Rectangular section control technology （RSCT） was introduced to achieve high-precision profile control during silicon steel rolling. The RSCT principle and method were designed, and the whole RSCT control strategy w...Rectangular section control technology （RSCT） was introduced to achieve high-precision profile control during silicon steel rolling. The RSCT principle and method were designed, and the whole RSCT control strategy was developed. Specifically, RSCT included roll contour design, roiling technology optimization, and control strategy development, aiming at both hot strip mills （HSMs） and cold strip mills （CSMs）. Firstly, through the high-performance variable crown （HVC） work roll optimization design in the upper-stream stands and the limited shifting technology for schedule-free rolling in the downstream stands of HSMs, a hot strip with a stable crown and limited wedge, ：local spot, and single wave was obtained, which was suitable for cold rolling. Secondly, an approximately rectangular section was obtained by edge varying contact （EVC） work roll contour design, edge-drop setting control, and. closed loop control in the upper-stream, stands of CSMs. Moreover, complex-mode flatness control was realized by coordinating multiple shape-control methods in the downstream stands of CSMs. In addition, the RSCT approach was applied in several silicon-steel production plants, where an outsicanding performance and remarkable economic benefits were observed.展开更多
Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan r...Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology.展开更多
Through analysis on the background to develop eco-tourism and necessity for ecological compensation,based on specific condition of Hukou County,in line with the situation to develop eco-tourism during ecological water...Through analysis on the background to develop eco-tourism and necessity for ecological compensation,based on specific condition of Hukou County,in line with the situation to develop eco-tourism during ecological water control project of Poyang Lake,residents' interest protection system and ecological benefit safeguard system for eco-tourism compensation were put forward.展开更多
A new hypersonic inlet named three-dimensional section controllable internal waverider inlet is presented in this paper to achieve the goal of section shape geometric transition and complete capture of the upstream ma...A new hypersonic inlet named three-dimensional section controllable internal waverider inlet is presented in this paper to achieve the goal of section shape geometric transition and complete capture of the upstream mass. On the basis of the association between hypersonic waverider airframe and streamtraced hypersonic inlet, the waverider concept is extended to yield results for the internal flows, namely internal waverider concept. It is proven theoretically that not osculating cones but osculating axisymmetric theory is appropriate for the design of section controllable internal waverider inlet. And two design methods out of the internal waverider concept are proposed subsequently to construct two inlets with specific section shape request, triangle to ellipse and rectangle to ellipse ones. The calculation results show that the inlets are capable of keeping their shock structures and the main flow characteristics exactly as their derived flowfield. Further, the inlets successfully capture all the upstream mass despite their complicated cross-section transitions. It is believed that the concept proposed ex- plores a new way of designing three-dimensional hypersonic inlets with special demand of section shape transition. However, the detailed flow characteristic and the performance of the internal waverider inlets are still under investigation.展开更多
The effect of mandrel with the structure of ball and socket on the cross section quality of thin-walled tube numerical controlled(NC) bending was studied by numerical simulation method, combined with theoretical (anal...The effect of mandrel with the structure of ball and socket on the cross section quality of thin-walled tube numerical controlled(NC) bending was studied by numerical simulation method, combined with theoretical (analysis) and experiment. Influencing factors of the mandrel include the count of mandrel heads, the diameter of mandrel and its position. According to the principle of NC tube bending, quality defects possibly produced in thin-walled tube NC bending process were analyzed and two parameters were proposed in order to describe the cross section quality of thin-walled tube NC bending. According to the geometrical dimension of tube and dies, the range of mandrel protrusion was derived. The finite element model of thin-walled tube NC bending was established based on the DYNAFORM platform, and key technological problems were solved. The model was verified by experiment. The effect of the number of mandrel heads, the diameter of mandrel and the protrusion length of mandrel on the cross section quality of thin-walled tube NC bending was revealed and how to choose mandrel parameters was presented.展开更多
According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and devel...According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.展开更多
Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir ...Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10<sup>−</sup><sup>3</sup> µm<sup>2</sup>. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir.展开更多
基金Item Sponsored by National Natural Science Foundation of China(51304017)National Key Technology Research and Development Program of the 12th Five-year Plan of China(2012BAF04B02)Fundamental Research Funds for Central Universities of China(FRF-SD-12-013B)
文摘Rectangular section control technology （RSCT） was introduced to achieve high-precision profile control during silicon steel rolling. The RSCT principle and method were designed, and the whole RSCT control strategy was developed. Specifically, RSCT included roll contour design, roiling technology optimization, and control strategy development, aiming at both hot strip mills （HSMs） and cold strip mills （CSMs）. Firstly, through the high-performance variable crown （HVC） work roll optimization design in the upper-stream stands and the limited shifting technology for schedule-free rolling in the downstream stands of HSMs, a hot strip with a stable crown and limited wedge, ：local spot, and single wave was obtained, which was suitable for cold rolling. Secondly, an approximately rectangular section was obtained by edge varying contact （EVC） work roll contour design, edge-drop setting control, and. closed loop control in the upper-stream, stands of CSMs. Moreover, complex-mode flatness control was realized by coordinating multiple shape-control methods in the downstream stands of CSMs. In addition, the RSCT approach was applied in several silicon-steel production plants, where an outsicanding performance and remarkable economic benefits were observed.
文摘Taking state-controlled section of Xuzhou Peiyan river as an example,the current water quality was monitored,and the cause of over water quality standard was analyzed.The results showed that the pollutants of Peiyan river were mainly from the urban river segment,and the immediate cause of over standard was tributary pollutants in urban river segment with the runoff into rivers.So we should strengthen the maintenance of drainage control and gate-han,accelerate the construction of urban wastewater treatment facilities and supporting pipe network,promote rural decentralized sewage treatment,prevent and control livestock and poultry pollution,pesticides and fertilizers pollution,and intercept non-point source pollution by using eco-technology.
基金Supported by Key Bid Program of Poyang Lake Ecological Economy Research Center of Jiangxi Province(09KJ01)~~
文摘Through analysis on the background to develop eco-tourism and necessity for ecological compensation,based on specific condition of Hukou County,in line with the situation to develop eco-tourism during ecological water control project of Poyang Lake,residents' interest protection system and ecological benefit safeguard system for eco-tourism compensation were put forward.
基金Supported by the National Natural Science Foundation of China(Grant No.90405009)
文摘A new hypersonic inlet named three-dimensional section controllable internal waverider inlet is presented in this paper to achieve the goal of section shape geometric transition and complete capture of the upstream mass. On the basis of the association between hypersonic waverider airframe and streamtraced hypersonic inlet, the waverider concept is extended to yield results for the internal flows, namely internal waverider concept. It is proven theoretically that not osculating cones but osculating axisymmetric theory is appropriate for the design of section controllable internal waverider inlet. And two design methods out of the internal waverider concept are proposed subsequently to construct two inlets with specific section shape request, triangle to ellipse and rectangle to ellipse ones. The calculation results show that the inlets are capable of keeping their shock structures and the main flow characteristics exactly as their derived flowfield. Further, the inlets successfully capture all the upstream mass despite their complicated cross-section transitions. It is believed that the concept proposed ex- plores a new way of designing three-dimensional hypersonic inlets with special demand of section shape transition. However, the detailed flow characteristic and the performance of the internal waverider inlets are still under investigation.
文摘The effect of mandrel with the structure of ball and socket on the cross section quality of thin-walled tube numerical controlled(NC) bending was studied by numerical simulation method, combined with theoretical (analysis) and experiment. Influencing factors of the mandrel include the count of mandrel heads, the diameter of mandrel and its position. According to the principle of NC tube bending, quality defects possibly produced in thin-walled tube NC bending process were analyzed and two parameters were proposed in order to describe the cross section quality of thin-walled tube NC bending. According to the geometrical dimension of tube and dies, the range of mandrel protrusion was derived. The finite element model of thin-walled tube NC bending was established based on the DYNAFORM platform, and key technological problems were solved. The model was verified by experiment. The effect of the number of mandrel heads, the diameter of mandrel and the protrusion length of mandrel on the cross section quality of thin-walled tube NC bending was revealed and how to choose mandrel parameters was presented.
文摘According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.
文摘Based on the sheet, scanning electron microscope and high pressure mercury analysis method, this paper takes Jiyuan oilfield-Ma Jia mountain district 4 5 sandstone reservoir as the research object, from the reservoir petrology, pore type and porosity, permeability, the system analyzed the reservoir characteristics and its control factors. The results show that the sandstone in the 4 5 section of Baoziwan-Majiashan area of Jiyuan oilfield is fine in size and high in filling content. The pore types were dominated by intergranular pores and dissolved pores, with a low face rate. The reservoir property is relatively poor, with mean porosity of 11.11% and mean permeability of 1.16 × 10<sup>−</sup><sup>3</sup> µm<sup>2</sup>. In the low porous, low otonic background, the development of relatively high pore hypertonic areas. Compaction and cementation should play a destructive role in reservoir properties, and dissolution should play a positive role in reservoir properties. Compaction adjusts the migration of clay minerals and miscellaneous bases in the original sediment in the study area, greatly reducing the porosity and permeability of the reservoir;the development of the cement cement, carbonate cementation and some quartz secondary compounds reduces the storage space;the dissolution effect, especially the secondary dissolution pores of the reservoir, which obviously improves the properties of the reservoir.
