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The high-temperature gas-cooled reactor pebble-bed modular (HTR-PM) has been proposed by the Institute of Nuclear and New Energy Technology of Tsinghua University, in which the active magnetic bearings (AMBs) are equipped to support the high-speed rotor in the helium circulator system. In the case of AMB failures, emergencies, or overload conditions, the auxiliary bearing is applied as the backup protector to provide temporary mechanical support and displacement constraint for the dropping rotor. A detailed dynamic model is established to reveal the behavior of the dropping rotor. This model is able to describe the rotor displacement and inclination around each axis. The left and right rotor orbits are revealed. Dropping experiments are also carried out to reveal the actual behavior of the dropping rotor in helium. The predicted and experimental results will benefit further study, design, and application of the auxiliary bearing in HTR-PM helium circulator. [ABSTRACT FROM AUTHOR]

Active magnetic bearings (AMBs) have been utilized widely to support high-speed rotors However, in the case of AMB failure, emergencies, or overload conditions the auxiliary bearing is chosen as the backup protector to provide mechanical supports and displacement constraints for the rotor. With lack of support, the auxiliary bearing will catch the dropping rotor. Accordingly, high contact forces and corresponding thermal generation due to mechanical rub are applied on the dynamic contact area. Rapid deterioration may be brought about by excessive dynamic and thermal shocks. Therefore, the auxiliary bearing must be sufficiently robust to guarantee the safety of the AMB system. Many approaches have been put forward in the literature to estimate the rotor dynamic motion, nonetheless most of them focus on the horizontal rotor drop and few consider the inclination around the horizontal plane for the vertical rotor. The main purpose of this paper is to predict the rotor dynamic behavior accurately for the vertical rotor drop case. A detailed model for the vertical rotor drop process with consideration of the .-orating inclination around x- and y-axes is proposed in this paper. Additionally, rolling and sliding friction are distinguished in the simulation scenario. This model has been applied to estimate the rotor drop process in a helium circulator system equipped with AMBs for the 10 MW high-temperature gas-cooled reactor (HTR-10). The HTR-10 has been designed and researched by the Institute of Nuclear and New Energy Technology (INET) of Tsinghua University. The auxiliary bearing is utilized to support the rotor in the helium circulator. The validity of this model is verified by the results obtained in this paper as well. This paper also provides suggestions for the further improvement of auxiliary bearing design and engineering application. [ABSTRACT FROM AUTHOR]

The auxiliary bearing is applied to provide mechanical uphold for the rotational dropping rotor when contact event happens due to the active magnetic bearing (AMB) failure emergencies. During the rotor drop process, the auxiliary bearing will endure huge impact force and friction heat generation. The thermal behavior will affect the mechanical interaction and dynamic behavior of the auxiliary bearing and even induce rapid failure especially when excessive temperature growth occurs. The Institute of Nuclear and New Energy Technology (INET) of Tsinghua University in China has proposed the 10 MW high-temperature gas-cooled reactor (HTR-10). It is designed to guarantee the inherent safety and economic competitiveness. The dry-lubricated ceramic auxiliary bearing is utilized to protect the AMB and aims to ensure the safety of the AMB system in the HTR-10 in the case of the special operational requirements in the reactor. This paper simulates the process of the rotor drop on the auxiliary bearings in the AMB system of the helium blower of the HTR-10, including the analysis of thermal growth based on the Hertzian contact model and a one-dimensional (1D) thermal heat transfer network model. The study results demonstrate the validation of the bearing models and elucidate different responses between mechanical and ceramic auxiliary bearings during contact events. The research in this paper offers important theoretical bases for the auxiliary bearing design to guarantee the safety of the whole system. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, a trust model based on real-time behavior detection scheme was proposed in P2P file-sharing system. It solved the problems in computing trust value only by past performances and choosing service nodes improperly. It took real-time behavior detection both in trust computing and service choosing, improving the accuracy of the trust value and the rationality in service nodes choosing. The experimental results proved the advantage of this scheme. [Copyright &y& Elsevier]

Abstract: CPN is one kind of formal modeling technique used in the behavior description of concurrent and distributed systems. It can analyze the network protocol behavior and performance well and can discover certain hidden errors. In this paper, a CPN model for LDP label distribution protocol has been designed using CPN Tools 2.2.0. And the LDP protocol mechanism has been analyzed based on the CPN model. Finally, to verify label distribution process of the LDP protocol, extracted several typical properties of the LDP protocol under the specific configuration mode and the verification results were obtained on the several typical properties using a CTL like branching temporal logic ASKCTL formulas. [Copyright &y& Elsevier]

The article discusses a study which examined the effects of the traditional Chinese medicine called Shuyusan on rats with chronic stress-induced depression. Researchers found that Shuyusan increased 5-hydroxytryptamine, 5-hydroxyindoleacetic acid, and 5-hydroxytryptophan levels but did not affect dopamine, noradrenalin, and 3-methoxy-4-hydroxyphenylglycol expressions. It concludes that Shuyusan improved symptoms of chronic stress-induced depression.