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941.
Yi‐Bing Lin Ren‐Huang Liou Chun‐Ting Chang 《Wireless Communications and Mobile Computing》2015,15(4):629-638
In long‐term evolution, the service area is partitioned into several tracking areas (TAs), which comprise one or more cells (the radio coverages of base stations). The TAs are grouped into TA list (TAL). When an incoming call arrives, the network attempts to connect to the user equipment (UE) by paging the cells in the UE's TAL, which may incur large paging traffic that significantly consumes the limited radio resources. To resolve this issue, this paper proposes a dynamic paging scheme that determines the paging sequence of cells in real time according to the UE movement and call behavior. We compare the performance of the dynamic paging with that of the previously proposed Cell‐TA‐TAL (CTT) paging. Our study indicates that the dynamic paging outperforms the CTT paging when movement pattern is regular and the UE moves frequently. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
942.
Jianping Zhang Yuying Du Helen Wu Weiguo Pan Jianxing Ren Danmei Hu 《The International journal of environmental studies》2013,70(3):344-359
The PM10 collection efficiency of a wire-cylinder electrostatic precipitator (ESP) was studied by means of a developed mathematical model, including the multi-field coupling between the gas flow field, the particle dynamic field and the electric field, and applying the Deutsch–Anderson Equation. The diffusion charging mechanism was considered due to the diameter range of PM10. The investigated variables were the applied potential, the gas velocity and the particle distribution. Numerical results indicate that the diffusion charging has significant influence on PM10 removal performance and the effect is more obvious with the decreasing diameter, and that the PM10 collection efficiency increases with the increasing applied potential and the increment of collection efficiency is more significant at lower voltage. Moreover, as the gas velocity at inlet decreases, collection efficiency of PM10 will increase. Finally, the overall efficiency increases with increasing the mean diameter of particle distribution. The research results can provide theoretical and technical references for the design of novel ESP aiming at economy and environment protection. 相似文献
943.
One important reason for low hydrogen production from protein wastewater is due to the native folded conformation of protein. In this study the enhancement of bio-hydrogen production from protein wastewater by altering protein conformation via pretreatment was reported. Firstly, the effect of different pretreatment methods (acid, alkali, heat, and ultraviolet) on hydrogen production from synthetic protein wastewater was compared. The hydrogen production from the ultraviolet pretreated wastewater was 111.3 mL/g-protein, which was 3.79-, 3.73-, 3.54-, and 1.36-fold of that from the unpretreated (blank), acid, alkali, and heat pretreated wastewater, respectively. Then, the reasons for ultraviolet pretreatment showing significantly higher hydrogen production than other pretreatments were investigated. It was found that all pretreatments did not cause the cleavage of peptide bond, but the ultraviolet one caused much greater damage of hydrogen bonding networks and unfolding of protein. Thus, during anaerobic fermentation much higher protease activity and protein utilization were observed, which resulted in the bio-hydrogen production being remarkably improved. Further studies indicated that the photo-oxidization of aromatic residues in protein was not the reason for ultraviolet pretreatment remarkably improving bio-hydrogen production. Finally, the application of ultraviolet pretreatment to enhance hydrogen production from real protein wastewater was testified. 相似文献
944.
945.
文章针对腰线在高层住宅立面设计中的广泛运用,探讨了腰线的起源及在高层住宅立面设计中的作用,并对高层住宅立面腰线的设计做出了一定的探索。 相似文献
946.
947.
Synthesis of a perfluorooctanoic acid molecularly imprinted polymer for the selective removal of perfluorooctanoic acid in an aqueous environment 下载免费PDF全文
Perfluorooctanoic acid (PFOA) contamination in the environment is a global problem. The aqueous phase is the main medium for PFOA because of its moderate solubility. Adsorption is a feasible way to remove PFOA because of its chemical and biological stability. In this study, a new type of molecularly imprinted polymer (MIP) for the selective adsorption of PFOA in aqueous solutions was synthesized by the precipitation polymerization method with PFOA as the template molecule after optimization. The adsorption kinetics and isotherms of the MIP adsorbent toward PFOA were studied, and the effects of the pH and cations on the adsorption were investigated with batch experiments. The results show that acrylamide (AAM) was the best functional monomer, and the optimal molar ratio of PFOA to AAM to ethylene glycol dimethacrylate (crosslinker) was 1:6:25. The optimized MIP adsorbent had a high affinity for PFOA, and the uptake percentage by the MIP adsorbent was 1.3–2.5 times that of the nonimprinted polymer (NIP) when PFOA existed alone. A maximum PFOA sorption capacity of 5.45 mg/g based on the Langmuir isotherm model was achieved with the MIP adsorbent. The MIP adsorbent exhibited a high selectivity for PFOA over competitive compounds (other perfluorinated alkyl carboxylic and sulfonic acids), whereas the NIP did not. Approximately 90% of the PFOA in the mixture was removed by the MIP adsorbent; this was 18 times that of the NIP. Moreover, the regenerability of the MIP adsorbent was confirmed in five sequential adsorption–desorption cycles without a significant reduction in the PFOA uptake. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43192. 相似文献
948.
Improving thermo‐oxidative degradation resistance of bamboo fiber reinforced polymer composites with antioxidants. Part II: Effect on other select properties 下载免费PDF全文
The first of this two‐article study showed that the addition of antioxidants can significantly improve the thermo‐oxidative resistance of bamboo fiber reinforced polypropylene composites (BFPCs). In this article, the effect of antioxidants on water absorption, thermal stability, crystallinity, and the dynamic mechanical properties of the composites were investigated. The results showed that the addition of antioxidants resulted in a slight increase in water absorption, but this increase can be reduced by controlling the ratio of the primary and secondary antioxidants. The glass transition temperature (Tg) of composites also slightly increased. However, the effects of antioxidants on the crystallinity as well as other thermal properties of BFPCs were small or even insignificant. The different combinations, ratios, and the adding amounts of antioxidants show tiny differences for all these properties. As a whole, the addition of minor antioxidants in the bamboo fiber (BF) polymer composites will not produce obvious negative effects on their overall performances. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44199. 相似文献
949.
Improving thermo‐oxidative degradation resistance of bamboo fiber reinforced polypropylene composite with antioxidants. Part I: Screening of antioxidants 下载免费PDF全文
In this study, the effect of antioxidant application (applied in different combinations, ratios and contents) on the thermo‐oxidative degradation resistance of bamboo fiber polypropylene composites (BFPCs) were investigated, with oxidative induction time (OIT), weight loss, surface color, and flexural mechanical properties as the main indicators for evaluation. The results showed the addition of antioxidants could greatly increase the OIT and reduce the weight loss and color change of the composites after 900 h of thermal weathering. Meanwhile, the flexural mechanical properties were little affected or even slightly improved. The combination of 1076 and DLTP antioxidants at a ratio of 2:1 and 0.2 wt % content was found to exhibit the best thermal oxidation resistance with respect to the OIT, mechanical properties and cost. Our study indicate that the OIT can serve as a simple and quick indicator for the evaluation of thermo‐oxidative resistance of BFPC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44198. 相似文献
950.
Poly[6‐(2,6‐bis(1′‐methylbenzimidazolyl)pyridin‐4‐yloxy)hexyl acrylate] (PBIP) and its terbium (III) complex (PBIP‐Tb3+): Homopolymerization,optical, and magnetic performance 下载免费PDF全文
Poly[6‐(2,6‐bis(1′‐methylbenzimidazolyl)pyridin‐4‐yloxy)hexyl acrylate] (PBIP) and its terbium complex (PBIP‐Tb3+) were prepared and characterized by 1H NMR and FT‐IR. The optical properties of PBIP‐Tb3+ complex were characterized by UV–vis spectroscopy and fluorescence spectroscopy. Both polymer PBIP and PBIP‐Tb3+ complex show good thermal stability. The magnetic property of PBIP‐Tb3+ complex was measured as a function of temperature (5–300 K) at 30 kOe and as a function of an external field (?50 to 50 kOe) at 5 K. Magnetic hysteresis loop of PBIP‐Tb3+ complex at 5 K shows typical “S” shape and PBIP‐Tb3+ complex is soft ferromagnetic. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44249. 相似文献