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11.
The adhesion behavior of di-n-butyl phthalate (DBP) onto different substrates (quartz, glass, and silicon) used as wafer surfaces was studied by using an in situ UV spectrophotometric technique. The results from the closed cell experiments revealed that greatest extent of DBP adhesion occurred on the quartz chip (0.154 μg cm−2), followed in the order by the glass (0.054 μg cm−2) and silicon (0.039 μg cm−2). By means of the in situ spectrophotometric observation, application of an electrical field at 290 V cm−1 in the cell proved to be effective in inducing charging of DBP aerosols, which were consequently attracted towards the electrodes. This method can be applied to wafer storage and transport equipments to prevent wafer contamination from material outgassing representative by DBP. 相似文献
12.
Comparison of multicomponent fuel droplet vaporization experiments in forced convection with the Sirignano model 总被引:2,自引:0,他引:2
A. Daï f M. Bouaziz X. Chesneau A. Ali Ch rif 《Experimental Thermal and Fluid Science》1998,18(4):282-290
The vaporization of multicomponent fuel droplets was studied experimentally in a heated flow and the results were compared to the model proposed by Abramzon and Sirignano. The droplet was suspended on a permanent holder which was set up in a thermal wind-tunnel. This wind-tunnel was fitted with a video recording system and an infra-red camera. The period during which the droplet was suspended on the holder before the opening of the hot air flow damper was recorded. This first sequence corresponds to the droplet vaporization in natural convection, whose initial experiment conditions, especially diameter, temperature, composition of the droplet, are well known. Then the damper was turn on, and the sequence of forced convection begun. The initial diameter of the droplet was recorded by the video system. The other initial conditions of this second sequence cannot be determined experimentally. The distribution of temperature in the droplet and the surface temperature, the mass fraction distribution in the droplet and the surface mass fraction were unknown. These unknown parameters were determined by coupling our experiment with a model using “the film concept” in natural convection. Experimental results were compared with the calculations and found satisfactory, in natural convection as well as in forced convection initiated by this method. The method was tested in the case of a fuel mixture droplets (heptane–decane) for different initial concentrations and variable durations of the sequence in natural convection. 相似文献
13.
Khaula Shirin Saima Imad Sheraz Shafiq Kaneez Fatima 《Journal of Saudi Chemical Society》2010,14(1):97-100
Withania somnifera (family Solanaceae) has been studied to determine major and trace elements and their possible correlation with therapeutic value of the plant. Nine trace elements were determined in Withania somnifera. This important medicinal plant was found to be rich in Fe, Cu, Ni, Mn, and Zn. These trace elements are well known for curing diseases. The plant contains nutrient elements, which are best sources for fodder. 相似文献
14.
A new selective membrane electrode for the measurement of lead activities is proposed. The preparation of active components of the membrane is described. The ready made electrode insert was used in which the PVC membrane was replaced by the prepared membrane. Experimental results document the emf response of profile, the selectivity, the detection limit and the effect of the sample media. The prepared electrode was applied for the measurement of the lead concentration in water samples. Activated alumina micro-column was used for the pre-concentration of lead in the analyzed water samples. The obtained results were compared with those determined by atomic absorption spectrometry. 相似文献
15.
16.
Nanocrystalline cobalt ferrites with nominal composition CoCrxFe2−xO4 ranging from x=0.0 to 0.5 with step increment of 0.25 were prepared by sol–gel auto combustion and chemical co-precipitation techniques. A comparative study of structural, electrical and magnetic properties of these ferrites has been measured using different characterization techniques. Structural and micro-structural studies were measured using X-ray diffraction, Fourier transform infra-red spectroscopy (FTIR), scanning electron microscopy and atomic force microscopy. Crystallite sizes of the series are within the range of 12–29±2 nm. Lattice parameters decrease by increasing Cr3+ concentration. FTIR confirms the presence of two lattice absorption bands. DC electrical resistivity increases to a value of ∼1010 Ω-cm with increase in Cr3+ concentration, but the most significant increase is in samples prepared by sol–gel combustion. Dielectric properties have been measured as a function of frequency at room temperature. Dielectric loss decreases to 0.1037 and 0.0108 at 5 MHz for chemical co-precipitation and sol–gel combustion, respectively. Impedance measurements further helped in analyzing the electrical properties and to separate the grain and grain boundary resistance effects using a complex impedance analysis. Magnetic parameters were studied using a vibrating sample magnetometer in the applied field of 10 kOe. The saturation magnetization decreased from 63 to 10.8 emu/gm with increase in Cr3+ concentration. 相似文献
17.
ApracticalmethodofinvestigatingthestraylightinlaserRamanspectrophotometerYINJianping,ZHUShiqun(DepartmentofPhysics,SuzbouUniv... 相似文献
18.
双离子束溅射淀积DLC膜的红外特性 总被引:1,自引:0,他引:1
用双离子束溅射法在50℃以下的玻璃基片上淀积了类金刚石碳(DLC)膜.研究了轰击离子能量、轰击离子束流密度及轰击源内氢/氩流量比例对淀积片红外透射特性的影响.所用波段是1.5~5.5μm.结果表明,对所有淀积样片,其相对透过率均随波长增长而增大.在每组实验中,随如上各可变参量的增大,各样片的相对透过率~波长曲线均有先上升后下降的规律.确定了各组相应的临界参数.结果还表明,轰击源不含氢并不影响DLC膜的制取,但轰击源合氢时所制得的膜具有更好的红外透射性.从结构变化的角度解释了上述规律. 相似文献
19.
In this article we investigate charged particles in gauge theories. After reviewing the physical and theoretical problems,
a method to construct charged particles is presented. Explicit solutions are found in the abelian theory and a physical interpretation
is given. These solutions and our interpretation of these variables as the true degrees of freedom for charged particles,
are then tested in the perturbative domain and are demonstrated to yield infra-red finite, on-shell Green’s functions at all
orders of perturbation theory. The extension to collinear divergences is studied and it is shown that this method applies
to the case of massless charged particles. The application of these constructions to the charged sectors of the standard model
is reviewed and we conclude with a discussion of the successes achieved so far in this programme and a list of open questions.
An erratum to this article is available at . 相似文献
20.