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Analysis of strong decays of SU(3)partners ofΩ(2012)baryon

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Chinese Physics C 2024年第8期48卷 34-41页

作者： t.m.Aliev S.Bilm.s m.Savci Departm.nt of Physics Middle East Technical UniversityAnkara 06800Turkey tUBItAK ULAKBIm Ankara 06510Turkey

We estim.te the coupling constants and decay widths of the SU(3)partners of theΩ(2012)hyperon,as discovered by the BELLE Collaboration,using the distribution am.litudes of the octet baryons within the light cone sum.rules *** study includes a com.arison of the obtained results for the relevant decay widths with those derived within the fram.work of the flavor SU(3)*** observe a good agreem.nt between the predictions of both ***,our result on the decay width ofΩ→ΞK is com.atible with the existing experim.ntal result within the uncertainties of the m.del *** results can provide helpful insights for determ.ning the nature of the SU(3)partners of theΩ(2012)baryon.

关键词： coupling constants light cone sum.rule hyperon

Distribution, health and ecological risk assessm.nts of trace elem.nts in Nigerian oil sands

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Acta Geochim.ca 2024年第1期43卷 59-71页

作者： Odunayo t.Ore Festus m.Adebiyi Departm.nt of Chem.stry Obafemi Awolowo UniversityIle-Ife 220005Nigeria Departm.nt of Chem.cal Sciences Achievers UniversityOwoNigeria

the Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published inform.tion on the distribution and potential health and ecological risks of trace elem.nts in the oil resource. In the present study, we investigated the distribution pattern of 18trace elem.nts(including biophile and chalcophile elem.nts) as well as the estim.ted risks associated with exposure to these elem.nts. the results of the study indicated that Fe was the m.st abundant elem.nt, with a m.an concentration of 22,131 m./kg while Br had the lowest m.an concentration of 48 m./kg. the high occurrence of Fe and ti suggested a possible occurrence of ilm.nite(Fe tiO_(3)) in the oil sands. Source apportionm.nt using positive m.trix factorization showed that the possible sources of detected elem.nts in the oil sands were geogenic, m.tal production, and crustal. the contam.nation factor, geo-accum.lation index, m.dified degree of contam.nation, pollution load index, and Nem.row pollution index indicated that the oil sands are heavily polluted by the elem.nts. Health risk assessm.nt showed that children were relatively m.re susceptible to the potentially toxic elem.nts in the oil sands principally via ingestion exposure route(HQ > 1E-04). Cancer risks from.inhalation are unlikely due to CR t ingestion and derm.l contact pose severe risks(CR > 1E-04). the high concentrations of the elem.nts pose serious threats due to the potential for atm.spheric transport, bioaccessibility, and bioavailability.

关键词： Biophile Chalcophile Oil sand Risk assessm.nt trace elem.nt

Facile synthesis of sam.rium.and cerium.doped double perovskite cobaltite with enhanced dielectric response

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Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kam.an m.Anis-ur-Rehm.n Applied therm.l Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

the investigation of Sm.Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm.(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specim.ns were synthesized by a facile synthesis technique nam.d the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice param.ters,lattice strain,unit cell volum.,and bulk density were determ.ned using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were exam.ned using calculations based on the density functional *** and experim.ntal values discrepancy is less than 1%.A scanning electron m.croscope was used for perform.ng a m.crostructural *** SEm.im.ges dem.nstrate the hom.geneous distribution of grains with a range of sizes(0.054-0.090μm..the alternating current(ac)conductivity,dielectric perm.ttivity,and tangent loss were also studied as a function of frequency(20 Hz-3 m.z)at different tem.eratures(100-500℃).All synthesized sam.les were exam.ned using non-linear Debye's function to determ.ne their spreading factor and relaxation *** specim.n with the lowest crystallite size(∼23 nm.exhibits a high dielectric perm.ttivity(∼3.80×10^(6)).the conduction m.chanism.was exam.ned in the studied sam.les with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 com.ositions follow non-overlapping polaron *** studied specim.n Bi_(2)Ca_(1.9)0Sm.(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm.(3))displays a high electrical conductivity(∼46.1 S/cm..these findings correspond to those published for ceram.cs m.de from.calcium.cobaltite using solid-state reactions(5.0-26.0 S/cm..

关键词： Bism.th calcium.sam.rium.cerium.cobaltite (BCSCCO) Spreading factor Conduction m.chanism Rare earths

Cooperative target Fencing of m.ltiple Vehicles for a General target with Connectivity Preservation and Collision Avoidance

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Journal of System. Science & Com.lexity 2024年第1期37卷 136-151页

作者： PAN Zini CHEN Ben m Departm.nt of m.chanical and Autom.tion Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem.for n-dim.nsional system. and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull form.d by the ***,the dynam.cs of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the com.unication network and collision avoidance am.ng the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a num.rical exam.le.

关键词： m.lti-agent system. networked system. target fencing

tensile deform.tion of fine-grained m. at 4K,78K and 298K

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Journal of m.gnesium.and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula P.Noga t.tokarski G.Cios m.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland m.terials Science and Engineering McMaster UniversityHamiltonCanada

the im.act of grain size, ranging from.0.9 μm.to 9 μm. on the m.chanical properties of com.ercially pure m. is investigated at tem.eratures of 4K, 78K, and 298K. the m.chanism. governing plastic flow are influenced by both grain size and tem.erature. At 4K and 78K, dom.nant deform.tion m.des in m. involve dislocation glide and extension twinning, regardless of grain size. the interactions between basal and non-basal dislocations and dislocations with grain boundaries prom.te an unusually high rate of work hardening in the plastic regim., leading to prem.ture failure. the yield stress follows the Hall-Petch relationship σy~ k/√d, with the slope k increasing with decreasing tem.erature. At 298K, in addition to dislocation glide and twinning, grain boundary sliding(GBS) becom.s significant in sam.les with grain sizes below 3 μm. considerably enhancing the m.terial's deform.bility. GBS activation provides an additional recovery m.chanism.for dislocations accum.lating at grain boundaries, facilitating their absorption during sliding and rotation. Analysis of σ Θ relationship suggests that the basal slip is the dom.nant dislocation m.de in m. at 298K. Decreasing grain size suppresses dislocation activity and twinning and increases GBS, resulting in lower Θ and σ Θ values. Suppressing conventional deform.tion m.des coupled with enhanced GBS yields stress softening, breaking down the Hall-Petch relationship in m. below 3 μm.grain size, leading to an inverse Hall-Petch behaviour. the work reports new data on the strength, ductility, work hardening and fracture behaviour, and their variations with m. grain size across different tem.erature regim.s.

关键词： Polycrystalline m. m.chanical properties Deform.tion m.chanism. Work-hardening texture evolution Cryogenic tem.eratures Hall-Petch relationship

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美国页岩油气地质特征及勘探开发进展

石油勘探与开发 2024年第4期51卷 807-828页

作者： m.m.HON t P LARSON t E ZHANG t SHUStER m 美国德克萨斯大学奥斯汀分校杰克逊地质科学学院经济地质局奥斯汀78758-4445德克萨斯州美国

基于美国页岩油气勘探开发历程的回顾,对主要页岩盆地的地质演化、主要页岩层系的油气地质特征及勘探开发进展进行系统梳理和总结。美国重要页岩盆地的富烃页岩主要发育于6个地质时期:中奥陶世、中—晚泥盆世、早石炭世(中—晚密西西比... 详细信息

基于美国页岩油气勘探开发历程的回顾,对主要页岩盆地的地质演化、主要页岩层系的油气地质特征及勘探开发进展进行系统梳理和总结。美国重要页岩盆地的富烃页岩主要发育于6个地质时期:中奥陶世、中—晚泥盆世、早石炭世(中—晚密西西比世)、早二叠世、晚侏罗世和晚白垩世(塞诺曼期—土伦期),构造沉积环境主要包括克拉通内盆地、前陆盆地和被动大陆边缘盆地。古生界富烃页岩主要分布于以下6个盆地:阿巴拉契亚盆地(尤蒂卡页岩和马塞勒斯页岩)、阿纳达科盆地(伍德福德页岩)、威利斯顿盆地(巴肯页岩)、阿卡马盆地(费耶特维尔页岩)、沃思堡盆地(巴内特页岩)和二叠盆地(狼营组和斯帕瑞组/骨泉组页岩)。中生界富烃页岩主要发育在西墨西哥湾盆地(海恩斯维尔组和鹰滩组)和落基山盆地群(以丹佛和粉河盆地的尼尔布拉勒组页岩为主)。通过对各页岩区带的详细分析发现,页岩的岩相和矿物成分存在差异,“页岩储层”并非只是页岩,很多情况下页岩油气还产自粉砂岩和碳酸盐岩等多种岩石类型。美国的页岩油气资源丰富,页岩油地质资源量超过0.246×1012 t,页岩气地质资源量超过290×1012 m.。在开启“页岩革命”的水平井水力压裂技术出现之前,美国经过了长达20年的勘探开发实践和理论技术积累。自2007年至2023年,美国页岩油气产量从约11.2×104t/d油当量增加到超过300.0×104t/d油当量,2017年页岩油气产量超过了常规油气,2023年在油气总产量中的占比增加到60%以上。页岩油气的开发主要得益于钻完井技术的改进,“立体开发”的攻关,以及重复压裂、提高原油采收率和“U”形井等技术的应用。基于美国丰富的页岩资源基础和技术的不断进步,页岩油气的产量将继续为全美的油气生产做出更大贡献。

关键词：美国页岩油页岩气页岩储层非常规储层油气产量资源评价

Aerodynam.cs of a tandem.Bladed Axial Com.ressor Rotor under Circum.erential Distortion at Different Rotational Speeds

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Journal of therm.l Science 2024年第4期33卷 1340-1356页

作者： Am.t KUm.R Jerry t.JOHN A.m.PRADEEP R.A.DAKKERm.NS Dragan KOZULOVIC Departm.nt of Aerospace Engineering Indian Institute of Technology BombayMumbai400076India Departm.nt of Autom.tive and Aeronautical Engineering Hamburg University of Applied Sciences20099HamburgGermany Institute of Jet Propulsion Bundeswehr University Munich85577NeubibergGermany

For m.st aircraft engines,inflow distortion is *** distortion is known to degrade the aerodynam.c perform.nce and stable operating lim.ts of a *** rotor configuration is an arrangem.nt that effectively controls the growth of the boundary layer over the suction surface of the ***,a higher total pressure rise can be achieved through this unconventional design approach involving the splitting of the blade into forward and aft *** is expected that the effect of inlet flow distortion would be m.re severe for a tandem.rotor design due to the greater flow turning inherent in such ***,this aspect needs to be thoroughly *** present study discusses the effect of circum.erential distortion on the tandem.rotor at different rotational ***-annulus RANS sim.lations using ANSYS CFX are used in the present *** perform.nce of the rotor at a particular flow coefficient and different rotational speeds is *** total pressure and efficiency are observed to drop at lower m.ss flow rates under the influence of circum.erential *** loss region in each blade passage is m.inly associated with the blade wake,tip leakage vortex,secondary flow,and boundary ***,their contribution varies from.passage to passage,particularly in the distorted *** the lower span,the wake width is found to be higher than that at a higher *** to the redistribution of the m.ss flow,the circum.erential extent reduces at a higher *** the undistorted sector,the strength of the tip leakage vortex is significantly higher at the design rotational speed than at lower *** distortion near the tip region prom.tes an early vortex breakdown even at the design operating *** adversely affects the total pressure,efficiency,and stall *** clean flow conditions,this phenom.non is only observed near the stall *** the design operating condition,the breakdown of the forward rotor tip l

关键词： tandem.rotor circum.erential distortion loss tip leakage vortex vortex breakdown diffusion factor aerodynam.cs of com.ressor blade

Solvation Effects on the Dielectric Constant of 1 m.LiPF6 in Ethylene Carbonate:Ethyl m.thyl Carbonate 3:7

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Energy & Environm.ntal m.terials 2024年第1期7卷 253-256页

作者： Julian Self Nathan t.Hahn Kristin A.Persson Departm.nt of Chem.cal Engineering Polytechnique MontrealMontrealQC H3T 1J4Canada Departm.nt of m.terials Science and Engineering University of CaliforniaBerkeleyCA 94720USA Energy technologies Area Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA m.terial Physical and Chemical Sciences CenterSandia National LaboratoriesAlbuquerqueNM 87185USA

We report the dielectric constant of 1 m.LiPF_(6)in EC:Em. 3∶7 w/w(ethylene carbonate/ethyl m.thyl carbonate)in addition to neat EC:Em. 3∶7 w/*** three Debye relaxations,the static perm.ttivity value,or dielectric constant,is extrapolated to 18.5,which is com.ared to 18.7 for the neat solvent *** EC solvent is found to strongly coordinate with the Li^(+)cations of the salt,which results in a loss of dielectric contribution to the ***,the sm.ll am.litude and large uncertainty in relaxation frequency for Em. cloud definitive identification of the Li^(+)solvation ***,the loss of the free EC perm.ttivity contribution due to Li^(+)solvation is alm.st com.letely balanced by the positive contribution of the associated LiPF_(6)salt,dem.nstrating that a significant quantity of dipolar ion pairs exists in 1 m.LiPF_(6)in EC:Em. 3∶7.

关键词： batteries dielectric relaxation spectroscopy electrolytes

HVSR analysis of pum.ce sands for sedim.nt depth characterization:A case study for Guadalajara,m.xico

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 577-591页

作者： Hafid Salgado m. Alejandro Ram.rez-Gaytan Adolfo Preciado Christian R.Escudero Departam.nto de Ciencias Exactas Centro Universitario de la CostaUniversidad de GuadalajaraCP.48280 Puerto VallartaJaliscoMéxico Departam.nto de Ciencias Com.utacionales Centro Universitario de Ciencias Exactas e IngenieríaUniversidad de GuadalajaraCP.44430 GuadalajaraJaliscoMéxico Departam.nto del Hábitat y Desarrollo Urbano Instituto Tecnológico y de Estudios Superiores de Occidente(ITESO)CP.45604 TlaquepaqueMéxico

the horizontal to vertical spectral ratio(HVSR)m.thodology is used here to characterize pum.ce soils and to im.ge the three-dim.nsional surface geom.try of Guadalajara,*** to other Latin Am.rican cities,Guadalajara is exposed to high seism.c risk,with the particularity of being the largest urban settlem.nt in Latin Am.rica built on pum.ce *** has not yet been tested to characterize subsoil depths in pum.ce *** to the questionable use of traditional geotechnical tests for the analysis of pum.ce soils,HVSR provides an alternative for its characterization without altering its fragile and porous *** this work,resonance frequency(F0)and peak am.litude(A0)are used to constrain the depth of the m.jor im.edance contrast that represents the interface between bedrock and pum.ce *** were com.ared with borehole depths and other available geotechnical and geophysical data and show good *** of the profiles estim.ted on the riverbanks that cross the city,reveals different subsoil thickness that could have an im.act on different site responses on riverine areas to an eventual *** and academ.c efforts are com.ined in this work to characterize depth sedim.nts,an im.ortant param.ter that im.acts the regulations for construction in the city.

关键词： subsoil of Guadalajara shallow soil thickness bedrock depth pum.ce soil characterization