Advanced Materials Research Vols. 884-885

Abstract: 2-mercaptobenzothiazole was used to deal with natural rubber (NR) latex to prepare constant viscosity natural rubber (CV-NR) in this research. The dynamic viscoelastic behavior of CV-NR of raw rubber, rubber compound and vulcanized rubber was studied through strain and frequency scanning on rubber processing analyzer, and then it was compared with the response curve of NR.

Abstract: The General Status of the Refractory Metal was Reviewed Including its Characteristics and Application. the New Technology Research of Directly Prepared Refractory Metal from Refractory Metal Oxide was Discussed. FFC, OS and SOM Methods were Mainly Introduced. at the same Time, their Advantages and Disadvantages and the Difference between each other were also Pointed out. the Development Trends and Application Prospect of the Refractory Metal in Future were Prospected.

Abstract: The preparation of complex PZT with high d₃₁ piezoelectric performance, which is used to the energy harvesting cantilever in vibration mode, is discussed in this paper. The Si/SiO₂/Cr/Au/PT/PZT/PT structure base on (100) silicon crystallographic is growth through a PT transition layer before coating Sol-gel PZT film, which is in favor of the PZT film polarization processing in d₃₁ shear mode. It is shown that the PZT film present the perovskite phase after optimize annealing at 700°C by XRD analysis. Piezoelectric properties test indicated that the PZT film has the coercive field at 23kV/cm and the remnant polarization is 60μC/cm². The silicon-based cantilever with complex PZT film fabricated by MEMS technology is also given in the paper.

Abstract: In hollow-core optical fibers, surface mode is one most important reasons causes fiber loss. In order to suppress surface mode loss, simulations of the designed hollow-core optical fibers have been made numerically using full vector finite element method, and the light intensity distributions are in the different core transversal radius is obtained. Analysis results show that both the enlargement of core radius and using fusing transversal method lead into the core holeare more helpful to suppress surface mode loss. This conclusion may provide a basis for small duty cycle (f < 85%) hollow-core optical fibers fabrication the theoretically. Keywords:hollow-corephotonic band-gap fiber (HC-PBF),finite element method (FEM), surface mode loss, core transversal radius, core intersected method

Abstract: Friction Stir Welding (FSW) is a new type of solid-state connection which can reduce structural weight significantly. In this paper, fatigue tests and finite element analysis were employed to study fatigue properties and residual stresses of aerial aluminum alloy 2524-T3 FSW joint. The residual stresses in FSW joint were obtained by a nonlinear direct coupled-field finite element analysis. On the basis of finite element analysis results, the fatigue life of FSW joint was estimated. It is verified that the analytic and estimated results agree with that of experiment.

Abstract: It is well-known that sharkskin surface has the effect of inhibiting the occurrence of turbulence and reducing the wall resistance, however, the drag reduction mechanism has developed into an urgent problem to be resolved now. According to the actual circumstance, for purpose of obtaining the best drag-reducing efficiency, the biomimetic sharkskin micro-grooved surface is designed according to the relevant literatures and research achievements, and numerical simulation of the micro flow field on the biomimetic sharkskin surface is carried out comprehensivley, which has the important significance to explain the drag reduction mechanism.

Abstract: Using lower-convected Maxwell constitutive model, the control equation of the steady flow of viscous-elastic fluid in the eccentric annulus with inner rod moving axially in the bipolar coordinates system is established, and discreted by control-volume method, the velocity profile is solved by ADI methods, which lays theory basis for further analyzing the stress field and the reason of pumping rod eccentric wear. The result shows: eccentric ratio is the most important factor to the velocity profile.

Abstract: Jade perch (Scortum barcoo) meat nutrition analysis and evaluation was carried out in this paper, results showed that: the protein content, fat content and total amino acid content of Jade perch are 18.4%, 9.0% and 19.99% respectively. As a balanced amino acid combination, it contains a variety of amino acids necessary for the meat, glutamic acid content of up to 3.10%, delicious amino acids in the total amino acid content 7.64%. Jade perch has a lower fat content, but rich in unsaturated fatty acids, DHA content is 3.36%, rich in Ca, Fe, Zn, Se and other trace elements, in the jade perch, the heavy metals and other toxic substances analysis showed that they are in line with national health and safety standards, the Jade Perch is a good quality, high nutritional value of edible fish.

Abstract: The aim was to identify codon usage bias between the newly comfirmed Salmonella pullorum outer membrane protein C (ompC) gene (GenBank accession No. CP003047) and that of other 21 reference Enterobacteriaceae ,and we performed comparative analysis of the codon usage bias among different organisms by a series of bioinformatics softwares The apparent codon usage bias in the 22 ompC were indicated by the codon adaptation index (CAI), effective number of codons (ENc) and the value of G+C content at the 3rd codon position ( GC3s).The Enc-plot revealed that these outer membrane protein C genes are subject to GC compositional constraints.The correlation analysis with other four organisms implied that codon usage pattern of E.coli is similar to Salmonella pullorum OmpC .

Abstract: Thirteen strains of lactic acid bacteria were isolated from the local traditional fermented yoghurt. One of them showed the highest GABA-producing ability in MRS broth with 1% L-glutamate. The strain was identified Streptococcus thermophilus QYW-LYS1 based on morphological characteristics and 16S rDNA sequence determination. The single factor design was applied to optimize culture conditions. The optimal initial cell density, temperature and reaction time were 0.2OD·mL^-1, 34°C and 72h respectively. Under the optimized reaction conditions, the production of GABA was 2.905g/L.The result may contribute to the development of traditional fermented dairy product with functional properties.