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The rapid repair of concrete pavement under severe cold environment requires the repair materials to have high early strength and high bond strength with concrete. Using magnesium phosphate cement (MPC) with high early strength to prepare rapid repair materials is beneficial for achieving rapid repair of concrete pavement under non curing conditions in the winter. The effects of magnesium phosphorus ratio (M/P), boron magnesium ratio (B/M), and water cement ratio (W/C) on bond strength between MPC mortar and ordinary Portland cement concrete (OPC) in severe cold environment were studied, and the interface bonding mechanism were analyzed. The results show that M/P 4 ~ 5, B/M 0.02 ~ 0.03, and W/C 0.12 ~ 0.14 are more conducive to improve bond strength between MPC mortar and OPC in severe cold environment. The 3 h bond strength between MPC mortar and OPC can exceed 2.5 MPa, meeting the requirements for rapid repair of concrete pavement in severe cold environment. [ABSTRACT FROM AUTHOR]

In order to solve problems of gas overrunning in No.735 Coal Mining Face of Dahuangshan Mine, a gas drainage technology with separated sources was put forward based on analysis of main sources of gas emission of the coal mining face, that is, gas in goaf is drainaged directly through crossing borehole by optimizing drainage pipelines, so as to realize gas drainage in goaf and mining seam separately. The application results show that gas volume fraction in air return flow is 0.36%-0.46%, gas volume fraction in upper corner is 0.4%-0.6%, and gas drainage average rate is 59.17% after the gas drainage conducted with separated sources.

The performance of the penetration system and the multi-stress creep recovery test (MSCR) were carried out for different PPA composite SBS and SBR modified asphalt binders to evaluate the storage stability, road performance and rheological properties of the modified asphalt. The laboratory test verified the conventional road performance of PPA compound polymer modified asphalt mixture and its stability under high temperature and heavy load. The results show that the incorporation of 1.0% ~1.25% polyphosphoric acid can significantly improve the high temperature performance of matrix asphalt and low-dose SBS and SBR modified asphalt,and improve the high temperature rheological properties and thermal storage stability of polymer modified asphalt. The PPA compound SBR modified asphalt mixture has the best low temperature performance. PPA compounded SBS modified asphalt mixture has better resistance to permanent deformation and water stability better than 5% SBS modified asphalt mixture. For asphalt roads with severe requirements on high temperature and heavy load, it is recommended to adopt PPA compound SBS scheme. [ABSTRACT FROM AUTHOR]

The preparation process of nano-montmorillonite (OMMT) and SBS modified asphalt was studied by orthogonal test. Through the three index tests of modified asphalt, the effects of each factor on the high and low temperature performance and thermal storage stability were analyzed. The results show that the content of SBS and shear temperature have significant effects on the high and low temperature performance of modified asphalt. OMMT has significant effects on the high temperature performance and thermal storage stability. The above three significant factors shall be controlled during the preparation of OMMT-SBS modified asphalt. [ABSTRACT FROM AUTHOR]

The Chinese china represented in the eighteenth-century English poetry is the focus of both men and women's aesthetic appreciation and desire. Men reduce women to the object of their aesthetic appreciation and desire by drawing an analogy between china and women and by objectifying women into china, whereas women, by means of requesting, seeing and consuming china, foreground their subjectivity and value by projecting their aesthetic appreciation and desire onto the beautiful and delicate china. In addition, women dissolve and transcend the binary opposition between "earthenware/man" and "china/women" constructed by the male-centered discourse through endowing china with multi-gender and multi-identity. The end of the eighteenth century witnesses the fall of Chinese china in English society; hence it has lost its focal position and been replaced by other materials as the above-mentioned focus. [ABSTRACT FROM AUTHOR]