Applied Mechanics and Materials Vols. 644-650

Abstract: Sources of heavy metals in marine environment could be cagetoried as natrual source and artificial source. The portion from natrual source forms the environmental background value of heavy metal. This paper proposed the theory of the structure of environmental background value for heavy metal. Finally, this paper applied this theory in the analysis of the environmental background value of Cadmiun (Cd) in Jiaozhou Bay waters. This theory provides basis for pollution control and remediation of marine environment.

Abstract: In order to study changes of aroma components of hot-air drying and vacuum drying banana slices, using SPME-GC/MS coupling on the aroma components were analysed bytechnology. Different drying methods kinds of aroma constituents and the content of banana samples have great differences. Hot air drying characteristic flavor substances are aldehydes, vacuum drying of flavor substances disappear is alcohols, acids and aldehydes.

Abstract: In the last decade, RNA interference (RNAi) by small interfering RNAs (siRNAs) has become a hot topic in both molecular biology and bioinformatics. The success of RNAi gene silencing depends on the specificity of siRNAs for particular mRNA sequences. As a targeted gene could have thousands of potential siRNAs, finding the most efficient siRNAs among them constitutes a huge challenge. Previous studies such as rules scoring or machine learning aim to optimize the selection of target siRNAs. However, these methods have low accuracy or poor generalization ability, when they used new datasets to test. In this study, a siRNA efficacy prediction method using BP neural network (BP-GA) was proposed. For more efficient siRNA candidate prediction, twenty rational design rules our defined were used to filter siRNA candidate and they were used in the neural network model as input parameters. Furthermore, the performance optimization of network model has been done by using genetic algorithm and setting optimal training parameters. The BP-GA was trained on 2431 siRNA records and tested using a new public dataset. Compared with existing rules scoring and BP methods, BP-GA has higher prediction accuracy and better generalization ability.

Abstract: In order to select preferred microbial efficiently and quickly, we design and develop a kind of PC software. This article describes the framework of designing automatic multi-mode spectral detection system, which uses Modbus protocol. This system effectively combines sample injection, heated, detected the reasonable results and data analysis, and achieves automatic detection process.We realize that our software is object-oriented programming with the help of abstraction of each module, making use of Unified Modeling Language (UML) .The back-ground adopts SQL Server2008 as database to store the results of data. The software is easy to operate, user-friendly, reliable and the most important is able to run stability.

Abstract: In this paper,6 not covered DNA sequence annotation (gene6) coding region is predicted, according to the spectrum or signal-to-noise ratio characteristics,the effectiveness of the coding and non-coding interval classification are discussed,and the classification errors produced during the classification recognition for proper analysis.Key word. Gene identification;Spectrum curve;improvement

Abstract: Polymerase chain reaction (PCR) and fluorescence quantitative polymerase chain reaction (qRT - PCR) is a major means of detection of genetically modified food, whose key is to extract high quality nucleic acid in quick and high flux. The main nucleic acid extraction method is hexadecyl trimethyl ammonium bromide (CTAB) and sodium dodecyl sulfate (SDS) and kits. Because operation of CTAB and SDS method are cumbersome, require the use of organic solvent and centrifugal unceasingly, thus can not meet the requirement of the rapid development of high throughput; and because of the high price of kit method, its application in the daily inspection is also limited. At the same time, the development trend of genetically modified detection based on nucleic acid level is multiple tests; the key is the preparation of different kinds of fluorescent microspheres and specific probe of microspheres. To solve above problems, this paper put forward nucleic acid extraction method on the basis of the magnetic separation technology.

Abstract: This paper mainly introduced the performance of a home-made Z-N catalyst in different reaction conditions to produce homopolyethylene and copolyethylene. The influence of hydrogen pressure, n (Al)/n (Ti) ratio, comonomer concentration on catalyst activity and polymerization kinetics were examined, analyze and characterization the polymer performance. The rule, which explain the effect on Z-N catalyst of reaction conditions were given in the article [1][2][3][4].

Abstract: The Ni-based ammonia decomposition catalysts were prepared by vacuum dip-molding, the structures of catalyst carriers and nickel grain were characterized by XRD and SEM. Through three dip-activate technics, the Ni content in catalyst could exceed 6%. The NiO grains bond to each other in vermiform stacks, it is propitious to improve the catalytic activity because of the larger specific area.

Abstract: This paper elaborates the beneficiation methods of barite, flotation reagents and different types of mineral processing of barite.

Abstract: This study analyzes the effectiveness of a constructed wetland, including an improved distribution channel, to deal with the eutrophication of water in an urban lake; it was constructed at a conference center in Beijing, China. The improved distribution channel was designed to achieve two complementary objectives for the operation of a constructed wetland: (1) to delay the clogging of a constructed wetland with organic material and (2) to evenly distribute water in the constructed wetland. When backwashing of the improved distribution channel was done, backwashed water flowed onto the surface of the constructed wetland instead of into the sewage pipe networks to reduce the loss of water and supply nutritive matter for wetland plants. Two principles of the design were based on conserving water and on balancing the total phosphorus and were innovatively applied to guide the process design. After 5 years of operation, the eutrophicated water remediation system was found to have successfully improved the water quality of the constructed wetland by reducing total phosphorus, chemical oxygen demand with permanganate index, and total nitrogen and by efficiently delaying blockage of the constructed wetlands by organic materials.