The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate...The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate with each other to complete a search and rescue task.Secondly,a threat assessment method based on meteorological data was proposed,and potential meteorological threats,such as storms and rainfall,can be predicted by collecting and analyzing meteorological data.Finally,an experiment was carried out to evaluate the performance of the proposed method in different scenarios.The experimental results show that the coordinated search and rescue system of unmanned/manned aircraft can be used to effectively assess meteorological threats and provide accurate search and rescue guidance.展开更多
This study explores the significance,current research landscape,and conceptualization of sports safety promotion.Safety in sports is fundamental to youth physical activities,and an excessive focus on or neglect of saf...This study explores the significance,current research landscape,and conceptualization of sports safety promotion.Safety in sports is fundamental to youth physical activities,and an excessive focus on or neglect of safety is unwarranted.Globally,numerous countries have extensively researched sports safety promotion and implemented diverse strategies.Drawing from KABP(Knowledge,Attitude,Behavior,Practice)theory and 4M(Man,Machine,Medium,Management)management,this paper presents a conceptual framework for sports safety promotion.It integrates these theories to devise a comprehensive accident prevention model within a sports safety promotion system.The framework prioritizes enhancing students’safety literacy and underscores the practical application of safety knowledge and skills in simulated sports settings following structured safety education.It aims to enhance students’competency and proficiency in averting sports-related injuries.展开更多
On the basis of the characteristics of ancient Chinese culture,the paper discusses the formation inevitability of the 'Coexistence between Heaven and Man' building concept,the connection and the differences wi...On the basis of the characteristics of ancient Chinese culture,the paper discusses the formation inevitability of the 'Coexistence between Heaven and Man' building concept,the connection and the differences with the ecological concept of modern Chinese Vernacular Architecture.The key point is that the contemporary design should absorb the ancient Chinese culture of the 'Coexistence between Heaven and Man' building concept and the essence of Chinese Vernacular Architecture ecological concept,forming the design features of local ecology based on the environmental protection and harmonious coexistence.展开更多
In light of increasingly worsening environmental pollution,this paper,through comparing different attitudes towards the relationship between man and nature in Chinese and the western culture,points out rebuilding a ha...In light of increasingly worsening environmental pollution,this paper,through comparing different attitudes towards the relationship between man and nature in Chinese and the western culture,points out rebuilding a harmonious relationship between man and nature is the common object of human being,and appeals to people to shake off man-centered thinking pattern,and to treat nature as our friend.展开更多
Ralph Ellison’s Invisible Man deals with the identity issue fundamental for black Americans to reestablish themselves in the white-dominated society.While the narrator suffers from identity crisis in multiples ways,t...Ralph Ellison’s Invisible Man deals with the identity issue fundamental for black Americans to reestablish themselves in the white-dominated society.While the narrator suffers from identity crisis in multiples ways,the paper focuses on the conflict between his need to build a distinctive individual identity with the prerequisite to surrender to collective identity in order to blend in the group.展开更多
Spermiogenesis is a complex process leading to the formation of motile spermatozoa characterized by a highly stable chromatin compaction that transfers the paternal genome into the oocyte. It is commonly held that the...Spermiogenesis is a complex process leading to the formation of motile spermatozoa characterized by a highly stable chromatin compaction that transfers the paternal genome into the oocyte. It is commonly held that these haploid cells are devoid of transcriptional and translational activities and that the transcripts represent remnants of stored mRNAs. Recently, the chromatin organization of mature spermatozoa has been revisited as a double nucleoprotamine-nucleohistone structure possessing less-condensed regions sensitive to nuclease activity, which could be implicated in the expression of genes involved in the early embryo development. The existence of a complex population of mRNAs in human sperm is well-documented, but their role is not yet elucidated. Evidence for a latent transcriptional capacity and/or a potential de novo translation in mature spermatozoa from fertile men are essential for understanding the last steps of sperm maturation, such as capacitation and acrosome reaction. As such, we have documented the relationship between sperm quality and the distribution of sperm RNAs by showing divergent levels of transcripts encoding for proteins involved in either nuclear condensation (protamines 1 and 2) or in capacitation (eNOS and nNOS, c-myc) or in motility and sperm survival (aromatase) between low and high motile sperm issued from the same sample. Therefore, analyzing the profile of mRNAs could be helpful either as a diagnostic tool for evaluating male fertility after spermatogenesis or for prognosis use for fertilization.展开更多
Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a su...Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.展开更多
Manned combat aerial vehicles (MCAVs), and un-manned combat aerial vehicles (UCAVs) together form a cooper-ative engagement system to carry out operational mission, whichwill be a new air engagement style in the n...Manned combat aerial vehicles (MCAVs), and un-manned combat aerial vehicles (UCAVs) together form a cooper-ative engagement system to carry out operational mission, whichwill be a new air engagement style in the near future. On the basisof analyzing the structure of the MCAV/UCAV cooperative engage-ment system, this paper divides the unique system into three hi-erarchical levels, respectively, i.e., mission level, task-cluster leveland task level. To solve the formation and adjustment problem ofthe latter two levels, three corresponding mathematical modelsare established. To solve these models, three algorithms calledquantum artificial bee colony (QABC) algorithm, greedy strategy(GS) and two-stage greedy strategy (TSGS) are proposed. Finally,a series of simulation experiments are designed to verify the effec-tiveness and superiority of the proposed algorithms.展开更多
China's 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench...China's 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench from the depth of 5500 to 6700 m, to investigate the geological, biological and chemical characteristics in the hadal area. During the cruise, JIAOLONG deployed a gas-tight serial sampler to collect the water near the sea bottom regularly. Five days later, the sub located the sampler in another dive and retrieved it successfully from the same location, which is the first time that scientists and engineers finished the high accuracy in-situ deployment and retrieval using a manned submersible with Ultra-Short Base Line (USBL) positioning system at the depth more than 6600 m. In this task, we used not only the USBL system of the manned submersible but also a compound strategy, including five position marks, the sea floor terrain, the depth contour, and the heading of the sub. This paper introduces the compound strategy of the target deployment and retrieval with the practical diving experience of JIAOLONG, and provides a promising technique for other underwater vehicles such as manned submersible or Remote Operated Vehicle (ROV) under similar conditions.展开更多
A deep-sea Manned Submarine Vehicle (MSV) is usually required to move at a low forward speed and a low rotational speed when it executes investigation tasks. In this condition, the motion is in large drift angles, a...A deep-sea Manned Submarine Vehicle (MSV) is usually required to move at a low forward speed and a low rotational speed when it executes investigation tasks. In this condition, the motion is in large drift angles, and the maneuverability hydrodynamic forces cannot be expressed properly in the conventional mathematical model of submersible motion. In this paper, firstly, a general equation of MSV with six-freedom motion is presented, and the numerical simulation of descent/ascent motion and helix motion is conducted to reveal the general maneuver characteristics of MSV. Secondly, according to the data of captive model tests of large drift angles of MSV, the regression analysis of position hydrodynamic forces and rotation hydrodynamic forces is carried out, and the results of regression analysis of maneuverability hydrody- namic characteristics are analyzed to reveal the special maneuver characteristics. Thirdly, a special new mathematical model of MSV with the whole range of drift angles motion is presented, which can be used to predict hydrodynamic performance of motion in the 0° - 180° range of drift angles. The results are applied to the design of maneuverability hydrodynamic forces, development of control system and simulator of a practical MSV.展开更多
This study investigates the interaction and influence of surface cracks on the spherical pressure hull of a deep-sea manned submersible.The finite element model of the spherical hull is established,and a semi-elliptic...This study investigates the interaction and influence of surface cracks on the spherical pressure hull of a deep-sea manned submersible.The finite element model of the spherical hull is established,and a semi-elliptical surface crack is inserted in the welding toe of the spherical hull as the main crack.Considering the combined effect of external uniform pressure and welding residual stress at the weld toe,the stress intensity factor(SIF)is obtained based on the M-integral method.Inserting disturbing cracks at different positions on the spherical hull surface,the interaction and influence between multi-cracks are revealed by numerical calculation.The results show that the existence of the disturbing crack has a great influence on the stress intensity factor of the main crack,and the influence is different with the different location of disturbing crack.The study of the interaction of multiple cracks under different interference factors and the influence of disturbing cracks on the main crack can provide some reference for future engineering applications.展开更多
The Old Man and the Sea tells a tough and frustrated experience of an old fisherman.The theme is a praise of heroism.The enlightenment of the work is that "man is not made for defeat...[a] man can be destroyed bu...The Old Man and the Sea tells a tough and frustrated experience of an old fisherman.The theme is a praise of heroism.The enlightenment of the work is that "man is not made for defeat...[a] man can be destroyed but not defeated."展开更多
With the rapid development of ocean technology, the deep-sea manned submersible is regarded as a high-tech equipment for the exploration and exploitation of ocean resources. The safety of manned cabin has a decisive e...With the rapid development of ocean technology, the deep-sea manned submersible is regarded as a high-tech equipment for the exploration and exploitation of ocean resources. The safety of manned cabin has a decisive effect on the whole system. Ti-6 Al-4 V with the superior strength-to-weight ratio and corrosion resistance has been used for the manned cabin. The manned cabin experiences loading spectrum with different maximum stresses and different dwell time during their service life. The load sequence effects on dwell fatigue crack growth behavior of Ti-6 Al-4 V under different dwell time are investigated experimentally in this paper. The experimental results show that the crack tip plastic zone is enlarged by the dwell time and the overload retardation zone increases with dwell time under the same overload rate. A dwell fatigue crack growth model is proposed by modifying the crack tip plastic zone under the loading history with combinations of the single overload and dwell time factors are included in the modified model. Based on the experimental data, the overload retardation zone and the crack growth rates of Ti-6 Al-4 V are predicted by the modified model. A reasonable model for the load sequence effect on the dwell fatigue crack growth rates of Ti-6 Al-4 V is verified.展开更多
The Dirac equation for Eckart potential and trigonometric Manning Rosen potential with exact spin symmetry is obtained using an asymptotic iteration method. The combination of the two potentials is substituted into th...The Dirac equation for Eckart potential and trigonometric Manning Rosen potential with exact spin symmetry is obtained using an asymptotic iteration method. The combination of the two potentials is substituted into the Dirac equation, then the variables are separated into radial and angular parts. The Dirac equation is solved by using an asymptotic iteration method that can reduce the second order differential equation into a differential equation with substitution variables of hypergeometry type. The relativistic energy is calculated using Matlab 2011. This study is limited to the case of spin symmetry. With the asymptotic iteration method, the energy spectra of the relativistic equations and equations of orbital quantum number l can be obtained, where both are interrelated between quantum numbers. The energy spectrum is also numerically solved using the Matlab software, where the increase in the radial quantum number nr causes the energy to decrease. The radial part and the angular part of the wave function are defined as hypergeometry functions and visualized with Matlab 2011. The results show that the disturbance of a combination of the Eckart potential and trigonometric Manning Rosen potential can change the radial part and the angular part of the wave function.展开更多
Ernest Hemingway, a famous American writer, is considered as one of tbe most impor-tant and Outstanding wriers of the 20th century in the world. This essay is to deal mainly with tbe writ-ing techniques OfThe Old Man ...Ernest Hemingway, a famous American writer, is considered as one of tbe most impor-tant and Outstanding wriers of the 20th century in the world. This essay is to deal mainly with tbe writ-ing techniques OfThe Old Man And the Sea as well as the character about the main hero, aiming to helpthe readers get a better understanding of the masterpiece by Hemingway-展开更多
基金the Study on the Impact of the Construction and Development of Southwest Plateau Airport on the Ecological Environment(CZKY2023032).
文摘The architecture and working principle of coordinated search and rescue system of unmanned/manned aircraft,which is composed of manned/unmanned aircraft and manned aircraft,were first introduced,and they can cooperate with each other to complete a search and rescue task.Secondly,a threat assessment method based on meteorological data was proposed,and potential meteorological threats,such as storms and rainfall,can be predicted by collecting and analyzing meteorological data.Finally,an experiment was carried out to evaluate the performance of the proposed method in different scenarios.The experimental results show that the coordinated search and rescue system of unmanned/manned aircraft can be used to effectively assess meteorological threats and provide accurate search and rescue guidance.
文摘This study explores the significance,current research landscape,and conceptualization of sports safety promotion.Safety in sports is fundamental to youth physical activities,and an excessive focus on or neglect of safety is unwarranted.Globally,numerous countries have extensively researched sports safety promotion and implemented diverse strategies.Drawing from KABP(Knowledge,Attitude,Behavior,Practice)theory and 4M(Man,Machine,Medium,Management)management,this paper presents a conceptual framework for sports safety promotion.It integrates these theories to devise a comprehensive accident prevention model within a sports safety promotion system.The framework prioritizes enhancing students’safety literacy and underscores the practical application of safety knowledge and skills in simulated sports settings following structured safety education.It aims to enhance students’competency and proficiency in averting sports-related injuries.
文摘On the basis of the characteristics of ancient Chinese culture,the paper discusses the formation inevitability of the 'Coexistence between Heaven and Man' building concept,the connection and the differences with the ecological concept of modern Chinese Vernacular Architecture.The key point is that the contemporary design should absorb the ancient Chinese culture of the 'Coexistence between Heaven and Man' building concept and the essence of Chinese Vernacular Architecture ecological concept,forming the design features of local ecology based on the environmental protection and harmonious coexistence.
文摘In light of increasingly worsening environmental pollution,this paper,through comparing different attitudes towards the relationship between man and nature in Chinese and the western culture,points out rebuilding a harmonious relationship between man and nature is the common object of human being,and appeals to people to shake off man-centered thinking pattern,and to treat nature as our friend.
文摘Ralph Ellison’s Invisible Man deals with the identity issue fundamental for black Americans to reestablish themselves in the white-dominated society.While the narrator suffers from identity crisis in multiples ways,the paper focuses on the conflict between his need to build a distinctive individual identity with the prerequisite to surrender to collective identity in order to blend in the group.
文摘Spermiogenesis is a complex process leading to the formation of motile spermatozoa characterized by a highly stable chromatin compaction that transfers the paternal genome into the oocyte. It is commonly held that these haploid cells are devoid of transcriptional and translational activities and that the transcripts represent remnants of stored mRNAs. Recently, the chromatin organization of mature spermatozoa has been revisited as a double nucleoprotamine-nucleohistone structure possessing less-condensed regions sensitive to nuclease activity, which could be implicated in the expression of genes involved in the early embryo development. The existence of a complex population of mRNAs in human sperm is well-documented, but their role is not yet elucidated. Evidence for a latent transcriptional capacity and/or a potential de novo translation in mature spermatozoa from fertile men are essential for understanding the last steps of sperm maturation, such as capacitation and acrosome reaction. As such, we have documented the relationship between sperm quality and the distribution of sperm RNAs by showing divergent levels of transcripts encoding for proteins involved in either nuclear condensation (protamines 1 and 2) or in capacitation (eNOS and nNOS, c-myc) or in motility and sperm survival (aromatase) between low and high motile sperm issued from the same sample. Therefore, analyzing the profile of mRNAs could be helpful either as a diagnostic tool for evaluating male fertility after spermatogenesis or for prognosis use for fertilization.
基金Supported by the "863" Foundation under Grant No.2002AA401000
文摘Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.
基金supported by the National Natural Science Foundation of China(61573017)the Doctoral Innovation Found of Air Force Engineering University(KGD08101604)
文摘Manned combat aerial vehicles (MCAVs), and un-manned combat aerial vehicles (UCAVs) together form a cooper-ative engagement system to carry out operational mission, whichwill be a new air engagement style in the near future. On the basisof analyzing the structure of the MCAV/UCAV cooperative engage-ment system, this paper divides the unique system into three hi-erarchical levels, respectively, i.e., mission level, task-cluster leveland task level. To solve the formation and adjustment problem ofthe latter two levels, three corresponding mathematical modelsare established. To solve these models, three algorithms calledquantum artificial bee colony (QABC) algorithm, greedy strategy(GS) and two-stage greedy strategy (TSGS) are proposed. Finally,a series of simulation experiments are designed to verify the effec-tiveness and superiority of the proposed algorithms.
基金financially supported the National Natural Science Foundation of China(Grant No.61703118)the National Key Research and Development Program of China(Grant No.2016YFB0501703)+1 种基金Taishan Scholars Climbing Program of Shandong(Grant No.TSPD20161007)International Marine Resources Investigation and Development Program of China Ocean Mineral Resources R&D Association and the Strategic Precursor Program of Chinese Academy of Sciences
文摘China's 7000 m manned submersible JIAOLONG carried out an exploration cruise at the Mariana Trench from June to July 2016. The submersible completed nine manned dives on the north and south area of the Mariana Trench from the depth of 5500 to 6700 m, to investigate the geological, biological and chemical characteristics in the hadal area. During the cruise, JIAOLONG deployed a gas-tight serial sampler to collect the water near the sea bottom regularly. Five days later, the sub located the sampler in another dive and retrieved it successfully from the same location, which is the first time that scientists and engineers finished the high accuracy in-situ deployment and retrieval using a manned submersible with Ultra-Short Base Line (USBL) positioning system at the depth more than 6600 m. In this task, we used not only the USBL system of the manned submersible but also a compound strategy, including five position marks, the sea floor terrain, the depth contour, and the heading of the sub. This paper introduces the compound strategy of the target deployment and retrieval with the practical diving experience of JIAOLONG, and provides a promising technique for other underwater vehicles such as manned submersible or Remote Operated Vehicle (ROV) under similar conditions.
基金supported by the National High Technology Research and Development Program of China(863 Program, Grant No.2002AA401002)
文摘A deep-sea Manned Submarine Vehicle (MSV) is usually required to move at a low forward speed and a low rotational speed when it executes investigation tasks. In this condition, the motion is in large drift angles, and the maneuverability hydrodynamic forces cannot be expressed properly in the conventional mathematical model of submersible motion. In this paper, firstly, a general equation of MSV with six-freedom motion is presented, and the numerical simulation of descent/ascent motion and helix motion is conducted to reveal the general maneuver characteristics of MSV. Secondly, according to the data of captive model tests of large drift angles of MSV, the regression analysis of position hydrodynamic forces and rotation hydrodynamic forces is carried out, and the results of regression analysis of maneuverability hydrody- namic characteristics are analyzed to reveal the special maneuver characteristics. Thirdly, a special new mathematical model of MSV with the whole range of drift angles motion is presented, which can be used to predict hydrodynamic performance of motion in the 0° - 180° range of drift angles. The results are applied to the design of maneuverability hydrodynamic forces, development of control system and simulator of a practical MSV.
基金This work was supported by the State Key Program of National Natural Science of China(Grant No.51439004)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(Grant No.19KJA530002)the Open Project Foundation of State Key Laboratory of Ocean Engineering(No.2006).
文摘This study investigates the interaction and influence of surface cracks on the spherical pressure hull of a deep-sea manned submersible.The finite element model of the spherical hull is established,and a semi-elliptical surface crack is inserted in the welding toe of the spherical hull as the main crack.Considering the combined effect of external uniform pressure and welding residual stress at the weld toe,the stress intensity factor(SIF)is obtained based on the M-integral method.Inserting disturbing cracks at different positions on the spherical hull surface,the interaction and influence between multi-cracks are revealed by numerical calculation.The results show that the existence of the disturbing crack has a great influence on the stress intensity factor of the main crack,and the influence is different with the different location of disturbing crack.The study of the interaction of multiple cracks under different interference factors and the influence of disturbing cracks on the main crack can provide some reference for future engineering applications.
文摘The Old Man and the Sea tells a tough and frustrated experience of an old fisherman.The theme is a praise of heroism.The enlightenment of the work is that "man is not made for defeat...[a] man can be destroyed but not defeated."
基金financially supported by the National Natural Science Foundation of China (Grant No. 51709134)the National Key R&D Program of China (Grant No. 2016YFC0300603-02)the Natural Science Foundation of Jiangsu Province (Grant Nos. BK20160559 and BK20170575)。
文摘With the rapid development of ocean technology, the deep-sea manned submersible is regarded as a high-tech equipment for the exploration and exploitation of ocean resources. The safety of manned cabin has a decisive effect on the whole system. Ti-6 Al-4 V with the superior strength-to-weight ratio and corrosion resistance has been used for the manned cabin. The manned cabin experiences loading spectrum with different maximum stresses and different dwell time during their service life. The load sequence effects on dwell fatigue crack growth behavior of Ti-6 Al-4 V under different dwell time are investigated experimentally in this paper. The experimental results show that the crack tip plastic zone is enlarged by the dwell time and the overload retardation zone increases with dwell time under the same overload rate. A dwell fatigue crack growth model is proposed by modifying the crack tip plastic zone under the loading history with combinations of the single overload and dwell time factors are included in the modified model. Based on the experimental data, the overload retardation zone and the crack growth rates of Ti-6 Al-4 V are predicted by the modified model. A reasonable model for the load sequence effect on the dwell fatigue crack growth rates of Ti-6 Al-4 V is verified.
基金supported by the Higher Education Project(Grant No.698/UN27.11/PN/2015)
文摘The Dirac equation for Eckart potential and trigonometric Manning Rosen potential with exact spin symmetry is obtained using an asymptotic iteration method. The combination of the two potentials is substituted into the Dirac equation, then the variables are separated into radial and angular parts. The Dirac equation is solved by using an asymptotic iteration method that can reduce the second order differential equation into a differential equation with substitution variables of hypergeometry type. The relativistic energy is calculated using Matlab 2011. This study is limited to the case of spin symmetry. With the asymptotic iteration method, the energy spectra of the relativistic equations and equations of orbital quantum number l can be obtained, where both are interrelated between quantum numbers. The energy spectrum is also numerically solved using the Matlab software, where the increase in the radial quantum number nr causes the energy to decrease. The radial part and the angular part of the wave function are defined as hypergeometry functions and visualized with Matlab 2011. The results show that the disturbance of a combination of the Eckart potential and trigonometric Manning Rosen potential can change the radial part and the angular part of the wave function.
文摘Ernest Hemingway, a famous American writer, is considered as one of tbe most impor-tant and Outstanding wriers of the 20th century in the world. This essay is to deal mainly with tbe writ-ing techniques OfThe Old Man And the Sea as well as the character about the main hero, aiming to helpthe readers get a better understanding of the masterpiece by Hemingway-