Papers by Keyword: Micro-Morphology

Abstract: The elastohydrodynamic lubrication numerical analysis of water-lubricated tenmat bearing with single sine-type peak, single V-type valley and single rectangular-type valley was carried out by using the Reynolds equation. The results show that, for the bearing with single peak, the partial pressure peak appears and the corresponding film thickness increases rapidly and then decreases; With the increase of the amplitude of the sine function, the partial pressure of the lubricating film is also increased, the partial film thickness is decreased, as the wavelength increases, the pressure and the film thickness of the convex portion widened, the peak remains substantially unchanged. For the bearing with single V-type valley and single rectangular-type valley, the partial pressure are decreased, the partial film thickness are increased; with the amplitude of the roughness function increases, the partial pressure are decreased, on the contrary ,the partial film thickness are increased; with the wavelength increases, the pressure and the film thickness of the convex portion widened.

Abstract: The micro-morphology of the moth wing surface was characterized by a scanning electron microscope (SEM). The contact angle (CA) and sliding angle (SA) of water droplet on the wing surface were measured by an optical CA meter. The wetting mechanism was discussed from the perspective of biological coupling. The moth wing surface is of superhydrophobicity (CA 143~156°) and low adhesion (SA 1~4°), and displays multiple-dimensional rough micro-morphology. The scales play a crucial role in the complex wettability of the wing. The average rate of CaCO₃ pollution removal from the wing surface is as high as 87.3%. There is a positive correlation (R=0.8777) between pollution removal rate and roughness index of the wing. The cooperation of chemical composition and micro-morphology contributes to the special wettability and outstanding self-cleaning performance of the wing. The moth wing can serve as a template for biomimetic design and preparation of novel interfacial material with multi-functions.

Abstract: Dot is the smallest structural unit of image printing. Micro-characteristic of each printing dot such as spreading area, dot shape and three-dimensional shape which are formed on the surface of substrates affect the image replication quality directly. It is significant to accurately extract and analyze dot microstructure in the process of image transfer for evaluating the quality of image replication .Different shapes of printing dots from the standard offset proof are extracted through microscopic test system. The optimal threshold segmentation algorithm was determined by experiment which gets accurate microscopic quantitative value of the dot, the obtained two-dimensional and three-dimensional shape of printing dot became the basis to evaluate the quality of image replication. The between-cluster variance method is used for dot image segmentation. The research was carried on to track image edge after image threshold and to extract the characteristic parameters to accurately characterize the two-dimensional shape, thus characterizing the image replication quality of dot plane form accordingly; on the basis of collected dot two-dimensional data, the experiment was conducted to combine with gray value differences of single dot caused from ink accumulation within its shape areas. Besides, dot density contour and three-dimensional data were quantized by programming in order to restore three-dimensional shape of printing dot on the surface of substrates quantitatively and intuitively. It shows that quality of dot micro-morphology is the fundamental guarantee of image replication quality. The changes of dot shape, area as well as three-dimensional shape in the process of image replication affect the printing quality. Extraction and analysis dot microstructure can detect dot replication quality intuitively which becomes new method to evaluate image replication quality.

Abstract: β-Sialonwhiskers which the molecular structuralformula of β-Sialonis Si₃Al₃O₃N₅(z = 3) were synthesized from fly ash and graphite under appropriate technological conditions by carbothermal reduction–nitridation process. The effects of carbon content, reaction temperature and reaction time on synthesis ofβ-Sialonwere analysed by XRD, SEM techniques. The results proved that, the condition of the carbon content over 80% is the best parameter to promote theβ-Sialon powder production. Compared to other kinds of temperature, 1430 °C is the optimal temperature to promoteβ-Sialon powder generation. Compared to 3h, holding time of 6h is promoting theβ-Sialon powder generation.The main morphology of β-Sialon was rod-like whisker.

Abstract: The effect of admixtures on the mechanical properties of recycled fine aggregate cement mortar was studied. The result indicated that compared with blank samples the 28d flexural strength, the compressive strength and osmotic pressure of cement mortar were increased by 15.6%, 35.5%, 41.1% respectively when adding silicone waterproofing agent 0.2wt%, naphdalin series water reducer 1.0wt%, polycarboxylate superplasticizer 0.8wt%. The micro-morphology and hydration products of mortar specimens was observed by SEM, XRD respectively.

Abstract: A modification of using fly ash grout of different levels was adapted to treat the surface of recycled fine aggregate (RFA).The physical properties of RFA before and after modification and the effect on the mechanical performance of cement mortar was studied.The result indicated that the modification of RFA could strengthen the enhancement effect on mechanical performance when modified by 15wt% fly ash grout. After modification, water absorption of RFA was 6.12% and decreased by 47.5%. The 28d flexural strength was increased by 17.4% and compressive strength was increased by 24.2% of RFA cement mortar compared with the reference samples. The superficial microstructure and sectional morphology of RFA was observed by scanning electron microscopy (SEM). The modification mechanism was carried out.

Abstract: The effect of some factors(dosage and grain size of recycled fine aggregate of construction waste, content of mineral admixture) on the properties of cement mortar was studied. The results indicated that when recycled fine aggregate particles gradation was areaⅡ, replacement percentage (sand) was 60%,dosage of mineral admixture was 36%, compared with blank sample, the 28d flexural strength and the compressive strength of cement mortar samples were increased by 30.7% and 37.2%, respectively. Micro-morphology of section on cement mortar was observed by SEM. Identifying the hydration products through XRD was carried out.

Abstract: The micro-morphology and metal elements composition of Inhalable particles (PM₁₀) in Huaian typical zone were studied in this paper using scanning electronic microscopy (SEM) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). PM₁₀ samples were collected for 24 h using high-volume air sampler from Qinghe zone. The SEM analysis showed that mineral particles with regular shapes were popular in PM₁₀ in Qinghe district. The composition of metal elements analysis showed that enrichment factor of Cr, Ni, Cu, Zn, Pb, Cd, As of are greater than 10, the results indicate that these elements mainly come from anthropogenic pollution. PM₁₀ in Huaian typical zone was more sourced from industrial pollution than other sources.

Abstract: List The active of MgO was produced from magnesite tailings under certain conditions. The effect of calcinations temperature on the crystal structure of MgO was analyzed by XRD and SEM. Crystal particle of MgO was calculated according to Scherrer formula. The microstructural differences between the MgO agglomerates were examined by SEM at different temperatures. The activity of MgO was evaluated though conductivity which was measured by the conductivity meter. The activity of MgO effected by calcinations temperature was studied. The result showed that magnesite tailings was fully decomposed when that was calcined for 60min with the calcinations temperature of 1050°C, and the activity of MgO was very high. Established a hydration and expansion model of MgO is proposed to explain the activity of MgO.

Abstract: The elastohydrodynamic lubrication (EHL) study of water-based ferrofluid bearing with single sine-shaped peak, rectangular-shaped valley and V-shaped valley was carried out. The influence of the amplitude and the width on the pressure and film thickness was discussed. The results reveal that the pressure and film thickness change apparently with the change of micro-morphology; The amplitudes of the local pressure peak and the film thickness increase with the increase of amplitudes; The widths of the local pressure peak and the film thickness increase with the increase of width.