检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

原子核集体模式

原子核集体模式

粉末冶金Al-5.6Zn-2Mg合金在热压缩过程中加工硬化特性及本构模型的比较

丛书名：世界名著

1972年

作者： j.p.davidson 许云基译

来源：汇雅图书（南通市图书馆... 评论

在线全文

汇雅图书（南通市图书馆）

学校读者我要写书评

暂无评论

journal of Central South University 2024年第2期31卷 346-368页

作者： KATIKA Harikrishna DAMODA R.K. davidson M.j. SEETHARAM R. KASAGANI Veera Venkata Nagaraju Department of Mechanical Engineering National Institute of TechnologyWarangal 506004India Department of Mechanical Engineering The Indian Institute of Information Technology Design and ManufacturingKurnool 518007India

在300~5000℃、应变速率为0.1~0.0001 s−1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σ_(c)(ε_(c))l以及关键特征σ_(c)(ε_(c))l、σ_(p)(ε_(p))和σ_(ss)与Z系数之间的... 详细信息

在300~5000℃、应变速率为0.1~0.0001 s−1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σ_(c)(ε_(c))l以及关键特征σ_(c)(ε_(c))l、σ_(p)(ε_(p))和σ_(ss)与Z系数之间的相关性。使用了四个本构模型,Arrhenius模型、改进的johnson-Cook模型(MjC)、改进的Zerilli-Armstrong模型(MZA)和开发的人工神经网络(ANN)。结果表明,ANN型模型和Arrhenius模型的相对误差的绝对平均值最低,分别为0.486%和3.36%,MZA型模型和MjC型模型的相对误差的绝对平均值较高,分别为8.84%和3.93%。由于Arrhenius模型能够处理各种因素之间的非线性关系,因此它被认为是最合适的预测模型,但在材料性质未知或实验数据有限的情况下,MjC模型可能是一种更简单的替代方法。MZA模型不适合估计热压缩时的流变应力。此外,训练最好的神经网络模型的预测性能最好,相对误差的绝对平均值为0.486%,R值为0.99。

关键词：加工硬化速率曲线本构建模热压缩 EBSD分析流变曲线

Are there sex-based disparities in cataract surgery?

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

International journal of Ophthalmology(English edition) 2024年第1期17卷 137-143页

作者： Matthew D.Geiger Anne M.Lynch Alan G.palestine Nathan C.Grove Karen L.Christopher Richard S.davidson Michael j.Taravella Naresh Mandava jennifer L.patnaik Department of Ophthalmology University of Colorado School of MedicineAuroraCO 80045USA

AIM:To investigate sex-based differences in the occurrence of intra-operative and post-operative complications and associated visual outcomes following cataract ***:This was a retrospective study of patients who had phacoemulsification cataract surgery at the University of Colorado School of *** collected included the patient’s health history,ocular comorbidities,operative and post-operative complications,and the post-operative best corrected visual acuity(BCVA).The data were analyzed using univariate and multivariable logistic regression with generalized estimating equations to account for the correlation of some patients having two eyes included in the ***:A total of 11977 eyes from 7253 patients were included in the *** comorbidities differed by sex,with males having significantly higher percentages of traumatic cataracts(males 0.7%vs females 0.1%),prior ocular surgery(6.7%vs 5.5%),and mature cataracts(2.8%vs 1.9%).Conversely,females had significantly higher rates of pseudoexfoliation(2.0%vs 3.2%).In unadjusted analysis,males had higher rates of posterior capsular rupture(0.8%vs 0.4%)and vitreous loss(1.0%vs 0.6%),but this difference was not significant after adjustment for *** had a significantly increased risk of post-operative retinal detachment,but in multivariable analysis this was no longer *** were significantly less likely to undergo post-operative neodymium-doped yttrium aluminum garnet(Nd:YAG)laser capsulotomy for posterior capsule opacification(OR=0.8,95%CI=0.7-0.9,p=0.0005).The BCVA was slightly worse for males pre-operatively;but post-operatively,both sexes exhibited similar visual acuity of Snellen equivalent 20/***:The study finds that in a cohort of patients presenting for cataract surgery,sex differences exist in pre-operative comorbidities and surgical characteristics that contribute to higher rates of some complications for ***,observed surgical complicatio

关键词： cataract surgery sex-based disparity phacoemulsification outcomes

Challenges in developing therapeutic strategies for mild neonatal encephalopathy

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

Neural Regeneration Research 2022年第2期17卷 277-282页

作者： Alice McDouall Guido Wassink Laura Bennet Alistair j.Gunn joanne O.davidson Department of physiology The University of AucklandAucklandNew Zealand

There is increasing evidence that infants with mild neonatal encephalopathy(NE) have significant risks of mortality, brain injury and adverse neurodevelopmental outcomes. In the era of therapeutic hypothermia, infants need to be diagnosed within 6 hours of birth, corresponding with the window of opportunity for treatment of moderate to severe NE, compared to the retrospective grading over 2 to 3 days, typically with imaging and formal electroencephalographic assessment in the pre-hypothermia era. This shift in diagnosis may have increased the apparent prevalence of brain damage and poor neurological outcomes seen in infants with mild NE in the era of hypothermia. Abnormal short term outcomes observed in infants with mild NE include seizures, abnormal neurologic examination at discharge, abnormal brain magnetic resonance imaging and difficulty feeding. At 2 to 3 years of age, mild NE has been associated with an increased risk of autism, language and cognitive deficits. There are no approved treatment strategies for these infants as they were not included in the initial randomized controlled trials for therapeutic hypothermia. However, there is already therapeutic creep, with many centers treating infants with mild NE despite the limited evidence for its safety and efficacy. The optimal duration of treatment and therapeutic window of opportunity for effective treatment need to be specifically established for mild NE as the evolution of injury is likely to be slower, based on preclinical data. Randomized controlled trials of therapeutic hypothermia for infants with mild NE are urgently required to establish the safety and efficacy of treatment. This review will examine the evidence for adverse outcomes after mild NE and dissect some of the challenges in developing therapeutic strategies for mild NE, before analyzing the evidence for therapeutic hypothermia and other strategies for treatment of these infants.

关键词： asphyxia electroencephalogram erythropoietin mild hypoxic ischemic encephalopathy neonatal encephalopathy neurological examination neuroprotection Sarnat score therapeutic hypothermia

粉末冶金Al-5.6Zn-2Mg合金在热压缩过程中加工硬化特性及本构模型的比较（英文）

在线全文

学校读者我要写书评

暂无评论

journal of Central South University 2024年第2期 346-368页

作者： KATIKA Harikrishna DAMODA R.K. davidson M.j. SEETHARAM R. KASAGANI Veera Venkata Nagaraju Department of Mechanical Engineering National Institute of Technology Department of Mechanical Engineering The Indian Institute of Information Technology Design and Manufacturing

在300～5000℃、应变速率为0.1～0.0001 s-1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σc(εc)以及关键特征σc(εc)、σp(εp)和σss与Z系数之间的相关性。使用了四个本... 详细信息

在300～5000℃、应变速率为0.1～0.0001 s-1的条件下,在万能试验机上对Al-5.6Zn-2Mg铝合金进行热压缩试验,以确定动态再结晶开始时的加工硬化速率曲线σc(εc)以及关键特征σc(εc)、σp(εp)和σss与Z系数之间的相关性。使用了四个本构模型,Arrhenius模型、改进的johnson-Cook模型(MjC)、改进的Zerilli-Armstrong模型(MZA)和开发的人工神经网络(ANN)。结果表明,ANN型模型和Arrhenius模型的相对误差的绝对平均值最低,分别为0.486%和3.36%,MZA型模型和MjC型模型的相对误差的绝对平均值较高,分别为8.84%和3.93%。由于Arrhenius模型能够处理各种因素之间的非线性关系,因此它被认为是最合适的预测模型,但在材料性质未知或实验数据有限的情况下,MjC模型可能是一种更简单的替代方法。MZA模型不适合估计热压缩时的流变应力。此外,训练最好的神经网络模型的预测性能最好,相对误差的绝对平均值为0.486%,R值为0.99。

关键词：加工硬化速率曲线本构建模热压缩 EBSD分析流变曲线

Controlled generation of picosecond-pulsed higher-order poincaré sphere beams from an ytterbium-doped multicore fiber amplifier

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

photonics Research 2023年第2期11卷 181-188页

作者： KUNHAO jI DI LIN IAN A. davidson SIYI WANG jOEL CARpENTER YOSHIMICHI AMMA YONGMIN jUNG MASSIMILIANO GUASONI DAVID j. RICHARDSON Optoelectronics Research Centre University of SouthamptonSouthampton SO171BJUK Institute of Advanced photonics Technology School of Information EngineeringGuangdong University of TechnologyGuangzhou 510006China Guangdong provincial Key Laboratory of photonics Information Technology Guangdong University of TechnologyGuangzhou 510006China School of Information Technology and Electrical Engineering The University of QueenslandBrisbaneQLD 4072Australia Fujikura Ltd. Chiba 285-8550Japan

Higher-order poincarésphere(HOpS) beams with spatially variable polarization and phase distributions are opening up a host of unique applications in areas ranging from optical communication to ***, the flexible generation of these beams with high peak power from compact laser systems remains a challenge. Here, we demonstrate the controlled generation of HOpS beams based on coherent beam combination from an Yb-doped multicore fiber(MCF) amplifier. Using a spatial light modulator to adaptively adjust the wavefront and polarization of the signals seeded into the individual cores of the MCF various structured beams(including cylindrical vector beams and first-and second-order vortex beams) were generated with peak powers up to 14 k W for ~92 ps pulses.

关键词： amplifier polarization fiber

Can we further optimize therapeutic hypothermia for hypoxic-ischemic encephalopathy?

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2019年第10期14卷 1678-1683页

作者： Anthony Davies Guido Wassink Laura Bennet Alistair j.Gunn joanne O.davidson Department of physiology The University of Auckland

perinatal hypoxic-ischemic encephalopathy is a leading cause of neonatal death and *** hypothermia significantly reduces death and major disability associated with hypoxic-ischemic encephalopathy;however,many infants still experience lifelong disabilities to movement,sensation and *** guidelines,based on strong clinical and preclinical evidence,recommend therapeutic hypothermia should be started within 6 hours of birth and continued for a period of 72 hours,with a target brain temperature of 33.5 ±0.5℃ for infants with moderate to severe hypoxic-ischemic *** clinical guidelines also recommend that infants be re warmed at a rate of 0.5℃ per hour,but this is not based on strong *** are no randomized controlled trials investigating the optimal rate of rewarming after therapeutic hypothermia for infants with hypoxic-ischemic *** studies of rewarming are conflicting and results were confounded by treatment with sub-optimal durations of *** this review,we evaluate the evidence for the optimal start time,duration and depth of hypothermia,and whether the rate of rewarming after treatment affects brain injury and neurological outcomes.

关键词： hypoxia-ischemia hypoxic-ischemic encephalopathy therapeutic hypothermia neuroprotection therapeutic strategies randomized controlled trials animal models fetal sheep piglets

Study on the early surface films formed on Mg-Y molten alloy in different atmospheres

在线全文

学校读者我要写书评

暂无评论

journal of Magnesium and Alloys 2015年第3期3卷 173-179页

作者： A.R.Mirak C.j.davidson j.A.Taylor CAST CRC School of Mechanical and Mining EngineeringThe University of QueenslandBrisbaneQLD 4072Australia CAST CRC CSIRO Materials Science and EngineeringP.O.Box 883KenmoreQLD 4069Australia

In the present study,the non-isothermal early stages of surface oxidation of liquid Mg-1%Y alloy during casting were studied under UpH argon,dry air,and air mixed with protective fluorine-bearing *** chemistry and morphology of the surface films were characterized by SEM and EDX *** results indicate a layer of smooth and tightly coherent oxidation film composed of MgO and Y_(2)O_(3) formed on the molten Mg-Y alloy surface with 40-60 nm thickness under dry air.A dendritic/cellular microstructure is clearly visible with Y-rich second phases gathered in surface of the melt and precipitated along the grain/cell boundaries under all gas *** fluorine-bearing gas mixtures,the surface film was a mixed oxide and fluoride and more even;a flat and folded morphology can be seen under SF6 with oxide as dominated phase and under 1,1,1,2-tetra-fluoroethane,a smooth and compact surface film uniformly covering the inner surface of the bubble with equal oxide and fluoride thickness,which results in a film without any major ***_(2) phase appears to be the key characteristic of a good protective film.

关键词： Mg-Y alloy SEM EDX Early surface film Oxidation Fluoridation

Gas flow in rotary kilns

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

particuology 2010年第6期8卷 613-616页

作者： patrick R.Davies Michael j.S.Norton D.Ian Wilson john F.davidson David M.Scott Department of Chemical Engineering and Biotechnology University of CambridgePembroke StreetCambridgeCB2 3RAUK

This paper describes an experimental investigation on the flow characteristics within a rotating cylinder containing a rolling bed of sand. The axis of the cylinder was horizontal and there was no axial bulk flow of particles. The velocity field of the gas flowing through the cylinder was measured by hot-wire anemometry. The measurements indicate that the velocity field is asymmetric with respect to a diameter perpendicular to the granular bed. CFD calculations confirm this finding. The gas velocity profiles are crucial in determining heat transfer from gas to solid.

关键词： Rotating cylinderVelocity profile