A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region f...A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.展开更多
The proxy of U37 index is widely applied to K ’ reconstructing paleotemperature in the marine environment. However, the long-chain alkenones (LCAs) research is rarely reported in the liminic system. In this paper, we...The proxy of U37 index is widely applied to K ’ reconstructing paleotemperature in the marine environment. However, the long-chain alkenones (LCAs) research is rarely reported in the liminic system. In this paper, we studied LCAs in the surface sediments (0 —10 cm) of nine sulfate lakes in the Inner Mongolia Autonomous Region, Xinjiang Uygur Autonomous Region and Qinghai Province, China. LCAs are detected in eight of the nine lakes, except a dry salt lake —Lake Lop. The result shows that LCAs might be uni- versal in the sulfate lakes. In most of the surface samples, the sequence of the abundance of the long-chain alkenones is C37>C38>C39>C40. And C37︰4 methyl ketone is a predominant compound in the C37 alkenone homologue. Based on regres- sion analysis of U37 -ratios and the average annual, seasonal K ’ (spring, summer, autumn, winter) temperatures, the linear K ’ relativity of U37 -ratios and mean annual temperatures is superior to the others, and the correlation coefficient is 0.88 (r2 = 0.88). The linear relationship of U37 and the average K ’ annual temperature in different water chemistry environ- K ’ ments suggests that the mechanisms controlling U37 index in the saline lakes might be the same as those in the ocean environment. The alkenone unsaturation could become an important paleotemperature proxy in the lacustrine envi- ronment.展开更多
To investigate the glutamate-like immunoreactivity (Glu-IR) changes in inner hair cells (IHCs) of guinea pigs cochlear after noise exposure. Guinea pigs were distributed into 6 groups including control group (g1), and...To investigate the glutamate-like immunoreactivity (Glu-IR) changes in inner hair cells (IHCs) of guinea pigs cochlear after noise exposure. Guinea pigs were distributed into 6 groups including control group (g1), and groups of immediately (g2), 8 hours (g3), 1 day (g4), 3 days (g5) and 7days (g6) after noise exposure. The experimental groups were exposed to 120 dBLp 1/3 octave 4 kHz narrow band noise for 4 hours to ruin the organ of Corti. The first turn of the organ of Corti was dissected to make ultrathin sections and under went immunoelectron study. The density of gold particles of Glu-IR in IHCs was measured. Results showed that Glu-IR in IHCs after noise exposure changed dynamically. The density of gold particle in IHCs of g2 significantly increased (p < 0.001) compared with gl and decreased in g3 (p < 0.001), whereas there were no significant difference in the groups of g4, g5 and g6 (p > 0.05). The results suggest that there may be glutamate autoreceptors in the membrane of IHCs and the glutamate released from pre-synapse may act on these autoreceptors in a postitive feedback manner, which induced [Ca2+] increased in IHCs immediately after noise exposure. Glutamate synthetase system was activated by Ca2+ and more glutamic acid was produced. In the group of 8 hours after noise exposure, glutamic acid decreased in IHCs because of its over-releasing into synapses. Glu-IR's recovery to normal level indicated that the glutamate-glutamine cycle may exist in guinea pig cochlea.展开更多
基金This project is supported by General Electric Corporate ResearchDevelopment and National Advanced Technology Project of China (No.863-511-942-018).
文摘A new method of extraction of blend surface feature is presented. It contains two steps: segmentation and recovery of parametric representation of the blend. The segmentation separates the points in the blend region from the rest of the input point cloud with the processes of sampling point data, estimation of local surface curvature properties and comparison of maximum curvature values. The recovery of parametric representation generates a set of profile curves by marching throughout the blend and fitting cylinders. Compared with the existing approaches of blend surface feature extraction, the proposed method reduces the requirement of user interaction and is capable of extracting blend surface with either constant radius or variable radius. Application examples are presented to verify the proposed method.
文摘The proxy of U37 index is widely applied to K ’ reconstructing paleotemperature in the marine environment. However, the long-chain alkenones (LCAs) research is rarely reported in the liminic system. In this paper, we studied LCAs in the surface sediments (0 —10 cm) of nine sulfate lakes in the Inner Mongolia Autonomous Region, Xinjiang Uygur Autonomous Region and Qinghai Province, China. LCAs are detected in eight of the nine lakes, except a dry salt lake —Lake Lop. The result shows that LCAs might be uni- versal in the sulfate lakes. In most of the surface samples, the sequence of the abundance of the long-chain alkenones is C37>C38>C39>C40. And C37︰4 methyl ketone is a predominant compound in the C37 alkenone homologue. Based on regres- sion analysis of U37 -ratios and the average annual, seasonal K ’ (spring, summer, autumn, winter) temperatures, the linear K ’ relativity of U37 -ratios and mean annual temperatures is superior to the others, and the correlation coefficient is 0.88 (r2 = 0.88). The linear relationship of U37 and the average K ’ annual temperature in different water chemistry environ- K ’ ments suggests that the mechanisms controlling U37 index in the saline lakes might be the same as those in the ocean environment. The alkenone unsaturation could become an important paleotemperature proxy in the lacustrine envi- ronment.
基金This work was supported by the National Natural Science Foundation of China (39870797).
文摘To investigate the glutamate-like immunoreactivity (Glu-IR) changes in inner hair cells (IHCs) of guinea pigs cochlear after noise exposure. Guinea pigs were distributed into 6 groups including control group (g1), and groups of immediately (g2), 8 hours (g3), 1 day (g4), 3 days (g5) and 7days (g6) after noise exposure. The experimental groups were exposed to 120 dBLp 1/3 octave 4 kHz narrow band noise for 4 hours to ruin the organ of Corti. The first turn of the organ of Corti was dissected to make ultrathin sections and under went immunoelectron study. The density of gold particles of Glu-IR in IHCs was measured. Results showed that Glu-IR in IHCs after noise exposure changed dynamically. The density of gold particle in IHCs of g2 significantly increased (p < 0.001) compared with gl and decreased in g3 (p < 0.001), whereas there were no significant difference in the groups of g4, g5 and g6 (p > 0.05). The results suggest that there may be glutamate autoreceptors in the membrane of IHCs and the glutamate released from pre-synapse may act on these autoreceptors in a postitive feedback manner, which induced [Ca2+] increased in IHCs immediately after noise exposure. Glutamate synthetase system was activated by Ca2+ and more glutamic acid was produced. In the group of 8 hours after noise exposure, glutamic acid decreased in IHCs because of its over-releasing into synapses. Glu-IR's recovery to normal level indicated that the glutamate-glutamine cycle may exist in guinea pig cochlea.
