) Metalloidal; nonmetallic; -- contracted with positive or basic; as, the nitro group is negative. Negative (n.) A proposition by which something is denied or forbidden; a conception or term formed by prefixing the negative particle to one which is positive; an opposite or contradictory ...
Process for presulphurisation and for control of the activity of a catalyst for hydrocarbon processingProcess for the two-stage treatment of a new or regenerated catalyst containing (a) a support based on at least one oxide of a metal or of a metalloid and (b) at least one active metal,...
Shivashankar K, Hagstrom GR (1991) Molybdenum fertilizer sources and their use in crop production. In: Sichuan C, Portch S (eds) International symposium on the role of sulphur, magnesium, and micronutrients in balanced plant nutrition. Potash and Phosphate Institute, Hong Kong, pp 297–305 Goog...
sulphurising agent so as to incorporate this agent partially or completely in the porosity of the catalyst, the sulphurising agent being an organic polysulphide, the said sulphurising agent being employed in solution in a solvent, in which process, next, in a second stage, the catalyst obtained...
sulphurising agent so as to incorporate this agent partially or completely in the porosity of the catalyst, the sulphurising agent being an organic polysulphide, the said sulphurising agent being employed in solution in a solvent, in which process, next, in a second stage, the catalyst obtained...
A solution or suspension of the condensation product may be used in admixture with a finely divided oxide of a metal or metalloid. In one example a vulcanizate comprises (in parts by weight) natural rubber 38, chalk 35, active gas black 10, soft gas black 15, sulphur 0,5, and a ...
1. A process for the treatment of a fresh or of a regenerated catalyst, comprising a carrier whose main constituent is at least one metal or metalloid oxide and at least one active metal, conducted in the absence of hydrogen and consisting of treating said catalyst with an aqueous solution ...
The invention concerns a method for functionalizing a double bond and, more particularly, a double bond bearing a metalloid atom. Said functionalization is produced by the action of perhalogenated sulphonyl chloride on the carbon bearing sulphur in the presence of a free radical initiator, ...
Specified catalysts are metal and metalloidal halides, their complexes with water and with organic compounds in which the donor atom is oxygen or sulphur, non-oxidizing inorganic anols and their complexes with boron trifluoride, complexes of boton trifluoride with weakly basic nitrogen compounds, ...
As electrophilic catalysts, metal and metalloidal halides, their complexes with compounds in which the donor atom is oxygen or sulphur, non-oxidizing inorganic acids and their complexes with borontrifluoride, complexes of boron trifluoride with very weakly basic nitrogen compounds, halogens and inter...