Based on the double integrator mathematic model, a new kind of potential function is presented in this paper by referring to the concepts of the electric field; then a new formation control method is proposed, in which the potential functions are used between agent-agent and between agent-obstacle, while state feedback control is applied for the agent and its goal. This strategy makes the whole potential field simpler and helps avoid some local minima. The stability of this combination of potential functions and state feedback control is proven. Some simulations are presented to show the rationality of this control method.
The bond length between the C atom in CO2 and O atom in CaO was about 1.39–1.42 Å, and the bond length of C–O in adsorbed CO2 was prolonged to 1.26–1.27 Å, while the O–C–O angle of adsorbed CO2 was about 129°.
Triazolyl phenylalanine and tyrosine-aryl C-glycoside hybrids were readily synthesized via microwave-assisted Cu(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition in high yields. Successive enzymatic assay identified the synthesized glycoconjugates as novel PTP1B inhibitors with low micromole-ranged inhibitory activity and at least several-fold selectivity over other homologous PTPs tested. In addition, the benzyl groups on glucosyl moiety were found crucial toward PTP1B inhibition. Reagents and conditions: (a) TBSCl, pyridine then NaH, BnBr, DMF; (b) AcCl, MeOH then NaH, propargyl bromide, DMF; (c) Na ascorbate, CuSO4•5H2O, CH2Cl2/water, microwave irradiation; (d) LiOH, MeOH/water; (e) PdCl2/C, H2, MeOH Synthesis of Triazole-Linked Amino Acid-Aryl C-Glycoside Hybrids via Click Chemistry Chin.
Both atomic geometry and the influence of surroundings (e.g., exogenously coordinated water) are key issues for determining the chemical environment of oxide surfaces, whereas the latter is usually ignored and should be considered in future studies.
Reactivity of OH and hydride species in oxide-catalyzed
hydrogenation
reactions has attracted great interest. Herein, we report a combined
in situ spectroscopic characterization and density functional theory
(DFT) calculation study of ceria-catalyzed acetylene semihydrogenation
reaction. The ceria surface is fully hydroxylated during the adopted
reaction condition. C2H2 adsorbs molecularly
on the stoichiometric CeO2 surface and hydrogenates with
OH groups selectively to produce C2H4. Semihydrogenation
of C2H2 to C2H4 with either
OH groups or hydride species on ceria surfaces with surface oxygen
vacancies proceeds more facilely than on a stoichiometric CeO2 surface, but C2H4 adsorbs more strongly
and further hydrogenates to C2H6 more facilely;
moreover, dissociative adsorption of C2H2 to
C2H species occurs, which facilely hydrogenates with the
hydride species eventually to form C2H6 and
react with each other to produce oligomers, decreasing the catalytic
selectivity and stability, respectively. These results demonstrate
that the ceria catalyst with a stoichiometric surface is extremely
selective in catalyzing C2H2 semihydrogenation
reaction to C2H4, whereas surface oxygen vacancies
or hydride species on ceria are harmful to the catalytic performance.
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