The effect of rare earths （Sm, Pr, Ce, Nd and La） on the hydrogenation properties ofp-chloronitrobenzene （CNB） over Pt/CNTs catalyst was studied in ethanol at 303 K and normal pressure. The results exhibited that ...The effect of rare earths （Sm, Pr, Ce, Nd and La） on the hydrogenation properties ofp-chloronitrobenzene （CNB） over Pt/CNTs catalyst was studied in ethanol at 303 K and normal pressure. The results exhibited that the hydrogenation of p-CNB could be carried out over PtMOx/CNTs catalysts. Both catalytic activities and yields ofp-chloroaniline （CAN） were all improved. PtCeOx/ CNTs catalyst exhibited the best catalytic activity （TOF was 0.47 s^-1） and the highest yield of p-CAN （97.5 mol%）. PtCeOx/CNTs （1.0 wt%） catalyst exhibited good stability on the hydrogenation of p-CNB.展开更多
Let X＊ be a free monoid over an alphabet X and W be a finite language over X. Let S（W） be the Rees quotient X＊/I（W）, where I（W） is the ideal of X＊ consisting of all elements of X＊ that are not subwords of W....Let X＊ be a free monoid over an alphabet X and W be a finite language over X. Let S（W） be the Rees quotient X＊/I（W）, where I（W） is the ideal of X＊ consisting of all elements of X＊ that are not subwords of W. Then S（W） is a finite monoid with zero and is called the discrete syntactic monoid of W. W is called finitely based if the monoid S（W） is finitely based. In this paper, we give some sufficient conditions for a monoid to be non-finitely based. Using these conditions and other results, we describe all finitely based 2-limited words over a three-element alphabet. Furthermore, an explicit algorithm is given to decide that whether or not a 2-limited word in which there are exactly two non-linear letters is finitely based.展开更多
文摘The effect of rare earths （Sm, Pr, Ce, Nd and La） on the hydrogenation properties ofp-chloronitrobenzene （CNB） over Pt/CNTs catalyst was studied in ethanol at 303 K and normal pressure. The results exhibited that the hydrogenation of p-CNB could be carried out over PtMOx/CNTs catalysts. Both catalytic activities and yields ofp-chloroaniline （CAN） were all improved. PtCeOx/ CNTs catalyst exhibited the best catalytic activity （TOF was 0.47 s^-1） and the highest yield of p-CAN （97.5 mol%）. PtCeOx/CNTs （1.0 wt%） catalyst exhibited good stability on the hydrogenation of p-CNB.
基金Supported by National Natural Science Foundation of China (Grant No. 10971086)Mathematical Tianyuan Foundation of China (Grant No. 11126186)+1 种基金Natural Science Foundation of Gansu Province (Grant No.1107RJZA218)Fundamental Research Funds for Central Universities (Grant No. lzujbky-2012-12)
文摘Let X＊ be a free monoid over an alphabet X and W be a finite language over X. Let S（W） be the Rees quotient X＊/I（W）, where I（W） is the ideal of X＊ consisting of all elements of X＊ that are not subwords of W. Then S（W） is a finite monoid with zero and is called the discrete syntactic monoid of W. W is called finitely based if the monoid S（W） is finitely based. In this paper, we give some sufficient conditions for a monoid to be non-finitely based. Using these conditions and other results, we describe all finitely based 2-limited words over a three-element alphabet. Furthermore, an explicit algorithm is given to decide that whether or not a 2-limited word in which there are exactly two non-linear letters is finitely based.
