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Abstract Understanding the determinants of biodiversity in fragmented habitats is fundamental for informing sustainable landscape development, especially in urban landscapes that substantially fragment natural habitat. However, the relative roles of landscape and habitat characteristics, as emphasized by two competing frameworks (the island biogeography theory and the habitat diversity hypothesis), in structuring species assemblages in fragmented habitats have not been fully explored. This study investigated bird assemblages at 26 habitat patches (ranging in size from 0.3 to 290.4 ha) in an urban landscape, southwest China, among which habitat type composition and woody plant species composition varied significantly. Through 14 bird surveys conducted over six breeding seasons from 2017 to 2022, we recorded 70 breeding bird species (excluding birds recorded only once and fly-overs, such as raptors, swallows and swifts), with an average of 26 ± 10 (SD) species per patch. We found that patch area had significant direct and indirect effects on bird richness, with the indirect effects mediated by habitat richness (i.e., the number of habitat types). Isolation (measured as the distance to the nearest patch), perimeter to area ratio (PAR), and woody plant richness did not significantly predict variation in bird richness. Furthermore, none of these factors significantly sorted bird species based on their functional traits. However, the overall makeup of bird assemblages was significantly associated with the specific habitat types and woody plant species present in the patches. The results suggest that neither the island biogeography theory nor the habitat diversity hypothesis can fully explain the impacts of habitat fragmentation on bird richness in our study system, with their roles primarily being linked to patch area. The findings that habitat and plant compositions were the major drivers of variation in bird assemblage composition offer valuable insights into urban planning and green initiatives. Conservation efforts should focus not only on preserving large areas, but also on preventing urban monocultures by promoting diverse habitats within those areas, contributing to the persistence of meta-communities.

The superhydrophobic scallop-like Cu6Sn5 micro/nano structure were successfully constructed on pure copper substrate by heat-induced Cu/Sn interfacial metallurgical reaction and simple chemical modification process. The microstructure, chemical composition and corrosion resistance of as-prepared samples were characterized by field emission scanning electron microscopy and X-ray photoelectron spectroscopy, etc. The results show that the averaged shear resistance strength between micro Cu6Sn5 and Cu substrate is higher than 40 MPa. After modified with myristic acid and Cu2+, copper myristate with low surface energy is formed on the armor Cu6Sn5 surface. The wetting angle of water droplets on as-modified surface is higher than 150° and its rolling angle is 7.2°. Compared with pure copper, the self corrosion current density of the samples modified by copper myristate in 3.5%NaCl(mass fraction) solution is about 1/10 of that of the samples before modification,showing better corrosion resistance. Based on the metallurgical bonding mechanism between intermetallic compounds and metal matrix, the armor formation strategy of metal materials in micro-scale by heat-induced interfacial reaction is proposed, which can successfully solve the open and key scientific problem of low mechanical stability for artificial superhydrophobic interface.

An optical camera communication (OCC) is a special type of a visible light communication that uses a complementary metal-oxide semiconductor as a receiver. However, it is difficult to apply a high-order modulation scheme to such communications because of strong intersymbol interference. In this paper, we propose and demonstrate an OCC system using an 8-color color-shift keying scheme. We used an RGB-based LED light panel as a transmitter and analyzed the properties of the rolling shutter. We discuss the demodulation process and perform bit error rate (BER) tests at different ambient illuminances and sampling positions. A net data rate of 8.64 kbps and a pixel efficiency of 3.75 pixels per bit were achieved while keeping the BER below 3.8E-3, which meets the FEC's 7% forward error correction requirement. In addition, the system shows good robustness for indoor applications.

The optical properties of electrochromic materials can change reversibly under an applied voltage. Tungsten oxide has been widely used in various fields because of its excellent electrochromic efficiency. The electrochromic films produced by W _18 O _49 nanowires and WO _3 have excellent performance. Compared with WO _3 film, the porous structure of the nanowires can make ions rapidly diffuse, provide a larger surface area for the charge transfer reaction, promote electrolyte penetration, and effectively improve the electrochromic efficiency. In this paper, a kind of electrochromic tungsten oxide thin film combining W _18 O _49 nanowires and WO _3 was prepared by combining a hydrothermal method and a tungstic acid method. The electrochromic performance of the film was improved considerably by combining the two kinds of thin films. The results show that the optical modulation amplitude is close to ideal (92.5%) and has a fast colour fading (colour 1.7 s and colour fading 1.3 s) effect, a good cycle stability, which is much better than those of the WO _3 and W _18 O _49 films. Using lithium perchlorate and PC as raw materials and polyurethane as a photocuring agent, a solid-state electrochromic device based on a tungsten oxide composite film was fabricated by capillarity. The colouring time of the device is 2 s, the fading time is 1 s, and the optical modulation amplitude is 85%.

The objective of this paper is to predict the noise radiated from submarine propellers with different control surface types (the cross- and X-type). When the propellers are free from cavitation, such as those of submarines at a diving depth, the radiated noise dominate, due to unsteady propeller forces. A well-known submarine model (DARPA SUBOFF) is taken as the computing sample. Simulations for hydrodynamics, including stern wakes and unsteady propeller forces, are carried out by using CFD (Computational Fluid Dynamics) technology, and the results are compared with the experimental data. The accuracy of the predicted noise depends on the CFD results. Comparisons between the CFD results and the experimental data are in good agreement. The CFD results are treated as dipole strengths in the linear wave theory to predict the radiated noise caused by the unsteady forces of the propeller. It is found that, when the control surface is of the X-type, the propeller inflow is more uniform, and the radiated noise can be decreased by about 5 dB compared to the cruciform control surface. [ABSTRACT FROM AUTHOR]

In the title compound, C14H11BrN2O2, the mean planes of the two benzene rings are almost parallel to each other, making a dihedral angle of 4.09 (1)°. An intramolecular O—H...N hydrogen bond occurs. In the crystal, intermolecular O—H...N and C—H...O hydrogen bonds link the molecules into a chain-like supramolecular structure.

The complete molecule of the title compound, C22H28N2O4, is generated by a crystallographic inversion centre at the mid-point of the central C—C bond. The two benzene rings are parallel to each other with a perpendicular interplanar spacing of 1.488 (2) Å. Intramolecular O—H...N hydrogen bonds generate two six-membered rings with S(6) motifs. In the crystal, weak intermolecular C—H...O hydrogen bonds link neighbouring molecules into an infinite three-dimensional network, which is further stabilized by weak C—H...π interactions.