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通过使用耦合换热模型模拟通过柴油机活塞的热损失和研究热障涂层对换热损失的影响规律

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汽车与新动力 2018年第4期1卷 58-64页

作者： P.Kundu[美] R.scarcelli[美] s.som[美] A.Ickes[美] Y.Wang[美] J.Kiedaisch[美] M.Rajkumar[美] 闫红梅(译) 陈建伟(译)

壁面边界产生的热损失对内燃机的整体性能和效率起主要作用。通常恒温壁边界条件用于典型的发动机模拟开发[1-3]。由于涉及到发动机燃烧的复杂性,这些边界条件不能从试验中精确估计。因此,在发动机模拟中,这些边界条件引起了很多的不确... 详细信息

壁面边界产生的热损失对内燃机的整体性能和效率起主要作用。通常恒温壁边界条件用于典型的发动机模拟开发[1-3]。由于涉及到发动机燃烧的复杂性,这些边界条件不能从试验中精确估计。因此,在发动机模拟中,这些边界条件引起了很多的不确定性和不定参数。在非稳态发动机计算流体动力学(CFD)模拟中通过实体壁的热传递过程建模,开发出更高精度的发动机模型。这些发动机模型可用于研究热损失对发动机效率的影响,并用于研究减少热损失的新设计方法。利用单缸柴油机与连接到流体域的固体活塞一起建模,通过耦合热传递(CHT)建模技术,模拟Navistar柴油机的完整循环热损失,然后根据嵌入在活塞表面内的热电偶的试验数据验证该CFD模型。来自模型的总体预测与试验观察紧密地匹配。经过验证的发动机模型被进一步用于探索热障涂层(TBC)应用于活塞燃烧室上的优点。TBC涂层产生的效果在热传递模型建模中被设定为热阻。全周期3D发动机模拟提供了对热损失的定量分析,从而提高了使用TBC涂层的计算效率,为往复式发动机的CHT建模建立了可靠的框架。

关键词：耦合换热模型热障涂层计算机流体动力学柴油机热损失

synthetic data as an investigative tool in hypertension and renal diseases research

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World Journal of Methodology 2025年第1期15卷 9-13页

作者： Aleena Jamal som singh Fawad Qureshi sidney Kimmel Medical College Thomas Jefferson UniversityPhiladelphiaPA 19107United States school of Medicine University of Missouri Kansas CityKansasMO 64106United States Division of Nephrology and Hypertension Mayo ClinicRochesterMN 55905United States

There is a growing body of clinical research on the utility of synthetic data derivatives,an emerging research tool in *** nephrology,clinicians can use machine learning and artificial intelligence as powerful aids in their clinical decision-making while also preserving patient *** is especially important given the epidemiology of chronic kidney disease,renal oncology,and hypertension ***,there remains a need to create a framework for guidance regarding how to better utilize synthetic data as a practical application in this research.

关键词： synthetic data Artificial intelligence Nephrology Blood pressure Research Editorial

socio-economic determinants of underweight children in West Bengal,India

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Asian Pacific Journal of Tropical Medicine 2010年第4期3卷 322-327页

作者： Bharati s Chakrabarty s.som s Pal M Bharati P sociological Research Unit Indian Statistical Institute203 B.T.RoadKolkata 700 108West BengalIndia Biological Anthropology Unit Indian Statistical Institute203 B.T.RoadKolkata 700 108West BengalIndia Economic Research Unit Indian Statistical Institute203 B.T.RoadKolkata 700 108West BengalIndia Biological Anthropology Unit Indian Statistical Institute203 B.TRoadKolkata 700 108West BengalIndia

Objective:To study the extent of undernutrition at district level and the socio-economic determinants of underweight children aged 0-71 months in West ***:The data were accessed from the Reproductive and Child Health survey(RCHs-II),which contained information of 7 ssO children and their *** of socio-economic variables about the associated families of these children had also been taken for our *** study computed weight-for-age z-scores to assess the nutritional status of the children using WHO(2006) ***:The prevalence of underweight varied over the *** with very high prevalence of underweight children were Murshidabad,Burdwan,Purulia,Medinipur, Howrah and south 24 *** prevalent districts for both boys and girls were Jalpaiguri and *** prevalent districts for both boys and girls were south Dinajpur,Nadia and *** percentage of underweight children were more in rural areas among Muslim families with illiterate parents and low standard of *** Murshidabad,Bankura,Nadia, Medinipur and south 24 Parganas districts,i.e.,where prevalence of underweight children were higher,the rural and urban differences were *** characteristics like religion,parents’ educational status and standard of living index showed significant effect on the children’s ***:Public intervention programs on the parent’s education and the standard of living of the households at district level should be given high priority to combat the children’s undernutrition problems so far as weight for age is concerned.

关键词： Underweight Children socio-economic determinants West Bengal India

Characterization of optical transitions of Eu^(3+) in lanthanum oxychloride nanophosphor

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Journal of Rare Earths 2011年第4期29卷 345-348页

作者： A. Choubey s. som M. Biswas s.K. sharma Department of Applied Physics Indian School of Mines Dhanbad 826004 India

This paper presented the studies on the optical properties and calculation of spectral parameters of europium doped lanthanum oxychloride nanophosphor for their possible applications in optoelectronic devices. The compound was doped with 0.1 mol% Eu3＋ ions. The X-ray diffraction study of prepared sample suggested the tetragonal structure with particle size in the range of 18–21 nm. The photoluminescence （PL） emission spectra showed the bright emission in orange-red region from 580 to 630 nm. The most intense emission peak at 621 nm was due to transition 5D0→7F2 in energy levels of Eu3＋ ions. The spectral parameters were calculated from the absorption and emission spectra using Judd-Ofelt intensity parameters. The calculated values of the oscillator strength corresponding to the three transitions 7F1→5D1, 7F1→5D2 and 7F0→5D2 observed at 535, 472 and 465 nm in absorption spectra were 0.30×10–6, 1.36×10–6 and 0.63×10–6, respectively. The value of transi- tion probability （A）, stimulated emission cross-section （） and radiative lifetime （τrad） corresponding to 621 nm emission peak （transition 5D0→7F2） were 308 s–1, 1.22×10–21 cm2 and 3.24×10–3 s, respectively.

关键词： X-ray diffraction optical absorption photoluminescence spectral parameters rare earths

Core shell Au Ag Nanoparticles in Dielectric Nanocomposites with Plasmon-Enhanced Fluorescence: A New Paradigm in Antimony Glasses

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Nano Research 2009年第8期2卷 607-616页

作者： Tirtha som Basudeb Karmakar Glass Technology Laboratory Glass DivisionCentral Glass and Ceramic Research Institute(Council of Scientifi c and Industrial Research)196Raja S.C.Mullick RoadKolkata 700032India

The nano era demands the synthesis of new nanostructured materials,if possible by simplified techniques,with remarkable properties and versatile ***,we demonstrate a new single-step reproducible melt-quench methodology to fabricate core-shell bimetallic(Au0 Ag0)nanoparticles(2889 nm)embedded glasses(dielectrics)by the use of a new reducing glass matrix,K_(2)O B_(2)O_(3) sb_(2)O_(3)(KBs)without applying any external reducing agent or multiple processing *** surface plasmon resonance(sPR)band of these nanocomposites embedded in KBs glass is tunable in the range 554-681 *** remarkably,taking advantage of the selective reduction capability of sb_(2)O_(3),this single-step methodology is used to fabricate inter-metallic:rare-earth ions co-embedded(AuAg:sm^(3+))dielectric(glass)-based-dnanocomposites and study the effect of enhanced local fi eld on the red upconversion fl uorescence of sm^(3+)ions at 636 *** enhancement is found to be about 2 *** single-step in-situ selective reduction approach can be used to fabricate a variety of hybrid-nanocomposite devices for laser based applications(see supplementary information).

关键词： Gold-silver nanostructures core-shell morphology surface plasmon resonance antimony glass metal-enhanced rare earth fl uorescence

A multicountry comparison of cryptocurrency vs gold: Portfolio optimization through generalized simulated annealing

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Blockchain(Research and Applications) 2022年第3期3卷 23-35页

作者： Ankit som Parthajit Kayal Madras school of Economics Chennai600025India

The last few years have seen a paradigm shift in the financial sector with the development of cryptocurrencies as an alternative mode of payment as well as an investment *** aim of this study is *** first is to quantify the volatility of cryptocurrencies in terms of the dynamics of tail-end behavior using different approaches and choose the one with the lowest *** second is to investigate the effect of its inclusion in a portfolio with and without gold,to see if Bitcoin is indeed the“digital gold”.This paper uses the generalized simulated annealing optimization technique to compare portfolios for ten countries across the *** data provide convincing evidence in favor of the inclusion of Bitcoin in the optimized ***-window analyses(three-year and five-year)confirm the ***,for some countries,the empirical pattern suggests that instead of replacing gold from the portfolio,both should be *** results are robust in terms of the inclusion of non-linear constraints.

关键词： Cryptocurrency Gold Value-at-risk Portfolio optimization Generalized simulated annealing

Hill slope instability of Nainital City,Kumaun Lesser Himalaya,Uttarakhand,India

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第2期10卷 280-289页

作者： Nirvan sah Mohit Kumar Rajeev Upadhyay som Dutt Department of Geology(CAs) Kumaun UniversityNainital263001India Wadia Institute of Himalayan Geology 33 General Mahadeo Singh RoadDehradun248001India

Nainital City of Kumaun Lesser Himalaya is prone to mass wasting processes during monsoon season,which mischievously triggers the hill slope instability in this region. slate, dolomitic limestone, silty sandstone and rhythmite of the Krol Formation are the main rock types. The present study focuses on the investigation of slope stability in the region in terms of potential seismicity and landslide. Geological and geotechnical mapping indicates that the major portion of the area is characterized by slope wash materials and buildings. The combination of 3-4 joint sets with one random joint is the main structure at *** major geological structures of this area are Nainital lake fault passing from the center of the lake, Main Boundary Thrust at sW, and Khuriya Fault passing from the sE direction of Nainital City. This work finds that different types of discontinuities(e.g. joints and faults), overburden due to unplanned civil structures,and neotectonic activity in the vicinity of this ara affect the stability of the city. The slate forms the base of the city, dipping slightly towards the lake side along the NW direction, thus accelerating the instability of this area. Rock mass rating(RMR), slope mass rating, factor of safety(FOs) and graphical analysis of the discontinuity for slope kinematics indicate that the study area is a landslide-prone zone. This study can facilitate reducing the risk of human life, and contribute to the ongoing construction works in the area.

关键词： Hill slope instability Himalaya region Wedge failure Rock mass rating(RMR) Factor of safety(FOs)

Analysis of the current density characteristics in through-mask electrochemical micromachining(TMEMM) for fabrication of micro-hole arrays on invar alloy film

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Chinese Journal of Aeronautics 2017年第3期30卷 1231-1241页

作者： Da-som JIN Kwang-ho CHUN Eun-sang LEE school of Mechanical Engineering Inha University Incheon 22212 Republic of Kore Department of Mechanical Engineering Inha University Incheon 22212 Republic of Korea

Invar alloy consisting of 64% iron and 36% nickel has been widely used for the production of shadow masks for organic light emitting diodes（OLEDs） because of its low thermal expansion coefficient（1.86 × 10^-6cm/°C）.To fabricate micro-hole arrays on 30 lm invar alloy film,through-mask electrochemical micromachining（TMEMM） was developed and combined with a portion of the photolithography etching *** precise hole shapes,patterned photoresist（PR） film was applied as an insulating *** investigate the relationship between the current density and the material removal rate,the principle of the electrochemical machining was studied with a focus on the *** finite element method（FEM） was used to verify the influence of each parameter on the current density on the invar alloy film *** parameters considered were the thickness of the PR mask,inter-electrode gap（IEG）,and electrolyte *** of experiments（DOE） was used to figure out the contribution of each parameter.A simulation was conducted with varying parameters to figure out their relationships with the current *** was conducted to select the suitable *** experiment was carried out to verify the simulation *** was possible to fabricate micro-hole arrays on invar alloy film using TMEMM,which is a promising method that can be applied to fabrications of OLEDs shadow masks.

关键词： Electrochemical Invar alloy film Micromachining OLED shadow mask Photoresist film mask(PR film mask) Through-mask electrochemical micromachining(TMEMM)

Capillary Electrophoresis for the simultaneous Determination of Metals by Using Ethylenediamine Tetraacetic Acid as Complexing Agent and Vancomycin as Complex selector

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Chinese Journal of Chemistry 2006年第12期24卷 1747-1753页

作者： THREEPROM Jirasak som-AUM Waraporn 林金明 The Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology Department of Chemistry Tsinghua University Beijing 100084 China Department of Chemistry Faculty of Science Mahasarakham University Mahasarakham 44150 Thailand

A new separation system of capillary electrophoresis for the simultaneous determination of metals by using ethylenediamine tetraacetic acid （EDTA） as complexing agent and employing vancomycin as complex selector was described. The Z-shape cell capillary electrophoresis was used to enhance the sensitivity for the determination of the complexes of Cu（Ⅱ）, Ni（Ⅱ）, Co（Ⅱ） and Fe（Ⅲ） with EDTA. The partial filling method （co-current mode） was used in order to increase the selectivity of the electrophoretic method, meanwhile vancomycin was not present at the detector path during the detection of metal-EDTA complexes. The vancomycin concentration, phosphate concentration and pH of the buffer strongly influenced mobility, resolution and selectivity of the studied analytes. Under the optimal condition, the relative standard deviations （n=5） of the migration time and the peak area were less than 3.14% and 7.35%, respectively. Application of the Z-shape cell capillary electrophoresis method with UV detection and vancomycin loading led to the reliable determination of these metal ions in tap water and the recoveries were 97%-101%. The detection limits based on a signal to noise ratio of 3 ： 1 were found in the range of 2-10 μg·L^-1.

关键词： Z-shape cell capillary electrophoresis vancomycin metal ion ethylenediamine tetraacetic acid