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51.
Sa?a?NovakEmail author Susana?Maria?Henriques?Olhero José?Maria?Fonte?Ferreira Andreja?Zupan?i? 《Rheologica Acta》2004,43(5):559-566
Due to the hygroscopic nature of fine alumina powders, the presence of water may have a detrimental effect on the rheological properties of a suspension in melted paraffin for low-pressure injection moulding (LPIM). For this reason, a modification of the powder surface from hydrophilic to hydrophobic is essential for the production of high-quality moulded ceramics. In our paper, the efficiency of the application and the chemisorption of protective monomolecular layers of a long-chain carboxylic acid or its salts will be presented. The effect of the powder treatment on the shear viscosity and the viscoelastic properties of the suspensions for LPIM as well as on their stability in terms of the detrimental effect of water will be discussed.This paper was presented at the first Annual European Rheology Conference (AERC) held in Guimarães, Portugal, September 11-13, 2003. 相似文献
52.
53.
Feifel R Burmeister F Sałek P Piancastelli MN Bässler M Sorensen SL Miron C Wang H Hjelte I Björneholm O Naves de Brito A Gel'mukhanov FK Agren H Svensson S 《Physical review letters》2000,85(15):3133-3136
The femtosecond dissociation of HCl after core excitation has been studied through the resonant Auger decay. The spectra contain contributions from decay occurring at both "molecular" and "atomic" internuclear distances. We have observed a new interference mechanism in these spectra: An atomic spectral line develops into a negative spectral contribution, a "hole," when detuning the excitation energy from the maximum of the Cl2p(-1)sigma(*) resonance. Resonant x-ray scattering theory quantitatively explains this behavior as due to a novel destructive continuum-continuum interference between molecular and atomic contributions to the Auger decay. 相似文献
54.
55.
介孔分子筛Al-MCM-41的合成与催化异构化性能 总被引:1,自引:0,他引:1
采用正硅酸乙酯(TEOS)为硅源,九水硝酸铝为铝源,十六烷基三甲基溴化胺(CTMABr)为模板剂,在室温条件下合成了介孔Al-MCM-41分子筛.通过XRD、N2等温吸附、SEM、FTIR等分析测试手段表征了分子筛的介孔结构和表面性质.结果表明所合成的分子筛有良好的介孔结构和较高的有序度,并且有较高的比表面积(达到816 m2·g-1)和窄的孔径分布.采用程序升温的焙烧方式、凝胶Al/Si比最大范围控制在0.06~0.13有利于合成高度有序的介孔Al-MCM-41分子筛.评价结果表明,所合成的Al-MCM-41分子筛对桥式四氢双环戊二烯(endo-TCD)异构化反应合成挂式异构体exo-TCD及金刚烷具有较高的催化活性和极高的选择性. 相似文献
56.
57.
The hadronic and string cascade model and the corresponding event generator LUCIAE are used to study systematically the production
of the grey particles in (14.6, 60 and 200A GeV)0 + Em, (2004 GeV)Si + Em, (200A GeV)S + Em and (11.6A GeV)Au + Em reactions. The dependences of the mean multiplicity,
the multiplicity distributions and the polar angular distributions of the grey particles on the incident energy, the projectile
mass and the collision centrality observed in emulsion experiments, respectively, are all reproduced by LUCIAE calculations.
In addition the effects of the rescattering on the grey particle production are also investigated.
Project supported by the National Natural Science Foundation of China (Grant Nos. 19575071 and 19875019) and DFG of Germany. 相似文献
58.
针对双弹丸同时着靶情况下的立靶坐标测量问题,提出一种圆形阵列光电探测系统的双目标识别方法。采用光电探测器件组成1个圆形的探测阵列,并将3个发光角度均为60°的扇形一字线激光器均匀设置于圆形探测阵列上组成探测光幕。当2发弹丸同时穿过探测光幕时,会在圆形探测阵列上产生6个弹丸投影,通过信号处理电路识别6个弹丸投影的中心位置,最后通过系统弹丸着靶坐标测量公式计算得到2发弹丸的着靶坐标。在对系统测量原理进行论述的基础上,建立了系统的弹丸着靶坐标测量模型,并对坐标测量误差进行了分析和仿真。仿真结果显示,系统在测量靶面为1 m×1 m时的X坐标测量误差标准差最大为2.7 mm,Y坐标测量误差标准差最大为0.6 mm。实验结果表明,系统在测量靶面为1 m×1 m时的X坐标测量误差标准差为2.22 mm,Y坐标测量误差标准差为1.98 mm。因此,该文所提出的系统可以有效测量弹径4.5 mm及其以上的双弹丸着靶坐标。 相似文献
59.
Saéda Didaoui Ahmed Ait-Kaci Mareck Rogalski 《The Journal of chemical thermodynamics》2010,42(10):1261-1264
(Solid + liquid) equilibrium (SLE) of thiophene or diethylsulfide with n-heptane, n-octane or n-dodecane mixtures was measured by a static method. All the systems under study are simple eutectic systems. The DISQUAC group contribution model is fairly successful in predicting SLE. 相似文献
60.
Palladium-based catalysts were prepared by the ion-exchange method with dealuminated HY zeolite as support. The support dealumination
was realised using acid solution of HNO3, HCl or H2SiF6. The high activity of prepared catalysts for methane combustion was observed. This activity was dependent on the Al concentration,
structural and textural properties of the support changed after the dealumination. Especially, Pd loaded on supports developing
a second pore system, and having the highest Si/Al ratio, was more active than that on unmodified supports. It was also expected
that the active sites in the methane combustion, which are suspected to be PdO, were influenced by the acidic properties of
the support. 相似文献