检索结果-南通市图书馆

Exchange bias for ferromagnetic/antiferromagnetic bilayers with the uniaxial anisotropy being misaligned with the exchange anisotropy

在线全文

学校读者我要写书评

暂无评论

science china(Physics,Mechanics & Astronomy) 2009年第12期52卷 1885-1892页

作者： BAI YuHao1 & YUN GuoHong1,2 1 college of Physical science and Technology,inner mongolia university,hohhot 010021,china 2 Key Laboratory of Physics and Chemistry of Functional Materials,college of Physics and Electronic Information,inner mongolia normal university,hohhot 010022,china 1. college of Physical science and Technology Inner Mongolia University Hohhot 010021 China 2. Key Laboratory of Physics and Chemistry of Functional Materials College of Physics and Electronic Information Inner Mongolia Normal University Hohhot 010022 China

Using the principle of minimal energy and S-W model,the exchange bias for ferromagnetic/antiferro-magnetic bilayers has been investigated when the uniaxial anisotropy is misaligned with the exchange anisotropy. According to the relation between the energy of the bilayer and the orientation of ferro-magnetic magnetization,it is found that the bilayer will be in the monostable state or bistable state when the external field is absent in the initial magnetization state. The monostable state or bistable state of the bilayer,which determines the angular dependence of exchange bias directly,is controlled by the competition between the exchange anisotropy and uniaxial anisotropy. When the applied field is parallel to the intrinsic easy axes and intrinsic hard axes,one of the switching fields of the hysteresis loop shows an abrupt change,while the other keep continuous by analyzing the magnetization reversal processes. Consequently,the exchange bias field and the coercivity will show a jump phenomenon. The numerical calculations indicate that both the magnitude and direction of the exchange anisotropy will significantly affect the angular dependence of exchange bias. The jump phenomenon of exchange bias is an intrinsic property of the bilayer,which is dependent on the interfacial exchange-coupling constant,the orientation of the exchange anisotropy,the thickness and uniaxial anisotropy constant of the ferromagnetic layer.

关键词： monostable state bistable state intrinstic easy axis intrinstic hard axis switching field

K-uniformly rotund spaces and k-uniformly smooth spaces

在线全文

学校读者我要写书评

暂无评论

Chinese science Bulletin 1998年第2期43卷 92-95页

作者： Suyalatu 1 and WU Congxin 2 1. Department of mathematics,inner mongolia normal university, Huhhot 010022, china 2. Department of mathematics, Harbin Institute of Technology, Harbin 150006, china Department of mathematics Inner Mongolia Normal University Huhhot China Department of mathematics Harbin Institute of Technology Harbin China

The conception of k_uniform smoothness (KUS) is introduced. It is the extension of the conception of uniform smoothness. It is proved that the k_uniform smoothness and Sullivan’s K_uniform rotundity (KUR) are the daul notions. X+* is a KUR space if and only if X is a KUS space, X+* is a KUS space if and only if X is a KUR space. If X is a KUS space, then X is a (K+1)US space. It is also proved that the KUS space includes the Nan’s k_strongly smooth space.

关键词： K_uniform smoothness K_uniform convexity.

Icosahedral quasicrystals solids with an elliptic hole under uniform heat flow

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2014年第5期23卷 397-403页

作者：李联和刘官厅 college of mathematics science Inner Mongolia Normal University college of Physical science and Technology Inner Mongolia University inner mongolia Key Laboratory of Nanoscience and Nanotechnology

The complex variable method for solving the two-dimensional thermal stress problem of icosahedral quasicrystals is stated. The closed-form solutions for icosahedral quasicrystals containing an elliptical hole subjected to a remote uniform heat flow are obtained. When the hole degenerates into a crack, the explicit solutions for the stress intensity factors is presented.

关键词： icosahedral quasicrystals thermal stress elliptic hole stress intensity factors

Traceability of Subsets in Cubic Graphs

在线全文

学校读者我要写书评

暂无评论

Systems science and Systems Engineering 1998年第3期8卷 123-124页

作者： A Yongga & Siqin Department of mathematics inner mongolia normal university Huhhot 010022, china

If X is a set of 20 vertices of a 3 connected cubic graph, then either every 13 subset of X is traceable or X is traceable in G .

关键词： cubic graph contraction traceable

Microscopic and Dynamic Rheological Characteristics of Crumb Rubber Modified Asphalt

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials science) 2010年第6期25卷 1022-1026页

作者：王岚 college of Civil Engineering Inner Mongolia University of Technology

A test for crumb rubber modified asphalt containing 20% crumb rubber particles（30 mesh） was performed using a scanning electron microscope（SEM）.The experimental results indicate that the crumb rubber particles are evenly distributed in the *** rate sweep and shear-temperature sweep tests on the crumb rubber modified asphalt at-20-80 ℃ using a dynamic shear rheology（DSR） instrument,were carried *** tests show that the complex modulus decreases with increasing temperature;at equivalent temperature,higher load frequencies lead to a larger complex modulus,and this value increasingly decreases as the temperature increases;the phase angle increases with temperature and decreases as the load frequency *** can be concluded that the rutting resistance limiting temperature of crumb rubber modified asphalt is 78 ℃,and the anti-fatigue limiting temperature is 16 ℃,which shows that the asphalt has preferable rutting resistance characteristics at high temperature,as well as anti-fatigue *** addition,the complex modulus master curve at different temperatures was plotted according to the time temperature equivalence principle,which allows the study of the dynamic state behavior of crumb rubber modified asphalt at a wide range of load frequency.

关键词： crumb rubber modified asphalt microcosmic characteristic rheology characteristic complex modulus phase angle

Comparative Analysis on Microstructure and Mechanical Properties between EBW and TANDEM Welding of 7A52 Aluminum Alloy Joint

在线全文

学校读者我要写书评

暂无评论

稀有金属材料与工程 2011年第S4期40卷 68-73页

作者： Zhai Xiwei1,2,Chen Furong1,2,Bi Liangyan1,2,Zhang Chuanchen3 1college of Materials science and Engineering,inner mongolia university of Technology,hohhot 010051,china2Key Laboratory of Materials Processing & Control Engineering of inner mongolia Autonomous Region,hohhot 010051,china3School of Materials science and Engineering,university of science and Technology Beijing,Beijing 100083,china inner mongolia Univ Technol Coll Mat Sci & Engn Hohhot 010051 Peoples R China Key Lab Mat Proc & Control Engn inner mongolia Au Hohhot 010051 Peoples R China Univ Sci & Technol Beijing Sch Mat Sci & Engn Beijing 100083 Peoples R China

The plates with 20mm thickness of 7A52 aluminum alloy were welded by electron beam welding and TANDEM welding with ER5356 filler,*** microstructure and mechanical properties of the joints were *** results showed that the microstructure of EBW metal was finer and tighter than TANDEM *** heat-affected zone of the EBW joint was narrower,its hardness was higher and the tensile strength improved obviously compared to TANDEM *** quality control of the EBW joint was made without abnormal porosity,inclusions and ***,the EBW joint of 7A52 aluminum alloy showed excellent performance.

关键词： 7A52 aluminum alloy electron beam welding TANDEM welding microstructure mechanical properties

Short cycle structures for graphs on surfaces and an open problem of Mohar and Thomassen

在线全文

学校读者我要写书评

暂无评论

science china mathematics 2006年第2期49卷 212-224页

作者： REN Han & DENG Mo Department of mathematics, East china normal university, Shanghai 200062, china college of mathematics & Information science, Northwest normal university, Lanzhou 730070, china 1. Department of mathematics East China Normal University Shanghai 200062 China 2. college of mathematics & Information science Northwest Normal University Lanzhou 730070 China

In this paper we investigate cycle base structures of a (weighted) graph and show that much information of short cycles is contained in an MCB (i.e., minimum cycle base). After setting up a Hall type theorem for base-transformation, we give a sufficient and necessary condition for a cycle base to be an MCB. Furthermore, we show that the structure of MCB in a (weighted)graph is unique. The property is also true for those having a longest length (although much work has been down in evaluating MCB, little is known for those having a longest length). We use those methods to find out some unknown properties for short cycles sharing particular properties in (unweighted) graphs. As applications, we determine the structures of short cycles in an embedded graph and show that there exist polynomially bounded algorithms in finding a shortest contractible cycle and a shortest two-sided cycle provided such cycles exist. Those answer an open problem of B. Mohar and C. Thomassen.

关键词： cycle base facial cycle graph embedding.

Study on the Changes of Grassland Vegetation Coverage in Yihewusu Gacha under Districting Rotational Grazing Way

在线全文

学校读者我要写书评

暂无评论

Study on the Changes of Grassland Vegetation Coverage in Yih...

Size effect of the elastic modulus of rectangular nanobeams:Surface elasticity effect

2012年环境污染与大众健康学术会议

作者： Hugejiletu 1 , SiRiGong 2 1 inner mongolia normal university college of Geographical science, hohhot,china, 010022 2 inner mongolia normal university college of Geographical science, hohhot,china, 010022

In the recently 20 years, grassland vegetation coverage change rapidly in inner mongolian Plateau, it both related to global climate change, and also closely related to is social and economic system in inner mongolia in the last 30 years. In this paper, Based on the relation between human and land theory as the guide, by using GIS and field survey method, with the Yihewusu Gacha of Abag Banner for research area, to take the four seasons pasture of districting rotational grazing as a unit, analyzes the changes of grassland vegetation coverage in the GaCha nearly 20 years. Results shows that [1]grassland degradation（grassland vegetation coverage decreased）;[2]the change of grassland vegetation coverage of districting at a quarter of rotational grazing is different, Vegetation coverage of summer pasture is highest, while the vegetation coverage of winter pasture is lowest. The analysis results showed that at present, "districting at a quarter of rotational grazing" one of more economical and effective method of protection natural grassland and restoration degraded grassland.

关键词： inner mongolia rotational grazing way grassland vegetation coverage

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第10期22卷 424-428页

作者：姚海燕云国宏范文亮 college of Ordos Inner Mongolia University inner mongolia Key Laboratory of Nanoscience and Nanotechnology college of Physical science and Technology Inner Mongolia University college of Physics and Electronic Information Inner Mongolia Normal University

The size-dependent elastic property of rectangular nanobeams （nanowires or nanoplates） induced by the surface elas- ticity effect is investigated by using a developed modified core-shell model. The effect of surface elasticity on the elastic modulus of nanobeams can be characterized by two surface related parameters, i.e., inhomogeneous degree constant and surface layer thickness. The analytical results show that the elastic modulus of the rectangular nanobeam exhibits a distinct size effect when its characteristic size reduces below 1 O0 nm. It is also found that the theoretical results calculated by a mod- ified core-shell model have more obvious advantages than those by other models （core-shell model and core-surface model） by comparing them with relevant experimental measurements and computational results, especially when the dimensions of nanostructures reduce to a few tens of nanometers.

关键词： size effects elastic modulus nanobeams surface elasticity