Water/Oil Biphasic Hydroformylation of Higher Olefins over a TPPTS-Rh/SiO2 Catalyst

A novel TPPTS-Rh/SiO2 catalyst, prepared by directly modifying a heterogeneous highsurface-area Rh/SiO2 catalyst with water-soluble TPPTS ligands, could decrease the resistance of mass transfer in water/oil biphasic media for the hydroformylation of higher olefins. The catalytic performance for hydroformylation on this biphasic TPPTS-Rh/SiO2 catalyst system was higher than those of the traditional biphasic HRhCO(TPPTS)3 systems, owing to the chemical bonds between the highly dispersed Rh metal particles and the TPPTS ligands. The catalyst system is applicable for hydroformylation of higher olefins such as 1-dodecene.     

Water／Oil Biphasic Hydroformylation of Higher Olefins over a TPPTS-Rh／SiO2 Catalyst

A novel TPPTS-Rh/SiO2 catalyst, prepared by directly modifying a heterogeneous high-surface-area Rh/SiO2 catalyst with water-soluble TPPTS ligands, could decrease the resistance of masstransfer in water/oil biphasic media for the hydroformylation of higher olefins. The catalytic performancefor hydroformylation on this biphasic TPPTS-Rh/SiO2 catalyst system was higher than those of thetraditional biphasic HRhCO(TPPTS)3 systems, owing to the chemical bonds between the highly dispersedRh metal particles and the TPPTS ligands. The catalyst system is applicable for hydroformylation ofhigher olefins such as 1-dodecene.     

On Existence of the Even Lp Gaussian Minkowski Problem for p > n∗

This paper concerns the even Lp Gaussian Minkowski problem in n-dimensional Euclidean space R n . The existence of the solution to the even Lp Guassian Minkowski problem for p > n is obtained.     

Hydroformylation of methyl-3-pentenoate over a phosphite ligand modified Rh/SiO2 catalyst

A phosphite ligand modified Rh/SiO2 catalyst has been developed for hydroformylation of internal olefins to linear aldehydes, which showed high activity and regioselectivity and could be separated easily by filtration after reaction in an autoclave. Effects of reaction temperature and syngas pressure on the performances of the catalyst in the reaction were also investigated.     

公路边坡岩体分级中坡高修正系数的改进

坡高与边坡稳定性有密切关系。CSMR分级体系在SMR的基础之上针对水电边坡工程引入了坡高修正系数 ,但在公路边坡分级实践中发现 ,该坡高修正系数仍有待于改进。对各类边坡可能失稳形式的力学分析 ,证明坡高修正系数 ξ可近似表示为ξ =a+b/H 的形式。通过对 1 0 0余个边坡样本统计分析 ,得出两种不同岩层、坡面产状组合形式下坡高修正系数的数学表达式。经检验 ,改进后的CSMR体系能够满足公路边坡稳定性初步评价的要求。     

Adaptive stabilization of high order nonholonomic systems with strong nonlinear drifts

This paper investigates the problem of adaptive stabilization control design for a class of high order nonholonomic systems in power chained form with strong nonlinear drifts, including unmodeled dynamics, and dynamics modeled with unknown nonlinear parameters. A parameter separation technique is introduced to transform the nonlinear parameterized system into a linear-like parameterized system. Then, by the use of input-state scaling technique and adding a power integrator backstepping approach, an adaptive state feedback controller is obtained. The adaptive control based switching strategy is proposed to eliminate the phenomenon of uncontrollability. Global asymptotic regulation of the closed-loop system states and the boundedness of other signals are guaranteed. Simulation examples demonstrate the effectiveness of the proposed scheme.     

科技论文关键词撰写探讨

以《低温与超导》为例,探讨关键词写作中的一般规律以及需要注意的事项。还给出一些提高关键词写作质量的建议。     

含嘧啶取代1,3,4-噁二唑(噻二唑)硫醚化合物的合成及抗菌活性研究

以2-甲基-4-氨基-5-氰基嘧啶为原料,通过水解、酯化、肼解、环化和醚化等步骤,合成了12个含1,3,4-噁二唑(噻二唑)取代嘧啶化合物。通过₁H NMR,₁₃C NMR,MS 和元素分析进行确证其结构。初步抑菌活性测试标明,化合物浓度在50 μg/mL时,化合物6f和6f′对油菜菌核病菌(S. sclerotiorum)、马铃薯晚疫病菌(P. infestans)、水稻纹枯病(T. cucumeris)、小麦赤霉病菌(G. zeae)具有中等抑制率,其活性与对照药剂醚菌酯相当。     

Continuity of the solution to the even logarithmic Minkowski problem in the plane

This paper investigates continuity of the solution to the even logarithmic Minkowski problem in the plane. It is shown that the weak convergence of a sequence of cone-volume measures in R~2 implies the convergence of the sequence of the corresponding origin-symmetric convex bodies in the Hausdorff metric.