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The wind turbines have gained a wide range of applications in Renewable Energy Sources (RES) by virtue of its dominant advantages, and it has achieved almost the state-of-the-art from the engineering point of view. Nevertheless, the starting behavior which plays a prominent role in wind power generation has achieved few studies up to this moment. We conducted this analysis of a micro horizontal axis wind turbine (MHAWT) on its starting behavior to give insight into its start-up torque as well as its start-up speed on an assumption that it is rigid body, and some relative simplification on its structure are adopted meanwhile. The wind turbine's power coefficient CP, tip-speed-ratio l along with torque coefficient CT were taken into consideration and discussed to a large extent in order to having a relative clear cognition of its operational characteristics.

Aluminum titanate (Al2TiO5) film was prepared via sol-gel method at low temperature, using ethyl acetoacetate and anhydrous citric acid as compound chelating agent, tetrabutyl titanate (Ti (OC4H9)4) and aluminum chloride (AlCl3.6H2O) as precursors, ethanol as solvent. The phase transformation of Al2TiO5 xerogel during heat treatment, the effect of different chelating agents on the synthesis of Al2TiO5, and the phase composition and morphology of film were investigated by means of differential thermal and thermo gravimetric analysis (DTA-TG), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR) and field-emission scanning electron microscopy (FE-SEM). The results demonstrate that Al2TiO5 can be synthesized at 750 °C by using compound chelating agent, rather than single chelating agent. Compound chelating agent contributes to the formation of Al-O-Ti heterogeneous bond, which is the key to preparing Al2TiO5 at low temperature. High quality Al2TiO5 film could be coated on the SiC substract at 750°C.

Low energy sedimentary environment with weak water power and high salinity of formation water are the main requirements of low-resistance oil layer development. Whereas part of formation penetrated by hydrocarbon migration, which shows larger bend degrees of conductive tunnels in formation and higher resistivity measurement due to the oxidization of the residual crude oil, forms high-resistance water layer. Because of the complexity of accumulation conditions, these two difficult reservoirs exist in Putaohua reservoir of Weixing oilfield widely. Combined with these accumulation regularities, this paper analyzes and summarizes the complex oil and water distribution characteristics, provide recognition means, so as to enhance the logging evaluation precision of these two difficult reservoirs effectively.

Ants System is one bionic algorithm developed in recent years, lacking rigorous theoretical instructions. In this paper, studies on the properties of Ants System are made and several parameters concerned, include: ant initial number m、transfer control parameter q0、importance of visibility β and stigmergy decay parameter , are analyzed, which is of reference significance.

The compound of perylene-3,4,9,10-tetracarboxylic acid (PTCA) has been synthesized and characterized. By varying the concentration, it can be used to modulate the supramolecular self-assembly morphologies. Atom force microscopy (AFM) images show that the nano-layer structure will be obtained in relatively high concentration. This structure mainly depends on the intermolecular hydrogen-bonding and π–π stacking interactions.

The formation of helical nanostructure is investigated for donor/acceptor system. The helices of the supramolecular nanofibres can be revealed by atom force microscope (AFM) and circular dichroism (CD) measurement. The expermental results show the Py-Per-Py can self assembly into helical nanofibres. The controlled experiments on the compound Py-e-Per-e-Py with symmetrical conformation indicates the formation of helical nanofibres may be attributed to asymmetrical conformation.

The difficulty of measuring the run-out of engine valve seat related to the centerline of the valve guide is the determination of the datum axis. A method that the gauge was fixed on the conical surface of the valve seat was chosen. One sensor on the conical surface of the gauge measures the run-out of the valve seat related to the centerline of the gauge. Another two sensors of the gauge measures the centerline of the valve guide. The mathematic model of measurement is established, the run-out of the valve seat related to the centerline of the valve guide can be archived.

There is no literature mentioned the modeling of the microstructures subjected to traveling electrostatic forces. This paper is the first time to present an analytical approach to investigate the dynamics of a micro-ring structure driven by the traveling bias voltage. The traveling electrostatic forces may come from the sequentially-actuated actuating electrodes arranged around the flexible ring. A linearized distributed model considering the electromechanical coupling effect is derived based on the small deflection assumption. According to the analytical results, the stiffness of the micro-ring will be softened periodically with the traveling speed of the driving voltage and the variation increases with the increasing of the voltage.

The electronic or pneumatic multi-section and multi-probe gauges are widely used for diameter and coaxiality measurements due to their high measurement efficiency in workshops. However, their measurement accuracy is determined mainly by the manufacturing errors of the assembly coaxiality master, therefore, how to establish coaxiality measurement datum reference is the key technology. The physical coaxiality masters are expected to be the impossible "zero error datum reference". The higher manufacturing accuracy of the masters, the more expensive for their manufacturing costs. A novel mathematical method on the basis of error separation principle was proposed in order to separate the manufacturing errors of the master. The basic principle is that the eccentric error of the coaxiality master can be expressed as the first harmonic function and the ideal zero-error datum reference could be established by the mathematical method of two sampling operations in phase difference of 180° in coaxiality master for gauge initialization. This method can be called as "mathematical datum reference" for coaxiality measurement. Experimental results indicate that the coaxiality measurement results of the multi-section and multi-probe gauge by the novel mathematical method coincide with those of the three-coordinate measuring machine and the maximum difference of both is about 0.0014 mm. The new coaxiality measurement principle can separate the datum error of the coaxiality master theoretically and can improve the coaxiality measurement accuracy greatly with the common accuracy coaxiality master.

This paper proposes a new reliability modeling and analysis approach based on Stochastic Petri Nets by employing the logical relations in the RBD to cope with the inadequacy in various quantitative reliability analysis techniques, such as Reliability Block Diagram (RBD) and Markov analysis of control system in process industry. In this paper, the proposed new approach is elaborated and its feasibility and effectiveness is illustrated in a study case. As the results show, the proposed approach is demonstrated more straightforward and visual than Markov method. This research also bears significance in its application in the reliability analysis of general system in process industry.

Given the existing difficulties in conventional reliability models and the limitations of the current SPN software tools in terms of modeling system reliability, a software tool for modeling system reliability based on SPN named RelSPN@zer is developed, describing both the general structure and the underlying numerical methods of the tool. RelSPN@zer provides a unified framework for the modeling and evaluation of SPN running under MATLAB environment and is especially tailed to the system reliability analysis. Many metrics of system reliability can be obtained both under stationary and transient state. An example is given to illustrate the use of this package.

An innovative nuisance trip calculation method based on Markov model was proposed in this paper which was used to evaluate the effect of repairment on system reliability. By analysis of the availabilities of classic 1 out of 2 (1oo2) repairable system, a new definition of spurious trip was put forwarded where online repair was considered. Compared with the benefits obtained by online repairment, the repair-caused-nuisance-trip was analyzed in this paper. Numerical calculation revealed that the online repair is helpful for anti-spurious trip in 1oo2 redundant system. Dangerous failures, if not repaired or cannot be online fixed, have complex influence on system reliability. The dangerous failure is sometimes benefit for anti-spurious performance if it is not repaired. But Mean Time To Failure Spurious (MTTFs) reduces with the increase of dangerous failure provided that dangerous failure rate is bigger than safe failure rate. Meanwhile, the finding that common cause can reduce the chance of nuisance trip was also proposed in this paper, though the influence is too small to be neglected.

The quantitative analysis of “domino” effects is one of the main aspects of hazard assessment in chemical industrial park. This paper demonstrates the application of heterogeneous stochastic Petri net modeling techniques to the quantitative assessment of the probabilities of domino effects of major accidents in chemical industrial park. First, five events are included in the domino effect models of major accidents: pool fire, explosion, boiling liquid expanding vapour explosion (BLEVE) giving rise to a fragment, jet fire and delayed explosion of a vapour cloud. Then, the domino effect models are converted into Generalized Stochastic Petri net (GSPN) in which the probability of the domino effect is calculated automatically. The Stochastic Petri nets’ models, which are state-space based ones, increase the modeling flexibility but create the state-space explosion problems. Finally, in order to alleviate the state-space explosion problems of GSPN models, this paper employs Stochastic Wellformed Net (SWN), a particular class of High-Level (colored) SPN. To conduct a case study on a chemical industrial park, the probability of domino effects of major accidents is calculated by using the GSPN model and SWN model in this paper.

The ability of executing assigned function of repairable system under certain condition is quite different from that of single unit due to redundant configuration. It is well understood that proper management strategy can greatly prolong the mean time to failure (MTTF) of repairable system. By introducing operating cycle or partial test interval, repair time and maintenance efficiency, the MTTF of classic 1oo1, 1oo2 and 2oo3 redundant systems is studied in this paper. It is found that periodical maintenance can dramatically improve the availability of repairable system, while the efficiency of maintenance has great influence on the MTTF of repairable system.