Three ponds with the areas of 800, 1 000 and 1 000 m2 were settled in Yambajan aquaculture base for rearing test of Ictalurus punctatus in plateau zone. The results showed that as 30 000 fries were released, 19 830 fi...Three ponds with the areas of 800, 1 000 and 1 000 m2 were settled in Yambajan aquaculture base for rearing test of Ictalurus punctatus in plateau zone. The results showed that as 30 000 fries were released, 19 830 fingerlings of 1. punctatus were obtained after 270 d rearing, with the average body length of 21.2 cm, the average body weight of 216.5 g, the survival rate of 66.1%, and the fingerling harvest of 4 293.2 kg. Thus, it is effective and feasible to rear I. punctatus with residual heat resources of power plants in cold plateau zone.展开更多
In this paper, the suitability and construction technology of self-insulation walls were studied under the specific climatic conditions and regional resources of Hanzhong and Ankang in the hot summer and cold winter z...In this paper, the suitability and construction technology of self-insulation walls were studied under the specific climatic conditions and regional resources of Hanzhong and Ankang in the hot summer and cold winter zone of Southern Shaanxi. Through the calculation of heat transfer coefficient and thermal inertia index, combined with the specifications of the shale hollow brick and aerated concrete block of Hanzhong and Ankang in southern Shaanxi, the thermal performance and suitable thickness of the external wall using self-insulation materials that meet the Design Standard for Energy Efficiency of Residential Buildings(DBJ61-65-2011) in Shaanxi Province were obtained. The results showed that the self-insulation wall had technical suitability in the hot summer and cold winter zone. The research results provide not only a theoretical basis for the external wall insulation design of urban residential buildings in the hot summer and cold winter zone of southern Shaanxi, but also a reference for designers to carry out energy-saving design of external walls of residential buildings in other similar climate zones.展开更多
The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation o...The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation of the exterior?wall is a more feasible design to satisfy the energy efficiency of buildings in the?zone. However, the systematic research is urgently needed for the self-insulation of the exterior wall in the hot summer and cold winter zone of China. The paper tested the thermal performance of the common non-clay materials such as shale sintered hollow brick, sand autoclaved aerated concrete block, etc. by means of indoor experiments. The energy efficiency effect of the common materials was verified using dynamic calculation soft PKPM and several constitutions of exterior wall with different main bricks and insulation materials on the heat bridge were simulated, too. Besides, the tests of the thermal performance of exterior wall in real constructions were carried out to testify the practical effect of the recommended constitutions of exterior wall with different main bricks and insulation materials on the heat bridge. The conclusions are: the physical and thermal properties of the six non-clay wall material are better than the clay porous brick;the thermal performance of the non-clay brick can be improved obviously through the rational arrangement of the holes;shale sintered hollow brick after increasing the holes and rationalizing the hole arrangement and sand autoclaved aerated concrete block are recommended for buildings in the hot summer and cold winter area of China. The dynamic calculation results show that the thermal performances?of the non-clay materials are all satisfied with the energy efficiency;The heat transfer coefficient of the exterior wall with composition?③,?in which?the main wall was sand autoclaved aerated concrete block and the material on the heat bridge was sand autoclaved aerated concrete plate, is the smallest among the three recommended compositions.展开更多
To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting materia...To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting material)at 20 and 3℃.The results show that low temperature only delays the strength development of FSAC grouting material within the first 3 d.Then,the effect of four typical early strength synergists on the early properties of FSAC grouting material was evaluated to optimize the early(£1 d)strength at 3℃.The most effective synergist,Ca(HCOO)_(2),which enhances the low-temperature early strength without compromising fluidity was selected based on strength and fluidity tests.Its micro-mechanism was analyzed by XRD,TG,and SEM methods.The results reveal that the most suitable dosage range is 0.3 wt%−0.5 wt%.Proper addition of Ca(HCOO)_(2)changed the crystal morphology of the hydration products,decreased the pore size and formed more compact hydration products by interlocking and overlapping.However,excessive addition of Ca(HCOO)_(2)inhibited the hydration reaction,resulting in a simple and loose structure of the hydration products.The research results have reference value for controlling surrounding rock deformation and preventing water and mud inrushes during the excavation in cold region tunnels.展开更多
为研究激活作用下乳化沥青冷再生混合料强度的增强机理,首先研究激活作用下乳化沥青冷再生混合料路用性能的演变,继而通过扫描电子显微镜(scanning electron microscopy,SEM)、能量色散谱仪(energy dispersive spectroscopy,EDS)和原子...为研究激活作用下乳化沥青冷再生混合料强度的增强机理,首先研究激活作用下乳化沥青冷再生混合料路用性能的演变,继而通过扫描电子显微镜(scanning electron microscopy,SEM)、能量色散谱仪(energy dispersive spectroscopy,EDS)和原子力显微镜(atomic force microscopy,AFM)研究激活作用下界面过渡区(interfacial transition zone,ITZ)的形貌变化,分析混合料强度与界面过渡区形貌间的关系。结果表明:在乳化沥青冷再生混合料中加入激活剂能够有效提高其高温性能、低温性能和水稳定性能,激活乳化沥青冷再生混合料的15℃劈裂强度较不掺加激活剂的乳化沥青冷再生混合料提高达30.8%;激活乳化沥青冷再生混合料的界面结构紧密,随着养生时间的增加,界面过渡区宽度逐渐减小。激活作用下养生7 d的界面过渡区宽度与未激活状态下相比减小了77.8%。激活作用下旧沥青中的轻质组分可以得到有效补充,同时,激活剂中的苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrence-butadiene-styrence,SBS)可以扩散到旧沥青中进行改性,从而促进了新旧沥青的融合。展开更多
By using the monthly mean grid data of NCAR/NCEP reanalysis at 500 hPa geopotential height from 1958 to 1997,the relationship between the Northeast cold vortex and the western Pacific subtropical high was analyzed.The...By using the monthly mean grid data of NCAR/NCEP reanalysis at 500 hPa geopotential height from 1958 to 1997,the relationship between the Northeast cold vortex and the western Pacific subtropical high was analyzed.The influence of the sea surface temperature(SST) and outgoing longwave radiation(OLR) on the Northeast cold vortex and subtropical high was studied.As was shown in the results,in summer,there was a positive correlation between the Northeast cold vortex and the subtropical high,and an anti-phase relationship existed between the threshold characteristic line of GMS-SST=28 ℃ and the height index of the Northeast cold vortex and the subtropical high.With the gradual northward moving of the threshold characteristic line,the subtropical high was weakening,and the Northeast cold vortex was increasing and strengthening.展开更多
Cracking morphology in the fusion zone of HQ130 high strength steel was researched by 'the y-slit test' and 'three-point bend test', ultrasonic test and microscope. HQ130 and QJ63 high strength steel w...Cracking morphology in the fusion zone of HQ130 high strength steel was researched by 'the y-slit test' and 'three-point bend test', ultrasonic test and microscope. HQ130 and QJ63 high strength steel was welded by Ar+CO2 gas shielded arc welding under the condition without preheating. Experimental results indicated that welding cracks were produced in the partially melted zone of the weld root of HQ130 steel side and propagated parallel to the fusion zone. The cracks were developed alternatively between the weld and the partially melted zone, and are not strictly ruptured at W/F (weld metal/fusion zone) boundary surface. Controlling weld heat input (E) about 16 kJ/cm could make the cracking rate lowest and satisfy the performance requirement of welded joint zone.展开更多
As a result of research into the cold rolling theory and practice, a complex of mathematical models and model-based process solutions has been elaborated to improve quality of cold rolled steel strips and reduce energ...As a result of research into the cold rolling theory and practice, a complex of mathematical models and model-based process solutions has been elaborated to improve quality of cold rolled steel strips and reduce energy consumption. The use of the above designs made it possible to establish a number of new regularities and employ them for cold rolling practice improvement and cold-rolled strip quality upgrading.展开更多
文摘Three ponds with the areas of 800, 1 000 and 1 000 m2 were settled in Yambajan aquaculture base for rearing test of Ictalurus punctatus in plateau zone. The results showed that as 30 000 fries were released, 19 830 fingerlings of 1. punctatus were obtained after 270 d rearing, with the average body length of 21.2 cm, the average body weight of 216.5 g, the survival rate of 66.1%, and the fingerling harvest of 4 293.2 kg. Thus, it is effective and feasible to rear I. punctatus with residual heat resources of power plants in cold plateau zone.
文摘In this paper, the suitability and construction technology of self-insulation walls were studied under the specific climatic conditions and regional resources of Hanzhong and Ankang in the hot summer and cold winter zone of Southern Shaanxi. Through the calculation of heat transfer coefficient and thermal inertia index, combined with the specifications of the shale hollow brick and aerated concrete block of Hanzhong and Ankang in southern Shaanxi, the thermal performance and suitable thickness of the external wall using self-insulation materials that meet the Design Standard for Energy Efficiency of Residential Buildings(DBJ61-65-2011) in Shaanxi Province were obtained. The results showed that the self-insulation wall had technical suitability in the hot summer and cold winter zone. The research results provide not only a theoretical basis for the external wall insulation design of urban residential buildings in the hot summer and cold winter zone of southern Shaanxi, but also a reference for designers to carry out energy-saving design of external walls of residential buildings in other similar climate zones.
文摘The energy efficiency design of the exterior wall in the buildings of the hot summer and cold winter zone of China should consider the heat prevention in summer and the heat insulation in winter. The self-insulation of the exterior?wall is a more feasible design to satisfy the energy efficiency of buildings in the?zone. However, the systematic research is urgently needed for the self-insulation of the exterior wall in the hot summer and cold winter zone of China. The paper tested the thermal performance of the common non-clay materials such as shale sintered hollow brick, sand autoclaved aerated concrete block, etc. by means of indoor experiments. The energy efficiency effect of the common materials was verified using dynamic calculation soft PKPM and several constitutions of exterior wall with different main bricks and insulation materials on the heat bridge were simulated, too. Besides, the tests of the thermal performance of exterior wall in real constructions were carried out to testify the practical effect of the recommended constitutions of exterior wall with different main bricks and insulation materials on the heat bridge. The conclusions are: the physical and thermal properties of the six non-clay wall material are better than the clay porous brick;the thermal performance of the non-clay brick can be improved obviously through the rational arrangement of the holes;shale sintered hollow brick after increasing the holes and rationalizing the hole arrangement and sand autoclaved aerated concrete block are recommended for buildings in the hot summer and cold winter area of China. The dynamic calculation results show that the thermal performances?of the non-clay materials are all satisfied with the energy efficiency;The heat transfer coefficient of the exterior wall with composition?③,?in which?the main wall was sand autoclaved aerated concrete block and the material on the heat bridge was sand autoclaved aerated concrete plate, is the smallest among the three recommended compositions.
基金Projcet(52279119)supported by the National Natural Science Foundation of ChinaProject(XZ202201ZY0021G)supported by the Science and Technology Planning Project of Xizang Autonomous Region,China+1 种基金Project(2019QZKK0904)supported by the Second Xizang Plateau Scientific Expedition and Research Program of ChinaProject(51922104)supported by the National Natural Science Foundation for Distinguished Young Scholars of China。
文摘To develop suitable grouting materials for water conveyance tunnels in cold regions,firstly,this study investigated the performance evolution of ferrite-rich sulfoaluminate-based composite cement(FSAC grouting material)at 20 and 3℃.The results show that low temperature only delays the strength development of FSAC grouting material within the first 3 d.Then,the effect of four typical early strength synergists on the early properties of FSAC grouting material was evaluated to optimize the early(£1 d)strength at 3℃.The most effective synergist,Ca(HCOO)_(2),which enhances the low-temperature early strength without compromising fluidity was selected based on strength and fluidity tests.Its micro-mechanism was analyzed by XRD,TG,and SEM methods.The results reveal that the most suitable dosage range is 0.3 wt%−0.5 wt%.Proper addition of Ca(HCOO)_(2)changed the crystal morphology of the hydration products,decreased the pore size and formed more compact hydration products by interlocking and overlapping.However,excessive addition of Ca(HCOO)_(2)inhibited the hydration reaction,resulting in a simple and loose structure of the hydration products.The research results have reference value for controlling surrounding rock deformation and preventing water and mud inrushes during the excavation in cold region tunnels.
文摘为研究激活作用下乳化沥青冷再生混合料强度的增强机理,首先研究激活作用下乳化沥青冷再生混合料路用性能的演变,继而通过扫描电子显微镜(scanning electron microscopy,SEM)、能量色散谱仪(energy dispersive spectroscopy,EDS)和原子力显微镜(atomic force microscopy,AFM)研究激活作用下界面过渡区(interfacial transition zone,ITZ)的形貌变化,分析混合料强度与界面过渡区形貌间的关系。结果表明:在乳化沥青冷再生混合料中加入激活剂能够有效提高其高温性能、低温性能和水稳定性能,激活乳化沥青冷再生混合料的15℃劈裂强度较不掺加激活剂的乳化沥青冷再生混合料提高达30.8%;激活乳化沥青冷再生混合料的界面结构紧密,随着养生时间的增加,界面过渡区宽度逐渐减小。激活作用下养生7 d的界面过渡区宽度与未激活状态下相比减小了77.8%。激活作用下旧沥青中的轻质组分可以得到有效补充,同时,激活剂中的苯乙烯-丁二烯-苯乙烯嵌段共聚物(styrence-butadiene-styrence,SBS)可以扩散到旧沥青中进行改性,从而促进了新旧沥青的融合。
文摘By using the monthly mean grid data of NCAR/NCEP reanalysis at 500 hPa geopotential height from 1958 to 1997,the relationship between the Northeast cold vortex and the western Pacific subtropical high was analyzed.The influence of the sea surface temperature(SST) and outgoing longwave radiation(OLR) on the Northeast cold vortex and subtropical high was studied.As was shown in the results,in summer,there was a positive correlation between the Northeast cold vortex and the subtropical high,and an anti-phase relationship existed between the threshold characteristic line of GMS-SST=28 ℃ and the height index of the Northeast cold vortex and the subtropical high.With the gradual northward moving of the threshold characteristic line,the subtropical high was weakening,and the Northeast cold vortex was increasing and strengthening.
文摘Cracking morphology in the fusion zone of HQ130 high strength steel was researched by 'the y-slit test' and 'three-point bend test', ultrasonic test and microscope. HQ130 and QJ63 high strength steel was welded by Ar+CO2 gas shielded arc welding under the condition without preheating. Experimental results indicated that welding cracks were produced in the partially melted zone of the weld root of HQ130 steel side and propagated parallel to the fusion zone. The cracks were developed alternatively between the weld and the partially melted zone, and are not strictly ruptured at W/F (weld metal/fusion zone) boundary surface. Controlling weld heat input (E) about 16 kJ/cm could make the cracking rate lowest and satisfy the performance requirement of welded joint zone.
文摘As a result of research into the cold rolling theory and practice, a complex of mathematical models and model-based process solutions has been elaborated to improve quality of cold rolled steel strips and reduce energy consumption. The use of the above designs made it possible to establish a number of new regularities and employ them for cold rolling practice improvement and cold-rolled strip quality upgrading.
