In the paper, air cavity created by vertical water entry of cylinders with different slenderness ratio (defined as “s=L/D”) is investigated experimentally, theoretically, and computationally. The study focused on range Froude numbers, Fr = V /( gr ) 0.5, (12< Fr< 30). Particular attention given to effect ratios surface seal time, evolution process cavities. To understand physical processe...

We report the first asymmetric, total synthesis of (-)-isosilybin A. A late-stage catalytic biomimetic cyclization of a highly functionalized chalcone is employed to form the characteristic benzopyranone ring. A robust and flexible approach to this chalcone provides an entry to the preparation of the entire isomeric family of silybin natural products.

To examine the relationship between freshwater entry and otolith annular structures, a total of 113 naturally recruited European eels Anguilla anguilla from Lithuania and Latvia that entered fresh water at least once were collected. In some individuals (8.3-11.3%), the first freshwater entry coincided with a dark check that was distinctly different from neighbouring annuli. In most individuals ...

Almost all water that enters the conceptus of the sheep enters via the placenta. The forces that drive water are hydrostatic and osmotic. The placental channels that allow water to cross into the fetus have not been identified by microanatomic means. Although an "equivalent pore" system can account for the diffusional entry of small hydrophilic solutes, it can be calculated that the filtration ...

Ferrocene derived P,S-heterodonor ligands were effectively used in AgOAc catalyzed asymmetric cycloaddition of azomethine ylides. The roles of planar chirality and electronic properties of the phosphorous substituents have been examined, and up to 93% ee was obtained. 2007 Elsevier Ltd. All rights reserved. The 1,3-dipolar cycloaddition reaction has become a powerful synthetic tool, providing a...

Catalytic asymmetric oxidation-chemistry involving heteroatom transfer from a reagent to a substrate is perhaps unparalleled in synthetic utility for the construction of enantioenriched materials.[1] Conversely, there is a significant deficiency of asymmetric two-electron oxidations that do not involve heteroatom transfer. Some potentially valuable reactions of this type include the oxidation o...

We extend the notions of evolutionary stability and neutral stability to asymmetric games played between two populations. Assuming that a single strategy is initially played in each population, we consider the simultaneous entry of small proportions of mutants into both populations. The originally played strategy pair is called neutrally stable if the mutants cannot spread. For bimatrix games, ...