共查询到20条相似文献,搜索用时 93 毫秒
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低温超强碱法制备引入有机添加剂的纳米四方多晶氧化锆粉体及其性能 总被引:1,自引:1,他引:0
采用引入有机添加剂的低温超强碱法,控制适当的工艺条件,得到了室温稳定的纳米四方/立方多晶氧化锆粉体。采用X射线荧光光谱、X射线衍射、透射电镜、粒度分析仪等手段对粉体性能进行了表征。实验结果表明:该粉体在室温和小于873K热处理时,均以稳定的立方或四方相存在,粉体粒径为9nm左右。在1123K处理的粉体分散性好、粒度小、粒度分布较窄,粉体颗粒的平均粒径为0.46μm。所制备的粉体具有纯度高、氯离子等杂质少等特点。与其它湿化学法相比,加入有机添加剂的低温超强碱法具有工艺操作简单、节约资源和环境污染小的优点。 相似文献
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纳米四方多晶氧化锆粉体的表面特性与分散性 总被引:1,自引:0,他引:1
采用环保型强碱共沉淀法制备出了粒度为5 0nm的四方多晶氧化锆粉体。对由该粉体所制的悬浮体在不同条件下的 ζ电位测试表明 ,氧化锆微粒的等电点为 8.1 ;对分散剂在氧化锆微粒表面的吸附和分散作用进行了考察 ,聚电解质分散剂聚丙烯酸铵 (NH4PAA ,粘均分子量为 5 0 0 0~ 80 0 0 )使氧化锆微粒的等电点降低 ;对聚丙烯酸铵在纳米四方多晶氧化锆粉体上的等温吸附进行的研究发现 ,由于聚电解质分散剂的作用 ,悬浮体中纳米氧化锆粉体微粒表面的电动特性发生了显著变化 ,悬浮体的稳定性提高 相似文献
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以石灰石为原料,利用管式气体分散式反应器新工艺制备出了粒径30~70nm的碳酸钙粉体。采用X射线衍射(XRD)、扫描电镜(SEM)、粒度分布仪及红外光谱仪(Fr-IR)等测试手段,对产品的物相、形貌和粒度分布进行了表征。X射线衍射表明产物为六方晶系方解石型碳酸钙并且产品结晶性能良好;扫描电镜及粒度分析表明粒度大小均匀、分散性良好;红外光谱表明改性后硬脂酸钠已吸附在碳酸钙表面,碳酸钙颗粒基本呈单分散状态。管式气体分散式反应器制备纳米碳酸钙粉体的优点是工艺简单,操作容易,原料易得,生产的产品粒径小,粒度分布窄,易于工业化生产。 相似文献
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以水热法自制的纳米氧化锆为原料,用油酸对其进行表面改性。考查了改性温度、油酸用量对改性粉体的分散性的影响。用TEM、SEM对改性粉体进行表征。结果表明,改性后氧化锆从亲水性明显转变为亲油性,在弱极性溶剂中分散效果良好,改性效果明显。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献