Abstract: Compositions and methods for depositing gold alloys are disclosed. The compositions include certain dithiocarboxylic acids, salts and esters thereof and mercapto group containing compounds which provide bright gold alloy deposits with uniform color.

Abstract: Compositions and methods for depositing gold alloys are disclosed. The compositions include certain dithiocarboxylic acids, salts and esters thereof and mercapto group containing compounds which provide bright gold alloy deposits with uniform color.

Abstract: The present invention discloses an interactive digital learning system and method using multiple representations to assist in geometry proofs. The system of the present invention links to a computer and comprises a database, a problem representation unit, a proof representation unit and a visual representation unit. The database respectively links to the computer, problem representation unit, proof representation unit and visual representation unit and has a geometry proof problem containing a given condition, a prove statement, a static geometric figure and a solution. The problem representation unit displays the geometry proof problem. The solution is presented in a formal proof unit and a proof tree unit in form of short-answer questions, multi-choice questions and logic arrangement tests to train students. The visual representation unit presents the static geometric figure and a dynamic geometric figure to deepen the students' comprehension on geometry proof problem.

Abstract: Compositions and methods for depositing gold alloys are disclosed. The compositions include certain dithiocarboxylic acids, salts and esters thereof and mercapto group containing compounds which provide bright gold alloy deposits with uniform color.

Abstract: Compositions and methods for depositing gold alloys are disclosed. The compositions include certain dithiocarboxylic acids, salts and esters thereof and mercapto group containing compounds which provide bright gold alloy deposits with uniform color.