89 research outputs found
Multiple-spin coherence transfer in linear Ising spin chains and beyond: numerically-optimized pulses and experiments
We study multiple-spin coherence transfers in linear Ising spin chains with
nearest neighbor couplings. These constitute a model for efficient information
transfers in future quantum computing devices and for many multi-dimensional
experiments for the assignment of complex spectra in nuclear magnetic resonance
spectroscopy. We complement prior analytic techniques for multiple-spin
coherence transfers with a systematic numerical study where we obtain strong
evidence that a certain analytically-motivated family of restricted controls is
sufficient for time-optimality. In the case of a linear three-spin system,
additional evidence suggests that prior analytic pulse sequences using this
family of restricted controls are time-optimal even for arbitrary local
controls. In addition, we compare the pulse sequences for linear Ising spin
chains to pulse sequences for more realistic spin systems with additional
long-range couplings between non-adjacent spins. We experimentally implement
the derived pulse sequences in three and four spin systems and demonstrate that
they are applicable in realistic settings under relaxation and experimental
imperfections-in particular-by deriving broadband pulse sequences which are
robust with respect to frequency offsets.Comment: 11 page
Facile and efficient one-pot multicomponent synthesis of a new class of substituted pyrimidine containing imidazoles catalyzed by ceric ammonium nitrate: Screening in vitro microbiological evaluation with various microorganisms
An effective and simple method for the one-pot synthesis of 4,6-diaryl-2-(2-aryl-4,5-diphenyl-1H-imidazol-1-yl)pyrimidines 13-24 from substituted 2-amino pyrimidine 1-12, benzil, substituted aromatic aldehyde and ammonium acetate in methanol by using ceric ammonium nitrate (CAN) as catalyst has been described. This CAN catalyzed reactions are carried out at a temperature of 70-75°C and give very high yields in a lesser reaction time. All the synthesized compounds have been characterized by elemental analysis, FT-IR, 1H NMR 13C NMR and MS spectral data. All the newly synthesized compounds are tested for their in vitro antimicrobial activity against selected clinically isolated bacterial and fungal strains by disc diffusion and minimum inhibitory concentration method
Discovery of the peculiar supernova 1998bw in the error box of GRB980425
The discovery of X-ray, optical and radio afterglows of gamma-ray bursts
(GRBs) and the measurements of the distances to some of them have established
that these events come from Gpc distances and are the most powerful photon
emitters known in the Universe, with peak luminosities up to 10^52 erg/s. We
here report the discovery of an optical transient, in the BeppoSAX Wide Field
Camera error box of GRB980425, which occurred within about a day of the
gamma-ray burst. Its optical light curve, spectrum and location in a spiral arm
of the galaxy ESO 184-G82, at a redshift z = 0.0085, show that the transient is
a very luminous type Ic supernova, SN1998bw. The peculiar nature of SN1998bw is
emphasized by its extraordinary radio properties which require that the radio
emitter expand at relativistical speed. Since SN1998bw is very different from
all previously observed afterglows of GRBs, our discovery raises the
possibility that very different mechanisms may give rise to GRBs, which differ
little in their gamma-ray properties.Comment: Under press embargo at Nature (submitted June 10, 1998
Anomalous Viscosity Reduction and Hydrodynamic Interactions of Polymeric Nanocolloids in Polymers
Nanoscale depth-resolved polymer dynamics probed by the implantation of low energy muons
Between text and stage: the theatrical adaptations of J.M. Coetzee’s Foe
Several of J.M. Coetzee’s novels have been adapted successfully for the stage, both as theatrical and operatic versions, but these adaptations have not received much critical attention. This article examines the ways in which Peter Glazer and Mark Wheatley have adapted Coetzee’s novel Foe (1986), resulting in two different and distinct stage productions, performed in the US and the UK respectively. In order to explore the complex relationship between the published text and the play versions, the article will ground itself in theories of adaptation, drawing extensively on work by Linda Hutcheon and Robert Stam and Alessandra Raengo. One of the key ideas in adaptation theory is that adaptive fidelity to the source text is neither possible nor desirable, but that adaptation is a more complex, multi-layered intertextual and intermedial interplay of fictional material. The article discusses the two play scripts and analyses the adaptive choices which underpin them and how these structure their meaning-making. Finally, the article also suggests that these scripts can be used to throw more light on Coetzee’s enigmatic novel.DHE
Software for the frontiers of quantum chemistry:An overview of developments in the Q-Chem 5 package
This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange–correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear–electronic orbital method, and several different energy decomposition analysis techniques. High-performance capabilities including multithreaded parallelism and support for calculations on graphics processing units are described. Q-Chem boasts a community of well over 100 active academic developers, and the continuing evolution of the software is supported by an “open teamware” model and an increasingly modular design
A Study on Cheminformatics and its Applications on Modern Drug Discovery
AbstractDiscovering drugs to a disease is still a challenging task for medical researchers due to the complex structures of biomolecules which are responsible for disease such as AIDS, Cancer, Autism, Alzimear etc. Design and development of new efficient anti-drugs for the disease without any side effects are becoming mandatory in the recent history of human life cycle due to changes in various factors which includes food habit, environmental and migration in human life style. Cheminformaticds deals with discovering drugs based in modern drug discovery techniques which in turn rectifies complex issues in traditional drug discovery system. Cheminformatics tools, helps medical chemist for better understanding of complex structures of chemical compounds. Cheminformatics is a new emerging interdisciplinary field which primarily aims to discover Novel Chemical Entities [NCE] which ultimately results in design of new molecule [chemical data]. It also plays an important role for collecting, storing and analysing the chemical data. This paper focuses on cheminformatics and its applications on drug discovery and modern drug discovery techniques which helps chemist and medical researchers for finding solution to the complex disease
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