In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.Theseongoing research efforts are motivated by more pervasive applications of such vehicles including s...In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.Theseongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations,scientific deep ocean surveys,military purposes,ecological and water environmental studies,and also entertainments.However,the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency andmaneuverability.The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrustforces which make the control of the position and motion difficult.On the other hand,fishes and other aquatic animals are efficient swimmers,posses high maneuverability,are able to followtrajectories,can efficiently stabilize themselves in currents and surges,create less wakes than currently used underwater vehicle,and also have a noiseless propulsion.The fish’s locomotion mechanism is mainly controlled by its caudal fin and paired pectoralfins.They are classified into Body and/or Caudal Fin(BCF)and Median and/or paired Pectoral Fins(MPF).The study of highlyefficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism.There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster.The work presented in thispaper represents a contribution in this area covering study,design and implementation of locomotion mechanisms of pairedpectoral fins in a fish robot.The performance and viability of the biomimetic method for underwater vehicles are highlightedthrough in-water experiment of a robotic fish.展开更多
Approximately 200 mg of fin tissue from each specimen was cut into pieces and treated with a gradient of ethanol (65%, 70%, 75%, 80%, 85%, 90%, 95% and 100%) and then DNA was extracted from formalin fish fin tissues. ...Approximately 200 mg of fin tissue from each specimen was cut into pieces and treated with a gradient of ethanol (65%, 70%, 75%, 80%, 85%, 90%, 95% and 100%) and then DNA was extracted from formalin fish fin tissues. Agarose gel visualization of the DNA confirmed DNA extracted. MtDNA cyt b gene banding pattern of samples with agarose gel was clearly visible and could be used to be sequenced. In terms of DNA purity, the 260/280 ratio of 87.5% samples ranged between 1.8 and 2.0, indicating that DNA of the majority of the samples was pure. The developed DNA extraction procedure from formalin fish fin tissues by pretreatment with a gradient of ethanol system will be a useful tool to study the genetic structure and phylogenesis of endangered fish, by specimens preserved formalin-fixed in museum and herbarium.展开更多
PCR has been a general preferred method for biological research in fish,and previous research have enabled us to extract and purify PCR-quality DNA templates in laboratories [1-4].The same problem among these procedur...PCR has been a general preferred method for biological research in fish,and previous research have enabled us to extract and purify PCR-quality DNA templates in laboratories [1-4].The same problem among these procedures is waiting for tissue digesting for a long time.The overabundance time spent on PCR-quality DNA extraction restricts the efficiency of PCR assay,especially in large-scale PCR amplification,such as SSR-based genetic-mapping construction [5,6],identification of germ plasm resource[7,8] and evolution research [9,10],etc.In this study,a stable and rapid PCR-quality DNA extraction method was explored,using a modified alkaline lysis protocol.Extracting DNA for PCR only takes approximately 25 minutes.This stable and rapid DNA extraction method could save much laboratory time and promotes.展开更多
A robotic fish driven by oscillating fins, "Cownose Ray-I", is developed, which is in dorsoventrally flattened shape withouta tail. The robotic fish is composed of a body and two lateral fins. A three-factor...A robotic fish driven by oscillating fins, "Cownose Ray-I", is developed, which is in dorsoventrally flattened shape withouta tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in thedesign of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forwardvelocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beatfrequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results onmaneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition,as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s<sup>-1</sup>.展开更多
文摘In present,there are increasing interests in the research on mechanical and control system of underwater vehicles.Theseongoing research efforts are motivated by more pervasive applications of such vehicles including seabed oil and gas explorations,scientific deep ocean surveys,military purposes,ecological and water environmental studies,and also entertainments.However,the performance of underwater vehicles with screw type propellers is not prospective in terms of its efficiency andmaneuverability.The main weaknesses of this kind of propellers are the production of vortices and sudden generation of thrustforces which make the control of the position and motion difficult.On the other hand,fishes and other aquatic animals are efficient swimmers,posses high maneuverability,are able to followtrajectories,can efficiently stabilize themselves in currents and surges,create less wakes than currently used underwater vehicle,and also have a noiseless propulsion.The fish’s locomotion mechanism is mainly controlled by its caudal fin and paired pectoralfins.They are classified into Body and/or Caudal Fin(BCF)and Median and/or paired Pectoral Fins(MPF).The study of highlyefficient swimming mechanisms of fish can inspire a better underwater vehicles thruster design and its mechanism.There are few studies on underwater vehicles or fish robots using paired pectoral fins as thruster.The work presented in thispaper represents a contribution in this area covering study,design and implementation of locomotion mechanisms of pairedpectoral fins in a fish robot.The performance and viability of the biomimetic method for underwater vehicles are highlightedthrough in-water experiment of a robotic fish.
文摘Approximately 200 mg of fin tissue from each specimen was cut into pieces and treated with a gradient of ethanol (65%, 70%, 75%, 80%, 85%, 90%, 95% and 100%) and then DNA was extracted from formalin fish fin tissues. Agarose gel visualization of the DNA confirmed DNA extracted. MtDNA cyt b gene banding pattern of samples with agarose gel was clearly visible and could be used to be sequenced. In terms of DNA purity, the 260/280 ratio of 87.5% samples ranged between 1.8 and 2.0, indicating that DNA of the majority of the samples was pure. The developed DNA extraction procedure from formalin fish fin tissues by pretreatment with a gradient of ethanol system will be a useful tool to study the genetic structure and phylogenesis of endangered fish, by specimens preserved formalin-fixed in museum and herbarium.
基金Special Fund for Agro-scientific Research in the Public Interest:200903045Natural Science Foundation of China:31101894
文摘PCR has been a general preferred method for biological research in fish,and previous research have enabled us to extract and purify PCR-quality DNA templates in laboratories [1-4].The same problem among these procedures is waiting for tissue digesting for a long time.The overabundance time spent on PCR-quality DNA extraction restricts the efficiency of PCR assay,especially in large-scale PCR amplification,such as SSR-based genetic-mapping construction [5,6],identification of germ plasm resource[7,8] and evolution research [9,10],etc.In this study,a stable and rapid PCR-quality DNA extraction method was explored,using a modified alkaline lysis protocol.Extracting DNA for PCR only takes approximately 25 minutes.This stable and rapid DNA extraction method could save much laboratory time and promotes.
基金The supports of National Natural Science Foundation of China (No.50405006)the supports of the innovation foundation of graduate students of National University of Defense Technology (No.B060302) are also gratefully acknowledged
文摘A robotic fish driven by oscillating fins, "Cownose Ray-I", is developed, which is in dorsoventrally flattened shape withouta tail. The robotic fish is composed of a body and two lateral fins. A three-factor kinematic model is established and used in thedesign of a mechanism. By controlling the three kinematic parameters, the robotic fish can accelerate and maneuver. Forwardvelocity is dependent on the largest amplitude and the number of waves in the fins, while the relative contribution of fin beatfrequency to the forward velocity of the robotic fish is different from the usual result. On the other hand, experimental results onmaneuvering show that phase difference has a stronger effect on swerving than the largest amplitude to some extent. In addition,as propulsion waves pass from the trailing edge to the leading edge, the robotic fish attains a backward velocity of 0. 15 m·s<sup>-1</sup>.
