Heavy tamping is one of the important methods for ground treatment. But the vibration is often a problem that restricts the application during heavy tamping. On the other hand, as an instant impact load with controlla...Heavy tamping is one of the important methods for ground treatment. But the vibration is often a problem that restricts the application during heavy tamping. On the other hand, as an instant impact load with controllable energy, heavy tamping is a good test in situ for the study of soil dynamics. With the analysis in the field of frequency, deductive method for medium effecting function and excitation function of heavy tamping is put forward in this paper.展开更多
The fundamental solution to dynamic elastic differential equation after the Laplace transformation, which was obtained by Cruse and Rizzo, has been utilized to solve the boundary integral equation formulated by the we...The fundamental solution to dynamic elastic differential equation after the Laplace transformation, which was obtained by Cruse and Rizzo, has been utilized to solve the boundary integral equation formulated by the weighted residual method. The boundary element method has been applied to dealing with the heavy tamping problem. As the elasticity modulus of soil is gradually increased after each tamping, and the loading modulus and unloading modulus are quite different, residual deformations can be finally obtained for each tamping. This is a method of nonlinear elastic analysis. The relationship of hammer velocity and falling distance for heavy tamping within liquid has been derived, so providing a theoretical background for heavy tamping under water.展开更多
Backfill hydraulic support is the key equipment in achieving coal mining and solid backfilling simultaneously in solid backfill mining technology.Based on the summary and analysis of main types,basic structural proper...Backfill hydraulic support is the key equipment in achieving coal mining and solid backfilling simultaneously in solid backfill mining technology.Based on the summary and analysis of main types,basic structural properties and filed application of backfill hydraulic support,this work has firstly proposed the basic principle of backfill hydraulic support optimization design and provided the method of optimal design of key structural components,like four-bar linkage,rear canopy and tamping structure;the method is further elaborated as changing hinging position of upper bar to optimize four-bar linkage,by lengthening or shortening the rear canopy to optimize length ratio of canopy;and by changing length and hinging position of tamping structure as well as suspension height of backfill scrape conveyor to realize optimization of tamping structure.On this basis,the process of optimal design of backfill hydraulic support is built.The optimal design case of ZC5200/14.5/30 six columns-four bar linkage used in 7203 W workface of Zhaizhen Coal Mine shows that the backfill properties like horizontal roof gap,vertical horizontal gap,tamping angle and tamping head gap are improved obviously through optimizing four-bar linkage,canopy length and tamping structure according to the optimal design method proposed in this work.展开更多
分析高表达肿瘤抗原-线粒体蛋白12(tumor antigen-associated mitochondrial protein 12,TAMP12)对肿瘤细胞增殖和凋亡的影响,探讨该蛋白的生物学功能。构建pcDNA3.1-TAMP12载体转染的人肝癌细胞株(SMMC-7721),获得稳定高表达TAMP12的SM...分析高表达肿瘤抗原-线粒体蛋白12(tumor antigen-associated mitochondrial protein 12,TAMP12)对肿瘤细胞增殖和凋亡的影响,探讨该蛋白的生物学功能。构建pcDNA3.1-TAMP12载体转染的人肝癌细胞株(SMMC-7721),获得稳定高表达TAMP12的SMMC-TAMP12细胞株.通过Realtime-PCR检测TAMP12 mRNA表达含量,激光扫描共聚焦显微镜观察双色荧光标记蛋白的表达和亚细胞定位。采用MTT法检测细胞的增殖速率,并应用不同浓度的5-氟尿嘧啶(5-Fluoron-racil,5-FU)处理肿瘤细胞,检测细胞的生长周期和凋亡,以及凋亡相关酶的活性。结果显示转染细胞中mRNA和蛋白呈稳定高表达,定位于细胞线粒体中。TAMP12具有促进肿瘤细胞增殖作用,抑制细胞凋亡作用,并与胱天蛋白酶3/8/9(caspase3/8/9)的活性有关。展开更多
It is difficult to distinguish tamping coke and top charging coke by conventional testing methods, such as cold strength, abrasion resistance, reactivity and strength after reaction. Some of tamping coket s properties...It is difficult to distinguish tamping coke and top charging coke by conventional testing methods, such as cold strength, abrasion resistance, reactivity and strength after reaction. Some of tamping coket s properties were even bet-ter than those of top charging coke, hut from practical using effects of blast furnace, tamping coke was not as good as top charging coke. The reaction conditions were featured as high temperature, high alkali condition, intense reac-tion atmosphere and short time. Distribution of porosity in profile, microstructure and slag forming property of ash were analyzed and following conclusions were obtained. After alkali-rich reaction, there were obvious differences be- tween top charging coke and tamping coke in microstructure, The porosityts unevenness of tamping coke was greater than those of top charging coke, and tamping coke was with less and big pores in out space and inner part was dense with more throughout pores. After phase diagram and microstructure analysis, it could he obtained that ash forming characteristics of top charging coke were better than those of tamping coke, and top charging coke＇ s pores were blocked more seriously than those of tamping coke. From analysis of tuyere samples, it could be found that calcium content of ash in coke＇s pores was small and it should belong to coke＇s inherent ash; kalium （wκ =28%） was unusu-ally high in coke. so the situation of high alkali was close to real blast furnace reaction condition.展开更多
This work details new insights into the in-process densification mechanism of cold spray Al coatings. The results show a trend counter to common observations: coating plastic deformation levels and coating density dec...This work details new insights into the in-process densification mechanism of cold spray Al coatings. The results show a trend counter to common observations: coating plastic deformation levels and coating density decreases with an increase in particle impact velocity. A lower particle impact velocity and the consequent lower deposition efficiency(DE) results in greater tamping energy per unit volume of deposit,which is the primary reason for the observed trend. This is the first time that DE has been shown to have a non-linear impact on the density of a cold spray coating, with particle in-process tamping being the primary mechanism for coating densification.展开更多
The rapidly increasing scale of data warehouses is challenging today＇s data analytical technologies. A con- ventional data analytical platform processes data warehouse queries using a star schema -- it normalizes the...The rapidly increasing scale of data warehouses is challenging today＇s data analytical technologies. A con- ventional data analytical platform processes data warehouse queries using a star schema -- it normalizes the data into a fact table and a number of dimension tables, and during query processing it selectively joins the tables according to users＇ demands. This model is space economical. However, it faces two problems when applied to big data. First, join is an expensive operation, which prohibits a parallel database or a MapReduce-based system from achieving efficiency and scalability simultaneously. Second, join operations have to be executed repeatedly, while numerous join results can actually be reused by different queries. In this paper, we propose a new query processing frame- work for data warehouses. It pushes the join operations par- tially to the pre-processing phase and partially to the post- processing phase, so that data warehouse queries can be transformed into massive parallelized filter-aggregation oper- ations on the fact table. In contrast to the conventional query processing models, our approach is efficient, scalable and sta- ble despite of the large number of tables involved in the join. It is especially suitable for a large-scale parallel data ware- house. Our empirical evaluation on Hadoop shows that our framework exhibits linear scalability and outperforms some existing approaches by an order of magnitude.展开更多
文摘Heavy tamping is one of the important methods for ground treatment. But the vibration is often a problem that restricts the application during heavy tamping. On the other hand, as an instant impact load with controllable energy, heavy tamping is a good test in situ for the study of soil dynamics. With the analysis in the field of frequency, deductive method for medium effecting function and excitation function of heavy tamping is put forward in this paper.
文摘The fundamental solution to dynamic elastic differential equation after the Laplace transformation, which was obtained by Cruse and Rizzo, has been utilized to solve the boundary integral equation formulated by the weighted residual method. The boundary element method has been applied to dealing with the heavy tamping problem. As the elasticity modulus of soil is gradually increased after each tamping, and the loading modulus and unloading modulus are quite different, residual deformations can be finally obtained for each tamping. This is a method of nonlinear elastic analysis. The relationship of hammer velocity and falling distance for heavy tamping within liquid has been derived, so providing a theoretical background for heavy tamping under water.
基金Project(2017QNA21)supported by the Fundamental Research Funds for the Central Universities of ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘Backfill hydraulic support is the key equipment in achieving coal mining and solid backfilling simultaneously in solid backfill mining technology.Based on the summary and analysis of main types,basic structural properties and filed application of backfill hydraulic support,this work has firstly proposed the basic principle of backfill hydraulic support optimization design and provided the method of optimal design of key structural components,like four-bar linkage,rear canopy and tamping structure;the method is further elaborated as changing hinging position of upper bar to optimize four-bar linkage,by lengthening or shortening the rear canopy to optimize length ratio of canopy;and by changing length and hinging position of tamping structure as well as suspension height of backfill scrape conveyor to realize optimization of tamping structure.On this basis,the process of optimal design of backfill hydraulic support is built.The optimal design case of ZC5200/14.5/30 six columns-four bar linkage used in 7203 W workface of Zhaizhen Coal Mine shows that the backfill properties like horizontal roof gap,vertical horizontal gap,tamping angle and tamping head gap are improved obviously through optimizing four-bar linkage,canopy length and tamping structure according to the optimal design method proposed in this work.
文摘It is difficult to distinguish tamping coke and top charging coke by conventional testing methods, such as cold strength, abrasion resistance, reactivity and strength after reaction. Some of tamping coket s properties were even bet-ter than those of top charging coke, hut from practical using effects of blast furnace, tamping coke was not as good as top charging coke. The reaction conditions were featured as high temperature, high alkali condition, intense reac-tion atmosphere and short time. Distribution of porosity in profile, microstructure and slag forming property of ash were analyzed and following conclusions were obtained. After alkali-rich reaction, there were obvious differences be- tween top charging coke and tamping coke in microstructure, The porosityts unevenness of tamping coke was greater than those of top charging coke, and tamping coke was with less and big pores in out space and inner part was dense with more throughout pores. After phase diagram and microstructure analysis, it could he obtained that ash forming characteristics of top charging coke were better than those of tamping coke, and top charging coke＇ s pores were blocked more seriously than those of tamping coke. From analysis of tuyere samples, it could be found that calcium content of ash in coke＇s pores was small and it should belong to coke＇s inherent ash; kalium （wκ =28%） was unusu-ally high in coke. so the situation of high alkali was close to real blast furnace reaction condition.
基金supported financially by the European Space Agency (No. 4000112844/14/NL/FE)European Space Agency (No. 4000112844/14/NL/FE)+1 种基金the Irish Research Council (No. GOIPD2017-912)the Marie Curie Actions project number 333663 (FP7-People-2012-CIG)
文摘This work details new insights into the in-process densification mechanism of cold spray Al coatings. The results show a trend counter to common observations: coating plastic deformation levels and coating density decreases with an increase in particle impact velocity. A lower particle impact velocity and the consequent lower deposition efficiency(DE) results in greater tamping energy per unit volume of deposit,which is the primary reason for the observed trend. This is the first time that DE has been shown to have a non-linear impact on the density of a cold spray coating, with particle in-process tamping being the primary mechanism for coating densification.
文摘The rapidly increasing scale of data warehouses is challenging today＇s data analytical technologies. A con- ventional data analytical platform processes data warehouse queries using a star schema -- it normalizes the data into a fact table and a number of dimension tables, and during query processing it selectively joins the tables according to users＇ demands. This model is space economical. However, it faces two problems when applied to big data. First, join is an expensive operation, which prohibits a parallel database or a MapReduce-based system from achieving efficiency and scalability simultaneously. Second, join operations have to be executed repeatedly, while numerous join results can actually be reused by different queries. In this paper, we propose a new query processing frame- work for data warehouses. It pushes the join operations par- tially to the pre-processing phase and partially to the post- processing phase, so that data warehouse queries can be transformed into massive parallelized filter-aggregation oper- ations on the fact table. In contrast to the conventional query processing models, our approach is efficient, scalable and sta- ble despite of the large number of tables involved in the join. It is especially suitable for a large-scale parallel data ware- house. Our empirical evaluation on Hadoop shows that our framework exhibits linear scalability and outperforms some existing approaches by an order of magnitude.
