十聚钨酸盐催化环己醇制备环己酮工艺研究

合成新型N-甲基吗啉十聚钨酸盐[Mor1,2]4W10O32,对其进行提纯、表征和催化性能研究。催化体系是以[Mor1,2]4W10O32为催化剂,30%H2O2为氧化剂,催化氧化环己醇制备环己酮。考察催化剂用量、氧化剂用量、反应温度变化和反应时间变化对环己酮产率的影响,确定最佳反应条件为:反应温度80℃、环己醇用量5mmol、催化剂用量30μmol、氧化剂H2O2用量12.5 mmol,反应时间6小时,此时环己酮产率可达到96%。     

用ADINA确定热电厂磨煤机打击轮磨损极限

利用ＡＤＩＮＡ程序计算磨损后打击轮的应力分布状态；根据强度理论，得到磨损极限，为打击轮维修提供了依据．实践证明，不超过磨损极限的打击轮修复以后可以满足使用精度要求，其使用期限与新的打击轮相同．磨损极限的确定为国家创造了经济效益     

树状功能高分子负载锡配合物的合成及其催化酮的Baeyer-Villiger氧化反应性能研究

通过固相合成方法将聚酰胺-胺树状分子担载于氯球上,对其外围分别用2,4-二羟基苯甲醛和邻羟基苯甲醛进行修饰,再与SnCl2.2H2O反应,形成配体不同的两类树状高分子锡配合物.将此类配合物用作30%的双氧水氧化酮的Baeyer-Villiger反应的非均相催化剂,具有较好的催化活性.2-金刚烷酮、环己酮、3-甲基-2-戊酮等都转化为相应的酯和内酯,底物的转化率和产物选择性均较高.对2-羟基苯甲醛、2,4-二羟基苯甲醛和邻羟基苯甲醛修饰的不同类型催化剂催化下的反应进行比较,发现配体对锡的担载量和催化活性均有不同程度的影响.其中邻羟基苯甲醛修饰的配合物因具有较高的锡担载量而具有了最佳的催化活性.此催化体系使用环境友好的低浓度双氧水为氧化剂,催化剂制备方法简单、催化反应完成时间短、催化剂在多次重复利用后活性没有明显降低,可回收和重复利用.     

Quantum dynamics of dissociative adsorption of H_2 on Ni(100) using the dynamical Lie algebraic method

A dynamical Lie algebraic method has been applied to treating the quantum dynamics of dissociative adsorption of H_2 on a static flat metal surface. An LEPS potential energy surface has been used to describe the interaction of H_2 with Ni(100) surface. The dependence of the initial state-selected dissociation probability was obtained analytically on the initial kinetic energy and time. A comparison with other theoretical calculations and experiments is made. The results show that the method can be effectively used to describe the dynamics of reactive gas-surface scattering.     

Consensus protocol for heterogeneous multi-agent systems: A Markov chain approach

This paper deals with the consensus problem for heterogeneous multi-agent systems. Different from most existing consensus protocols, we consider the consensus seeking of two types of agents, namely, active agents and passive agents. The objective is to directly control the active agents such that the states of all the agents would achieve consensus. In order to obtain a computational approach, we subtly introduce an appropriate Markov chain to cast the heterogeneous systems into a unified framework. Such a framework is helpful for tackling the constraints from passive agents. Furthermore, a sufficient and necessary condition is established to guarantee the consensus in heterogeneous multi-agent systems. Finally, simulation results are provided to verify the theoretical analysis and the effectiveness of the proposed protocol.     

Generation of minimally persistent circle formation for a multi-agent system

In this paper, two methods of generating minimally persistent circle formation are presented. The proposed methods adopt a leader-follower strategy and all followers are firstly motivated to move into the leader＇s interaction range. Based on the information about relative angle and relative distance, two numbering schemes are proposed to generate minimally persistent circle formation. Distributed control laws are also designed to maintain the desired relative distance between agents. The distinctive features of the proposed methods are as follows. First, only 2n - 3 unilateral communication links for n agents are needed during the circle formation process and thus the communication complexity can be reduced. In addition, the formation topology is kept fixed for the whole motion and achieves a self-stability property. Finally, each follower keeps a regualr interval with its neighbors and the formation converges to a uniform circle formation. Simulation results are also provided to demonstrate the effectiveness of the proposed methods.     

Synchronization of chaotic systems based on adaptive observer design

The synchronizing problem of a chaotic system is investigated based on the observer design. The nonlinear section is assumed to satisfy the Lipschitz condition. Firstly, the normal observer is designed based on the known Lipschitz constant and the results are given in linear matrix inequality (LMI) form. Then a fairly simple adaptive observer is designed with the Lipschitz constant unknown. Simulations on synchronizing the Lorenz system are investigated and the results show the validity and feasibility of our main results.     

一例多钒酸盐杂化材料的制备及高效催化烯烃环氧化

以2-(2-吡啶基)咪唑(pIM)、Co²⁺和NaVO₃为原料,在水热条件下,制备了新的钒氧簇化合物[Co (pIM) V₂O₆](1)。采用X射线单晶衍射、粉末X射线衍射、傅里叶变换红外光谱和元素分析等方法对化合物进行了表征。单晶解析表明,该化合物由VO₄四面体和CoO₃N₂四方锥通过氧原子共边、共角连接成二维结构。基于钒氧簇在催化氧化体系中的高效活性,1作为非均相反应的催化剂,在以H₂O₂为氧化剂的催化烯烃环氧化反应中表现出优秀的催化性能,催化剂能够多次重复使用且活性基本保持不变。此外,磁化率研究表明1中存在反铁磁相互作用。     

XeCl准分子激光诱导的氮分子多光子电离

本文采用分子束和改装过的质谱装置,进行了氯化氙准分子激光诱导的氨分子紫外光电离的研究。我们不仅在(m/e)=16,17处分别观察到NH_2~+和NH_3~+离子峰,而且还在(m/e)=18处观察到NH_4~+离子峰。为搞清各种离子特别是NH_4~+离子的产生机理,测量了各种离子产率与样品压强和激光功率的依赖关系。     

多周期多产品采购量分配优化模型

为了解决随机需求与价格折扣并存条件下的多周期多产品采购量分配问题,建立了相应的多目标混合整数随机规划模型.该模型的特点是:①模型的约束条件中兼具确定性和随机性;②通过累计需求和累计采购量表示多周期的库存持有成本;③通过约束条件方程式准确地表现随机需求和价格折扣两大假设条件.针对该模型的特殊结构,提出了一种适用的求解策略:首先,通过把机会约束转化为确定性等价类,从而将多目标混合整数随机规划模型转化为确定型多目标混合整数规划模型;然后,采用目标规划法求得问题的满意解.此外,通过应用算例说明了模型的有效性和可行性.