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The development of catalysts with high activity and durability for the cathodicoxygen reduction reaction （ORR） in both alkaline and acidic media is importantfor improving the performance of the proton exchange membrane （PEM） fuelcells. This can be achieved by dispersing Pt-based alloy nanoparticles insideN-doped porous carbon frameworks. However, it still requires the developmentof a facile method towards synthesizing this unique hybrid structure. In this work,we demonstrate that N-doped carbon-stabilized PtCo nanoparticles （PtCo@NC）can be facilely synthesized via thermal decomposition of Pt-incorporatedCo-based zeolitic imidazolate framework （Pt@ZIF-67）. The thickness of the carbonframework can be optimized to enable excellent durability, in sharp contrastto a commercial Pt/C catalyst. The mass activities achieved by optimizing thethickness of the carbon framework are 0.80 and 0.82 A-mg^-1, at 0.9 V vs. RHE inalkaline and acidic electrolytes, respectively, which are nearly 8 times greaterthan those of the Pt/C. This work provides an alternative approach to low-costand high-verformance catalvsts for both alkaline and acidic fuel cells.

Fully triggering the deep-seated potential of traditional nanomaterials, such as the classic spinel family, is of paramount importance in the field of materials science, which is yet believed to heavily depend on advanced conceptual designs and synthetic strategies. Herein, a type of inorganic–organic hybrid spinel oxide is designed using a π-conjugated azobenzene single-tooth coordination method to overcome their stubborn problems of moderate activity and phase instability in electrocatalytic reactions. Taking spinel Co 3 O 4 nanocubes as a pre-catalyst, after subtle etching of the cube surfaces, some oxygen atoms in the tetrahedral Co–O coordination field are replaced and selectively linked to weakly polar azo-extended π-conjugated units ( π *–N=N– π *) via electrophilic carboxyl groups. The π-conjugation structure in Co 3 O 4 suppresses the covalency competition between the tetrahedral and octahedral Co–O coordination fields, successfully preventing the phase transition during the electrocatalytic process and improving the electrocatalytic activity and durability. This study not only expands the spinel family but also provides useful guidelines for developing advanced functional materials. Unlocking the potential of traditional nanomaterials like spinel oxides is crucial for improving the catalytic oxygen evolution reaction. Here, the authors report an inorganic–organic hybrid spinel oxide that enhances both catalytic activity and structural stability through a coordination method.

Metal nanoclusters have recently attracted extensive interest not only for fundamental scientific research, but also for practical applications. For fundamental scientific research, it is of major importance to explore the internal structure and crystallographic arrangement. Herein, we synthesize a gold nanocluster whose composition is determined to be Au 60 S 6 (SCH 2 Ph) 36 by using electrospray ionization mass spectrometry and single crystal X-ray crystallography (SCXC). SCXC also reveals that Au 60 S 6 (SCH 2 Ph) 36 consists of a fcc-like Au 20 kernel protected by a pair of giant Au 20 S 3 (SCH 2 Ph) 18 staple motifs, which contain 6 tetrahedral-coordinate μ 4 -S atoms not previously reported in the Au–S interface. Importantly, the fourth crystallographic closest-packed pattern, termed 6H left-handed helical (6HLH) arrangement, which results in the distinct loss of solid photoluminescence of amorphous Au 60 S 6 (SCH 2 Ph) 36 , is found in the crystals of Au 60 S 6 (SCH 2 Ph) 36 . The solvent-polarity-dependent solution photoluminescence is also demonstrated. Overall, this work provides important insights about the structure, Au–S bonding and solid photoluminescence of gold nanoclusters. Metal nanoclusters are explored for their precise structures and compelling properties. Here, the authors synthesize a gold cluster with unique structural features, including giant staple motifs, tetrahedral-coordinate μ 4 -S atoms, and a helical closest-packed crystallographic pattern that influences the cluster’s photoluminescence.

Ammonia is a promising carbon-free fuel. However, one of the main challenges for ammonia combustion is the high level of NO emissions. In this study, simulations were conducted for ammonia/air laminar counterflow flames and turbulent non-premixed jet flames in the KAUST high-pressure combustion duct (HPCD) at a pressure of 5 bar, with two ammonia cracking ratios of 14% and 28%. The influence of ammonia cracking ratio on the flame structure and NO formation mechanism were examined. The laminar counterflow flame results showed that HNO is one of the most critical species related to NO formation and NO is mainly generated through the path of NH2→NH→HNO→NO. For the turbulent flames, the flamelet/progress variable (FPV) approach was employed in the context of large eddy simulations (LES) for high-fidelity simulations. The simulation results were compared with the measured data with promising agreements, which proves the accuracy of the FPV method for the present flames. It was shown that with increasing cracking ratio, not only the flame reactivity is enhanced, but also the generation of NO is increased. The correlation between NO and HNO is weaker when compared to that between NO and radicals such as O, H and OH in the entire flame. Through the distribution of NO source terms, it was found that the NO source term has a higher absolute value in the upstream region and the absolute value rapidly decreases with increasing streamwise distance. The total NO source term is positive in the fuel-lean zone and shows negative values in the fuel-rich zone.

Data recovery from monolithic storage devices (MSDs) is in high demand for legal or business purposes. However, the conventional data recovery methods are destructive, complicated, and time-consuming. We develop a robotic-arm-assisted optical coherence tomography (robotic-OCT) for non-destructive inspection of MSDs, offering ~7 μm lateral resolution, ~4 μm axial resolution and an adjustable field-of-view to accommodate various MSD sizes. Using a continuous scanning strategy, robotic-OCT achieves automated volumetric imaging of a micro-SD card in ~37 seconds, significantly faster than the traditional stop-and-stare scanning that typically takes tens of minutes. We also demonstrate the robotic-OCT-guided laser ablation as a microsurgical tool for targeted area removal with precision of ±10 μm and accuracy of ~50 μm, eliminating the need to remove the entire insulating layer and operator intervention, thus greatly improving the data recovery efficiency. This work has diverse potential applications in digital forensics, failure analysis, materials testing, and quality control. Demand for data recovery from monolithic storage devices is high but current methods are inefficient. Here, authors develop a robotic OCT-guided inspection and microsurgery method, minimizing damage to device and enhancing data recovery efficiency.

Changes in physicochemical characteristics, chemical structures and maturity of swine, cattle and chicken manures and composts during 70-day composting without addition of bulking agents were investigated. Physicochemical characteristics were measured by routine analyses and chemical structures by solid-state 13C NMR and FT-IR. Three manures were of distinct properties. Their changes in physicochemical characteristics, chemical structures, and maturity were different not only from each other but also from those with addition of bulking agents during composting. Aromaticity in chicken manure composts decreased at first, and then increased whereas that in cattle and swine manure composts increased. Enhanced ammonia volatilization occurred without addition of bulking agents. NMR structural information indicated that cattle and chicken composts were relatively stable at day 36 and 56, respectively, but swine manure composts were not mature up to day 70. Finally, the days required for three manures to reach the threshold values of different maturity indices were different.

In order to solve the demand for low-power microcomputers and micro-electro-mechanical system components for continuous energy supply, a magnetic coupling piezoelectric–electromagnetic composite galloping energy harvester (MPEGEH) is proposed. It is composed of a piezoelectric energy harvester (PEH) and an electromagnetic energy harvester (EEH) coupled by magnetic force. The bistable nonlinear magnetic coupling structure improves the output power of the MPEGEH. The advantages and output performance of the MPEGEH are analyzed. The prototype of the energy harvester is made, and the nonlinear output characteristics under different load resistances are analyzed. Through the experiment on the key parameters of the composite energy harvester, it is found that the higher the coupling degree of the two parts of the MPEGEH, the stronger the nonlinear characteristics and the better the output characteristics. The results show that the onset wind velocity and output power of the MPEGEH are better than the classic galloping piezoelectric energy harvester (CGPEH). At the same wind speed, with the increase in the distance d0 between magnets A and B, the output power of both the PEH and the EEH decreases. When d0 is 37 mm, the output power of the EEH is the largest. The distance s0 between magnets B and C has little influence on the output power of the PEH but has a great influence on the EEH. When s0 is 23 mm, the EEH has the best output characteristics. Compared with the CGPEH, the onset wind velocity is reduced by 28%, and the output power is increased by 136% when the wind speed is 11 m/s.

Poultry and livestock are the most important reservoirs for pathogenic Escherichia coli and use of antimicrobials in animal farming is considered the most important factor promoting the emergence, selection and dissemination of antimicrobial-resistant microorganisms. The aim of our study was to investigate antimicrobial resistance in E. coli isolated from food animals in Jiangsu, China. The disc diffusion method was used to determine susceptibility to 18 antimicrobial agents in 862 clinical isolates collected from chickens, ducks, pigs, and cows between 2004 and 2012. Overall, 94% of the isolates showed resistance to at least one drug with 83% being resistance to at least three different classes of antimicrobials. The isolates from the different species were most commonly resistant to tetracycline, nalidixic acid, sulfamethoxazole, trimethoprim/sulfamethoxazole and ampicillin, and showed increasing resistance to amikacin, aztreonam, ceftazidime, cefotaxime, chloramphenicol, ciprofloxacin. They were least resistant to amoxicillin/clavulanic acid (3.4%) and ertapenem (0.2%). MDR was most common in isolates from ducks (44/44, 100%), followed by chickens (568/644, 88.2%), pigs (93/113, 82.3%) and cows (13/61, 21.3%). Our finding that clinical E. coli isolates from poultry and livestock are commonly resistant to multiple antibiotics should alert public health and veterinary authorities to limit and rationalize antimicrobial use in China.

Wolbachia are maternally transmitted intracellular bacteria that can naturally and artificially infect arthropods and nematodes. Recently, they were applied to control the spread of mosquito-borne pathogens by causing cytoplasmic incompatibility (CI) between germ cells of females and males. The ability of Wolbachia to induce CI is based on the prevalence and polymorphism of Wolbachia in natural populations of mosquitoes. In this study, we screened the natural infection level and diversity of Wolbachia in field-collected mosquitoes from 25 provinces of China based on partial sequence of Wolbachia surface protein ( wsp ) gene and multilocus sequence typing (MLST). Among the samples, 2489 mosquitoes were captured from 24 provinces between July and September, 2014 and the remaining 1025 mosquitoes were collected month-by-month in Yangzhou, Jiangsu province between September 2013 and August 2014. Our results showed that the presence of Wolbachia was observed in mosquitoes of Aedes albopictus (97.1%, 331/341), Armigeres subalbatus (95.8%, 481/502), Culex pipiens (87.0%, 1525/1752), Cx . tritaeniorhynchus (17.1%, 14/82), but not Anopheles sinensis (n = 88). Phylogenetic analysis indicated that high polymorphism of wsp and MLST loci was observed in Ae . albopictus mosquitoes, while no or low polymorphisms were in Ar . subalbatus and Cx . pipiens mosquitoes. A total of 12 unique mutations of deduced amino acid were identified in the wsp sequences obtained in this study, including four mutations in Wolbachia supergroup A and eight mutations in supergroup B. This study revealed the prevalence and polymorphism of Wolbachia in mosquitoes in large-scale regions of China and will provide some useful information when performing Wolbachia -based mosquito biocontrol strategies in China.

The Dalazi Formation in the Yanji Basin is primarily composed of fan delta and lacustrine facies, with local development of alluvial fan deposits. The second member of the Dalazi Formation (Da₂) serves as the key oil-bearing interval for exploration and development. Based on logging data, lithological observations, and maximum entropy spectral analysis (MESA), Da₂ is interpreted to mainly represent a continental fan delta system. Due to the complex depositional environment, significant variations exist in sedimentary types, resulting in notable differences in both lithology and logging curves, which hinders regional correlation using conventional logging marker bed pairings. In order to solve this problem, based on the theory of high resolution sequence stratigraphy and astronomical cycle theory, this paper uses the maximum entropy spectrum analysis, spectrum analysis and wavelet time–frequency analysis technology to process and analyze the natural gamma curve (GR) data, and combines the logging lithology information to identify the sequence interface. According to the prediction error trend (INPEFA) curve in MESA, it is identified that Da2 contains 1 long-term base level rise half-cycle and 1 long-term base level fall half-cycle. On this basis, the mid-term base level cycle and short-term base level cycle are identified by combining spectrum analysis technology and wavelet time–frequency technology. Finally, The Da2 sequence is subdivided into 1 long-term, 6 mid-term, and 16 short-term base level cycles, based on which a sequence stratigraphic division scheme is proposed. Based on this, a high-resolution stratigraphic framework is established, which provides accurate geological basis for subsequent comprehensive reservoir evaluation and sand body prediction.