In Situ FTIR Studies of CO Adsorption on Palladium Loading Zeolite Elec trode

制备载Pd的分子筛电极 ,以CO吸附为探针结合电化学原位FTIR反射光谱 ,首次发现限定在分子筛超笼中的纳米Pd微粒对CO的吸附具有增强红外吸收效应。Adsorption of CO on palladium loading zeolite el ectrode supported on Pt or GC substrate was studied by in situ MSFTIR spectrosco py.The results demonstrated that the geometry of faujasite supercages favors the formation of bridge-bonded CO species.The enhanced IR adsorption of CO adsorbe d on Pd clusters located in the supercages of zeolite has been observed for the first time,which is a new phenomenon and differs from the abnormal infrared effe cts discovered by our group and the surface enhanced infrared absorption phenome non reported in the literature.国家自然科学基金资助项目!(2 99730 35

Transition Metal Promoted ZSM-5 Catalysts for the Conversion of Dimethyl Sulfide into Methanethiol

负载过渡金属的zSM-5催化剂用于催化甲硫醚(dMS)转化成甲硫醇(MT)的反应.实验结果表明,催化剂的甲硫醚转化率提高和甲硫醇选择性降低的趋势一样,都是以下顺序:CO/zSM-5>MO/zSM-5>nI/zSM-5>W/zSM-5.表征结果表明,由于过渡金属阳离子(W6+、nI2+、CO3+、MO6+)比Al3+活泼,而改性过程中W6+、nI2+、CO3+、MO6+分别代替了部分Al3+,使得改性催化剂对dMS和MT的化学吸附作用更强.过渡金属的引入使得zSM-5总酸度增强,提高了C―S键的裂解能力,从而改进了催化转化dMS的能力.研究结果发现,在转化dMS的过程中,金属活性位和酸性位之间通过强的协同效应起作用.ZSM-5-supported transition metal catalysts were prepared and used to catalyze the conversion of dimethyl sulfide(DMS) into methanethiol(MT).Test results indicated that the activities of the catalysts for the conversion of DMS increased as follows: Co/ZSM-5>Mo/ZSM-5>Ni/ZSM-5>W/ZSM-5.The decrease in MT selectivity followed the same trend.The characterization results showed that transition metal cations(W6 +, Ni2 +, Co3 +, Mo6 +) replaced some Al3 +sites leading to more active in chemiadsorption of DMS and MT since transition metal cations are more active than Al3 +.The incorporation of transition metals into ZSM-5enhances the total acidity of ZSM-5 and increases its capacity to rupture C―S bonds.This subsequently improves its catalytic behavior in the conversion of DMS.We found that the metal active sites and closely situated acidic sites have a strong synergistic effect when converting DMS

In situ FTIR studies of CO adsorption on palladium loading zeolite electrode

Adsorption of CO on palladium loading zeolite electrode supported on Pt or GC substrate was studied by in situ MSFTIR spectroscopy. The results demonstrated that the geometry of faujasite supercages favors the formation of bridge-bonded CO species. The enhanced IR adsorption of CO adsorbed on Pd clusters located in the supercages of zeolite has been observed for the first time, which is a new phenomenon and differs from the abnormal infrared effects discovered by our group and the surface enhanced infrared absorption phenomenon reported in the literature

基于ISGMD和MED的齿轮箱早期故障特征提取

针对在强噪声背景下难以识别齿轮箱早期故障以及复合故障的问题，提出了一种改进辛几何模态分解（Improved symplectic geometry mode decomposition，ISGMD）和最小熵解卷积（Minimum entropy deconvolution，MED）相结合的故障特征提取方法。首先，将信号经最小熵解卷积预处理，突出信号中的故障冲击成分；然后，将故障增强信号通过改进辛几何模态分解自适应地分解为若干辛几何分量，并依据峭度最大准则选取峭度值最大的敏感辛几何分量；最后，对选定的敏感辛几何分量进行包络分析，从而有效地提取出齿轮箱的故障特征。通过实验，验证了该方法的有效性

微创外科手术器械末端执行器夹持力建模与分析

针对主从微创外科手术机器人同一主手控制不同手术器械在相同开合角度下的夹持力安全问题，研究了手术器械末端执行器的夹持力，建立了一种求解末端夹持力的数学模型。所建立的模型考虑了钢丝绳与导向轮之间的非线性摩擦、指部与腕部的运动耦合以及钢丝绳在导向轮上的蠕动变形对夹持力的影响，得到了在相应开合角度下电机电流与手术器械末端执行器夹持力之间的映射关系；同时，对缝合针所受夹持力进行了受力分析，得到末端执行器对缝合针的夹持力以及末端执行器对缝合针的拉拔力与电机电流之间的关系。通过Matlab对夹持力模型进行仿真研究，得到手术器械末端执行器在考虑和不考虑摩擦与变形情况下的夹持力变化曲线，特别是得到了对缝合针的夹持力和拉拔力随电流变化的曲线图。仿真结果表明，所建立的夹持力数学模型更贴近实际情况，为后续有效和安全夹持力控制提供了理论依据

Method for precisely synchronizing time of industrial wireless network on basis of prediction and compensation

本发明涉及工业无线网络技术，具体地说是一种基于预测补偿的工业无线网络高精度时间同步方法。本发明将面向工厂自动化的工业无线网络组建为基于IEEE?802.11单跳基本服务集BSS结构的星型网络；按照工业无线网络中的节点的类型和功能，设置主时钟和从时钟；主时钟端和从时钟端之间通过双向时间戳信息交互，计算当前同步周期的时间偏差值；利用当前同步周期的时间偏差值预测下一个同步周期的时间偏差值；利用预测得到的下一个同步周期的时间偏差值补偿时钟漂移，校准时钟。本发明是在充分考虑工厂自动化应用需求的前提下提出的，能够利用较少的无线通信资源实现较高的时间同步精度，达到高精度、高效、低开销且易于实现的目的

基于平行四连杆的水下牵引机下限位随动机构设计与仿真分析

波浪滑翔器是一种新型水面无人观测平台，通过水下牵引机中水翼被动摆动获取波浪能来产生前向推力。通过分析常规波浪滑翔器水下牵引机的脐带缆倾斜角造成的波浪能损失现象，设计了一种水翼摆动下限可以随脐带缆倾斜角的变化而改变的水翼摆动机构——下限位随动机构。首先，通过计算流体力学软件Fluent仿真分析了下限位随动机构对于水翼摆动角度的调节能力；其次，通过在常规水下牵引机内部加装一套平行四边形传动机构，设计了下限位随动机构原理样机，并通过搭建大型波浪模拟测试平台进行水池试验，验证了下限位随动机构原理样机的推进性能。研究表明，所提新型水翼摆动机构可以很好地提升水下牵引机的推进性能