The prosperous post buckling load capacity of web plates of box girders can be used.In this article,the post buckling behaviour of web plates of box girders under different loading conditions is theoretically analyz...The prosperous post buckling load capacity of web plates of box girders can be used.In this article,the post buckling behaviour of web plates of box girders under different loading conditions is theoretically analyzed and on the basis of domestic and overseas design codes of steel structures,the corresponding simplified analysis methods are put forward for the engineering design or code revision.It is proved that the simplified methods are safe,efficient and practicable through the comparison between several results.展开更多
When the frigate moves forward,due to the ship motion such as pitching and rolling,the flow over the flight deck becomes very complex,which may seriously threaten the taking off and landing of the ship-borne helicopte...When the frigate moves forward,due to the ship motion such as pitching and rolling,the flow over the flight deck becomes very complex,which may seriously threaten the taking off and landing of the ship-borne helicopter.The flow fields over the different modified simple frigate shape(SFS)models,consisting of the hangar and flight deck,were numerically studied by changing the ratio of hangar height and length in the static state and pitching state.For different models,the contours of velocity and pressure above the flight deck,as well as the variations of velocity components of the observation points and line in static state and pitching state were compared and analyzed.The results show that the size of recirculation zone and the location of the reattachment point have distinct differences for diverse models,and reveal the tracks of recirculation zone’s center and reattachment position in a pitching period.In addition,the velocity components at two observation positions also change periodically with the periodic motion.Furthermore,the deviations of the velocity components in static state and pitching state are relatively large,therefore,the flow fields in static state cannot be used to simulate that in pitching state correctly.展开更多
Some rules of simplification of area feature boundary and the method of acquiring spatial knowledge, such as maintaining area and shape of area feature, are discussed. This paper focuses on the progressive method of g...Some rules of simplification of area feature boundary and the method of acquiring spatial knowledge, such as maintaining area and shape of area feature, are discussed. This paper focuses on the progressive method of graphic simplification of area feature boundary with right angles based on its characteristics.展开更多
The Double Folding （DF） model calculation of the internuclear potential in heavy-ion interactions when the participant nuclei are deformed in their ground states involves a six-dimensional integral. Using the multip...The Double Folding （DF） model calculation of the internuclear potential in heavy-ion interactions when the participant nuclei are deformed in their ground states involves a six-dimensional integral. Using the multipole expansion in these calculations, the DF six-dimensional integral reduce to the sum of the products of three single-dimensional integrals. In this paper we have presented a procedure for the calculation of the radius dependent functions in the multipole expansion of the nuclear density and their Fourier transforms. We have also reduced the DF model integrals to the sum of the single dimensional integrals using the obtained relations for the radius dependent functions in the multipole expansion and their Fourier transforms.展开更多
I systematize thoughts within the scope of J6zef Ba6ka＇s philosophical system known as recentivism. I analyze the axiology of recentivism in two categories： recens （i.e., ＂now＂） and pure-mindedness. Also, I diff...I systematize thoughts within the scope of J6zef Ba6ka＇s philosophical system known as recentivism. I analyze the axiology of recentivism in two categories： recens （i.e., ＂now＂） and pure-mindedness. Also, I differentiate among pure-mindedness, which is a quality of homo euthyphronicus （i.e., pure-minded man）, simplicity, which is a quality of homo simplex （i.e., simple man）, and complexity, which is a quality of homo technicus （i.e., technical man）. Moreover, I present different meanings of pure-mindedness which form the basis for reflection in the axiology of recentivism, i.e., the ethics of pure-mindedness, euthyphronics, and esthetics. Then, I use these meanings of pure-mindedness to define the attitude of homo euthyphronicus. Homo euthyphronicus is a man who seeks balance between simplicity and complexity in the modem world, which is highly complex and full of civilization-related threats, while stressing the importance of axioiogical values.展开更多
As a hyper-redundant robot, a 3D snake-like robot can perform many other configurations and types of locomotion adapted to environment except for mimicking the natural snake locomotion. The natural snake locomotion us...As a hyper-redundant robot, a 3D snake-like robot can perform many other configurations and types of locomotion adapted to environment except for mimicking the natural snake locomotion. The natural snake locomotion usually limits locomotion capability of the robot because of inadequacy in the mechanism and actuation to imitate characters of natural snake such as the too many DOFs and the characteristics of the muscle. In order to apply snake-like robots to the unstructured environment, the researchers have designed many gaits for increasing the adaptability to a variety of surroundings. The twist-related locomotion is an effective gait achieved by jointly driving the pitching-DOF and yawing-DOF, with which the snakelike robot can move on rough ground and even climb up some obstacles. In dfis paper, the twist-related locomotion function is firstly solved, and simplified to be expressible by sine or cosine function. The 2D locomotion such as V-shape and U-shape is achieved. Also by applying it to the serpentine locomotion or other types of locomotion, the snake-like robot can complete composite locomotion that combines the serpentine locomotion or others with twist-related locomotion. Then we extend the twist-related locomotion to 3D space. Finally, the experimental results are presented to validate all above analyses.展开更多
Pile-anchor retaining structure is widely used in foundation pit engineering and side slope engineering in many countries. In contrast to strut, pile-anchor retaining structure has its typical features and advantages....Pile-anchor retaining structure is widely used in foundation pit engineering and side slope engineering in many countries. In contrast to strut, pile-anchor retaining structure has its typical features and advantages. It does not occupy the internal space of the foundation pit, and the project cost is much lower. Accurate prediction of the lateral displacement of the retaining structure is very important in the design stage. A simplified analysis method and several calculation assumptions of the lateral deformation of pile-anchor retaining structures are set up according to the engineering features. The expression function of lateral displacement versus depth is solved by means of a fitted function and the quasi-elastic summation method. The parameters are obtained through the stiffness equation of the anchors and the principle of minimum potential energy. The analytical evaluation of the lateral deformation curve is then completed, whose applicability is proved through practical engineering.展开更多
基金Supported by Ministry of Metallurgical Industry of China
文摘The prosperous post buckling load capacity of web plates of box girders can be used.In this article,the post buckling behaviour of web plates of box girders under different loading conditions is theoretically analyzed and on the basis of domestic and overseas design codes of steel structures,the corresponding simplified analysis methods are put forward for the engineering design or code revision.It is proved that the simplified methods are safe,efficient and practicable through the comparison between several results.
基金supported by the Fundamental Research Funds for the Central Universities(No. NS2019006)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘When the frigate moves forward,due to the ship motion such as pitching and rolling,the flow over the flight deck becomes very complex,which may seriously threaten the taking off and landing of the ship-borne helicopter.The flow fields over the different modified simple frigate shape(SFS)models,consisting of the hangar and flight deck,were numerically studied by changing the ratio of hangar height and length in the static state and pitching state.For different models,the contours of velocity and pressure above the flight deck,as well as the variations of velocity components of the observation points and line in static state and pitching state were compared and analyzed.The results show that the size of recirculation zone and the location of the reattachment point have distinct differences for diverse models,and reveal the tracks of recirculation zone’s center and reattachment position in a pitching period.In addition,the velocity components at two observation positions also change periodically with the periodic motion.Furthermore,the deviations of the velocity components in static state and pitching state are relatively large,therefore,the flow fields in static state cannot be used to simulate that in pitching state correctly.
文摘Some rules of simplification of area feature boundary and the method of acquiring spatial knowledge, such as maintaining area and shape of area feature, are discussed. This paper focuses on the progressive method of graphic simplification of area feature boundary with right angles based on its characteristics.
文摘The Double Folding （DF） model calculation of the internuclear potential in heavy-ion interactions when the participant nuclei are deformed in their ground states involves a six-dimensional integral. Using the multipole expansion in these calculations, the DF six-dimensional integral reduce to the sum of the products of three single-dimensional integrals. In this paper we have presented a procedure for the calculation of the radius dependent functions in the multipole expansion of the nuclear density and their Fourier transforms. We have also reduced the DF model integrals to the sum of the single dimensional integrals using the obtained relations for the radius dependent functions in the multipole expansion and their Fourier transforms.
文摘I systematize thoughts within the scope of J6zef Ba6ka＇s philosophical system known as recentivism. I analyze the axiology of recentivism in two categories： recens （i.e., ＂now＂） and pure-mindedness. Also, I differentiate among pure-mindedness, which is a quality of homo euthyphronicus （i.e., pure-minded man）, simplicity, which is a quality of homo simplex （i.e., simple man）, and complexity, which is a quality of homo technicus （i.e., technical man）. Moreover, I present different meanings of pure-mindedness which form the basis for reflection in the axiology of recentivism, i.e., the ethics of pure-mindedness, euthyphronics, and esthetics. Then, I use these meanings of pure-mindedness to define the attitude of homo euthyphronicus. Homo euthyphronicus is a man who seeks balance between simplicity and complexity in the modem world, which is highly complex and full of civilization-related threats, while stressing the importance of axioiogical values.
文摘As a hyper-redundant robot, a 3D snake-like robot can perform many other configurations and types of locomotion adapted to environment except for mimicking the natural snake locomotion. The natural snake locomotion usually limits locomotion capability of the robot because of inadequacy in the mechanism and actuation to imitate characters of natural snake such as the too many DOFs and the characteristics of the muscle. In order to apply snake-like robots to the unstructured environment, the researchers have designed many gaits for increasing the adaptability to a variety of surroundings. The twist-related locomotion is an effective gait achieved by jointly driving the pitching-DOF and yawing-DOF, with which the snakelike robot can move on rough ground and even climb up some obstacles. In dfis paper, the twist-related locomotion function is firstly solved, and simplified to be expressible by sine or cosine function. The 2D locomotion such as V-shape and U-shape is achieved. Also by applying it to the serpentine locomotion or other types of locomotion, the snake-like robot can complete composite locomotion that combines the serpentine locomotion or others with twist-related locomotion. Then we extend the twist-related locomotion to 3D space. Finally, the experimental results are presented to validate all above analyses.
基金the National Natural Science Foundation of China (No. 51178267)the Science and Technology Committee of Shanghai (No. 10231200600)
文摘Pile-anchor retaining structure is widely used in foundation pit engineering and side slope engineering in many countries. In contrast to strut, pile-anchor retaining structure has its typical features and advantages. It does not occupy the internal space of the foundation pit, and the project cost is much lower. Accurate prediction of the lateral displacement of the retaining structure is very important in the design stage. A simplified analysis method and several calculation assumptions of the lateral deformation of pile-anchor retaining structures are set up according to the engineering features. The expression function of lateral displacement versus depth is solved by means of a fitted function and the quasi-elastic summation method. The parameters are obtained through the stiffness equation of the anchors and the principle of minimum potential energy. The analytical evaluation of the lateral deformation curve is then completed, whose applicability is proved through practical engineering.
