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Steel–concrete composite girder rigid frame bridges with V-shaped piers are a new type of bridge structure. Based on the traditional composite continuous beam bridge, part or all of the vertical piers are changed into V-shaped piers. This special structure makes them have the mechanical characteristics of both composite continuous beams and V-shaped piers. In this paper, the finite element model of the first steel–concrete composite continuous beam V-pier rigid frame bridge in China is established by simulation software, the construction process of the bridge is simulated, and the stress and deflection of the bridge in each construction stage are studied. At the same time, the stress of the completed bridge model considering the construction stage is compared with that of the completed bridge model without considering the construction stage. It is found that the stress difference between the two concrete slabs is as high as 2.7 MPa. The results show that the stress state of the bridge is greatly affected by the construction process. This study can provide guidance for the design and construction of such bridges, which is of great significance. [ABSTRACT FROM AUTHOR]

Changes in loading position have a significant impact on the stress field of each vulnerable area of an orthotropic steel deck (OSD). The arc opening area of the diaphragm and the connecting area between the U-rib and the diaphragm under the moving load are prone to fatigue cracking. By comparing the stress responses under different methods, the hot spot stress (HSS) method is used as the main stress extraction method in fatigue performance evaluation. The control stress of fatigue cracking was analyzed by comparing the direction of the principal stress field with the crack direction in this experiment. According to the stress amplitude deviation under the biaxial stress state, a set of methods for evaluating the effects of in-plane biaxial fatigue was developed. An improved luffing fatigue assessment S–N curve was applied to analyze the fatigue life of the diaphragm's arc opening area. The results show that when the moving load is exactly above the connection of the deck and the web of the U-rib on one side, it is in the most unfavorable position in the transverse direction, and the diaphragm is mainly under the in-plane stress state. The longitudinal range of the stress influence line of the arc opening is approximately twice the diaphragm spacing. Two to three stress cycles are caused by one fatigue load. Fatigue crack control stress is the principal stress tangential to the arc opening's edge in this area. The normal direction of the principal stress in the model test is roughly consistent with the crack initiation direction. The variation in the stress amplitude deviation in this area is caused by changes in the action position of the moving load. When the moving load is at a certain distance from the involved diaphragm, it is reduced to zero, implying that the in-plane fatigue effect is the greatest in this area. [ABSTRACT FROM AUTHOR]

Objective: To study the chemical constituents of Memorialis hirta., Method: Compounds were isolated and purified by multiple methods, and their structures were identified based on physicochemical property and spectrum data., Result: 12 compounds were isolated from ethyl acetate from 95% ethanol extracts of M. hirta, they were isorhamnetin (1), kaempferol (2), quercetin (3), isorhamnetin-3-O-alpha-L-rhamnopyranoside (4), kaempferol-3-O-alpha-L-rhamnopyranoside (5), isorhamnetin-3-O-beta-D-glucopyranoside (6), kaempferol-3-O-beta-D-glucopyranoside (7), quercetin-3-O-alpha-L-rhamnopyranoside (8), quercetin-3-O-beta-D-glucopyranoside (9), isorhamnetin-3-O-rutinoside (10), kaempferol-3-O-rutinoside (11) and quercetin-3-O-rutinoside (12), respectively., Conclusion: All compounds were obtained from the genus Memorialis for the first time.

Objective: To study the chemical constituents of Androsace umbellata., Method: Many chromatography means were used in separation and purification, and the structures of all compounds were identified by the means of spectroscopic analysis and physico-chemical properties., Result: 10 compounds were elucidated as kaempferol 3-O-(3-O-acetyl-)-alpha-L-rhamnopyranoside(1), kaempferol 3-O-(2-O-acetyl-)-alpha-L-rhamnopyranoside(2), kaempferol 7-O-alpha-L-rhamnopyranoside(3), kaempferol 3-O-alpha-L- rhamnopyranoside(4), kaempferol 3-O-beta-D-glucopyranoside(5), kaempferol 3-O-(3-O-acetyl-)-a-L-rhamnopyranosyl-7-O-alpha-L- rhamnopyranoside(6), kaempferml 3-O-(4-O-acetyl-)-alpha-L-rhamnopyranosyl-7-O-alpha-L-rhamnopyranoside(7), quercetin 3-O-alpha-L- rhamnopyranoside(8), quercetin 3-O-beta-D-glucopyranoside(9) and myricetin 3-O-beta-D-glucopyranoside (10), respectively., Conclusion: All compounds were obtained from the title plant for the first time.