14,872 research outputs found

    Research on force control system of lead cathode leveler

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    The flatness of the lead cathode plate affects the electrolytic efficiency of lead and the production efficiency of the whole lead electrolytic industry. However, the dynamic response of the force control system of the leveler is slow, and the anti-interference and robustness are poor. By comparing proportion integration differentiation (PID) control and feedback linearized synovial control two control strategies, MATLAB software was used for modeling and simulation analysis. The results show that the system with feedback linearized sliding mode control has faster response, higher precision and better robustness

    Research on force control system of lead cathode leveler

    Get PDF
    The flatness of the lead cathode plate affects the electrolytic efficiency of lead and the production efficiency of the whole lead electrolytic industry. However, the dynamic response of the force control system of the leveler is slow, and the anti-interference and robustness are poor. By comparing proportion integration differentiation (PID) control and feedback linearized synovial control two control strategies, MATLAB software was used for modeling and simulation analysis. The results show that the system with feedback linearized sliding mode control has faster response, higher precision and better robustness

    Combining multitemporal optical and SAR data for LAI imputation with BiLSTM network

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    The Leaf Area Index (LAI) is vital for predicting winter wheat yield. Acquisition of crop conditions via Sentinel-2 remote sensing images can be hindered by persistent clouds, affecting yield predictions. Synthetic Aperture Radar (SAR) provides all-weather imagery, and the ratio between its cross- and co-polarized channels (C-band) shows a high correlation with time series LAI over winter wheat regions. This study evaluates the use of time series Sentinel-1 VH/VV for LAI imputation, aiming to increase spatial-temporal density. We utilize a bidirectional LSTM (BiLSTM) network to impute time series LAI and use half mean squared error for each time step as the loss function. We trained models on data from southern Germany and the North China Plain using only LAI data generated by Sentinel-1 VH/VV and Sentinel-2. Experimental results show BiLSTM outperforms traditional regression methods, capturing nonlinear dynamics between multiple time series. It proves robust in various growing conditions and is effective even with limited Sentinel-2 images. BiLSTM's performance surpasses that of LSTM, particularly over the senescence period. Therefore, BiLSTM can be used to impute LAI with time-series Sentinel-1 VH/VV and Sentinel-2 data, and this method could be applied to other time-series imputation issues

    An analysis of the X-ray emission from the supernova remnant 3C397

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    The ASCA SIS and the ROSAT PSPC spectral data of the SNR 3C397 are analysed with a two-component non-equilibrium ionization model. Besides, the ASCA SIS0 and SIS1 spectra are also fitted simultaneously in an equilibrium case. The resulting values of the hydrogen column density yield a distance of \sim8\kpc to 3C397. It is found that the hard X-ray emission, containing S and Fe Kα\alpha lines, arises primarily from the hot component, while most of the soft emission, composed mainly of Mg, Si, Fe L lines, and continuum, is produced by the cool component. The emission measures suggest that the remnant evolves in a cloudy medium and imply that the supernova progenitor might not be a massive early-type star. The cool component is approaching ionization equilibrium. The ages estimated from the ionization parameters and dynamics are all much greater than the previous determination. We restore the X-ray maps using the ASCA SIS data and compare them with the ROSAT HRI and the NRAO VLA Sky Survey (NVSS) 20 cm maps. The morphology with two bright concentrations suggests a bipolar remnant encountering a denser medium in the west.Comment: 20 pages, aasms4.sty, 3 figures To appear in ApJ (1999

    Molybdenum Evidence for Inherited Planetary Scale Isotope Heterogeneity of the Protosolar Nebula

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    Isotope anomalies provide important information about early solar system evolution. Here we report molybdenum isotope abundances determined in samples of various meteorite classes. There is no fractionation of molybdenum isotopes in our sample set within 0.1 permil and no contribution from the extinct radionuclide 97Tc at mass 97 (97Tc/92Mo<3E-6). Instead, we observe clear anomalies in bulk iron meteorites, mesosiderites, pallasites, and chondrites characterized by a coupled excess in p- and r- or a mirror deficit in s-process nuclides (Mo-HL). This large scale isotope heterogeneity of the solar system observed for molybdenum must have been inherited from the interstellar environment where the sun was born, illustrating the concept of ``cosmic chemical memory''. The presence of molybdenum anomalies is used to discuss the filiation between planetesimals.Comment: 7 pages, 2 figures, 1 table, accepted in Ap

    Bell violation versus geometric measure of quantum discord and their dynamical behavior

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    Motivated by recent numerous works on the interplay among various measures of quantum correlations, we aim to investigate the relationship between the violation of Clauser-Horne-Shimony-Holt (CHSH) Bell inequality and geometric measure of quantum discord for two-qubit systems. Exact lower and upper bounds of Bell violation versus geometric discord are obtained for a specific and significant class of states, Bell diagonal states, and the respective states which suffice those bounds are also characterized. The dynamical behavior of these two quantifiers is carefully analyzed in the presence of decoherence, including Markovian, non-Markovian, and non-back-action quantum environments. The results suggest that Bell violation is closely related to geometric discord, like its relationship with other entanglement monotones.Comment: Published version. 9 pages, 16 figure
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