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Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology

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China Foundry 2024年第1期21卷 60-70页

作者： İsmail Cem Akgün Çağın Bolat Ali gökşenli Faculty of Mechanical Engineering Istanbul Technical University34437İstanbulTurkey Faculty of Engineering Samsun University55420SamsunTurkey

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and *** this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a *** to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors *** this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF ***,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive *** results show that PEC particles can be an alternative to expensive hollow spheres used in the previous ***,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

关键词： die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation

The great catastrophe: causes of the Permo-Triassic marine mass extinction

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national Science Review 2024年第1期11卷 37-50页

作者： Paul B.Wignall david P.g.Bond School of Earth & Environment University of Leeds School of Environmental Sciences University of Hull

The marine losses during the Permo-Triassic mass extinction were the worst ever experienced. All groups were badly affected, especially amongst the benthos(e.g. brachiopods, corals, bryozoans, foraminifers,ostracods). Planktonic populations underwent a fundamental change with eukaryotic algae being replaced by nitrogen-fixing bacteria, green-sulphur bacteria, sulphate-reducing bacteria and prasinophytes. Detailed studies of boundary sections, especially those in South China, have resolved the crisis to a ～55 kyr interval straddling the Permo-Triassic boundary. Many of the losses occur at the beginning and end of this interval painting a picture of a two-phase extinction. Improved knowledge of the extinction has been supported by numerous geochemical studies that allow diverse proposed extinction mechanisms to be studied. A transition from oxygenated to anoxic-euxinic conditions is seen in most sections globally, although the intensity and timing shows regional variability. Decreased ocean ventilation coincides with rapidly rising temperatures and many extinction scenarios attribute the losses to both anoxia and high *** kill mechanisms include ocean acidification for which there is conflicting support from geochemical proxies and, even less likely, siltation(burial under a massive influx of terrigenous sediment) which lacks substantive sedimentological evidence. The ultimate driver of the catastrophic changes at the end of the Permian was likely Siberian Trap eruptions and their associated carbon dioxide emissions with consequences such as warming, ocean stagnation and acidification. Volcanic winter episodes stemming from Siberian volcanism have also been linked to the crisis, but the short-term nature of these episodes(nd the overwhelming evidence for rapid warming during the crisis makes this an unlikely cause. Finally, whilst the extinction is well studied in equatorial latitudes, a different history is found in northern Boreal latitudes

关键词： ocean anoxia ocean acidification siltation productivity collapse volcanic winter

Role of climatic variability in shaping intraspecific variation of thermal tolerance in Mediterranean water beetles

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Insect Science 2024年第1期31卷 285-298页

作者： Susana Pallarés david garoffolo Belén Rodríguez david Sánchez-Fernández Department of Zoology University of SevilleSevilleSpain Faculty of Biology Department of Ecology and HydrologyUniversity of MurciaCampus EspinardoMurciaSpain

The climatic variability hypothesis(CVH)predicts that organisms in more thermally variable environments have wider thermal breadths and higher thermal plasticity than those from more stable ***,due to evolutionary trade-offs,taxa with greater absolute thermal limits may have little plasticity of such limits(trade-off hypothesis).The CVH assumes that climatic variability is the ultimate driver of thermal tolerance variation across latitudinal and altitudinal gradients,but average temperature also varies along such *** explored intraspecific variation of thermal tolerance in three typical Mediterranean saline water beetles(families Hydrophilidae and Dytiscidae).For each species,we compared two populations where the species coexist,with similar annual mean temperature but contrasting thermal variability(continental *** population).We estimated thermal limits of adults from each population,previously acclimated at 17,20,or 25℃.We found species-specific patterns but overall,our results agree with the CVH regarding thermal ranges,which were wider in the continental(more variable)*** the two hydrophilid species,this came at the cost of losing plasticity of the upper thermal limit in this population,supporting the trade-off hypothesis,but not in the dytiscid *** results support the role of local adaptation to thermal variability and trade-offs between basal tolerance and physiological plasticity in shaping thermal tolerance in aquatic ectotherms,but also suggest that intraspecific variation of thermal tolerance does not fit a general pattern among aquatic *** such intraspecific variation could lead to inaccurate predictions of the vulnerability of aquatic insects to global warming.

关键词： acclimation capacity aquatic insects climate change heat coma temperature supercooling point thermal plasticity

Origins of perturbations in dayside equatorial ground magnetograms

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Earth and Planetary Physics 2024年第1期8卷 215-221页

作者： Syau-Yun W.Hsieh david g.Sibeck The Johns Hopkins University Applied Physics Laboratory LaurelMarylandUSA nASA goddard Space Flight Center GreenbeltMarylandUSA

To determine the cause(s)of perturbations seen in dayside equatorial ground magnetograms,we conducted a systematic survey of simultaneous ground-based and geosynchronous satellite-based observations during the 90-day period from December 1,2020 to February 28,*** examined Huancayo ground magnetometer observations from 14:00:00 to 20:00:00 UT each day,during which Huancayo passed through local *** those data we chose perturbation events selected on the basis of large(>20 nT)event amplitude and classified the selected events as responding primarily to solar wind pressure,or to variations in the north/south component of the interplanetary magnetic field(IMF Bz),or perhaps in part to *** results show that an equivalent number of events were identified for each model during this 90-day *** in the lagged solar wind dynamic pressure routinely correspond to nearly simultaneous sudden impulses recorded at both geosynchronous orbit and on the *** in IMF Bz produce erosion signatures at geosynchronous orbit and can correspond to ground events if lag times for reconnection to enhance convection in the magnetosphere are taken into account.

关键词： dayside magnetosphere dayside equatorial ionosphere geosynchronous magnetic field

A multi-sensor appiproach to calving detection

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Information Processing in Agriculture 2024年第1期11卷 45-64页

作者： Anita Z.Chang david L.Swain Mark g.Trotter Institute for Future Farming Systems School of HealthMedicaland Applied SciencesCentral Queensland UniversityRockhamptonQueensland 4700Australia

The advent of remote livestock monitoring systems provides numerous possibilities for improving on-farm productivity,efficiency,and *** potential application for these systems is for the detection of calving *** study describes the integration of data from multiple sensor sources,including accelerometers,global navigation satellite systems(gnsS),an accelerometer-derived rumination algorithm,a walk-over-weigh unit,and a weather station for parturition detection using a support vector machine *** best performing model utilised data from gnsS,the ruminating algorithm,and weather stations to achieve 98.6%accuracy,with 88.5%sensitivity and 100%*** topranking features of this model were primarily gnSS *** study provides an overview as to how various sensor systems could be integrated on-farm to maximise calving detection for improved production and welfare outcomes.

关键词： Accelerometer gnSS gPS Rumination Sensor WOW

Finding the magnetopause location using soft X-ray observations and a statistical inverse method

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Earth and Planetary Physics 2024年第1期8卷 184-203页

作者： gonzalo Cucho-Padin Hyunju Connor Jaewoong Jung Brian Walsh david g.Sibeck Space Weather Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Department of Physics The Catholic University of AmericaWashingtonDCUSA geospace Physics Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Astronomy Department University of Maryland College ParkCollege ParkMDUSA Center for Space Physics Department of Mechanical EngineeringBoston UniversityBostonMAUSA

Variability in the location and shape of the dayside magnetopause is attributed to magnetic reconnection,a fundamental process that enables the transfer of mass,energy,and momentum from the solar wind into the *** spatial and temporal properties of the magnetopause,under varying solar and magnetospheric conditions,remain largely unknown because empirical studies using in-situ observations are challenging to *** wide field-of-view(FOV)imaging is the only means to simultaneously observe the spatial distribution of the plasma properties over the vast dayside magnetospheric region and,subsequently,quantify the energy transport from the interplanetary medium into the terrestrial *** upcoming missions,ESA/CAS SMILE and nASA’s LEXI will provide wide-field imagery of the dayside magnetosheath in soft X-rays,an emission generated by charge exchange interactions between high charge-state heavy ions of solar wind origin and exospheric neutral ***-cadence two-dimensional observations of the magnetosheath will allow the estimation of dynamic properties of its inner boundary,the magnetopause,and enable studies of its response to changes in the solar wind dynamic pressure and interplanetary magnetic field *** work introduces a statistically-based estimation approach based on inverse theory to estimate the spatial distribution of magnetosheath soft X-ray emissivities and,with this,identify the location of the magnetopause over the Sun−Earth *** do so,we simulate the magnetosheath structure using the MHD-based OpenggCM model and generate synthetic soft X-ray images using LEXI’s orbit and attitude *** results show that 3-D estimations using the described statistically-based technique are robust against Poisson-distributed shot noise inherent to soft X-ray ***,our proposed methodology shows that the accuracy of both three-dimensional(3-D)estimation and the magnetopause standoff distance calculation hi

关键词： magnetopause soft X-ray tomography

Corneal and intraocular pressure changes associated to the circadian rhythms:a narrative review

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International Journal of Ophthalmology(English edition) 2024年第10期17卷 1921-1928页

作者： Laura Barberán-Bernardos MiguelÁngel Ariza-gracia david P Piñero Department of Optics Pharmacology and AnatomyUniversity of AlicanteSan Vicente del Raspeig 03690AlicanteSpain ARTORg Center for Biomedical Engineering Research University of BernBern 3008Switzerland Department of Ophthalmology(IMQO-Oftalmar) Vithas Medimar International HospitalAlicante 03016Spain

AIM:To synthesize the current body of research regarding the diurnal variations in intraocular pressure(IOP)and corneal biomechanical and morphological parameters,highlighting their significance in various eye ***:A comprehensive review of studies on the diurnal variations of IOP and corneal parameters was *** findings from various studies were assessed,including the goldmann applanation tonometry(gAT)and non-contact *** on the variations in central corneal thickness(CCT),corneal curvature,and corneal biomechanics measured by the Ocular Response Analyzer system across different population groups was extracted and ***:In both healthy subjects and those with Fuchs dystrophy,IOP and CCT demonstrate marked diurnal *** remains the gold standard for tonometry,with the highest ***,its measurements are influenced by *** patients and those with pseudoexfoliation showed significant diurnal variations in *** biomechanical parameters,especially corneal hysteresis(CH)and the corneal resistance factor(CRF),largely remain stable throughout the day for most of eye conditions,with some ***,the corneal morphology diurnal variation,particularly curvature,yielded mixed conclusions across ***:Circadian rhythms significantly influence various corneal parameters,most notably IOP and *** studies should emphasize standardized approaches larger sample sizes,and delve deeper into less-explored areas,such as the effects of orthokeratology lenses on diurnal biomechanical shifts.

关键词： circadian rhythms intraocular pressure corneal thickness corneal biomechanics corneal curvature

Airway management of a patient with linear immunoglobulin A bullous dermatosis:A case report

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World Journal of Clinical Cases 2024年第13期12卷 2263-2268页

作者： Olga C nin Robert Hutnik neil n Chheda david Hutchinson Department of Anesthesiology University of Florida College of MedicineGainesvilleFL 32610United States Department of Otolaryngology University of Florida College of MedicineGainesvilleFL 32610United States

BACKgROUnD There is limited literature on managing the airway of patients with linear immunoglobulin A(IgA)bullous dermatosis,a rare mucocutaneous disorder that leads to the development of friable *** clinical decision making is necessary when there is a risk of bleeding into the airway,and a multidisciplinary team approach may lead to decreased patient morbidity during these high-risk scenarios,especially when confronted with an unusual cause for *** SUMMARY A 45-year-old African American female presented to our ambulatory surgical center for right corneal transplantation due to corneal perforation after blunt trauma in the setting of cicatricial conjunctivitis and diffuse corneal neovascularization from linear IgA bullous *** diagnosis of IgA dermatosis was recent,and the patient had been lost to *** severity of the disease and extent of airway involvement was unknown at the time of the *** airway bleeding was noticed upon intubation and the otorhinolaryngology team had to be called to the operating *** patient required transfer to the intensive care unit where a multidisciplinary team was involved in her *** patient was extubated on postoperative day *** A multidisciplinary approach to treating this disease is the best course of action before a surgical *** our case,key communication between the surgery,anesthesia,and dermatology teams led to the quick and safe treatment of our patient’s *** surgery should not be considered for these cases unless they are in full remission and there is no mucous membrane involvement.

关键词： Airway management Bleeding risk Linear immunoglobulin A bullous dermatosis Multidisciplinary approach Outpatient procedure Case report

Structural changes in the obese brain

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neural Regeneration Research 2024年第12期19卷 2561-2562页

作者： Anna R.R.Da Conceicao Marcelo n.n.Vieira Fernanda g.De Felice D’Or Institute for Research and Education Rio de JaneiroBrazil Institute of Medical Biochemistry Leopoldo De Meis Federal University of Rio de JaneiroRio de JaneiroBrazil Centre for neuroscience Studies Department of Biomedical and Molecular Sciences&Department of PsychiatryQueen’s UniversityKingstonONCanada

Obesity represents a major global health concern,with widespread growing prevalence and severe consequences for the quality of life and life expectancy of affected individuals and for the economic burden of healthcare systems(Prospective Studies Collaboration,2009).Obesity is a well-established risk factor for a variety of conditions including metabolic,vascula r,and heart diseases,and seve ral types of cancer(Prospective Studies Collaboration,2009).

关键词： diseases consequences prevalence