Human normal endometrium was examined in ultrathin sections. Nucleolar channel system (NCS) appeared in the endometrial epithelial cells during the early and mid secretory phase of menstrual cycle. The NCS was a hollo...Human normal endometrium was examined in ultrathin sections. Nucleolar channel system (NCS) appeared in the endometrial epithelial cells during the early and mid secretory phase of menstrual cycle. The NCS was a hollow ball like structure of different sizes and was composed of 2 to 5 rows of tubules embedded in an amorphous matrix. On its surface there were numerous electron dense particles resembling ribosonies. It was usually located within or associated with the nucleolus. Sometimes, it was close to the nuclear envelope or protruding out from the nucleus. On occasion, NCS with simplified structure was found in the perinuclear cytoplasm. Concepts concerning the genesis, involution and function(s) of the NCS were discussed.展开更多
The influence of enlarged section parameters on pressure transients of high-speed train passing through a tunnel was investigated by numerical simulation.The calculation results obtained by the structured and unstruct...The influence of enlarged section parameters on pressure transients of high-speed train passing through a tunnel was investigated by numerical simulation.The calculation results obtained by the structured and unstructured grid and the experimental results of smooth wall tunnel were verified.Numerical simulation studies were conducted on three tunnel enlarged section parameters,the enlarged section distribution along circumferential direction,the enlarged section area and the enlarged section distribution along tunnel length direction.The calculation results show that the influence of the different enlarged section distributions along tunnel circumferential direction on pressure transients in the tunnel is basically consistent.There is an optimal enlarged section area for the minimum value of the pressure variation amplitude and the average pressure variation in the tunnel.The law of the pressure variation amplitude and the average pressure variation of the enlarged section distribution along tunnel length direction are obtained.展开更多
In order to establish an effective wireless communication system in an underground coal-mine environment, the propagation of radio waves through a rectangular-like mine tunnel was investigated by jointly, considering ...In order to establish an effective wireless communication system in an underground coal-mine environment, the propagation of radio waves through a rectangular-like mine tunnel was investigated by jointly, considering both the dielectric constant and the reflectance of a mine tunnel. By combining free space and modified waveguide propagation models, we propose a new hybrid propagation model based on ray tracing. Simulation results have shown the effectiveness of establishing a wireless Local Area Network (LAN) in this coal-mine environment. The results of this research will be very useful as a guide in the design and development of tunnel wireless LAN systems.展开更多
文摘Human normal endometrium was examined in ultrathin sections. Nucleolar channel system (NCS) appeared in the endometrial epithelial cells during the early and mid secretory phase of menstrual cycle. The NCS was a hollow ball like structure of different sizes and was composed of 2 to 5 rows of tubules embedded in an amorphous matrix. On its surface there were numerous electron dense particles resembling ribosonies. It was usually located within or associated with the nucleolus. Sometimes, it was close to the nuclear envelope or protruding out from the nucleus. On occasion, NCS with simplified structure was found in the perinuclear cytoplasm. Concepts concerning the genesis, involution and function(s) of the NCS were discussed.
基金Project (2016YFB1200602-11) supported by National Key R&D Plan of China
文摘The influence of enlarged section parameters on pressure transients of high-speed train passing through a tunnel was investigated by numerical simulation.The calculation results obtained by the structured and unstructured grid and the experimental results of smooth wall tunnel were verified.Numerical simulation studies were conducted on three tunnel enlarged section parameters,the enlarged section distribution along circumferential direction,the enlarged section area and the enlarged section distribution along tunnel length direction.The calculation results show that the influence of the different enlarged section distributions along tunnel circumferential direction on pressure transients in the tunnel is basically consistent.There is an optimal enlarged section area for the minimum value of the pressure variation amplitude and the average pressure variation in the tunnel.The law of the pressure variation amplitude and the average pressure variation of the enlarged section distribution along tunnel length direction are obtained.
基金supported by the National Natural Science Foundation of China (No.10974044)the Open Project of the Key Lab of the Technique of Electricity Transmission, Distribution and Conservation in Changzhou, China
文摘In order to establish an effective wireless communication system in an underground coal-mine environment, the propagation of radio waves through a rectangular-like mine tunnel was investigated by jointly, considering both the dielectric constant and the reflectance of a mine tunnel. By combining free space and modified waveguide propagation models, we propose a new hybrid propagation model based on ray tracing. Simulation results have shown the effectiveness of establishing a wireless Local Area Network (LAN) in this coal-mine environment. The results of this research will be very useful as a guide in the design and development of tunnel wireless LAN systems.
