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High-strength Al–Zn–Mg–Cu alloys such as AA7075 rely on precipitation to obtain their properties, and the evolution of these precipitates can be strongly influenced by deformation. In this study, the effect of warm stretching on precipitation in supersaturated AA7075 was investigated. A dilatometer was used to enable rapid quenching directly from the solution treatment temperature to the warm stretching temperature. The evolution of precipitates was monitored using small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). SAXS revealed the presence of clusters only 5 seconds after quenching, and the subsequent evolution of the microstructure involved the growth and coarsening of these clusters. Deformation strongly enhanced the cluster/precipitate growth rate, which increased linearly with increasing strain. A strain rate effect was also noted, with the growth rate being faster at the higher strain rate for the same strain level. However, the acceleration of growth with increasing strain rate was not sufficient to compensate for the reduced time, so that deformation at higher strain rate led to small precipitates (at iso-strain). TEM revealed the precipitates to be homogeneously dispersed in the matrix both with and without deformation. There was no evidence for enhanced nucleation due to deformation, indeed the opposite was the case, with fewer but larger precipitates observed in the deformed microstructure. The linear increase in growth rate with strain is consistent with a dominant effect of excess vacancies in enhancing diffusion rates.

Biogenic amines (BAs) represent a class of potentially harmful substances in foods and medicines. Their content is thus an important indicator of proper hygiene in food preparation, and purity of medicines. It is of great practical significance to establish accurate and sensitive detection of BAs in food and drugs. In this study, a high performance liquid chromatography (HPLC) method was developed for the simultaneous detection of multiple BAs in fish, pork and antibiotics based on aptamer signal replacement and cyclic amplification strategy. First, non-fluorescent targets were converted into fluorescent nucleic acid probes using a two-step replacement process. Subsequently, a large number of nucleic acid probes with different lengths and base sequences were generated using a double-stranded specific nuclease-assisted signal amplification strategy. Finally, various BAs in real samples were accurately identified using an HPLC platform. The influence of base sequence and nucleic acid probe length on separation via HPLC was studied to improve discrimination among fluorescent signals. Four different sequences were selected as tails to the DNA probe, and their retention times increased in turn. Experimental conditions, including column temperature, flow rate, gradient elution process, reaction temperature, and incubation time, were optimized by orthogonal experiments to further improve signal separation efficiency. Specifically, the methanol gradient was changed from 10% to 20% during 0-20 min, 35 ℃ of column temperature and 1.0 mL/min of flow rate were chosen as the HPLC conditions. The final resolution of chromatographic peaks was 3.44, 3.59 and 2.37, indicating complete separation between peaks. Optimal incubation time for BA capture by aptamer was 120 min, and optimal dosage of duplex specific nuclease (DSN) and Mg

This work presents a crystal plasticity model for dynamic precipitation in aluminium alloys. It takes into account both the influence of an evolving precipitate distribution on the critical stress for dislocation glide, and the accelerating effect of deformation on precipitation kinetics. The effect of precipitates on deformation behaviour is integrated into the crystal plasticity constitutive law. The effect of deformation on precipitation kinetics is modelled spatio-temporally using a multi-class precipitation kinetic model (KWN) incorporating the effect of deformation through accelerated solute diffusion caused by the production of excess vacancies. The model is applied to growth and coarsening of shearable precipitates in pre-aged AA7075 alloy under deformation at 150°C, which corresponds to an industrially relevant production. This paper first explores the influence of dynamic precipitation on the tensile behaviour, showing that dynamic precipitation might be responsible for a gain in uniform elongation and tensile stress of respectively 2% strain and 50 MPa for the case at hand. The influence of dynamic precipitation on the development of plastic strain heterogeneities is discussed. The model demonstrates how spatial heterogeneities in precipitate distribution may develop during deformation, and how these heterogeneities correlate with the development of strain heterogeneities. The precipitate distributions obtained under static or dynamic ageing are predicted and compared with each other, and the influence of texture is discussed.

High-numerical aperture ( N A > 0.6 ) Mueller matrix imaging polarimeter (MMIP) (high-NA MMIP) is urgently needed for higher resolution. Usually, the working distance of high-NA MMIP is too short to perform in situ calibration by a usual reference sample, such as polarizer and retarder plates. The polarization effects of the substrate that attach the sample are never calibrated. So, the resolution and accuracy of the MMIP is hard to further promote. In this paper, a holistic and efficient calibration method is innovated for high-NA MMIP. Two film polarizers and a film retarder as well as a blank substrate are first adopted as the reference samples in calibration. Different from the conventional eigenvalue calibration method (ECM), the holistic calibration theory and process are established. All polarimetric errors arising from the devices, subsystems, and the substrate can be calibrated in one process. The normalized measurement error is less than 0.0024 for NA 0.95 MMIP, which is an order of magnitude lower than those of NA 0.1 and 0.2 MMIPs in publications. The excellent performance of calibrated high-NA MMIP is demonstrated by tissue polarimetry with higher resolution, accuracy, and more appropriate dynamic range.

Efficient and low-cost electrocatalysts are urgently required for the electrocatalytic N

Spoken language understanding (SLU) is the core of the speech-centric human-robot interaction system, which mainly involves intent detection and slot filling. The recent SLU research focuses on the joint modeling of the two tasks due to their correlation. Furthermore, the slot information consists of slot position and slot type. Although the slot types are semantically related to the intent, the slot positions of the same intent may vary a lot in different utterances due to the diversity of spoken language. Thus, the conventional one-stage slot filling task may introduce unrelated information for slot position prediction in the slot-intent interaction of the joint modeling. Therefore, we propose a novel two-stage selective fusion framework for joint intent detection and slot filling. Unlike the previous one-stage framework, the proposed framework decomposes the slot filling into two stages, i.e., the slot proposal and slot classification. The slot proposal network consisting of BERT and bidirectional long short-term memory (Bi-LSTM)-conditional random field (CRF) predicts the slot positions. Instead of the tokenwise fusion in the existing methods, the slot-intent feature fusion is only performed in the slot classification. A selective fusion mechanism is designed to facilitate the slot-intent interaction within each slot candidate for more accurate slot-type classification. Experiments on five standard benchmarks (i.e., ATIS, SNIPS, MixATIS, MixSNIPS, and DSTC4) show that the proposed framework achieves the best performance in comparison with several state-of-the-art methods.

Mastitis is an emerging health concern in animals. An increased incidence of mastitis in dairy cows has been reported in the last few years across the world. It is estimated that up to 20% of cows are suffering from mastitis, causing incompetency in the mucosal immunity and resulting in excessive global economic losses in the dairy industry.

One of the key advantages of unmanned swarm operation is its autonomous cooperation. When the communication is interrupted or the centralized control manner is lost, the cooperative operation can still be carried out orderly. This work proposed a cooperative evolution mechanism within the framework of multiplayer public goods game to solve the problem of autonomous collaboration of unmanned swarm in case of failure of centralized control. It starts with the requirement analysis of autonomous cooperation in unmanned swarm, and then, the evolutionary game model of multiplayer public goods based on aspiration-driven dynamics is established. On this basis, the average abundance function is constructed by theoretical derivation, and furthermore, the influence of cost, multiplication factor, and aspiration level on the average abundance is simulated. Finally, the evolutionary mechanism of parameter adjustment in swarm cooperation is revealed via case study, and deliberate proposals are suggested to provide a meaningful exploration in the actual control of unmanned swarm cooperation.

Mueller matrix imaging polarimeters (MMIPs) have been developed in the wavelength region of >400nm with great potential in many fields yet leaving a void of instrumentation and application in the ultraviolet (UV) region. For the first time to our knowledge, an UV-MMIP is developed for high resolution, sensitivity, and accuracy at the wavelength of 265 nm. A modified polarization state analyzer is designed and applied to suppress stray light for nice polarization images, and the errors of the measured Mueller matrices are calibrated to lower than 0.007 in pixel level. The finer performance of the UV-MMIP is demonstrated by the measurements of unstained cervical intraepithelial neoplasia (CIN) specimens. The contrasts of depolarization images obtained by the UV-MMIP are dramatically improved over those obtained by our previous VIS-MMIP at the wavelength of 650 nm. A distinct evolution of depolarization in normal cervical epithelium tissue, CIN-I, CIN-II, and CIN-III specimens can be observed by the UV-MMIP with mean depolarization promotion by up to 20 times. This evolution could provide important evidence for CIN staging but can hardly be distinguished by the VIS-MMIP. The results prove that the UV-MMIP could be an effective tool in polarimetric applications with higher sensitivity.

Electroreduction of NO to NH3 under ambient conditions mitigates the human-caused imbalance in the global nitrogen cycle and represents a sustainable and on-site alternative to the industrial Haber–Bosch process, but its efficiency is challenged by the difficulty of identifying highly active and robust electrocatalysts for the NO reduction reaction (NORR). Herein, it is reported that a Ni2P nanosheet array on carbon paper (Ni2P/CP) acts as an efficient NORR electrocatalyst toward the highly selective hydrogenation of NO to NH3. In 0.1 M HCl, the Ni2P/CP displays a large NH3 yield of 33.47 μmol h−1 cm−2 and a fairly high faradaic efficiency of up to 76.9% at −0.2 V versus the reversible hydrogen electrode, with superb electrochemical durability under the working conditions. A proof-of-concept device consisting of a Zn–NO battery with Ni2P/CP as the cathode was assembled to deliver a discharge power density of 1.53 mW cm−2 and an NH3 yield of 62.05 μg h−1 mgcat.−1. Theoretical calculations reveal that the Ni2P (111) surface effectively promotes NO adsorption and activation via an “acceptance–donation” mechanism, and the potential-determining step is the hydrogenation of *NO to *NOH. Additionally, the possible formation of the H2 and other byproducts were also investigated theoretically, and the results support the high selectivity of the NO-to-NH3 conversion process.

Background: Rapidly developed broilers are often accompanied by excessive fat deposition and markedly decreased feed utilization, which is a severe problem in the poultry industry. Recent studies established that gut microbiota significantly alters chicken fat deposition. However, what kind of cecal bacteria can regulate fat deposition and how they control fat deposition remains unclear. Results: The abdominal fat weight and index, and average diameter of adipocytes were markedly higher in high than in low abdominal fat deposition chickens at different time points (1, 4, and 12 months). The higher expression levels of fat synthesis related genes (ACSL1, FADS1, CYP2C45, ACC, and FAS) and a lower expression of fat catabolism genes (CPT-1, and PPARα) in the liver and abdominal fat of high abdominal fat deposition chickens, indicated that an unbalanced fat metabolism leads to excessive abdominal fat deposition. Parabacteroides, Parasutterella, Oscillibacter, and Anaerofustis were found higher in high abdominal fat deposition chickens, while Bacteroides and Sphaerochaeta were higher in low abdominal fat deposition chickens at different time points. Further, Spearman correlation analysis indicated that the relative abundance of Parabacteroides, Parasutterella, Oscillibacter, and Anaerofustis was positively correlated with abdominal fat weight and index, and the expression level of fat anabolism genes, yet the relative abundance of Bacteroides and Sphaerochaeta was negatively correlated with these factors. Furthermore, transferring fecal microbiota from adult chickens with low abdominal fat deposition into one-day-old chicks significantly decreased Parabacteroides, abdominal fat weight and index, and fat anabolism genes, while markedly increased Bacteroides and Sphaerochaeta and fat catabolism genes. Conclusion: Our findings highlighted that Bacteroides and Sphaerochaeta might reduce abdominal fat deposition, yet Parabacteroides Parasutterella, Oscillibacter, and Anaerofustis could promote abdominal fat deposition by regulating fat metabolism.

Hollow carbon nanospheres with abundant mesoporous structure and enhanced N configuration active sites can reduce O2 to H2O2 with an ultrahigh H2O2 yield rate of 7.32 mol gcat.−1 h−1 and a high faradaic efficiency of 96.7% in 0.1 M KOH.

All gibbon species (Primates: Hylobatidae) are facing high extinction risk due to habitat loss and hunting. The Hainan gibbon Nomascus hainanus is the world’s most critically endangered primate, and one of the priority conservation actions identified is to establish artificial canopy corridors to reconnect fragmented forests. The effectiveness of artificial canopy bridge as a conservation tool for wild gibbons has not been widely tested, and the results are rarely published. We constructed the first canopy bridge for Hainan gibbon in 2015 to facilitate passage at a natural landslide; mountaineering-grade ropes were tied to sturdy trees with the help of professional tree climbers and a camera trap was installed to monitor wildlife usage. Hainan gibbon started using the rope bridge after 176 days, and usage frequency increased with time. All members in the gibbon group crossed the 15.8 m rope bridge except adult male. Climbing was the predominant locomotor mode followed by brachiation. This study highlights the use and value of rope bridges to connect forest gaps for wild gibbons living in fragmented forests. While restoring natural forest corridors should be a priority conservation intervention, artificial canopy bridges may be a useful short-term solution.

Eleven new polycyclic polyprenylated acylphloroglucinols (PPAPs, 1–11) and three new monocyclic polyprenylated acylphloroglucinols (MPAPs, 12–14), together with ten known analogues were isolated from the fruits of Garcinia multiflora. These PPAPs belong to three types including the bicyclic polyprenylated acylphloroglucinols (BPAPs), the caged PPAPs, and the complicated PPAPs. Their structures and absolute configurations were determined through HRESIMS, NMR spectroscopy data, electronic circular dichroism (ECD) calculations, and gauge-independent atomic orbital (GIAO) NMR calculations with DP4+ analyses. Moreover, compounds 2 and 7 exhibited moderate cytotoxicity against three human cancer lines (MCF-7, T98, and HepG2) with IC50 values ranging from 9.81 ± 1.56 to 17.00 ± 2.75 μM.

Aims: Phylogenetic endemism describes the extent to which unique phylogenetic lineages are constrained to restricted geographic areas. Previous studies indicate that species endemism is related to both past and modern climate, but studies of phylogenetic endemism are relatively rare and mainly focused on smaller regions. Here, we provide the first assessment of the patterns of species and phylogenetic endemism in angiosperm trees across the Northern Hemisphere as well as the relative importance of modern climate and glacial–interglacial climate change as drivers of these patterns. Location: Northern Hemisphere. Major taxa: Angiosperm trees. Methods: Using tree assemblages at the scale of 100 km × 100 km grid cells and simultaneous autoregressive (SAR) models, we assessed the relationships between species endemism, phylogenetic endemism and modern climate variables, Last Glacial Maximum (LGM) to present temperature velocity. Results: Species and phylogenetic endemism were associated with both modern climate and glacial–interglacial climate change, with higher values in areas with stable historical climate and warmer and wetter modern conditions. Notably, the multivariate SAR analyses showed that the combinations of variables with highest Akaike’s information criterion (AIC) weight always included both LGM–present climate instability and modern climate, that is, modern precipitation and temperature. Main conclusions: Our results show that high phylogenetic endemism is partially dependent on long-term climate stability, highlighting the threat posed by future climate changes to the preservation of rare, phylogenetically distinct lineages of trees.