超细粉体填料表面化学修饰

研究了表面改性剂组成、用量、改性时间等对氢氧化铝超细粉体填料表面化学修饰效果的影响,并浅析了改性机理。

Processing of Aniline Aerofloat Wastewater with SBR System and Its Biodegradation Mechanism

ObjectiveThis study aimed to investigate the biodegradation effect and biodegradation mechanism of aniline aerofloat wastewater. MethodSmall-scale processing of simulated aniline aerofloat wastewater was carried out with SBR （Sequencing Batch Reactor） system; intermediate products in the process were analyzed using high-performance liquid chromatography. ResultAccording to the experimental results, the small-scale process was basically stably operated after 40 days of activation and regulation, leading to relatively ideal degradation effect on aniline aerofloat, the COD removal efficiency reached 64.3% , degradation rate of aniline aerofloat reached 93.4%, which could be applied in the treatment of mine flotation wastewater containing such pollutant. During the degradation process, pH increased from 5.83 to 6.60 and then dropped to 6.17, which might be caused by the thiocyanate ions and aniline generated in the degradation process. Aniline aerofloat mainly produced two preliminary products during the biodegradation process： aniline and a substance that was difficult to be biodegraded under aerobic conditions, which was the main reason for the relatively high COD value in effluent. Furthermore, aniline was eventually biodegraded. ConclusionThis study provided basis for the development of biological treatment of flotation wastewater in China and showed great significance for the improvement of ecological environment around the mines.

Application of Abnormal Touchdown PCR with High Degeneracy Primer in Amplification of Large-Family Genes

[Objective] The aim was to explore the special methods for amplification of large-family genes by using primers with high degeneracy.[Method] By using the primers with high degeneracy,conventional PCR,conventional touchdown PCR and the optimized abnormal touchdown PCR were respectively carried out to amplify the genomic DNA of Cyprinus carpio.[Result] Only one evident electrophoretic band and a few Sox genes were obtained by using normal PCR;no obvious electrophoretic band but dispersive product was obtained by normal touchdown PCR;ideal result was obtained by the abnormal touchdown PCR that three evident electrophoretic bands and much more Sox genes were amplified.[Conclusion] The research provided theoretical basis for the optimization and selection of PCR amplification conditions of the large-family genes.

Recovery of high purity silicon from SoG crystalline silicon cutting slurry waste

The composition and size distribution of cutting waste were characterized. The Si-rich powders were obtained from the cutting waste using a physical sedimentation process, and then further purified by removing impurity using acid leaching. The effects of process parameters such as acid leaching time, temperature and the ratio of solid to liquid on the purification efficiency were investigated, and the parameters were optimized. Afterwards, the high-purity Si ingot was obtained by melting the Si-rich powders in vacuum furnace. Finally, the high purity Si with 99.96%Si, 1.1×10^-6 boron （B）, and 4.0×10^-6 phosphorus （P） were obtained. The results indicate that it is feasible to extract high-purity Si, and further produce SoG-Si from the cutting slurry waste.

Advances in Biodegradation of Aflatoxins

Aflatoxins are secondary metabolites of fungi such as Aspergillus flavus and Aspergillus parasiticus. They are one of the contaminants most common in food and feed, with high toxicity and carcinogenicity. Aflatoxins usually enter animal body together with feed and then enter human body by food chain, thereby seriously threatening human health. In recent years, the degradation of aflatoxins has become a hot research topic. This study overviewed the characteristics and detoxification ways of aflatoxins, specifically for the advances in biodegradation and degradation products of aflatoxins.

Study on the Effects of Reducing Blood Lipid by Flavonoids from Ampelopsis grossedentata on Hyperlipidemia Rats

In order to study the effects of Ampelopsis grossedentata on endogenous cholesterol biosynthesis and the effects of reducing blood lipid in hyperlipidemia rats,extraction of flavonoids from Ampelopsis grossedentata by using ethanol(TFAG),and the effects of TFAG on intracellular cholesterol synthesis were detected by amphotericin B-cell model;SD hyperlipidemia rat model was established by feeding high fat diet.A formulated medicine called Xuezhikang was used as a positive control,and TFAG of different doses were administered to the stomach for 30 d continuously to measure the indexes of heart,liver tissue homogenate and serum;part of the liver was taken for pathological observation.The results showed that TFAG could significantly inhibit the synthesis of cholesterol in cells.TFAG of different doses could significantly reduce the content of TC and TG in serum of hyperlipidemia rats,and increase the content of HDL;TC and TG in heart and liver were also decreased;besides,it could increase the content of SOD,CAT and GSH in the liver of hyperlipidemia rats,and reduce the content of MDA.The results of pathological section showed that TFAG could improve the damage degree of hepatocytes in hyperlipidemia rats,and the effect of high dose group was similar to that of Xuezhikang group.In general,TFAG has good antioxidant and reducing blood lipid effects,and can effectively inhibit liver steatosis.

Biomass Allocation Patterns of Alpine Grassland Species and Functional Groups along a Precipitation Gradient on the Northern Tibetan Plateau

Variations in the fractions of biomass allocated to functional components are widely considered as plant responses to resource availability for grassland plants. Observations indicated shoots isometrically relates to roots at the community level but allometrically at the species level in Tibetan alpine grasslands. These differences may result from the specific complementarity of functional groups between functional components, such as leaf, root, stem and reproductive organ. To test the component complementary responses to regional moisture variation, we conducted a multi-site transect survey to measure plant individual size and component biomass fractions of common species belonging to the functional groups： forbs, grasses, legumes and sedges on the Northern Tibetan Plateau in peak growing season in 2010. Along the mean annual precipitation （MAP） gradient, we sampled 7o species, in which 2o are in alpine meadows, 20 in alpine steppes, 15 in alpine desert-steppes and 15 in alpine deserts, respectively. Our results showed that the size of alpine plants is small with individual biomass mostly lower than 1.0 g. Plants keep relative conservative component individual responses moisture functional fractions across alpine grasslands at the level. However, the complementary between functional components to variations specifically differ among groups. These results indicate that functional group diversity may be an effective tool for scaling biomass allocation patterns from individual up to community level. Therefore, it is necessary andvaluable to perform intensive and systematic studies on identification and differentiation the influences of compositional changes in functional groups on ecosystem primary services and processes.

Recent Advances in Colloidal Lubricant Detergents

Overbased lubricant detergents are important components in lubricating oil. Recently, a lot of papers about the synthesis mechanism, colloidal structure, acid neutralization and antifrictiorL properties of overbased detergents have been published with the development of experimental techniques, which can help us better understand the process of preparation and application of overbased detergents and propound new strategies for improving various performances of overbased detergents. In the future, the synthesis of environmentally friendly and multi-functional lubricant detergent using biodegradable vegetable oil instead of mineral oil as raw materials will be a primary objective for the colloidal lubricant detergent industry.This paper mainly presents the latest advances in the investigation of colloidal lubricant detergents.

Biodegradation Kinetics for Pre-treatment of Klebsiella pneumoniae Waste with Autothermal Thermophilic Aerobic Digestion

Biodegradation parameters and kinetic characteristics for pre-treating waste strains of Klebsiella pneu-moniae were studied in laboratory scale with an insulated reactor by an innovative technique,autothermal thermo-philic aerobic digestion(ATAD) . Based on an Arrhenius-type equation,an empirical model was developed to corre-late the removal of total suspended solid(TSS) with the initial TSS concentration,influent reaction temperature,aeration rate and stirring rate. The reaction temperatures of the ATAD system could be raised from the ambient temperatures of 25 °C to a maximum temperature of 65 °C. The exponentials for the initial TSS concentration,aeration rate and stirring rate were 1.579,-0.8175 and-0.6549,respectively,and the apparent activation energy was 6.8774 kJ·mol-1. The correlation coefficient for the pre-exponential factor was 0.9223. The TSS removal effi-ciency predicted by the model was validated with an actual test,showing a maximum relative deviation of 10.79%. The new model has a good practicability.

Aerobic biodegradation of di-n-butyl phthalate by Xiangjiang River sediment and microflora analysis

Di-n-butyl phthalate (DBP),one of phthalate acid esters (PAEs),was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the sediment. The sediment sample was incubated with an initial concentration of DBP of 100 mg/L for 5 d. The biodegradation rate of DBP was detected using HPLC and the degraded products were analyzed by GC/MS. Subsequently,the microbial diversity of the enrichment culture was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results reveal that almost 100% of DBP is degraded after merely 3 d,generating two main degraded products:mono-butyl phthalate (MBP) and 9-octadecenoic acid. After a six-month enrichment period under the pressure of DBP,the dominant family in the final enrichment culture is clustered with the Comamonas sp.,the remaining are affiliated with Sphingomonas sp.,Hydrogenophaga sp.,Rhizobium sp.,and Acidovorax sp. The results show the potential of these bacteria to be used in the bioremediation of DBP in the environment.

Effect of Microwave Athermal and Thermal Radiation in Wastewater Sludge Properties

Samples of thickened waste activated sludge （TWAS） at two different concentrations were exposed to microwave radiation. Some of the samples were not allowed to heat up, to study the athermal effect of microwaves. The samples exposed to microwaves where their temperature was allowed to increase showed a higher degree of chemical oxygen demand （COD）, protein and carbohydrate solubilization compared to a control. The size distribution of particles was changed after exposure of TWAS to microwaves. These results were also observed in the samples exposed to microwaves but kept at a constant temperature, suggesting the occurrence of a microwave athermal effect. Thermally （samples experiencing a temperature increase） and athermally （samples that were maintained at ambient temperature） microwaved subsequent anaerobic biodegradation. samples produced more methane than the non-microwaved controls in

Development and validation of a stability-indicating HPLC method for the determination of retigabine and its related substances in drug substances

A stability-indicating high-performance liquid chromatography（HPLC） method has been developed and validated for the separation and determination of Retigabine and its related substances. The chromatographic separation was achieved on Agilent Eclipse Plus C18 column（4.6 mm×150 mm, 5 μm）. The mobile phase was constituted of triethylamine-phosphate buffer as A and acetonitrile as B. The analysates were then eluted under the gradient conditions as description in this paper. The forced degradation study validated that the newly developed method was specific and selective to the degraded products. The performance of the method was verified according to the present International Conference on Harmonisation（ICH） guidelines for specificity, linearity, accuracy, precision and robustness. The correlation coefficients for Retigabine and its six impurities were greater than 0.999, which was shown in the regression analysis. Limits of detection（LOD） of these impurities were in the range of 0.0092%–0.0103%, indicating the high sensitivity of the newly developed method. Accuracy of the method was determined on the basis of recoveries to be between 96.49% and 118.35% for all impurities. Relative standard derivation（RSD） receiving in the repeatability and intermediate precision experiment, was less than 1.0%. The method can be successfully applied to routine quantify and stability testing Retigabine and its related substances in bulk drugs.

Synthetic biodegradable functional polymers for tissue engineering:a brief review

Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly(glycerol sebacate) are summarized in this article. New developments in conducting polymers, photoresponsive polymers, amino-acid-based polymers, enzymatically degradable polymers, and peptide-activated polymers are also discussed. In addition to chemical functionalization, the scaffold designs that mimic the nano and micro features of the extracellular matrix(ECM) are presented as well, and composite and nanocomposite scaffolds are also reviewed.