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First demonstration of an all-solid-state optical cryocooler

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Light(Science & Applications) 2018年第1期7卷 922-931页

作者： Markus P.Hehlen Junwei Meng alexander r.albrecht Eric r.Lee Aram Gragossian Steven P.Love Christopher E.Hamilton richard I.Epstein Mansoor Sheik-Bahae Los Alamos National Laboratory P.O.Box 1663Los AlamosNM 87545USA Department of Physics&Astronomy University of New MexicoAlbuquerqueNM 87131USA

Solid-state optical refrigeration uses anti-Stokes fluorescence to cool macroscopic objects to cryogenic temperatures without *** such as Yb3+-doped YLiF4(YLF:Yb)have previously been laser-cooled to 91 *** this study,we show for the first time laser cooling of a payload connected to a cooling crystal.A YLF:Yb crystal was placed inside a Herriott cell and pumped with a 1020-nm laser(47 W)to cool a HgCdTe sensor that is part of a working Fourier Transform Infrared(FTIr)spectrometer to 135 *** first demonstration of an all-solid-state optical cryocooler was enabled by careful control of the various desired and undesired heat *** heating of the payload was minimized by using a single-kink YLF thermal link between the YLF:Yb cooling crystal and the copper coldfinger that held the HgCdTe *** adhesive-free bond between YLF and YLF:Yb showed excellent thermal *** laser-cooled assembly was then supported by silica aerogel cylinders inside a vacuum clamshell to minimize undesired conductive and radiative heat loads from the warm *** structure can serve as a baseline for future optical cryocooler devices.

关键词： optical pumped desired

Exploring factors of disaster preparedness in UNESCO-designated heritage sites

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Geography and Sustainability 2024年第3期5卷 392-404页

作者： Emmanuel Eze alexander Siegmund Institute of Geography&Heidelberg Center for the Environment(HCE) University of HeidelbergHeidelbergGermany Department of Geography-research Group for Earth Observation(r geo) UNESCO Chair on Observation and Education of World Heritage&Biosphere ReserveHeidelberg University of EducationHeidelbergGermany Geographical and Environmental Education Unit Department of Social Science EducationUniversity of NigeriaNsukkaNigeria

Increased hazards threatening the United Nations Educational,Scientific and Cultural Organization(UNESCO)-designated sites and endangering cultural heritage and community well-being require attention and ***-sidering the pivotal role of UNESCO sites in conservation and development,this study assessed their levels of disaster *** absence of studies assessing disaster awareness,risk perception,and preparedness among UNESCO site actors,as well as the pivotal place of preparedness within the Disaster risk Management(DrM)cycle justifies this *** the tenets of the Person-relative-to-Event framework,we hypothe-sized that a strong positive correlation exists between perceived risks,resources,and disaster *** collect pertinent data,we employed an embedded mixed-method design and conducted an online questionnaire survey yielding 141 responses from 59 *** the results of relevant analyses,wildfires,floods,and droughts are top hazards occurring frequently in UNESCO sites,with significant concerns about pollution and habitat loss during future *** emerged as the most available crucial DrM resource,with higher availability of DrM resources correlating positively and significantly with sites’*** findings con-tribute valuable insights to address missing links for disaster-ready and resilient UNESCO sites,promoting their preservation for future generations.

关键词： Biosphere reserves Disaster risk management(DrM) Global geoparks Person-relative-to-event(PrE)framework Sustainability World heritage sites

Scanning transmission electron microscopy and atom probe tomography analysis of non-stoichiometry long-period-stacking-ordered structures in Mg-Ni-Y/Sm alloys

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Journal of Magnesium and Alloys 2024年第3期12卷 954-965页

作者： Yimeng Chen Manuel Legrée Jean-Louis Bobet alexander Kvit CAMECA Instruments Inc MadisonWI 53711USA ICMCB Universitéde BordeauxPessacCEDEX 33608France NIAC&Materials Science Department University of WisconsinMadisonWI 53706USA

The long-period-stacking-ordered(LPSO)structure affects the mechanical,corrosion and hydrolysis properties of Mg *** current work employs high angle annular dark field-scanning transmission electron microscopy(HAADF-STEM)and atom probe tomography(APT)to investigate the structural and local chemical information of LPSO phases formed in Mg-Ni-Y/Sm ternary alloys after extended isothermal *** on the alloying elements and their concentrations,Mg-Ni-Y/Sm develops a two-phase LPSO+α-Mg structure in which the LPSO phase contains defects,hybrid LPSO structure,and Mg ***-STEM and APT indicate non-stoichiometric LPSO with incomplete Ni_(6)(Y/Sm)_(8) *** addition,the APT quantitatively determines the local composition of LPSO and confirms the presence of Ni within the Mg bonding *** results provide insight into a better understanding of the structure and hydrolysis properties of LPSO-Mg alloys.

关键词： Magnesium alloys Long-range ordering Atom probe tomography(APT) STEM HAADF Hydrolysis properties.

Mammal-bearing Pleistocene deposits,Vranic,southwestern Pannonian Basin System

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Journal of Palaeogeography 2024年第3期13卷 430-452页

作者： Adriano Banak Zsòfia ruszkiczay-rüdiger Anita Grizelj Martina Đuras Kresimir Petrinjak ASTEr Team alexander Wieser Monika Milosevic Davor Pavelic Department of Geology Croatian Geological SurveyMilana Sachsa 2HR-10000 ZagrebCroatia Institute for Geological and Geochemical research HUN-REN Research Centre for Astronomy and Earth Sciences(MTA Centre of Excellence)Budaorsi Street 451112 BudapestHungary The Faculty of Veterinary Medicine University of ZagrebHeinzelova 55HR-10000 ZagrebCroatia CErEGE CNRS-IRD-College de France-INRAE UM34Aix-Marseille UniversiteAix-en-ProvenceFrance Faculty of Physics-Isotope Physics University of ViennaWahringer Straße 171090 ViennaAustria Faculty of Mining Geology and Petroleum EngineeringUniversity of ZagrebPierottijeva 6HR-10000 ZagrebCroatia

Vranic site is a sand quarry that is located on the southern foothills of Papuk *** bottom to top of the succession,three sedimentary units have been recognized as:Unit 1 containing massive sand with scattered gravel-sized clasts,marl cobbles and boulders,and abundant marine mammal and fish fossils;Unit 2 consisting of sand intercalated with silt,clay and gravel,which may be horizontally bedded;and Unit 3,which is an erosionally-based lenticular matrix to clast-supported structureless *** basal part of Unit 1 shows numerous reworked skeletal remains of Miocene marine *** radionuclides constrain the age of burial of Unit 1 to 895±211 ka,while the source area of Unit 1 had a quick *** massive sands deposited on the slopes of Papuk Mountain were vulnerable to erosion due to the absence of *** rainfall or water from snow melting created flash floods that infiltrated the sands,thereby causing slope destabilization and *** process led to slumps that were transformed into a sandy debris *** sediment was probably deposited during the interglacial marine isotope age(MIS)21 period when the scarce vegetation and a warmer climate favored the melting of permafrost ice and consequently triggered slope movements during MIS *** reworked skeletal material sampled at the Vranic site comprises fossilized fish along with mammal bones and ***,the Vranic site represents an important site for cetacean fossil remains and serves as an important data source for marine life in the Central Paratethys.

关键词： Miocene marine mammals Alluvial slope deposit Pleistocene Cosmogenic nuclides Pannonian Basin System

Optical probing of ultrafast laser-induced solid-to-overdense-plasma transitions

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Light(Science & Applications) 2024年第5期13卷 973-984页

作者： Yasmina Azamoum Georg alexander Becker Sebastian Keppler Guillaume Duchateau Stefan Skupin Mickael Grech Fabrice Catoire Sebastian Hell Issa Tamer Marco Hornung Marco Hellwing alexander Kessler Franck Schorcht Malte Christoph Kaluza GSI Helmholtzzentrum für Schwerionenforschung Planckstr.164291 DarmstadtGermany. Helmholtz Institute Jena Fröbelstieg 307743 JenaGermany. Institute of Optics and Quantum Electronics Friedrich-SchillerUniversität JenaMax-Wien-Platz 107743 JenaGermany. CEA-CESTA 15 Avenue des SablièresCS6000133116 Le BarpCedexFrance Institut Lumière Matière UMR 5306-CNRSUniversitéde Lyon 169622 VilleurbanneFrance. LULI CNRSCEASorbonne UniversitéInstitut Polytechnique de ParisPalaiseauFrance. Universitéde Bordeaux-CNrS-CEA CELIAUMR 5107 TalenceFrance

Understanding the solid target dynamics resulting from the interaction with an ultrashort laser pulse is a challenging fundamental multi-physics problem involving atomic and solid-state physics,plasma physics,and laser *** of the initial interplay of the underlying processes is essential to many applications ranging from lowpower laser regimes like laser-induced ablation to high-power laser regimes like laser-driven ion *** the properties of the so-called pre-plasma formed as the laser pulse’s rising edge ionizes the target is complicated from the theoretical and experimental point of view,and many aspects of this laser-induced transition from solid to overdense plasma over picosecond timescales are still open *** the one hand,laser-driven ion acceleration requires precise control of the pre-plasma because the efficiency of the acceleration process crucially depends on the target properties at the arrival of the relativistic intensity peak of the *** the other hand,efficient laser ablation requires,for example,preventing the so-called“plasma shielding”.By capturing the dynamics of the initial stage of the interaction,we report on a detailed visualization of the pre-plasma formation and ***-thin diamond-like carbon foils are shown to transition from solid to plasma during the laser rising edge with intensitiesr-infrared probe transmission measurements evidence sub-picosecond dynamics of an expanding plasma with densities above 10^(23)cm^(−3)(about 100 times the critical plasma density).The complementarity of a solid-state interaction model and kinetic plasma description provides deep insight into the interplay of initial ionization,collisions,and expansion.

关键词： laser acceleration solid

A new perspective on intervertebral disc calcification—from bench to bedside

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Bone research 2024年第1期12卷 50-61页

作者： Emanuel J.Novais rajkishen Narayanan Jose A.Canseco Koen van de Wetering Christopher K.Kepler Alan S.Hilibrand alexander r.Vaccaro Makarand V.risbud Department of Orthopaedic Surgery Sidney Kimmel Medical CollegeThomas Jefferson UniversityPhiladelphiaPAUSA Unidade Local de Saúde do Litoral Alentejano Orthopedic DepartmentSantiago do CacémPortugal rothman Orthopedic Institute at Thomas Jefferson University PhiladelphiaPAUSA

Disc degeneration primarily contributes to chronic low back and neck ***,there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis,ectopic calcification,herniation,or mixed *** these phenotypes,disc calcification is the least *** calcification,by definition,is the pathological mineralization of soft tissues,widely studied in the context of conditions that afflict vasculature,skin,and ***,disc calcification is associated with poor surgical outcomes and back pain refractory to conservative *** is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular and morphological characteristics:hypertrophic chondrocyte-like cell differentiation;TNAP,ENPP1,and ANK upregulation;cell death;altered Pi and PPi homeostasis;and local *** studies in mouse models have provided a better understanding of the mechanisms underlying this *** is essential to recognize that the presentation and nature of mineralization differ between AF,NP,and EP ***,the combination of anatomic location,genetics,and environmental stressors,such as aging or trauma,govern the predisposition to ***,the systemic regulation of calcium and Pi metabolism is less important than the local activity of PPi modulated by the ANK-ENPP1 axis,along with disc cell death and differentiation *** there is limited understanding of this phenotype,understanding the molecular pathways governing local intervertebral disc calcification may lead to developing disease-modifying drugs and better clinical management of degeneration-related pathologies.

关键词： degeneration metabolism intervertebral

Convergent Data-Driven regularizations for CT reconstruction

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Communications on Applied Mathematics and Computation 2024年第2期6卷 1342-1368页

作者： Samira Kabri alexander Auras Danilo riccio Hartmut Bauermeister Martin Benning Michael Moeller Martin Burger Helmholtz Imaging Deutsches Elektronen-Synchrotron DESYNotkestr.8522607 HamburgGermany Institute for Vision and Graphics University of SiegenAdolf-Reichwein-Straße 2a57076 SiegenGermany School of Mathematical Sciences Queen Mary University of LondonMile End RoadLondon E14NSUK The Alan Turing Institute British Library96 Euston RdLondon NW12DBUK Fachbereich Mathematik Universitat HamburgBundesstrasse 5520146 HamburgGermany

The reconstruction of images from their corresponding noisy radon transform is a typical example of an ill-posed linear inverse problem as arising in the application of computerized tomography(CT).As the(naive)solution does not depend on the measured data continuously,regularization is needed to reestablish a continuous *** this work,we investigate simple,but yet still provably convergent approaches to learning linear regularization methods from *** specifically,we analyze two approaches:one generic linear regularization that learns how to manipulate the singular values of the linear operator in an extension of our previous work,and one tailored approach in the Fourier domain that is specific to *** prove that such approaches become convergent regularization methods as well as the fact that the reconstructions they provide are typically much smoother than the training data they were trained ***,we compare the spectral as well as the Fourier-based approaches for CT-reconstruction numerically,discuss their advantages and disadvantages and investigate the effect of discretization errors at differentresolutions.

关键词： Inverse problems regularization Computerized tomography(CT) Machine learning

Post-operative morbidity after neoadjuvant chemotherapy and resection for gallbladder cancer: A national surgical quality improvement program analysis

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World Journal of Gastrointestinal Surgery 2024年第1期16卷 95-102页

作者： Minha Kim Stephanie Stroever Krist Aploks alexander Ostapenko Xiang Da Dong ramanathan Seshadri Department of General Surgery Danbury HospitalDanburyCT 06810United States Department of research and Innovation Nuvance HealthDanburyCT 06810United States Division of Surgical Oncology/Hepato-Pancreato-Biliary Surgery Danbury HospitalDanburyCT 06810United States

BACKGrOUND Gallbladder cancer is the most common malignancy of the biliary ***-adjuvant chemotherapy(NACT)has improved overall survival by enabling r0 ***,there is no consensus of guidelines for neoadjuvant therapy in gallbladder *** investigations continue to analyze the regimen and benefit of NACT for ongoing care of gallbladder cancer patients,we examined American College of Surgeons National Surgical Quality Improvement Program(NSQIP)database to determine if there was higher morbidity among the neo-adjuvant group within the 30-day post-operative *** hypothesized patients who underwent NACT were more likely to have higher post-operative *** To investigate the 30-day post-operative morbidity outcomes between patients who received NACT and underwent surgery and patients who only had *** A retrospective analysis of the targeted hepatectomy NSQIP data between 2015 and 2019 was performed to determine if NACT in gallbladder cancer increased the risk for post-operative morbidity(bile leak,infection rate,rate of converting to open surgery,etc.)compared to the group who only had *** calculate the odds ratio for the primary and secondary outcomes,a crude logistic regression was *** Of the 452 patients,52 patients received NACT prior to *** were no statistically significant differences in the odds of morbidity between the two groups,including bile leak[odds ratio(Or),0.69;95%confidence interval(95%CI):0.16-2.10;P=0.55],superficial wound infection(Or,0.58;95%CI:0.03-3.02;P=0.61),and organ space wound infection(Or,0.63;95%CI:0.18-1.63;P=0.61).CONCLUSION There was no significant difference in the risk of 30-day post-operative morbidity between the NACT and surgery group and the surgery only group.

关键词： Gallbladder cancer Neoadjuvant chemotherapy radical cholecystectomy National Surgery Quality Improvement Program Postoperative outcome

An Automated,Highly Selective reaction Monitoring Instrument Using Molecular rotational resonance Spectroscopy

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Precision Chemistry 2024年第2期2卷 57-62页

作者： Ann Adele Byars Khushi r.Kompally Emily Mechnick reilly E.Sonstrom alexander Mikhonin Justin L.Neill ruth Boetzel James MacGregor Courtney Talicska Jian Li Yizhou Liu BrightSpec Inc.CharlottesvilleVirginia 22903United States Pfizer r&D UK Limited Sandwich CT139NJUnited Kingdom Analytical research and Development Pfizer Research and DevelopmentGrotonConnecticut 06340United States

Online monitoring of chemical reactions by using analytical chemistry tools is a powerful way to maximize control over these *** this paper,we demonstrate the use of molecular rotational resonance,an emerging and extraordinarily selective spectroscopic technique,to perform automated reaction monitoring *** interface using a six-port valve with a calibrated sample loop,coupled to a temperature controlled inlet for analyte volatilization,was developed and *** reactions were chosen for initial characterization:an amine-aldehyde condensation reaction to form an imine product and an isotopic exchange reaction of aβ-ketoester with keto-enol *** spectrometer was able to provide kinetic information about the reaction and determine reaction *** the future,this system can be extended to detect and quantify impurities and characterize reaction selectivity,in addition to the reaction progress.

关键词： molecular rotational resonance spectroscopy reaction monitoring reaction kinetics isotopes process analytical technology