Here,we consider earlier Upper Paleolithic sites in the Selenga River Basin,the main fluvial input of Lake Baikal that flows through northern Mongolia and the southwestern Transbaikal region of Russia.Lithic industrie...Here,we consider earlier Upper Paleolithic sites in the Selenga River Basin,the main fluvial input of Lake Baikal that flows through northern Mongolia and the southwestern Transbaikal region of Russia.Lithic industries from these sites can be attributed to the laminar Initial Upper Paleolithic(IUP)technocomplex,widespread in southern Siberia and Central Asia.IUP industries appear in the Selenga Basin about 45 kaBP cal.Aspects of regional typological variability and the transport of exotic raw materials over long distances indicate that these populations participated in developed exchange networks and employed high mobility targeting the acquisition of necessary raw materials.Two site types are present:quarry-workshops in northern Mongolia and generalized activity settlements in the southwestern Transbaikal.Although faunal data are limited,we interpret available information as indicating a specialization on hunting,focusing on migrating steppe game species.The distribution of sites in the mid-altitudes and landscapes of the Selenga-Orkhon geographical region and the geomorphological homogeneity of this territory also supported interregional human moves during the IUP.展开更多
[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and ha...[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and hatched under laboratory condition. The indexes such as body weight, body length, length in front of anus and body height were measured to establish larvae growth model. [Result] When the water temperature was （20±1.5） ℃, the body length and body weight of newly hatched larvae were （10.28±0.05） mm and （7.79±0.08） mg, respectively. O. sima larvae begin to feed on the 4 th day after hatching, the initial feeding rate was 48%, the highest feeding rate was 100% on the 6 th d. The-point-of-no-return （PNR） was 13.5 d. In addition, it was also observed that the appearance time of PNR point of O. sima larvae was close to death time of completely starved group, being only 2 d, indicating that once O. sima larvae reached the PNR point, they would face death threats within short time. Therefore, various growth conditions for O. sima larvae should be satisfied to ensure full development of all organs, thereby reducing death and growth stagnation caused by adverse environment in early postembryonic stage. [Conclusion] The study provided theoretical basis for solving the problems in artificial breeding.展开更多
After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the stre...After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.展开更多
As the startup phase of HL-2A operation and the first divertor tokamak device in China, it is important to identify the species of impurity, estimate the concentration of impurities and compare the different behaviors...As the startup phase of HL-2A operation and the first divertor tokamak device in China, it is important to identify the species of impurity, estimate the concentration of impurities and compare the different behaviors of radiation in limiter and divertor configurationt. In startup phase of HL-2A, glowing discharge cleaning （GDC） is used as a conventional wall conditioning technology and titanium gettering is used occasionally in closed divertor chamber during SN configuration discharges phase.展开更多
文摘Here,we consider earlier Upper Paleolithic sites in the Selenga River Basin,the main fluvial input of Lake Baikal that flows through northern Mongolia and the southwestern Transbaikal region of Russia.Lithic industries from these sites can be attributed to the laminar Initial Upper Paleolithic(IUP)technocomplex,widespread in southern Siberia and Central Asia.IUP industries appear in the Selenga Basin about 45 kaBP cal.Aspects of regional typological variability and the transport of exotic raw materials over long distances indicate that these populations participated in developed exchange networks and employed high mobility targeting the acquisition of necessary raw materials.Two site types are present:quarry-workshops in northern Mongolia and generalized activity settlements in the southwestern Transbaikal.Although faunal data are limited,we interpret available information as indicating a specialization on hunting,focusing on migrating steppe game species.The distribution of sites in the mid-altitudes and landscapes of the Selenga-Orkhon geographical region and the geomorphological homogeneity of this territory also supported interregional human moves during the IUP.
基金Supported by Special Funds for Breeding Research of Sichuan Provincial Department of Finance(2006YZGG08-002)~~
文摘[Objective] The paper was to study the growth and development of Onychostoma sima in postembryonic development stage. [Method] The oosperm was obtained by artificial spawning and artificial insemination method, and hatched under laboratory condition. The indexes such as body weight, body length, length in front of anus and body height were measured to establish larvae growth model. [Result] When the water temperature was （20±1.5） ℃, the body length and body weight of newly hatched larvae were （10.28±0.05） mm and （7.79±0.08） mg, respectively. O. sima larvae begin to feed on the 4 th day after hatching, the initial feeding rate was 48%, the highest feeding rate was 100% on the 6 th d. The-point-of-no-return （PNR） was 13.5 d. In addition, it was also observed that the appearance time of PNR point of O. sima larvae was close to death time of completely starved group, being only 2 d, indicating that once O. sima larvae reached the PNR point, they would face death threats within short time. Therefore, various growth conditions for O. sima larvae should be satisfied to ensure full development of all organs, thereby reducing death and growth stagnation caused by adverse environment in early postembryonic stage. [Conclusion] The study provided theoretical basis for solving the problems in artificial breeding.
文摘After grouting the ducts in a large band beam and one-way slab post-tensioned floor system in a large shopping mall （in excess of 1.5 km2 in plan）, doubts arose concerning the level of initial prestress and the strength and serviceability of the slabs was questioned. To assess the strength of the slabs, it was assumed, as a worst case scenario, that some spans may have been constructed with zero initial prestress. Load tests on prototype specimens, with similar dimensions and reinforcement quantities as the floor slabs, were performed to assess the stress development in initially unstressed, but fully grouted, tendons. Unexpected bond failures occurred at the junctions of slab and band beam where the abrupt change in section depth caused a sudden change in tendon stress. The maximum stress that was developed in the initially unstressed tendons at these locations was about 60% of the strength of the tendons.
文摘As the startup phase of HL-2A operation and the first divertor tokamak device in China, it is important to identify the species of impurity, estimate the concentration of impurities and compare the different behaviors of radiation in limiter and divertor configurationt. In startup phase of HL-2A, glowing discharge cleaning （GDC） is used as a conventional wall conditioning technology and titanium gettering is used occasionally in closed divertor chamber during SN configuration discharges phase.
