Wen H.,Central China Normal University |
Zhu C.,Central China Normal University
Advances in Mathematics | Year: 2013
In the paper, we establish a blow-up criterion in terms of the integrability of the density for strong solutions to the Cauchy problem of compressible isentropic Navier-Stokes equations in R3 with vacuum, under the assumptions on the coefficients of viscosity: 29μ3>λ. This extends the corresponding results in Huang et al. (2011), Sun et al. (2011) [20,36] where a blow-up criterion in terms of the upper bound of the density was obtained under the condition 7μ > λ. As a byproduct, the restriction 7μ > λ in Fan et al. (2010), Sun et al. (2011) [12,37] is relaxed to 29μ3>λ for the full compressible Navier-Stokes equations by giving a new proof of Lemma 3.1. Besides, we get a blow-up criterion in terms of the upper bound of the density and the temperature for strong solutions to the Cauchy problem of the full compressible Navier-Stokes equations in R3. The appearance of vacuum could be allowed. This extends the corresponding results in Sun et al. (2011)  where a blow-up criterion in terms of the upper bound of (ρ,1ρ,θ) was obtained without vacuum. The effective viscous flux plays a very important role in the proofs. © 2013 Elsevier Inc.
Luo X.,Central China Normal University
Nuclear Physics A | Year: 2016
Beam energy scan programs in heavy-ion collisions aim to explore the QCD phase structure at high baryon density. Sensitive observables are applied to probe the signatures of the QCD phase transition and critical point in heavy-ion collisions at RHIC and SPS. Intriguing structures, such as dip, peak and oscillation, have been observed in the energy dependence of various observables. In this paper, an overview is given and corresponding physics implications will be discussed for the experimental highlights from the beam energy scan programs at the STAR, PHENIX and NA61/SHINE experiments. Furthermore, the beam energy scan phase II at RHIC (2019–2020) and other future experimental facilities for studying the physics at low energies will be also discussed. © 2016 Elsevier B.V.
Xuan J.,Central China Normal University |
Xiao W.-J.,Central China Normal University
Angewandte Chemie - International Edition | Year: 2012
In the last few years, visible-light initiated organic transformations have attracted increasing attention. The development of visible-light-promoted photocatalytic reactions, which enable rapid and efficient synthesis of fine chemicals, is highly desirable from the viewpoint of cost, safety, availability, and environmental friendliness. In this Minireview, recent advances made in this fast developing area of research are discussed. In the spotlight: The title catalysis is an area of research that is developing quickly and has become a powerful and efficient tool in synthetic organic chemistry (see picture, S=Substrates, P=Products). There is little doubt that continued exploration of visible light photoredox catalysis will uncover a wide range of fascinating and useful chemical reactions. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Luo X.,Central China Normal University
Nuclear Physics A | Year: 2013
We present the measurements of the higher moments of the net-proton multiplicity distributions in Au + Au collisions from the first phase of the beam energy scan program at RHIC. The measurements are carried out at midrapidity (|y| < 0.5) and within the transverse momentum range 0.4 < p T < 0.8 GeV/c by STAR. We report the centrality and energy dependence of the moment products (κσ2 and Sσ), with σ2, S and κ being the variance, skewness and kurtosis, respectively. These moment products are related to the ratios of various order baryon number susceptibilities and sensitive to the correlation length, and hence can be used to search for the QCD critical point. The results are compared to the Poisson expectations, as well as transport model calculations to understand the contributions from effects not related to critical physics. © 2013 Elsevier B.V.
Zhang X.,Ewha Womans University |
Yin J.,Ewha Womans University |
Yin J.,Central China Normal University |
Yoon J.,Ewha Womans University
Chemical Reviews | Year: 2014
The use of fluorescence and colorimetric chemosensors to detect chiral molecules has been a central focus of recent efforts in the field of sensor technologies, owing to the fact that enantiomerically pure compounds and drugs have unparalleled importance in bioscience, clinical medicine, and bionics areas. The most involved chiral recognition mechanism with these sensors is based on hydrogen bond interaction that is employed successfully in organic solvents. This confines these sensors to be used for the water-soluble chiral analyte detections and the chiral recognition applications in physiological environment. The development of the chiral sensors that can be used efficiently in aqueous solutions, such as boronic acid-based sensors or electrostatic sensing systems, should be the focused task in this area. The polymer-based sensors have the capacities to amplify the chiral recognition signal further enhancing the sensitivity and the enantioselectivity. Those macrocyclic scaffolds can utilize their rigid structures to improve the enantioselectivity in the chiral recognition process.
Fu J.,Central China Normal University
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2013
The first four cumulants and ratios of cumulants of net-proton multiplicity distributions are calculated within the hadron resonance gas model. Quantum statistics, resonance decay contributions and the van der Waals excluded volume corrections are taken into account in the model calculations. The corrections due to quantum statistics are small even at the lower RHIC energies. The van der Waals excluded volume procedure leads to a larger suppression of the particle number fluctuations, especially for higher order cumulants. The STAR most central data on the various order cumulants and moment products at the higher RHIC energies are generally below the Poisson expectations and better described by the van der Waals gas with a hadron radius around r=. 0.3. fm. © 2013 Elsevier B.V.
Lu L.-Q.,Central China Normal University |
Chen J.-R.,Central China Normal University |
Xiao W.-J.,Central China Normal University
Accounts of Chemical Research | Year: 2012
Heterocyclic structural architectures occur in many bioactive natural products and synthetic drugs, and these structural units serve as important intermediates in organic synthesis. This Account documents our recent progress in the development of cascade reactions to construct complex carbocycles and heterocycles. We describe the rational design of cascade reactions and in-depth investigations of their mechanism as well as their applications in the synthesis of drugs, natural products, and related molecular analogs.Relying on knowledge about the dipole-type reactivity of sulfur ylides, we have developed three different types of cascade reactions: a [4 + 1] annulation/rearrangement cascade, a [4 + 1]/[3 + 2] cycloaddition cascade, and a Michael addition/N-alkylation cascade. Using these processes, we can generate oxazolidinones, fused heterocycles, and pyrrolines starting with simple and readily available substances such as nitroolefins and unsaturated imines. We have also developed corresponding enantioselective reactions, which are guided by axial chirality and asymmetric H-bonding control. In addition, by relying on the reactivity characteristics of newly designed acrylate-linked nitroolefins, we have disclosed an asymmetric Michael/Michael/retro-Michael addition cascade using the combination of a protected hydroxylamine and a bifunctional organocatalyst. Using this methodology, we prepared chiral chromenes in good yields and with high enantioselectivities. Moreover, a series of double Michael addition cascade reactions with anilines, thiophenols, and benzotriazoles generated highly functionalized chromanes. Via mechanistically distinct cascade processes that start with vinyl-linked indoles, we have synthesized polycyclic indoles. Intermolecular cross-metathesis/intramolecular Friedel-Crafts alkylation cascades, promoted by either a single ruthenium alkylidene catalyst or a sequence involving Grubbs' ruthenium catalyst and MacMillan's imidazolidinone catalyst, converted ω-indolyl alkenes into tetrahydrocarbazoles, tetrahydropyranoindoles, and tetrahydrocarbolines. In addition, we constructed tetrahydrocarbazoles and tetrahydroquinones using organocatalytic Friedel-Crafts alkylation/Michael addition cascades that used 2-vinyl indoles as common starting materials.Most green plants carry out photosynthesis to produce organic substances relying on readily available and renewable solar energy. In a related manner, we have also developed two cascade reactions that merge visible light-induced aerobic oxidation with either [3 + 2] cycloaddition/oxidative aromatization or intramolecular cyclization. These processes lead to the formation of pyrrolo[2,1-a]isoquinolines and enantiopure tetrahydroimidazoles, respectively. © 2012 American Chemical Society.
Central China Normal University and Beijing Yoloo Bio technology Corporation | Date: 2016-08-31
Disclosed are a pyrazole amide compound containing diphenyl ether as represented by formula I and/or formula II, application thereof in the prevention and treatment of rice sheath blight and cucumber powdery mildew, and pesticide composition containing the compound. The pyrazole amide compound of the present invention containing diphenyl ether as represented by formula I and/or formula II, and a bactericide containing the pyrazole amide compound as an active ingredient have good prevention and treatment effects on rice sheath blight and cucumber powdery mildew.
Central China Normal University | Date: 2014-03-11
Disclosed is a derivative of 2-methyl-4-amino-5-(substituted-1H-1,2,3-triazol)methylpyrimidine of general formula I and microbicidal activity thereof. In the formula, R1 represents hydrogen, I; X represents O or NH; Y represents phenyl of substituted phenyl, benzoyl or substituted benzoyl, phenyloxyacetyl or substituted phenyloxyacetyl; the substituents on the phenyl rings which Y involves are: H, halogen, nitro, cyano, CF3, C14 alkyl, methoxyl, C12 carboxyl or carboxylic ester groups; any position of phenyl rings can be mono- or multi-substituted by identical or different substituents. The compound has a significant inhibition effect on cucumber bacterial angular leaf spot, tomato bacterial leaf spot, cucumber brown blot, cucumber downy mildew, rice sheath blight, Gibberella saubinetii, Alternaria solani, Botrytis cinerea, Alternaria alternate and Colletotrichum orbiculare and it can be used as an effective ingredient of microbicides.
Central China Normal University | Date: 2014-02-20
A substituted phenoxyethyl(isopropyl)acyloxyalkyl phosphonate having phosphorusheterocyclic ring and having herbicidal activity, with a general formula of I, wherein R represents 5,5-dimethyl-1,3,2-dioxaphosphorinan-2-one-2-yl, or 1-oxo-1-phospha-2,6,7-trioxabicyclo[2,2,2]octan-4-yl, or 1-sulfo-1-phospha-2,6,7-trioxabicyclo 2,6,7-trioxabicyclo[2,2,2]octan-4-yl; R^(1 )represents H, C1-C4 alkyl, phenyl, furyl, pyridyl, or phenyl substituted with methyl, methoxyl, nitro or chloro; R^(2 )represents H, methyl, and methyl only if R in the general formula I is 1-sulfo-1-phospha-2,6,7-trioxabicyclo[2,2,2]octan-4-yl as phosphorusheterocyclic ring; X and Y represent H, halogen, C1-C4 alkyl or trifluoromethyl, and X and Y are the same or different. The compounds according to the present invention may be used as active component of dicotyledonous broadleaf weed herbicides.