Materials Science Forum Vol. 984

Abstract: To explore the soil fertility and tea quality and yield during the process of replacing chemical fertilizer with organic fertilizer, we established three experiment groups: experimental group I (formulated fertilization and biogas slurry), experimental group II (habitual fertilization) and experimental group III (formulated fertilization). Comparing with soil fertility, quality and heavy metal contents in fresh leaves among three groups in five tea gardens of Mingshan District, explores the effects of three different fertilization treatments on. The results showed that the experimental group I and experimental group III could improve soil fertility (including increasing the organic matter, total nitrogen and alkali-hydrolyzable nitrogen content) compared with the experimental group II. On the Fresh leaf yield, experimental group I> experimental group III > experimental group II(P<0.05), in which experimental group I was 27.26% higher than experimental group III. On yield, different treatments had less effect on the main quality components of fresh leaves (P>0.05).Compared with the experimental group II and the experimental group III, the heavy metal content of the experimental group I was higher, but no more than the food safety standard limit. In summary, experimental group I and experimental group III can effectively improve soil fertility and fresh leaf yield compared with conventional fertilization, particular experimental group I.

Abstract: This experiment was conducted to study the new shoot, bud and leaf of Fuding Dabai Tea, which was picked and purchased from Zhongfeng Tea Garden in Ya'an famous mountain area. The sensory quality, contents, pesticide residues and heavy metals of fresh leaves and green tea were studied and compared. The total soluble solids content and turbidity of water samples before and after the cleaning process were determined. The results showed that: (1) the weighted total score of sensory evaluation of finished tea added with fresh leaf cleaning technology was 91.15, which was 2.45 points higher than that of the control (without fresh leaf cleaning), and increased by 2.76%. (2) Fresh leaf cleaning process can significantly reduce the content of tea polyphenols, caffeine and water extract, and the ratio of phenol to ammonia, but has no significant effect on the content of amino acid and soluble sugar. (3) The total soluble solids of Q 2 are 4.3 times as much as Q1, and the turbidity of Q2 is 37.2 times as much as Q1. Cleaning process of fresh leaves can significantly reduce the indexes of agricultural residues and heavy metals. In conclusion, the cleaning process of fresh tea leaves can improve the sensory quality of tea to a certain extent, significantly reduce the content of bitter and astringent substances in tea leaves, effectively clean the surface impurities of fresh tea leaves, reduce pesticide residues and heavy metal content.

Abstract: Microtopography of fiber of Discorea nipponica Makino before and after mechanical activated by AGO-2 planetary mill was observed by SEM, and they changed the thick floccules to fine particles (D50 particle sizes were 10.18μm). Discorea fiber powder after mechanical activation had a narrow size distribution. According to XRD, the granularity and structures of discorea fiber with and without mechanical activation significantly differed, and the crystalline of discorea fiber was significantly converted into amorphous state after mechanical activation. On the basis of TG–DSC analysis, the activity of discorea fiber was enhanced, and certain internal energy were stored, and complete decomposition in advance. According to FT-IR, none of the functional groups of the mechanically activated discorea fiber disappeared, and no new functional groups appeared, which indicate that mechanical activation does not induce a chemical transformation of discorea fiber. According to the activation energy analysis, the thermal activation energy of dioscorea fiber after mechanical activation was18.49 kJ•mol, and the mechanical transfer activation energy was 56.06 kJ•mol, indicating that about 1/3 of the mechanical transfer activation energy was stored in the activated dioscorea fiber fine powder in the form of surface energy and internal energy.

Abstract: In order to obtain better quality and mechanical performances, the coating process of super-porous propellants was optimized. The mechanical performances of super-porous propellants were tested, under some conditions with different temperatures, different numbers of cladding layers, different thicknesses of the cladding layer and different ratios of inner and outer layers, through many different analytical methods including impact test, interrupted-burning test and three-dimensional video observation test. The results show that the mechanical performances of super-porous propellants are positively correlated with the temperature, the coating thickness and the ratio of the outer layer. The double-layer coating also can obtain better coating effect than the single-layer coating.

Abstract: The composite flooding formula utilizes the characteristics of polymer flooding and surfactant flooding to compensate for the shortage of single component chemical flooding, reduce the oil-water interfacial tension to a certain extent, and broaden the maintenance range of low interfacial tension. The combined effects and synergies in the oil displacement process enhance oil recovery and allow it to adapt to a wider range of reservoir conditions. In this paper, the high surface active polymer-surfactant flooding formula suitable for the Chang 6 reservoir in Ansai Oilfield was evaluated. The general technical index of the viscoelastic surfactant fracturing fluid and the composite flooding surfactant were evaluated. The technical requirements are evaluation criteria, and comprehensive evaluation is made from several aspects such as salt tolerance, interfacial tension and emulsifying properties.

Abstract: Iron and steel making is an industry with high energy consumption and greenhouse gas emissions. The work is to carry out the CO₂ capture experimental study as background of the blast furnace gas, increase the calorific value of the blast furnace gas and reduce greenhouse gas emissions and the energy consumption of CO₂ gas in the follow-up process cycle. In this paper, according to the principle of acid base neutralization, [EDA]L and [EDA]P contained amino ionic liquids are synthesized in ice water bath condition, which is made from lactic acid, formic acid and ethylenediamine. The synthesis process was explored, the viscosity and infrared spectroscopy of synthetic ionic liquid were characterized, the boiling point of ionic liquids were calculated, CO₂ absorption experiments were carried out under normal temperature and pressure. The results indicate that the compositions are ionic liquids having target structures and the maximum molar absorption of ionic liquid to CO₂ reaches 0.45 mol.

Abstract: Chiral metal-organic frameworks (CMOFs) have shown great promises in the applications of asymmetric catalysis with highly enantioselective. Herein, we briefly overview recent processes of MOF-based asymmetric catalysts based on a classification of reaction types. And we mainly focus on the structures and compositions of the active sites in these catalysts and their performances in specific reactions. In addition, some of their important unique features are critically emphasized alongside. Challenges of the future research are discussed also at the end of this review.

Abstract: Concrete of three different target strength, i.e. 17.23, 20.68 and 24.13 MPa was prepared using recycled brick concrete (RBC) and electric arc furnace slag (EAFS) blended as coarse aggregate. EAFS ratio was kept at 0%, 25% and 75% with respect to RBC. Concrete cylinder (200mmX100mm) specimens were prepared following standard procedure. Compressive and tensile strength on those concrete samples were conducted as per ASTM standard procedures. It was found that target compressive strength could not be achieved using 100% RBC as coarse aggregate. Through mixing EAFS with RBC both compressive and tensile strength of concrete was found to increase. 50% EAFS ratio was found to give maximum compressive and tensile strength for this type of blended aggregate concrete.

Abstract: Shortage of river sand and disposal of stone sludge are the problem of the construction and stone product industries, respectively. Utilization of stone sludge in mortar is one of the feasible strategies to solve these two problems. To study the effects of addition of stone sludge on the performance of mortar, 20 mixes of stone sludge powder mortar with various water/cement ratios and various stone sludge powder contents were produced for flowability measurement. To further study the governing mechanism of flowability and the packing densities of the solid proportions of the 20 mortar mixes were measured. Based on the packing density results, the average film thickness (AFT) of the 20 mortar mixes were calculated for flowability indication. Results proved that addition of stone sludge powder as sand replacement would decrease the flowability. The flowability was mainly governed by the AFT.

Abstract: In this study, the effect of polishing brick powder replacement cement slurry method on water absorption of motar is discussed. A series of mortar samples are prepared for testing water penetration amount at unit surface area with square of time and permeable porosity. The results show that the replacement of cement slurry with polished brick powder will increase the permeable pore of mortar and increase the sorptivity per unit area, thus effectively reducing the sorptivity of mortar at the same water cement ratio or strength.