检索结果-南通市图书馆

BaTiO_(3)solid solutions co-doped with gd^(3+)and Eu^(3+):Synthesis,structural evolution and dielectric properties

Journal of Rare Earths 2024年第10期42卷 1920-1926页

作者： R.martínez-López m.Pérez-Labra J.A.Romero-Serrano F.R.Barrientos-Hernández m.Reyes-Pérez m.I.Valenzuela-Carrillo g.Urbano-Reyes V.E.Reyes-Cruz g.I.Dávila-Pulido Academic Area of Earth Sciences and materials Autonomous University of Hidalgo StateRoad Pachuca-Tulancingo Km 4.5 Mineral de La Reforma.Hidalgo42184Mexico metallurgy and materials Department ESIQIE-IPNUPALMZacatencoCiudad de Mexico07738Mexico Autonomous University of Coahuila Boulevard Adolfo López Mateos S/nNueva RositaCoahuila26800Mexico

In this paper,the synthesis,structural evolution,and dielectric properties of BaTiO_(3)solid solutions codoped with rare earth elements(gd^(3+)and Eu^(3+))prepared using the solid-state reaction method are *** pure precursor powders of BaCl_3,TiO_(2),gd_(2)O_(3),and Eu_(2)O_(3)were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 mPa and sintered at 1300℃in air atmosphere for 6 h to obtain Ba_(1-3x)gd_(2x)Ti_(1-3x)Eu_(4x)O_(3)(x=0,0.0015,0.01 and0.1).X-ray diffraction(XRD)and Rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO_(3)for the samples with x=0,0.0015 and 0.01,as well as a consistent increment in the lattice parameters caused by the *** solubility limit of gd^(3+)and Eu^(3+)in the BaTiO_(3)structure is reached for the sample with x>0.01,and the orthorhombic Eu_2TiO_(5)and monoclinic BaTi_(2)O_(5)secondary phases were *** Raman results show the characteristic peaks of ferroelectric tetragonal BaTiO_(3)around 716 cm^(-1)(LO of A1 symmetry),515 cm^(-1)(TO of A1 symmetry),and 305 cm^(-1)(B1).The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,gd,and Eu homogeneously distributed in the BaTiO_(3)*** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO_(3) Doping gadolinium Europium Synthesis Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhancing production monitoring: A back allocation methodology to estimate well flow rates and assist well test scheduling

引用

PETROLEUm RESEARCH 2024年第3期9卷 369-379页

作者： Chaves, g. S. Ferreira Filho, V. J. m. Univ Fed Rio De Janeiro Rio De Janeiro Brazil

Production flow rates are crucial to make operational decisions, monitor, manage, and optimize oil and gas fields. Flow rates also have a financial importance to correctly allocate production to fiscal purposes required by regulatory agencies or to allocate production in fields owned by multiple operators. Despite its significance, usually only the total field production is measured in real time, which requires an alternative way to estimate wells' production. To address these challenges, this work presents a back allocation methodology that leverages real-time instrumentation, simulations, algorithms, and mathematical programming modeling to enhance well monitoring and assist in well test scheduling. The methodology comprises four modules: simulation, classification, error calculation, and optimization. These modules work together to characterize the flowline, wellbore, and reservoir, verify simulation outputs, minimize errors, and calculate flow rates while honoring the total platform flow rate. The well status generated through the classification module provides valuable information about the current condition of each well (i.e. if the well is deviating from the latest well test parameters), aiding in decision-making for well testing scheduling and prioritizing. The effectiveness of the methodology is demonstrated through its application to a representative offshore oil field with 14 producing wells and two years of daily production data. The results highlight the robustness of the methodology in properly classifying the wells and obtaining flow rates that honor the total platform flow rate. Furthermore, the methodology supports well test scheduling and provides reliable indicators for well conditions. By utilizing real-time data and advanced modeling techniques, this methodology enhances production monitoring and facilitates informed operational decision-making in the oil and gas industry. (c) 2024 The Authors. Publishing services provided by Elsevier B.V. on be

关键词： Production estimation Real-time production Production monitoring Back allocation Well test scheduling Flow rate estimation 2-PHASE FLOW

来源：

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

Photometric Studies of EV Cnc and AH Cnc in the Open Cluster m67

引用

Research in Astronomy and Astrophysics 2024年第8期24卷 196-211页

作者： mamatha Rani g. K.Sriram Deblina Lahiri Vijaya,A. Department of Astronomy Osmania UniversityHyderabad 500007India

Contact binaries at various stages of evolution unveil various operating mechanisms that drive *** report the photometric and period variation analysis of two contact binaries EV Cnc and AH Cnc in open cluster *** observed the cluster from the JCBT 1.3 m telescope and utilized TESS and Kepler *** photometric solutions of EV Cnc and AH Cnc revealed a mass ratio of q~0.41 and~0.15 with an inclination of i=42°and87°*** solutions suggest that EV Cnc is probably a semi-detached and AH Cnc is a deep low-mass ratio contact *** study of O-C variation analysis indicates that for both systems,the period is increasing which suggests the mass transfer is occurring from secondary to *** the case of AH Cnc and based on simulations by randomly varying the time of minima to fit the LITE solution,we noted the third body orbital period to be around P_(3)=26.82±2.54 yr,which is different from earlier reported values and conclude that future observations are required to confirm this *** compare these two systems with other similar contact binaries to get an estimate of the final configuration of the respective systems.

关键词： (stars)binaries(including multiple) close-(stars)binaries eclipsing-stars activity

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Development of an ultrathin liquid sheet target for laser ion acceleration at high repetition rates in the kilohertz range

引用

High Power Laser Science and Engineering 2024年第3期12卷 134-145页

作者： m.Füle A.P.Kovács T.gilinger m.Karnok P.gaál S.Figul g.marowsky K.Osvay National Laser-Initiated Transmutation Laboratory University of SzegedSzegedHungary Department of Experimental Physics University of SzegedSzegedHungary ELI ALPS ELI-HU Non-Profit Ltd.SzegedHungary Department of Optics and Quantum Electronics University of SzegedSzegedHungary Advanced microfluidic Systems gmbH GöttingenGermany

A colliding microjet liquid sheet target system was developed and tested for pairs of round nozzles of 10,11 and 18μm in *** sheet's position stability was found to be better than a few *** interaction with 50 mJ laser pulses,the 18μm jet has a resonance amplitude of 16μm at a repetition rate of 33 Hz,while towards 100 Hz it converges to 10μm for all nozzles.A white-light interferometric system was developed to measure the liquid sheet thickness in the target chamber both in air and in vacuum,with a measurement range of 182 nm±1μm and an accuracy of±3%.The overall shape and 3D shape of the sheet follow the Hasson±Peck model in *** vacuum versus air,the sheet gradually loses 10%of its thickness,so the thinnest sheet achieved was below 200 nm at a vacuum level of 10±4mbar,and remained stable for several hours of operation.

关键词： diagnostics laser ion acceleration nanometric liquid sheet targets vacuum test

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Highly-sensitive wafer-scale transfer-free graphene mEmS condenser microphones

引用

microsystems & Nanoengineering 2024年第1期10卷 267-275页

作者： Roberto Pezone Sebastian Anzinger gabriele Baglioni Hutomo Suryo Wasisto Pasqualina m.Sarro Peter g.Steeneken Sten Vollebregt Laboratory of Electronic Components Technology and Materials(ECTM)Department of MicroelectronicsDelft University of TechnologyDelftThe Netherlands Infineon Technologies Ag Am Campeon 1-15Neubiberg 85579Germany Kavli Institue of Nanoscience Department of Quantum NanoscienceDelft University of TechnologyDelftthe Netherlands Department of Precision and microsystems Engineering(PmE) Delft University of TechnologyDelftThe Netherlands

Since the performance of micro-electro-mechanical system(mEmS)-based microphones is approaching fundamental physical,design,and material limits,it has become challenging to improve *** works have demonstrated graphene’s suitability as a microphone *** potential for achieving smaller,more sensitive,and scalable onchip mEmS microphones is yet to be *** address large graphene sizes,graphene-polymer heterostructures have been proposed,but they compromise performance due to added polymer mass and *** work demonstrates the first wafer-scale integrated mEmS condenser microphones with diameters of 2R=220-320μm,thickness of 7 nm multi-layer graphene,that is suspended over a back-plate with a residual gap of 5μ*** microphones are manufactured with mEmS compatible wafer-scale technologies without any transfer steps or polymer layers that are more prone to contaminate and wrinkle the *** designs,all electrically integrated are fabricated and characterized allowing us to study the effects of the introduction of a back-plate for capacitive *** devices show high mechanical compliances C_(m)=0.081-1.07μmPa^(−1)(10-100×higher than the silicon reported in the state-of-the-art diaphragms)and pull-in voltages in the range of 2-9.5 *** addition,to validate the proof of concept,we have electrically characterized the graphene microphone when subjected to sound *** estimated sensitivity of S_(1kHz)=24.3-321 mV Pa^(−1)for a V_(bias)=1.5 V was determined,which is 1.9-25.5×higher than of state-of-the-art microphone devices while having a~9×smaller area.

关键词： transfer plate approaching

来源：

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

Late corneal ectasia after penetrating and deep anterior lamellar keratoplasty for keratoconus

引用

International Journal of Ophthalmology(English edition) 2024年第10期17卷 1828-1836页

作者： Bora Yüksel Arife Esra Kocakaya Tuncay Küsbeci Fatih gümüş Department of Ophthalmology University of Health SciencesIzmir Bozyaka Education and Research HospitalIzmir 35110Türkiye

AIm:To investigate tomographic features of late corneal ectasia after keratoplasty for keratoconus and compare penetrating keratoplasty(PK)and deep anterior lamellar keratoplasty(DALK)in terms of incidence,time of onset and risk factors of corneal ***:Sixty eyes with PK and 30 eyes with DALK operated between 1999 and 2021 were *** Pentacam scans were evaluated together with vision and previous *** outcome measures were vision,K values,apparent thinning on graft-host cornea and the difference between opposing quadrants in the thinnest point *** segment optic coherence tomography was performed for further ***:mean follow-up was 127.2mo(24–282mo)in PK,and 64.3mo(24–144mo)in DALK.K max was higher in DALK(60.6 vs 56.7 D,P=0.012).Inferior recipient was thinner(595.9μm)in PK than DALK(662.2μm,P=0.021),due to longer *** corneal ectasia rate was 20.0%within *** rate was the same(6.7%)in DALK 2/30 and in PK 4/60 in 10y and 13.3%in 12y(4/30 and 8/60,respectively).It increased to 23.3%(14/60)in PK over *** ectasia was not seen before 7y in PK,it could be seen in DALK starting from the 5^(th) *** intervals between keratoplasty and ectasia were 144.5mo in PK and 99mo in *** recipient was significantly thinner in 18 eyes with ectasia(502.7μm)compared to 76 non-ectasia(649.1μm,P=0.000).Inferior graft was thinner(561.0 vs 620.4μm,P=0.006),K max(63.3 vs 56.5 D,P=0.000),and anterior elevation was higher in ectasia(89.1 vs 48.6μm,P=0.002).Accelerated crosslinking was performed on 5 ***:Inferior-superior recipient and inferior graft thinning on tomography,with high K max and anterior elevation emerge as the most reliable criteria for the diagnosis of late *** incidence of corneal ectasia increases with the time.

关键词： keratoconus penetrating keratoplasty deep anterior lamellar keratoplasty corneal ectasia

来源：

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

The Impact of a Prior Norwood Procedure on Cardiac Transplantation in Failed Fontan Physiology

引用

Congenital Heart Disease 2024年第3期19卷 257-266页

作者： Ryan g.mcQueen Nikki m.Singh Ronald K.Woods medical College of Wisconsin Herma Heart Institute at Children’s WisconsinMilwaukeeUSA Division of Pediatric Cardiology Medical College of WisconsinHerma Heart Institute at Children’s WisconsinMilwaukeeUSA Division of Pediatric Cardiothoracic Surgery Medical College of WisconsinHerma Heart Institute at Children’s WisconsinMilwaukeeUSA

Objective:The objective of this study was to compare cardiac transplant operative and postoperative courses of patients with failed Fontan physiology who were initially palliated with a Norwood(FFN)to those without a prior Norwood(FF).methods:A single-institution retrospective review of all patients with Fontan failure who under-went cardiac transplantation from 2003–2021 was completed-22 underwent prior Norwood(FFN)and 11 did not(FF).Descriptive and inferential statistics were calculated for operative course and patient ***:The operative course of the FFN cohort appeared to be more complex(not statistically significant,but clinically relevant)-this group exclusively experienced sternal re-entry events(3 of 22 patients)and concomitant neo-aor-tic reconstruction(6 patients),had a longer duration of surgery(median of 682 min vs.575.5 min),more time on circulatory arrest(median of 25.5 min vs.12.5 min),and more frequent use of open sternal management[50%of patients(11/22)vs.27.3%of patients(3/11)].Postoperatively,these patients underwent more mediastinal explora-tions[other than sternal closure;40.9%of patients(9/22)vs.18.2%of patients(2/11)],spent more time on mechanical ventilation(median of 5 days vs.2 days),had a longer length of stay(median of 30 days vs.19 days),and required more catheter-based re-interventions[22.7%of patients(5/22)vs.9.1%of patients(1/11)].Conclu-sion:Although underpowered,our results suggest that the operative course of FFN patients is more challenging,based mostly on neo-aortic arch *** turn,this likely leads to a more complex postoperative *** are currently collaborating with other institutions to increase the cohort size and power of the study.

关键词： Fontan Fontan failure Norwood cardiac transplantation

来源：

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

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

引用

Chinese Physics B 2024年第2期33卷 108-114页

作者： U.S.mahabaleshwar g.P.Vanitha L.m.Pérez Emad H.Aly I.Pop Department of Studies in mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in H_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/H_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/H_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Optimizing building retrofit through data analytics:A study of multi-objective optimization and surrogate models derived from energy performance certificates

Energy and Built Environment

引用

Energy and Built Environment 2024年第6期5卷 889-899页

作者： g.R.Araújo Ricardo gomes Paulo Ferrão m.glória gomes IN+ DEMTécnico LisboaUniversidade de lisboaAv Rovisco PaisLisboa1049-001Portugal CERIS DECivilTécnico LisboaUniversidade de LisboaAv Rovisco PaisLisboa1049-001Portugal

The building stock is responsible for a large share of global energy consumption and greenhouse gas emissions,therefore,it is critical to promote building retrofit to achieve the proposed carbon and energy neutrality *** of the policies implemented in recent years was the Energy Performance Certificate(EPC)policy,which proposes building stock benchmarking to identify buildings that require ***,research shows that these mechanisms fail to engage stakeholders in the retrofit process because it is widely seen as a mandatory and complex *** study makes use of an EPC database to integrate machine learning techniques with multi-objective optimization and develop an interface capable of(1)predicting a building’s,or household’s,energy needs;and(2)providing the user with optimum retrofit solutions,costs,and return on *** goal is to provide an open-source,easy-to-use interface that guides the user in the building retrofit *** energy and EPC prediction models show a coefficient of determination(R2)of 0.84 and 0.79,and the optimization results for one case study EPC with a 2000€budget limit inÉvora,Portugal,show decreases of up to 60%in energy needs and return on investments of up to 7 in 3 years.

关键词： Building energy performance Building optimization multi-Objective surrogate models Building retrofitting

来源：

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

In-situ construction of grass-like hybrid architecture responsible for extraordinary corrosion performance: Experimental and theoretical approach

引用

Nano materials Science 2024年第1期6卷 44-59页

作者： T.Suhartono F.Hazmatulhaq Y.Sheng A.Chaouiki m.P.Kamil Y.g.Ko materials Electrochemistry group School of Materials Science and EngineeringYeungnam UniversityGyeongsan38541Republic of Korea Research Center for Advanced materials National Research and Innovation Agency(BRIN)South TangerangBanten15314Indonesia

Despite the engineering potential by the co-existence of inorganic and organic substances to protect vulnerable metallic materials from corrosive environments,both their interaction and in-situ formation mechanism to induce the nature-inspired composite remained less *** present work used three distinctive mercaptobenzazole(mB)compounds working as corrosion inhibitors,such as 2-mercaptobenzoxazole(mBO),2-mercaptobenzothiazole(mBT),and 2-mercaptobenzimidazole(mBI)in a bid to understand how the geometrical structure arising from O,S,and N atoms affected the interaction toward inorganic *** compounds that were used here to control the corrosion kinetics would be interacted readily with the pre-existing mgO layer fabricated by plasma *** phenomenon triggered the nucleation of the root network since mB compounds were seen to be adsorbed actively on the defective surface through the active sites in mB ***,the molecule with twin donor atoms adjacent to the mercapto-sites affected the facile growth of the grass-like structures with‘uniform’distribution via molecular self-assembly,which showed better corrosion performance than those with having dissimilar donor atoms with the inhibition efficiency(η)of 97%*** formation mechanism underlying nucleation and growth behavior of mB molecule was discussed concerning the theoretical calculation of density functional theory.

关键词： Nature-inspired composite Organic-inorganic interaction Corrosion inhibitor Density functional theory Electrochemistry

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：