一种协调的科技文献分类方法

科技文献之间的相互引证关系反映了一种科学交流活动,显示了科学文献之间(甚至是学科之间)的内在联系,而通过追溯文献之间的这种关系,可以改善和提高传统的基于内容的科技文献的分类的方法。论文利用有相互引证关系,有同引关系,以及有耦合关系的两篇文献一般是属于同一类的这一特点,提出了文献之间的引用相似度,同引相似度,耦合相似度这三个概念,再利用这三个概念生成了文献之间的“结构相似度”,并将它用于K-NN分类法中得出一种基于结构的分类法。最后,论文将这种基于结构的分类法和基于内容的NaveBayes分类法结合起来提出了一种新的协调分类法。     

Numerical simulations of cantilever beam response with saturation control and full modal coupling

Numerical simulations of the response of a uniform, cantilever beam subjected to a base excitation are performed. A saturation absorber is implemented to control the beam response. In previous investigations of similar configurations, the inertial and structural properties of the piezoelectric actuators have been neglected, resulting in an analytical model of a uniform beam. This investigation includes the nonuniformities in the beam properties that are introduced when piezoelectric actuators are bonded to the uniform beam. The resulting coupling between uniform, cantilever beam modes is fully included in the analytical model. It is shown that this modal coupling has a significant effect on the beam response, which is not present when modal coupling is neglected.     

非接触式叶片振测系统的叶尖定时传感器的研究

介绍了一种新型的叶尖定时传感器 ,传感器采用Y型耦合光纤与自聚焦透镜相结合 ,实现聚光照明及叶尖散射光的高效收集 ,大大提高了检测灵敏度。光源采用 4 5mW的半导体激光器 ,光电接收元件采用雪崩式光电二极管。传感器具有体积小、结构简单、成本低、安装和调节方便、测量精度高等优点。实验表明 ,该传感器对信号有良好的接收能力 ,满足涡轮机叶片高速、实时检测的要求 ,能为后续处理电路提供稳定而可靠的信号     

Further evidence of responsibility of impurities in MgO for variability in its basicity and catalytic performance in oxidative coupling of methane

Further evidence was delivered that certain impurities, which could be contained in MgO samples, might be responsible for observed variability in MgO basicity and catalytic performance in oxidative coupling of methane. The surface basicity/base strength distribution of a series of MgO samples containing or not containing Ca and Na impurities was determined by a temperature-programmed desorption of CO₂. It was revealed that samples containing Ca and Na impurities have much more medium, strong and very strong basic sites. The surface basicity of MgO samples containing added alkali or alkaline earth compounds or water was characterized by a test reaction of transformation of 2-butanol. It was confirmed that the introduction of these compounds to a pure MgO enhanced both its basicity and activity in oxidative coupling of methane.     

甲醛与甲酸甲酯的偶联反应 Ⅰ.杂多酸的催化作用

研究了４种杂多酸（磷钨酸、硅钨酸、磷钼酸和硅钼酸）对甲醛和甲酸甲酯偶联反应的催化作用；对反应条件进行了考察。结果表明，磷钨酸和硅钨酸对该反应具有较高的催化活性；而氧化性强的钼系杂多酸的活性较低。水对甲醛和甲酸甲酯的偶联反应具有不利影响。将杂多酸在３００℃进行热处理后，其活性显著增强。     

油,水二相流固耦合渗流的数学模型

为了正确模拟油藏中流体流动的动态过程，必须考虑由于注水和开采而引起的多相流体的流动、应力状态的变化和储集层变形之间复杂的相互作用。但由于这种问题的控制方程是三维非线性耦合方程，因此，很难模拟这种耦合作用。利用广义的Ｂｉｏｔ理论建立了一个完全耦合的数学模型，它描述可变形油藏中岩石变形和油水流动的这种相互作用。模型中假设岩石骨架具有弹塑性特性，流体是可压缩的。以岩石骨架位移和油水压力为未知变量所建立的控制方程，包括岩石骨架的平衡方程和流体（油、水）的连续性方程。所建立的流固耦合模型在石油工程，特别是在油藏数值模拟中有广泛的应用。参８（陈志宏摘     

Effect of the method of preparation of a Nd2O3-MgO catalyst on its efficiency in the reaction of oxidative coupling of methane

It is shown that the decomposition of a mixture of nitrates or coprecipitated carbonates or hydroxides of Mg and Nd form catalysts manifesting similar catalytic properties, while the catalyst obtained by impregnation is more active but much less selective. The mechanism of formation of the catalytically active phase and the nature of the active sites are discussed.     

液力偶合器在电动煤气鼓风机系统的应用

煤气鼓风机为适应系统煤气量的变化采用改变风机的转速来进行调节是一有效的节能方法。本文介绍了液力偶合器的结构特点、工作原理及其在煤气鼓风机系统中的应用，以实现风机的调速，并取得了明显的节能效果。     

正交矩形波导复合耦合槽特性分析

两个正交矩形波导公共宽边上偏离中心线的耦合斜槽称为复合耦合槽。考虑波导壁的厚度，根据等效原理和缝隙口面切向磁场的连续条件建立一对耦合积分方程，利用矩量法进行求解，给出复合耦合槽的谐振长度、散射参量随缝隙的倾角、偏离波导中心线距离的关系曲线     

二烷基硫代磷酸铵的捕收性能

本文研究了二烷基硫代磷酸铵（ＲＯ）２ＰＳＯＮＨ４（Ｒ＝乙基、丁基、己基、烯丙烯）系列捕收剂对非硫化矿孔雀石、锡石、赤铁矿、白铅矿、方解石和菱锌矿的浮选性能，并就药剂结构与性能关系进行了分析讨论．