共查询到20条相似文献,搜索用时 93 毫秒
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以阳极氧化铝(AAO)为模板,利用磁控溅射法制备了Ni亚微米管阵列。通过X射线衍射仪(XRD)、原子力显微镜(AFM)、扫描电子显微镜(SEM)等手段对沉积态以及经过400℃退火保温不同时间制备的Ni亚微米管阵列的物相结构及微观形貌进行了表征。结果表明:磁控溅射法制备的Ni亚微米管阵列具有多晶的面心立方结构。随着退火时间的增加,Ni亚微米管逐渐增多,Ni衍射峰强度逐渐降低。经400℃退火3h后,获得结构完整、高度有序的Ni亚微米管阵列,Ni亚微米管的大小均匀,外径约为400nm,内径约为200nm,长度约为500nm。 相似文献
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Co88Ni12合金纳米线阵列的制备与磁性能表征 总被引:1,自引:0,他引:1
采用直流电化学沉积方法,在多孔阳极氧化铝模板的纳米级微孔内电沉积钴镍合金,制备出直径为30nm,长度为几个微米的准一维合金纳米线(阵列)材料;随后采用场发射扫描电子显微镜(FE-SEM),透射电子显微镜(TEM),X射线衍射仪(XRD),振动样品磁强计(VSM)对纳米线的形貌、结构及其磁性能进行了相关表征与测试.发现所制备的Co88Ni12合金纳米线表面光滑,粗细均一,具有较高的长径比;呈现密排六方结构(hcp),沿[100]择优取向生长,易磁化方向沿纳米线轴向方向. 相似文献
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亚微米高氯酸铵的制备及性能研究 总被引:1,自引:0,他引:1
采用LG-1型立式搅拌研磨机,以仲丁醇作为分散介质,通过控制研磨时间、转速、物料浓度等因素,制备了亚微米高氯酸铵(AP),并采用真空冷冻干燥技术对研磨浆料进行干燥得到产品。通过马尔文激光粒度仪、场发射扫描电子显微镜(FESEM)、X射线衍射仪(XRD)分别对制备的AP样品的粒度分布、颗粒大小和晶型进行表征,同时对制备的亚微米AP样品的摩擦感度、撞击感度以及热分解特性进行了表征。结果表明,所制备的AP样品平均粒径为460 nm;与普通工业级微米AP相比,亚微米AP样品的摩擦感度和撞击感度分别升高了20.0%和18.7%,高温分解峰峰温提前了60.1℃(升温速率10℃/min),表观活化能降低了27.3 k J/mol。同时,催化剂对亚微米AP的催化效果优于普通工业级微米AP。 相似文献
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段维忠 《中国材料科技与设备》2006,3(6):46-48,53
将石墨稳定地分散到润滑油中,可以有效改善润滑油的润滑性能。本文以天然石墨为原料、研磨获得亚微米级,考察了影响石墨粒子大小对其分散稳定性的影响;采用甲酸、硝酸以及硝化纤维素对石墨表面氧化处理,对比了表面改性后的石墨在润滑油中的分散情况,石墨在润滑油中较稳定分散的条件,经5%硝化纤维素在200℃-400℃范围内氧化的亚微米石墨的表面含有较多的羰基、碳氧键和醚基官能团,它们的存在改善了石墨粒子与润滑油的表面张力和表面化学作用,使其在润滑油中的分散稳定性最佳。 相似文献
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采用AAO模板7LAr+磨技术在Si基片上合成了大面积规则的六角纳米孔阵列,阵列六角晶格尺寸及纳米孔深度可由H3PO4扩孔时间、氧化电压、离子磨时间等工艺参数精确控制。孔间距、孔直径与工艺参数的关系为ID=15.8+2.17V和蹄0.905V+0.452TH-20,其中V为氧化电压,TH为H3PO4扩孔时间;孔深度则可被控制为:Y=27.59T-5.44X+21.76,X为AAO模板长径比,T为离子磨时间。该制备方法将可广泛应用于高效荧光发光器件、太阳能光伏器件、气体传感器件和THz受激辐射等光电子器件。 相似文献
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压缩变形制备亚微米晶钛合金的研究 总被引:3,自引:0,他引:3
对压缩变形制备超细晶钛合金的可行性进行了初步的实验研究。结果表明,低于725℃的压缩变形可以在TC11合金中获得亚微米晶组织;变形中α相发生再结晶,而同时β相经历一个析出和长大的过程;变形促进了β相的析出和长大,也改变了β析出相的形态。 相似文献
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利用显微粒子追踪测速系统(Micro-PTV)对四种不同粒径(2μm、1μm、0.71μm、0.52μm)的颗粒在纯水中的布朗运动进行了实验研究.使用波长为532nm的连续激光器、电子倍增CCD(EMCCD)相机以及放大倍率为63倍的显微物镜得到颗粒图像.对原始图像进行处理,借助于Video Spot Tracker软件获得相邻两帧图像中示踪颗粒的单步位移,在此基础上计算颗粒在纯水中的实验扩散系数,分别为0.191μm2/s,0.391μm2/s,0.579μm2/s及0.746μm2/s.将计算结果与采用Stokes-Einstein公式计算的无限大空间单个颗粒理论扩散系数进行了比对,偏差在10%以内,实验值略小.实验结果能够正确反映微米(μm)/亚微米颗粒布朗运动的特征. 相似文献
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Ni—Cu—P合金化学镀层制备及组织结构的研究 总被引:1,自引:0,他引:1
研究了Ni-Cu-P化学镀液主要成分、pH值及时间等工艺参数对化学沉积Ni-Cu-P合金镀层分及镀速的影响。通过选择适当的镀液成分及工艺参数,得到了Cu含量从0到56.18wt%的Ni-Cu-P合金镀层。利用X射线能谱术(EDS)和X射线衍射术(XRD)研究了镀液中硫酸铜浓度对Ni-Cu-P合金镀层成分及组织结构的影响。在硫酸铜浓度低于3g/l时,Ni-Cu-P合金镀层中P含量高于7.05wt%,合金底层是非晶态结构。 相似文献
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Docetaxel, a widely used anticancer agent, has sparingly low aqueous solubility, thus Tween 80 and ethanol need to be added into its formulation, probably resulting in the toxic effects. In this study, we aimed to utilize submicron lipid emulsions as a carrier of docetaxel to avoid these potential toxic vehicles. Preformulation study was performed for rational emulsions formulation design, including drug solubility, distribution between oil and water, and degradation kinetics. Supersaturated submicron lipid emulsion of docetaxel was prepared by temperature elevation method. Soya oil and Miglyol 812 can incorporate docetaxel up to 1.0% (drug to lipid ratio) and were used as the oil phase of emulsions. The optimal formulation of docetaxel is composed of 10% oil phase, 1.2% soybean lecithin, 0.3% Pluoronic F68, and 0.4 or 0.8 mg/mL docetaxel, with particle size in the nanometer range, entrapment efficiency more than 90%, and is physicochemically stable at 4 and 25 degrees C for 6 months. Animal studies showed that docetaxel emulsion has significantly higher area under the curve (AUC) and C(max) in rats compared to its micellar solution. The results suggested that the submicron lipid emulsion is a promising intravenous carrier for docetaxel in place of its present commercially available docetaxel micellar solution with potential toxic effects. 相似文献
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Ozdemir N Tuncel A Kang M Denkbaş EB 《Journal of nanoscience and nanotechnology》2006,6(9-10):2804-2810
In this study, a new thermosensitive material was proposed as a carrier for gene delivery. The thermosensitive submicron particles were synthesized by the dispersion copolymerization of N-isopropylacylamide (NIPA) with a relatively new, cationic comonomer, N-3-dimethylaminopropylmethacrylamide (DMAPM) with higher ionization ability with respect to the commonly used cationic comonomers. To achieve particle sizes smaller than 1 microm, suitable for gene delivery, the total monomer concentration in the dispersion copolymerization was kept at a sufficiently low level. The size of poly(NIPA-co-DMAPM) particles was determined as 454 nm, by AFM in dry state. The poly(NIPA-co-DMAPM) particles showed both temperature and pH sensitivity in the aqueous media.The plasmid DNA adsorption onto the thermosensitive cationic particles was investigated at different temperatures and pHs. The adsorbed amount of plasmid DNA onto the particles was significantly increased by the introduction of cationic comonomer. The equilibrium plasmid DNA adsorptions up to 13 mg/g dry particles were achieved at physiological pH. Approximately 36% w/w of adsorbed plasmid could be desorbed from the cationic nanolatex. The results of biocompatibility studies performed with mouse fibroblast cells showed the suitability of thermosensitive cationic particles for intended application. 相似文献
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Preparation and evaluation of proline-based chiral columns 总被引:2,自引:0,他引:2
Chiral stationary phases made of readily available proline peptides were prepared and evaluated for general chiral separation. With the proper structural elements, these columns demonstrated broad chiral selectivity. Among the 53 analytes tested, a tetraproline column resolved 31. The separations achieved for these analytes are comparable to those achieved on Whelk O2 column, while still inferior to those achieved on Daicel AD-H and OD-H columns. Number of proline units proves important for chiral recognition, because a control column made with a single proline unit is largely ineffective. 相似文献
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Ramona Strob Adrian Dobrowolski Damian Pieloth Gerhard Schaldach Helmut Wiggers Peter Walzel Markus Thommes 《Advanced Powder Technology》2018,29(12):2920-2927
The versatile use of submicron-sized particles (0.1–1?μm) requires new manufacturing methods. One possibility for the preparation of submicron-sized particles is spray drying. However, the generation of small droplets at a high production rate and the precipitation of submicron particles are quite challenging. In order to produce a sufficient amount of fine and uniform droplets, a two-fluid nozzle with internal mixing was combined with a cyclone droplet separator. The precipitation of particles was realized with an electrostatic precipitator. Considering the difficulty of electrostatic precipitation concerning explosion risks and to make it capable using organic solvents, the spray dryer was integrated in a pressure resistant vessel. Based on previous experiments, the now presented design is compact and the electrostatic precipitator is shortened. In addition, enhanced drying conditions ensured a controlled and reproducible preparation of submicron-sized particles. Thus, high separation efficiencies were shown. Spray-drying experiments were conducted with the model substance mannitol. With the cyclone droplet separator, a fine and uniform spray with a droplet size smaller 2?μm was produced. This robust atomizing technique is capable for high concentrations. For a 10?wt% mannitol solution, particles in the submicron range d50,3?=?0.7?μm were produced. 相似文献
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Bettina Lommel Willi HartmannAnnett Huebner Birgit KindlerJutta Steiner 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,655(1):44-46
The investigation of the distribution of the fusion-barrier height by heavy-ion collisions requires thin self-supporting targets. To increase the accuracy of the measurement the thickness and homogeneity has to be known as precisely as possible.We prepared the self-supporting nickel foils out of the isotopes 58Ni, 60Ni and 61Ni. The resulting targets were between 75 and 105 μg/cm² thick. The foils were produced on copper backing by electron-beam gun evaporation and by extracted ion-beam sputtering, both in high vacuum. To obtain self-supporting nickel foils the copper was removed by etching. We will discuss and compare both methods. 相似文献
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Nanocrystalline VC0.875 nonstoichiometric vanadium carbide powder has been prepared by high-energy milling. The crystal structure, microstructure, morphology, and particle size distribution of the starting and milled powders have been studied by X-ray diffraction, laser diffraction, and scanning electron microscopy. The particle size of the VC0.875 nanopowder has been calculated as a function of milling time in a model of the milling process. Comparison of experimental data and calculation results demonstrates that 10-h milling of vanadium carbide powder with an average particle size 6 μm yields nanopowder 40 to 80 nm in average particle size. 相似文献