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An automatic bearing fault diagnosis method is proposed for permanent magnet synchronous generators (PMSGs), which are widely installed in wind turbines subjected to low rotating speeds, speed fluctuations, and electrical device noise interferences. The mechanical rotating angle curve is first extracted from the phase current of a PMSG by sequentially applying a series of algorithms. The synchronous sampled vibration signal of the fault bearing is then resampled in the angular domain according to the obtained rotating phase information. Considering that the resampled vibration signal is still overwhelmed by heavy background noise, an adaptive stochastic resonance filter is applied to the resampled signal to enhance the fault indicator and facilitate bearing fault identification. Two types of fault bearings with different fault sizes in a PMSG test rig are subjected to experiments to test the effectiveness of the proposed method. The proposed method is fully automated and thus shows potential for convenient, highly efficient and in situ bearing fault diagnosis for wind turbines subjected to harsh environments.

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The East Junggar is an important part of the Central Asian Orogenic Belt (CAOB). Using in situ zircon dating and Hf isotopic analysis by LA-ICP-MS and MC-ICP-MS, respectively, a detrital zircon of 4040 Ma age was found in sedimentary sequences from the Aermantai ophiolitic mélange, East Junggar. This is the oldest age record in the East Junggar terrane, and also marks the first zircon locality in the CAOB with an age older than 4.0 Ga, which is attributed to the Hadean crust. The 4040 Ma detrital zircon has an ε Hf (t) value of-5.2 and a two-stage Hf modal age of 4474 Ma, suggesting the presence of very old (Hadean) crustal material in the source area. Beside peak ages of 446 Ma, we found four age groups of 3.6-3.1 Ga, 2.53-2.37 Ga, 1.14-0.89 Ga and 0.47-0.42 Ga from 141 effective measuring points. The age of 426±4 Ma for the five youngest detrital zircons defines the lower limit of the deposition time of sedimentary sequencess in the Aermantai ophiolitic mélange. The 0.47-0.42 Ga zircons exhibit 176 Hf/ 177 Hf ratios of 0.282156 to 0.282850, corresponding to variable ε Hf (t) values from-9.3 to 12.0 and Hf model ages from 2011 to 646 Ma. These characteristics are similar to those of the early Paleozoic igneous and gneissic zircons from the Altai, but significantly different from those of the East Junggar. Based on the material structures of felspathic greywacke, the morphology, internal texture and age distributions of dated detrital zircons, in combination with a study of the regional geological data, it is suggested that the sedimentary sequences in the Aermantai ophiolitic mélange was deposited in the Late Silurian, with the main provenance from the Altai Orogen in the north. This indicates that the early Paleozoic ocean represented by the Aermantai ophiolitic mélange was readily closed during the Late Silurian, and the northern edge of the East Junggar terrane was accreted to the Altai Orogen. The joint of them then served as a marginal orogen in the southern edge of the Siberia Paleocontinent.

The Liushuigou intermediate-basic meta-igneous complex at Guanzizhen, Tianshui area, is mainly composed of metagabbro, metagabbro diorite and metadiorite, while the Baihua basic meta-igneous complex consists mainly of pyroxenite, gabbro (gabbro diorite), diorite and quartz diorite. They form a relatively complete comagmatic evolutionary series. The geochemical characteristics of intermediate-basic igneous rocks indicate that they belong to a tholeiite suite. Their chondrite-normalized REE patterns are nearly flat and are LREE-slightly enriched type, and their primitive mantlenormalized and MORB-normalized trace element spidergrams are generally similar; the LILEs Cs, Ba, Sr, Th and U are enriched, while Rb and K and the HFSEs Nb, P, Zr, Sm, Ti and Y are depleted. All these show comagmatic evolutionary and genetic characteristics. The tectonic environment discrimination by trace element reveals that these igneous complexes formed in an island-arc setting. The Thermal Ionization Mass Spectrometry (TIMS) single-grain zircon U-Pb age for the Liushuigou intermediate-basic meta-igneous rocks in the Guanzizhen area is (507.5P3.0) Ma, representing the age of these igneous complexes, which indicates that island-arc-type magmatite rocks in the northern zone of West Qinling are Late Cambrian and also reveals that the timing of subduction of the paleo-ocean basin represented by the Guanzizhen ophiolite and resulting island-arc-type magmatic activity are probably Late Cambrian to Early Ordovician.

Abstract. A new nuclide 239pa was produced by 50MeV/u 180 bombardment of uranium. A radiochemical separation method was employed for preparing sources of 239pa. The protactinium isotope 239pa has been identified for the first time by the results observed from the decay of the 239pa and its daughter 239U.The half-life of 239pa has been determined to be 106 +30rain. The experiments were performed at HIRFL in IMP, Lanzhou, China. A new isotope 239pa was produced via multinucleon transfer reaction in which natu targets were bombarded with 50MeV/u 180 to produced target-like neutron-rich isotopes. UO2(NO3)2.6H20 powder targets of 1.32g/cm 2 were irradiated for 4h. The beam intensity, on average, was 30 enA.Following the bombardments, the irradiated targets were dissolved in 15ml of 4 Mol hydrochloric acid solution. The resulting solution was vigorously shaken for 2 min with equal volumes of 0.05 Mol PMBP in benzene at room temperature. Protactinium products were extracted from 4Mol HC1 aqueous solution into the organic phases. After the phases were separated, the organic phases were washed several times with 10 ml of 4Mol HC1 to insure good separation from impurities and uranium. The organic phases were back-extracted by 10ml of 4Mol HC1-3Mol HF aqueous solution. Finally, counting sources were prepared by precipitation with ferric hydroxide.This work was Supported by National Natural Science Foundation of China and Chinese Academy of Sciences.The measurements started about 35 min after the end of irradiation and lasted for 4h.Two different experimental arrangements were used. One was for low energy 7-ray spectrum measurements with a planar HPGe detector, in which, the spectra were measured over successive time periods. The other was carried out measuring ~, (X)-7 coincidences with a 25% GMX HPGe detector and 30% HPGe detector. Two detectors were placed face to face on both sides of the sources and the 7-ray singles events as well as 7(X)-7-t coincidence events were recorded. In each arrangement, the time sequence spectra or event spectra were recorded on magnetic disks with a PC-CAMAC Multi-parameter Data Acquisition System [l]. Altogether, four and ten separated runs were made for the first and the second experiment, respectively.It should be mentioned that although U isotopes produced in the reaction were completely discriminated against by the chemical separation, impurity radioactivities of both Zr and Hf remained in the sources after the chemical separation. Consequently, the spectra contained the corresponding y-rays in addition to those from 239U and Pa radioactive isotopes.In the first arrangement, the two strong 7-rays of 74.66 and 43.53 keV which were assigned to the 239U decay can be identified due to their known T1/2, transition energies and relative intensities[ 2] (Fig.l). The assignment of the 239pa was primarily based on the time variation of the radioactivities of its daughter 239U as shown in Fig.2. The most intense v-ray of 74.66 keV was followed carefully. A radioactive-series decay analyzing progr...