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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]

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.

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]

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]

Satellite radar imagery can record surface deformation over a wide range in both phase and amplitude formats, with Interferometric Synthetic Aperture Radar (InSAR) achieving millimetre accuracy. Based on these satellite radar observations, landslide detection at a large scale can be enhanced, which is beneficial to landslide risk assessment and disaster mitigation. However, there are still several challenges in the landslide detection with satellite radar observations. This talk presents an automated SAR-based landslide detection system under development which addresses the five main challenges of conventional InSAR for landslide detection.The first challenge is dense vegetation that affects the coherence of SAR data. The effects can be weakened by use of SAR imagery with a long wavelength (e.g. S-band or L-band), a short temporal resolution, and/or a high spatial resolution (e.g. 1 m or even higher), and/or advanced InSAR time series. The second challenge is to deal with landslides with large deformation gradients, which can be addressed by SAR offset tracking and range split-spectrum interferometry (RSSI) methods with relatively low precision. We have developed an integrated approach to combine the RSSI and conventional InSAR to capture the large surface displacements of fast-moving landslides more precisely. Atmospheric effects represent another challenge of conventional InSAR for landslide detection, especially in mountain areas. The Generic Atmospheric Correction Online Service (GACOS) developed at Newcastle University is used to reduce atmospheric effects on radar observations and simplify the following time series analysis. The fourth challenge is the impacts of SAR geometry such as shadow and layover. The impacts can be pre-analysed using a high-resolution external DEM. Since very high-resolution (VHR) DEMs are often not available whilst processing VHR radar images (e.g. 1m or higher TerraSAR-X), a machine learning approach has been developed to identify water bodies, shadow and layover areas. The geometry impacts can be weakened with the joint use of descending and ascending tracks, different tracks with different incidence angles, or radar images from different radar missions. The fifth challenge is topographic effects in areas with high buildings or steep slopes, which could easily lead to phase unwrapping errors. A baseline linear combination approach has been developed to address it. In our automated SAR-based landslide detection system under development, the GACOS-assisted InSAR time series technique is employed to delimit deformation acceleration zones and detect extremely-slow-to-slow moving landslides. SAR offset tracking and RSSI are used in parallel to capture large displacements and detect moderate-to-fast moving landslides. Machine learning algorithms are developed to automatically map post-event landslides triggered by earthquakes or heavy rains. [ABSTRACT FROM AUTHOR]

In recent years, the usage of new technologies in distributed generation is growing due to the electricity industry movement towards privatization and decentralized production of electric energy as well as competition among the new technologies. Microgrids are practical examples of the concept of decentralized production. Also, the employment of renewable energies is rapidly promoted due to the construction barriers of conventional power plants. Therefore, selecting and applying the appropriate technologies in planning and careful design of the type and capacity of generation and energy storage units are important. This paper proposed a robust model for day-ahead production scheduling of electrical and thermal units in a large-scale virtual power plant comprising a large number of distributed generation units and consumers accompanied by energy storage. To consider real conditions, the uncertainty of electrical demands is modeled by employing scenario-based analysis and probabilistic programming. So, five scenarios are created and modeled. In addition, two operation mode of a microgrid is considered connected and islanded modes. The objective function consists of total profit resulting from the daily operation of all units. The results confirm the applicability and effectiveness of the proposed model. Moreover, the total profit of the connected mode of the microgrid is about 20% more than the islanded mode, in all scenarios, and the cumulative profit cash flow of the connected mode is about 31% more than islanded mode. [ABSTRACT FROM AUTHOR]

Anode materials for sodium ion batteries (SIBs) are confronted with severe volume expansion and poor electrical conductivity. Construction of assembled structures featuring hollow interior and carbon material modification is considered as an efficient strategy to address the issues. Herein, a novel template-assisted epitaxial growth method, ingeniously exploiting lattice matching nature, is developed to fabricate hollow ordered architectures assembled by SnO 2 nanorods. SnO 2 nanorods growing along [100] direction can achieve lattice-matched epitaxial growth on (110) plane of α-Fe 2 O 3 . Driven by the lattice matching, different α-Fe 2 O 3 templates possessing different crystal plane orientations enable distinct assembly modes of SnO 2 , and four kinds of hollow ordered SnO 2 @C nanorods arrays (HONAs) with different morphologies including disc, hexahedron, dodecahedron and tetrakaidecahedron (denoted as Di-, He-, Do-, and Te-SnO 2 @C) are achieved. Benefiting from the synergy of hollow structure, carbon coating and ordered assembly structure, good structural integrity and stability and enhanced electrical conductivity are realized, resulting in impressive sodium storage performances when utilized as SIB anodes. Specifically, Te-SnO 2 @C HONAs exhibit excellent rate capability (385.6 mAh·g -1 at 2.0 A·g -1 ) and remarkable cycling stability (355.4 mAh·g -1 after 2000 cycles at 1.0 A·g -1 ). This work provides a promising route for constructing advanced SIB anode materials through epitaxial growth for rational structural design., (© 2024 Wiley‐VCH GmbH.)

To access degradable polyolefin plastic, non-alternating copolymerization of ethylene (E) and carbon monoxide (CO) for producing polyethylene (PE) with in-chain ketones is particularly appealing; however, it still presents significant challenges such as molecular weight modulation (hydrogen response) and chain endgroup control (functional terminal). In this study, we achieved hydrogen-controlled E/CO non-alternating copolymerization using late transition metal catalysts. This process results in linear PEs containing the desired non-alternating in-chain keto groups (1.0-9.3 mol%) and with tunable molecular weights ranging from 43 to 195 kDa. In this reaction, H2 serves as a chain transfer agent, modulating the polymer's molecular weight, forming unique aldehyde endgroups and eliminating usual olefinic endgroups; CO undergoes non-alternating insertion into the PE chain, resulting in a strictly non-alternating structure (> 99%) for the keto-PE. The dispersed incorporation of in-chain keto groups retains bulk properties of PE and makes PE susceptible to photodegradation, which produces significantly lower molecular weight polymers and oligomers with unambiguous vinyl and acetyl terminals., (© 2024 Wiley‐VCH GmbH.)

Functional groups and small-molecule organic matter are two key parts of coal. To explore the microscopic mechanism underlying the synergistic effect of both parts on methane adsorption, the oxygen-containing (-OH, -COOH, and -C=O) and nitrogen-containing (-NH 2 ) functional groups and two common small molecular organic matter methylbenzene and tetrahydrofuran-2-alcohol in coal are selected. The quantum chemical meta-GGA functional method is used to optimize all structures. The electrostatic potential analyses, weak interaction analyses, and theory of atoms in molecules have been used to delve further into the nature of this synergistic effect. Our results show that functional groups inhibit methane adsorption by coal molecules, and the inhibition effect is enhanced in the presence of methylbenzene. Interestingly, the synergistic effects between functional groups and small molecular organic matter are changed from inhibition to promotion after introducing tetrahydrofuran-2-alcohol, wherein -COOH has the best synergistic effect. This work not only offers a theoretical foundation for exploring the synergistic effect of small molecular organic matter and functional groups on methane adsorption by coal molecules but also lays a foundation for further research on gas prevention and extraction., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

As one of the most promising photocatalysts, graphitic carbon nitride (g-C 3 N 4 ) 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 C 3 N 4 /BiFeO 3 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% BiFeO 3 , the heterojunction shows 1.4 times improved photocatalytic efficiency than that of the pure C 3 N 4 . 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 C 3 N 4 -ferroelectric heterojunctions, but also provide a new approach for designing high-performance photocatalysts by taking advantage of ferroelectricity.

Formation of solid solutions is a good strategy to acquire materials with special properties and bring forth new type of applications or enhance the performance of currently existing devices. In this study, hollow ZnxCd1-xS nanospheres with different molar ratios were synthesized via a facile hydrothermal process. The products were fully characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and UV-vis absorption spectroscopy. It was found that the photocatalysis performance of the as-prepared samples could be enhanced by formation of ZnxCd1-xS solid solutions. In addition, their photocatalytic activities are dependent on the Zn/Cd molar ratios and nanostructures of ZnxCd1-xS solid solutions. Hollow Zn0.2Cd0.8S spheres exhibit extremely high photocatalytic activity and good re-usability, and the photocatalytic conversion of RhB reaches as high as 96% after 50 min of irradiation.

Two-dimensional anatase TiO2 hollow nanoplates were firstly synthesized through a facile synthesis route by using α-Fe2 O3 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., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

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., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)