Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v...Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v) =2. The L(d, 1)-labeling number of G, lambda_d(G) is theminimum range span of labels over all such labelings, which is motivated by the channel assignmentproblem. We consider the question of finding the minimum edge span beta_d( G) of this labeling.Several classes of graphs such as cycles, trees, complete k-partite graphs, chordal graphs includingtriangular lattice and square lattice which are important to a telecommunication problem arestudied, and exact values are given.展开更多
Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki r...Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki reaction.The structures of the new compounds synthesized were confirmed by elemental analysis,IR,1H NMR and MS.This new method makes a feature of low cost and readily available starting material,fewer steps,mild condition,easiness to operate and higher yield.展开更多
以D-氨基葡萄糖盐酸盐、间硝基苯甲酸和对甲基苯甲酸为原料,先将氨基葡萄糖的羟基加以保护,然后以N,N-二环已基碳二亚胺(DCC)为脱水剂,合成N-硝基苯甲酰基-1,3,4,6-四-O-乙酰基-2-脱氧-β-D-氨基葡萄糖.产品结构经傅里叶变换红外光谱(FT...以D-氨基葡萄糖盐酸盐、间硝基苯甲酸和对甲基苯甲酸为原料,先将氨基葡萄糖的羟基加以保护,然后以N,N-二环已基碳二亚胺(DCC)为脱水剂,合成N-硝基苯甲酰基-1,3,4,6-四-O-乙酰基-2-脱氧-β-D-氨基葡萄糖.产品结构经傅里叶变换红外光谱(FT-IR)及核磁共振氢谱(1 H NMR)表征确认.研究表明:1,3,4,6-四-O-乙酰基-2-脱氧-β-D-氨基葡萄糖、DCC和间硝基苯甲酸/对甲基苯甲酸的摩尔比为1∶1.5∶1.5,反应温度为40℃,反应时间为4h为最佳反应条件.展开更多
文摘Given a graph G and a positive integer d, an L( d, 1) -labeling of G is afunction / that assigns to each vertex of G a non-negative integer such that |f(u)-f (v) | >=d ifd_c(u, v) =1;|f(u)-f(v) | >=1 if d_c(u, v) =2. The L(d, 1)-labeling number of G, lambda_d(G) is theminimum range span of labels over all such labelings, which is motivated by the channel assignmentproblem. We consider the question of finding the minimum edge span beta_d( G) of this labeling.Several classes of graphs such as cycles, trees, complete k-partite graphs, chordal graphs includingtriangular lattice and square lattice which are important to a telecommunication problem arestudied, and exact values are given.
文摘Six N-alkyl-4＇-methyl-1,1＇-biphenyl-2-sulfonamides were synthesized facilely and efficiently from low cost and readily available benzenesulfonyl chloride and C1-C4 fatty amines via linking DoM reaction with Suzuki reaction.The structures of the new compounds synthesized were confirmed by elemental analysis,IR,1H NMR and MS.This new method makes a feature of low cost and readily available starting material,fewer steps,mild condition,easiness to operate and higher yield.
文摘以D-氨基葡萄糖盐酸盐、间硝基苯甲酸和对甲基苯甲酸为原料,先将氨基葡萄糖的羟基加以保护,然后以N,N-二环已基碳二亚胺(DCC)为脱水剂,合成N-硝基苯甲酰基-1,3,4,6-四-O-乙酰基-2-脱氧-β-D-氨基葡萄糖.产品结构经傅里叶变换红外光谱(FT-IR)及核磁共振氢谱(1 H NMR)表征确认.研究表明:1,3,4,6-四-O-乙酰基-2-脱氧-β-D-氨基葡萄糖、DCC和间硝基苯甲酸/对甲基苯甲酸的摩尔比为1∶1.5∶1.5,反应温度为40℃,反应时间为4h为最佳反应条件.
