9,786 research outputs found

    Improving fruit anthocyanins in 'Cabernet Sauvignon' by shifting fruit ripening and irrigation reduction post veraison in warmer region

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    In warmer regions, forcing vines to regrow and shifting fruit ripening to the cooler portion of the growing season can increase the concentration of total fruit anthocyanins (TFA) in red winegrapes, but the effect on anthocyanin composition remains unclear. Additionally, irrigation reduction post veraison was reported to improve fruit anthocyanins in cool and temperate regions with low precipitation, whereas this response has not been previously examined in forced vines grown in dry and warm regions. Experiments were conducted with 'Cabernet Sauvignon' (Vitis vinifera L.) over two consecutive years in Fresno, California, to investigate the effect of shifting fruit ripening on the concentration and composition of fruit anthocyanins as well as the influence of post-veraison irrigation reduction on fruit anthocyanins of forced vines. Vines under conventional practices (non-forced) were used as the control. Forcing treatment included removing primary leaves, clusters, and laterals, as well as hedging primary shoots, in mid-June. Control vines were irrigated at 80 % crop evapotranspiration (ETC) post veraison, whereas forced vines were irrigated at 40, 60, 80, or 100 % ETC post veraison. Results suggest that forcing vines to regrow and shifting fruit ripening led to a significant increase of TFA, primarily non-acylated anthocyanins, during fruit ripening and at harvest over two years. Forcing treatment also altered composition of fruit anthocyanins at harvest, with increased proportions of TFA comprised by the glucosides of delphinidin and petunidin but the decreased proportion of the glucosides of malvidin. This study demonstrates that forcing vines to regrow and shifting fruit ripening in the warmer region can lead to a more balanced profile of fruit anthocyanins, with improved non-acylated derivatives and altered relative abundance of the glucosides of five anthocyanidins. Reducing irrigation post veraison, however, had only a minor effect on fruit anthocyanins in forced vines

    An adaptive envelope analysis in a wireless sensor network for bearing fault diagnosis using fast kurtogram algorithm

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    This paper proposes a scheme to improve the performance of applying envelope analysis in a wireless sensor network for bearing fault diagnosis. The fast kurtogram is realized on the host computer for determining an optimum band-pass filter for the envelope analysis that is implemented on the wireless sensor node to extract the low frequency fault information. Therefore, the vibration signal can be monitored over the bandwidth limited wireless sensor network with both intelligence and real-time performance. Test results have proved that the diagnostic information for different bearing faults can be successfully extracted using the optimum band-pass filter

    Westernization or Localization? The (Mis)reading of “the Tragic” in Modern Chinese Literary Discourse

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    This paper examines the features and causal factors in constructing an idea of the tragic in modern Chinese literary discourse. It attempts at revisiting and reproducing the realities of misreading and variation upon modern Chinese introduction of the term “tragedy” (beiju) at different socio-historical periods, and has observed the interplay between two trends, namely, Westernization and localization, through the negotiation of “the tragic” into modern Chinese literary practice. These two trends have been integrated by a political and pragmatic perspective, which dominates the formation of a modern Chinese literary discourse on “the tragic”. This perspective offers both possibility and legitimacy for certain deliberate misreading, thus endows modern Chinese tragic tradition with unique features different from its Western models. This paper holds that modern Chinese intellectuals approached the idea of the tragic more at an instrumentalist level; they retained the connotation of the term in their attempt of Westernization, and altered and reconstructed the denotations of the term as their efforts of localization. For this reason, modern Chinese reading of “the tragic” is not so much as a pure passive acceptance as an active endeavor to deliberately misread this alien concept for the renovation of the then existing Chinese literary tradition

    Local Entanglement and quantum phase transition in spin models

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    Due to the phase interference of electromagnetic wave, one can recover the total image of one object from a small piece of holograph, which records the interference pattern of two laser light reflected from it. Similarly, the quantum superposition principle allows us to derive the global phase diagram of quantum spin models by investigating a proper local measurement. In the present paper, we study the two-site entanglement in the antifferomagnetic spin models with both spin-1/2 and 1. We show that its behaviors reveal some important information on the global properties and the quantum phase transition of these systems.Comment: 6 pages, 7 figure

    A robust fault detection method of rolling bearings using modulation signal bispectrum analysis

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    Envelope analysis is a widely used method for bearing fault detection. To obtain high detection accuracy, it is critical to select an optimal narrowband for envelope demodulation. Fast Kurtogram is an effective method for optimal narrowband selection. However, fast Kurtogram is not sufficiently robust because it is very sensitive to random noise and large aperiodic impulses which normally exist in practical application. To achieve the purpose of denoising and frequency band optimization, this paper proposes a new fault detector based on modulation signal bispectrum analysis (MSB) for bearing fault detection. As MSB results highlight the modulation effects by suppressing stationary random noise and discrete aperiodic impulses, the detector developed using high magnitudes of MSB can provide optimal frequency bands for fault detection straightforward. Performance evaluation results using both simulated data and experimental data show that the proposed method produces more effective and robust detection results for different types of bearing faults, compared with optimal envelope analysis using fast Kurtogram

    A Novel Method to Improve the Resolution of Envelope Spectrum for Bearing Fault Diagnosis Based on a Wireless Sensor Node

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    In this paper, an accurate envelope analysis algorithm is developed for a wireless sensor node. Since envelope signals employed in condition monitoring often have narrow frequency bandwidth, the proposed algorithm down-samples and cascades the analyzed envelope signals to construct a relatively long one. Thus, a relatively higher frequency resolution can be obtained by calculating the spectrum of the cascaded signal. In addition, a 50 % overlapping scheme is applied to avoid the distortions caused by Hilbert transform based envelope calculation. The proposed method is implemented on a wireless sensor node and tested successfully for detecting an outer race fault of a rolling bearing. The results show that the frequency resolution of the envelope spectrum is improved by 8 times while the data transmission remains at a low rate

    Entanglement and quantum phase transitions

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    We examine several well known quantum spin models and categorize behavior of pairwise entanglement at quantum phase transitions. A unified picture on the connection between the entanglement and quantum phase transition is given.Comment: 4 pages, 3 figure

    A new method of accurate broken rotor bar diagnosis based on modulation signal bispectrum analysis of motor current signals

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    Motor current signature analysis (MCSA) has been an effective way of monitoring electrical machines for many years. However, inadequate accuracy in diagnosing incipient broken rotor bars (BRB) has motivated many studies into improving this method. In this paper a modulation signal bispectrum (MSB) analysis is applied to motor currents from different broken bar cases and a new MSB based sideband estimator (MSB-SE) and sideband amplitude estimator are introduced for obtaining the amplitude at (1±2s)fs(1±2s)fs (s is the rotor slip and fsfs is the fundamental supply frequency) with high accuracy. As the MSB-SE has a good performance of noise suppression, the new estimator produces more accurate results in predicting the number of BRB, compared with conventional power spectrum analysis. Moreover, the paper has also developed an improved model for motor current signals under rotor fault conditions and an effective method to decouple the BRB current which interferes with that of speed oscillations associated with BRB. These provide theoretical supports for the new estimators and clarify the issues in using conventional bispectrum analysis
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