芳族自由基阴离子裂解反应的半径典轨迹法研究

研究了芳族自由基负离子裂解反应中沿着反应坐标两个势能超曲面可能存在交叉点的问题.结果表明,沿着该反应坐标可能发生内转换.利用Landau-Zerner模型,研究了通过非绝热带的跃迁几率,并定性地将之与分解速率常数作了比较.     

A SIMPLE LINEARIZATION PROCEDURE FOR OBTAINING R0 FROM INVASIVE EPIDEMIC MODELS

Plant diseases often cause yield losses in agriculture worldwide. In mathematical ecology, the concept of the basic (or basal) reproduction number, R₀, has received little attention in the scientific literature related to phytopathogen transmission in plants. The spread and magnitude of outbreaks, the rate of invasion and infectivity of the etiologic agent, the contact complexities occurring among parasite and host, and its susceptibility and period of infectiousness are very important factors for epidemiological models. These mathematical models, when applied in ecology, can help to understand the spread of infections from phytopathogens (or pests) to plant hosts as well as detect potential risks of contamination or outbreaks by using the basic reproduction number in effective control strategies. In this study, the Maclaurin series concepts on the Force of Infection were applied to derive R₀ expressions from generic epidemiological SIR (Susceptible‐Infected‐Removed) models. Consequently, we were able to obtain these relations from three transmission‐infection model examples. Then, once the expression of Force of Infection is known from the “infectious” problem studied, it is possible to apply this technique to formulate the R₀ relation and guide practicable strategies for dispersing invasive phytopathogen controls.     

A reverse Denjoy theorem Ⅲ

Suppose that C 1 and C 2 are two simple curves joining 0 to ∞, non-intersecting in the finite plane except at 0 and enclosing a domain D which is such that, for all large r, the set {θ : re iθ∈ D} has measure at most 2α, where 0 α π. Suppose also that u is a non-constant subharmonic function in the plane such that u(z) = Φ(|z|) for all large z ∈ C 1 ∪ C 2 ∪～D, where Φ(|z|) is a convex, non-decreasing function of |z| and ～D is the complement of D. Let A D (r, u) = inf{u(z) : z ∈ D and |z| = r}. It is shown that if A D (r, u) = O(1) then lim inf r→∞ B(r, u)/r π/(2α) 0.     

ChemInform Abstract: XeNO3+: A Gaseous Cation Characterized by a Remarkably Strong Xe—O Bond.

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