A new dynamical mechanism of incomplete fusion in heavy-ion collision
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Abstract:
The incomplete fusion has been proved as the formation and emission of the $α$ particle by the increase in the rotational energy of the very mass-asymmetric dinuclear system. The results of the dinuclear system model have confirmed that the incomplete fusion in heavy-ion collisions occurs at a large orbital angular momentum ($L > 30 \hbar$) due to the strong increase of the intrinsic fusion barrier.Keywords:
Fusion mechanism
Particle (ecology)
For more improvement of the collision safety, it is necessary that not only collision safety evaluation and measure at the primary collision, which is the accident between the vehicles at the first collision, but also collision safety evaluation at the secondary collision, which is another accident occurred by subsequence collision. However, collision experiment and safety measure, which is considered to secondary collision, are not sufficiently carried out, since the vehicle motion after the first collision is complicated and difficult to predict, although theoretical analysis has been reported. In this study, in order to evaluate the influence factors for collided vehicle motion after collision, we carried out the collision experiment at the difference of collision position with vehicle model, and compare the experimental results at the each collision position. As the results, the difference of collision position affects vehicle rotation and moving distance.
Collision attack
Position (finance)
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Author had proposed in his previous paper a model for estimating the probabilities of collision of ships at waterways applying the queuing theory to the relation between collision avoiding maneuvers and marine traffic. The improved model of collision avoiding system in the present paper was represented by two parameters named the intensity and the allowance of collision avoiding maneuvers, of which the practical meanings of ship handling were discussed. The model was applied to the ships navigating through the ten narrow channels in Japan in order to study the feasibility of the model. The probabilities of collision of ships at each channel by the model were compared with their statistical rates of collision there in last five years and their agreements were found to be good except the low values of the probabilities of collision. Based on the model, the situations of collision and the factors which had influences on collision were quantitatively investigated. It would be capable by the model for us to evaluate the effects of traffic controls and endeavors of navigators to prevent collision on the probabilities of collision.
Allowance (engineering)
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A new design of anti-collision device is present in this paper. When the collision occurs, with the deformation movement, the anti-collision device can transfer the collision energy to the non-contact area, store the energy and release after collision, which can not only protect the protected object, but also reduce the damage to the collision-causing object, ensuring the anti-collision device itself can be reusable. As a result, this design of anti-collision device can greatly reduce damages and economic losses caused by the accidental collision.
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Fusion power
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Abstract The consequences of ship collision could be very serious, causing lots of human casualties, environmental pollution and huge economic losses. It is essential to study the collision process including two ships in water. In the past, most ship collision tests are based on the study of collision damage of local structures and there are few experiments considering the motion response of ships during the collision process. Actually, the interaction between the fluid and structure does have effects on the collision consequences. In this paper, the collision experiments of ship models are conducted in a water tank, with particular attention on structure in the collision region. Considering the coupling effect of external dynamics and internal mechanics, the dynamic responses of ships during collision are studied. The failure mode and deformation damage characteristics of ship’s side structure in collision region are also assessed. On this basis, the time history of collision forces, the damage extent of the struck structure and the energy absorption are analyzed and then the influence of velocity and ship’s mass on the results are evaluated. It provides valuable test data for validation of numerical simulation and theoretical studies.
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Superheavy Elements
Fusion mechanism
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The safety of ships in regards to collisions and groundings, as well as the navigational and structural aspects of ships, has been improved and developed up to this day by technical, administrative and nautical parties. The damage resulting from collisions could be reduced through several techniques such as designing appropriate hull structures, ensuring tightness of cargo tanks as well as observation and review on structural behaviors, whilst accounting for all involved parameters. The position during a collision can be influenced by the collisions' location and angle as these parts are included in the external dynamics of ship collisions. In this paper, the results of several collision analyses using the finite element method were used and reviewed regarding the effect of location and angle on energy characteristic. Firstly, the capabilities of the structure and its ability to resist destruction in a collision process were presented and comparisons were made to other collision cases. Three types of collisions were identified based on the relative location of contact points to each other. From the results, it was found that the estimation of internal energy by the damaged ships differed in range from 12%–24%. In the second stage, the results showed that a collision between 30 to 60 degrees produced higher level energy than a collision in the perpendicular position. Furthermore, it was concluded that striking and struck objects in collision contributed to energy and damage shape.
Position (finance)
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Pauli exclusion principle
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Collision simulation of river-sea ship is accomplished based on nonlinear finite element method. Firstly, we discuss the development of collision analysis methods including theoretical methods, empirical formula method, experimental techniques and numerical analysis methods, and introduce the Central Difference Method adopted in the collision simulation. Then, model of ship structure and rigid sphere structure are established, through taking into account the suitability for collision simulation of ship structure, we adopt Cowper-Symonds constitutive equation as the material characteristics and maximum equivalent plasticity as the failure criterion. Finally, collision-resistant performance of riversea ship is simulated through collisions between ship structure and rigid sphere structure at cargo centre and cargo end. Simulation results indicate that damage extent of river-sea ship depends on collision speed primarily, with the increase of collision speed, collision force increases accordingly, local structure invalidates and local damage occurs. Comparison between collision at cargo centre and collision at cargo end shows that the improvement of structural rigidity is effective to increase collision-resistant performance. Such, it is necessary to make evaluation on collision-resistant performance and strengthen the structures easily collided for ship designed according to specification, especially for the ship with single side structure. The research is of great guiding significance to hull structure design, and it is beneficial to increase security of the same type ship.
Rigidity (electromagnetism)
Response amplitude operator
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