Advanced Materials Research Vols. 726-731

Abstract: The experiment adopted the method of cultivating Hydrilla verticillata and algae in coexistence systems to study the inhibitory effect of Hydrilla verticillata on planktonic algae in eutrophic water. The results showed that allelopathic and competition of nutrition inhibitory effect were both affect the inhibition of Hydrilla verticillata on planktonic algae at initial concentration of 10⁵ cells·mL^-1, and the highest inhibition ratio on was 79% at undernutrition condition; opposite, allelopathic inhibitory effect played a major role at nutritional sufficiency, the highest inhibition ratio was 39%. Hydrilla verticillata played a role of “promoting with low biomass while inhibiting with high biomass” on planktonic algae, the optimal biological dosage of Hydrilla verticillata on inhibiting planktonic algae at initial concentration of 10⁵ cells·mL^-1 was 12g·L^-1. Hydrilla verticillata all produced inhibitory effect on planktonic algae at different initial concentrations, and the greater the initial concentration of planktonic algae, the higher the inhibition ratio of Hydrilla verticillata on planktonic algae.

Abstract: Four suspected Lactobacillus strains (XF1,XF2.XF3 and XF4) were isolated from one naturally fermented sauerkraut juice collected from Xifeng,Liaoning Province. By gram staining and catalase activity experiments,Two strains (XF1 and XF4) were retained.The strains were identified by 16S rDNA sequence analysis.The results showed that XF1 and XF4 were both identified as Lactobacillus curvatus.

Abstract: The bamboo powder is liquefied by microwave heating with polyethylene glycol (400), glycerin and EC as liquefiers and sulfuric acid as a catalyst. The microwave liquefaction process for bamboo powder polyhydric alcohols is studied with the single factor experiment to determine the optimal liquefaction conditions, which is: mass ratio of polyethylene glycol (400) and glycerin is 80:20; the liquefaction rate is 99% in the liquid-solid mass fraction at 4:1, sulfuric acid mass fraction at 3%, and microwave power at 800W for 15 minute reaction. Hydroxyl value for liquefied product of bamboo powder polyhydric alcohols is 300-400mgKOH/g. Analysis of liquefied products by infrared spectrum and GC-MS shows there are a great many such compounds as alcohol ethers and esters in liquefied products.

Abstract: Understanding the population dynamics of mosquitoes is fundamental to the study of the epidemiology of mosquito-borne diseases for the purpose of optimal control and prevention. In this paper, we presented a brief survey for former models for mosquito population and claimed that the effect of limited resource and temperature are important for the population dynamics of mosquito which should be considered in mosquito models.

Abstract: A detailed study was conducted to determine the current statues of the heavy metals in roadside dusts collected from universities in Beijing, China. Twelve universities were selected and analyzed to determine the occurrence, distribution, and assessment of heavy metals in roadside dusts. The results showed that Cr, Cu, Zn, Cd and Pb exhibited higher metal concentrations than the local soil background values, indicating that the pollution may come from anthropogenic input. The assessment by Geoaccumulation Index (I_geo) indicates that Cr and Ni are at the unpolluted level, Cu and Zn at the slightly polluted level, Cd and Pb at the moderately contaminated. The pollution level was in the following order: Cd > Pb > Zn > Cu > Cr > Ni.

Abstract: The three-component Mannich-type reactions of different ketones with various aromatic aldehydes and aromatic amines proceeds efficiently in the presence of catalytic amount of perfluoroalkylated-pyridine in a fluorous biphasic system without fluorous solvent, which has prompted various concerns involving cost, solvent leaching, and environmental persistence. The reactions give various β-arylamino ketones in good to excellent yield. The catalyst can be recovered by simple cooling and precipitation and used again.

Abstract: Quantitative Structure Activity Relationship (QSAR) can provide greater benefits by its application on a larger scale by collecting diverse measurements of biological activity data. It can help in designing effective inhibitors by considering specific effects of various types of substituents, thus reducing trial experiments. This quantitative technology can be utilized to improve the structure of the inhibitor molecule and to interpret the improved structure in terms of favorable biological interactions. In this paper, toxic effect of polar narcotic organic is analyzed by QSAR study method.

Abstract: There is an essential need to use computation-based quantitative structureactivity relationship (QSAR) modeling for providing information about the physicochemical properties of chemicals and their environmental fate as well as their human health effects. The major aims of this paper is to explore ways to predict and to identify hazardous combinations of chemicals relevant to humans and the environment. So we use QSAR modeling for toxicological predictions determine the potential adverse effects of reactive organic compounds in risk assessment.

Abstract: This research studies the effect of cadmium adsorption-desorption kinetics with different pyrolysis temperature biochar. The biochar which derived from rice husk at 300°C, 400°C, 500°C temperature for 30 minutes were added into Cd²⁺ solutions of 0.5 mg/L, 2.5 mg/L and 5 mg/L respectively. The optimal model of cadmium adsorption desorption kinetic behavior is the Level 1 dynamic equation. Indicates the increasing Cd²⁺ adsorption ability of biochar with pyrolysis temperature rising. Biochar also shortens adsorption process at relatively low Cd²⁺ initical concentrations.

Abstract: Over the past several decades, grassland degradation has become severe in Inner Mongolia, leading to decreased grass coverage and increased distribution of Caragana microphylla. In order to find out new explanation for the expansion of C. microphylla in degraded grassland, we grew two-year seedlings in phosphorus (P) deficient soil supplemented with P supply ranging from 0 to 60 mg kg^-1. The simulation parameters of light response curves and chlorophyll fluorescence parameters were all generally similar among different soil P supplies. Only maximum total photosynthetic rate (Pmax) and PSII potential activity (Fv/Fo) were reduced at 0 mg kg^-1 soil supply, and high P supply caused P toxicity. C. microphylla was non-limited by P-deficiency and adapted well to the low-P Inner Mongolia steppe. The advantage of C. microphylla in P-limited natural grassland provided new explanation for the expanding of C. microphylla in degraded Inner Mongolia steppe.