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The flat design of security and stability control system (SSCS) can realize the information interaction between each control sub-station and each sub-grid,which is conducive to reducing the number of SSCS layers and improving its reliability,thus increasing the difficulty of searching the control paths and differentiating the vulnerable components. The bidirectional/loop communication channels are added to the tree-shape SSCS to reduce the intermediate stations and find all the paths from the top to bottom stations based on the adjacent matrix. Considering availability of components and controllable capacity of underlying stations,the control capability of the flat SSCS is newly quantified. Average control ability and average associated path number are defined to evaluate the influence of flattening on the control ability of each station. Analytical sensitivity model of the control capability of flat SSCS with respect to the components' availability is proposed to determine the vulnerable components. The numerical analysis shows that the flat design reduces levels and intermediate stations,and improves the controllability of the SSCS. The impact on the controllability of the SSCS increases by the number of paths and controllable power,but decreases by the number of layers.

Located on the southeastern periphery of the Tibetan Plateau, the Xianshuihe fault (XSHF) is an active left-lateral strike-slip fault renowned for its frequent and intensive seismic activities. This highlights the necessity of employing advanced geodetic methodologies to precisely evaluate the fault kinematics and seismic hazard potential along this fault. Among these techniques, interferometric synthetic aperture radar (InSAR) stands out for its high spatial resolution and regular revisit intervals, enabling accurate mapping of interseismic deformation associated with fault motion. However, the precision of InSAR in measuring deformation encounters several challenges, particularly artifacts stemming from phase unwrapping errors and atmospheric phase delays. In this study, we utilize ascending and descending Sentinel-1 InSAR images spanning from January 2017 to January 2023 to drive the line-of-sight (LOS) mean crustal velocities associated with the XSHF with emphasis on phase unwrapping errors and atmospheric delay corrections. Then, the reliability of the derived LOS velocities is assessed using independent observations from the Global Navigation Satellite System (GNSS). The inferred fault slip rate along the XSHF shows significant along-strike variations, gradually decreasing from ~11.1 mm/yr at the Luhuo section to ~6.6 mm/yr at the Kangding section and then sharply increasing to ~13.0 mm/yr towards its eastern terminus at the Moxi section. The fault locking depth shows similar along-strike variations, decreasing from ~19.5 km in the northwestern part to ~4.8 km at the Kangding section, before increasing to 19.6 km at the Moxi segment. Notably, apparent surface fault creeping, characterized by a slip rate of ~2.7 mm/yr, is observed at the Kangding segment, likely resulting from postseismic slip following the 2014 Mw 6.3 Kangding earthquake. [ABSTRACT FROM AUTHOR]

Herein, a concise, effective, and scalable strategy is reported that the introduction of polar molecules (PMs) (e.g., anisole (PhOMe), phenetole (PhOEt), 2‐methoxynaphthalene (NaphOMe), thioanisole (PhSMe), and N,N‐dimethylaniline (PhNMe2)) as continuously coordinated neutral ligand of cationic active species in situ generated from the constrain‐geometry‐configuration–type rare‐earth metal complexes A–F/AliBu3/[Ph3C][B(C6F5)4] ternary systems can easily switch the regio‐ and stereoselectivity of the polymerization of conjugated dienes (CDs, including 2‐subsituted CDs such as isoprene (IP) and myrcene (MY), 1,2‐disubstituted CD ocimene (OC), and 1‐substituted polar CD 1‐(para‐methoxyphenyl)‐1,3‐butadiene (p‐MOPB)) from poor selectivities to high selectivities (for IP and MY: 3,4‐selectivity up to 99%; for OC: trans‐1,2‐selectivity up to 93% (mm up to 90%); for p‐MOPB: 3,4‐syndioselectivity (3,4‐ up to 99%, rrrr up to 96%)). DFT calculations explain the continuous coordination roles of PMs on the regulation of the regio‐ and stereoselectivity of the polymerization of CDs. In comparison with the traditional strategies, this strategy by adding some common PMs is easier and more convenient, decreasing the synthetic cost and complex operation of new metal catalyst and cocatalyst. Such regio‐ and stereoselective regulation method by using PMs is not reported for the coordination polymerization of olefins catalyzed by rare‐earth metal and early transition metal complexes. [ABSTRACT FROM AUTHOR]

The Pamir, situated in central Asia, is a result of the ongoing northward advance of the Indian continent, leading to compression of the Asian landmass. While geodetic and seismic data typically indicate that the most significant deformation in Pamir is along its northern boundary, an Mw 7.2 earthquake on 7 December 2015 and an Mw 6.8 earthquake on 23 February 2023 have occurred in the remote interior of Pamir. These two Mw ≥ 6.5 earthquakes, with good observations of satellite synthetic aperture radar data, provide a rare opportunity to gain insights into rupture mechanics and deformation patterns in this challenging-to-reach region. Here, we utilize spaceborne synthetic aperture radar data to determine the seismogenic faults and finite slip models for these two earthquakes. Our results reveal that the 2015 earthquake ruptured a ~88 km long, left-lateral strike-slip fault that dips to northwest. The rupture of the 2015 earthquake extended to the ground surface over a length of ~50 km with a maximum slip of ~3.5 m. In contrast, the 2023 earthquake did not rupture the ground surface, with a maximum slip of ~2.2 m estimated at a depth of ~9 km. Notably, the seismogenic fault of the 2015 earthquake does not align with the primary strand of the Sarez–Karakul fault system (SKFS), and the 2023 earthquake occurred on a previously unmapped fault. The well-determined seismogenic faults for the 2015 and 2023 earthquakes, along with the SKFS and other distributed faults in the region, suggest the existence of a wide shear zone extending from south to north within the central Pamir. [ABSTRACT FROM AUTHOR]

Three major subduction earthquakes occurred on March 20, 2012 (Mw 7.4), February 16, 2018 (Mw 7.2), and June 23, 2020 (Mw 7.4) in the southwestern coast of Mexico, which caused fatalities, casualties, considerable damage, and raised safety concerns about future seismic hazards. We use satellite geodetic observations to invert for the slip distributions of the three events and then investigate their interactions. Coulomb Failure Stress (CFS) induced by their slip both on surrounding thrust and normal faults are calculated. The positive CFS changes, along with the spatial‐temporal seismicity evolution, approximate earthquake recurrence rate and interseismic coupling, collectively indicate an increased possibility of a near‐future rupture around the areas between the 2018 and 2020 events in Oaxaca. Furthermore, there is a lowered chance of shallow coastal or offshore normal earthquakes but an increased chance of inland normal ruptures. Plain Language Summary: Large earthquakes result in stress changes, which can induce or retard regional seismic activity or even trigger other earthquakes. Therefore, understanding historical and recent earthquakes and their associated stress changes are crucial in the evaluation of future seismic hazards. One of the most popular and intuitive ways to relate past and future events is to calculate the Coulomb stress changes during an earthquake and a failure criterion can be established by considering the geometry of nearby faults and the stress changes induced by past events. This requires a detailed knowledge of the amount and direction of slip by which the main fault has slipped during its past ruptures. In this study, we use geodetic surface displacement measurements to invert for the slip distribution and the interactions of three subsequent subduction earthquakes in the southwestern coast of Mexico. We then evaluate the future seismic hazard of the region by considering Coulomb failure stress changes, spatial‐temporal regional seismic activities, historic earthquake records and approximate earthquake recurrence rate. The results show increased chances of a near‐future reverse rupture around Santa Catarina Juquila, Oaxaca and inland normal ruptures, but a lowered chance of shallow coastal or offshore normal ruptures. Key Points: Slip distribution and interactions of three recent subduction earthquakes in Mexico revealed from radar observationsIncreased probability of a near‐future major earthquake around areas between the 2018 and 2020 events in OaxacaLowered chance of shallow coastal or offshore normal earthquakes but increased chance of inland normal ruptures [ABSTRACT FROM AUTHOR]

The 2019 M w 7.1 Ridgecrest earthquake opens an opportunity to investigate how soon we can produce a reliable fault geometry and subsequently a robust source model based on high-rate Global Positioning System (GPS) data. In this study, we conduct peak ground displacement (PGD) magnitude scaling, real-time centroid moment tensor (CMT) calculation and rapid kinematic slip inversion. We conclude that a four-station PGD warning with a magnitude of M w 7.03 can be issued at 24 s after initiation of the rupture. Fast CMT inversion can initially recover the correct nodal planes at 30 s. The kinematic slip model reveals that the M w 7.1 earthquake is a predominant dextral strike-slip event with both normal and thrust components resolved. The earthquake shows a bilateral rupture with a low propagation speed of ∼2.1 km s−1 and a slip maxima of ∼4 m. The total moment is 5.18 × 1019 N m (M w 7.11). We further suggest that a reasonable source model will be available in a simulated real-time mode within 30 s after the earthquake occurring, without using full high-rate GPS waveforms. This research highlights the significance of high-rate GPS for rapid earthquake response and modelling of kinematic rupture, which is also generalized by the hypothetical real-time GPS analysis for the 2016 M w 7.8 Kaikoura earthquake and the 2010 M w 7.2 El Mayor-Cucapah earthquake. [ABSTRACT FROM AUTHOR]

Although the Papuan fold and thrust belt (PFTB) is thought to accommodate convergence between the Pacific and Australian plates, the possible strain partitioning and its kinematic controls in the region are poorly understood. On 25 February 2018, a devastating Mw 7.5 earthquake jolted the southern area of the PFTB, central Papua New Guinea. The detailed imaging of the source parameters of this large earthquake is an urgent demand for a better understanding of the tectonism in the region. Here we used spaceborne interferometric synthetic aperture radar data to carefully determine the possible ruptured faults and associated fault geometries and further estimated the detailed slip of the 2018 Mw 7.5 earthquake. We find that the earthquake involved multiple faults failure, and a four‐segment fault model can reasonably produce the complex coseismic deformation, especially the observed bimodal displacements. The earthquake was dominated by reverse fault motion, and significant slip of up to ~0.7 m was documented on faults extending at depths great than 25 km. An integrated analysis of the fracture complexities suggests that possible strain partitioning in the PFTB could be tightly coupled with regional fault geometries and lithospheric properties. Our findings on the deep brittle failures suggest that crustal shortening across the PFTB could primarily control the growth of fold and thrust belt in the central Papua New Guinea. Key Points: Complete coseismic surface deformation generated from InSAR helps determine ruptured faults and constrain the complex source parametersThe 2018 Mw 7.5 Papua New Guinea earthquake was characterized by deep‐seated reverse faulting with ruptures extending into depths of 25 kmThis event revealed the possible strain partitioning in the Papuan fold and thrust belt and can help explain its growth [ABSTRACT FROM AUTHOR]

Network slicing has been proposed as an innovative concept to partition a physical network into different configurable slices, thereby allowing the network to meet the diverse requirements of expected services in the 5G era. Existing network-slicing schemes focus almost exclusively on the partitioning of the core network or the radio access network. However, to achieve greater flexibility and better resource utilization in service provisioning, the potential of network slicing in the 5G optical mobile fronthaul (MFH) network should be jointly exploited. To address this challenge, we propose a flexible hierarchical edge cloud architecture to enable 5G optical MFH network slicing. Additionally, a corresponding integrated network resource management scheme is proposed to support various quality-of-service (QoS) requirements and diverse resource requests of the network slices. Simulation results indicate that the proposed scheme is able to jointly allocate the bandwidth resources to network slices and realize cloud-computing offloading to meet various QoS requirements, and therefore reduce the fronthaul bandwidth burden. [ABSTRACT FROM AUTHOR]

An integrated navigation scheme based on multiple optical flow sensors and a strapdown inertial navigation system (SINS) are presented, instead of the global position system (GPS) aided. Multiple optical flow sensors are mounted on a micro air vehicle (MAV) at different positions with different viewing directions for detecting optical flow around the MAV. A fault-tolerant decentralized extended Kalman filter (EKF) is performed for estimating navigation errors by fusing the inertial and optical flow measurements, which can prevent the estimation divergence caused by the failure of the optical flow sensor. Then, the estimation of navigation error is inputted into the SINS settlement process for correcting the SINS measurements. The results verify that the navigation errors of SINS can be effectively reduced (even more than 9/10). Moreover, although the sensor is in a state of failure for 400 seconds, the fault-tolerant integrated navigation system can still work properly without divergence. [ABSTRACT FROM AUTHOR]

Considering the fast time varying characteristic of pitch channel model of hypersonic model with coupling of engine, a kind of hybrid attack angle tracking controller is designed based on variable structure and Taylor type FLNN neural network method. And the adoption of variable structure control method make the system response very fast and robust. The Taylor type FLNN neural network is constructed with the format of fitting function which is used to describe the force and moment caused by attack angle, so it can compensate the interruption caused by the uncertainty and unconsidered factors effectively. At last, detailed numerical simulation is done to testify the rightness of the proposed hybrid method. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a hardware‐in‐the‐loop (HIL) simulator, named HIL‐GSS, which aims to help the students of aerospace engineering learn control and missile guidance theories effectively by using interactive instrumentation. Electromechanical components and interactive panels are illustrated. Two case‐based studies are presented to show the advantages that HIL‐GSS offers to engineering education. Steady‐state tracking errors of the PID controller based on the HIL‐GSS are around zero. The final miss distance in the real‐time HIL TV guidance engagement simulation is 0.2376 m. Those results show the reliability of the proposed HIL simulator. In addition, the students' average response to survey questions is 4.22 (1–5 grade scale), which indicates that students strongly agree or agree that HIL‐GSS is an effective educational tool. [ABSTRACT FROM AUTHOR]

As one of the most promising photocatalysts, graphitic carbon nitride (g-C3N4) shows a visible light response and great chemical stability. However, its relatively low photocatalytic efficiency is a major obstacle to actual applications. Here an effective and feasible method to dramatically increase the visible light photocatalytic efficiency by forming C3N4/BiFeO3 ferroelectric heterojunctions is reported, wherein the band alignment and piezo-/ferroelectricity have synergistic positive effects in accelerating the separation of the photogenerated carriers. At the optimum composition of 10 wt% BiFeO3, the heterojunction shows 1.4 times improved photocatalytic efficiency than that of the pure C3N4. Most importantly, mechanical pressing and electrical poling can also improve the photocatalytic efficiencies by 1.3 times and 1.8 times, respectively. The optimized photocatalytic efficiency is even comparable with that of some noble metal based compounds. These results not only prove the improved photocatalytic activity of the C3N4–ferroelectric heterojunctions, but also provide a new approach for designing high-performance photocatalysts by taking advantage of ferroelectricity. [ABSTRACT FROM AUTHOR]

Two-dimensional anatase TiO2 hollow nanoplates were firstly synthesized through a facile synthesis route by using α-Fe2O3 nanoplates as removable templates. Two-dimensional hollow TiO2 nanoplates with different ratios of anatase and rutile phases were obtained by adjusting the calcining temperature. The average diameters were around 600 nm, and the shell thickness was approximately 30 nm. The photocatalytic performance of TiO2 was investigated by decomposing rhodamine B under simulated sunlight. Among the TiO2 samples, the anatase TiO2 hollow nanoplates manifested a significant enhancement in the photocatalytic performances. The excellent catalytic performance can be attributed to the unique structure of the two-dimensional anatase TiO2 hollow nanoplates, including a large surface area and increased dye-photocatalyst contact areas as well as more active sites for photodegradation. [ABSTRACT FROM AUTHOR]

Two-dimensional nanosheets with high specific surface areas and fascinating physical and chemical properties have attracted tremendous interests because of their promising potentials in both fundamental research and practical applications. However, the problem of developing a universal strategy with a facile and cost-effective synthesis process for multi-type ultrathin 2 D nanostructures remains unresolved. Herein, we report a generalized low-temperature fabrication of scalable multi-type 2 D nanosheets including metal hydroxides (such as Ni(OH)2, Co(OH)2, Cd(OH)2, and Mg(OH)2), metal oxides (such as ZnO and Mn3O4), and layered mixed transition-metal hydroxides (Ni-Co LDH, Ni-Fe LDH, Co-Fe LDH, and Ni-Co-Fe layered ternary hydroxides) through the rational employment of a green soft-template. The synthesized crystalline inorganic nanosheets possess confined thickness, resulting in ultrahigh surface atom ratios and chemically reactive facets. Upon evaluation as electrode materials for pseudocapacitors, the Ni-Co LDH nanosheets exhibit a high specific capacitance of 1087 F g−1 at a current density of 1 A g−1, and excellent stability, with 103 % retention after 500 cycles. This strategy is facile and scalable for the production of high-quality ultrathin crystalline inorganic nanosheets, with the possibility of extension to the preparation of other complex nanosheets. [ABSTRACT FROM AUTHOR]

This letter presents a planar triple-band multiple- input-multiple-output (MIMO) antenna that meets GSM900/1800 and LTE2600 bands protocols. The antenna element contains three individual meander-line-type inverted-L radiators; the highest frequency band radiator is fed by a transmission line, while the other two utilize the proximity-coupling feeding mechanism driven by the highest band radiator. The MIMO antenna is incorporated with two symmetric triple-band antenna elements and two physical decoupling devices. The two antenna elements are closely spaced with 1/15 wavelength of the lowest band. The two decoupling devices, a T-shaped slot and a meandering microstrip-line resonator, are built for the highest and the lowest frequency bands, respectively. Meanwhile, a negligible mutual coupling effect in middle band is achieved by using a collinear-placed transverse meander-line pair in the MIMO antenna. The antenna prototype measurement results show good impedance matching with low mutual coupling effect. The calculated envelope correlation coefficient verifies the suitability of the proposed antenna for mobile wireless access applications. [ABSTRACT FROM PUBLISHER]

The article focuses on the study of agricultural wastes to produce fermentative hydrogen by optimizing incubation factors. Effects of environmental effects were determined through experimental design. Hydrogen production potential by agricultural waste was shown by anaerobic fermentation. Nutrient addition and temperature were most important tested factors for hydrogen production.

A self-starting, passively mode-locked all-fibre ring laser based on the homemade Er3+/Yb3+codoped phosphate glass fibre is reported. Dual-pump sources were used to achieve the mode-locked operation in the experiment. The fundamental mode-locked pulse repetition rate is 10.67 MHz. The pulse duration, assumed as the fit of hyperbolic secant pulse shape, is 5.82ps. We also observe the multi-pulse output of the fibre laser. [ABSTRACT FROM AUTHOR]

The M w 7.6 Chi-Chi earthquake struck central western Taiwan in 1999. The rupture was complex with several dislocations along the 100-km long Chelungpu thrust fault. Revisiting this earthquake is a challenge, as the precision and coverage of the data sets available are quite poor. Furthermore, the topographic and vegetation coverage complexity of the area prevents coherent radar images. In this paper, radar and optical images, and terrestrial geodetic measurements, were utilised to study the fault. The Particle Swarm Optimization and Okada Inversion (PSOKINV) geodetic inversion package was used with the generalized Akaike's Bayesian Information Criterion (gABIC) to precisely determine the slip distribution and relative weighting of datasets. Differences in results using the data sets jointly or separately (e.g., under-estimation due to InSAR, inconsistencies in SPOT offsets, smoother slip distribution with gABIC weighting) are observable. Most of the energy was released in the northern part of the fault, where the strike veers toward the east, and mainly at depths less than 4 km. The PSOKINV-gABIC approach is viable for the study of complicated cases such as the Chi-Chi earthquake and can significantly benefit the weight determination and physical realism of the fault geometry. [ABSTRACT FROM AUTHOR]

Rapid population growth combined with recent drought events and decades of political instability have left the residents of Kabul facing water scarcity, significantly relying on groundwater. Groundwater overexploitation might have induced various magnitudes of ground subsidence, however, to date, no comprehensive study of ground subsidence in Kabul has been conducted. In this study, we investigated the spatio-temporal evolution of ground deformation phenomena and its main governing processes in Kabul from 2014 to 2019 using C-Band Sentinel-1 derived Interferometric Synthetic Aperture Radar (InSAR) time-series from both ascending and descending orbits to extract the two-dimensional (2D) surface displacement field. Four subsidence bowls were distinguished with highly variable spatial extents and deformation magnitudes over four separate aquifer basins, with the maximum value of −5.3 cm/year observed in the Upper Kabul aquifer basin. A wavelet analysis suggests that there is a strong correlation between the groundwater level variations and subsidence. Investigation of hydrogeological data further reveals that the observed subsidence could be attributed to the presence of highly compressible clayey soils. This detailed space-borne regional survey provides new insights into the main governing mechanism of land subsidence in Kabul and may direct better mitigation plans of potential hazards. [ABSTRACT FROM AUTHOR]

The 2019 Mw 7.5 New Ireland earthquake occurred at an equatorial area where the dense vegetation prevents remote sensing techniques such as C- or X-band interferometric synthetic aperture radar (SAR) from acquiring coherent phase measurements. Therefore, in this paper, multiple remote sensing techniques including the L-band interferometric SAR, the range and azimuth offset tracking of SAR intensities, and the offset tracking of optical images were employed to map its co-seismic deformation field and to determine the slip distribution. The surface rupture was clearly and consistently captured by all offset observations, with the ground fault trace striking at an angel of 315° and extending over 10 km. An iterative weighting strategy based on the residual root mean square of inversions using individual datasets was developed to determine the relative weight of each dataset, allowing for the joint inversion of the fault geometry, the refinement of the dip angle, and the determination of the best fitting slip distribution. The resultant model indicates a nearly left-lateral strike-slip motion on the Weitin fault that ruptured to the surface with a maximum slip of 6.10 m, occurring at a depth of ~10 km, and a geodetic moment release of 1.03 × 1020 Nm, corresponding to a magnitude of Mw 7.31. The distribution of aftershocks shows about 70% of aftershocks were located in the area with increased Coulomb failure stress and few aftershocks in the subduction zone to the south of the Weitin fault were triggered by this event. [ABSTRACT FROM AUTHOR]