Utilizing the acoustic emission(AE) technique, an experimental investigation into the damage evolution for steel strand under axial tension was described. The damage evolution model for steel stand relating the damage...Utilizing the acoustic emission(AE) technique, an experimental investigation into the damage evolution for steel strand under axial tension was described. The damage evolution model for steel stand relating the damage evolution to acoustic emission parameters was proposed by incorporating the AE rate process theory. The AE monitoring results indicate that damages occur in both elastic and plastic phases of steel strand. In elastic phase, AE signals are mainly sent out from the micro damage due to the surface friction among the wires of steel strand, while in plastic phase, AE signals emitted from the plastic deformation of wires. In addition, the AE cumulative parameters curves closely resemble the loading curve. The AE cumulative parameters curves can well describe the damage evolution process including the damage occurrence and damage development for steel strands. It is concluded that the AE technique is an effective and useful nondestructive technique for evaluating the damage characteristics of steel strand.展开更多
A case of strangulation of the transverse colon in a traumatic left diaphragmatic hernia manifesting as pericarditis is reported. This is unusual because pericardial signs in traumatic diaphragmatic hernia have been p...A case of strangulation of the transverse colon in a traumatic left diaphragmatic hernia manifesting as pericarditis is reported. This is unusual because pericardial signs in traumatic diaphragmatic hernia have been previously described in association with direct pericardial injury. This is the only such case where electrocardiographic changes of pericarditis were seen without direct pericardial trauma. The possibility of internal herniation through a traumatic diaphragmatic hernia must be considered in patients with chest symptoms and a compatible history.展开更多
A three-dimensional contact model of 1×7 steel strand was established. Contact point was searched by Splitting-pinball algorithm, and Augmented-Lagrangian algorithm was applied for analysis of contact loads. The ...A three-dimensional contact model of 1×7 steel strand was established. Contact point was searched by Splitting-pinball algorithm, and Augmented-Lagrangian algorithm was applied for analysis of contact loads. The exerted tensile loads to the model were analyzed using finite element method. After analyzing calculation results, the laws of steel wire stress distribution in axis direction and in its cross-section were found. Friction coefficients were set as 0.10, 0.11, and 0.12, respec- tively, to obtain the influence law of friction coefficient to steel wire stresses. Research result shows that friction coefficient has significant influence on the shear stress of steel wire. Analyzed the calculation results of steel strand with five different lay pitch multiples and got the influence law of lay pitch multiple to the stresses of steel wire in steel strand. The Von Misses stress of steel wire increases following with the increasing of lay pitches nmltiples, but the increment value is not very prominent. The shear stress of steel wire decreases following the increase of lay pitch multiple, and the changing amplitude is large when lay pitch multiple is small. Finally, carried out a steel strand tensile deformation test and the consistency of test results with the calculation results shows that the selected model is reasonable.展开更多
Objective： To evaluate the clinical effects of combined acupuncture and ear-puncture in treating renal colic. Methods： Sixty subjects were randomized into an acupuncture group and a medication group, 30 in each, to ...Objective： To evaluate the clinical effects of combined acupuncture and ear-puncture in treating renal colic. Methods： Sixty subjects were randomized into an acupuncture group and a medication group, 30 in each, to receive acupuncture and Western medicine respectively. The analgesic effects and pain relief time were measured in both groups. Results： Both of the two groups got pain relieved or reduced. The total effective rate was 89.7% in the acupuncture group, significantly superior to 77.4% in the medication group （P〈0.05）. Conclusion： Combined body and auricular acupuncture is efficient in relieving pain in treating renal colic, and its effective rate was higher compared with medication treatment.展开更多
The difficulty to select the best system parameters restricts the engineering application of stochastic resonance （SR）. An adaptive cascade stochastic resonance （ACSR） is proposed in the present study. The propose...The difficulty to select the best system parameters restricts the engineering application of stochastic resonance （SR）. An adaptive cascade stochastic resonance （ACSR） is proposed in the present study. The proposed method introduces correlation theory into SR, and uses correlation coefficient of the input signals and noise as a weight to construct the weighted signal-to-noise ratio （WSNR） index. The influence of high frequency noise is alleviated and the signal-to-noise ratio index used in traditional SR is improved accordingly. The ACSR with WSNR can obtain optimal parameters adaptively. And it is not necessary to predict the exact frequency of the target signal. In addition, through the secondary utilization of noise, ACSR makes the signal output waveforrn smoother and the fluctuation period more obvious. Simulation example and engineering application of gearbox fault diagnosis demonstrate the effectiveness and feasibility of the proposed method.展开更多
基金Projects(51308073,51378081)supported by the National Natural Science Foundation of ChinaProject(20124316120002)supported by PhD Programs Foundation of Ministry of Education of China+1 种基金Project(12KB02)supported by the Key Laboratory for Safety Control of Bridge Engineering of Ministry of Education of ChinaProject(14JJ3087)supported by the Science Foundation of Hunan Province,China
文摘Utilizing the acoustic emission(AE) technique, an experimental investigation into the damage evolution for steel strand under axial tension was described. The damage evolution model for steel stand relating the damage evolution to acoustic emission parameters was proposed by incorporating the AE rate process theory. The AE monitoring results indicate that damages occur in both elastic and plastic phases of steel strand. In elastic phase, AE signals are mainly sent out from the micro damage due to the surface friction among the wires of steel strand, while in plastic phase, AE signals emitted from the plastic deformation of wires. In addition, the AE cumulative parameters curves closely resemble the loading curve. The AE cumulative parameters curves can well describe the damage evolution process including the damage occurrence and damage development for steel strands. It is concluded that the AE technique is an effective and useful nondestructive technique for evaluating the damage characteristics of steel strand.
文摘A case of strangulation of the transverse colon in a traumatic left diaphragmatic hernia manifesting as pericarditis is reported. This is unusual because pericardial signs in traumatic diaphragmatic hernia have been previously described in association with direct pericardial injury. This is the only such case where electrocardiographic changes of pericarditis were seen without direct pericardial trauma. The possibility of internal herniation through a traumatic diaphragmatic hernia must be considered in patients with chest symptoms and a compatible history.
文摘A three-dimensional contact model of 1×7 steel strand was established. Contact point was searched by Splitting-pinball algorithm, and Augmented-Lagrangian algorithm was applied for analysis of contact loads. The exerted tensile loads to the model were analyzed using finite element method. After analyzing calculation results, the laws of steel wire stress distribution in axis direction and in its cross-section were found. Friction coefficients were set as 0.10, 0.11, and 0.12, respec- tively, to obtain the influence law of friction coefficient to steel wire stresses. Research result shows that friction coefficient has significant influence on the shear stress of steel wire. Analyzed the calculation results of steel strand with five different lay pitch multiples and got the influence law of lay pitch multiple to the stresses of steel wire in steel strand. The Von Misses stress of steel wire increases following with the increasing of lay pitches nmltiples, but the increment value is not very prominent. The shear stress of steel wire decreases following the increase of lay pitch multiple, and the changing amplitude is large when lay pitch multiple is small. Finally, carried out a steel strand tensile deformation test and the consistency of test results with the calculation results shows that the selected model is reasonable.
文摘Objective： To evaluate the clinical effects of combined acupuncture and ear-puncture in treating renal colic. Methods： Sixty subjects were randomized into an acupuncture group and a medication group, 30 in each, to receive acupuncture and Western medicine respectively. The analgesic effects and pain relief time were measured in both groups. Results： Both of the two groups got pain relieved or reduced. The total effective rate was 89.7% in the acupuncture group, significantly superior to 77.4% in the medication group （P〈0.05）. Conclusion： Combined body and auricular acupuncture is efficient in relieving pain in treating renal colic, and its effective rate was higher compared with medication treatment.
基金supported by the National Basic Research Program of China ("973" Program) (Grant No. 2011CB706805)the National Natural Science Foundation of China (Grant No. 51035007)
文摘The difficulty to select the best system parameters restricts the engineering application of stochastic resonance （SR）. An adaptive cascade stochastic resonance （ACSR） is proposed in the present study. The proposed method introduces correlation theory into SR, and uses correlation coefficient of the input signals and noise as a weight to construct the weighted signal-to-noise ratio （WSNR） index. The influence of high frequency noise is alleviated and the signal-to-noise ratio index used in traditional SR is improved accordingly. The ACSR with WSNR can obtain optimal parameters adaptively. And it is not necessary to predict the exact frequency of the target signal. In addition, through the secondary utilization of noise, ACSR makes the signal output waveforrn smoother and the fluctuation period more obvious. Simulation example and engineering application of gearbox fault diagnosis demonstrate the effectiveness and feasibility of the proposed method.
