Nanoreactor Based on Macroporous Single Crystals of Metal‐Organic Framework

A sacrificial template strategy is developed for the synthesis of yolk–shell Au@ZIF‐8 nanoreactor. The Au@ZIF‐8 nanoreactor possesses single‐crystalline metal‐organic framework (MOF) shell with intrinsic monodisperse micropores and introduced macropores. In each of the macropores, one Au NP is encapsulated to form a nanoreactor unit. The quantity of the reactor units in the MOF shell can be readily regulated. Such structure features of the Au@ZIF‐8 nanoreactor facilitate the size selectivity of reactants, the accessibility of Au nanoparticles to reactants, and the mass transfer of reactants and products. As a result, the Au@ZIF‐8 nanoreactor delivers excellent size selectivity, enhanced conversion, and good cycling stability when used to catalyze the aerobic oxidation of alcohols with different molecular size.     

振筒式压力传感器振型跃变的理论分析与实验研究

本文从理论上分析了振筒式压力传感器敏感元件—振筒产生振型跃变的原因,说明了振筒的结构参数对其压力—频率特性的影响,提出了研究振筒振动稳定的实验方法,并给出了实验结果,从而提供了保证传感器输出频率稳定性的设计依据.     

提高DES加密强度的密钥选位方法研究

在对标准ＤＥＳ算法中密钥的选位方法进行详细分析的基础上,指出了该选位方法潜在的不足,以及在某些情况下会大幅降低ＤＥＳ算法加密强度的原因;提出了几种有助于提高ＤＥＳ加密强度的选位方法;给出了相应的密钥选位方法实现的细节和程序。     

多介质复合体界面裂纹尖端场

本语言首先介绍了双介质材料及多层介质材料同裂纹尖端场的一些概念琚结果；然后采用本语言提出了的多层介质界面裂纹分析模型，用有限元方法求得了许多数值结果，并对其进行了分析和讨论。     

The improvement of glowworm swarm optimization for continuous optimization problems

Glowworm swarm optimization (GSO) algorithm is the one of the newest nature inspired heuristics for optimization problems. In order to enhances accuracy and convergence rate of the GSO, two strategies about the movement phase of GSO are proposed. One is the greedy acceptance criteria for the glowworms update their position one-dimension by one-dimension. The other is the new movement formulas which are inspired by artificial bee colony algorithm (ABC) and particle swarm optimization (PSO). To compare and analyze the performance of our proposed improvement GSO, a number of experiments are carried out on a set of well-known benchmark global optimization problems. The effects of the parameters about the improvement algorithms are discussed by uniform design experiment. Numerical results reveal that the proposed algorithms can find better solutions when compared to classical GSO and other heuristic algorithms and are powerful search algorithms for various global optimization problems.     

Orthogonalized Fisher discriminant

The Foley-Sammon discriminant (FSD) exhibits higher performance in face recognition than the Fisher linear discriminant due to its elimination of dependences among discriminant vectors. But its theory is complex and the calculation is time expensive. The orthogonalized Fisher discriminant (OFD), which also derives a set of orthogonal discriminant vectors, is very simple and easy to implement. Experiments show that OFD is more effective and efficient than FSD in pattern recognition.     

6自由度并联机器人的结构参数对活动空间的影响

研究了６自由度并联机器人的活动空间问题。由于活动空间的边界曲线为刀具刀尖所能达到的最远点,所以根据从六条腿中一条腿达到最大长度时计算机构的位置反解,可求得其边界点。并通过实例,求得了不同截面下的活动空间的轮廓曲线。同时通过改变结构参数,进而求得这些参数对活动空间的影响,并绘制了相应的曲线。     

锂离子电池参数监测中的光纤传感技术

近年来锂离子电池安全事故频发对锂离子电池产业带来比较严重的影响,为减少此类事故发生,可采用电池管理系统对锂离子电池进行安全管理,保证其正常运作。管理过程中利用传感器对电池参数进行监测十分必要,光纤传感器具有体积小、抗电磁干扰能力强、可分布式测量等优势,可实现对锂离子电池的精准监测。文章从锂离子电池监测需求出发,简要介绍了三种主流光纤传感原理,并综述了各种用于锂离子电池监测的光纤传感最新研究成果,最后对光纤传感技术在锂离子电池参数监测中的应用做了展望。     

桥塞卡瓦坐封下套管磨损机制研究

在油田开发中桥塞是主要井下工具之一,在不同的密封压差下,不同材料的桥塞卡瓦对套管产生不同的损伤。在SRV型摩擦磨损试验机上进行卡瓦磨损套管试验,并利用扫描电子显微镜(SEM)和X射线能谱仪(EDAX)对套管磨损表面的形貌及元素成分进行分析。结果表明:套管的磨损性能与载荷和接触的卡瓦材料有关;随着卡瓦材料的硬度和载荷的增加,套管的磨损加重;在重载荷作用下,套管磨损机制主要为接触疲劳磨损、黏着磨损和磨粒磨损,表面犁沟现象明显。     

普通离子液体润滑剂的润滑成膜性能研究

目前离子液体在机械润滑研究领域受到重视,但对离子液体润滑成膜能力的研究还不多.利用纳米级膜厚测量仪考察几种具有不同阳离子侧链长度的普通磷酸盐离子液体在不同压力下的成膜能力,同时利用相近粘度的硅油作为对比对象,探讨离子液体的润滑失效及抗压能力.结果表明,在卷吸速度较高时,这几种离子液体的润滑行为符合弹流润滑规律,而在较低...