Khalid Amin Khan,Mustansar Naeem 한국지질과학협의회 2015 Geosciences Journal Vol.19 No.3
The discrimination of hydrocarbon (gas or oil) facies from non-hydrocarbon (wet sands) facies is an important goal in quantitative seismic interpretation and reservoir estimation. The differentiation of hydrocarbon facies from non-hydrocarbon in Mississauga Formation of early Cretaceous in Penobscot area is a difficult task due to smaller net pay thickness and shaly sand intervals. Based on seismic interpretation and wireline logs, five sand plays are identified in the middle of Mississauga Formation. Four sands have hydrocarbons while top of sand 5 represents hydrocarbon water transition zone. Among these four, the pay sand 4 is analyzed for hydrocarbon facies. Wireline logs and seismic data are used to derive various amplitude versus offset (AVO) based attributes such as: acoustic (IP) and shear (IS) impedances, Poisson ratio (σ) etc. Further, the combined attributes e.g., product of Lamé parameters (μ, λ) with density (ρ), their ratio (λ/μ), difference between bulk modulus (K) and shear modulus (μ), Δμρ/μρ, Δ(λ/μ + 2)(λ/μ + 2) and the pore space modulus (ΚP) are also analyzed to find out the best attribute as a hydrocarbon facies discriminator from non-hydrocarbon facies in the shale imbedded pay sand 4 of Mississauga Formation. First, petrophysical parameters such as P and S wave impedances, Lamé’s parameters etc. are extracted from log data. Then, appropriate pairs of seismic attributes are crossplotted so that the hydrocarbon and non-hydrocarbon facies cluster together for quick identification and interpretation. Gamma ray index is crossplotted against spontaneous potential log to mark sand and shale facies. Fluid substitution modeling for various fluid types and saturation is also done which demonstrate that the cross-plots between different rock physics parameters can be used to distinguish between reservoir fluids. Our analysis reveals single P-wave based attributes are not sufficient to discriminate fluids thus the use of multi-attributes such as KP, λρ and Κ-μ is more effective to discriminate the hydrocarbon and non-hydrocarbon facies. The analysis of these cross-plots was done to map the reservoir sands and the hydrocarbon-water contact.
Yousuf, Muhammad,Ahmed, Nisar,Shirinfar, Bahareh,Miriyala, Vijay Madhav,Youn, Il Seung,Kim, Kwang S. American Chemical Society 2014 ORGANIC LETTERS Vol.16 No.8
<P>Cationic cyclophanes with bridging and spacer groups possess well-organized semirigid cavities and are able to encapsulate and stabilize anionic species through diverse molecular interactions. We highlight the precise tuning of functionalized cyclophanes toward selective recognition of AMP, GTP, and pyrophosphate (PPi) using fluorescence, NMR spectroscopy, and density functional theory (DFT).</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2014/orlef7.2014.16.issue-8/ol500613y/production/images/medium/ol-2014-00613y_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol500613y'>ACS Electronic Supporting Info</A></P>
Selective Fluorescent Detection of RNA in Living Cells by Using Imidazolium-Based Cyclophane
Shirinfar, Bahareh,Ahmed, Nisar,Park, Yu Shin,Cho, Gun-Sik,Youn, Il Seung,Han, Jin-Kwan,Nam, Hong Gil,Kim, Kwang S. American Chemical Society 2013 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.135 No.1
<P>A water-soluble imidazolium-based fluorescent chemosensor senses RNA selectively through fluorescence enhancement over other biologically relevant biomolecules in aqueous solution at physiological pH 7.4. Fluorescence image detection of RNA in living cells such as onion cells, HeLa cells, and animal model cells was successfully demonstrated which displays a chelation-enhanced fluorescence effect. These affinities can be attributed to the strong electrostatic (C–H)<SUP>+</SUP>···A<SUP>–</SUP> ionic H-bonding and the aromatic moiety driven π-stacking of imidazolium-based cyclophane with the size-complementary major groove of RNA.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2013/jacsat.2013.135.issue-1/ja3112274/production/images/medium/ja-2012-112274_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja3112274'>ACS Electronic Supporting Info</A></P>
Muhammed Irfan Ehsan,Nisar Ahmed,Perveiz Khalid,Liu Xue Wei,Mustansar Naeem 한국지질과학협의회 2016 Geosciences Journal Vol.20 No.3
Naturally occurring gas hydrates are potential future energy source. A significant amount of gas hydrates is interpreted through seismic reflection data in the form of bottom simulating reflector (BSR) present in the sediments of the convergent continental margin of Pakistan. However, the seismic character of these hydratebearing unconsolidated sediments is not properly investigated. Since no direct measurements are available for quantitative estimation of gas hydrate and free gas in these sediments, therefore detailed knowledge of seismic velocities is essential. Seismic velocities of the gas hydrate-bearing sediments in the study area are estimated by using the effective medium theory and the fluid substitution modeling. The results show that the presence of gas hydrates increases the stiffness of the unconsolidated sediments; whereas the presence of free gas decreases the stiffness of these sediments. It is noted that seismic velocities and density of hydrate-bearing sediments are highly affected by saturation and distribution pattern of gas hydrates. The hydrate-bearing sediments seem to be characterized not only by high P-wave velocity (about 2800 m/s) but also by anomalously low S-wave velocity (about 850 m/s). As pure gas-hydrates have much higher seismic velocities than those of host sediments, presence of gas-hydrate increases the seismic velocities, whereas free-gas below the hydrate-bearing sediments decreases the velocities. Seismic reflection from the BSR exhibits a wide range of amplitude variation with offset characteristics, which depend upon the saturation and distribution of hydrates above and free gas below the BSR. We have also demonstrated that some attributes like acoustic and shear impedances, and AVO can be used as important proxies to detect gas hydrate saturation.
Asghar Ali,Zuhair S. Khan,Mahmood Jamil,Yaqoob Khan,Nisar Ahmad,S. Ahmed 한국물리학회 2018 Current Applied Physics Vol.18 No.5
We developed sulfonated, reduced graphene oxide (S-RGO) through fuming/concentrated sulfuric acid treatment of graphene oxide (GO) in ambient conditions. It was demonstrated that the optical band gap and electrical conductivity of S-RGO are easily tunable, and depend on the level of reduction and sulfonation of GO. Whereas, reduction and sulfonation were found dependent on SO3 content, acid strength, and gas tightness of the reaction mixture. It's actually the water content of oleum that determines the nature of the final product. The easily adjustable band gap and electrical conductivity suggest that S-RGO can be employed as a potential hole extraction layer (HEL) material for several donor-acceptor systems. For P3HT:PC61BM based inverted polymer solar cells, it was observed that the shape of the JeV curve is tailorable with the choice of HEL. Compared to a 2.75% power conversion efficiency (PCE) attained with PEDOT:PSS, a PCE of 2.80% was achieved with tuned S-RGO. Our results imply that an S-RGO of sufficiently high band gap and conductivity can replace some of the state of the art HEL materials for a host of device applications.