检索结果-南通市图书馆

Characteriz.tion of bright betatron radiation generated by direct laser acceleration of electrons in plasma of near critical density

引用

Matter and Radiation at Ex.remes 2024年第2期9卷 26-35页

作者： J.Cikhardt M.Gyrdymov S.z.hter P.Tavana M.M.Günther N.Bukharskii N.Borisenko J.Jacoby x.F.Shen A.Pukhov N.E.Andreev O.N.Rosmej Faculty of Electrical Engineering Czech Technical University in Prague16627 Prague 6Czech Republic Goethe University FrankfurtMax-von-Laue-Straße 160438 Frankfurt am MainGermany GSI Helmholtz.entrum für Schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany Focused Energy GmbH Im Tiefen See 4564293 DarmstadtGermany National Research Nuclear University MEPhI Kashirskoe shosse 31115409 MoscowRussian Federation Lebedev Physical Institute RAS Leninskiy Prospekt 53119991 MoscowRussian Federation Heinrich-Heine-University Düsseldorf Universitätsstrasse 1DüsseldorfGermany Joint Institute for High Temperatures RASIzhorskaya st.13Bldg.2125412 MoscowRussian Federation Moscow Institute of Physics and Technology Institutskiy Pereulok 9141700 DolgoprudnyRussia

Directed x.rays produced in the interaction of sub-picosecond laser pulses of moderate relativistic intensity with plasma of near-critical density are investigated. Synchrotron-like (betatron) radiation occurs in the process of direct laser acceleration (DLA) of electrons in a relativisticlaser channel when the electrons undergo transverse betatron oscillations in self-generated quasi-static electric and magnetic fields. In anex.eriment at the PHELIx.laser system, high-current directed beams of DLA electrons with a mean energy ten times higher than the ponderomotive potential and max.mum energy up to 100 MeV were measured at 10^(19) W/cm^(2)laser intensity. The spectrum of directed x.raysin the range of 5–60 keV was evaluated using two sets of Ross filters placed at 0°and 10°to the laser pulse propagation ax.s. The differential x.ray absorption method allowed for absolute measurements of the angular-dependent photon fluence. We report 10^(13) photons/sr withenergies >5 keV measured at 0°to the laser ax.s and a brilliance of 10^(21) photons s^(−1) mm^(−2) mrad−2(0.1%BW)−1. The angular distributionof the emission has an FWHM of 14°–16°. Thanks to the ultra-high photon fluence, point-like radiation source, and ultra-short emissiontime, DLA-based keV backlighters are promising for various applications in high-energy-density research with kilojoule petawatt-class laserfacilities.

关键词： laser acceleration critical

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

Dynamics of a rotating ring-stiffened sandwich conical shell with an aux.tic honeycomb core

引用

Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 963-982页

作者： S.JAHANGIRI A.GHORBANPOUR ARANI z.KHODDAMI MARAGHI Department of Solid Mechanics Faculty of Mechanical EngineeringUniversity of KashanKashan ***Iran Faculty of Engineering Mahallat Institute of Higher EducationMahallat ***Iran

The free vibration analysis of a rotating sandwich conical shell with a reentrant aux.tic honeycomb core and homogenous isotropic face layers reinforced with a ring support is *** shell is modeled utiliz.ng the first-order shear deformation theory(FSDT)incorporating the relative,centripetal,and Coriolis accelerations alongside the initial hoop tension created by the *** governing equations,compatibility conditions,and boundary conditions are attained using Hamilton’s *** trigonometric functions,an analytical solution is derived in the circumferential direction,and a numerical one is presented in the meridional direction via the differential quadrature method(DQM).The effects of various factors on the critical rotational speeds and forward and backward frequencies of the shell are *** present work is the first theoretical work regarding the dynamic analysis of a rotating sandwich conical shell with an aux.tic honeycomb core strengthened with a ring support.

关键词： free vibration conical shell rotating shell ring support aux.tic honeycomb

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

Fire resistance evaluation through synthetic fire tests and generative adversarial networks

引用

Frontiers of Structural and Civil Engineering 2024年第4期18卷 587-614页

作者： Aybike Öz.üksel Çiftçioğlu M.z.Naser Department of Civil Engineering Manisa Celal Bayar University45140Türkiye School of Civil&Environmental Engineering and Earth Sciences(SCEEES) Clemson UniversityClemsonSC 29631USA Artificial Intelligence Research Institute for Science and Engineering(AIRISE) Clemson UniversityClemsonSC 29631USA

This paper introduces a machine learning approach to address the challenge of limited data resulting from costly and time-consuming fire ex.eriments by enlarging small fire test data sets and predicting the fire resistance of reinforced concrete *** approach begins by creating deep learning models,namely generative adversarial networks and variational autoencoders,to learn the spatial distribution of real fire *** then use these models to generate synthetic tabular samples that closely resemble realistic fire resistance values for reinforced concrete *** generated data are employed to train state-of-the-art machine learning techniques,including Ex.reme Gradient Boost,Light Gradient Boosting Machine,Categorical Boosting Algorithm,Support Vector Regression,Random Forest,Decision Tree,Multiple Linear Regression,Polynomial Regression,Support Vector Machine,Kernel Support Vector Machine,Naive Bayes,and K-Nearest Neighbors,which can predict the fire resistance of the columns through regression and *** learning analyses achieved highly accurate predictions of fire resistance values,outperforming traditional models that relied solely on limited ex.erimental *** study highlights the potential for using machine learning and deep learning analyses to revolutioniz. the field of structural engineering by improving the accuracy and efficiency of fire resistance evaluations while reducing the reliance on costly and time-consuming ex.eriments.

关键词： deep learning fire resistance generative adversarial networks machine learning

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

Orthogonal polynomial ex.ansions for the valuation ofoptions under the stochastic volatility models with stochastic correlation

引用

Journal of Management Science and Engineering 2024年第2期9卷 239-253页

作者： Kevin z.Tong Department of Mathematics and Statistics University of Ottawa585 King EdwardOttawaOntarioK1N 6N5Canada

This work provides a new method for pricing options under the generaliz.d stochastic volatility models with Jacobi stochastic *** method is based on the observation that the generaliz.d models belong to the class of polynomial diffusions and therefore the option prices can be efficiently computed via orthogonal polynomial *** take the Heston and Schöbel-z.u models with stochastic correlation as two specific ex.mples and are able to derive the analytical formulas for the option *** also illustrate the accuracy of the proposed method through a number of numerical ex.eriments.

关键词： Orthogonal polynomial ex.ansions Polynomial diffusions Stochastic correlation Jacobi process Stochastic volatility

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

Reply to “Beyond microbial carbon use efficiency”

引用

National Science Review 2024年第4期11卷 35-37页

作者： Feng Tao Johannes Lehmann Ying-Ping wang Lifen Jiang Bernhard Ahrens Kostiantyn Viatkin Stefano Manz.ni Benjamin z.Houlton Yuanyuan Huang x.aomeng Huang Yiqi Luo Department of Ecology and Evolutionary Biology Cornell University Soil and Crop Sciences Section School of Integrative Plant ScienceCornell University CSIRO Environment Max.Planck Institute for Biogeochemistry Department of Physical Geography and Bolin Centre for Climate Research Stockholm University Department of Global Development Cornell University Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Department of Earth System Science Ministry of Education Key Laboratory for Earth System Modelling Institute for Global Change Studies Tsinghua University

In their commentary, x.ao et al.[1]cautioned that the conclusions on the critical role of microbial carbon use efficiency (CUE) in global soil organic carbon (SOC) storage in the paper by Tao et al.[2] might be too *** claimed that Tao et al.’s study lacked mechanistic consideration of SOC formation and ex.luded important data *** et al. brought up important points,which can be largely reconciled with our findings by understanding the differences in ex.ressing processes in empirical studies and in models.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Finite element simulations on the mechanical properties of MHS materials

引用

Acta Mechanica Sinica 2007年第1期23卷 65-75页

作者： z. Y. Gao T. x. Yu D. Karagioz.va Department of Mechanical Engineering Hong Kong University of Science &Technology Clear Water Bay Kowloon Hong Kong China Institute of Mechanics Bulgarian Academy of Sciences Acad. G. Bonchev Street Block 4 Sofia 1113 Bulgaria

Finite element simulations are carried out to ex.mine the mechanical behavior of the metallic hollow sphere （MHS） material during their large plastic deformation and to estimate the energy absorbing capacity of these materials under uniax.al compression. A simplified model is proposed from ex.erimental observations to describe the connection between the neighboring spheres, which greatly improves the computation efficiency. The effects of the governing physical and geometrical parameters are evaluated; whilst a special attention is paid to the plateau stress, which is directly related to the energy absorbing capacity. Finally, the empirical functions of the relative material density are proposed for the elastic modulus, yield strength and plateau stress for FCC packing arrangement of hollow spheres, showing a good agreement with the ex.erimental results obtained in our previous study.

关键词： Cellular material Hollow sphere Large plastic deformation Numerical simulation FEM

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

Hydrogen Permeation and Diffusion in Amorphous Alloy Ni_(68)Cr7_Si_8B_(14)Fe_3 at Elevated Temperature

引用

Journal of Materials Science & Technology 1997年第5期13卷 443-445页

作者： Wu Q. x. J. Sun x. Hu z. National Key Lab. for RSA Institute of Metal Research Chinese Academy of Sciences Shenyang 110015 China

The behaviour of hydrogen permeation and diffusion in amorphous alloy Ni68Cr7Si8B14Fe3 hasbeen investigated by an ultrahigh vacuum gas permeation technique. A comparison ex.erimentwas carried out between the as-quenched and annealed States (400℃/2h) of the amorphousalloy. The results show that, for both states of the amorphous alloy in the temperature rangeof 200～350℃, the diffusivity and permeability of hydrogen are in agreement with Arrheniusrelationship, there does not ex.st H-trapping effect, and the activation energies of diffusion andpermeation almost keep the same.

关键词： Fe3 at Elevated Temperature Si Cr7Si8B Hydrogen Permeation and Diffusion in Amorphous Alloy Ni

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

Adaptive Robust Servo Control for Vertical Electric Stabiliz.tion System of Tank and Ex.erimental Validation

引用

Defence Technology（防务技术） 2024年第1期31卷 326-342页

作者： Darui Lin x.uye wang Yimin wang Guolai Yang School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094China

A tracking stability control problem for the vertical electric stabiliz.tion system of moving tank based on adaptive robust servo control is *** paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabiliz.tion system:model parameter uncertainty and uncertain ***,the vertical electric stabiliz.tion system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the ***,the dynamical equation in the form of state space is established by designing the angular tracking ***,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of ***,an adaptive robust servo control which can effectively handle the combined effects of complex.nonlinearity and uncertainty is *** feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the ex.erimental *** paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabiliz.tion system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through ex.eriment for the first time.

关键词： Adaptive robust servo control Ex.erimental validation Nonlinearity compensation System uncertainty Vertical electric stabiliz.tion system

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

Stability analysis of the simplest Takagi-Sugeno fuz.y control system using circle criterion

引用

Journal of Systems Engineering and Electronics 2007年第2期18卷 311-319页

作者： Lu Hongqian Huang x.anlin Gao x. z. Ban x.aojun Yin Hang Dept. of Control Theory and Engineering Harbin Inst. of Technology Harbin 150001 P. R. China Inst. of Intelligent Power Electronics Helsinki Univ. of Technology Espoo Finland

A frequency-domain-based sufficient condition is derived to guarantee the globally asymptotic stability of the simplest Takagi-Sugeno （T-S） fuz.y control system by using the circle criterion. The analysis is performed in the frequency domain, and hence the condition is of great significance when the frequency-response method, which is widely used in the linear control theory and practice, is employed to synthesiz. the simplest T-S fuz.y controller. Besides, this sufficient condition is featured by a graphical interpretation, which makes the condition straightforward to be used. Comparisons are drawn between the performance of the simplest T-S fuz.y controller and that of the linear compensator. Two numerical ex.mples are presented to demonstrate how this sufficient condition can be applied to both stable and unstable plants.

关键词： T-S fuz.y controller, Stability analysis Circle criterion Frequency response method.

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

Optimiz.tion Control of Multi-Mode Coupling All-Wheel Drive System for Hybrid Vehicle

引用

Chinese Journal of Mechanical Engineering 2024年第2期37卷 340-355页

作者： Lipeng z.ang z.jian wang Liandong wang Changan Ren School of Vehicle and Energy Yanshan UniversityQinhuangdao 066004China

The all-wheel drive(AWD)hybrid system is a research focus on high-performance new energy vehicles that can meet the demands of dynamic performance and passing *** optimiz.tion of the power and economy of hybrid vehicles becomes an issue.A unique multi-mode coupling(MMC)AWD hybrid system is presented to realiz. the distributed and centraliz.d driving of the front and rear ax.es to achieve vectored distribution and full utiliz.tion of the system power between the ax.es of *** on the parameters of the benchmarking model of a hybrid vehicle,the best model-predictive control-based energy management strategy is ***,the drive system model was built after the analysis of the MMC-AWD’s drive ***,three fundamental strategies were established to address power distribution adjustment and battery SOC maintenance when the SOC changed,which was followed by the design of a road driving force ***,the energy consumption rate in the average time domain was processed before designing the minimum fuel consumption controller based on the equivalent fuel consumption ***,the advantage of the MMC-AWD was confirmed by comparison with the dynamic performance and economy of the BYD Song PLUS *** findings indicate that,in comparison to the comparative hybrid system at road adhesion coefficients of 0.8 and 0.6,the MMC-AWD’s capacity to accelerate increases by 5.26%and 7.92%,*** the road adhesion coefficient is 0.8,0.6,and 0.4,the max.mum climbing ability increases by 14.22%,12.88%,and 4.55%,*** a result,the dynamic performance is greatly enhanced,and the fuel savings rate per 100 km of mileage reaches 12.06%,which is also very *** proposed control strategies for the new hybrid AWD vehicle can optimiz. the power and economy simultaneously.

关键词： Hybrid vehicle All-wheel drive Multi-mode coupling Energy management Model predictive control

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：