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101.
We propose a six-parameter exponential-type potential (SPEP),which has been shown to be a shapeinvariant potential with a translation of parameters.For this reducible potential,the exact energy levels are obtained by using the supersymmetric shape invariance technique.Choosing appropriate parameters,four classes of exponential-type potentials and their exact energy spectra are reduced from the SPEP and a general energy level formula,respectively.Each class shows the identity except for the different definitions of parameters. 相似文献
102.
Molecular dynamics simulations of nanoimprint lithography (NIL) were performed to investigate the effects of three critical process parameters in NIL: stamp shape, adhesive energy between the stamp and polymer film, and imprint temperature. The proposed simulation model of the NIL process consists of an amorphous SiO2 stamp with a line pattern, an amorphous poly(methylmethacrylate) film, and a Si substrate under the periodic boundary condition in the horizontal direction to simulate a real NIL process imprinting periodical line patterns. The behavior of polymer deformation and the effects of adhesion on pattern transfer were investigated by observing the deformation process, calculating the imprint and separation forces, and analyzing the density and stress distribution inside the polymer film. In addition, their dependency on the process parameters is also discussed with reference to the changes in pattern shape, adhesive energy between the stamp and polymer atoms, and imprint temperature of the polymer film. During the imprint process, the rectangular pattern shows inferior cavity filling and higher stress concentration compared to trapezoidal and triangular patterns because it requires much larger flow and deformation of the polymer film. Low imprint temperature also produces high stress concentration and large imprint force due to the lower fluidity of polymer film. In the separation process, the rectangular pattern generates the largest separation force and causes the most serious defects of the transferred pattern and even the polymer film, while the triangular pattern shows the most satisfactory pattern transfer. In addition, the adhesive energy between the stamp and the polymer film also strongly influences the adhesion between the stamp and the polymer film. Low adhesive energy reduces the separation force of the stamp and transferred pattern defects, and therefore enhances the quality of pattern transfer. 相似文献
103.
Zhigang Wu 《固体物理学:研究快报》2015,9(5):317-320
We report the direct experimental observations of the glassy behaviour in Ni–Co–Mn–Sn ferromagnetic shape memory alloys by doping sufficient substitutional point defect Co into the Ni sites (9 at%). The results showed that high level of Co doping had caused the complete suppression of the martensitic transformation and introduction of a strain glass transition in Ni–Co–Mn–Sn alloys. The strain glass transition was definitively characterized by the dynamic mechanical anomalies following the Vogel–Fulcher relationship and the signature nonergodicity of the frozen glass using a zero‐field‐cooled/field‐cooled heating measurement of static strain. The findings clarified the cause of vanishing of the martensitic transformation in Ni–Co–Mn–Sn alloy with high Co doping levels and the generality of glassy state in Ni–Mn based ferromagnetic shape memory alloys with high level of foreign elements doping. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
104.
A. Annadurai S. Jayakumar M. Manivel Raja R. Gopalan V. Chandrasekaran 《Journal of magnetism and magnetic materials》2009,321(6):630-634
Polycrystalline Ni-Mn-Ga thin films were deposited by the d.c. magnetron sputtering on well-cleaned substrates of Si(1 0 0) and glass at a constant sputtering power of 36 W. We report the influence of sputtering pressure on the composition, structure and magnetic properties of the sputtered thin films. These films display ferromagnetic behaviour only after annealing at an elevated temperature and a maximum saturation magnetization of 335 emu/cc was obtained for the films investigated. Evolution of martensitic microstructure was observed in the annealed thin films with the increase of sputtering pressure. The thermo-magnetic curves exhibited only magnetic transition in the temperature range of 339-374 K. The thin film deposited at high sputtering pressure of 0.025 mbar was found to be ordered L21 austenitic phase. 相似文献
105.
In this paper, we consider four common types of ruin probabilities for a discrete‐time multivariate risk model, where the insurer is assumed to be exposed to a vector of net losses resulting from a number of business lines over each period. By assuming a large initial capital for the risk model and regularly varying distributions for the net losses, we establish some interesting asymptotic estimates for ruin probabilities in terms of the upper tail dependence function of the net loss vector. Our results insightfully characterize how the dependence structure among the individual net losses affect the ruin probabilities in an asymptotic sense, and more importantly, from our main results, explicit asymptotic estimates for those ruin probabilities can be obtained via specifying a copula for the net loss vectors. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
106.
金属纳米结构对光谱响应及折射率灵敏度的影响 总被引:1,自引:0,他引:1
推导了任意形状金属纳米结构对复杂环境折射率的局域表面等离子体共振(LSPR)光谱响应的解析解,给出了体折射率和局部折射率灵敏度公式,并进行了详细的理论分析和数值验证。结果表明,金属纳米结构的光谱响应与被分析物厚度呈指数增长关系,并与被分析物的折射率、敏感层厚度、金属纳米结构的材料和形状等因素有关。被分析物折射率越高,光谱响应越大。敏感层越厚,局部折射率灵敏度越差。同时,尖锐的金属纳米结构形状可以获得更大的体折射率灵敏度。对金属纳米结构光谱响应及折射率灵敏度的研究对制作高灵敏度LSPR传感器具有重要的指导意义。 相似文献
107.
108.
Zhi‐Jian Zhang Zhe Zheng Liang‐Liang Qiang Zhun Ma Shi‐Xiang Xie Bo Peng Wei Huang Wei Wei 《Macromolecular rapid communications》2006,27(16):1317-1322
Summary: Novel non‐covalently connected water‐soluble nanoparticles that contain poly(fluorene‐co‐phenylene) with hydroxy‐capped alkoxy side chains (PF3BOH) and poly(acrylic acid) (PAA) have been obtained and characterized. With different proportions of PF3BOH and PAA, the shape and size of the nanoparticles can be regulated. The nanoparticles are quite stable in water with no precipitate being observed after weeks. Transmission electron microscopy and dynamic laser light scattering are used to confirm the morphology of the PF3BOH/PAA nanoparticles. Their optical properties have been investigated and show similar optoelectronic properties to a PF3BOH solid film although they do not undergo aggregation.
109.
结合国内外最新研究成果,综述了压电材料?电/磁流变液?形状记忆合金等智能材料的基本性能?工作原理及其在土木工程结构振动控制中的应用研究概况,并对研究及应用中存在的问题作了探讨. 相似文献
110.
某天气雷达站塔楼结构时程分析 总被引:5,自引:0,他引:5
运用通用有限元程序ANSYS对某天气雷达站塔楼结构进行了自振特性分析及地震载荷作用下的时程分析,通过计算得出了雷达站塔楼的前20阶频率、振型,并进一步计算了在地震作用下时程分析的位移及内力,结果表明该结构具有很大的抗侧刚度,且沿高度分布均匀,自振频率满足结构使用要求,验证了结构设计的可靠性,为结构设计提供了可靠的参考数据. 相似文献