检索结果-南通市图书馆

Heating of nanoparticles and their environment by laser radiation and applications

Nanotechnology and Precision Engineering 2024年第1期7卷 78-115页

作者： victor K.Pustovalov Belarusian National Technical University Pr.Independency65Minsk 220013Belarus

This review considers the fundamental dynamic processes involved in the laser heating of metal nanoparticles and their subsequent *** particular interest are the absorption of laser energy by nanoparticles,the heating of a single nanoparticle or an ensemble thereof,and the dissipation of the energy of nanoparticles due to heat exchange with the *** goal is to consider the dependences and values of the temperatures of the nanoparticles and the environment,their time scales,and other parameters that describe these *** results and analytical studies on the heating of single metal nanoparticles by laser pulses are discussed,including the laser thresholds for initiating subsequent photothermal processes,how temperature inﬂuences the optical properties,and the heating of gold nanoparticles by laser *** studies of the heating of an ensemble of nanoparticles and the results of an analytical study of the heating of an ensemble of nanoparticles and the environment by laser radiation are *** methods for nanoparticles under laser heating are considered,including changes in the refractive indices of metals and spectral thermometry of optical scattering of nanoparticles,Raman spectroscopy,the thermal distortion of the refractive index of an environment heated by a nanoparticle,and thermochemical phase transitions in lipid bilayers surrounding a heated *** the sequence of events after radiation absorption and their time scales underlies many applications of *** applicationﬁelds for the laser heating of nanoparticles are reviewed,including thermochemical reactions and selective nanophotothermolysis initiated in the environment by laser-heated nanoparticles,thermal radiation emission by nanoparticles and laser-induced incandescence,electron and ion emission of heated nanoparticles,and optothermal chemical *** of the laser heating of nanoparticles in la

关键词： Nanoparticles Laser Heating Modeling Nanothermometry Applications

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

Extending blending proportions of ordinary Portland cement and calcium sulfoaluminate cement blends:Its effects on setting,workability,and strength development

引用

Frontiers of Structural and Civil Engineering 2021年第5期15卷 1249-1260页

作者： Guangping HUANG Deepak PUDASAINEE Rajender GUPTA Wei victor LIU Department of Civil and Environmental Engineering University of AlbertaEdmonton T6G 1H9Canada Department of Chemical and Materials Engineering University of AlbertaEdmonton T6G 1H9Canada

This study extended blending proportion range of ordinary Portland cement(OPC)and calcium sulfoaluminate(CSA)cement blends,and investigated effects of proportions on setting time,workability,and strength development of OPC-CSA blend-based *** analysis(TGA)and X-ray diffraction(XRD)were conducted to help understand the performance of OPC-CSA blend-based *** setting time of the OPC-CSA blends was extended,and the workability was improved with increase of OPC *** the early-age strength decreased with increase of OPC content,the strength development was still very fast when the OPC content was lower than 60%due to the rapid formation and accumulation of *** 2 h,the OPC-CSA blend-based mortars with OPC contents of 0%,20%,40%,and 60%achieved the unconfined compressive strength(UCS)of 17.5,13.9,9.6,and 5.0 MPa,*** OPC content had a negligible influence on long-term *** 90 d,the average UCS of the OPC-CSA blend-based mortars was 39.2±1.7 MPa.

关键词： calcium sulfoaluminate cement cement blends hydration reaction setting workability compressive strength

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

Appraising the potential of calcium sulfoaluminate cement-based grouts in simulated permafrost environments

引用

Frontiers of Structural and Civil Engineering 2023年第5期17卷 722-731页

作者： Jian ZHAO Guangping HUANG Lin LIAO Wei victor LIU Department of Civil and Environmental Engineering University of AlbertaEdmonton T6G 1H9Canada College of Mining Engineering Taiyuan University of TechnologyTaiyuan 030024China

The aim of this study is to appraise the potential of calcium sulfoaluminate(CSA)cement-based grouts in simulated permafrost *** hydration and performance of CSA cement-based grouts cured in cold environments(10,0,and−10℃)are investigated using a combination of tests,including temperature recording,X-ray diffraction(XRD)tests,thermogravimetric analysis(TGA),and unconfined compressive strength(UCS)*** recorded temperature shows a rapid increase in temperature at the early stage in all the ***,results of the TGA and XRD tests show the generation of a significant quantity of hydration products,which indicates the rapid hydration of CSA cement-based grouts at the early stage at low ***,the CSA cement-based grouts exhibit remarkably high early *** UCS values of the samples cured for 2 h at−10,0,and 10℃ are 6.5,12.0,and 12.3 MPa,*** UCS of the grouts cured at−10,0,and 10℃ increases continuously with age and ultimately reached 14.9,19.0,and 30.6 MPa at 28 d,*** findings show that the strength of grouts fabricated using CSA cement can develop rapidly in cold environments,thus rendering them promising for permafrost applications.

关键词： permafrost low temperatures calcium sulfoaluminate cement-based grouts hydration reaction compressive strength

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

Implicit large eddy simulation of unsteady cloud cavitation around a plane-convex hydrofoil

引用

Journal of Hydrodynamics 2015年第6期27卷 815-823页

作者： HIDALGO victor 罗先武 ESCALER Xavier 季斌 AGUINAGA Alvaro Beijing Key Laboratory of CO2 Utilization and Reduction Technology Tsinghua University CDIF Universitat Politècnica de Catalunya School of Power and Mechanical Engineering Wuhan University Mechanical Engineering Department Escuela Politecnica Nacional University

The present paper focuses on the erosive cavitation behavior around a plane convex hydrofoil. The Zwart-Gerber-Belamri cavitation model is implemented in a library form to be used with the OpenFOAM. The implicit large eddy simulation （ILES） is app- lied to analyze the three-dimensional unsteady cavitating flow around a plane convex hydrofoil. The numerical results in the cases under the hydrodynamic conditions, which were experimentally tested at the high speed cavitation tunnel of the l^cole Polytechnique F6d＆ale de Lausanne （EPFL）, clearly show the sheet cavitation development, the shedding and the collapse of vapor clouds. It is noted that the cavitation evolutions including the maximum vapor length, the detachment and the oscillation frequency, are captured fairly well. Furthermore, the pressure pulses due to the cavitation development as well as the complex vortex structures are reasona- bly well predicted. Consequently, it may be concluded that the present numerical method can be used to investigate the unsteady cavitation around hydrofoils with a satisfactory accuracy.

关键词： implicit large eddy simulation (ILES) unsteady partial cavitation Zwart-Gerber-Belamri cavitation model OpenFOAM,Q - criterion

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

A novel artificial intelligent model for predicting air overpressure using brain inspired emotional neural network

引用

International Journal of Mining Science and Technology 2020年第5期30卷 683-689页

作者： victor Amoako Temeng Yao Yevenyo Ziggah Clement Kweku Arthur Department of Mining Engineering Faculty of Mineral Resources TechnologyUniversity of Mines and TechnologyTarkwaWestern RegionGhana Department of Geomatic Engineering Faculty of Mineral Resources TechnologyUniversity of Mines and TechnologyTarkwaWestern RegionGhana

Blasting is the live wire of mining and its operations,with air overpressure(AOp)recognised as an end product of *** is known to be one of the most important environmental hazards of *** research in this area of mining is required to help improve on safety of the working *** of previous studies has shown that many empirical and artificial intelligence(AI)methods have been proposed as a forecasting *** an alternative to the previous methods,this study proposes a new class of advanced artificial neural network known as brain inspired emotional neural network(BIENN)to predict *** proposed BI-ENN approach is compared with two classical AOp predictors(generalised predictor and McKenzie formula)and three established AI methods of backpropagation neural network(BPNN),group method of data handling(GMDH),and support vector machine(SVM).From the analysis of the results,BI-ENN is the best by achieving the least RMSE,MAPE,NRMSE and highest R,VAF and PI values of 1.0941,0.8339%,0.1243%,0.8249,68.0512%and 1.2367 respectively and thus can be used for monitoring and controlling AOp.

关键词： Air overpressure Artificial intelligence Emotional neural network Blasting Mining

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

Late Cryogenian glaciation in South Australia:Fluctuating ice margin and no extreme or rapid post-glacial sea-level rise

引用

Geoscience Frontiers 2019年第4期10卷 1397-1408页

作者： George E.Williams victor A.Gostin Department of Earth Sciences University of Adelaide

Postulated extreme sea-level rise of up to 1-1.5 km with the late Cryogenian Ghaub deglaciation in Namibia is contentious,as is the great rapidity(<104 yr)of the sea-level *** extreme glacioeustatic events,if real,would have been global and affected all *** South Australia,up to six glacial advances and retreats during the late Cryogenian Elatina glaciation indicate a fluctuating ice *** latter stage of the Elatina glaciation and the immediate post-glacial environment are examined here for evidence of extreme and rapid sea-level *** the central Adelaide Rift Complex,diamictite with faceted and striated clasts occurs at the top of the Elatina Formation<1-2 m beneath the early Ediacaran Nuccaleena Formation’cap carbonate’.One hundred kilometres to the south,~30 m of siltstone and sandstone followed by^6 m of clast-poor diamictite with clasts 10+cm long occur between tidal rhythmites and the cap *** hundred kilo metres further south,~70 m of siltsto ne,dolo mitic siltstone and minor dolomite separate tidal rhythmites and early Ediacaran *** the rhythmites were deposited during a high stand(interstadial or interglacial),not during post-glacial sea-level ***-generated erosional surfaces within tidal rhythmites at Warren Gorge indicate intermittent rhythmite deposition,and water depth and other palaeoenvironmental factors are uncertain,casting doubt on a published estimate of rapid sea-level rise during rhythmite *** lack of late Cryogenian deeply incised valleys and thick valley-fill deposits in South Australia and central Australia argues against extreme sea-level variations.A hiatus occurred between Elatina deglaciation and deposition of the Nuccaleena cap carbonate,and three palaeomagnetic polarity chrons identified in the cap carbonate imply slow deposition spanning 10^5-10^6 *** is supported by independent evidence from magnetic chronostratigraphy for Ediacaran strata in South Australia and Califo

关键词： Late Cryogenian glaciation Sea level Adelaide Rift Complex Elatina Formation Nuccaleena Formation

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

TiO_(2)/WO_(3)heterogeneous structures prepared by electrospinning and sintering steps:Characterization and analysis of the impedance variation to humidity

引用

Journal of Advanced Ceramics 2019年第2期8卷 238-246页

作者： Evando S.ARAuJO victor N.S.LEAO Research Group on Electrospinning and Nanotechnology Applications(GPEA-Nano) Department of Materials ScienceUniversidade Federal do Vale do Sao Francisco

Relative humidity(RH) is a critical environmental variable for transportation and storage of products and for the quality guarantee of several other production processes and services. Heterogeneous structures prepared from the selective semiconductor oxides may improve the sensitivity to humidity due to the better electronic and surface properties, when compared to pristine oxides. This work shows an alternative fabrication route for producing titanium dioxide/tungsten trioxide(TiO2/WO3) heterogeneous structures(by electrospinning and sintering) for potential application on the RH detection. The microstructural properties of the materials were analyzed by scanning electron microscopy(SEM), energy dispersive X-ray analysis(EDS), X-ray diffraction, and Raman spectroscopy. The electrical characterization of the structures was performed by electrical impedance spectroscopy in RH range of 10%–100%. Results indicated a p-to n-type conduction transition at around 30%–40% RH for all tested settings. The analysis of the impedance signature to humidity showed that the amount of fiber layers on the electrode and working temperature are important parameters to improve the humidity sensing of the TiO2/WO3 systems.

关键词： electrospinning heterogeneous structures preparation relative humidity semiconductors

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

Some problerns in adsorption and calorimetric studies of the steps of catalytic processes

引用

Journal of Natural Gas Chemistry 2004年第3期13卷 123-147页

作者： victor E.Ostrovskii Karpov Institute of Physical Chemistry ul. Vorontsovo Pole 10 Moscow 105064 Russiarincipal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts of falsifying the nature of the processes proceeding in the systems under study and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but due to imperfections of chemisorption techniques show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.

Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but, due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.

关键词： adsorption techniques and procedures adsorption and calorimetric artifacts calorimetric and chemisorption techniques chemisorption heats catalytic mechanisms chemisorption mechanisms heats of adsorption.

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

Positive and negative streamers in air and nitrogen in a sharply inhomogeneous electric field under conditions of runaway electron generation

引用

High Voltage 2023年第3期8卷 527-537页

作者： Dmitry Beloplotov victor Tarasenko Dmitry Sorokin Cheng Zhang Tao Shao Institute of High Current Electronics Siberian Branch of the Russian Academy of ScienceTomskRussia Beijing International S&T Cooperation Base for Plasma Science and Energy Conversion Institute of Electrical EngineeringChinese Academy of SciencesBeijingChina

The development of positive and negative streamers in a point-to-plane gap filled with air and nitrogen at various pressures(50-200 kPa)and voltages(8-25 kV)was studied.A four-channel intensified charge-coupled device(ICCD)and a streak-camera were *** parameters were measured with high resolution(10 GHz).An original method of measuring a displacement current caused by a streamer was *** was expected,positive streamer branches in nitrogen at low voltages and/or elevated pressures while a large-diameter streamer is formed in ***,at high voltages or negative polarity,the large-diameter streamer is formed both in nitrogen and air in the entire pressure *** was found that runaway electrons(REs)are generated in the very first picoseconds of gas ionisation near the pointed *** was assumed that REs can be generated near the pointed anode and produce bremsstrahlung radiation due to a sharply inhomogeneous distribution of electrical *** was found that in the final stage of negative streamer development in air and nitrogen,the gas between the streamer front and the opposite electrode is ionised almost simultaneously in the entire volume when the streamer diameter is almost equal to the interelectrode gap.

关键词： sharply inhomogeneous electrode

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

Evaluation of different Krylov subspace methods for simulation of the water faucet problem

引用

Nuclear Science and Techniques 2021年第5期32卷 1-16页

作者： Hong-Yang Wei Kevin Briggs victor Quintanilla Yi-Tung Chen Department of Mechanical Engineering University of NevadaLas VegasNV 89154USA

In this study,a one-dimensional two-phase flow four-equation model was developed to simulate the water faucet *** performance of six different Krylov subspace methods,namely the generalized minimal residual(GMRES),transpose-free quasi-minimal residual,quasi-minimal residual,conjugate gradient squared,biconjugate gradient stabilized,and biconjugate gradient,was evaluated with and without the application of an incomplete LU(ILU)factorization preconditioner for solving the water faucet *** simulation results indicate that using the ILU preconditioner with the Krylov subspace methods produces better convergence performance than that without the ILU *** the GMRES demonstrated an acceptable convergence performance under the Krylov subspace methods without the *** velocity and pressure distribution in the water faucet problem could be determined using the Krylov subspace methods with an ILU preconditioner,while GMRES could determine it without the need for a ***,there are significant advantages of using an ILU preconditioner with the GMRES in terms of *** different Krylov subspace methods showed similar performance in terms of computational efficiency under the application of the ILU preconditioner.

关键词： Water faucet problem Krylov subspace methods ILU preconditioner

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：