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CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and Pt)

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journal of Rare earths 2024年第9期42卷 1669-1681,I0002页

作者： j.C.Martínez-Munuera M.P.Yeste A.García-García MCMA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of AlicanteCarretera de San Vicente del Raspeig s/n03690San Vicente del RaspeigAlicanteSpain Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of CádizAp.40E-11510Puerto RealCádizSpain

In this work,several ceria-zirconia based catalysts with very lo w(and equimolar) metal contents were prepared,characterised and tested for the CO oxidatio n reaction(under lean and stoichiometric conditions),trying to emulate those conditions found in a diesel oxidation catalyst(DOC) system from a diesel engine and those encountered under gasoline exhaust(λ=1).The metals chosen are Cu,Co,Ag and Pt(as a reliable benchmark).The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion(Ag-catalyst seems to present a low level of dispersion).This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H_(2)-TPR ***,the order in catalytic activity(Cu>Ag>Co≈Pt>>support) seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce_(0.8)Zr_(0.2)O_(2)-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H_(2)-TPR measurements.

关键词： CO oxidation Low metal content Ceria-zirconia Copper species OSC parameter Rare earths

Three-dimensional magnetization reconstruction from electron optical phase images with physical constraints

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 122-132页

作者： Boyao Lyu Shihua Zhao Yibo Zhang Weiwei Wang Fengshan Zheng Rafal e.Dunin-Borkowski jiadong Zang Haifeng Du Anhui Province Key Laboratory of Low-energy Quantum Materials and Devices High Magnetic Field LaboratoryHefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China Science Island Branch Graduate School of University of Science and Technology of ChinaHefei 230026China Department of Physics and Astronomy University of New HampshireDurham 03824USA Department of Physics The City College of New YorkNew York 10031USA Physics Program Graduate Center of the City University of New YorkNew York 10016USA Department of Chemistry University of New HampshireDurham 03824USA Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China Spin-X Institute Center for Electron MicroscopySchool of Physics and OptoelectronicsState Key Laboratory of Luminescent Materials and DevicesGuangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional MaterialsSouth China University of TechnologyGuangzhou 511442China ernst Ruska-Centre for Microscopy and Spectroscopy with electrons Forschungszentrum JülichJülich 52425Germany

The ability to characterize three-dimensional(3D)magnetization distributions in nanoscale magnetic materials and devices is essential to fully understand their static and dynamic magnetic *** contrast techniques in the transmission electron microscope(TeM),such as electron holography and electron ptychography,can be used to record two-dimensional(2D)projections of the in-plane magnetic induction of 3D nanoscale *** the 3D magnetic induction can in principle be reconstructed from one or more tilt series of such 2D projections,conventional tomographic reconstruction algorithms do not recover the 3D magnetization within a sample ***,we use simulations to describe the basis of an improved model-based algorithm for the tomographic reconstruction of a 3D magnetization distribution from one or more tilt series of electron optical phase images recorded in the *** algorithm allows a wide range of physical constraints,including a priori information about the sample geometry and magnetic parameters,to be *** also makes use of minimization of the micromagnetic energy in the loss *** demonstrate the reconstruction of the 3D magnetization of a localized magnetic soliton—a hopfion ring—and discuss the influence of noise,choice of magnetic constants,maximum tilt angle and number of tilt axes on the *** algorithm can in principle be adapted for other magnetic contrast imaging techniques in the TeM,as well as for other magnetic characterization techniques,such as those based on X-rays or neutrons.

关键词： three-dimensional magnetization vector field tomography differentiable programming electron holography micromagnetism

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Dynamic convergent shock compression initiated by return current in high-intensity laser-solid interactions

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Matter and Radiation at extremes 2024年第4期9卷 40-53页

作者： Long Yang Martin Rehwald Thomas Kluge Alejandro LasoGarcia Toma Toncian Karl Zeil Ulrich Schramm Thomas e.Cowan Lingen Huang Helmholtz-Zentrum Dresden-Rossendorf 01328 DresdenGermany Technische Universitat Dresden 01062 DresdenGermany

We investigate the dynamics of convergent shock compression in solid cylindrical targets irradiated by an ultrafast relativistic laser *** particle-in-cell simulations and coupled hydrodynamic simulations reveal that the compression process is initiated by both magnetic pressure and surface ablation associated with a strong transient surface return current with density of the order of 10^(17) A/m^(2) and lifetime of 100 *** results show that the dominant compression mechanism is governed by the plasma β,i.e.,the ratio of thermal pressure to magnetic *** targets with small radius and low atomic number Z,the magnetic pressure is the dominant shock compression *** to a scaling law,as the target radius and Z increase,the surface ablation pressure becomes the main mechanism generating convergent ***,an indirect experimental indication of shocked hydrogen compression is provided by optical shadowgraphy measurements of the evolution of the plasma expansion *** results presented here provide a novel basis for the generation of extremely high pressures exceeding Gbar(100 TPa)to enable the investigation of high-pressure physics using femtosecond j-level laser pulses,offering an alternative to nanosecond kj-laser pulse-driven and pulsed power Z-pinch compression methods.

关键词： shock convergent return

Characterization of bright betatron radiation generated by direct laser acceleration of electrons in plasma of near critical density

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Matter and Radiation at extremes 2024年第2期9卷 26-35页

作者： j.Cikhardt M.Gyrdymov S.Zähter P.Tavana M.M.Günther N.Bukharskii N.Borisenko j.jacoby X.F.Shen A.Pukhov N.e.Andreev O.N.Rosmej Faculty of electrical engineering Czech Technical University in Prague16627 Prague 6Czech Republic Goethe University FrankfurtMax-von-Laue-Straße 160438 Frankfurt am MainGermany GSI Helmholtzzentrum für Schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany Focused energy GmbH Im Tiefen See 4564293 DarmstadtGermany National Research Nuclear University MePhI Kashirskoe shosse 31115409 MoscowRussian Federation Lebedev Physical Institute RAS Leninskiy Prospekt 53119991 MoscowRussian Federation Heinrich-Heine-University Düsseldorf Universitätsstrasse 1DüsseldorfGermany joint Institute for High Temperatures RASIzhorskaya st.13Bldg.2125412 MoscowRussian Federation Moscow Institute of Physics and Technology Institutskiy Pereulok 9141700 DolgoprudnyRussia

Directed x-rays produced in the interaction of sub-picosecond laser pulses of moderate relativistic intensity with plasma of near-critical density are investigated. Synchrotron-like (betatron) radiation occurs in the process of direct laser acceleration (DLA) of electrons in a relativisticlaser channel when the electrons undergo transverse betatron oscillations in self-generated quasi-static electric and magnetic fields. In anexperiment at the PHeLIX laser system, high-current directed beams of DLA electrons with a mean energy ten times higher than the ponderomotive potential and maximum energy up to 100 MeV were measured at 10^(19) W/cm^(2)laser intensity. The spectrum of directed x-raysin the range of 5–60 keV was evaluated using two sets of Ross filters placed at 0°and 10°to the laser pulse propagation axis. The differential x-ray absorption method allowed for absolute measurements of the angular-dependent photon fluence. We report 10^(13) photons/sr withenergies >5 keV measured at 0°to the laser axis and a brilliance of 10^(21) photons s^(−1) mm^(−2) mrad−2(0.1%BW)−1. The angular distributionof the emission has an FWHM of 14°–16°. Thanks to the ultra-high photon fluence, point-like radiation source, and ultra-short emissiontime, DLA-based keV backlighters are promising for various applications in high-energy-density research with kilojoule petawatt-class laserfacilities.

关键词： laser acceleration critical

Blood Pressure Profile and Glycemic Control of Type 2 Diabetics and Hypertensives at the Yalgado Ouedraogo University Hospital: A Review of 116 Cases

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World journal of Cardiovascular Diseases 2024年第1期14卷 61-76页

作者： G. R. C. Millogo A. Thiam Y. Kambiré e. Nongkouni S. e. Dabiré L. j. Kagambéga j. K. Kologo V. N. Yaméogo P. Zabsonré Department of Cardiology Yalgado Ouédraogo University Hospital Ouagadougou Burkina Faso Department of Cardiology Tengandogo University Hospital Ouagadougou Burkina Faso

Objective: The association hypertension and diabetes is important. The two pathologies may influence each other. The aim was to study the correlation between glycemic control and blood pressure control and to determine the factors associated with blood pressure control. Methodology: This was a descriptive cross-sectional study with an analytical focus over 7 months. Patients were recruited as outpatients and all underwent ambulatory blood pressure measure, glycated hemoglobin and creatinine measurements, and assessment of compliance with treatment. Results: During this period 116 patients were collected. The predominance was female 69%. The mean age of the patients was 62 ± 7 years with a peak between 60 and 70 years. The average age of hypertension was 12 years and that of diabetes 6 1/2 years. The most frequently associated cardiovascular risk factor was a sedentary lifestyle (71.5%) after age. 57.8% of patients were not controlled at the office, with a predominance of systolic hypertension (58.2%). 61.6% of patients were controlled by ambulatory blood pressure measure, a rate of 47.8% of white coat hypertension. Glycemic control was observed in 42.2% of cases and 87% of patients had good renal function (glomerular filter rate ≥ 60 ml/mn). Therapeutic compliance was good in 53.4% of cases and dual therapy was the most used therapeutic modality 44.8% (52 patients) followed by triple therapy. The factors associated with poor blood pressure control were glycemic imbalance, non-compliance and monotherapy. Dual therapy had a protective effect. Conclusion: The association of hypertension and type 2 diabetes is frequent. The risk of occurrence increases with age. Ambulatory blood pressure measure is the best method to assess blood pressure control. Optimization of blood pressure control should also include optimization of glycemic control.

关键词： Blood Pressure Control Glycemic Control Hypertensive and Diabetic Patients

Why ecosystem characteristics predicted from remotely sensed data are unbiased and biased at the same time-and how this affects applications

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Forest ecosystems 2024年第1期11卷 24-31页

作者： Goran Ståhl Terje Gobakken Svetlana Saarela Henrik j.Persson Magnus ekstrom Sean P.Healey Zhiqiang Yang johan Holmgren eva Lindberg Kenneth Nystrom emanuele Papucci Patrik Ulvdal Hans OleØrka erik Næsset Zhengyang Hou Håkan Olsson Ronald e.McRoberts Department of Forest Resource Management Swedish University of Agricultural Sciences90183UmeåSweden Faculty of environmental Sciences and Natural Resource Management Norwegian University of Life SciencesÅsNorway USDA Forest Service Rocky Mountain Research StationOgdenUTUSA The Key Laboratory for Silviculture and Conservation of Ministry of education Beijing Forestry UniversityBeijing100083China Department of Forest Resources University of MinnesotaSt.PaulMNUSA

Remotely sensed data are frequently used for predicting and mapping ecosystem characteristics,and spatially explicit wall-to-wall information is sometimes proposed as the best possible source of information for ***,wall-to-wall information typically relies on model-based prediction,and several features of model-based prediction should be understood before extensively relying on this type of *** such feature is that model-based predictors can be considered both unbiased and biased at the same time,which has important implications in several areas of *** this discussion paper,we first describe the conventional model-unbiasedness paradigm that underpins most prediction techniques using remotely sensed(or other)auxiliary *** this point of view,model-based predictors are typically ***,we show that for specific domains,identified based on their true values,the same model-based predictors can be considered biased,and sometimes severely *** suggest distinguishing between conventional model-bias,defined in the statistical literature as the difference between the expected value of a predictor and the expected value of the quantity being predicted,and design-bias of model-based estimators,defined as the difference between the expected value of a model-based estimator and the true value of the quantity being *** show that model-based estimators(or predictors)are typically design-biased,and that there is a trend in the design-bias from overestimating small true values to underestimating large true ***,we give examples of applications where this is important to acknowledge and to potentially make adjustments to correct for the design-bias *** argue that relying entirely on conventional model-unbiasedness may lead to mistakes in several areas of application that use predictions from remotely sensed data.

关键词： Bias Model-based inference Design-based inference

Gut microbiota modulating intestinal stem cell differentiation

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World journal of Stem Cells 2024年第6期16卷 619-622页

作者： Lin He Chen Zhu Xiang-Feng Zhou Shu-e Zeng Le Zhang Kuan Li Department of Alcohol and Drug Dependence Treatment The Mental Hospital of Yunnan ProvinceKunming 650224Yunnan ProvinceChina Department of Physical education Kunming Medical UniversityKunming 650500Yunnan ProvinceChina Department of Geriatric Psychiatry The Mental Hospital of Yunnan ProvinceKunming 650224Yunnan ProvinceChina Sleep Medicine Center The Mental Hospital of Yunnan ProvinceKunming 650224Yunnan ProvinceChina

Proliferation and differentiation of intestinal stem cell(ISC)to replace damaged gut mucosal epithelial cells in inflammatory states is a critical step in ameliorating gut ***,when this disordered proliferation continues,it induces the ISC to enter a cancerous *** gut microbiota on the free surface of the gut mucosal barrier is able to interact with ISC on a sustained ***-biota metabolites are able to regulate the proliferation of gut stem and progenitor cells through transcription factors,while in steady state,differentiated colono-cytes are able to break down such metabolites,thereby protecting stem cells at the gut *** the future,the gut flora and its metabolites mediating the regulation of ISC differentiation will be a potential treatment for enteropathies.

关键词： Intestinal stem cells Gut microbiota Gut stem niche Microenvironment Probiotics

Lighting up aggregate emission of perylene diimide by leveraging polymerization-mediated through-space charge transfer and π-π stacking

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Science China Chemistry 2024年

作者： Suiying Ye Désirée Füglistaller Tian Tian Anjay Manian Sudhir Kumar Celine Nardo Andrew j.Christofferson Salvy P.Russo Chih-jen Shih jean-Christophe Leroux Yinyin Bao Institute of Pharmaceutical Sciences Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 3 Institute for Chemical and Bioengineering Department of Chemistry and Applied Biosciences ETH Zurich Vladimir-Prelog-Weg 1-5 ARC Centre of excellence in exciton Science School of Science RMIT University School of Science STEM College RMIT University

The molecular engineering of fluorescent organic/polymeric materials, specifically those emitting in the deep red to near-infrared spectrum, is vital for advancements in optoelectronics and biomedicine. Perylene diimide(PDI), a well-known fluorescent scaffold, offers high thermal and photophysical stability but suffers from fluorescence quenching in solid or aggregate states due to intense π-π interactions. To mitigate this, simple and versatile methods for strong PDI aggregate emission without extensive synthetic demands are highly desirable but still lacking. Here, we report a straightforward strategy to enhance the solid-state emission of PDI by introducing certain degree of through-space charge transfer(TSCT) via controlled radical polymerization,which can efficiently distort the typical face-to-face PDI stacking, enabling greatly enhanced deep red emission. This is achieved by growing electron-donating star-shape styrenic(co)polymers from a multidirectional electron-accepting PDI initiator. The incorporation of polycyclic aromatic monomers further shifted the emission into the near-infrared region, albeit with a reduced intensity. Overall, the emission of the PDI-based TSCT polymers can be systematically manipulated by leveraging the balance between PDI stacking and the TSCT degree, as confirmed by both experimental study and theoretical calculations. Our approach circumvents complex synthetic procedures, offering highly emissive materials with large Stokes shifts and showing broad potential for optoelectronic technology.

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A new approach to pedestal differentiation for soil loss estimation-a case study from a burnt area in north-central Portugal

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journal of Forestry Research 2024年第3期35卷 45-54页

作者： Frank G.A.Verheijen Martinho A.S.Martins Sergio A.Prats jan j.Keizer Centre for environmental and Marine Studies(CeSAM) Department Environment and PlanningUniversity of Aveiro3810-193 AveiroPortugal Mediterranean Institute for Agriculture Environment and Development(MED-CHANGE)Institute for Advanced Studies and ResearchUniversity of EvoraPolo da MitraAp.947006-554 EvoraPortugal GeoBiociencias Geotecnologias E Geoengenharias(GEOBIOTEC)Department Environment and PlanningUniversity of Aveiro3810-193 AveiroPortugal

Soil pedestals have long been used as qualitative indicators of soil splash *** rangelands,plant-capped pedestals,generally grass tussocks,have also been used to quantitatively estimate soil loss since the first half of the twentieth *** agricultural lands,forests,and bad-lands,stone-capped pedestals have been used as qualitative and semi-quantitative indicators of active,'extreme'*** work has been reported on using capstone pedestal data for quantifying soil *** postulate that three distinct capstone pedestal types may be present in any given location and that a detailed analysis of a pedestal height histogram may be used to recognize their *** analysis can subsequently inform if soil loss can be reliably estimated and if so,which of the existing methods using pedestal height data will provide more accurate *** three proposed capstone pedestal types are:(1)neo-pedestals formed underneath surface stones exposed by(partial)removal of the soil surface cover;(2)endo-pedestals formed underneath stones that were buried in the soil but have been exposed by erosion;and(3)phoenix-pedestals formed underneath stones from collapsed *** the pedestal height histogram of any given location,a skew to smaller heights may indicate the existence of endo-and/or phoenix-pedestals,which may be revealed as a bi-(or tri)modal distribution when using a smaller bin *** concept was applied to a case study where soil loss had been monitored for control plots and mulched plots during a 5-year period following wildfire in a eucalypt *** measured pedestal heights and used methods to quantitatively assess soil loss from soil pedestal data in the available *** pedestal data at the end of the 5-year period under or overestimated soil loss in the control treatment,with results ranging from 60 to 115%of measured soil loss,depending on the *** is postulated that phoenix-and endo-pedestals may be a driving fact

关键词： Soil pedestals Mulch Wildfire Soil erosion Char