This work reports a newly developed two-step hydrothermal method for the synthesis of monodispersed colloidal carbon spheres (CCS) under mild conditions. Using this approach, monodispersed CCS with diameters ranging from 160 to 400 nm were synthesized with a standard deviation around 8%. The monomer concentration ranging from 0.1 to 0.4 M is in favor of generation of narrower size distribution ...

Hollow carbon spheres (HCS) with a nanoporous shell are promising for the use in lithium-sulfur batteries because of the large internal void offering space for sulfur and polysulfide storage and confinement. However, there is an ongoing discussion whether the cavity is accessible for sulfur. Yet no valid proof of cavity filling has been presented, mostly due to application of unsuitable high-va...

Fixing the value of Avogadro’s constant, the number of atoms in 12 grams of carbon-12, at exactly 84446886 would imply that one gram is the mass of exactly 18×14074481 carbon-12 atoms. This new definition of the gram, and thereby also the kilogram, is precise, elegant and unchanging in time, unlike the current 118-year-old artifact kilogram in Paris and the proposed experimental definitions of ...

The chemical-vapor-deposition (CVD) process is sufficiently well developed to allow the large-scale production of carbon nanotubes (CNTs). Metal nanoparticles (Fe, Co, Ni, etc.) are usually immobilized on a solid support and then decompose the gaseous hydrocarbon feedstocks into fragmented carbon units at elevated temperatures of 700-1100°C. Metal carbides are formed and then these dominate the...

Let P be a set of n points in R, and k ≤ n an integer. A sphere σ is k-rich with respect to P if |σ ∩ P | ≥ k, and is η-nondegenerate, for a fixed fraction 0 < η < 1, if no circle γ ⊂ σ contains more than η|σ ∩ P | points of P . We improve the previous bound given in [1] on the number of k-rich η-nondegenerate spheres in 3space with respect to any set of n points inR, from O(n/k+n/k), which hol...

Titania coated silica spheres (SiO2@TiO2) prepared by heterocoagulation of silica and titania nano-particles were investigated as catalyst in he photodegradation of rhodamine B (RB) in aqueous solution. The silica spheres were prepared by the well-known Stöber method and titania ol by a hydrolysis–condensation reaction in acidic media. The uncoated and coated particles were characterized by zet...

In this paper we prove that for every bumpy Finsler metric F on every rationally homological n-dimensional sphere Sn with n ≥ 2, there exist always at least two distinct prime closed geodesics.