In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total...In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.展开更多
There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute thre...There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute three-stage hierarchy of particles, atoms, and gravitational systems. Below 1/c waves are dissociated into strands and neutrinos are separated as points of charge. The electron and positron are single strands with opposed helical turns. Protons and neutrons have a nucleus of positrinos and negatrinos surrounded by concentric shells of strands in 2"~ resonance. The orbital strands reverberate into space creating a field with gravitational and electromagnetic aspects. The orbital system defines matter, energy, motion, and time based on composition. The three stages have a constant field content but differ by field density and components.展开更多
We are developing a nursing-care robot for physical care tasks. The concept of this robot is to promote the cared persons by the robot to activate their own motion ability as long as possible. This may lead to the imp...We are developing a nursing-care robot for physical care tasks. The concept of this robot is to promote the cared persons by the robot to activate their own motion ability as long as possible. This may lead to the improvement of the cared person's movement volition and movement abilities. In order to realize safe and human friendly robot care tasks, full body manipulation is an important technology, for which it is necessary to estimate the subject's center of gravity from the contact positions and forces with the robot's two arms. In this paper, we estimate the center of gravity of object based on the contact point and the contact force estimated by force sensor on both robot arms. The position of gravity center is important to realize care tasks stably. We performed experiments and simulations for the single point contact and dual points contact cases using a cylindrical object. As a result, it is found that although some errors were recognized in the experiments compared with the simulations, the relations between the contact positions and such errors were observed. Such experimental error mainly comes from the difference of shape between the real robot and the model of the robot in simulation.展开更多
Objective To explore the effect of moxibustion at Shenque (神阙 CV 8) on the anti-exercise-induced fatigue in rats after exhaustive exercise in varying degrees. Methods Seventy-two SD rats were randomly divided int...Objective To explore the effect of moxibustion at Shenque (神阙 CV 8) on the anti-exercise-induced fatigue in rats after exhaustive exercise in varying degrees. Methods Seventy-two SD rats were randomly divided into 3 groups according to the random number table method, including blank group, model group and moxibustion group. The model group and moxibustion group were divided into 4 subgroups respectively, that was 1 time, 4 times, 7 times and 10 times subgroup. There were 9 groups with 8 rats in each group. Except blank group, all the rats were established into exhaustive models through swimming. Mild moxibustion at CV 8 was carried out for 15 min in the rats in moxibustion group after modeling for once every other day. The concentration of serum glucose (GLU), malonaldehyde (MDA) and blood urea nitrogen (BUN) as well as the activity of aspartate transaminase (AST), alanine transaminase (ALT) and lactic dehydrogenase (LDH) were detected 24h after the exhaustive exercise by adopting full-automatic analyzer. Results The exhaustive time of rats were long at first but shorter later. The exhaustive time of rats in the model group (4 times) were obviously longer than that in the model group (1 time) (P〈0.01), the exhaustive time of rats in the model group (7 times) and model group (10 times) were obviously shorter than that in the model group (1 time) (P〈0.01), and the exhaustive time of rats in the moxibustion group (7 times) and moxibustion group (10 times) were obviously longer than that in the model group with the same number of times (P〈0.01), the serum GLU level of rats in the model group (7 times) and model group (10 times) increased when compared with the blank group (P〈0.01), and the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of rats in the model group (4 times), model group (7 times) and model group (10 times) increased when compared with the blank group (P〈0.05 or P〈0.01), the serum GLU, MDA and BNU levels as well as the activity of AST and ALT of rats in the moxibustion group (7 times) and moxibustion group (10 times) reduced when compared with the model group with the same number of times (P〈0.05 or P〈0.01), and the serum LDH activity of rats in the moxibustion group (4 times), moxibustion group (7 times) and moxibustion group (10 times) reduced when compared with the model group with the same number of times (P〈0.05 or P〈0.01). Conclusion Moxibustion at CV 8 can reduce the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of organism in a status of long-term fatigue, effectively improve the symptom of long-term fatigue, providing a certain experimental basis for the clinical application of moxibustion at CV 8 in the process of anti-exercise-induced fatigue in the future.展开更多
The present paper does an experimental and numerical investigation of the hydrodynamic interaction and the response of a single point turret-moored Floating Liquefied Natural Gas(FLNG) system,which is a new type of fl...The present paper does an experimental and numerical investigation of the hydrodynamic interaction and the response of a single point turret-moored Floating Liquefied Natural Gas(FLNG) system,which is a new type of floating LNG(Liquid Natural Gas) platform that consists of a ship-type FPSO hull equipped with LNG storage tanks and liquefaction plants.In particular,this study focuses on the investigation of the roll response of FLNG hull in free-decay motions,white noise waves and also in irregular waves.Model tests of the FLNG system in 60%H filling condition excited by both white noise waves and irregular waves combined with steady wind and current have been carried out.Response Amplitude Operators(RAOs) and time histories of the responses are obtained for sway,roll and yaw motions.Obvious Low Frequency(LF) components of the roll motions are observed,which may be out of expectation.To facilitate the physical understanding of this phenomenon,we filter the roll motions at the period of 30 s into two parts:the Wave Frequency(WF) motions and the Low Frequency(LF) motions respectively.The results indicate that the LF motions are closely related to the sway and yaw motions.Possible reasons for the presence of the LF motions of roll have been discussed in detail,through the comparison with the sway and yaw motions.As for the numerical part,the simulation of the modeled case is conducted with the help of the software SESAM.A good agreement between experiments and calculations is reported within the scope of trends.However,the numerical simulations should be further improved for the prediction of the FLNG system in the heading sea.展开更多
Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical "digital fish" database...Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical "digital fish" database for some typical fish species. Accord- ingly, based on the control framework of "Neural Control - Active Contraction of Muscle - Passive Deformation", the elec- tromyography (EMG) signals, the mechanical properties and the constitutive relationship of skin, muscle, and body trunk, as well as morphological parameters of crucian carp, are investigated with experiments, from which a simplified database of bio- mechanical "digital fish" is established. First, the EMG signals from three lateral superficial red muscles of crucian carp, which was evolving in the C-start movement, were acquired with a self-designing amplifier. The modes of muscle activity were also investigated. Secondly, the Young's modulus and the reduced relaxation function of crucian carp's skin and muscle were de- termined by failure tests and relaxation tests in uniaxial tensile ways, respectively. Viscoelastic models were adopted to deduce the constitutive relationship. The mechanical properties and the angular stiffness of different sites on the crucian carp's body trunk were obtained with dynamic bending experiments, where a self-designing dynamic bending test machine was employed. The conclusion was drawn regarding the body trunk of crucian carp under dynamic bending deformation as an approximate elastomer. According to the above experimental results, a possible benefit of body effective stiffness increasing with a little energy dissipation was discussed. Thirdly, the distribution of geometric parameters and weight parameters for a single experi- mental individual and multiple individuals of crucian carp was studied with experiments. Finally, considering all the above re- suits, generic experimental data were obtained by normalization, and a preliminary biomechanical "digital fish" database for crucian carp was established.展开更多
An analysis is carried out to study the steady flow characteristics from a continuous flat surface moving in a parallel free stream of non-Newtonian power law fluid. The constitutive equations of the fluid are transfo...An analysis is carried out to study the steady flow characteristics from a continuous flat surface moving in a parallel free stream of non-Newtonian power law fluid. The constitutive equations of the fluid are transformed into dimensionless ones. The velocity field is measured by Particle Image Velocimetry. Experimental results are obtained for the distribution of velocity. The influence of wall velocity ratio parameter on boundary layer flow field is observed in the experiment. Dimensionless velocity distribution and shearing stress distribution are obtained by post-processing experimental results. The effects of various physical parameters like velocity ratio parameter and similarity variable on various momentum transfer characteristics are discussed in detail and shown graphically. It is indicated that dimensionless velocity increases with velocity ratio parameter and similarity variable, and that dimensionless shearing stress decreases with velocity ratio parameter and similarity variable.展开更多
文摘In this paper, towing tank experiments are conducted to study the behavior of flow on a model of the underwater vehicle with various shapes of bows, i.e. tango and standard bows in free surface motion tests. The total resistances for different Froude numbers are considered experimentally. The towing tank is equipped with a trolley that can operate in through 0.05-6 m/s speed with ±0.02 m/s accuracy. Furthermore, the study is done on hydrodynamic coefficients i.e. total, residual and friction resistance coefficients, and the results are compared. Finally, the study on flow of wave fields around bows is done and wave filed around two bows are compared. The Froude number interval is between 0.099 and 0.349. Blockage fraction for the model is fixed to 0.005 3. The results showed that the residual resistance of the standard bow in 0.19 to 0.3 Froude number is more than the tango bow in surface motion which causes more total resistance for the submarine. Finally, details of wave generated by the bow are depicted and the effects of flow pattern on resistance drag are discussed.
文摘There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute three-stage hierarchy of particles, atoms, and gravitational systems. Below 1/c waves are dissociated into strands and neutrinos are separated as points of charge. The electron and positron are single strands with opposed helical turns. Protons and neutrons have a nucleus of positrinos and negatrinos surrounded by concentric shells of strands in 2"~ resonance. The orbital strands reverberate into space creating a field with gravitational and electromagnetic aspects. The orbital system defines matter, energy, motion, and time based on composition. The three stages have a constant field content but differ by field density and components.
文摘We are developing a nursing-care robot for physical care tasks. The concept of this robot is to promote the cared persons by the robot to activate their own motion ability as long as possible. This may lead to the improvement of the cared person's movement volition and movement abilities. In order to realize safe and human friendly robot care tasks, full body manipulation is an important technology, for which it is necessary to estimate the subject's center of gravity from the contact positions and forces with the robot's two arms. In this paper, we estimate the center of gravity of object based on the contact point and the contact force estimated by force sensor on both robot arms. The position of gravity center is important to realize care tasks stably. We performed experiments and simulations for the single point contact and dual points contact cases using a cylindrical object. As a result, it is found that although some errors were recognized in the experiments compared with the simulations, the relations between the contact positions and such errors were observed. Such experimental error mainly comes from the difference of shape between the real robot and the model of the robot in simulation.
基金Supported by Natural Science Fund Project of Youth of Hebei Education Department:QN2016021Key Scientific Project of Administration of Traditional Chinese Medicine of Hebei Province:2016011 and 2017011
文摘Objective To explore the effect of moxibustion at Shenque (神阙 CV 8) on the anti-exercise-induced fatigue in rats after exhaustive exercise in varying degrees. Methods Seventy-two SD rats were randomly divided into 3 groups according to the random number table method, including blank group, model group and moxibustion group. The model group and moxibustion group were divided into 4 subgroups respectively, that was 1 time, 4 times, 7 times and 10 times subgroup. There were 9 groups with 8 rats in each group. Except blank group, all the rats were established into exhaustive models through swimming. Mild moxibustion at CV 8 was carried out for 15 min in the rats in moxibustion group after modeling for once every other day. The concentration of serum glucose (GLU), malonaldehyde (MDA) and blood urea nitrogen (BUN) as well as the activity of aspartate transaminase (AST), alanine transaminase (ALT) and lactic dehydrogenase (LDH) were detected 24h after the exhaustive exercise by adopting full-automatic analyzer. Results The exhaustive time of rats were long at first but shorter later. The exhaustive time of rats in the model group (4 times) were obviously longer than that in the model group (1 time) (P〈0.01), the exhaustive time of rats in the model group (7 times) and model group (10 times) were obviously shorter than that in the model group (1 time) (P〈0.01), and the exhaustive time of rats in the moxibustion group (7 times) and moxibustion group (10 times) were obviously longer than that in the model group with the same number of times (P〈0.01), the serum GLU level of rats in the model group (7 times) and model group (10 times) increased when compared with the blank group (P〈0.01), and the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of rats in the model group (4 times), model group (7 times) and model group (10 times) increased when compared with the blank group (P〈0.05 or P〈0.01), the serum GLU, MDA and BNU levels as well as the activity of AST and ALT of rats in the moxibustion group (7 times) and moxibustion group (10 times) reduced when compared with the model group with the same number of times (P〈0.05 or P〈0.01), and the serum LDH activity of rats in the moxibustion group (4 times), moxibustion group (7 times) and moxibustion group (10 times) reduced when compared with the model group with the same number of times (P〈0.05 or P〈0.01). Conclusion Moxibustion at CV 8 can reduce the serum MDA and BNU levels as well as the activity of AST, ALT and LDH of organism in a status of long-term fatigue, effectively improve the symptom of long-term fatigue, providing a certain experimental basis for the clinical application of moxibustion at CV 8 in the process of anti-exercise-induced fatigue in the future.
基金supported by the Science Foundation of Science and Technology Commission of Shanghai Municipality(Grant No.11ZR1417800)the National Natural Science Foundation of China(Grant No.50879045)the LRET(Lloyds Register Educational Trust) to the joint centre involving University College London,Shanghai Jiao Tong University and Harbin Engineering University
文摘The present paper does an experimental and numerical investigation of the hydrodynamic interaction and the response of a single point turret-moored Floating Liquefied Natural Gas(FLNG) system,which is a new type of floating LNG(Liquid Natural Gas) platform that consists of a ship-type FPSO hull equipped with LNG storage tanks and liquefaction plants.In particular,this study focuses on the investigation of the roll response of FLNG hull in free-decay motions,white noise waves and also in irregular waves.Model tests of the FLNG system in 60%H filling condition excited by both white noise waves and irregular waves combined with steady wind and current have been carried out.Response Amplitude Operators(RAOs) and time histories of the responses are obtained for sway,roll and yaw motions.Obvious Low Frequency(LF) components of the roll motions are observed,which may be out of expectation.To facilitate the physical understanding of this phenomenon,we filter the roll motions at the period of 30 s into two parts:the Wave Frequency(WF) motions and the Low Frequency(LF) motions respectively.The results indicate that the LF motions are closely related to the sway and yaw motions.Possible reasons for the presence of the LF motions of roll have been discussed in detail,through the comparison with the sway and yaw motions.As for the numerical part,the simulation of the modeled case is conducted with the help of the software SESAM.A good agreement between experiments and calculations is reported within the scope of trends.However,the numerical simulations should be further improved for the prediction of the FLNG system in the heading sea.
基金supported by the National Natural Science Foundation of China (Grant No. 10832010)the Knowledge Innovation Project of the Chinese Academy of Sciences (Grant No. KJCX2-YW-L05)
文摘Currently, the integrated biomechanical studies on fish locomotion come into focus, so it is urgent to provide reliable and sys- tematic experimental results, and to establish a biomechanical "digital fish" database for some typical fish species. Accord- ingly, based on the control framework of "Neural Control - Active Contraction of Muscle - Passive Deformation", the elec- tromyography (EMG) signals, the mechanical properties and the constitutive relationship of skin, muscle, and body trunk, as well as morphological parameters of crucian carp, are investigated with experiments, from which a simplified database of bio- mechanical "digital fish" is established. First, the EMG signals from three lateral superficial red muscles of crucian carp, which was evolving in the C-start movement, were acquired with a self-designing amplifier. The modes of muscle activity were also investigated. Secondly, the Young's modulus and the reduced relaxation function of crucian carp's skin and muscle were de- termined by failure tests and relaxation tests in uniaxial tensile ways, respectively. Viscoelastic models were adopted to deduce the constitutive relationship. The mechanical properties and the angular stiffness of different sites on the crucian carp's body trunk were obtained with dynamic bending experiments, where a self-designing dynamic bending test machine was employed. The conclusion was drawn regarding the body trunk of crucian carp under dynamic bending deformation as an approximate elastomer. According to the above experimental results, a possible benefit of body effective stiffness increasing with a little energy dissipation was discussed. Thirdly, the distribution of geometric parameters and weight parameters for a single experi- mental individual and multiple individuals of crucian carp was studied with experiments. Finally, considering all the above re- suits, generic experimental data were obtained by normalization, and a preliminary biomechanical "digital fish" database for crucian carp was established.
基金supported by the National Natural Science Foundation of China (No. 50476083)
文摘An analysis is carried out to study the steady flow characteristics from a continuous flat surface moving in a parallel free stream of non-Newtonian power law fluid. The constitutive equations of the fluid are transformed into dimensionless ones. The velocity field is measured by Particle Image Velocimetry. Experimental results are obtained for the distribution of velocity. The influence of wall velocity ratio parameter on boundary layer flow field is observed in the experiment. Dimensionless velocity distribution and shearing stress distribution are obtained by post-processing experimental results. The effects of various physical parameters like velocity ratio parameter and similarity variable on various momentum transfer characteristics are discussed in detail and shown graphically. It is indicated that dimensionless velocity increases with velocity ratio parameter and similarity variable, and that dimensionless shearing stress decreases with velocity ratio parameter and similarity variable.