分类： 地球科学 >> 地质学 提交时间： 2017-07-31 合作期刊: 《古脊椎动物学报》
摘要： A new fossil specimen from the early Middle Eocene of an Irdin Manha Formation equivalent (Erden Obo Section) in Nei Mongol (Inner Mongolia), China appears to be derived from an ameghinornithid-like species, and may represent the frst record of the Ameghinornithidae in Asia. This new specimen exhibits the subcircular lateral condyle outline, the absence of an ossified supratendinal bridge, an enlarged flattened tubercle lateral to the extensor sulcus, and other features shared among known ameghinornithid and ameghinornithid-like birds. The Nei Mongol fossil is roughly contemporaneous with the oldest records of the ameghinornithids from Europe (~48 Ma). The absence of this group of birds from North America, and their occurrence in Europe and Asia during the Eocene contrasts with the contemporaneous Nei Mongol mammalian fauna that is comprised largely of Asian taxa with a few distinct linkages to North America. Along with the record of an ameghinornithid-like bird from the early Oligocene deposits of the Fayum area in Egypt, it seems that this extinct bird group had a much larger geographic distribution than previously recognized.
分类： 地球科学 >> 海洋科学 提交时间： 2017-07-17
摘要： In order to deal with the quality of Antarctic krill during the storage and transportation process caused by the failure of the supply system and the freezing equipment in the process of storage and circulation in the form of frozen products, the project team changed the refrigerated environment to the Antarctic The effect of krill quality was studied. When the ambient temperature increased from -20 ℃ to -12 ℃, -7 ℃, -3 ℃, -1.5 ℃, 0 ℃, 1 ℃, 2.5 ℃, 4 ℃, 6 ℃ , 8 ℃, 12.5 ℃, 16 ℃, the Antarctic krill samples for sensory evaluation, pH value, the meat rate and soup turbidity and other quality indicators of the determination. The results show that when the ambient temperature from -20 ℃ up to -1.5 ℃ process, the Antarctic krill soup after cooking is more clear, little change in turbidity, pH quickly increased from 7.60 to 7.85 Antarctic krill muscle elasticity began to change Poor, the sensory quality has begun to change from good to change; when the temperature from -1.5 ℃ to 4 ℃, the pH value slowly increased, there is a certain fluctuation, may be due to differences in the composition of the various components of the decision, Antarctic krill soup after the soup turbidity quickly increased from 0.5 to 0.7Brix maximum, sensory quality is still at a moderate level; when the temperature rose to 16 ℃, the pH has risen to 8.05, Antarctic krill Sensory quality from the change into a bad, this time the Antarctic krill has been unable to eat, only as a feed or other use.
分类： 地球科学 >> 海洋科学 提交时间： 2017-07-17
摘要： From August 25 to 29, 2014, the project team carried out the experiment of Antarctic krill trawl in the Beihai Bay of the South China Sea. In order to understand the flow field of the network model in the course of the experiment, it is necessary to record the speed of the ship and to grasp the flow field of the ocean. Therefore, the ocean velocity is measured during the experiment. The flow rate in this experiment was measured using an acoustic Doppler flowmeter (Vectrino Plus, Nortek, Norway). In order to compensate for the flow rate error caused by ship drift, the drift condition of the ship was also measured by the positioning device (Snapdragon MSM8274AB, Qualcomm, USA) used in the flow rate measurement. The results show that the actual velocity of the target sea area is in the range of 0.06-0.49 m / s and the direction is 216.17-351.70. And compared with the previous research, the influencing factors were analyzed. This study proves that it is feasible to use point Doppler flowmeter for velocity study in trawl model experiment.
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