检索结果-南通市图书馆

Interactions of ion acoustic multi-soliton and rogue wave with Bohm quantum potential in degenerate plasma

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

Chinese Physics B 2017年第9期26卷 301-309页

作者： M s Alam M G Hafez M R Talukder M Hossain Ali Department of Applied Mathematics University of RajshahiRajshahi-6205Bangladesh Plasma science and Technology Lab Department of Applied Physics and Electronic EngineeringUniversity of RajshahiRajshahi-6205Bangladesh Department of Mathematics Chittagong University of Engineering and TechnologyChittagong-4349Bangladesh

This work investigates the interactions among solitons and their consequences in the production of rogue waves in an unmagnetized plasmas composing non-relativistic as well as relativistic degenerate electrons and positrons, and inertial non-relativistic helium ions. The extended Poincare′–Lighthill–Kuo（PLK） method is employed to derive the two-sided Korteweg–de Vries（KdV） equations with their corresponding phase shifts. The nonlinear schrodinger equation（NLsE） is obtained from the modified Kd V（mKdV） equation, which allows one to study the properties of the rogue waves. It is found that the Fermi temperature and quantum mechanical effects become pronounced due to the quantum diffraction of electrons and positrons in the plasmas. The densities and temperatures of the helium ions, degenerate electrons and positrons, and quantum parameters strongly modify the electrostatic ion acoustic resonances and their corresponding phase shifts due to the interactions among solitons and produce rogue waves in the plasma.

关键词： wave-wave interaction rogue waves degenerate plasmas Bohm potential

Calibrating partial factors for Danish railway embankments using probabilistic analyses

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2014年第2期6卷 150-155页

作者： Michael R.Lodahl Kristian T.Brdbk Carsten s.srensen COWI A/s

High costs are connected with upgrading railway embankments throughout Denmark using the partial factors for geotechnical design calibrated for general application. One way to reduce the costs is reliability-based calibration of the partial factors to a reasonable safety level taking into account the specific design situations and uncertainties relevant to railway embankments. A reliability-based design has been investigated, resulting in an optimal partial factor for the considered subsoil. With a stochastic soil model to simulate the undrained shear strength of soft soil deposits, the partial factor is calibrated using asymptotic sampling for the reliability assessment. The calibration shows that the partial factor can be reduced significantly compared to the value specified in the Danish National Annex to Ds/EN 1997-1 （2007）, Eurocode 7.

关键词： Railway embankment Reliability index Partial factor stochastic soil modelling

在线全文

学校读者我要写书评

暂无评论

nEar 05

微型计算机 2005年第3期25卷 17-18,20-21页

作者： s＆CLabs

Ego systems简称EsI或Ego-sys，这问韩国公司一向以制造低价格、高性能的专业音频产品闻名于专业音频制作领域。其产品涵盖了专业录音卡、监听音箱和UsB声卡等。在大家的印象中，可能还记得MAYA录音卡、nEar 08监听音箱，以及MAYA EX系... 详细信息

Ego systems简称EsI或Ego-sys，这问韩国公司一向以制造低价格、高性能的专业音频产品闻名于专业音频制作领域。其产品涵盖了专业录音卡、监听音箱和UsB声卡等。在大家的印象中，可能还记得MAYA录音卡、nEar 08监听音箱，以及MAYA EX系列UsB声卡。其中，nEar08监听音箱曾在本刊2001年第18期报道过，那是它首次在国内媒体上亮相。经过四年多的市场检验，

关键词：有源监听音箱功率放大器扬声器音质 nEar 05

Characteristic Assessment of stabilized Polyacrylonitrile Nanowebs for the Production of Activated Carbon Nano-sorbents

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

Chinese Journal of Polymer science 2014年第4期32卷 449-457页

作者： s.Rafiei B.Noroozi sh.Arbab A.K.Haghi Department of Textile Engineering University of Guilan

Polyacrylonitrile （PAN） nanofibers with average diameter of 300 nm were produced by electro-spinning. The nanofibers were stabilized at different temperatures in the range of 180-270 ℃in several duration times and heating rates. Fourier transforms infrared （FTIR） spectroscopy, differential scanning calorimetry （DsC） and X-ray diffraction （XRD） analyzing techniques were employed to measure the extent of stabilization reaction. By all procedures, the ranges of temperature and duration time recommended were about 250-270 ℃ and 1-2 h, respectively. Increasing the activation temperature from 800 ℃ to 1200 ℃ caused porosity and pore volume development up to 60% and 0.532 cm3/g, respectively. Pore width of all samples was calculated to be about 0.7 nm confirming micro-pore structure of the produced PAN based activated carbon nanofibers. Comparing dye adsorption for different adsorbents including chitin and granular activated carbon （GAC） showed the highest efficiency for the produced activated carbon nanofibers （ACNFs）.

关键词： Polyacrylonitrile Electro-spinning stabilization Activated carbon nanofibers Adsorbent.

surface and Nonlocal Effects on the Thermoelastic Damping in Axisymmetric Vibration of Circular Graphene Nanoresonators

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica solida sinica 2022年第3期35卷 527-540页

作者： M.sheikhlou F.sadeghi s.Najafi H.Azimloo Department of Engineering sciences Faculty of Advanced TechnologiesUniversity of Mohaghegh ArdabiliNaminIran Mechanical Engineering Department Urmia UniversityUrmiaIran GuilAzma Inc.Anzali Free ZoneGuilanIran

In nanoresonators,thermoelastic damping(TED)is a primary energy dissipation *** a result,when designing nanoresonators,it is critical to limit this type of *** paper investigates the nonlocal TED of circular single-layered graphene sheet(sLGs)nanoresonators in axisymmetric out-of-plane vibration utilizing the generalized dual-phase-lag thermoelasticity *** nonlocal elasticity and Gurtin-Murdoch surface elasticity theories are employed to capture the small-scale and surface energy effects,*** incorporating these effects into the model,the non-classical equations of the coupled thermoelastic problem are first obtained and then an analytical expression is introduced to predict TED in circular ***,the results obtained herein are validated by those of the classical continuum theory which can be found in the open *** influences of the aspect ratio,surface elastic modulus,surface residual stress and nonlocal parameter on TED of circular sLGs nanoresonators are investigated using numerical *** calculated results show the significance of surface and nonlocal effects in nanoplate TED continuum modeling.

关键词： Thermoelastic damping Dual-phase-lag single-layered graphene sheet surface energy effects

ROLE OF α-PsEUDO-UNIVEX FUNCTIONs IN VECTOR VARIATIONAL-LIKE INEQUALITY PROBLEMs

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

Journal of systems science & Complexity 2007年第3期20卷 344-349页

作者： s. K. MIsHRA shouyang WANG K. K. LAI Department of Mathematics Statistics and Computer Science College of Basic Sciences and Humanities G. B. Pant University of Agriculture and Technology Pantnagar-263 145 India. Institute of systems science Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China. Department of Management sciences City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong China.

In this paper, we introduce a new class of generalized convex function, namely, a-pseudounivex function, by combining the concepts of pseudo-univex and α-invex functions. Further, we establish some relationships between vector variational-like inequality problems and vector optimization problems under the assumptions of α-pseudo-univex functions. Results obtained in this paper present a refinement and improvement of previously known results.

关键词： α-pseudo-univex functions vector optimization vector variational-like inequality problems.

Consequences of early life stress on the structure and function of the adult mouse retina

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第1期19卷 150-151页

作者： Juan s.Calanni Ruth E.Rosenstein Laboratory of Retinal Neurochemistry and Experimental Ophthalmology Department of Human BiochemistrySchool of Medicine/CEFyBOUniversity of Buenos Aires/CONICETBuenos AiresArgentina

Early-life stress(ELs)refers to a period of environmental/social deprivation,physica l,sexual or emotional abuse,neglect,severe and/or chronic trauma in the prenatal/early postnatal stage,which is closely related to many adverse psychiatric disorders later in life,such as depressive disorder,substance abuse,dysthymia,panic,anxiety,and suicidal behavior in adulthood(Waters and Gould,2022).

关键词： stress life Gould

Characterization of ion irradiated silicon surfaces ablated by laser-induced breakdown spectroscopy

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第8期27卷 505-510页

作者： T Iqbal M Abrar M B Tahir M seemab A Majid s Rafique Department of Physics Faculty of Sciences University of Gujrat Hafiz Hayat Campus Department of Physics Hazara University Mansehra Department of Physics University of Engineering and Technology (UET)Lahore Pakistan

Low energy metallic ions, generated by a Q-switched Nd：YAG laser （1064-nm wavelength, 10-mJ energy, 9-nm 12-ns-pulse width, 1011 W/cm2 intensity） irradiated on a silicon substrate to modify various properties, such as electrical, morphological, and structural modifications. Thomson parabola technique is used to calculate the energy of these metallic ions whereas the electrical conductivity is calculated with the help of Four-point probe. Interestingly circular tracks forming chain like damage trails are produced via these energetic ions which are carefully examined by optical microscopy. It is observed that excitation, ionization, and cascade collisions are responsible for surface modifications of irradiated samples. Four-point probe analysis revealed that the electrical conductivity of substrate has reduced with increasing trend of atomic number of irradiated metallic ions （A1, Ti, Cu, and Au）. The x-ray diffraction analysis elucidated the crystallographic changes leading to reduction of grain size of N-type silicon substrate, which is also associated with the metallic ions used. The decreasing trend of conductivity and grain size is due to thermal stresses, scattering effect, structural imperfections, and non-uniform conduction of energy absorbed by substrate atoms after the ion irradiation.

关键词： ablation Thomson parabola technique four-point probe

Roles of soil-structure interaction and damping in base-isolated structures built on numerous soil layers overlying a half-space

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2016年第2期15卷 387-400页

作者： C.s.Tsai C.I.Hsueh H.C.su Department of Civil Engineering Feng Chia University Graduate Institute of Civil & Hydraulic Engineering Feng Chia University Department of Water Resources Engineering and Conservation Feng Chia University

This study examines the roles of soil-structure interaction （ssI）, higher modes, and damping in a base-isolated structure built on multiple layers of soil overlying a half space. Closed-form solutions for the entire system, including a superstructure, seismic isolator, and numerous soil layers overlying a half-space, were obtained. The formulations obtained in this study simply in terms of well-known frequencies and mechanical impedance ratios can explicitly interpret the dynamic behavior of a base-isolated structure interacting with multiple soil layers overlying a half-space. The key factors influencing the performance of the isolation system are the damping ratio of the isolator and the ratio of the natural frequency of the fixed-base structure to that of the isolated structure by assuming that the superstructure moves as a rigid body. This study reveals that higher damping in the base isolator is unfavorable to higher mode responses that usually dominate the responses of the superstructure and that the damping mechanism plays an important role in transmitting energy in addition to absorbing energy. It is also concluded that it is possible to design a soft soil layer as an isolation system for isolating vibration energy.

关键词： base isolation seismic isolation soil-structure interaction closed- form solution higher-mode effects soilstratum passive control damping effects