Lateral intakes are common in rivers.The pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division width.The hydraulic characteristics of lateral withdrawa...Lateral intakes are common in rivers.The pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division width.The hydraulic characteristics of lateral withdrawal from inclined river slopes at different intake elevations should be investigated.Meanwhile,the division width exhibits significant vertical non-uniformity at an inclined river slope,which should be clarified.Hence,a three-dimensional(3-D)hydrodynamic and particle-tracking model was developed with the Open Source Field Operation and Manipulation(Open FOAM),and the model was validated with physical model tests for 90°lateral withdrawal from an inclined side bank.The flow fields,withdrawal sources,and division widths were investigated with different intake bottom elevations,withdrawal discharges,and main channel velocities.This study showed that under inclined side bank conditions,water entered the intake at an oblique angle,causing significant 3-D spiral flows in the intake rather than two-dimensional closed recirculation.A lower withdrawal discharge,a lower bottom elevation of the intake,or a higher main channel velocity could further strengthen this phenomenon.The average division width and turbulent kinetic energy were smaller under inclined side bank conditions than under vertical bank conditions.With a low intake bottom elevation,a low withdrawal discharge,or a high main channel velocity,the sources of lateral withdrawal were in similar ranges near the local inclined bank in the vertical direction.Under inclined slope conditions,sediment deposition near the intake entrance could be reduced,compared to that under vertical slope conditions.The results provide hydrodynamic and sediment references for engineering designs for natural rivers with inclined terrains.展开更多
This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area（LHA） in obese...This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area（LHA） in obese rats in order to find the optimal stimulation parameter and location. Eight gastric electrical stimulations（GES） with different parameters were performed and the neuronal activities of gastric-distension responsive（GD-R） neurons in LHA were observed. The effects of stimulations with 8 parameters were compared to find the optimal parameter. Then the optimal parameter was used to perform electrical stimulation at duodenum and ileum, and the effects of the duodenal and ileac stimulation on the GD-R neurons in LHA were compared with the gastric stimulation of optimal parameter. The results showed that GES with the lowest energy parameter（0.3 ms, 3 mA, 20 Hz, 2 s on, 3 s off） activated the least neurons. The effects of GES with other parameters whose pulse width was 0.3 ms were not significantly different from those of the lowest energy parameter. Most gastric stimulations whose pulse width was 3 ms activated more LHA neurons than the smallest energy parameter stimulation, and the effects of those 3 ms gastric stimulations were similar. Accordingly, the lowest energy parameter was recognized as the optimal parameter. The effects of stimulations with the optimal parameter at stomach, duodenum and ileum on the LHA neuronal activities were not different. Collectively, gastrointestinal electrical stimulation（GIES） with relatively large pulse width might have stronger effects to the neuronal activities of GD-R neurons in LHA of obese rats. The effects of the GIES at different locations（stomach, duodenum and ileum） on those neurons are similar, and GES is preferential because of its easy clinical performance and safety.展开更多
Previous reports have suggested that hypothalamic urocortin 1 (Ucn1) exerts inhibitory control on energy metabolism as direct paraventricular nucleus injections dose-dependently decrease the respiratory energy exchang...Previous reports have suggested that hypothalamic urocortin 1 (Ucn1) exerts inhibitory control on energy metabolism as direct paraventricular nucleus injections dose-dependently decrease the respiratory energy exchange ratio (RER). Other evidence indicates that Ucn1 injections into the lateral septum may alter metabolic function. Consequently, the present study was designed to further characterize the effects of lateral septal Ucn1 signaling on eating and energy metabolism of adult Sprague-Dawley rats. Ucn1 was infused at the onset of the nocturnal cycle at doses of 10 - 100 pmol. In both females and males the peptide elicited a reliable suppression of food intake and significantly lowered RER over a 4 h postinjection period. The decrease in RER is consistent with enhanced lipid oxidation. Overall these findings suggest that, similar to the paraventricular nucleus, the lateral septum is a critical site of action in mediating the effects of Ucn1 on food intake and energy substrate utilization.展开更多
The eclipsed form arrangement and march-past method of water intake-outlet arrangements in power plants were researched by 3-D numerical simulation based on the k-e two-equation turbulence model. Firstly, the flowing ...The eclipsed form arrangement and march-past method of water intake-outlet arrangements in power plants were researched by 3-D numerical simulation based on the k-e two-equation turbulence model. Firstly, the flowing characteristics of eclipsed form arrangement were analyzed and the effects of some main factors on inlet temperature were investigated. The simulation results are basically in agreement with those of the previous experiments. Then, by comparing the inlet temperature of the above two intake-outlet methods, the superiority and its existent conditions of the eclipsed form were examined.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52379061)the Natural Science Foundation of Jiangsu Province(Grant No.BK20230099)the Key Laboratory of Water Grid Project and Regulation of Ministry of Water Resources(Grant No.QTKS0034W23292).
文摘Lateral intakes are common in rivers.The pump effciency and sediment deposition are determined by the local hydrodynamic characteristics and mainstream division width.The hydraulic characteristics of lateral withdrawal from inclined river slopes at different intake elevations should be investigated.Meanwhile,the division width exhibits significant vertical non-uniformity at an inclined river slope,which should be clarified.Hence,a three-dimensional(3-D)hydrodynamic and particle-tracking model was developed with the Open Source Field Operation and Manipulation(Open FOAM),and the model was validated with physical model tests for 90°lateral withdrawal from an inclined side bank.The flow fields,withdrawal sources,and division widths were investigated with different intake bottom elevations,withdrawal discharges,and main channel velocities.This study showed that under inclined side bank conditions,water entered the intake at an oblique angle,causing significant 3-D spiral flows in the intake rather than two-dimensional closed recirculation.A lower withdrawal discharge,a lower bottom elevation of the intake,or a higher main channel velocity could further strengthen this phenomenon.The average division width and turbulent kinetic energy were smaller under inclined side bank conditions than under vertical bank conditions.With a low intake bottom elevation,a low withdrawal discharge,or a high main channel velocity,the sources of lateral withdrawal were in similar ranges near the local inclined bank in the vertical direction.Under inclined slope conditions,sediment deposition near the intake entrance could be reduced,compared to that under vertical slope conditions.The results provide hydrodynamic and sediment references for engineering designs for natural rivers with inclined terrains.
基金financially supported by National Natural Science Foundation of China(No.30870927)
文摘This study tested the effects of the gastrointestinal pulse train electrical stimulation with different parameters and at different locations on the neuronal activities of the lateral hypothalamus area（LHA） in obese rats in order to find the optimal stimulation parameter and location. Eight gastric electrical stimulations（GES） with different parameters were performed and the neuronal activities of gastric-distension responsive（GD-R） neurons in LHA were observed. The effects of stimulations with 8 parameters were compared to find the optimal parameter. Then the optimal parameter was used to perform electrical stimulation at duodenum and ileum, and the effects of the duodenal and ileac stimulation on the GD-R neurons in LHA were compared with the gastric stimulation of optimal parameter. The results showed that GES with the lowest energy parameter（0.3 ms, 3 mA, 20 Hz, 2 s on, 3 s off） activated the least neurons. The effects of GES with other parameters whose pulse width was 0.3 ms were not significantly different from those of the lowest energy parameter. Most gastric stimulations whose pulse width was 3 ms activated more LHA neurons than the smallest energy parameter stimulation, and the effects of those 3 ms gastric stimulations were similar. Accordingly, the lowest energy parameter was recognized as the optimal parameter. The effects of stimulations with the optimal parameter at stomach, duodenum and ileum on the LHA neuronal activities were not different. Collectively, gastrointestinal electrical stimulation（GIES） with relatively large pulse width might have stronger effects to the neuronal activities of GD-R neurons in LHA of obese rats. The effects of the GIES at different locations（stomach, duodenum and ileum） on those neurons are similar, and GES is preferential because of its easy clinical performance and safety.
文摘Previous reports have suggested that hypothalamic urocortin 1 (Ucn1) exerts inhibitory control on energy metabolism as direct paraventricular nucleus injections dose-dependently decrease the respiratory energy exchange ratio (RER). Other evidence indicates that Ucn1 injections into the lateral septum may alter metabolic function. Consequently, the present study was designed to further characterize the effects of lateral septal Ucn1 signaling on eating and energy metabolism of adult Sprague-Dawley rats. Ucn1 was infused at the onset of the nocturnal cycle at doses of 10 - 100 pmol. In both females and males the peptide elicited a reliable suppression of food intake and significantly lowered RER over a 4 h postinjection period. The decrease in RER is consistent with enhanced lipid oxidation. Overall these findings suggest that, similar to the paraventricular nucleus, the lateral septum is a critical site of action in mediating the effects of Ucn1 on food intake and energy substrate utilization.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10272044,10672056).
文摘The eclipsed form arrangement and march-past method of water intake-outlet arrangements in power plants were researched by 3-D numerical simulation based on the k-e two-equation turbulence model. Firstly, the flowing characteristics of eclipsed form arrangement were analyzed and the effects of some main factors on inlet temperature were investigated. The simulation results are basically in agreement with those of the previous experiments. Then, by comparing the inlet temperature of the above two intake-outlet methods, the superiority and its existent conditions of the eclipsed form were examined.
