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Forming conditions of blisters during solution heat treatment of Al–Si alloy semi-solid die castings

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Rare Metals 2023年第11期42卷 3851-3858页

作者： Hong-Xing Lu Qiang Zhu stephen P.Midson Wen-Ying Qu Fan Zhang Da-Quan Li National Engineering and Technology Research Center for Nonferrous Metal Matrix Composites General Research Institute for Nonferrous MetalsBeijing100088China Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhen518055China

In the present study,numerical simulation method was used to analyze the conditions,resulting in the formation of blisters during solution heat *** formation is considered to occur as the height of blister reaches 5μ*** effects of process parameters on the magnitude of the forming temperatures of blister(Tb)were *** kinds of Al-Si alloys were used to analyze the effect of mechanical properties of the alloys on blister forming *** results show that decreasing the initial pressure in gas hole,the long-short axial ratio of gas hole and the size of gas hole,as well as increasing the depth of gas hole and the strength of alloy are helpful to increase the critical temperature of forming *** conclusions are helpful for casters to understand the conditions controlling blister formation during solution heat treatment and take actions to avoid the blister defects.

关键词： Blister Forming condition Semi-solid die casting Aluminum alloy

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Palaeogeographic variation in the Permian-Triassic boundary microbialites:A discussion of microbial and ocean process esafter the end-Permian mass extinction

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Journal of Palaeogeography 2017年第2期6卷 97-107页

作者： stephen Kershaw Department of Life Sciences Brunel University Kingston Lane Uxbridge UB8 3PH UK

Shallow marine carbonate sediments that formed after the end-Permian mass extinction are rich in a thin(maximum ca.15 m) deposit of *** communities that constructed the microbialites have geographic variability of composition,broadly divisible into two groups:1) eastern Tethys sites are calcimicrobe-dominated(appearing as thrombolites in the field),with rare occurrence of sedimentconstructed microbialites and uncommon cements either within microbial structure or as inorganic precipitates,2) other Tethys sites are sediment-dominated structures forming stromatolites and thrombolites,composed of micrites and cements,with some inorganic *** other Tethys locations include western and central Tethys sites but their palaeogeographic positions depend on the accuracy of continental reconstructions,of which there are several *** contrast to geographic variation of microbialites,the conodont Hindeodus parvus,which appeared after the extinction and defines the base of the Triassic,is widespread,indicating easy lateral migration throughout *** animals were active nekton,although being small animals were presumably at least partly carried by water currents,implying active Tethyan surface water circulation after the extinction ***-extinction ammonoid taxa,presumed active swimmers,show poor evidence of a wide distribution in the Griesbachian beds immediately after the extinction,but are more cosmopolitan higher up,in the Dienerian strata in *** shelly fossils also have poorly defined distributions after the extinction,but ostracods show some wider distribution suggesting migration was possible after the *** there is a contrast between the geographic differences of microbialites and some shelly *** the cause of geographic variation of post-extinction microbialites is problematic and may include one or more of the following possibilities:1) because calcifying microbial organisms th

关键词： Stromatolite Thrombolite Microbialite Permian-Triassic boundary Conodonts Tethys Mass extinction

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Robotic surgery for multi-visceral resection in locally advanced colorectal cancer:Techniques,benefits and future directions

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Laparoscopic, Endoscopic and Robotic Surgery 2023年第4期6卷 123-126页

作者： Chahaya Gauci Praveen Ravindran stephen Pillinger Andrew Craig Lynch Australian Robotic Colorectal Surgery SydneyAustralia Sydney Medical School Unversity of Sydney.Sydney Australia St George and Sutherland Clinical School Uhriversity of New South Wules MedidneSydneyAustrulia College of Health and Medicine Australian National UnversityCanberraAustulia

Colorectal cancer accounts for 10%of diagnosed cancers globally and often presents as advanced disease,necessitating aggressive *** both younger and healthier elderly patients being diagnosed,as well as potentially the need for salvage therapy post total neoadjuvant treatment,surgical options for cure include pelvic *** typically performed via an open approach,there has been an increased utilisation of minimally invasive techniques including robotic *** smaller in-cisions,reduced postoperative pain,and quicker recovery time than open surgery,robotic techniques have demonstrated lower blood loss,shorter hospital stays,and reduced ***,the er-gonomic design of robotic systems provides surgeons with comfort during long procedures and increased *** also offers an increased opportunity for organ preservation and reconstruction whilst maintaining adequate oncological *** robotic technology continues to evolve and combines with artificial intelligence,it is poised to play an even more significant role in the management of complex colorectal cancer cases,improving survival and long-term outcomes.

关键词： Colorectal neoplasms Robotic surgical procedures Pelvic exenteration Multivisceral surgery Artificial intelligence

Mapping groundwater dependent ecosystem potential in a semi-arid environment using aremote sensing-based multiple-lines-of-evidence approach

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International Journal of Digital Earth 2023年第1期16卷 375-406页

作者： stephen G.Fildes Tanya M.Doody David Bruce Ian F.Clark Okke Batelaan UniSA STEM University of South AustraliaAdelaideAustralia CSIRO Land and WaterAdelaideAustralia National Centre for Groundwater Research and Training(NCGRT) College of Science and EngineeringFlinders UniversityBedford ParkAustralia

Groundwater dependent ecosystems(GDEs)are vulnerable to groundwater regime ***,their protection is often hampered by challenges in their *** is presented a remote sensing-based GDE potential mapping approach based on the persistency of relevant vegetation parameters during prolonged dry periods as an indicator of potential‘consistency’of water supply(***).The study uses a novel approach to characterising persistency for selected vegetation parameters based on a normalised difference measure and an adaptation of the coefficient of variation *** of parameters was facilitated through the analytic hierarchy process providing a structured weighting approach to minimise parameter *** approach is demonstrated in the semi-arid Flinders Ranges of South Australia where new groundwater resources are being sought to support local domestic and industry *** in GDE potential were mapped to better target areas where exploration of groundwater should be *** results indicated a high-level of agreement of 77%with an independent springs dataset,along with an 87%agreement with areas coinciding with known phreatophyte species and depths to *** index-based mapping approach has potential applicability across landscapes,as it normalises for variations in vegetation cover,minimises technical overheads,and employs continental-wide remote sensing data-products.

关键词： coefficient of variation NDVI coefficient of variation fractional cover barest Earth wetness percentiles actual evapotranspiration analytic hierarchy process groundwater potential

Calcium-mediated paired pulse depression in juvenile rat dorsal striatum

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Neural Regeneration Research 2012年第10期7卷 772-777页

作者： Yufeng Xie Michael F. Jackson John F. macdonald Robarts Research Institute University of Western Ontario London Ontario Canada Department of Physiology and Pharmacology University of Western Ontario London Ontario Canada Department of Anatomy and Cell Biology University of Westem Ontario London Ontario Canada

As the major division of the basal ganglia, neostriatum forms mutual connections with multiple brain areas and is critically involved in motor control and learning/memory. Long-term synaptic plasticity has been widely studied in different species recently. However, there are rare reports about the short-term synaptic plasticity in neostratium. In the present study, using field excitatory postsynaptic potentials recording, we reported one form of short-term synaptic plasticity that is paired pulse depression in juvenile rat dorsal striatum slices induced by stimuli of the white matter. The field excitatory postsynaptic potentials could be abolished by α-amino-3-hydroxy-5-methylizoxazole-4-propionic acid receptor antagonist, 6-cyano-7-nitroquinoxaline-2,3-dione, but not by gamma-aminobutyric acid type A receptor antagonist bicuculline or dopamine D1 receptor antagonist SKF-81297. The paired pulse depression in the corticostratial pathway was different from paired pulse facilitation in the hippocampal CA1 synapse. In addition, the paired pulse depression was not affected by bath application of gamma-aminobutyric acid type A receptor antagonist or dopamine D1 receptor antagonist. However, low calcium and high magnesium could attenuate the paired pulse depression. These findings suggest a more complicated plasticity form in the dorsal striatum of juvenile rats that is different from that in the hippocampus, which is related with extracellular calcium.

关键词： paired pulses depression dorsal striatum calcium juvenile rats

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The acceleration of a high-charge electron bunch to 10 GeV in a 10-cm nanoparticle-assisted wakefield accelerator

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Matter and Radiation at Extremes 2024年第1期9卷 15-24页

作者： Constantin Aniculaesei Thanh Ha Samuel Yoffe Lance Labun stephen Milton Edward McCary Michael M.Spinks Hernan J.Quevedo Ou Z.Labun Ritwik Sain Andrea Hannasch Rafal Zgadzaj Isabella Pagano Jose A.Franco-Altamirano Martin L.Ringuette Erhart Gaul Scott V.Luedtke Ganesh Tiwari Bernhard Ersfeld Enrico Brunetti Hartmut Ruhl Todd Ditmire Sandra Bruce Michael E.Donovan Michael C.Downer Dino A.Jaroszynski Bjorn Manuel Hegelich University of Texas at Austin AustinTexas 78712USA SUPA Department of Physics University of StrathclydeGlasgowScotland G4 ONGUnited Kingdom Tau Systems Inc.AustinTexas 78701USA Lawrence Livermore National Laboratory LivermoreCalifornia 94550USA Los Alamos National Laboratory Los AlamosNew Mexico 87545USA Brookhaven National Laboratory UptonNew York 11973USA Ludwig-Maximilians-Universität MunichGermany

An intense laser pulse focused onto a plasma can excite nonlinear plasma *** appropriate conditions,electrons from the background plasma are trapped in the plasma wave and accelerated to ultra-relativistic *** scheme is called a laser wakefield *** this work,we present results from a laser wakefield acceleration experiment using a petawatt-class laser to excite the wakefields as well as nanoparticles to assist the injection of electrons into the accelerating phase of the *** find that a 10-cm-long,nanoparticle-assisted laser wakefield accelerator can generate 340 pC,10±1.86 GeV electron bunches with a 3.4 GeV rms convolved energy spread and a 0.9 mrad rms *** can also produce bunches with lower energies in the 4–6 GeV range.

关键词： acceleration nanoparticle charge

Kagome superconductors AV3Sb5(A = K, Rb, Cs)

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National Science Review 2023年第2期10卷 260-275页

作者： Kun Jiang Tao Wu Jia-Xin Yin Zhenyu Wang M.Zahid Hasan stephen D.Wilson Xianhui Chen Jiangping Hu Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China CAS Key Laboratory of Strongly-coupled Quantum Matter Physics Department of Physics University of Science and Technology of China Laboratory for Quantum Emergence Department of PhysicsSouthern University of Science and Technology Laboratory for Topological Quantum Matter and Advanced Spectroscopy (B7) Department of PhysicsPrinceton University Materials Department and California Nanosystems Institute University of California Santa Barbara Kavli Institute of Theoretical Sciences University of Chinese Academy of Sciences

The quasi-two-dimensional kagome materials AV3Sb5(A=K,Rb,Cs) were found to be a prime example of kagome superconductors,a new quantum platform to investigate the interplay between electron correlation effects,topology and geometric *** this review,we report recent progress on the experimental and theoretical studies of AV3Sb5and provide a broad picture of this fast-developing field in order to stimulate an expanded search for unconventional kagome *** review the electronic properties of AV3Sb5,the experimental measurements of the charge density wave state,evidence of time-reversal symmetry breaking and other potential hidden symmetry breaking in these materials.A variety of theoretical proposals and models that address the nature of the time-reversal symmetry breaking are ***,we review the superconducting properties of AV3Sb5,especially the potential pairing symmetries and the interplay between superconductivity and the charge density wave state.

关键词： kagome superconductor charge density wave time-reversal symmetry breaking topological metal

Synthesis of silicone blocked bio-polyurethane and its application in highly stretchable fiber-shaped strain sensor

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Nano Research 2023年第5期16卷 7982-7990页

作者： Zhanxu Liu Chenchen Li Xiaofeng Zhang Hongxing Xu Yanfen Zhou Mingwei Tian Shaojuan Chen stephen Jerrams Feng-Lei Zhou Liang Jiang College of Textiles and Clothing Qingdao UniversityQingdao 266071China Centre for Elastomer Research Technological University Dublin(TU Dublin)Dublin D08 NF82Ireland Centre for Medical Image Computing University College LondonLondon WC1V 6LJUK

Flexible strain sensors have become a key component of intelligent wearable ***,the fabrication of strain sensors with wide workable strain ranges and high sensitivity remains a great ***,the rapid development of polymer composites based strain sensors has produced a large amount of ***,the development of strain sensors with wide strain sensing ranges and high sensitivity based on degradable materials is *** this work,a silicone blocked polyurethane(Si-BPU)with high stretchability and degradability was synthesized and composited with carbon nanotubes(CNTs)to fabricate fibrous strain *** synthesized 0.5%Si-BPU exhibited good biodegradability with a weight loss of 16.47%in 42 *** Si-BPU/12CNTs fiber based strain sensor achieved a sensing range of 0%–353.3%strain,gauge factor(GF)of 206.3 at 250%strain and of 4,513.2 at 353.3%strain,reliable stability under 10,000 repeated stretching–releasing ***,the Si-BPU/12CNTs strain sensor showed rapid response time(<163 ms)and was capable of monitoring various human body movements(elbow bending,finger bending,breath,swallow).In consequence,this work provides a new and effective strategy for the development of sustainable wearable electronic devices.

关键词： degradability wet spinning conductivity wearable sensors

Studying the efficacy of isolation as a control strategy and elimination of tuberculosis in India:A mathematical model

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Infectious Disease Modelling 2023年第2期8卷 458-470页

作者： Archana Singh Bhadauria Hom Nath Dhungana Vinay Verma stephen Woodcock Tapan Rai Department of Mathematics and Statistics Deen Dayal Upadhyaya Gorakhpur UniversityIndia School of Mathematical and Physical Sciences University of Technology SydneyAustralia Faculty of Mathematical and Statistical Sciences Institute of Natural Sciences and HumanitiesShri Ramswaroop Memorial UniversityUttar PradeshIndia

India has the highest burden of both tuberculosis(TB)and multidrug-resistant TB(MDRTB)based on the WHO Global TB Report *** the available data suggest that the total TB incidence has declined,the absolute number of new cases is still *** number of reported TB cases in India in 2018 was 2.2 million,which was 1.5 million in *** 47%increment in TB case notification in India within a decade shows a persistent public health *** contributes about 22%of the World's TB *** National Strategic Plan 2017e2025,sets out the government plans to eliminate TB by ***,the milestone seems unrealistic to achieve the TB eradication goal by *** developed a five-dimensional mathematical model to understand the TB dynamics in India and investigate the possibility of the earliest TB eradication time *** model stratifies the entire TB class into three different classes as drug-sensitive(DS),MDR,and isolated *** effective reproduction number,equilibrium points,and stability analysis of the model were carried *** model predicts the total estimated cases of DS-TB and MDR-TB from 2018 to 2035 through numerical simulation and suggests that TB may be eliminated by 2035 in India if the treatment success rate could be achieved to 95%,by contact tracing and isolating at least 50%of MDR-TB.

关键词： Multi-drug resistant Drug-sensitive Isolation Reproduction number Mathematical modelling