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Due to the unique structure and high water repellency of surface of superhydrophobic materials, when superhydrophobic coating is applied on metal materials, it can prevent the metal substrate from contacting corrosive medium and therefore, largely improving the corrosion resistance and service life of the metal materials.In this paper, the wetting mechanism of solid surface and the basic concept of superhydrophobic materials were firstly explained; then, the common techniques of fabricating superhydrophobic coatings on surface of metals were introduced; finally, the recent developments and protection applications of superhydrophobic coatings on different metal materials, including steel, aluminum and magnesium, were summarized and discussed.

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A comparative study on the reactivity of Shenmu char with CO2 and steam was conducted at the temperatures from 900 °C to 1 050 °C using isothermal thermogravimetric analysis method. To better understand the reaction activity of residual carbon, the homogeneous model, the shrinking un-reacted core model, the integrated model and the modification volumetric model were applied to correlate the relationship between reaction rate and carbon conversion at the late gasification stage. The results show that both the integrated model and the modification volumetric model have a better fitting accuracy. The fitting accuracies of the homogeneous model and the shrinking un-reacted core model change with the gasification temperatures and the agents. At the late stage, the ranges of the apparent activation energy of Shenmu char in the atmosphere of CO2 and steam are 200. 65-231.00 kJ/mol and 105.48-169. 10 k J/tool, respectively. The apparent activation energy calculated with the modification volumetric model is approximately 36 kJ/mol higher at the late stage than that at the early and middle stages. Shenmu coal char gasification was under chemical reaction control at the late stage within the experimental temperature range. [ABSTRACT FROM AUTHOR]

Based on the staged conversion technique of brown coal pyrolysis, partial gasification and residual carbon combustion in circulating fluidized beds, rapid and slow coal char were produced from the brown coal of Shigouyi coal mine in Ningxia, at the temperatures from 700 °C to 950 °C in a horizontal tube furnace. The effects of pyrolysis conditions on the surface morphology and structure of the coal chars were investigated. A contrastive study was conducted using thermogravimetric technology, testing the reactivity of coal chars gasification with steam and CO2. The effects that gasification temperature, pyrolysis temperature and pyrolysis rate have on the gasification reactivity of coal chars were also analyzed. The results show that gasification temperature is the most important factor influencing gasification rate, while pyrolysis temperature has a weaker effect. However, there is great difference in gasification reactivity between steam and CO2, which decreases as gasification temperature rises. Compared to steam gasification, pyrolysis conditions have greater influence on CO2 gasification. The relation of reaction indexes between steam and CO2 gasification can be expressed using a quadratic regression equation, and a linear relationship exists between the distributed activation energy of both reactions in a carbon conversion range from 10% to 80%. [ABSTRACT FROM AUTHOR]

To globalize teaching Chinese as a second language, there arises an increasing demand for the perfection of the relevant theories, in particular those for overseas teenagers, in the areas of" what to teach", "how to teach", and "how to learn". In fact, we do have witnessed such development in the past few years along our teachers going out and foreigners coming into China, a situation that has provided the opportunity for interaction and hence given rise to some common views. Yet, there is still a long way to go for the betterment. [ABSTRACT FROM AUTHOR]

quantitative structure-spectrum relationship (QSSR) model was developed to simulate C nuclear magnetic resonance (NMR) spectra of carbinol carbon atoms for 55 alcohols. The proposed model, using multiple linear regression, contained four descriptors solely extracted from the molecular structure of compounds. The statistical results of the final model show that R=0.982 4 and S=0.869 8 (where R is the correlation coefficient and S is the standard deviation). To test its predictive ability, the model was further used to predict the C NMR spectra of the carbinol carbon atoms of other nine compounds which were not included in the developed model. The average relative errors are 0.94% and 1.70%, respectively, for the training set and the predictive set. The model is statistically significant and shows good stability for data variation as tested by the leave-one-out (LOO) cross-validation. The comparison with other approaches also reveals good performance of this method. [ABSTRACT FROM AUTHOR]

In order to realize the photocatalysis of TiO2 in the sunlight and directly apply it to waste water treatment, the Gd-doped TiO2 nanofibre was synthesized using two-step synthesis method as follows: Firstly, potassium carbonate, titanium dioxide and proper gadolinium oxide (dopant) were calcined in the muffle at high temperature and the doped gadolinium K2Ti4O9 fibres were obtained; secondly, the fibre was heated using glycerol as solvent until Gd-doped TiO2 nanofibres were obtained. The synthesized samples were characterized using scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The results show that Gd-doped TiO2 nanofibre heat-treated by glycerol solvent can inhibit the agglomeration, so the grain diameter of the fibre is smaller than that without heat-treated with glycerol. Meanwhile, the diameter of the fibre decreases with the increase of the heating temperature and time. 97%–98% of Gd-doped TiO2 nanofibre is anatase. The photocatalysis results showed that the photocatalysis activity of Gd-doped TiO2 nanofibre is just a little lower than that of TiO2 powder. [ABSTRACT FROM AUTHOR]

The adsorption response behaviors with n-alkanethiol self-assembled monolayers (SAMs) formed on the surface of polycrystalline gold grains have been investigated in nitrogen and oxygen saturated tetrahydrofuran (THF) solutions by using in situ quartz crystal microbalance (QCM) and atomic force microscopy (AFM). Comparing with frequency-decreased process in the nitrogen saturated solution, the response behavior shows a frequency increased process in the oxygen saturated solution, indicating that the gold corrosion is accompanied to occur in the self-assembled process of organothiol that is due to the thiol induction and oxygen oxidation. In the presence of thiol and oxygen, the corrosion effect is stronger than the adsorption effect of organothiols, such as n-dodecanethiol molecules on gold, which causes gold loss from the QCM surface, made evident from the observation of many corrosive defects or holes produced on the surface of gold grains by AFM image. Furthermore, the kinetic behavior on the corrosion rate of gold dissolved in the organothiol solution with time has been examined. The maximum quantity of gold dissolved into the thiol solution can be calculated to be approximately 8.7 × 1013 Au atoms cm-2 from the QCM data during the strong corrosion process in the oxygen saturated solution. The corresponding gold corrosion rates at fast and slow stages can be estimated to be 9.2 × 1011 and 5.4 × 1010 Au atoms cm-2 s-1, respectively. The surface coverage of SAMs increases from 3.2 to 31.2%, while the gold loss decreases from about 6 to 0.6% of an Au monolayer in the self-assembled process. [ABSTRACT FROM AUTHOR]

Shenmu bituminous coal was pyrolyzed and then gasified in a 10 t/h circulating fluidized bed of coal fast pyrolysis system to investigate the operation characteristics, coal pyrolysis characteristics and product distribution in the fluidized bed pyrolysis reactor. The results show that the contents of H2 and CH4 is high in pyrolysis gas with the low heat value of about 11~15 MJ/m³. The tar distillation range analysis demonstrate that light fraction content is about 47.00%. Proximate analysis of semi-coke clearly displays that the content of fixed carbon content is high and that of volatile is low. [ABSTRACT FROM AUTHOR]