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Tracking moving magnetic features in the photosphere

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Science China(Physics,Mechanics & Astronomy) 2009年第11期52卷 1737-1748页

作者： bCHNER jrg Max-Planck-Institut fr Sonnensystemforschung

This research aims for an objective identification, tracking, and a statistical analysis of the Moving Magnetic Features (MMFs) around sunspots using SOHO/MDI high-resolution magnetograms. To this end, we develop a computerized tracking program and study the motion and magnetism of the outflows of MMFs around 26 sunspots. Our method locates 4-27 MMFs per hour, with higher counts for large sunspots. We differentiate MMFs into type α that have a polarity opposite to the parent sunspots, and type β that share the sunspot's polarity. These sunspots' MMF subsets exhibit a wide range of central tendencies which have distinctive correlations with the sunspots. In general, α-MMFs emerge farther from the sunspot, carry less flux, and move faster than β-MMFs. The typical α/β-MMFs emerge at 2.2 - 8.1/0.1 - 3.2 Mm outside the penumbra limb, with lifetimes of 1.1 - 3.1/1.3 - 2.0 h. They are 1.1 - 6.6/1.4 - 3.6 Mm2 in area and carry 1.4 - 12.5/4.8 - 11.4 ×1018 Mx of flux. They travel a distance of 2.7 - 5.9/2.8 - 3.6 Mm with the speed of 0.5 - 0.9/0.4 - 0.7 km/s. Compared to the α-MMFs produced by large sunspots, those of small spots are smaller. They emerge closer to sunspot, move farther, live longer, and carry less flux. β-MMFs show much less correlation with the sunspots. The flux outflow carried by the MMFs ranges from 0.2 to 8.3 × 1019Mx· h-1 and does not show obvious correlation with the sunspots' evolution. The frequency distributions of the MMFs' distance traveled, area, and flux are exponential. This suggests the existence of numerous small, weak, and short-timescale magnetic objects which might contribute to the sunspot flux outflow.

关键词： sun activity magnetic fields photosphere sunspots moat moving magnetic features

Laser induced photo-detachment of O2 in DC discharge

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Plasma Science and Technology 2018年第7期20卷 98-105页

作者： j r legorreta j l patiNo f b yousif Centro de Investigacion en Ciencias Universidad Autonoma del Estado de Morelos.Av.UniversidadNo.1001 Col.Chamilpa Cuemavaca MorelosMexico

Determination of the negative ion number density of O2 and O in a DC discharge of oxygen plasma was made employing Langmuir probe in conjunction with eclipse laser photo- detachment technique. The temporal evolution of the extra electrons resulting from the photo- detachment of O2- and O- were used to evaluate the negative ion number density. The ratio of O2 number density to O varied from 0.03 to 0.22. Number density of both O~ and O increased with increasing power and decreased as the pressure was increased. Electron number density was evaluated from the electron energy distribution function （EEDF） using the I-V recorded characteristic curves. Electron temperature between 2 and 2.7 eV were obtained. Influence of the 02（al△g） metastable state is discussed.

关键词： electronegative plasma electron temperature Langmuir probe negative ion number density

Impact of La^(3+)substitution on electrical,magnetic,dielectric and optical properties of Ni_(0.7)Cu_(0.1)Zn_(0.2)LaxFe_(2-x)O_(4)(0

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作者： (英)j.b.伯里

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journal of Rare Earths 2023年第5期41卷 740-746,I0004页

作者： b.b.Patil A.D.Pawar S.S.barate j.S.Ghodake j.b.Thorat T.j.Shinde P.G.Department of Physics Smt.KRP Kanya MahavidyalayaIslampurMS415409India Department of Physics Shivaji UniversityKolhapurMS416004India Departments of Physics PDVP MahavidyalayaMahavidyalayaTasgaonMS416312India Department of Physics Sadguru Gadage Maharaj CollegeKaradMS415110

The oxalate co-precipitation method was used to synthesize the La3+substituted Ni-Cu-Zn(La-NCZ)nanoferrites having chemical composition Ni_(0.7)Cu_(0.1)Zn_(0.2)LaxFe_(2-x)O_(4)(x=0.015,0.025 and 0.035).DC resistivity study of nanoferrites shows both the conducting and semiconducting *** room temperature DC electrical resistivity of Ni-Cu-Zn(NCZ)nanoferrites decreases,whereas Curie temperature increases with increasing La^(3+)*** the temperature range of 30-170℃nanoferrites show p-type semiconducting behavior except x=0.015;thereafter,they show n-type *** frequency dispersive initial permeability(μi)associated with its real and imaginary(μ’andμ")parts are attributed to the domain wall movement and magnetic spin ***μi,u’andμ"of La-NCZ nanoferrites are higher than those of pure NCZ *** constant(ε’),dielectric loss(ε")and AC resistivity(ρAC)of La-NCZ nanoferrites show normal dielectric *** is found thatε’of NCZ nanoferrites decreases with the increasing content of La3+*** bandgap energy of La-NCZ nanoferrites is achieved in the range 1.36-1.70 eV confirming the semiconducting nature of materials.

关键词： Ni-Cu-La-Zn nanoferrites DC electrical Resistivity Permeability Dielectric properties bandgap energy Rare earths

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海市蜃楼中的资本主义

马克思主义与现实 2009年第5期61卷 185-190页

作者： R.约克 b.克拉克 j.b.福斯特夏泳美国俄勒冈大学社会学系美国北卡罗来纳州立大学社会学系江西外语外贸职业学院

文章围绕气候经济问题,深入评价了目前国际上流行的各家经济学观点,认为传统经济学无力应对甚至认清全球生态危机的实质,在发展定位上毫无可持续性。主流经济学通过对未来赋予高的贴现值,否定了后代人生存和发展的权利;有关碳税应该定... 详细信息

文章围绕气候经济问题,深入评价了目前国际上流行的各家经济学观点,认为传统经济学无力应对甚至认清全球生态危机的实质,在发展定位上毫无可持续性。主流经济学通过对未来赋予高的贴现值,否定了后代人生存和发展的权利;有关碳税应该定在什么水平的争议,并未能抓住气候变化问题的症结;他们提出的"b计划"实质上是唯科学主义的。解决气候变化问题,必须像马克思那样从资本主义经济制度入手,抛弃新自由主义意识形态,积极反对"利润和生产之神"的忠诚信使,即我们时代的显赫经济学家。

关键词：气候变化经济学家海市蜃楼新自由主义

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上海连环画精品百种中外少儿故事逃出盗宣窝

2002年

作者：（德）j.b.布劳恩原张光炎改编

故事发生在“九一八”事变后的沈阳。

ISBN: (纸本)7532229033

故事发生在“九一八”事变后的沈阳。

关键词：文化、科学、教育、体育教育学前教育、幼儿教育

来源：汇雅图书（南通市图书馆... 评论

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汇雅图书（南通市图书馆）

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英语学习指南

英语学习指南

作者： j.b.·希顿(j.b. Heaton) j.P.·斯托克斯(j.P. Stocks)

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药物作用的化学基础

药物作用的化学基础

Repercussion of Hall effect and nonlinear radiation on Couette-Poiseuille flow of Casson-Williamson fluid through upright microchannel

1982年

作者： (英)j.b.斯坦莱克

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Applied Mathematics and Mechanics(English Edition) 2022年第12期43卷 1951-1964页

作者： b.j.GIREESHA L.ANITHA Department of Post Graduation Studies and Research in Mathematics Kuvempu UniversityShankaraghatta 577451India Department of Mathematics Adichunchanagiri Institute of TechnologyChikkamagaluru 577102India

The main aim of the present work is to investigate the flow and heat transport properties of non-Newtonian Casson-Williamson fluid through an upright microchannel along with entropy generation analysis,and explore the effects of convective boundary conditions,Couette-Poiseuille flow,and nonlinear *** movement of liquid is scrutinized with the Hall effect and exponential heat *** rheological characteristics of the Casson-Williamson fluid model are also *** considering the desirable similarity variables,the equations of motion are reduced to nonlinear ordinary differential *** Runge-Kutta-Fehlberg fourth-fifth order method along with the shooting method is adopted to solve these dimensionless *** detailed investigation is pictorially displayed to show the influence of effective parameters on the entropy generation and the bejan *** of the major tasks of the exploration is to compare the Casson fluid and the Williamson *** results show that the rate of heat transfer in the Casson fluid is more remarkable than that in the Williamson fluid.

关键词： entropy generation bejan number convective boundary condition Hall effect nonlinear radiation exponential heat source