共查询到20条相似文献,搜索用时 221 毫秒
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针对磁性液体薄膜在MEMS加工领域作为光刻掩膜的应用,为获得磁性液体薄膜在磁场作用下的微形变规律,设计了一套磁场下磁性液体薄膜微形变的磁控测试实验台,并从磁场强度、磁性液体种类、磁性液体中磁性颗粒质量分数、磁性液体量和磁场梯度五个方面对其微形变特性进行实验研究。利用磁性液体薄膜形变高度和半径两个参数对其微形变效果进行了评价,实验结果表明:磁性液体薄膜凸起高度与磁场强度平方呈正比;基载液密度低的磁性液体凸起高度大;烃基磁性液体在磁性颗粒质量分数为25%时形变效果最好;磁性液体在达到一定的体积后其凸起高度几乎不变;磁场梯度越大,其凸起高度越明显,形变图形越佳。 相似文献
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采用固相反应法制备了 GdBaCo1.8Fe0.2O5.5–δ块体,通过 XRD 及 PPMS 测量表征了样品的结构及磁性特征。研究结果表明,样品为单相正交层状钙钛矿结构,样品磁矩和测量历史有关,呈现团簇玻璃行为。样品在反铁磁奈尔温度以下存在变磁性转变行为,转变磁场区域较宽,转变磁场强度随着温度升高而降低。这些磁性行为被认为和掺铁样品中的相分离相关。 相似文献
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双光镊测量胶体微粒间相互作用势 总被引:5,自引:2,他引:3
分析了两个存在相互作用势的胶体微粒的布朗运动,讨论了通过微粒布朗运动的显微观测来测量胶体微粒间相互作用势的实验方法。将双光镊系统与同步斩光器相结合,建立了相应的测量系统。对1μm直径的聚苯乙烯球悬浮液中两个小球之间的静电相互作用势进行了实验研究。实验结果和DLVO(Derjagin-Landau-Verwey-Overbeek)理论符合较好,为DLVO理论提供了直接的微观实验依据。对决定实验精度和效率的一些实验因素,包括测量过程中光镊的开关切换时间、光镊打开和关闭的持续时间、样品离样品池底面高度和实验测量区间划分精度等进行了具体讨论。所建立的实验装置和方法可用于测量不同类型胶体粒子间的相互作用势,这为深入研究决定分散体系宏观性质的微观基础提供了一种有效的手段。 相似文献
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文章主要针对用落球法变温粘滞系数实验仪测量液体的粘滞系数实验进行了误差分析。总结了影响系统测量精度的主要误差来源于以下八个方面:油筒未放置水平;液体温度与水温不一致;液面产生漩涡;小球下落偏离轴线方向;小球刚进入液体时为非匀速运动;小球作匀速运动对油筒刻线位置判断不准确;秒表计时;小球表面污染等。 相似文献
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利用磁流体替代光纤布喇格光栅(FBG)的部分二氧化硅包层,制作了一种磁流体封装薄包层FBG结构的磁场传感器,研究了传感器对磁场和温度的响应特性。结果表明,在5.0~20.0mT的磁场范围内,传感器的波长灵敏度和功率灵敏度分别为34.9pm/mT和-1.063dBm/mT,波长线性响应度达到了99.2%。封装工艺未改变FBG波长随温度线性变化的特性,但受磁流体磁光效应影响,其温度灵敏度减小到9.2pm/℃。该传感器可实现磁场测量中的温度补偿,方法简单、易于实现。 相似文献
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为了提高磁光成像增强效果,采用量子多元宇宙算法。首先铁磁材料施加磁场时,磁场的N、S级产生的光强差别性使得磁光成像区域的亮度由暗到明逐渐变化,焊缝磁光成像的像素灰度值与焊缝亮度成正比;接着引导滤波减少磁畴区域对磁光成像的影响,atctan函数对磁光成像区域增强;最后给出了算法流程。实验显示磁感应强度变化随着交变电压的增加而变大,霍尔探头离焊缝中心越远,则磁感应强度越小,磁感应强度在焊缝中心呈现对称分布,最小值在焊缝中心处,即磁场N级、S级交接处;磁畴特性随低频交流电压增加表现越明显;本文算法使得磁光成像增强效果清晰,评价指标较优。 相似文献
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Andrew G. Gillies Jonghun Kwak Ronald S. Fearing 《Advanced functional materials》2013,23(26):3256-3261
Particle capture and release using controllable adhesion is of growing interest in many fields including reusable adhesives, solar panel cleaning, micro‐manipulation and robot locomotion where current methods of particle management are not sufficient. Here controllable adhesion to glass spheres with a new magnetically actuated synthetic gecko adhesive made from a magnetoelastomer composite is demonstrated. Adhesion is controlled by changing the effective elastic modulus of the surface through actuation of micro surface features with an external magnetic field. A compliant mechanics and magnetic torque analysis explains this general principle and generalizes the results for various geometries. Results show sphere pull‐off forces can be increased 10‐fold by changing the ridge orientation via the external magnetic field, and that the effective elastic modulus can be changed from 65 kPa to 1.5 MPa. Particle transport and release of 500‐ and 1000‐micrometer glass spheres is also demonstrated. 相似文献
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Multicomponent hybrid nanostructures that contain two or more nanometer‐scale components have attracted much attention recently owing to the synergistic properties induced by interactions between these different nanometer‐scale objects. Herein, we give an overview of the efforts to synthesize multicomponent nanoparticles with at least one component being magnetic, and focus on our recent developments. The syntheses are based on heterogeneous nucleation and growth of a second and third component onto seed nanoparticles. These multicomponent nanoparticles show interesting magnetic, magneto‐optical, plasmonic, and semiconducting properties that can be modulated by interfacial interactions between different nanocomponents. This opens up a new avenue to advanced multifunctional nanomaterials for device concepts and applications. 相似文献
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Sebastien Couet Manisha Bisht Maarten Trekels Mariela Menghini Claire Petermann Margriet J. Van Bael Jean‐Pierre Locquet Rudolf Rüffer André Vantomme Kristiaan Temst 《Advanced functional materials》2014,24(1):71-76
Composite multiferroics are a new class of material where magneto‐electric coupling is achieved by creating an interface between a ferromagnetic and a ferroelectric compound. The challenge of understanding the chemical and magnetic properties of such interface is a key to achieve good magneto‐electric coupling. The unique possibilities offered by isotope sensitive techniques are used to selectively investigate the interface's chemistry and magnetism in Fe/BaTiO3 and Fe/LiNbO3 systems during the application of an electric field. With a large enough electric field, a strong oxidation of Fe is triggered, which creates a magnetically dead interface. This leads to an irreversible decrease of the magneto‐electric coupling properties. Material parameters are identified that determine under which electric field the interface may be modified. The results are confirmed on the two systems and are expected to be widespread in this new class of hybrid material. 相似文献
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乙醇热还原法制备空心镍球研究 总被引:1,自引:0,他引:1
以Ni(Ac)2·4H2O为原料,无水乙醇为溶剂和还原剂,利用乙醇热还原法,在不锈钢反应釜中,于230℃反应24h,制备了空心镍球(样品)。并用TEM、SEM和XRD研究其微结构及磁性能。结果表明:该球为单相的面心立方结构,含有约60%空心镍球结构及一些环状、半环状和半球状结构,直径在400~700nm;磁矫顽力为962.9A/m。最后探讨了空心镍球的形成机理。 相似文献
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为了提高磁光成像增强的效果,提出动态宇宙算法.首先建立宇宙空间模型,宇宙连接距离随着层的变化而动态改变;接着宇宙间信息交流、位置更新涉及到不同层、相同层;然后基于灰度因子对磁光成像对比度提高,通过灰度积分投影定位获得磁畴位置,总变差模型对磁畴纹理去除;最后给出了算法流程.实验仿真显示交变电压越大产生的磁感应强度越强,漏... 相似文献