To locate and quantify local damage in a simply supported bridge, in this study, we derived a rotational-angle influence line equation of a simply supported beam model with local damage. Using the diagram multiplicati...To locate and quantify local damage in a simply supported bridge, in this study, we derived a rotational-angle influence line equation of a simply supported beam model with local damage. Using the diagram multiplication method, we introduce an analytical formula for a novel damage-identification indicator, namely the diff erence of rotational-angle influence linescurvature(DRAIL-C). If the initial stiff ness of the simply supported beam is known, the analytical formula can be effectively used to determine the extent of damage under certain circumstances. We determined the effectiveness and anti-noise performance of this new damage-identification method using numerical examples of a simply supported beam, a simply supported hollow-slab bridge, and a simply supported truss bridge. The results show that the DRAIL-C is directly proportional to the moving concentrated load and inversely proportional to the distance between the bridge support and the concentrated load and the distance between the damaged truss girder and the angle measuring points. The DRAIL-C indicator is more sensitive to the damage in a steel-truss-bridge bottom chord than it is to the other elements.展开更多
In order to improve the reliability of the power system and provide uninterrupted power to the consumer, automatic reclosing (ARC) devices are often used in overhead power lines. On top of that, the condition of short...In order to improve the reliability of the power system and provide uninterrupted power to the consumer, automatic reclosing (ARC) devices are often used in overhead power lines. On top of that, the condition of short-circuit elimination or removal during ARC recloser depends on many random factors. In this article, the number of outages of 110 kV overhead lines in the Khangai region of Mongolia was studied, and the statistics of ARC device operation were compared with international standards. Also, from the works produced by scientists from foreign countries, the development level and innovative trends of ARC devices were compared and studied, and the opportunity to introduce them to Mongolia’s grid system was sought. Furthermore, the 110 kV transmission lines outage and the operation of the ARC devices installed in the Khangai region of Mongolia were studied. Hence, the average operation success rate of the ARC device in the last ten years was 76%. It was also found that the number of outages of 110 kV power lines is 8 per year on average, which is 2 - 3 times higher than the international norm. Eventually, the power grid scheme of the Khangai region, especially the Bulgan-Murun 110 kV distribution network, was modelled by Digsilent Powerfactory by including the features of Mongolia’s power transmission network, and the operation of the model was checked by the load flow function of the software.展开更多
[ Objective] The paper aimed to study the effects of Echinacea polysaccharide on secretion of IL-8mRNA by LPS-injured IEC-6 cells, in order to figure out the mechanism of EPS on injured cells. MethodI Total RNA was e...[ Objective] The paper aimed to study the effects of Echinacea polysaccharide on secretion of IL-8mRNA by LPS-injured IEC-6 cells, in order to figure out the mechanism of EPS on injured cells. MethodI Total RNA was extracted with TRlzon reagent. IL-8 mRNA was amplified by RT-PCR and detected by agar- ose gel electrophoresis. Furthermore, electrophoresis and image was analyzed. [ Result] The 50 μg/mL EPS could partially inhibit IL-8 mRNA level produced by -stimulated IEC-6; with the increasing concentration of EPS （200 and 500 μg/mL） , the inhibitory effect against IL-8 mRNA gradually enhanced. IEC-6 was pretreated by 50, 100,200 and 500 μg/mL EPS for ：24 h, then stimulated by 10 μg/ml 1,PS for 1 and 4 h, respectively. RT-PCR analysis showed that the expres- sion of 1L-8 mRNA induced by LPS was effectively inhibited by EPS; the inhibitory effect of EPS on expression of IL-8mRNA after stimulated by LPS for 4 h was more intense and the expression concentration was lower; the inhibitory rate at 4 h was higher than that at I h. [ Conclusion] EPS protected intestinal mucosa by inhibiting secretion of IL-8 mRNA by LPS-stimulated cells, and the inhibition of EPS was dependent to concentration and time.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51608245 and 51568041)Natural Science Foundation of Gansu Province(Nos.148RJZA026 and 2014GS02269)
文摘To locate and quantify local damage in a simply supported bridge, in this study, we derived a rotational-angle influence line equation of a simply supported beam model with local damage. Using the diagram multiplication method, we introduce an analytical formula for a novel damage-identification indicator, namely the diff erence of rotational-angle influence linescurvature(DRAIL-C). If the initial stiff ness of the simply supported beam is known, the analytical formula can be effectively used to determine the extent of damage under certain circumstances. We determined the effectiveness and anti-noise performance of this new damage-identification method using numerical examples of a simply supported beam, a simply supported hollow-slab bridge, and a simply supported truss bridge. The results show that the DRAIL-C is directly proportional to the moving concentrated load and inversely proportional to the distance between the bridge support and the concentrated load and the distance between the damaged truss girder and the angle measuring points. The DRAIL-C indicator is more sensitive to the damage in a steel-truss-bridge bottom chord than it is to the other elements.
文摘In order to improve the reliability of the power system and provide uninterrupted power to the consumer, automatic reclosing (ARC) devices are often used in overhead power lines. On top of that, the condition of short-circuit elimination or removal during ARC recloser depends on many random factors. In this article, the number of outages of 110 kV overhead lines in the Khangai region of Mongolia was studied, and the statistics of ARC device operation were compared with international standards. Also, from the works produced by scientists from foreign countries, the development level and innovative trends of ARC devices were compared and studied, and the opportunity to introduce them to Mongolia’s grid system was sought. Furthermore, the 110 kV transmission lines outage and the operation of the ARC devices installed in the Khangai region of Mongolia were studied. Hence, the average operation success rate of the ARC device in the last ten years was 76%. It was also found that the number of outages of 110 kV power lines is 8 per year on average, which is 2 - 3 times higher than the international norm. Eventually, the power grid scheme of the Khangai region, especially the Bulgan-Murun 110 kV distribution network, was modelled by Digsilent Powerfactory by including the features of Mongolia’s power transmission network, and the operation of the model was checked by the load flow function of the software.
基金Supported by National Natural Science Foundation of China(31472230)Natural Science Foundation of Hebei Province(C2014407068)Project of Hebei Department of Science and Technology(14966610D)
文摘[ Objective] The paper aimed to study the effects of Echinacea polysaccharide on secretion of IL-8mRNA by LPS-injured IEC-6 cells, in order to figure out the mechanism of EPS on injured cells. MethodI Total RNA was extracted with TRlzon reagent. IL-8 mRNA was amplified by RT-PCR and detected by agar- ose gel electrophoresis. Furthermore, electrophoresis and image was analyzed. [ Result] The 50 μg/mL EPS could partially inhibit IL-8 mRNA level produced by -stimulated IEC-6; with the increasing concentration of EPS （200 and 500 μg/mL） , the inhibitory effect against IL-8 mRNA gradually enhanced. IEC-6 was pretreated by 50, 100,200 and 500 μg/mL EPS for ：24 h, then stimulated by 10 μg/ml 1,PS for 1 and 4 h, respectively. RT-PCR analysis showed that the expres- sion of 1L-8 mRNA induced by LPS was effectively inhibited by EPS; the inhibitory effect of EPS on expression of IL-8mRNA after stimulated by LPS for 4 h was more intense and the expression concentration was lower; the inhibitory rate at 4 h was higher than that at I h. [ Conclusion] EPS protected intestinal mucosa by inhibiting secretion of IL-8 mRNA by LPS-stimulated cells, and the inhibition of EPS was dependent to concentration and time.
