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Towards efficient strain engineering of 2d materials:A four-points bending approach for compressive strain

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Nano Research 2024年第6期17卷 5317-5325页

作者： Hao Li Félix Carrascoso Ana Borrás Gloria P.Moreno Francisco j.Aparicio Ángel Barranco Andrés Castellanos Gómez Campus de Cantoblanco Instituto de Ciencia de Materiales de MadridC.Sor Juana Inés de la Cruz328049 MadridSpain Nanotechnology on Surfaces and Plasma Lab Instituto de Ciencia de Materiales de Sevilla(CSIC-Universidad de Sevilla).C/Americo Vespucio 49E-41092 SevilleSpain departamento de Física Aplicada I Escuela Politécnica SuperiorUniversidad de Sevillac/Virgen deÁfrica 7E-41011 SevilleSpain

Strain engineering,as a powerful strategy to tune the optical and electrical properties of two-dimensional(2d)materials by deforming their crystal lattice,has attracted significant interest in recent years.2d materials can sustain ultra-high strains,even up to 10%,due to the lack of dangling bonds on their surface,making them ideal brittle *** remarkable mechanical resilience,together with a strong strain-tunable band structure,endows 2d materials with a broad optical and electrical response upon ***,strain engineering based on 2d materials is restricted by their nanoscale and strain quantification *** this study,we have modified a homebuilt three-points bending apparatus to transform it into a four-points bending apparatus that allows for the application of both compressive and tensile strains on 2d *** approach allows for the efficient and reproducible construction of a strain system and minimizes the buckling effect caused by the van der Waals interaction by adamantane encapsulation *** results demonstrate the feasibility of introducing compressive strain on 2d materials and the potential for tuning their optical and physical properties through this approach.

关键词： uniaxial compressive strain polymer encapsulation differential reflectance spectroscopy exciton tunability

情报界开源情报战略(2024-2026年)

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情报理论与实践 2024年第9期47卷 F0003-F0003页

作者：吴兆桐(编译) HAINES A d BURNS W j 中国人民大学不详

开源情报(OSINT)是专门针对特定情报优先事项、要求或差距,从公开或商业可得信息中获取的情报。人工智能和机器学习技术的发展为开源情报价值的开发及利用提供了重要机遇,也对开源情报相关风险的规避提出了更高的要求。2024年3月8日,美... 详细信息

开源情报(OSINT)是专门针对特定情报优先事项、要求或差距,从公开或商业可得信息中获取的情报。人工智能和机器学习技术的发展为开源情报价值的开发及利用提供了重要机遇,也对开源情报相关风险的规避提出了更高的要求。2024年3月8日,美国国家情报总监办公室(OdNI)和中央情报局(CIA)联合发布《情报界开源情报战略(2024—2026年)》,旨在通过利用开源情报支持国家安全决策,维护国家安全和国家利益。

关键词：人工智能机器学习技术开源情报中央情报局情报界 OSI 开发及利用优先事项

detailed characterization of kHz-rate laser-driven fusion at a thin liquid sheet with a neutron detection suite

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High Power Laser Science and Engineering 2024年第1期12卷 13-23页

作者： Benjamin M.Knight Connor M.Gautam Colton R.Stoner Bryan V.Egner joseph R.Smith Chris M.Orban juan j.Manfredi Kyle d.Frische Michael L.dexter Enam A.Chowdhury Anil K.Patnaik department of Engineering Physics Air Force Institute of TechnologyWPAFBOHUSA Physics department Marietta CollegeMariettaOHUSA department of Physics The Ohio State UniversityColumbusOHUSA department of Materials Science and Engineering and Department of Electrical and Computer ScienceThe Ohio State UniversityColumbusOHUSA Intense Energy Solutions LLCPlain CityOHUSA

We present detailed characterization of laser-driven fusion and neutron production(-10^(5)/second) using 8 mj, 40 fs laser pulses on a thin(<1 μm) d_2O liquid sheet employing a measurement suite. At relativistic inte... 详细信息

We present detailed characterization of laser-driven fusion and neutron production(-10^(5)/second) using 8 mj, 40 fs laser pulses on a thin(d_2O liquid sheet employing a measurement suite. At relativistic intensity(~ 5 × 10^(18)W/cm^(2))and high repetition rate(1 kHz), the system produces deuterium±deuterium(d-d) fusion, allowing for consistent neutron generation. Evidence of d-d fusion neutron production is verified by a measurement suite with three independent detection systems: an Ej-309 organic scintillator with pulse-shape discrimination, a ~3He proportional counter and a set of 36 bubble detectors. Time-of-flight analysis of the scintillator data shows the energy of the produced neutrons to be consistent with 2.45 MeV. Particle-in-cell simulations using the WarpX code support significant neutron production from d-d fusion events in the laser±target interaction region. This high-repetition-rate laser-driven neutron source could provide a low-cost, on-demand test bed for radiation hardening and imaging applications.

关键词： high-repetition-rate laser-driven fusion laser-plasma interaction liquid target neutron detectors

Adaptive-optical 3d microscopy for microfluidic multiphase flows

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Light(Advanced Manufacturing) 2024年第3期5卷 105-119页

作者： Clemens Bilsing Erik Nützenadel Sebastian Burgmann jürgen Czarske Lars Büttner Laboratory of Measurement and Sensor System Techniques TUD Dresden University of Technology01069 DresdenGermany Chair of Fluid Mechanics Bergische Universitát Wuppertal42119 WuppertalGermany BIOLAS Laboratory of Measurement and Sensor System Techniques01069 DresdenGermany

Measurements based on optical microscopy can be severely impaired if the access exhibits variations of the refractive *** the case of fluctuating liquid-gas boundaries,refraction introduces dynamical aberrations that increase the measurement *** is prevalent at multiphase flows(***,film flows)that occur in many technical applications as for example in coating and cleaning processes and the water management in fuel *** this paper,we present a novel approach based on adaptive optics for correcting the dynamical aberrations in real time and thus reducing the measurement *** shape of the fluctuating water-air interface is sampled with a reflecting light beam(Fresnel Guide Star)and a Hartmann-Shack sensor which makes it possible to correct its influence with a deformable mirror in a closed ***-dimensional flow measurements are achieved by using a double-helix point spread *** measure the flow inside a sessile,oscillating 50-μl droplet on an opaque gas diffusion layer for fuel cells and show that the temporally varying refraction at the droplet surface causes a systematic underestimation of the flow field magnitude corresponding to the first droplet eigenmode which plays a major role in their detachment *** demonstrate that the adaptive optics correction is able to reduce this systematic ***,the adaptive optics system can pave the way to a deeper understanding of water droplet formation and detachment which can help to improve the efficiency of fuels cells.

关键词： double-Helix point spread function Adaptive optics Particle tracking velocimetry Aberration correction depth-resolving microscopy Closed-loop control

Strategy of preparing SmCo based films with high coercivity and remanence ratio achieved by temperature and chemical optimization

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journal of Rare Earths 2024年第7期42卷 1289-1297,I0004页

作者： Yansong Gong Zhaoguo Qiu Sizhe Liang Xinrui Zheng Hongxia Meng Zhigang Zheng deyang Chen Shengfu Yuan Weixing Xia dechang Zeng j.P.Liu School of Materials Science and Engineering South China University of TechnologyGuangzhou510640China Zhongshan R&d Center for Materials Surface and Thin Films Technology of the South China University of Technology Gent Materials Surface Technology(Guangdong)Co.Ltd.Zhongshan528437China Institute for Advanced Materials South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou510006China Yangjiang Branch Guangdong Laboratory Materials Science and Technology Yangjiang Advanced Alloys LaboratoryYangjiang529500China Laboratory of Rare-Earth Magnetic Functional Materials Ningbo Institute of Material Technology and EngineeringChinese Academy of SciencesNingbo315201China department of Physics University of Texas at ArlingtonArlingtonTX76019USA

SmCo based films with excellent intrinsic magnetic properties have promising applications in micro-electro-mechanical system(MEMS).However,due to the complexity of phase composition and uncontrollable crystallization degree of SmCo hard magnetic phase in the film,both the coercivity(Hc)and remanence(Mr)of films are difficult to enhance *** this paper,SmCo based films were deposited with a Cr underlayer and capping layer on single crystal Si substrates via magnetron sputtering *** effects of annealing parameters and Sm/Co atomic ratio on the phase structure and coercivity of films are *** adjusting the Sm/Co atomic ratio from 1:5 to 1:4,Co soft magnetic phase disappears and the single phase SmCo5 is obtained,leading to the increase of coercivity of the films from 30 to 34 *** influence of deposition temperature and Cu doping on magnetic properties of SmCo based films was *** the deposition temperature increases from room temperature to 250℃,the coercivity will further increase from 34 to 51 ***,a severe kink is observed in the demagnetization curves due to the poor exchanged *** analysis of transmission electron microscopy(TEM)confirms that the average size of non-hard magnetic amorphous phase exceeds the effective exchanged coupling length of SmCo5,which contributes to the decoupling and low remanence ***,doping Cu and applying a post-annealing process can significantly improve the crystallization degree of the *** the coercivity and the remanence ratio of the demagnetization curves are greatly *** propose a plausible strategy to prepare the SmCo based films with high coercivity and remanence ratio by temperature and chemical optimization,which can be utilized in high performed MEMS devices.

关键词： Rare earths SmCo based films Phase composition Crystallization conditions Coercivity Remanence ratio

Oxygen tension modulates cell function in an in vitro three-dimensional glioblastoma tumor model

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Bio-design and Manufacturing 2024年第3期7卷 307-319页

作者： Sen Wang Siqi Yao Na Pei Luge Bai Zhiyan Hao dichen Li jiankang He j.Miguel Oliveira Xiaoyan Xue Ling Wang Xinggang Mao State Key Laboratory for Manufacturing System Engineering Xi’an Jiaotong UniversityXi’an 710054China School of Mechanical Engineering Xi’an Jiaotong UniversityXi’an 710054China NMPA Key Laboratory for Research and Evaluation of Additive Manufacturing Medical devices Xi’an Jiaotong UniversityXi’an 710054China 3B’s Research Group I3Bs–Research Institute on BiomaterialsBiodegradables and BiomimeticsUniversity of MinhoHeadquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineAveParkZona Industrial da Gandra4805-017 BarcoGuimarãesPortugal ICVS/3B’s-PT Government Associate Laboratory 4806-909 Braga/Guimar˜aesPortugal department of Pharmacology School of PharmacyFourth Military Medical UniversityXi’an 710032China department of Neurosurgery Xijing HospitalFourth Military Medical UniversityXi’an 710032China

Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor ***,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor *** study reports a three-dimensional(3d)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I *** also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and ***,it compares two-dimensional(2d)and 3d *** comparison purposes,cells cultured in flat culture dishes were used as the control(2d model).Cells cultured in the 3d model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2d ***,the two models yielded significantly different cell ***,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3d *** results indicate that the constructed 3d model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2d culture *** developed 3d glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology.

关键词： Hypoxia Glioma Three-dimensional glioma model In vitro

Effect of age on the standardized ileal amino acid digestibility of soybean meal and canola meal in broilers

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Animal Nutrition 2024年第1期16卷 11-22页

作者： Mukti Barua M.Reza Abdollahi Faegheh Zaefarian Timothy j.Wester Channarayapatna K.Girish Peter V.Chrystal Velmurugu Ravindran Monogastric Research Center School of Agriculture and EnvironmentMassey UniversityPalmerston North 4442New Zealand department of Animal Science and Nutrition Faculty of Veterinary MedicineChattogram Veterinary and Animal Sciences UniversityKhulshiChattogram 4225Bangladesh Nutrition and Care Animal NutritionEvonik(SEA)Pte.Ltd609927 Singapore Complete Feed Solutions Howick 2145AucklandNew Zealand

Standardized ileal digestibility coefficients(SIdC)of nitrogen(N)and amino acids(AA)in two protein sources(soybean meal[SBM]and canola meal[CM])were investigated at six broiler ages(d 7,14,21,28,35,and 42).Two assay diets were formulated to contain either SBM(413 g/kg)or CM(553 g/kg)as the sole dietary AA *** dioxide(5 g/kg)was added as an indigestible marker.A total of 696 male broilers at 1 d old were allotted to 12 replicate cages per age *** assay diet was offered to birds for 4 d prior to the ileal digesta collection on d 7(14 birds/cage),14(12 birds/cage),21(10 birds/cage),28(8 birds/cage),35(8 birds/cage)and 42(6 birds/cage),*** apparent digestibility coefficients were standardized using age-specific basal endogenous AA *** the SBM group,though the SIdC of N tended to be influenced(quadratic;P=0.075)by age,no linear or quadratic response of age effect was observed on the average SIdC of indispensable(IAA)and total AA(TAA).An age effect(quadratic;Pd on the average SIdC of dispensable AA(dAA)in SBM with the highest value recorded at d 7,followed by a decrease from d 14 to 28,which increased beyond d *** SIdC of some individual AA(Arg,Thr,Trp,Cys,Pro)were affected(Pdratic manner by *** the CM,the SIdC of N,average SIdC of IAA,dAA and TAA were influenced(quadratic;PdC of N and average SIdC of dAA and TAA were higher from d 7 to 14,declined at d 21,and then increased beyond d *** average SIdC of IAA was low between d 7 and 28 and increased *** SIdC of individual AA were affected(linear or quadratic;Pdifferent magnitudes by *** age influence on the SIdC AA was variable,depending on the protein source and *** results demonstrate that age-specific SIdC AA data might need consideration in broiler feed formulations.

关键词： Age Amino acid Broiler digestibility Protein source

Highly divergent sympatric lineages of Leptotila verreauxi(Aves:Columbidae)suggest a secondary contact area in the Isthmus of Tehuantepec,Mexico

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Avian Research 2024年第1期15卷 12-21页

作者： Orlando j.Espinosa-Chávez Adolfo G.Navarro-Sigüenza Hernando Rodríguez-Correa Luis A.Sánchez-González Museo de Zoología“Alfonso L.Herrera” Depto.de Biología EvolutivaFacultad de CienciasUniversidad Nacional Autonoma de MexicoApdo.Postal 70-399CP 04510Ciudad de MexicoMexico Posgrado en Ciencias Biologicas Unidad de PosgradoEdificio D1◦PisoCircuito de PosgradosCiudad UniversitariaUniversidad Nacional Autonoma de MexicoCoyoacanCP 04510CDMXMexico Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autonoma de Mexico.Antigua Carretera a Patzcuaro No.8701 Col.Ex Hacienda de San Jose de la HuertaC.P.58190MoreliaMichoacanMexico

due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland *** distributed in the lowlands of the American continent,the White-Tipped dove(Leptotila verreauxi)is a polytypic species with 13 recognized *** of these have been recorded in Mexico,and the distribution of three abuts at the IT,suggesting a contact *** estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt dNA(Nd2 and COI)and one n dNA(β-fibint 7)*** also used correlative ecological niche models(ENM)to assess whether ecological differences across the IT may have acted as a biogeographical *** estimated paleodistributions during the Middle Holocene,Last Glacial Maximum and Last Interglacial,to evaluate the influence of climate changes on the distribution and demographic *** results showed genetically distinct lineages that diverged approximately 2.5 million years *** and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern *** ecological niche comparisons indicated that the ecological niche of sympatric lineages at the IT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low *** results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological ***,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.

关键词： Biogeographical boundary Humid and dry forests Isthmus of Tehuantepec Phylogeography Secondary contact

青藏高原湖泊纹层孢粉记录的过去2000年雨季时长和雨季降水时空变化

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中国科学：地球科学 2024年第3期54卷 808-820页

作者：崔安宁吕厚远侯居峙刘兴起徐德克中国科学院地质与地球物理研究所新生代地质与环境院重点实验室北京100029 中国科学院地球科学研究院北京100029 中国科学院大学地球与行星科学学院北京100049 中国科学院青藏高原研究所环境变化与地表过程重点实验室北京100101 中国科学院大学北京100049 首都师范大学资源环境与旅游学院北京100048

青藏高原雨季时长及雨季降水量的长尺度定量重建,是揭示高原西风、季风时空演变规律及其生态环境效应的关键,其中准确判断高原雨季的起止时间是研究难点.本文通过寻找降水拐点的方法确定了高原不同地点的雨季起、止时间,并计算了雨季时... 详细信息

青藏高原雨季时长及雨季降水量的长尺度定量重建,是揭示高原西风、季风时空演变规律及其生态环境效应的关键,其中准确判断高原雨季的起止时间是研究难点.本文通过寻找降水拐点的方法确定了高原不同地点的雨季起、止时间,并计算了雨季时长和雨季降水量,建立了表土孢粉组合与雨季起止时间、雨季时长和雨季降水量的转换函数,重建了具有年纹层沉积特征的高原北部库赛湖区和中部江错湖区过去2000年来的雨季起止时间、雨季时长和雨季降水量变化.结果表明,过去2000以来,库赛湖区雨季降水序列记录了5次高降水时段:Ad580~680、Ad1000~1100、Ad1200~1450、Ad1550~1780、Ad1920至今,其普遍对应雨季天数长的时段;江错湖区雨季降水序列记录了4次高降水时段:Ad80~500、Ad800~950、Ad1250~1450、Ad1780至今,其与雨季天数长的时段在Ad1000以前对应良好,在Ad1000后关系不明确.在空间上,高原雨季降水呈现出“南北同湿”、“南北同旱”、“南湿北旱”和“南旱北湿”四种模式,其中“南北同湿”可能与异常强盛的夏季风有关,“南北同旱”与弱西风和弱季风有关,“南湿北旱”与强季风和弱西风有关,“南旱北湿”与弱季风和强西风有关.本文从雨季降水的角度揭示了高原2000年来雨季起止时间、雨季时长及雨季降水量的时空演变模式,为进一步认识西风、季风耦合作用提供了自然背景的支持.

关键词：青藏高原过去两千年雨季时长雨季降水量定量重建