We investigate the weak and strong deflection gravitational lensing by a quantum deformed Schwarzschild black hole and find their observables. These lensing observables are evaluated and the ...detectability of the quantum deformation is assessed, after assuming the supermassive black holes Sgr A* and M87* respectively in the Galactic Center and at the center of M87 as the lenses. We also intensively compare these findings with those of a renormalization group improved Schwarzschild black hole and an asymptotically safe black hole. We find that, among these black holes, it is most likely to test the quantum deformed Schwarzschild black hole via its weak deflection lensing observables in the foreseen future.
Weak and strong deflection gravitational lensing by a renormalization group improved Schwarzschild black hole is investigated and its observables are found. By taking the supermassive black holes Sgr ...A* and M87* respectively in the Galactic Center and at the center of M87 as lenses, we estimate these observables and analyse possibility of detecting this quantum improvement. It is not feasible to distinguish such a black hole by most observables in the near future except for the apparent size of the shadow. We also note that directly using measured shadow of M87* to constrain this quantum effect requires great care.
Time delay of the photons coupled to the Weyl tensor in a regular phantom black hole is investigated in both weak and strong deflection gravitational lensing. We find that the time delay in the weak ...deflection lensing strongly depends on the phantom hair while the delay in the strong deflection lensing is significantly affected by the hair and the strength of the coupling. We suggest that it is necessary to measure these two kind of time signals for fully understanding and distinguishing such an interaction beyond the standard Einstein–Maxwell theory.
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•A novel TiO2/g-C3N4-PS system was proposed for micropollutant degradation.•The TiO2/g-C3N4-PS system exhibits a high efficiency, nonselectivity and great stability.•The effects of ...different reaction conditions on the degradation rate of AAP were systematically studied.•The addition of PS greatly improved the degradation efficiency and oxidizing performance of the TiO2/g-C3N4 system.•The photocatalytic mechanism in the TiO2/g-C3N4-PS system was proposed.
A novel TiO2/g-C3N4-PS system was proposed, in which a TiO2/g-C3N4 heterojunction was used to activate persulfate (PS) to enhance pollutant photodegradation under visible-light irradiation. In this study, the TiO2/g-C3N4 photocatalyst was synthesized by a simple calcination method, and acetaminophen (AAP) was chosen as a model pollutant to test the degradation efficiency of the photocatalytic system. The TiO2/g-C3N4-PS system exhibits an efficient activity for PS activation and a high efficiency for pollutant degradation. The results show that 100 mL of a 5 mg/L AAP solution could be almost completely degraded in 30 min with 0.5 g/L photocatalyst and 2 mM PS, and TOC can be decreased by 82.5% in 60 min. After adding PS, the degradation rate of the TiO2/g-C3N4 photocatalytic system was greatly improved by nearly 13 times, compared to the TiO2/g-C3N4 system. The radical quenching experiments and electron paramagnetic resonance (EPR) results indicate that SO4−, OH and h+ all contribute to eliminating organic compounds. Additionally, the TiO2/g-C3N4-PS photocatalytic system was employed to eliminate other typical micropollutants, such as phenol, bisphenol A and carbamazepine, and experiments were also carried out using real water matrices, and the ideal performance shows that the TiO2/g-C3N4-PS photocatalytic system has a strong nonselective oxidative ability for degrading contaminants.
Abstract Determining the mass of neutron stars is crucial for understanding their formation, evolution, and interior structure. Currently, only a few dozen neutron stars have had their masses ...measured, and most of them belong to binary systems. However, there are a huge number of isolated neutron stars with unknown masses. Microlensing events with neutron stars provide unique opportunities for knowing these compact objects. Astrometric microlensing with a background source lensed by a neutron star might be used to determine the neutron star's mass by measuring the deviation of the motion of the centroid of the images from its unlensed one. We search and predict these recent and future events based on the Australia Telescope National Facility Pulsar Catalog and Gaia DR3. We find 60 candidate astrometric microlensing events caused by neutron stars and the probability distributions of their observables by the Monte Carlo sampling. We also find four candidate “timing microlensing” events with a pulsar lensed by a foreground object that might be detected by timing measurements. While some of these events may be verified by future astrometric missions or pulsar-timing observations, we note that our prediction of these events is significantly restricted by the uncertainties of the available astrometric and timing measurements after assessing and comparing our results with previous works.
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•Non-proportional loading paths imposed on nickel-based superalloy using crystal plasticity.•Potential mechanistic explanation for non-proportional detrimental effects in fatigue ...proposed.•Non-proportionality giving more slip activations, driving up GND and leading to shorter lives.
A dislocation and gradient-based crystal plasticity finite element study of fatigue has been carried out for nickel-based superalloy RR1000 in order to investigate detrimental non-proportional effects on fatigue life. Six differing multiaxial loading cycles including both proportional and non-proportional paths have been addressed and a critical stored energy density criterion employed for fatigue life. Non-proportional paths are shown to lead to higher numbers of intragranular slip system activations, reflecting experimental observations. These give higher geometrically necessary dislocation (GND) densities resulting from slip system interaction occurring through latent hardening effects in the model. The higher GND densities in turn drive up local stress and stored energy densities, thereby leading to lower predicted fatigue lives, in keeping with non-proportional fatigue experiments in the alloy considered. Intragranular slip system interaction may be the mechanistic explanation for non-proportional effects in fatigue of engineering alloys.
A single device combining the functions of a CO2 electrolyzer and a formate fuel cell is a new option for carbon‐neutral energy storage but entails rapid, reversible and stable interconversion ...between CO2 and formate over a single catalyst electrode. We report a new catalyst with such functionalities based on a Pb–Pd alloy system that reversibly restructures its phase, composition, and morphology and thus alters its catalytic properties under controlled electrochemical conditions. Under cathodic conditions, the catalyst is relatively Pb‐rich and is active for CO2‐to‐formate conversion over a wide potential range; under anodic conditions, it becomes relatively Pd‐rich and gains stable catalytic activity for formate‐to‐CO2 conversion. The bifunctional activity and superior durability of our Pb–Pd catalyst leads to the first proof‐of‐concept demonstration of an electrochemical cell that can switch between the CO2 electrolyzer/formate fuel cell modes and can stably operate for 12 days.
A lead–palladium alloy catalyst that reversibly changes its composition and function under electrochemically reducing versus oxidizing conditions is reported. Its bifunctional activity and superior durability enable a proof‐of‐concept electrochemical device integrating the functions of a carbon dioxide electrolyzer and a formate fuel cell.
Menthae Haplocalycis herba, one kind of Chinese edible herbs, has been widely utilized for the clinical use in China for thousands of years. Over the last decades, studies on chemical constituents of ...Menthae Haplocalycis herba have been widely performed. However, less attention has been paid to non-volatile components which are also responsible for its medical efficacy than the volatile constituents. Therefore, a rapid and sensitive method was developed for the comprehensive identification of the non-volatile constituents in Menthae Haplocalycis herba using ultra-high performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometry (UHPLC-LTQ-Orbitrap). Separation was performed with Acquity UPLC
BEH C
column (2.1 mm × 100 mm, 1.7 μm) with 0.2% formic acid aqueous solution and acetonitrile as the mobile phase under gradient conditions. Based on the accurate mass measurement (<5 ppm), MS/MS fragmentation patterns and different chromatographic behaviors, a total of 64 compounds were unambiguously or tentatively characterized, including 30 flavonoids, 20 phenolic acids, 12 terpenoids and two phenylpropanoids. Finally, target isolation of three compounds named Acacetin, Rosmarinic acid and Clemastanin A (first isolated from Menthae Haplocalycis herba) were performed based on the obtained results, which further confirmed the deduction of fragmentation patterns and identified the compounds profile in Menthae Haplocalycis herba. Our research firstly systematically elucidated the non-volatile components of Menthae Haplocalycis herba, which laid the foundation for further pharmacological and metabolic studies. Meanwhile, our established method was useful and efficient to screen and identify targeted constituents from traditional Chinese medicine extracts.
In this paper, a Gaussian mixture network distribution finance has been carried out to assess the risk, which is used as a risk assessment tool for the visual platform of higher vocational financial ...education. Financial data is quantified and determined by determining the cumulative expected loss amount to establish the financial investment risk assessment function. The Activiti open-source workflow engine was utilized to remove complex financial data and configure the K-line as the platform’s data visualization tool. Finally, the financial education visualization platform was used to analyze the Gaussian distribution and K-line data of X stock, which verified the practicality of the platform, and the effectiveness of the platform was verified by taking the students of H higher vocational college as the sample of the teaching experiment. The results show that the influence coefficient of the platform teaching on the quality of the course is 0.856, and the influence coefficient on the learning interest is 0.887, which indicates that the visual platform teaching makes students interested and strengthens their cognitive level. The visual digital reform of teaching finance majors in colleges and universities is provided with a new reference direction by this paper.
Hashing could significantly accelerate large-scale image search by transforming the high-dimensional features into binary Hamming space, where efficient similarity search can be achieved with very ...fast Hamming distance computation and extremely low storage cost. As an important branch of hashing methods, multi-view hashing takes advantages of multiple features from different views for binary hash learning. However, existing multi-view hashing methods are either based on shallow models which fail to fully capture the intrinsic correlations of heterogeneous views, or unsupervised deep models which suffer from insufficient semantics and cannot effectively exploit the complementarity of view features. In this paper, we propose a novel Deep Collaborative Multi-view Hashing (DCMVH) method to deeply fuse multi-view features and learn multi-view hash codes collaboratively under a deep architecture. DCMVH is a new deep multi-view hash learning framework. It mainly consists of 1) multiple view-specific networks to extract hidden representations of different views, and 2) a fusion network to learn multi-view fused hash code. DCMVH associates different layers with instance-wise and pair-wise semantic labels respectively. In this way, the discriminative capability of representation layers can be progressively enhanced and meanwhile the complementarity of different view features can be exploited effectively. Finally, we develop a fast discrete hash optimization method based on augmented Lagrangian multiplier to efficiently solve the binary hash codes. Experiments on public multi-view image search datasets demonstrate our approach achieves substantial performance improvement over state-of-the-art methods.
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