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超细氧化锌粉末的研制 总被引:10,自引:1,他引:9
采用凝聚法制备超细氧化锌粉末,具有生产工艺简单、产品性能优良等特点。介绍了超细氧化锌粉末的制法,并采用正交试验确定了适宜的工艺条件。通过差热、X-衍射、电子显微镜等方法测试产品表明,所得的超细ZnO粉末优于普通的ZnO。 相似文献
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超细BaTiO3粉的液相合成技术研究 总被引:9,自引:2,他引:7
把快速混合技术运用于草酸盐沉淀法,制备了超细BaTiO3颗粒。运用XRD,TEM等测试手段,研究了制备超细BaTiO3粉末前驱体的液相合成工艺条件,过程规律及相应的表面处理技术。 相似文献
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超微细 Cu_2O 对 RDX/AP/HTPB 推进剂组分热分解特性影响的研究 总被引:5,自引:0,他引:5
通过氧化还原法在微乳液中合成了超微细的Cu2O(0.2μm),并用DTA研究了超细Cu2O、市购化学纯Cu2O(3μm)、YB、QC及它们的不同组合对RDX/AP/HTPB推进剂组分热分解特性的影响。实验结果表明:超细Cu2O能大幅度降低AP和RDX/AP(质量比1∶2)混合体系的分解活化能,其催化作用与市购Cu2O相比有较大的增强。与YB组合对AP和RDX/AP混合体系的催化有明显的协同效应,对RDX也有一定的催化作用。 相似文献
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分散染料应用于超细纤维的探讨肖学俊(苏州染料厂,苏州215007)StudyontheApplicationofDisperseDyesontheMicrofiberXiaoXuejun(SuzhouDyestuffPlant,Suzhou21500... 相似文献
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用自制的树脂热解炭用和SiO2纳米微粉作原料,用微波加热的方式合成了粒径在15mm左右,纯度达98.6wt%的超细SiC纳米微粉。用化学成分分析法,X射线衍射法,X射线小有散射法,透射电子显微镜等分子测试手段对得到的SiC纳米微粉进行了表征,研究并分析了其合成机理。 相似文献
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生产磁性材料的新原料—平炉尘及其提纯法 总被引:7,自引:0,他引:7
包头钢铁厂的平炉尘,以γ- Fe2O3 为主,含铁量高,颗粒微细。我们将平炉尘提纯转化分别得到了生产磁性材料的原料α- Fe2O3 和η- F2O3。再对γ- Fe2O3 进行分级,得到了超细γ- Fe2O3,并测定了它的粒径和X- 射线衍射分析。超细γ- Fe2O3 是制备超细尖晶石型铁酸盐的原料。本实验不仅为生产磁性材料找到了廉价的原料,又为自治区资源的综合利用及环境保护提供了新的途径。 相似文献
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Laura G. Shields Xueying Qin Stephen M. Toner Kimberly A. Prather 《Aerosol science and technology》2013,47(8):674-684
The significant and largely unregulated presence of ultrafine particles in the atmosphere is a growing environmental concern. Understanding the formation and sources of ambient ultrafine particles represents a major goal, but analyzing such small particles is a considerable analytical challenge. This study demonstrates how real-time measurements of particle size and chemistry, coupled with gas-phase measurements, can provide unique insight into the daily and seasonal variations of the sources and chemistry of ultrafine particles. Measurements of ambient ultrafine particles are compared from three different single particle techniques which provide high temporal resolution during the 2005 summer (August) and fall (November) seasons in Riverside, CA in conjunction with the Study of Organic Aerosols at Riverside (SOAR) field campaign. During both seasons, vehicle exhaust emissions strongly contributed to the ultrafine particle concentrations during the weekday morning rush hour periods. SMPS measurements during the summer season showed high ultrafine particle concentrations during the afternoons most likely formed by photochemical events. In this study, different sources (and hence chemistry) contributed to the particles during periods of high ultrafine particle concentrations. Therefore, it is important to obtain simultaneous information on ultrafine particle sources as well as concentrations and advance beyond relying just on ultrafine particle concentrations as a proxy in future studies on health effects. 相似文献
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A. Wiedensohler P. Aalto D. Covert J. Heintzenberg P. H. McMurry 《Aerosol science and technology》2013,47(2):95-109
Four different methods for measuring ultrafine particle size distributions in the 3–10-nm particle diameter range are compared and discussed. These methods all use an ultrafine condensation particle counter (TSI Inc. Model 3025 or its prototype) as the detector, but use different approaches to determine the size of the particles counted. Size classification was achieved using a Hauke Model VIE-06 differential mobility analyzer, a specially configured TSI Model 3040S diffusion battery, an ultrafine condensation particle counter with a variable condenser temperature, and an ultrafine condensation particle counter with a pulse height analyzer for signals produced by the optical detector. The response of these systems to ultrafine particles of known size and composition was studied during a workshop held in Lund, Sweden, during July 1991. After this workshop, measurements of ultrafine particles were made on the Swedish icebreaker Oden during the International Arctic Ocean Expedition 1991 (August 1, 1991 through October 7, 1991). In this article, the results of these laboratory and field measurements are discussed. The strengths and limitations of these measurement methods are emphasized. 相似文献
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超细HMX的表面能研究 总被引:2,自引:0,他引:2
用DCAT21型表面/界面张力仪测量了原料HMX(奥克托今,45μm~62μm)、超细HMX(0.2μm~1.7μm)和黏结剂FPM2602的接触角,并计算出它们的表面能。分析了HMX随粒径变化时其表面能的变化规律和黏结剂包覆超细HMX表面能的基本要求。结果表明,细化HMX表面能随粒径的减小有增加的趋势;黏结剂的表面能低于超细HMX的表面能,理论和实验均证明黏结剂FPM2602能包覆于超细HMX的表面。 相似文献
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Hee Dong Jang Kyun Young Park Cheong Song Choi 《Korean Journal of Chemical Engineering》1996,13(6):573-577
Experiments on the synthesis of ultrafine iron particles have been made for the control of particle size distribution using
the gas phase reduction of ferrous chloride with hydrogen. The previous studies were focused on the control of particle size
of ultrafine particles with the variation of the partial pressure of reactants, residence time of feed, and reaction temperature.
However, it is also very important to control the size distribution of ultrafine particles. In this study, the control of
particle size distribution was investigated from the standpoint of nucleation. The variation of evaporating condition at the
same evaporation rate of ferrous chloride, and of the temperature gradient of reactants between preheating zone and reaction
zone were adopted as experimental variables. Ultrafine iron particles having uniform size distribution could be produced under
the control of evaporating condition such as the change of the surface area at constant evaporating temperature. As the temperature
gradient decreased, particle size distribution became uniform and average particle sizes were also decreased. 相似文献
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通过超声法制备了超细涂料色浆,并将其应用到阴极电泳漆中。考察了超细化前后涂料色浆的平均粒径、Zeta电位的变化,比较分析了超细涂料色浆与普通涂料色浆用于阴极电泳漆时漆液稳定性、漆膜沉积量、颜色深度、外观的区别。实验结果表明:超细涂料色浆的平均粒径仅为196 nm,Zeta电位为30 mV且分布均匀。用超细涂料色浆配制的电泳漆液具有较高的离心稳定性。相比于含普通涂料色浆的阴极电泳漆,含有超细涂料色浆的阴极电泳漆的漆膜的电沉积量稍高,而且更加均匀、平整、细腻。 相似文献
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Thermophoresis of ultrafine particles in a turbulent pipe flow was studied using high-temperature and high-concentration polydisperse ultrafine particles. Experimental conditions were designed to simulate particle behaviour in an automobile exhaust pipe, with a particular focus on establishing similar particle residence time. From the experimental results, thermophoresis was found to be a dominant mechanism for ultrafine particle deposition in the turbulent pipe flow. A previous thermophoretic deposition model was found to be inadequate with respect to estimating the results of the experimental conditions. In this study, the experimental data and the computational analysis results reflect the necessity of establishing a new formula for thermophoretic deposition for high-concentration polydisperse ultrafine particles in a pipe flow. 相似文献
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A model is presented to describe the collection of ultrafine particles by the UNC passive aerosol sampler. In this model, particle deposition velocity is calculated as a function of particle size, shape and other properties, as well as a function of sampler geometry. To validate the model, deposition velocities were measured for ultrafine particles between 15 and 90 nm in diameter. Passive aerosol samplers were placed in a 1 m 3 test chamber and exposed to an ultrafine aerosol of ammonium fluorescein. SEM images of particles collected by the samplers were taken at 125 kX magnification. Experimental values of deposition velocity were then determined using data from these images and from concurrent measurements of particle concentration and size distribution taken with an SMPS. Deposition velocities from the model and from the experiments were compared and found to agree well. These results suggest that the deposition velocity model presented here can be used to extend the use of the UNC passive aerosol sampler into the ultrafine particle size region. 相似文献