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131.
Journal of Nanoparticle Research - Workers are increasingly exposed to nanoparticles, mostly via inhalation. Respiratory protection is recommended as an additional control measure. Particulate...  相似文献   
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This paper deals with the chemotaxis-growth system: ut=Δu???(u?v)+μu(1?u), vt=Δv?v+w, τwt+δw=u in a smooth bounded domain Ω?R3 with zero-flux boundary conditions, where μ, δ, and τ are given positive parameters. It is shown that the solution (u,v,w) exponentially stabilizes to the constant stationary solution (1,1δ,1δ) in the norm of L(Ω) as t provided that μ>0 and any given nonnegative and suitably smooth initial data (u0,v0,w0) fulfills u0?0, which extends the condition μ>18δ2 in [8].  相似文献   
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Medical treatment and vaccination decisions are often sequential and uncertain. Markov decision process is an appropriate means to model and handle such stochastic dynamic decisions. This paper studies the near‐optimality of a stochastic SIRS epidemic model that incorporates vaccination and saturated treatment with regime switching. The stochastic model takes white noises and color noise into account. We first prove some priori estimates of the susceptible, infected, and recovered populations. Moreover, we establish some sufficient and necessary conditions of the near‐optimality by Pontryagin stochastic maximum principle. Our results show that the two kinds of environmental noises have great impacts on the infectious diseases. Finally, we illustrate our conclusions through numerical simulations.  相似文献   
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The synthesis in one‐pot reactions and structural characterization of six new tri‐n‐butyltin(IV) derivatives of Schiff bases are reported. The compounds are derived from a condensation reaction between l ‐alanine, l ‐valine, l ‐isoleucine, l ‐methionine, l ‐phenylalanine or l ‐tryptophan and 3,5‐di‐tert‐butyl‐2‐hydroxybenzaldehyde. Characterization was completed using elemental analysis, infrared spectroscopy, mass spectrometry, one‐ and two‐dimensional solution NMR (1H, 13C and 119Sn) as well as solid‐state 119Sn NMR. In addition, the crystal structures of three of the compounds were confirmed using single‐crystal X‐ray diffraction. Although five‐coordinated and polymeric in the solid state, the tin compounds are four‐coordinated and monomeric in solution. The coordination environment around the triorganotin units comprises three carbon atoms and two oxygen atoms from two ligands in a trigonal bipyramidal geometry. The anti‐proliferative effect of these compounds on the cervical carcinoma cell lines HeLa, CaSki and ViBo was screened in vitro, the compounds showing cytotoxic activity against all three strains and null or low cytotoxic activity (necrotic) as well. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
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We consider Sturm–Liouville eigenvalue problems of second order with arbitary seperated boundary conditions and perform a suitabl discretization of them. The obtained discrete Sturm–Liouville eigenvalue problems are examined and the asymptotic behavior of their eigenvalue as the norm of the partition tends to zero is investigated.  相似文献   
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Ding  Yunqiao  Li  Junying  Wang  Shijie  Junzhang  Mu  Qiuhong  Wang  Jingui 《Structural chemistry》2018,29(5):1499-1510
Structural Chemistry - The reaction mechanisms of several amino acids (Asn, Gln, Arg, His, and Lys) in the collagen with aldehyde were studied using density functional theory method. Based on the...  相似文献   
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