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Related Vehicle Routing Problem is another form of Vehicle Routing Problem. RVRP also belongs to NP-Hard with a wide range of application areas and major economic value. The research based on single distribution center RVRP with road capacity static constraint, to build a model of single distribution RVRP and propose a kind of chaos genetic algorithm to solve this problem, with experiments verify the feasibility and effectiveness of the algorithm. © (2013) Trans Tech Publications, Switzerland. Source


Jian W.,South China Agricultural University | Jian W.,Xiamen Ocean Vocational College | Sun Y.,South China Agricultural University | Huang H.,South China Agricultural University | And 7 more authors.
Carbohydrate Polymers | Year: 2013

To study the preparation and separation of Konjac oligosaccharides, Konjac Glucomannan was degraded by the combination of γ-irradiation and β-mannanase, and then the degradation product was separated by ultrafiltration. To our interest, for most of Konjac oligosaccharides obtained by this method, the molecular mass was lower than 2200 Da. In addition, the 1000 Da molecular weight cut off membrane could effectively separate the Konjac oligosaccharides. In conclusion, the combination of γ-irradiation and β-mannanase was an efficient method to obtain Konjac oligosaccharides, and the oligosaccharides of molecular mass lower than 1000 Da could be effectively separated by ultrafiltration. © 2012 Elsevier Ltd. Source


Wu C.,Fujian Agriculture and forestry University | Peng S.,Guangzhou City Polytechnic | Wen C.,Fujian Agriculture and forestry University | Wang X.,Fujian Agriculture and forestry University | And 3 more authors.
Carbohydrate Polymers | Year: 2012

A series of novel edible blend films of konjac glucomannan (KGM) and curdlan were prepared by a solvent-casting technique with different blending ratios of the two polymers. The Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), etc. were used to characterize the change of structure and properties of blend films. The results showed that the strong intermolecular hydrogen bonds took place between KGM and curdlan. And the interaction of the blend film was much greater than that of the others when the KGM content in the blend films was around 70 wt% (KC7), resulting in excellent miscibility. The conclusion of the electron tensile testing analysis indicated that the blend film KC7 showed the maximum tensile strength (42.93 ± 1.92 MPa). In addition, the blend films displayed excellent moisture barrier properties, which had a potential application in the food field. © 2012 Elsevier Ltd. All rights reserved. Source


Hu C.,China Electronic Product Reliability and Environmental Testing Research Institute | Zhou L.,Guangzhou City Polytechnic
Proceedings of the Electronic Packaging Technology Conference, EPTC | Year: 2014

As an important packaging material, much work has been done in an attempt to improve DGEBA epoxy resins to be used in electric industry. In order to improve heat resistance, the cross-linking density of epoxy resins has been attempted to increase, or rigid groups have been introduced to copolymerize with epoxy resin. However, these methods have been confirmed that they will induce friability. In addition, as Si-O-Si bonding is more flexible than C-C bonding, siloxane oligomer is introduced to the matrix to improve toughness of epoxy resins, but the glass transition temperature (Tg) becomes lower by reason of low compatibility between epoxy resin and siloxane. Moreover, the pure epoxy resins are flammable. It is worth notice that halogen-containing resins are considered to limit the use by reason that they will release toxic gases while heating. Phosphorus-containing epoxy resins could substitute for halogen-containing resins for the use of flam-retardant. The introductions of phosphoric ethers, DOPO or its derivatives to the matrix have been reported. Such methods are confirmed to improve flam-retardant with epoxy, but The decreasing of heat resistance and toughness can't be ignored when too much phosphorus is in the resins. From the above, it is known that present achievements can improve the property of epoxy resins at one side, but they can not improve or at least keep the other properties. In this study, a kind of novel silicon, phosphorus-containing hybrid material was prepared and it could be used as the modifier of DGEBA epoxy resins. The thermal stability, toughness and flam-retardant of the modified resins were all improved. For one thing, the hybrid material was mainly composed of polysiloxane, and the Si-O-Si chains in the matrix would improve toughness for the resins. For another, the hybrid material contained a lot of hydroxyl groups in the structure. The compatibility with epoxy resins and the modifier is good. The Si-OH groups in the hybrid material could react with the hydroxyl groups in DGEBA when the resins were cured. The heat resistance was improved on account of higher cross-linking density of the resins. What's more, phosphorus-containing groups were introduced in the hybrid material. P and Si could both act to exhibit the considerable synergistic effect on flam-retardant even though the weight of P was low. In this paper, the thermal, mechanical and flammable properties of the cured samples were investigated in detail by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), as well as tensile, impact and limited oxygen index (LOI) testing. The result showed that the hybrid modified epoxy resins exhibited good thermal stability, toughness and flam-retardant property. With the ratio m(DGEBA): m(SPCH)=100: 25, Tg of the modified sample was 49.35 °C higher than that of the pure sample, and LOI was raised from 21.5 to 29.8. The char yield of E-25 at 800°C reached to 37.8 %, which compared to 12.9 % of the pure sample. But the toughness of E-25 was not so prominent if compared with E-15. The impact stress of sample E-15 reached to 24.1 kJ·m-2. For all modified samples, the tensile strengths were all basically maintained. SEM micrographs of the fracture surfaces indicated that these modified resins were homogeneous and tough. In the practical application, the different ratios of the modifier in epoxy resin were chosen with actual demand. © 2014 IEEE. Source


Zhang Y.-H.,Guangdong Academy of Agricultural Sciences | Huang L.-H.,Guangzhou City Polytechnic | Wei Z.-C.,Guangdong Academy of Agricultural Sciences
European Food Research and Technology | Year: 2014

The effects of additional heat-induced fibrils on the viscosity and gel strength of rice bran albumin (RBA) were studied. The structure and morphology of the fibrils were strongly affected by extent of heating time. The mean contour length and particle size of RBA fibrils increased with increasing heating time. The conversion of RBA monomers into linear aggregations at pH 2.0 and 90 °C increased with increasing heating time and protein concentration. Adding mature fibrils to RBA solutions can modify the structural properties and make this system rather complex. Rheological results showed that adding fibrils could promote solution thickening and gel hardening behavior and result in a significant increase in solution viscosity and gel strength. Interestingly, adding the longer heating time fibrils exhibited a higher viscosity values and elastic modulus. Significant difference in gel structure obtained by scanning electron microscopy between fibrils/RBA and RBA was observed. The former has more loose mesh structure than the latter. These results would be of great importance for understanding the physicochemical properties of RBA fibril assembly. © 2014, Springer-Verlag Berlin Heidelberg. Source

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