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《实验室研究与探索》2017,(1):62-64
为了扩展Fe-Ni合金纳米粒子的应用,采用直流电弧等离子体法在55%Ar+25%H_2+20%SiH_4的混合气氛中制备了SiO_2包覆Fe-Ni合金纳米粒子,并用其作为磁性粒子、油酸和十二烷基苯磺酸钠的混合液为表面活性剂、全氟碳油为基液制备了磁性液体。用黏度计和震动样品磁强计测试了制备的全氟碳油基磁性液体的黏度和磁性。结果表明,用SiO,包覆Fe-Ni合金纳米粒子作为磁性粒子制备的全氟碳油基磁性液体,在25℃,黏度为36.6~75.3 Pa·s;85℃,黏度为10.9~38.6 Pa·s;室温下饱和磁化强度为4.6~15.5 A·m~2/kg。 相似文献
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综述了国内外纳米磁性液体材料的发展现状。磁性液体材料是一种特殊的新型材料,是由磁性纳米微粒(一般要求小于10nm)均匀弥散于某种液体基液中所构成的稳定体系。同时具有磁性和流动性,因此具有许多独特的磁学,流动力学,光学和声学特性。系统介绍了目前纳米磁性液体材料根据纳米磁性液体材料中的铁磁性固体颗粒的不同的分类及纳米磁性液体材料的基本性质。最后综述介绍了纳米磁性液体依据其独有的特殊性能和其在化工环保、印刷制造、医疗卫生、仪器仪表、航天航空中典型应用。同时比较了国内外纳米磁性液体材料的发展状况。 相似文献
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根据磁性液体中磁性粒子的不同，分别介绍了铁氧体型、金属型和氮化铁型磁性液体的制备方法，并对磁性液体制备的发展方向进行展望。根据磁性液体性质，介绍了磁性液体在密封、精细研磨、润滑等工业以及其它诸多领域的应用。随着对磁性液体的性质和作用研究的深入，它的应用将更广泛。 相似文献
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利用磁天平和电子天平测量了不同电流和高度下磁性液体的表观密度。使用霍尔传感器测量不同电流下轴线上的磁场强度,通过origin软件对磁场强度拟合并求偏导,得到不同电流下轴线上的磁场梯度分布曲线。根据磁性液体的Bernoulli方程推导了磁性液体表观密度的表达式,磁性液体的表观密度由磁性液体的固有密度、磁化强度以及外加磁场及磁场梯度决定。无磁场作用时,磁性液体密度各处相等,说明磁性液体中的纳米磁性颗粒均匀分散在载液中;有外磁场作用时,随着外加磁场增强,磁场梯度也逐渐增强,导致磁性液体中悬浮的磁性颗粒移动到磁场及磁场梯度增强的位置,使得该处磁性液体的表观密度增加,理论结果与实验结果一致。 相似文献
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介绍了大连大学纳米磁性液体工作室的教师是如何以趣味纳米磁性液体选修课为主干,创新基金、创业大赛、科技作品、发表论文、考研等为枝叶树型结构的第二课堂,培养学生创新意识的实践与思考。 相似文献
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《实验室研究与探索》2016,(9):47-50
针对现有磁性液体视密度测量装置在实际测量过程中的繁琐及实验误差较大的弊端,设计了一台磁性液体悬浮性能测试智能装置,并以此通过计算机界面在线显示磁性液体悬浮性能的测试过程和规律曲线。结果表明,悬浮性能与磁场强弱、磁场梯度大小相关,磁场越强,梯度越大的液层,磁性液体悬浮性能越强。智能装置使纳米磁性液体悬浮性能的整个测试过程和测试方法更加简单直观,整体实验误差较小。通过对其影响因素所进行的理论分析,可为磁性液体在矿山选矿、物质分离等方面的潜在应用提供理论基础。 相似文献
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磁性纳米四氧化三铁颗粒的制备及应用进展 总被引：1，自引：0，他引：1
总结了磁性纳米Fe3O4粒子的共沉淀法、水热法、微乳液法、水解法、溶胶-凝胶法等,并讨论了磁性纳米Fe3O4粒子在磁性液体、生物医学、微波吸附材料等领域的应用.最后对纳米Fe3O4的研究前景进行了展望. 相似文献
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INTRODUCTION The specific morphologic properties of choroidal epithelium and the existence of a cerebrospinal fluid(CSF)pathway for drug distribution to the central nervous system(CNS)suggest that the choroid plexus-CSF route may be more significant than pre-viously thought for drug delivery to the brain(Ghersi-Egea and Strazielle,2001).There is limitedl d l d-n d information about the CSF pharmacokinetics of propofol in humans(Engdahl et al.,1998;Dawid-owicz et al.,2001a).Propofol… 相似文献
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Objective: The aim of this paper is to compare the propofol concentration in plasma and cerebrospinal fluid (CSF) in patients
scheduled for intracranial tumor removal and anaesthetized using propofol as part of a total intravenous anaesthesia technique.
Methods: Twenty-seven patients (ASA I–II) scheduled for elective intracranial tumor removal were studied. Anesthesia was induced
with 2 mg/kg propofol for 5 min and infused at 10 mg/(kg·h) for 5 min and then stopped. CSF and arterial blood were collected
simultaneously before infusion of propofol and at different time points after infusion of propofol according to bispectral
index (BIS) values. Concentrations of propofol in plasma and CSF were measured by HPLC with fluorescence detection. The correlation
coefficient and regression equation between plasma and CSF concentration of propofol were worked out by linear simple regression.
Results: The propofol CSF concentration that we measured was 1.46% of the plasma concentration. The coefficient of relation
between plasma and CSF concentration was 76.7%. Conclusions: The propofol CSF concentration was positively correlated with
and much lower than the plasma concentration. Discrepancies may result from high plasma protein binding of propofol, intracranial
pathology and sampling volume.
Project supported by Startup Foundation for Introducing Talent of Zhejiang University, China 相似文献
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An effective metric is developed on the background of light field in the plasma.Consistency with effective metric and Gordon‘s metric is under the ideal fluid approximation.The validity of effective metric is verified in the limit of non-relativistic limit.Finally the effective metric for plasma electrons is obtained. 相似文献
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吴怡芬 《喀什师范学院学报》2011,32(6):33-35
MHD方程组是来解释耀斑的复杂特性的等离子体流体动力学理论的重要模型.为此,主要通过太阳耀斑初期阶段的MHD模型来讨论耀斑的一些特征. 相似文献
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试验研究表明外加纵向磁场对电弧的电流密度、等离子流力有很大影响。本文对其变化规律及原因进行了分析和研究。 相似文献
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Chao-hua Tang Jia Liu Qing-yu Zhao Jun-min Zhang 《Journal of Zhejiang University. Science. B》2018,19(6):471-480
A pharmacokinetic comparison of gossypol isomers in cattle was made by investigating their transfer from ingested food to plasma and their degradation by rumen microbes. The gossypol isomers in whole cottonseed, plasma, and rumen fluid were determined by high-performance liquid chromatography (HPLC). The intakes of (+)- and (?)- gossypol by cows on three farms were about 5.6–8.5 and 3.8–5.9 g/(d·herd), respectively. The plasma gossypol concentrations increased as ingestion increased and ranged from 0.31 to 0.48 μg/ml for the (+) form and from 0.39 to 0.59 μg/ml for the (?) form. The (+) form was slightly predominant (58.8%–59.8%) in the gossypol ingested by the cows, whereas the (?) form predominated (54.6%–55.9%) in the plasma. An in vitro study showed that at 6 h, 67.4% and 85.7% of the (?)-gossypol were degraded in 500 and 1000 μg/g treatment groups, respectively, and these increased to 83.6% and 92.5%, respectively, at 12 h. The regularity of the degradation of (+)-gossypol was similar to that of (?)-gossypol. These results showed that (?)-gossypol may be more persistent than (+)-gossypol in plasma, and that the degradation of the gossypol isomers in the rumen is rapid and not enantioselective in cattle. 相似文献
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基于流体力学平衡方程 ,讨论了理想静态流体中声波的基本特性 ,给出了声波传播过程中流体介质中的速度、压强和密度分布形式。最后给声速的测量加了点注记 相似文献
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为了研究空芯光纤中氩气的放电特性,利用有限元软件 COMSOL Mutiphysics 基于流体模型对长为50mm 空芯光纤中的气体放电过程进行仿真,得到氩气放电过程中等离子体的主要参数分布,如电子密度、离子密度、电势、空间电荷密度、电场强度等。同时分析了气压对放电过程的影响,结果表明,气压对气体放电的影响主要体现在电子密度与阴极侧的电场强度上,随着气压的逐渐增大,阴极侧的电场强度也随之增加,阴极侧电子密度则保持不变,但在空芯光纤中央区域,电子密度的增大较为明显。 相似文献
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One dimensional electron density perturbation is derived by using the cold fluid equation,Possion‘s equation and the continuity equation.The perturbation is generated by a driving laser pulse propagating through a plasma,The upshifting of the frequency of a trailing pulse induced by density perturbation is studide by using optical metric.The results show that it is possible that the photon will gain energy from wht wakefield when assuming photon‘s number to be conserved.i.e..,thd photon will be accelerated. 相似文献