共查询到20条相似文献,搜索用时 93 毫秒
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《高校化学工程学报》2020,(2)
聚四氟乙烯(PTFE)因其优异的耐腐蚀性和耐热性可被用作浸渍剂制备不透性石墨,为了缩短聚四氟乙烯浸渍石墨的工艺耗时以及增强浸渍效果,进行了浸渍和塑化工艺的优化研究。在常温、0.7MPa条件下对石墨分别进行1、2、3、4次浸渍处理,后在常压、380℃条件下塑化,并对浸渍塑化后的石墨进行密度、增重率、开孔气孔率、偏光显微镜、耐热性和抗压强度等性能表征分析。结果表明:石墨密度、增重率和抗压强度随着浸渍次数的增加而升高,开孔气孔率和耐热性能随浸渍次数的增加而降低,n浸1塑工艺比n浸n塑工艺浸渍石墨的效果好;石墨经3浸1塑工艺处理后,其抗压强度高达50.1 MPa,开孔气孔率低至0.754%. 相似文献
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《炭素技术》2018,(5)
为探究不同浸渍固化次数对酚醛树脂浸渍石墨性能的影响,以热固性酚醛树脂为浸渍剂,在160℃、0.72 MPa条件下对普通中密石墨分别进行不同次数浸渍固化处理,并对浸渍固化后的石墨进行了偏光显微镜、密度、增重率、开孔气孔率、热重和抗压强度等表征分析,以比较不同浸渍固化次数下石墨的性能。结果表明:石墨的密度、增重率和抗压强度随着浸渍固化次数的增加而升高,开孔气孔率和耐高温性能则随浸渍固化次数的增加而降低。从缩短生产周期、降低生产成本和提高经济效益的角度出发,在满足石墨耐高温性能和抗压强度的使用条件下,只需对石墨进行3次浸渍固化处理;若对石墨的抗压强度有更高的要求,则需对石墨进行不少于4次的浸渍固化处理。 相似文献
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冷等静压坯料在焙烧后的制品内部会形成许多大小不一的气孔,需进行浸渍处理提高强度和基体致密性,本文围绕影响浸渍效果的各项主要工艺因素展开讨论与研究。实验结果表明:最优的浸渍工艺参数温度220℃、加压0.9MPa、保压时间为60min。通过相同实验因素下的对比试验,制品的体积密度会随着浸渍次数的增加而提升,但其提升的幅度却逐次减小。通过五焙四浸渍的工艺可将制品的体积密度提高到1.79g/cm~3。 相似文献
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铝掺杂氧化锌(ZAO)透明导电膜兼具电阻率低和透光性好的特点,在光学与光电子领域具有广阔的应用前景.本文以微米级的高纯超细ZnO和Al2O3粉体为原料,通过控制适当的素坯成型压力,烧结前增加冷等静压环节,优化烧结工艺,制备出了高致密度和低电阻率的ZAO靶材.在16 MPa的成型压力,120 MPa冷等静压,1350℃×1h的烧结工艺下,制备出了高致密度和低电阻率的ZAO靶材,其致密度达98.0%,电阻率为1.8 × 10-2 Ω·cm,接近于热等静压所制备出的ZAO靶材.利用自制靶材,通过射频磁控溅射法,进一步制备出了ZAO薄膜,透光率达到88.6%,最低电阻率达到2.1×10-3 Ω·cm. 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