Advanced Materials Research Vols. 108-111

Abstract: The cosine-distributed impulsive loads induced by intense soft X-ray radiation are often simulated by explosive rods in laboratory tests. The conventional design method of rods distribution needs a complicated process, by trials or optimization, to ensure the rod number as an integer. This paper proposes a simplified method based on the principle of load discretization and impulse equivalence. It has higher efficiency and more convenience, and can automatically let the rod number be an integer. This study provides an effective design tool for rod-explosive simulation tests of aerospace structures under intense soft X-ray radiation.

Abstract: Pyroshock responses of aerospace structures/systems are significantly important for design and valuation of space systems because it is a harsh environment for the systems, especially the electrical components. But the designers strongly rely on tests because, up to now, there have not been effective analytical and even numerical techniques for this problem. Fortunately, a number of researchers have been making efforts to build numerical techniques for structural responses prediction under this kind of special dynamic environments. This paper presents the techniques of time-history analysis, response spectrum analysis, statistical energy analysis and a synthetic technique composed of hydrocode analysis, time-domain finite element analysis (FEA) and statistical energy analysis. Further work and development trends are discussed in the end.

Abstract: As the only still used pictographs in the world, NaXi pictographs has been used in computer information processing. However, the technology of processing minority scripts hasn't been applied on mobile platform. Using Eclipse, this paper has developed a NaXi Pictographs Mobile Phone Dictionary Based on J2ME. Via Fast Searching Algorithm of Trie tree, we achieved the goal of NaXi-Chinese query and online update of the lexicon. To the problem of display NaXi pictographs on the MT (Mobile Terminal), we extracted matrix font of NaXi pictographs. The realization of NaXi Pictographs Mobile Phone Dictionary drew a new page on the history of information processing on Chinese minority scripts mobile, as well as a great reference for information processing on other minority scripts.

Abstract: The paper firstly introduced the sensitive mechanism of micromachined airflow omnibearing level posture, and compare several sense organ’s structure schematic design, and the best structure design is proposed. At last, it is testified that the design of micromachined airflow omnibearing level postrue sensor achieved the following performances: resolution<0.1°,the scope of azimuth is 360°,the scope of tile angle is 20°. The sensor is not only in small size but also in simply crafting. It is good in sensitive organ’s output consistency, and suitable for mass production.

Abstract: The paper firstly introduced the sensitive mechanism of micromachined airflow omnibearing level posture. Adopt micro-machine technology, octagonal sense organ is sensitive to omnibearing level posture. Signal processing circuit is composed by pre-signal circuit and digital circuit, to obtain voltage, omnibearing signal synthesis and resolution compensation of omnibearing tile angle signal. It is testified that: resolution<0.1°,the scope of azimuth is 360°,the scope of tile angle is 20°. The sensor is not only in small size but also in simply crafting. It is good in sensitive organ’s output consistency,and suitable for mass production.

Abstract: Gears are key rotor components of many machines and are widely used in many engineering fields such as mining machinery, aerospace; transportation and petrochemical etc, and their failure often cause disastrous results. In practical engineering, it is still tedious to assess gears strength and the stress levels of them are very high nowadays. It is well known that the stress analysis is a basic work of age analysis and reliability analysis. Do a finite element analysis (FEA) is necessary before and after the gears have been made. In this paper, a detail analysis is done with FEA, and the stress distribution of gear is consistent with the real distribution. Also the FEA results show that the location of maximum stress is just the failure site of the gear. The analysis results are meaningful for further work such as reliability assessment and optimization design.

Abstract: The cascade correlation algorithm that is CC algorithms, CC network structure and CC network weights learning algorithm are introduced, based on the operation data of Wanjiazhai hydropower station, considering the pressure fluctuation, the network model of vibration characteristics is established based on CC algorithm, and the applications of CC and BP algorithm in vibration characteristics of turbine are compared. The results show that the CC algorithm is better than BP neural network, the results can be used in the optimal operation of hydropower, and it has a practical significance.

Abstract: On the basis of neural network based on wavelet packet-characteristic entropy(WP-CE) the author proposes a new fault diagnosis method of vibrating of hearings, in which three layers wavelet packet decomposition of the acquired vibrating signals of hearings is performed and the wavelet packet-characteristic entropy is extracted, the eigenvector of wavelet packet of the vibrating signals is constructed，and taking this eigenvector as fault sample the three layers BP neural network is trained to implement the intelligent fault diagnosis. The simulation result from the proposed method is effective and feasible.

Abstract: In order to find an effective for the disambiguation, we explore the ways of complementing statistical approaches with the use of ‘domain theories’, and suppose that disambiguation decisions can supply tacit information about such theories, and the theories can be in part automatically induced from such data. The experiment results can be used successfully in disambiguating other sentences from the same domain.

Abstract: This paper aims to collect the acoustic emission (AE), the vibration and the temperature signals produced in the hard dry milling of the die steel by using a signal collecting system based on multi-sensor and virtual instrument. Then the signals are processed by the wavelet transform and the wavelet packet transform. So we could pick up some regular pattern which could reflect the characteristic of the machining process from the results. The cutting parameters are set with single factor method and the experiment primarily focuses on researching the effect of changing the cutting parameters on the three signals mentioned forward. Through the experiment, some conclusions could be drawn as follow. In the process of the die steel’s hard dry milling, the spindle speed has a great effect on the AE signals. The temperature is mainly involved with the spindle speed and the depth of cut. The vibration signals have any clear pattern when the cutting parameter changes, but the energy of the vibration signals concentrate mostly on the first frequency band. Furthermore, the process of the hard milling is more stable.