•A sensory lexicon of fish noodle was established and 10 odor attributes were screened.•The flavor fingerprint of fish noodles was established using GC-IMS and GC-MS.•FS-fish noodle differed FR-fish ...noodle significantly in aroma profiles.•2-Methylpyrazine, heptanal, octanal and, nonanal contributed to “warmed-over” odor.
This study employs sensory evaluation, headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS), and headspace solid-phase microextraction gas chromatography–mass spectrometry (HS-SPME-GC-MS) techniques to investigate the effect of different pretreatment of fresh silver carp mince (running water rinsing 0, 1, or 2 times) and commercially frozen surimi on the odor characteristics of fish noodles. The free choice profiling (FCP) and check all that apply (CATA) sensory analysis methods were utilized to identify 10 characteristic descriptors, which include “grass, fish fragrance, unpleasant fishy, fatty, roast, ammonia, caramel, warmed-over, earthy, and mushroomy”. HS-GC-IMS and HS-SPME-GC-MS detected 80 and 37 volatile compounds (VCs) in fish noodles. The 1-Penten-3-ol, (E)-2-pentenal-D, hexanal-D, pentanal-D, (E,E)-2, 4-heptadienal-D contents were significantly correlated with “fish fragrance” and “unpleasant fishy”, and octanal, nonanal, heptanal, 2-methylpyrazine contents were significantly correlated with “warmed-over” flavor. The results of this study can be helpful for fish noodle quality improvement and industrial production.
The pantograph and its recess on the train roof are major aerodynamic noise sources on high-speed trains. Reducing this noise is particularly important because conventional noise barriers usually do ...not shield the pantograph. However, less attention has been paid to the pantograph recess compared with the pantograph. In this paper, the flow features and noise contribution of two types of noise reduction treatments rounded and chamfered edges are studied for a simplified high-speed train pantograph recess, which is represented as a rectangular cavity and numerically investigated at 1/10 scale. Improved delayed detached-eddy simulations are performed for the near-field turbulent flow simulation, and the Ffowcs Williams and Hawkings aeroacoustic analogy is used for far-field noise prediction. The highly unsteady flow over the cavity is significantly reduced by the cavity edge modifications, and consequently, the noise radiated from the cavity is reduced. Furthermore, effects of the rounded cavity edges on the flow and noise of the pantographs (one raised and one folded) are investigated by comparing the flow features and noise contributions from the cases with and without rounding of the cavity edges. Different train running directions are also considered. Flow analysis shows that the highly unsteady flow within the cavity is reduced by rounding the cavity edges and a slightly lower flow speed occurs around the upper parts of the raised pantograph, whereas the flow velocity in the cavity is slightly increased by the rounding. Higher pressure fluctuations occur on the folded pantograph and the lower parts of the raised pantograph, whereas weaker fluctuations are found on the panhead of the raised pantograph. This study shows that by rounding the cavity edges, a reduction in radiated noise at the side and the top receiver positions can be achieved. Noise reductions in the other directions can also be found.
Abstract Exploring an active and cost-effective electrocatalyst alternative to carbon-supported platinum nanoparticles for alkaline hydrogen evolution reaction (HER) have remained elusive to date. ...Here, we report a catalyst based on platinum single atoms (SAs) doped into the hetero-interfaced Ru/RuO 2 support (referred to as Pt-Ru/RuO 2 ), which features a low HER overpotential, an excellent stability and a distinctly enhanced cost-based activity compared to commercial Pt/C and Ru/C in 1 M KOH. Advanced physico-chemical characterizations disclose that the sluggish water dissociation is accelerated by RuO 2 while Pt SAs and the metallic Ru facilitate the subsequent H* combination. Theoretical calculations correlate with the experimental findings. Furthermore, Pt-Ru/RuO 2 only requires 1.90 V to reach 1 A cm −2 and delivers a high price activity in the anion exchange membrane water electrolyzer, outperforming the benchmark Pt/C. This research offers a feasible guidance for developing the noble metal-based catalysts with high performance and low cost toward practical H 2 production.
Abstract
The simple ABO
3
and A-site-ordered AA′
3
B
4
O
12
perovskites represent two types of classical perovskite functional materials. There are well-known simple perovskites with ferroelectric ...properties, while there is still no report of ferroelectricity due to symmetry breaking transition in A-site-ordered quadruple perovskites. Here we report the high pressure synthesis of an A-site-ordered perovskite PbHg
3
Ti
4
O
12
, the only known quadruple perovskite that transforms from high-temperature centrosymmetric paraelectric phase to low-temperature non-centrosymmetric ferroelectric phase. The coordination chemistry of Hg
2+
is changed from square planar as in typical A-site-ordered quadruple perovskite to a rare stereo type with 8 ligands in PbHg
3
Ti
4
O
12
. Thus PbHg
3
Ti
4
O
12
appears to be a combinatory link from simple ABO
3
perovskites to A-site-ordered AA′
3
Ti
4
O
12
perovskites, sharing both displacive ferroelectricity with former and structure coordination with latter. This is the only example so far showing ferroelectricity due to symmetry breaking phase transition in AA′
3
B
4
O
12
-type A-site-ordered perovskites, and opens a direction to search for ferroelectric materials.
Abstract
Electrochemical nitrate reduction to ammonia offers an attractive solution to environmental sustainability and clean energy production but suffers from the sluggish *NO hydrogenation with ...the spin–state transitions. Herein, we report that the manipulation of oxygen vacancies can contrive spin−polarized Fe
1
−Ti pairs on monolithic titanium electrode that exhibits an attractive NH
3
yield rate of 272,000 μg h
−1
mg
Fe
−1
and a high NH
3
Faradic efficiency of 95.2% at −0.4 V vs. RHE, far superior to the counterpart with spin−depressed Fe
1
−Ti pairs (51000 μg h
–1
mg
Fe
–1
) and the mostly reported electrocatalysts. The unpaired spin electrons of Fe and Ti atoms can effectively interact with the key intermediates, facilitating the *NO hydrogenation. Coupling a flow−through electrolyzer with a membrane-based NH
3
recovery unit, the simultaneous nitrate reduction and NH
3
recovery was realized. This work offers a pioneering strategy for manipulating spin polarization of electrocatalysts within pair sites for nitrate wastewater treatment.
Grape cluster detection is a crucial step in the visual tasks of automated grape harvesting. Background and occlusion lead to difficulty in detecting grape clusters under natural environments. Some ...improvements have been proposed to solve this issue. Firstly, the public dataset is enriched with the data augmentation methods of random brightness change, image flip left-right, and mosaic to strengthen the model's robustness. Secondly, based on the problem of information loss in grape cluster detection, a plug-and-play module of spatial-to-depth convolution (STD-Conv) is added to enrich grape cluster feature information. The original grape features are further fused by converting the spatial dimension of the input image into a depth dimension. Thirdly, a simple, parameter-free attention mechanism (SimAM) is applied to the backbone to improve the weight of grape targets and suppress background interference weight in feature extraction. Experiments show that combining STD-Conv and SimAM can improve the accuracy of YOLOv4, YOLOv5, and YOLOX. The improved YOLOX model achieves the highest 88.4% mean Average Precision (mAP), 87.8% precision, and 79.5% recall. These findings demonstrate that the enhanced YOLOX model performs well for grape cluster detection. This study's conclusion makes some valuable ideas for automated harvesting into grape or other fruit detection.
Improving the effectiveness of harvesting robots requires quick and accurate apple detection in natural environments. The colour and shape features of apples are corrupted due to the reflected light ...and the incomplete coverage of the fruit bag, bringing difficulties to apple detection. To address this issue, the Coordinate Attention You Only Look Once version 5 (CA-YOLOv5) is designed to simultaneously detect bagged and unbagged apples in the natural environment. Firstly, 1525 apple images are collected from apple orchards to build a dataset. Secondly, to solve the reflected light problem, all C3 modules in the Backbone are substituted for Coordinate Attention modules which can improve the feature representation of objects. Finally, to solve the incomplete bagging problem, the Path Aggregation Network in the Neck is replaced by a Bidirectional Feature Pyramid Network which can better fuse the features of various sizes. The CA-YOLOv5 network reaches 82.7%, 89.8%, 48.6%, and 87.0% for recall, mAP@0.5, mAP@0.5:0.95, and F1 score, respectively, which is 2.3%,1.2%,1.9%, and 2.9% higher than the YOLOv5. The results reveal that CA-YOLOv5 has much superior detection performance than the original YOLOv5, and it can serve as a technical benchmark for the development of automatic orchard-picking robots.
Significance The ground state of materials with strong electronic correlations depends on a delicate balance among competing interactions. The strongly correlated compounds Ce M In ₅, with M = Co, ...Rh, and Ir, exhibit superconducting and magnetic ground states as well as Fermi surface changes upon substituting one M element for another and become even higher temperature superconductors when Ce is substituted by Pu. They are therefore recognized as important model systems in which a search for parameters correlating with the occurrence of these ground states could be successful. The present X-ray absorption study of CeRh ₁₋ₓIr ₓIn ₅ reveals that anisotropy of the Ce 4 f -wave function is a significant parameter that is highly sensitive to the ground-state formation and should be taken into account when modeling these systems.
The interplay of structural, orbital, charge, and spin degrees of freedom is at the heart of many emergent phenomena, including superconductivity. Unraveling the underlying forces of such novel phases is a great challenge because it not only requires understanding each of these degrees of freedom, it also involves accounting for the interplay between them. Cerium-based heavy fermion compounds are an ideal playground for investigating these interdependencies, and we present evidence for a correlation between orbital anisotropy and the ground states in a representative family of materials. We have measured the 4 f crystal-electric field ground-state wave functions of the strongly correlated materials CeRh ₁₋ₓIr ₓIn ₅ with great accuracy using linear polarization-dependent soft X-ray absorption spectroscopy. These measurements show that these wave functions correlate with the ground-state properties of the substitution series, which covers long-range antiferromagnetic order, unconventional superconductivity, and coexistence of these two states.
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