检索结果-南通市图书馆

High Power Laser Science and Engineering 2024年第1期12卷 24-29页

作者： Pierre-Marie Dalbies Sandy Cavaro Edouard Bordenave Nathalie Blanchot julien g.Moreau jérôme Neauport CEA CESTA Le BarpFrance

Mid-spatial frequency wavefront deformation can be deleterious for the operation of high-energy laser systems. When fluid cooled high-repetition-rate amplifiers are used, the coolant flow is likely to induce such detrimental mid-spatial frequency wavefront deformations. Here, we describe the design and performance of a 90 mm × 90 mm aperture, liquid-cooled Nd:phosphate split-slab laser amplifier pumped by flash-lamps. The performance of the system is evaluated in terms of wavefront aberration and gain at repetition rates down to 1 shot per minute. The results show that this single cooled split-slab system exhibits low wavefront distortions in the medium to large period range, compatible with a focus on target, and despite the use of liquid coolant traversed by both pump and amplified wavelengths. This makes it a potential candidate for applications in large high-energy laser facilities.

关键词： flash-lamp pumping high-power laser laser cooling neodymium glass wavefront error

Rodent management in Aotearoa New Zealand: approaches and challenges to landscape-scale control

在线全文

学校读者我要写书评

暂无评论

Integrative Zoology 2024年第1期19卷 8-26页

作者： john g.INNES grant NORBURY Araceli SAMANIEgO Susan WALKER Deborah j.WILSON Manaaki Whenua-Landcare Research HamiltonNew Zealand Manaaki Whenua-Landcare Research AlexandraNew Zealand Manaaki Whenua-Landcare Research AucklandNew Zealand Manaaki Whenua-Landcare Research DunedinNew Zealand

Aotearoa—New Zealand has only four rodent species,all *** order of arrival,they are Pacific rat Rattus exulans,brown rat ***,house mouse Mus musculus,and black rat *** management in New Zealand aims mainly to conserve indigenous biodiversity rather than to protect crops or manage diseases,as is usual *** describe four major“regimes”and one major vision for rodent control in New Zealand to meet ecological restoration *** challenges for island eradications are for large islands that are remote or populated by *** 1080 is the only large-scale(tens of thousands of hectares)option for black rat control,but its application requires adjustment to counter subsequent rapid black rat ***“ecosanctuaries”(mean 720 ha)use ground-based traps and poisons to target mainly black rats and face constant *** with mammal-resistant fences(up to 3500 ha)limit reinvasion and target more pest species and have enabled the return of previously extirpated taxa to the main *** Free 2050 aims to eradicate the rat species(but not mice)plus some other introduced mammals from New Zealand by *** vision is not attainable with current tools,but research and experimental management is exploring techniques and *** large scale(to 100000 ha)at which black rats are now targeted for control to extremely low abundance seems to be unique to New Zealand.

关键词： black rat brown rat eradication house mouse rodent control

Malargüe Site Remediation: A Successful Solution for Uranium Mill Tailings

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

原子能科学技术 2024年

作者： BARARI E DíAZ j g gIOMIA KEMPF R A National Atomic Energy Commission Av.Del Libertador 8250 Ciudad Autónoma de Buenos AiresC1429BNP Argentina

Comisión Nacional de Energía Atómica(CNEA) has the responsibility for restoring uranium mining facilities once the operations have finished. CNEA, within its Environmental Program and in compliance with its legal responsibilities, decides to implement a restoration project for all sites related to the mining and processing of uranium ores. The Malargüe Site is located within the Province of Mendoza in the city of Malargüe. It is the first site to successfully complete its remediation. The activities consist of relocation of tailings to an engineering repository. The tailings management(encapsulation) and rehabilitation of the area was finished in june 2017. The remediation alternative for the ore tailings was selected after conducting comparative studies and submitted the project to the society for consideration. The objective of the encapsulation of the mineral tails is to isolate them from the environment, also proceeding with the decontamination and rehabilitation of the area(landscaping,post-closure monitoring and 20 years monitoring period). Encapsulation consisted of the construction of a containment cell for the mine tailings, to isolate them and prevent pollutants from entering the environment through the transfer routes. To clean the impacted areas, the soil was removed, it was incorporated into the encapsulation, and the filling was carried out with natural soils from the *** prevents radon transfer to the environment, as 222Ra is an alpha emitter with a half-life of four days, which produces its own radioactive progeny. Radon progeny are solids, and when a 222Ra nucleus emits an alpha particle into the air, the resulting 218Po nucleus, momentarily electrically charged, adheres to any dust particle. Remediation prevents the discharge into the air containing radon and also containing dust particles charged with intensely radioactive radon progeny. The tasks mentioned make it possible to decrease radon emanation, reduce radiological risks to the

关键词：

The initial stages of Li_(2)O_(2) formation during oxygen reduction reaction in Li-O_(2) batteries:The significance of Li_(2)O_(2) in charge-transfer reactions within devices

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2024年第1期88卷 223-231,I0006页

作者： Daniela M.josepetti Bianca P.Sousa Simone A.j.Rodrigues Renato g.Freitas gustavo Doubek Advanced Energy Storage Division LABCenter for Innovation on New EnergiesSchool of Chemical EngineeringUniversity of CampinasAv Albert Einstein 50013083-852CampinasSPBrazil Institute of Physics&Department of Chemistry Laboratory of Computational MaterialsFederal University of Mato Grosso78060-900CuiabáMTBrazil

Lithium-oxygen batteries are a promising technology because they can greatly surpass the energy density of lithium-ion ***,this theoretical characteristic has not yet been converted into a real device with high *** with air contamination,metallic lithium reactivity,and complex discharge and charge reactions are the main issues for this technology.A fast and reversible oxygen reduction reaction(ORR)is crucial for good performance of secondary batteries',but the partial knowledge of its mechanisms,especially when devices are concerned,hinders further *** this perspective,the present work uses operando Raman experiments and electrochemical impedance spectroscopy(EIS)to assess the first stages of the discharge processes in porous carbon electrodes,following their changes cycle by cycle at initial operation.A growth kinetic formation of the discharge product signal(Li_(2)O_(2))was observed with operando Raman,indicating a first-order reaction and enabling an analysis by a microkinetic *** solution mechanism in the evaluated system was ascribed for an equivalent circuit with three time *** the time constant for the anode interface reveals to remain relatively constant after the first discharge,its surface seemed to be more *** model indicated that the reaction occurs at the Li_(2)O_(2) surface,decreasing the associated resistance during the initial discharge ***,the growth of Li_(2)O_(2) forms a hetero-phase between Li_(2)O_(2)/electrolyte,while creating a more compact and homogeneous on the Li_(2)O_(2)/cathode *** methodology here described thus offers a way of directly probing changes in surface chemistry evolution during cycling from a device through EIS analysis.

关键词： Li-O_(2)battery Operando Raman analysis Equivalent circuit modeling Time-constant distribution

Challenges and opportunities in the production of magnesium parts by directed energy deposition processes

在线全文

学校读者我要写书评

暂无评论

journal of Magnesium and Alloys 2024年第5期12卷 1663-1686页

作者： gürel Cam Ali günen Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Mechanical Engineering31200 Iskenderun-HatayTurkey Iskenderun Technical University Faculty of Engineering and Natural SciencesDepartment of Metallurgy and Materials Engineering31200 Iskenderun-HatayTurkey

Mg-alloys have gained considerable attention in recent years for their outstanding properties such as lightweight,high specific strength,and corrosion resistance,making them attractive for applications in medical,aerospace,automotive,and other transport ***,their widespread application is hindered by their low formability at room temperature due to limited slip *** Mg-alloys have low mechanical properties due to the presence of casting defects such as porosity and anisotropy in addition to the high *** casting methods benefit from established process optimization techniques for these problems,additive manufacturing methods are increasingly replacing casting methods in Mg alloys as they provide more precise control over the microstructure and allow specific grain orientations,potentially enabling easier optimization of anisotropy properties in certain *** metal additive manufacturing(MAM)technology also results in some manufacturing defects such as inhomogeneous microstructural evolution and porosity and additively manufactured Mg alloy parts exhibit lower properties than the wrought parts,they in general exhibit superior properties than the cast ***,MAM is a promising technique to produce Mg alloy *** energy deposition processes,particularly wire arc directed energy deposition(WA-DED),have emerged as an advantageous additive manufacturing(AM)technique for metallic materials including magnesium alloys,offering advantages such as high deposition rates,improved material efficiency,and reduced production costs compared to subtractive ***,the inherent challenges associated with magnesium,such as its high reactivity and susceptibility to oxidation,pose unique hurdles in the application of this *** review paper delves into the progress made in the application of DED technology to Mg-alloys,its challenges,and ***,the predominant imperfections,notably inhomo

关键词： Additive manufacturing DED processes Arc-DED Wire arc additive manufacturing(WAAM) 3-D printing High deposition rate

Exploring the associations between skeletal muscle echogenicity and physical function in aging adults:A systematic review with meta-analyses

在线全文

学校读者我要写书评

暂无评论

journal of Sport and Health Science 2024年第6期13卷 820-840页

作者： Dustin j.Oranchuk Stephan g.Bodkin Katie L.Boncella Michael O.Harris-Love Muscle Morphology Mechanicsand Performance LaboratoryDepartment of Physical Medicine and RehabilitationUniversity of Colorado Anschutz Medical CampusAuroraCO 80045USA Department of Physical Therapy

Background:Assessment and quantification of skeletal muscle within the aging population is vital for diagnosis,treatment,and injury/disease *** clinical availability of assessing muscle quality through diagnostic ultrasound presents an opportunity to be utilized as a screening tool for function-limiting ***,relationships between muscle echogenicity and clinical functional assessments require authoritative ***,we aimed to(a) synthesize the literature to assess the relationships between skeletal muscle echogenicity and physical function in older adults(≥60 years),(b) perform pooled analyses of relationships between skeletal muscle echogenicity and physical function,and(c) perform sub-analyses to determine between-muscle ***:CINAHL,Embase,MEDLINE,PubMed,and Web of Science databases were systematically searched to identify articles relating skeletal muscle echogenicity to physical function in older ***-of-bias assessments were conducted along with funnel plot ***-analyses with and without sub-analyses for individual muscles were performed utilizing Fisher's Z transformation for the most common measures of physical ***'s Z was back-transformed to Pearson's r for ***:Fifty-one articles(n=5095,female=~2759,male=~2301,72.5± 5.8 years,mean±SD(1 study did not provide sex descriptors))were extracted for review,with previously unpublished data obtained from the authors of 13 *** rectus femoris(n=34) and isometric knee extension strength(n=22) were the most accessed muscle and physical qualities,*** relationship between quadriceps echogenicity and knee extensor strength was moderate(n=2924,r=-0.36(95% confidence interval:-0.38 to-0.32),p grip strength,walking speed,sit-to-stand,timed up-and-go) resulting in slightly weaker correlations(r:-0.34 to-0.23,all p <0.001).Sub-analyses determined minimal differences in predicti

关键词： Correlations Echo intensity Elderly Intramuscular fat Strength

Recent research in mechanical properties of geopolymer-based ultrahigh-performance concrete:A review

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第2期32卷 67-88页

作者： g.Murali Division of Research&Innovation Uttaranchal UniversityDehradun 248007India

Due to the growing need for sustainable and ultra-high-strength construction materials,scientists have created an innovative ultra-high-performance concrete called geopolymer based ultra-highperformance concrete(gUHPC).Besides,in the last few decades,there have been a lot of explosions and ballistic attacks around the world,which have killed many civilians and fighters in border *** this context,this article reviews the fresh state and mechanical properties of ***,the ingredients of gUHPC and fresh properties such as setting time and flowability are briefly ***,the review of compressive strength,flexure strength,tensile strength and modulus of elasticity of fibrous ***,the blast and projectile impact resistance performance was ***,the microstructural characteristics were reviewed using the scanning electron microscope and X-ray Powder *** review outcome reveals that the mechanical properties were increased when 30%silica fume was added to a higher dose of steel fibre to improve the microstructure of *** is hypothesized that the brittleness of gUHPC was mitigated by adding 1.5%steel fibre reinforcement,which played a role in the decrease of contact explosion cratering and *** the need for cement in gUHPC was a key factor in the review,indicating a promising potential for lowering carbon ***,gUHPC research is still in its early stages,so more study is required before its full potential can be utilized.

关键词： Mechanical properties Blast Projectile impact Fibre geopolymer Silica fume Alkaline activators

Stubborn Hypoxia in Neonates with D-Transposition of the great Arteries after Arterial Switch Operation: Central Sleep Apnea as the Cause and Potential Indicator of Brain Immaturity

在线全文

学校读者我要写书评

暂无评论

Congenital Heart Disease 2024年第2期19卷 185-195页

作者： Camden L.Hebson Kyle Bliton Amr Y.Hammouda Kaitlyn Barr W.Hampton gray Mohini gunnett Waldemar F.Carlo Department of Pediatrics Division of Pediatric CardiologyUniversity of Alabama BirminghamBirmingham35233USA Department of Pediatrics Division of Pediatric PulmonologyUniversity of Alabama BirminghamBirmingham35233USA Department of Pediatrics University of Alabama BirminghamBirmingham35233USA Department of Surgery Division of Cardiothoracic SurgeryUniversity of Alabama BirminghamBirmingham35233USA

D-transposition of the great arteries(d-TgA)is surgically repaired with the arterial switch operation(ASO)with excellent results,however short and long-term morbidities still develop including neurocognitive *** significant central sleep apnea is uncommon in non-premature infants,but when present indicates immature autonomic control of respiration likely due to a neurologic *** report the unanticipatedfinding of central sleep apnea in four-term neonates with d-TgA after uncomplicated ASO,with the short-term complication of delayed hospital discharge and long-term concerns regarding this early marker of brain immaturity and its hindrance to normal *** this report,we will review each patient’s clinical course and then examine the literature on pediatric central sleep apnea,neurodevelopmental outcomes after ASO,and the important overlap of these entities in the care of patients going forward.

关键词： Transposition congenital heart disease sleep apnea polysomnography

Interfacial stress engineering toward enhancement of ferroelectricity in Al doped HfO_(2)thin films

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen M M Chen Y Liu D W Cao g j Chen Department of Microelectronics Jiangsu UniversityZhenjiang 212013China Department of Physics Jiangsu UniversityZhenjiang 212013China guangdong–Hong Kong–Macao joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted much attention owing to its superior ferroelectricity at an ultra-thin thickness and good compatibility with Si-based complementary metal-oxide-semiconductor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermodynamically modulated via interfacial stress *** this paper,the growth of improved ferroelectric Al doped HfO_(2)(HfO_(2):Al)thin films on(111)-oriented Si substrate has been *** analysis has suggested that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented Si substrate suffered from a strong compressive strain,which promoted the crystallization of(111)-oriented o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** addition,the in-plane lattice of(111)-oriented Si substrate matches well with that of(111)-oriented o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accordingly,an improved ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provide a simple way toward the preparation of improved ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)

High CO_(2)permeation using a new Ce_(0.85)gd_(0.15)O_(2-δ)-LaNiO_(3)composite ceramic–carbonate dual-phase membrane

在线全文

学校读者我要写书评

暂无评论

journal of Environmental Sciences 2024年第6期140卷 219-229页

作者： Daniela gonzález-Varela jFrancisco gómez-garcía gustavo Tavizon Heriberto Pfeiffer Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de MéxicoCd.UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMéxico Departamento de Física y Química Teórica Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCd.UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMéxico 不详

This work shows the synthesis,characterization and evaluation of dense-ceramic membranes made of Ce_(0.85)gd_(0.15)O_(2-δ)-LaNiO_(3)(Cg-LN)composites,where the fluorite-perovskite ratio(Cg:LN)was varied as follows:75:25,80:20 and 85:15 wt.%.Supports were initially characterized by XRD,SEM and electrical conductivity(using vacuum and oxygen atmospheres),to determine the composition,microstructural and ionic-electronic conductivity ***,supports were infiltrated with an eutectic carbonates mixture,producing the corresponding dense dual-phase membranes,in which CO_(2)permeation tests were ***,CO_(2)permeation experiments were performed from 900 to 700℃,in the presence and absence of oxygen(flowed in the sweep membrane side).Results showed that these composites possess high CO_(2)permeation properties,where the O_(2)addition significantly improves the ionic conduction on the sweep membrane ***,the gC80-LN20 composition presented the best results due to the following physicochemical characteristics:high electronic and ionic conductivity,appropriate porosity,interconnected porous channels,as well as thermal and chemical stabilities between the composite support and carbonate phases.

关键词： CO_(2)permeation Doped CeO_(2) LaNiO_(3) Impedance Ceramic carbonate membrane