Applied Mechanics and Materials Vols. 651-653

Abstract: Tea is a widely consumed beverage in the world and an important economic crop in China. However in recent years tea gardens were increasingly contaminated by heavy metals such as lead (Pb). Root uptake of Pb could contribute significantly to Pb accumulation in tea leaves due to the strong acidity of tea garden soils. To reduce the Pb bioavailability and absorption by tea plants, a pot experiment was conducted to evaluate the effects of 3 phosphate fertilizers separately with a normal application rate in the field of 0.2 g (P₂O₅) ·kg^-1 soil and a high application rate of 0.5 g (P₂O₅) ·kg^-1 soil on bioavailable Pb in tea garden soil and Pb absorption and accumulation by tea plants. Results showed that application of calcium magnesium phosphate significantly increased soil pH by up to 0.6 units from 3.50 to 4.13. Phosphate fertilizers resulted in an increase of bioavailable Pb concentration in tea garden soil under our experimental conditions. Pb concentration in tissues of the tea plants under different phosphate fertilizer treatments followed the order of root>stem>leaf. Calcium magnesium phosphate with a high application rate of 0.5 g P₂O₅·kg^-1 soil decreased Pb concentrations of roots, stems and leaves of tea plants significantly. For one phosphate fertilizer, Pb absorption in tea plants under high application rate was much lower than it under normal application.

Abstract: The dynamic viscoelasticity of the outer and inner part of bamboo with different ages was investigated using Dynamic Mechanical Thermal Analyzer (DMA). The results showed that,storage modulus (E’) and loss modulus (E’’) of both outer and inner part of bamboo were increased at temperature between 25-250°Cas the bamboo ages increasing. In addition, E’ and E’’ of the outer part of bamboo were higher of the inner part with the same bamboo age. Also a significant loss peak in E’’~T curves between 190-210°C was found. The peak values of E’’~ T curves of the outer part only shown slight variation with bamboo age increasing. However, significantly different of peak values was found in the inner part. This was caused by the difference of the chemical composition in outer and inner part of bamboo with different ages. The width of E’’ peak varied slightly in outer bamboo of different ages, but in the inner part , it was increased as the age increasing. This revealed that in the outer part of different ages, the chemical composition of the molecular values was closer, In the inner bamboo, it was increased as the age increasing..

Abstract: The molecular dynamics simulation studies on the microstructure evolution properties of amorphous Ca₇Mg₃ alloy during the isothermal annealing have been performed. The simulated structure factor S(q) of Ca₇Mg₃ is well agreed with the experimental data. Results indicate that the icosahedron structure plays dominate role in the structure transformation, and the smaller Mg atoms are much more probable to be the central atoms of the basic clusters of icosahedron.

Abstract: Cassava cultivars are self-compatible, sufficient pollination and fertilization are important factors affecting the rate of fruit set and fruit quality, but the effects of compatible pollination relationships on cassava pollen development and fruit set are poorly understood. In the present study, in situ pollen germination and compatible relationship were investigated by using self-pollination and cross-pollination between two cassava cultivars (SC5 and SC7). The observation in situ pollen germination was carried out with toluidine blue staining method under the fluorescence microscope. The result shows that after self-pollination for 20 min, the pollens, released from SC5 anthers, started to produce pollen tubes and the maximum germination rate (GR) was 39.2%. It cost 60 min for the pollen tubes carrying sperm cells to penetrate through the pistil extracellular matrices of the transmitting tract to the ovary. However, after cross-pollination for 10 min, the pollens started to germinate and maximum GR was 66.8%. It took 30 min for the pollen tube trip to reach ovary. Additionally, the analysis of fruit set indicated that pollination compatibility in cross-pollination was significantly higher than that in self-pollination. This work provided cassava cross breeding a clue that foreign pollen may facilitate fertilization and increase fruit set.

Abstract: The molecular dynamics simulation studies on the microstructure evolution properties of liquid Ca-Mg alloys during the rapid solidifications have been performed. The simulated structure factor S(q) of Ca₇Mg₃ is well agreed with the experimental data. Results indicate that the glass transition temperatures of CaMg₂ and Ca₇Mg₃ are 590 K and 550 K respectively with the cooling rate of 1×10¹² K/s. It also found that icosahedron is much easier to form in CaMg₂ system, and Ca-Mg alloys with more Mg content indicate higher glass forming ability.

Abstract: A sensitive fluorescent biosensing strategy based on structure-switching of molecular beacon for the detection of single nucleotide polymorphism is proposed in this study. In the absence of target DNA, only low background fluorescence can be detected since the formation of hairpin structure induces close proximity of fluorophore and quencher. On the contrary, the fluorescence intensity increases significantly after introduction of target DNA because structure-switching of molecular beacon results in separation of fluorophore and quencher. The change of fluorescence intensity is linear with concentration of target DNA, and a molecular beacon-based sensing system for fluorescent detection of single nucleotide polymorphism is fabricated. The target DNA can be sensitively detected in a linear dynamic range from 17.58nM-1.125μM with a low detection limit of 8 nM. Moreover, good reproducibility and high specificity are achieved.

Abstract: In this study, the input and output parameters of Phosphorus (P) for wheat production system were collected from the year 2000 to 2011 to evaluate the nutrient cycling and balances in North Central China, the Middle and Lower Reaches of the Yangtze River and Northwest China. The results showed that the P fertilizer application rates for each region were 44.5, 39.7 and 42.3 kg P/ha, the P brought from previous crop were 14.8, 1.6 and 2.6 kg/ha, and brought from seeding were 1.5, 1.0 and 0.9 kg/ha, respectively. The P input from atmospheric deposition and irrigation were considered zero. The P uptake by harvest in above-ground plant in North Central China, the Middle and Lower Reaches of the Yangtze River and Northwest China were 41.2, 53.2 and 17.0 kg/ha. As a result, the P balance in North Central China and Northwest China were both showing surplus by 19.6 and 28.8 kg/ha, and in the Middle and Lower Reaches of the Yangtze River showed deficiency. It is suggested that we need to adjust the P fertilizer input in China, in order to maintain the sustainable soil fertility and avoid the negative impact on the environment.

Abstract: Buckwheat is rich in active substances with hypoglycemic effects. Submerged fermentation, as the method of brewing buckwheat vinegar, not only has the advantages of shortening production cycle, saving materials etc, but also has high functional active substances. In this study, the process of the submerged fermentation of acetic acid fermentation was optimized by the orthogonal experiments of L9 (34), which was also on the basis of single factor experiments. The results indicated that the conversion rate of acetic acid can become 95.8% when the initial alcohol at 6% (v / v), inoculum at 10%, fermentation temperature 30°Cand fermentation time 60 h.

Abstract: In this paper,the clove essential oil was combined with β-Cyclodextrin and chitosan using the method of envelope binding,thus clove essential oil microencapsule antistaling agent was prepared.To detect the exterior characterization of microcapsule using SEM;To analyze the antimicrobial properties of microencapsules using the inhibition zone method, and the slow release rate of microencapsule was detected in 0, 2,30 °C. The results showed that the microencapsule had irregular shapes and their surfaces were covered with many cracks;the inhibition zone diameter of Rhizopus sp. and Penicillium citrinum diameter were 1.2 cm and 1.6 cm partly; microencapsules showed a slow release state under the three temperature conditions,and it had the slowest release rate under 0 °C condition.

Abstract: Dragon-pearl tea is a traditional Chinese drink consumed in Southwest of China. In the present study, the preventive effect of Dragon-pearl tea on gastric injury was determined in ICR mice. High concentrations of Dragon-pearl tea were observed to reduce the levels of the serum proinflammatory cytokines, IL-6 and TNF-α, compared with low concentrations of Dragon-pearl tea. Gastric secretion volumes were highest in control mice and reduced in 500, 1,000 and 1,500 mg/kg Dragon-pearl tea treated mice. The pH levels of gastric juice samples obtained from each group revealed the opposite correlation. Gastric injury levels in mice treated with Dragon-pearl tea were identified to be significantly reduced, demonstrating its anti-inflammatory properties. Administration of 1,500 mg Dragon-pearl tea (79.4%) by gavage was demonstrated to induce the highest inhibitory effect on gastric injury. Results of the current study indicate that Dragon-pearl tea exhibits marked preventive effects on gastric injury.