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71.
The dispersion of nanosilica that was modified and original in organic solvents could be judged directly by using methyl red
as the indicator, and the principle of color development was also discussed. A method has been developed for the determination
of the acidity of solid surfaces, which consists of titration of the solid suspended in benzene with n-butyl amine, using neutral red as the indicator. Basic indicator forms a red color on acidic solids, and the end-point of
the titration is the disappearance of the red color.
The text was submitted by the authors in English. 相似文献
72.
Novel universal method for measurement of the condensation coefficient α is developed. Using this method, noticeable difference between measured (α≈0.8) and expected (α≈1) values of the condensation coefficient for sputtered Cr atoms was revealed for the first time. The effect is assumed to be a result of considerable elevation of the surface temperature during atomic condensation induced by the energy delivered to the condensation surface by sputtered atoms and from the plasma. 相似文献
73.
74.
Automatic feature selection for unsupervised clustering of cycle-based signals in manufacturing processes 总被引:1,自引:0,他引:1
Recent developments in sensing and computer technology have resulted in most manufacturing processes becoming a data-rich environment. A cycle-based signal refers to an analog or digital signal that is obtained during each repetition of an operation cycle in a manufacturing process. It is a very important class of in-process sensing signals for manufacturing processes because it contains extensive information on the process condition and product quality (e.g., the forming force signal in forging processes). In contrast with currently available supervised classification approaches that heavily depend on the training dataset or engineering field knowledge, this paper aims to develop an automatic feature selection method for the unsupervised clustering of cycle-base signals. First, principal component analysis is applied to the raw signals. Then a new method is proposed to select information containing principal components to allow clustering to be performed. The dimension of the problem can be significantly reduced through the use of these two steps. Finally, a model-based clustering method is applied to the selected principal components to find the clusters in the cycle-based signals. A numerical example and a real-world example of a forging process are used to illustrate the effectiveness of the proposed method. The proposed technique is an important data pre-processing technique for the monitoring and diagnostic system development using cycle-based signals for manufacturing processes. 相似文献
75.
Peng Zhou Lincoln Young Kristin Lynch 《Journal of The Association for Laboratory Automation》2003,8(5):5-10
The LabMatrix™ is a prototyping system designed to give the user a practical and versatile platform for testing microfluidic applications in the fields of health care and life sciences. The LabMatrix™ system consists of a microfluidic breadboard and cover that align and secure a series of specially designed LabMatrix™ microfluidic chips. Chips are easily arranged and rearranged into a user-defined fluidic network. The LabMatrix™ system is designed with maximum flexibility in mind, providing the user with a means to prototype a wide range of microfluidic applications in a short period. 相似文献
76.
This paper presents a hierarchical flight control system for unmanned aerial vehicles. The proposed system executes high-level mission objectives by progressively substantiating them into machine-level commands. The acquired information from various sensors is propagated back to the higher layers for reactive decision making. Each vehicle is connected via standardized wireless communication protocol for scalable multi-agent coordination. The proposed system has been successfully implemented on a number of small helicopters and validated in various applications. Results from waypoint navigation, a probabilistic pursuit-evasion game and vision-based target tracking demonstrate the potential of the proposed approach toward intelligent flying robots. 相似文献
77.
78.
Han Ho Choi Myung Jin Chung 《Automatic Control, IEEE Transactions on》1997,42(12):1740-1742
In the above mentioned paper by Mahmoud-Muthairi (ibid. vol.39 (1994)) a sufficient condition for memoryless stabilization of a class of uncertain linear systems with a variable-state delay and norm-bounded time-varying uncertainties is derived in terms of an algebraic Riccati equation. This Riccati equation depends on several free matrix variables, and a subsequent result in the paper, Theorem 2, states that failure or success of the stabilization algorithm is independent of the selection of these matrix variables. In this paper, we give a counterexample to this Theorem 2 as well as providing a fix 相似文献
79.
80.
金甦文 《天津城市建设学院学报》1997,3(3):48-52
以《建筑结构学报》为调查对象,对1991年~1996年所刊载的论文,运用引文分析法,对其引文的数量、文献类型、语种及年代分布进行了统计分析,并做出相应的评价. 相似文献