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Conics on Barth-Bauer octics

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Science China mathematics 2024年第7期67卷 1507-1524页

作者： alex Degtyarev Department of mathematics Bilkent UniversityAnkara06800Turkey

We analyze the configurations of conics and lines on a special class of Kummer octic surfaces. In particular, we bound the number of conics by 176 and show that there is a unique surface with 176 conics, all irreducible: it admits a faithful action of one of the mukai groups. Therefore, we also discuss conics and lines on mukai surfaces: we discover a double plane(ramified at a smooth sextic curve) that contains 8,910 smooth conics.

关键词： K3-surface octic surface Kummer surface conic mukai group

Developing the new soil science——Advice for early-career soil scientists

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Pedosphere 2024年第1期34卷 3-4页

作者： alex mcBRATNEY Sydney Institute of Agriculture&School of Life and Environmental Sciences The University of SydneySydney NSW 2006Australia

Confucius said,“To know what you know and what you do not know, that is true knowledge.”Hartemink (2006) edited a prescient book on the future of soil science, the contents of which are worthy of consideration today. Since then, there has been a growing emphasis on soil carbon, soil health, and soil security, as well as increased capability of technology related to machine leaning and soil sensing and *** KNOWLEDGE DISCOvERY CATEGORISATION Based on the above ancient aphorism attributed to Confucius, the author writing in Hartemink (2006) classified soil knowledge and knowledge discovery into 4 categories. An updated version is given in Fig. 1.

关键词： soil measurement. leaning

Blast waveform tailoring using controlled venting in blast simulators and shock tubes

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Defence Technology（防务技术） 2024年第7期37卷 14-26页

作者： Edward Chern Jinn Gan alex Remennikov David Ritzel Faculty of Engineering and Information Sciences University of WollongongWollongongNSW2522Australia Dyn-FX Consulting Ltd 19 Laird Ave NorthAmherstburgONN9V 2T5Canada

A critical challenge of any blast simulation facility is in producing the widest possible pressure-impulse range for matching against equivalent high-explosive *** tubes and blast simulators are often constrained with the lack of effective ways to control blast wave profiles and as a result have a limited performance *** wave shaping techniques employed in some facilities are reviewed but often necessitate extensive geometric modifications,inadvertently cause flow anomalies,and/or are only applicable under very specific *** paper investigates controlled venting as an expedient way for waveforms to be tuned without requiring extensive modifications to the driver or existing geometry and could be widely applied by existing and future blast simulation and shock tube *** use of controlled venting is demonstrated experimentally using the Advanced Blast Simulator(shock tube)at the Australian National Facility of Physical Blast Simulation and via numerical flow simulations with Computational Fluid *** venting is determined as an effective method for mitigating the impact of re-reflected waves within the blast *** control method also allows for the adjustment of parameters such as tuning the peak overpressure,the positive phase duration,and modifying the magnitude of the negative phase and the secondary shock of the blast *** paper is concluded with an illustration of the potential expanded performance range of the Australian blast simulation facility when controlled venting for blast waveform tailoring as presented in this paper is applied.

关键词： Advanced blast simulator Shock wave propagation Far-field explosion Blast loads Blast waves Computational fluid dynamics

No evidence of predator odor avoidance in a North American bird community

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Avian Research 2024年第1期15卷 133-138页

作者： Austin Dotta Batur Yaman alex van Huynh Department of Biology DeSales University2755 Station AvenueCenter ValleyPAUSA

Recent advances in our understanding of avian chemical communication have highlighted the importance of olfaction in many aspects of avian *** studies investigating predator avoidance behaviors in response to predator odor cues have produced mixed results across species and *** we assess if a community of birds in eastern Pennsylvania displays avoidance behaviors towards predator odor cues in a natural foraging *** use clay caterpillars to measure foraging activity by birds in the presence of predator(bobcat)urine,non-predator(rabbit)urine,and water controls in two different environmental contexts(field ***).Although we detected a weak trend for birds to forage less at predator urine-treated sites,we found no significant difference in avian foraging between the site *** did find that foraging rates between environmental contexts changed significantly over the course of the experiment,with forest sites showing decreasing foraging rates and field sites showing increasing foraging *** results reinforce the published literature that avoidance of predator odors by birds may not be ubiquitous across contexts and species.

关键词： Foraging Odor Olfaction Predation Predator-avoidance

Embedded majorana islands

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Science China(Physics,mechanics & Astronomy) 2024年第9期Mechanics & Astronomy) .卷 158-168页

作者： Jin-Xing Hou alex Weststr?m Rui Wang Wen-Li Yang Jian Li Institute of modern Physics Northwest University Department of Physics School of ScienceWestlake University Shaanxi Key Laboratory for Theoretical Physics Frontiers Institute of Natural Sciences Westlake Institute for Advanced Study National Laboratory of Solid State microstructures and Department of Physics Nanjing University Collaborative Innovation Center for Advanced microstructures Peng Huanwu Center for Fundamental Theory

mesoscopic superconducting islands hosting majorana zero modes(mZms), or majorana islands in short, offer a prototype of topological qubits. In this work we investigate theoretically the model of a generic majorana island tunneling-coupled to a singlepiece metallic substrate, hence an embedded majorana island. We show the crucial consequences of an interplay between the topological ground states nonlocally addressed by the mZms and the metallic bath with coherent electron propagation: on the one hand, the topological degeneracy on the majorana island can be preserved, by virtue of the particle-hole symmetry, despite the apparent bath-induced coupling between mZms; on the other hand, the electronic interference in the metallic bath may lead to profound alterations to the renormalization group behavior of the hybrid system towards low energy/temperature compared with conventional Kondo physics. This work serves to establish the model of embedded majorana islands as an experimentally relevant and theoretically intriguing problem particularly in the direction of topological quantum computation.

关键词： majorana zero modes mesoscopic superconductor topological Kondo effect topological quantum computation topological qubit

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Reinforcement Learning-Empowered Graph Convolutional Network Framework for Data Integrity Attack Detection in Cyber-Physical Systems

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CSEE Journal of Power and Energy Systems 2024年第2期10卷 797-806页

作者： Edeh vincent mehdi Korki mehdi Seyedmahmoudian alex Stojcevski Saad mekhilef School of Science Computingand Engineering TechnologiesSwinburne University of TechnologyMelbourneAustralia

The massive integration of communication and information technology with the large-scale power grid has enhanced the efficiency, safety, and economical operation of cyber-physical systems. However, the open and diversified communication environment of the smart grid is exposed to cyber-attacks. Data integrity attacks that can bypass conventional security techniques have been considered critical threats to the operation of the grid. Current detection techniques cannot learn the dynamic and heterogeneous characteristics of the smart grid and are unable to deal with non-euclidean data types. To address the issue, we propose a novel Deep-Q-Network scheme empowered with a graph convolutional network (GCN) framework to detect data integrity attacks in cyber-physical systems. The simulation results show that the proposed framework is scalable and achieves higher detection accuracy, unlike other benchmark techniques.

关键词： Deep reinforcement learning graph convolutional network heterogeneous smart grid network

Dietary supplementation of zinc oxide modulates intestinal functionality during the post-weaning period in clinically healthy piglets

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Journal of Animal Science and Biotechnology 2024年第1期15卷 313-328页

作者： Dirkjan Schokker Soumya K.Kar Els Willems alex Bossers Ruud A.Dekker Alfons J.m.Jansman Wageningen Bioveterinary Research LelystadThe Netherlands Wageningen Livestock Research Wageningen University&ResearchWageningenThe Netherlands Royal Agrifirm Group ApeldoornThe Netherlands Institute for Risk Assessment Sciences Utrecht UniversityUtrechtThe Netherlands

Background To improve our understanding of host and intestinal microbiome interaction,this research investigated the effects of a high-level zinc oxide in the diet as model intervention on the intestinal microbiome and small intestinal functionality in clinically healthy post-weaning *** study 1,piglets received either a high concentration of zinc(Zn)as zinc oxide(Zn O,Zn,2,690 mg/kg)or a low Zn concentration(100 mg/kg)in the diet during the post weaning period(d 14–23).The effects on the piglet's small intestinal microbiome and functionality of intestinal tissue were *** study 2,the impact of timing of the dietary zinc intervention was investigated,i.e.,between d 0–14 and/or d 14–23 post weaning,and the consecutive effects on the piglet's intestinal functionality,here referring to microbiota composition and diversity and gene expression *** Differences in the small intestinal functionality were observed during the post weaning period between piglets receiving a diet with a low or high concentration Zn O content.A shift in the microbiota composition in the small intestine was observed that could be characterized as a non-pathological change,where mainly the commensals *** the immediate post weaning period,i.e.,d 0–14,the highest number of differentially expressed genes(DEGs)in intestinal tissue were observed between animals receiving a diet with a low or high concentration Zn O content,i.e.,23 DEGs in jejunal tissue and 11 DEGs in ileal *** genes are involved in biological processes related to immunity and inflammatory *** example,genes CD59 and REG3G were downregulated in the animals receiving a diet with a high concentration Zn O content compared to low Zn O content in both jejunum and ileum *** the second study,a similar result was obtained regarding the expression of genes in intestinal tissue related to immune pathways when comparing piglets receiving a diet with a high concentration Zn O con

关键词： Immune system Intestinal functionality microbiota Piglets Zinc oxide

A pressure-sensitive rheological origin of high friction angles of granular matter observed in NASA–mGm project

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Chinese Physics B 2024年第6期33卷 559-567页

作者：程晓辉肖世泽杨森赵乃峰 alex Sixie Cao Department of Civil Engineering Tsinghua UniversityBeijing 100084China College of Transportation Engineering Nanjing Tech UniversityNanjing 211816China Institute of Structural Engineering ETH ZurichZurich 8092Switzerland

An abnormally high peak friction angle of Ottawa sand was observed in(National Aeronautics and Space Administration) NASA–(mechanics of Granular materials) mGm tests in microgravity conditions on the space shuttle. Previous investigations have been unsuccessful in providing a constitutive insight into this behavior of granular materials under extremely low effective stress conditions. Here, a recently proposed unified constitutive model for transient rheological behavior of sand and other granular materials is adopted for the analytical assessment of high peak friction angles. For the first time, this long-eluded behavior of sand is attributed to a hidden rheological transition mechanism, that is not only rate-sensitive, but also pressure-sensitive. The NASA–mGm microgravity conditions show that shear-tests of sand can be performed under abnormally low confining stress conditions. The pressure-sensitive behavior of granular shearing that is previously ignored is studied based on the μ(I) rheology and its variations. Comparisons between the model and the NASA microgravity tests demonstrate a high degree of agreement. The research is highly valid for pressure-sensitive and rate-dependent problems that occur during earthquakes, landslides, and space exploration.

关键词： granular matter microgravity pressure-sensitive NASA–mGm

The Potential Game-Changer:A Concept-to-Proof Study on D:A Heterojunction-Free Organic Photovoltaics

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Chinese Journal of Chemistry 2024年第3期42卷 252-258页

作者： Lijian Zuo Sae Byeok Jo Xueliang Shi Francis Lin alex Jen State Key Laboratory of Silicon and Advanced Semiconductor materials MOE Key Laboratory of Macromolecular Synthesis and FunctionalizationDepartment of Polymer Science and EngineeringZhejiang UniversityHangzhouZhejiang310058 China Department of materials Science and Engineering University of WashingtonSeattleWAUSA School of Chemical Engineering Sungkyunkwan University (SKKU)Suwon16419 Republic of Korea School of Chemistry and molecular Engineering East China Normal UniversityShanghai200062 China Department of materials Science and Engineering City University of Hong KongKowloonHong KongChina Department of Chemistry City University of Hong KongKowloonHong KongChina Hong Kong Institute for Clean Energy Hong KongChina

Since 1986,the donor-acceptor (D:A) heterojunction has been regarded a necessity for high-efficiency organic photovoltaics (OPvs),due to its unique advantage in compensating the intrinsic limitations of organic semiconductors,such as high exciton binding energy and poor ambipolar charge mobility. While this adversely causes tremendous non-radiative charge recombination and instability issues,which currently become the most critical limits for commercialization of OPvs. Here,we present a concept-to-proof study on the potential of D:A heterojunction free OPv by taking advantage of recent progress of non-fullerene acceptors. First,we demonstrate that the “free carriers” can be spontaneously generated upon illumination in an NFA,i.e.,the 6TIC-4F single layer. Second,the 6TIC-4F layer also exhibits good ambipolar charge transporting property. These exceptional characteristics distinguish it from the traditional organic semiconductors,and relieve it from the reliance of D:A heterojunction to independently work as active layer. As a result,the subsequent OPv by simply sandwiching the 6TIC-4F layer between the cathode and anode yields a considerably high power conversion efficiency ~1%. moreover,we find the D:A heterojunction free device exhibits two order of magnitude higher electroluminescence quantum efficiency and significantly reduced vOC loss by 0.16 ev compared to those of the D:A BHJ structure,validating its promise for higher efficiency in the future. Therefore,our work demonstrates the possibility of using D:A heterojunction-free device structure for high performance,that can potentially become the next game changer of OPv.

关键词： Organic solar cells Spontaneous charge generation Ambipolar charge transport Charge recombination Perovskite-like organic semiconductor Schottky-junction structure Single component