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21.
介绍射水造墙的接缝原理,并把自己在施工过程中为确保接缝质量达到设计要求而总结出一些经验和处理措施提出为一起探讨。 相似文献
22.
Two different generators for ozone were tested, a traditional electrical discharge generator and a generator based upon UV–irradiation of air at 150–180 nm. It was demonstrated that the traditional generator gave slightly higher reductions in levels of color for equivalent ozone dosages. Both gases affected the molecular weight distribution in the way that the bigger molecules were broken down to smaller ones. No significant difference between the molecular weight reduction efficiency of the gases was found. 相似文献
23.
Three ketoacids; glyoxylic acid, pyruvic acid and ketomalonic acid, were identified in ozonated drinking waters and fulvic acid solutions using gas chromatography-mass spectrometry. It was found that the concentrations of ketoacids were much higher than those of aldehydes in ozonated waters. The significance of ketoacids in finished drinking waters is discussed. 相似文献
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25.
Katherine A. B. Logan Michael J. S. Floate 《Journal of the science of food and agriculture》1985,36(11):1084-1092
For 30 acid upland and hill soils, with initial pH from 3.5 to 5.8, and loss on ignition from 14% to 94%, cation exchange capacity varied with pH according to the relationship CEC = m pH+C, where m and C are characteristic of each soil. The slope m depended on loss on ignition (LOI), and is given by: m=Δ CEC/Δ=0.22 LOI+1.92. Because of these relationships, CEC measured at the natural pH of the soil (in 0.025 M MgSO4 solution) is more relevant to field conditions than a conventional measurement at pH7. An improved method for estimating lime requirement (LR) of these soils was developed, based on the relationship found between LR and the difference in CEC (ΔCEC) between that at the natural pH of the soil and that at the target pH of 5.5: LR=1.12 ΔCEC+1.48. Lime requirement can therefore also be estimated from loss on ignition using the earlier relationships, and is given by: LR=(0.25 LOI+2.15) Δ+1.48, where Δ is the difference between the natural pH (in 0.025 M MgSO4) and the target pH. Predictions based on this agreed well with results for a further 10 soils. 相似文献
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27.
A new technique of using ozone for water treatment is presented. This new technique consists of using a three-step-process composed firstly of ozone adsorption on an appropriate adsorbent, secondly water treatment, and thirdly regeneration of the adsorbent. Results regarding ozone adsorption (the first step) are presented in this paper. Different types of silica gel and a type of TiO2 have been tested for ozone adsorption. It was found that the physical characteristics of the silica gel affect its capacity for ozone. Titanium dioxide has shown ozone decomposition instead of adsorption as it contains Lewis acid sites. An exponential decrease of the silica gel capacity with its moisture content has been found. Linear isotherms in the range of ozone concentrations less than 100?g/m3 NTP have been found. A particle diffusion model with linear equilibrium isotherm has been used to model the breakthrough curves in fixed bed columns. 相似文献
28.
Equal Strain Consolidation by Vertical Drains 总被引:1,自引:0,他引:1
Chin Jian Leo 《Canadian Metallurgical Quarterly》2004,130(3):316-327
This paper shows the development of a series of closed-form solutions of equal strain consolidation in the presence of a vertical drain with smear and well resistance. Using an approach that considers the effects of both the radial and vertical drainage in a fully coupled fashion, solutions are obtained for the excess pore pressure and the degree of consolidation in the compressible soil subjected to a step- or ramp-loading situation. The closed-form solutions in the present paper may be evaluated in an electronic spreadsheet on a standard personal computer. 相似文献
29.
The Steady radial distribution of chemical species in a wire‐to‐cylinder ozone generator filled with pure oxygen has been computed by applying four different plasma chemistry models of increasing complexity. The most complete model considers ten species (e, O2 +, O2 ?, O3 ?, O?, O2, O2(1Δg), O2(1∑g +), O and O3) and 79 reactions, including ionization by electron impact, electron attachment and detachment, electron-ion recombination, charge transfer, etc. The chemical model is coupled with the electrical model through Poisson's equation. The spatially averaged ozone density has been computed as a function of the current intensity and compared with the experimental values obtained by UV spectroscopy. 相似文献
30.
The effect of gas-liquid contacting conditions in a static mixer on ozone transfer efficiency and reduction of Bacillus subtilis spores was studied in an experimental ozone contactor. An empirical mathematical model was developed that related the transfer efficiency in the experimental system to the superficial liquid velocity in the mixer, the gas-liquid flow rate ratio and the height of the down-stream bubble column. Spore reduction was determined primarily by the dissolved ozone concentration-time (Cavgtm) product in the reactive flow segment and was independent of the gas-liquid contacting conditions in the static mixer. In an integrated ozone contacting system, the static mixer should be designed to maximize ozone mass transfer while the reactive flow segment should be designed for efficient microorganism reduction. 相似文献