广东交通职业技术学院（Guangdong Communication Polytechnic）是一所工科为主的综合性高等职业院校，2004年以“优秀”等级通过教育部高职高专人才培养水平评估，2013年以“优秀”等级通过首批国家骨干高职院校建设项目验收。 广东交通职业技术学院创办于1959年，1999年经教育部批准，由广东交通学校、广东省航运学校合并组建而成。 截至2017年1月，学校有广州市天河区、花都区两个校区，总占地面积1190多亩，有128个一体化多功能校内实训教学场所；设有9个二级学院，高职招生专业41个；有教职工总数804人，全日制学生13700多人。
To accurately evaluate the decay process,mechanism and influencing factors of anti-sliding performance of asphalt ultra-thin wear layer after opening to traffic,this study first used arc mold and its supporting wheel grinding mechanism to prepare arc-shaped ultra-thin wear layer specimens.Then,it carried out the accelerated loading test of asphalt ultra-thin wear layer specimens with four gradation types and three asphalt binder grades by driving wheel accelerated loading system.Finally,it scanned the specimens after a certain number of wheel loads by laser texture scanner.Combined with the test data,the macro and micro structure depth decay models of asphalt ultra-thin wear layer based on S-type function were established respectively,and the independent and coupling effects of each porosity and asphalt binder on skid resistance were analyzed based on grey correlation analysis.The experimental results show that the driving wheel accelerated loading system combined with the S-type function model can quantitatively evaluate and predict the evolution process of the performance of the asphalt ultra-thin wear layer.The porosity affects the early decay rate of the macro and micro structural depth of the ultra-thin wear layer.The larger the porosity,the greater the early decay rate of the macro and micro structural depth of the ultra-thin wear layer.The middle and late decay rate of macro-structure depth is more affected by the grade of asphalt binder.The higher the performance grade of asphalt binder,the slower the decay rate of macrostructure depth in the middle and late stages.Void ratio and asphalt binder grade have similar influence on the decay rate of the micro-structure depth of the ultra-thin wear layer in the middle and late stage.Therefore,when designing the anti-sliding performance of the ultra-thin wear layer,it is beneficial to select the open-graded ultra-thin wear layer mixture with large porosity for the anti-sliding durability of the pavement,and the performance grade of asphalt binder can be reasonably selected according to the traffic volume.
With the advent of the era of big data,with the emergence of massive data and explosive growth of information,the phenomenon of information overload is becoming increasingly serious.Personalized recommendation system is a powerful tool to solve information overload,and its core is recommendation algorithm,and collaborative filtering recommendation algorithm is the most widely used recommendation algorithm at present.By briefly summarizing the research progress of collaborative filtering recommendation algorithm,this paper summarizes and analyzes some key problems existing in the algorithm and related improvement schemes.Finally,it analyzes the problems to be solved and the future development direction of collaborative filtering recommendation algorithm.
With the rapid improvement of the performance of pure electric vehicle chips,the lack of heat dissipation has become the bottleneck of the development of electronic technology.When the heat flux density exceeds 100 W/cm~2,the traditional air cooling technology can not meet the heat dissipation demand.The double micro-channel heat sink is considered to be one of the best methods to improve the heat dissipation performance because of its large heat transfer area to volume ratio.In this paper,the optimization of the double micro-channel heat sink is carried out by using the response surface methodology in the field of pure electric vehicle chip heat dissipation.The results show that the optimized double micro-channel heat sink has better overall heat dissipation performance.Compared with the original size of the double micro-channel heat sink,the thermal resistance is reduced by 4.23%and 9.42%respectively.
