This study examines fractures in the Gaosong ore field to determine the main factors affecting the spatial variability in the fracture structure. The attributes of fractures, including the fracture ...orientation, intensity and intersection density, in the Wuzishan anticline and near the Lotus mountain fault in the Gaosong ore field in the GeJiu ore district were extracted by using a modified circular scanning line method. The fracture intensity and intersection density were analyzed based on the semivariance geostatistics function by using the volume of variation and the amount of relative variability. These parameters quantitatively describe the spatial variability in the fracture structure. The mean and standard variance of fracture intensity and intersection density in the ore field decrease with distance from the Lotus mountain fault, while the coefficient of variation increases. The spatial anisotropy is closely related to the axial direction of the Wuzishan anticline and the orientation of the Lotus mountain fault. The main factors affecting the spatial variability in the fault structure can be determined with the semivariance geostatistics function, and the results are useful for studying the geology of the mining area and can help to construct an accurate structural model to serve the needs of mine production.
Motivated by wide utilizations of the smart material actuator-based motion control systems in soft robotics, this article proposes a neural adaptive fractional-order backstepping indirect inverse ...control (NAFBIIC) scheme for a class of fractional-order hysteretic nonlinear time-delay systems with the following features: 1) The effective control for the fractional-order hysteretic nonlinear system without constructing the direct hysteresis inverse model is realized. Then, the hysteresis indirect inverse compensator for fractional-order hysteretic nonlinear systems is designed. This makes the construction of the direct hysteresis inverse model to be not required any more and the hysteresis in the fractional-order nonlinear systems is effectively mitigated. 2) The time-delay functions are approximated by combining the finite covering lemma with neural networks, which leads to the abandonment of the traditional Lyapunov-Krasoviskii functions when dealing with time-delay functions. 3) The fractional-order model of piezoelectric positioning stage is proposed, and the motion control experiments are implemented to show the effectiveness of the proposed fractional-order indirect inverse control scheme.
Abstract
To enhance the stability of the Buck converter and the capacity of resisting disturbance of the controller and converter, come up with an adaptive dynamic surface control strategy based on ...voltage mode control, which improves the ability of the energy storage system to stabilize the output voltage when the input voltage or load changes. The Radial Basis Function (RBF) neural network is combined with the finite covering lemma to approximate the unknown nonlinear functions with time-delay in the system. The error conversion and performance functions are adopted to ensure the tracking performance index. The adaptive dynamic surface controller is applied to ensure the stability of the output voltage of the system when the external conditions change. The proposed control method is tested on the hardware-in-the-loop (HIL) experimental platform. The consequence illustrate that the designed controller is feasible and has good voltage stability performance.
Abstract Submarine cable is an important equipment for data communication and power transmission in power systems, which has a complex laying environment. According to its structure, submarine cables ...can be divided into two types, single-core cables and three-core cables. In practical engineering, cable selection is crucial to ensure the safe and stable operation of the cable and reduce the cost. The present work compares the ampacity of 500 kV single-core cable and three-core cable with the same conductor cross-section area under certain laying conditions. And the temperature rise situation of the three-core cable and the single-core cable is compared under the application of the same current. The results reveals that the ampacity of the three-core cable is less than one-core cable under certain laying situations. And the maximum ampacity reduction of the three-core cable is 28.96%. Furthermore, the highest temperature rise point of the three-core cable is the air section of the J-tube, and the maximum temperature reaches 130.07°C.
The proposed income distribution effect of financial liberalization has gradually attracted the attention of academic economists, but the research results are inconsistent and even contradictory. ...This paper presents a quantitative review of these studies. The objectives are to assess the impact of financial liberalization on income inequality and to identify the sources of heterogeneity. A meta-analysis is performed with 23 empirical cross-country studies on the relationship between financial liberalization and income inequality, yielding a total of 556 estimates. We find overall support for the small negative relationship between financial liberalization and income inequality when considering potential publication bias and method heterogeneity. Our results suggest that different impact channels, institutional quality, the measurement used for financial liberalization and income inequality, and the use of different econometric methods are especially effective for explaining the differences in past study findings.
•Quantitatively synthesize the results of previous studies in meta-analysis method.•There is small negative relationship between financial liberalization and income inequality.•The impact channels with the shape of institutions are crucial when determining the effect of financial liberalization on income inequality.•There is a threshold effect in financial development and economic development channels.•The developing countries benefit more from financial liberalization and financial reform.
Abstract
MicroRNAs (miRNAs) are noncoding RNAs with 18–26 nucleotides; they pair with target mRNAs to regulate gene expression and produce significant changes in various physiological and ...pathological processes. In recent years, the interaction between miRNAs and their target genes has become one of the mainstream directions for drug development. As a large-scale biological database that mainly provides miRNA–target interactions (MTIs) verified by biological experiments, miRTarBase has undergone five revisions and enhancements. The database has accumulated >2 200 449 verified MTIs from 13 389 manually curated articles and CLIP-seq data. An optimized scoring system is adopted to enhance this update’s critical recognition of MTI-related articles and corresponding disease information. In addition, single-nucleotide polymorphisms and disease-related variants related to the binding efficiency of miRNA and target were characterized in miRNAs and gene 3′ untranslated regions. miRNA expression profiles across extracellular vesicles, blood and different tissues, including exosomal miRNAs and tissue-specific miRNAs, were integrated to explore miRNA functions and biomarkers. For the user interface, we have classified attributes, including RNA expression, specific interaction, protein expression and biological function, for various validation experiments related to the role of miRNA. We also used seed sequence information to evaluate the binding sites of miRNA. In summary, these enhancements render miRTarBase as one of the most research-amicable MTI databases that contain comprehensive and experimentally verified annotations. The newly updated version of miRTarBase is now available at https://miRTarBase.cuhk.edu.cn/.
•The yellowing of peeled water chestnuts was catalyzed by peroxidase.•Peroxidase activity was inhibited by l-methionine.•L-methionine improved the quality by inhibiting the titratable acid ...content.•L-methionine improved the texture by inhibiting the hardness.
Yellowing and the quality (total soluble solid (TSS), titratable acid (TA), ascorbic acid (AA)) and texture decline are the main reasons for shortening the storage period of peeled water chestnuts (PWCs). The mechanism of l-methionine (L-Met) inhibiting the yellowing of PWCs and improving their quality and texture is still unknown. The goal of this study was to elucidate the mechanism of l- Met-inhibiting the yellowing of PWCs and improving their quality and texture. PWCs were treated with 0.6 %, 1.2 % and 1.8 % l-Met. The degree of yellowing, polyphenol oxidase (PPO) activity, peroxidase (POD) activity, phenylalanine lyase (PAL) activity, TSS content, TA content, AA content, texture and microorganism of PWCs were measured during storage. Compared to the control, 1.8 % l-Met-inhibited POD activity by 90.03 %, TA content by 14.55 %, and the hardness by 100.89 % on day 12. These results indicated that l-Met-decreased the yellowing by inhibiting POD activity, improved the quality by inhibiting TA content, and improved the texture by inhibiting the hardness. l-Met-can be used to prolong the storage period of PWCs.
The core‐mantle boundary (CMB) marks the most dramatic changes in physical properties within the Earth, and plays a critical role in the understanding of the Earth's dynamics. PmKP waves are seismic ...phases that reflect (m − 1) times under the CMB and are useful for studying the complex CMB structure. We present an automated workflow for detecting PmKP phases using multi‐station records from global seismic stations. We employ a novel sampling method to extract PmKP waveforms into a 2‐D matrix. Two deep neural networks are then utilized for initial phase detections and subsequent slowness validations. Numerous PmKPab (3 ≤ m ≤ 7) and their CMB diffracted signals were identified for deep earthquakes (magnitude >6) occurred from 2000 to 2020, including diffracted P7KPab waves with diffraction lengths of nearly 20°. Our approach significantly improves the efficiency of PmKP phase identification and holds the capability to detect other weak core phases, such as PKiKP.
Plain Language Summary
Seismic waves provide invaluable information about the Earth's core when sampling the core‐mantle boundary (CMB) complex structures. However, adequate sampling of this region remains a challenge due to the uneven distribution of earthquakes and seismic stations. PmKP is a seismic phase that reflects multiple times (m − 1) within the CMB, and even though it has been considered elusive, it offers an opportunity to overcome the sampling limitation caused by the earthquake‐station distribution and enhance the CMB seismic coverage. Here, we propose a new automated approach to detect unprecedent high reverberations of PmKP. Our method utilizes a combination of two deep neural networks to analyze seismic records from stations distributed globally. By applying this approach to seismic records between 2000 and 2020, we successfully detected up to six underside reflections of PmKP phases and their CMB diffracted waves. Our method enhances the efficiency of identifying PmKP phases and has the potential to be applied to other core seismic phases.
Key Points
We propose a workflow based on neural networks to detect rarely observed core seismic phases and their diffractions
Our method successfully detects PmKP up to six underside reflections on the core‐mantle boundary (CMB), increasing the seismic sampling of the CMB
The new workflow can be used for future automated identification of other rare or weak seismic phases
SUMMARY
Diffractions of PKKPab (${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$) along the core mantle boundary (CMB) have been observed well beyond its cutoff distance in recent studies, making it useful ...for improving the spatial sampling to constrain the lowermost mantle velocity structures. However, the diffractions of PKKPab waves may occur at one of the three CMB interaction points (core entry, underside reflection and exit), giving rise to uncertainties of the sampling region. Moreover, the sensitivity kernels of the non-geometrical ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$ in the lowermost mantle are difficult to obtain with classical ray theory and can be expected to be more complicated than the typical banana-doughnut shape for direct arrivals. In this study, we address these two issues by analysing the finite-frequency delay-time sensitivity kernels of the ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$ waves computed by numerical algorithms based on full-wave theory. We find that the diffraction effects for the ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$ waves are most significant near their core entry and exit regions. For a dominant period of 1 s, the estimated widths of the first Fresnel zones on the mantle side of these two areas are about 60 km. To further investigate the sensitivities of ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$ to different structures in the lowermost mantle, we conduct a series of 1D and 2D high-frequency (∼1 Hz) modelling experiments. Our results show that the travel times and amplitudes of the ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$ waves are sensitive to large-scale P-wave anomalies (with Vp perturbations of ± 2 per cent and thicknesses of more than 100 km) and small-scale ultra-low velocity zones (ULVZs; with Vp reduction of 5 per cent or 10 per cent and thickness of tens of kilometers). However, the slownesses of the ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}\ $ waves remain nearly unchanged in the perturbed models. We explain this unexpected result by the differential delay-time sensitivity kernels for stations at similar epicentral distances. Our results demonstrate both the advantages and limitations of the ${\rm{PKKP}}_{{\rm{ab}}}^{{\rm{diff}}}$ waves in studying the structures at the base of the mantle.
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