In order to deal with the complex association relationships between classes in an object-oriented software system,a novel approach for identifying refactoring opportunities is proposed.The approach can be used to dete...In order to deal with the complex association relationships between classes in an object-oriented software system,a novel approach for identifying refactoring opportunities is proposed.The approach can be used to detect complex and duplicated many-to-many association relationships in source code,and to provide guidance for further refactoring.In the approach,source code is first transformed to an abstract syntax tree from which all data members of each class are extracted,then each class is characterized in connection with a set of association classes saving its data members.Next,classes in common associations are obtained by comparing different association classes sets in integrated analysis.Finally,on condition of pre-defined thresholds,all class sets in candidate for refactoring and their common association classes are saved and exported.This approach is tested on 4 projects.The results show that the precision is over 96%when the threshold is 3,and 100%when the threshold is 4.Meanwhile,this approach has good execution efficiency as the execution time taken for a project with more than 500 classes is less than 4 s,which also indicates that it can be applied to projects of different scales to identify their refactoring opportunities effectively.展开更多
Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers bu...Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers buried directly. The result indicates that the heat exchanger makes the best use of structure of building,saves land,reduces the construction cost,and the heat exchanged is obviously more than exchangers buried directly. In winter condition,when W-shape pipe heat exchanger in pile foundation is 50 m deep and diameter is 800 mm,it transfers 1.2-1.3 times as large as the one of single U-shape buried directly at the flow rate of 0.6 m/s,whose borehole diameter is 300 mm. And in summer condition it does about 2.0-2.3 times as that of U-shape one.展开更多
为深入探究复合碳源的净化机理,以大口黑鲈(Micropterus salmoides)养殖系统为实验对象,设置2个处理组,分别添加玉米皮复合碳源和水稻杆复合碳源,对照组不添加复合碳源。通过平衡式孔隙水采样(Pore water equilibriums,Peeper)技术采集...为深入探究复合碳源的净化机理,以大口黑鲈(Micropterus salmoides)养殖系统为实验对象,设置2个处理组,分别添加玉米皮复合碳源和水稻杆复合碳源,对照组不添加复合碳源。通过平衡式孔隙水采样(Pore water equilibriums,Peeper)技术采集各组沉积物-水界面垂直剖面的原位水样,分析各组营养盐的垂直分布特征,并估算沉积物-水界面的交换通量,进而研究复合碳源对沉积物-水界面氮迁移转化的影响。结果表明:1)各组沉积物-水界面各营养盐均具有明显的垂直分布规律,除氨氮(NH_(4)^(+)-N)、总氮(TN)外,其他营养盐的浓度随深度增加呈下降趋势。2)在大口黑鲈养殖系统沉积物中,硝态氮(NO_(3)^(-)-N)是主要的内源释放营养盐;相比对照组,2组复合碳源均促进了沉积物中NH_(4)^(+)-N的释放;此外,玉米皮碳源减缓了NO_(3)^(-)-N、亚硝态氮(NO_(2)^(-)-N)和磷酸盐(PO_(4)^(3-)-P)的释放,水稻杆碳源的影响不显著。3)添加复合碳源促进了水体营养盐的去除,相比水稻杆碳源,玉米皮碳源对TN、PO_(4)^(3-)-P和化学需氧量(COD)的去除率更高,分别为73%、53%和48%。综上,添加复合碳源能够影响营养盐垂直分布特征和沉积物-水界面的扩散通量,其中玉米皮碳源可减缓沉积物中营养盐的释放,且具有较好的水体净化效果。展开更多
文摘In order to deal with the complex association relationships between classes in an object-oriented software system,a novel approach for identifying refactoring opportunities is proposed.The approach can be used to detect complex and duplicated many-to-many association relationships in source code,and to provide guidance for further refactoring.In the approach,source code is first transformed to an abstract syntax tree from which all data members of each class are extracted,then each class is characterized in connection with a set of association classes saving its data members.Next,classes in common associations are obtained by comparing different association classes sets in integrated analysis.Finally,on condition of pre-defined thresholds,all class sets in candidate for refactoring and their common association classes are saved and exported.This approach is tested on 4 projects.The results show that the precision is over 96%when the threshold is 3,and 100%when the threshold is 4.Meanwhile,this approach has good execution efficiency as the execution time taken for a project with more than 500 classes is less than 4 s,which also indicates that it can be applied to projects of different scales to identify their refactoring opportunities effectively.
基金Project(2006BAJ03A10) supported by the National Key Technology R&D Program of China
文摘Aiming at the ground-coupled source heat pump that possesses the shortcomings of occupying larger land,this article studies the heat exchanged of heat exchanger in piling,and compares it with common heat exchangers buried directly. The result indicates that the heat exchanger makes the best use of structure of building,saves land,reduces the construction cost,and the heat exchanged is obviously more than exchangers buried directly. In winter condition,when W-shape pipe heat exchanger in pile foundation is 50 m deep and diameter is 800 mm,it transfers 1.2-1.3 times as large as the one of single U-shape buried directly at the flow rate of 0.6 m/s,whose borehole diameter is 300 mm. And in summer condition it does about 2.0-2.3 times as that of U-shape one.
文摘为深入探究复合碳源的净化机理,以大口黑鲈(Micropterus salmoides)养殖系统为实验对象,设置2个处理组,分别添加玉米皮复合碳源和水稻杆复合碳源,对照组不添加复合碳源。通过平衡式孔隙水采样(Pore water equilibriums,Peeper)技术采集各组沉积物-水界面垂直剖面的原位水样,分析各组营养盐的垂直分布特征,并估算沉积物-水界面的交换通量,进而研究复合碳源对沉积物-水界面氮迁移转化的影响。结果表明:1)各组沉积物-水界面各营养盐均具有明显的垂直分布规律,除氨氮(NH_(4)^(+)-N)、总氮(TN)外,其他营养盐的浓度随深度增加呈下降趋势。2)在大口黑鲈养殖系统沉积物中,硝态氮(NO_(3)^(-)-N)是主要的内源释放营养盐;相比对照组,2组复合碳源均促进了沉积物中NH_(4)^(+)-N的释放;此外,玉米皮碳源减缓了NO_(3)^(-)-N、亚硝态氮(NO_(2)^(-)-N)和磷酸盐(PO_(4)^(3-)-P)的释放,水稻杆碳源的影响不显著。3)添加复合碳源促进了水体营养盐的去除,相比水稻杆碳源,玉米皮碳源对TN、PO_(4)^(3-)-P和化学需氧量(COD)的去除率更高,分别为73%、53%和48%。综上,添加复合碳源能够影响营养盐垂直分布特征和沉积物-水界面的扩散通量,其中玉米皮碳源可减缓沉积物中营养盐的释放,且具有较好的水体净化效果。
