27 research outputs found
Forecasted sales of China sports lottery through 2035.
Forecasted sales of China sports lottery through 2035.</p
Sales of China sports lottery between 2011 and 2022.
The pink line indicates the trend between 2011 and 2019, the red line indicates the trend between 2020 and 2022, and the blue line indicates the overall trend within the data set. The confidence level (shaded region) for the overall data is set at 90%.</p
Fig 2 -
Worm plot of the model residual: (A) stable model; (B) shock model.</p
Sales of China sports lottery modeled with GAMLSS distributions.
Sales of China sports lottery modeled with GAMLSS distributions.</p
On the Nature of Support Effects of Metal Dioxides MO<sub>2</sub> (M = Ti, Zr, Hf, Ce, Th) in Single-Atom Gold Catalysts: Importance of Quantum Primogenic Effect
Fundamental understanding of support
effects and metal–support
interaction is critical in heterogeneous catalysis. In this work,
theoretical investigations are carried out to study the nature of
support effects of different tetravalent-metal dioxides of MO<sub>2</sub> (M = Ti, Zr, Ce, Hf, Th) in single-atom gold catalysts using
density functional theory with on-site Coulomb interactions (DFT+U).
The properties of gold adatom on the stoichiometric (MO<sub>2</sub>) and reduced (MO<sub>2–<i>x</i></sub>) surfaces
as well as CO adsorption on Au<sub>1</sub>/MO<sub>2</sub> and Au<sub>1</sub>/MO<sub>2–<i>x</i></sub> have been investigated
systematically. Our calculations indicate that the fundamental <i>quantum primogenic effect</i> that causes the radial contraction
and low orbital energies of 3d and 4f orbitals in these MO<sub>2</sub> oxides plays a vital role in determining the valence states and
charge distribution of single-atom gold as well as the adsorption
modes of CO on various MO<sub>2</sub> supports. We find that gold
atoms supported on different surfaces exhibit oxidation states from
AuÂ(−I) to Au(0) to AuÂ(I), depending on the nature of the metal
oxide supports. The support-dependent oxidation states and charge
distribution of Au can further influence the adsorption mode of CO.
While CO adsorbs strongly on AuÂ(I) in Au<sub>1</sub>/MO<sub>2</sub> (M = Ti, Ce) via Au–C σ-bonding, weaker adsorption
occurs on Au(0) in Au<sub>1</sub>/MO<sub>2</sub> (M = Zr, Hf, Th)
with charge back-donation to CO 2Ï€* antibonding orbitals. In
contrast, at Au<sub>1</sub>/MO<sub>2–<i>x</i></sub> of reduced support, CO adsorption is stronger for M = Zr, Hf, and
Th than for M = Ce. These results provide essential understanding
on the nature of support effects of metal oxides in heterogeneous
catalysis
Geometries from The influences of ammonia on aerosol formation in the ozonolysis of styrene: roles of Criegee intermediate reactions
Geometries optimized at the B3LYP/6-311G++(2d,2p)
How Much Can Density Functional Approximations (DFA) Fail? The Extreme Case of the FeO<sub>4</sub> Species
A thorough theoretical study of the
relative energies of various
molecular Fe·4O isomers with different oxidation states of both
Fe and O atoms is presented, comparing simple Hartree–Fock
through many Kohn–Sham approximations up to extended coupled
cluster and DMRG multiconfiguration benchmark methods. The ground
state of Fe·4O is a singlet, hexavalent ironÂ(VI) complex <sup>1</sup><i>C</i><sub>2v</sub>-[FeÂ(VI)ÂO<sub>2</sub>]<sup>2+</sup>(O<sub>2</sub>)<sup>2–</sup>, with isomers of oxidation
states FeÂ(II), FeÂ(III), FeÂ(IV), FeÂ(V), and FeÂ(VIII) all lying slightly
higher within the range of 1 eV. The disputed existence of oxidation
state FeÂ(VIII) is discussed for isolated FeO<sub>4</sub> molecules.
Density functional theory (DFT) at various DF approximation (DFA)
levels of local and gradient approaches, Hartree–Fock exchange
and meta hybrids, range dependent, DFT–D and DFT+U models do
not perform better for the relative stabilities of the geometric and
electronic Fe·4O isomers than within 1–5 eV. The Fe·4O
isomeric species are an excellent testing and validation ground for
the development of density functional and wave function methods for
strongly correlated multireference states, which do not seem to always
follow chemical intuition
Rate constants from The influences of ammonia on aerosol formation in the ozonolysis of styrene: roles of Criegee intermediate reactions
The rate constants for bimolecular reactions