基于模型试验,采用1978年国际拖曳水池会议(International Towing Tank Conference,ITTC)推荐的实船功率、航速预报方法对船舶在静水中的主机功率和航速进行预报。采用ITTC推荐的阻力、推力一致法对船舶在风浪环境中的功率进行预报,其中...基于模型试验,采用1978年国际拖曳水池会议(International Towing Tank Conference,ITTC)推荐的实船功率、航速预报方法对船舶在静水中的主机功率和航速进行预报。采用ITTC推荐的阻力、推力一致法对船舶在风浪环境中的功率进行预报,其中,风阻采用经验公式计算,波浪增阻采用基于切片法的辐射能法和近似公式计算。在此基础上,结合主机的燃油特性,对船舶在风浪中的主机油耗进行预报。分析风速、波高和浪向对主机油耗的影响,结果表明:在艏斜浪范围内,浪向对油耗的影响不明显;随着波高的升高和风速的增大,相同转速下船舶的航速减小,单位里程的油耗增加。展开更多
In order to predict the speed loss in the actual sea states more precisely, delivered power shall be measured more accurately as an input. Therefore, based on a 50,000 DWT tanker, various results obtained from differe...In order to predict the speed loss in the actual sea states more precisely, delivered power shall be measured more accurately as an input. Therefore, based on a 50,000 DWT tanker, various results obtained from different prediction methods were compared by a series of model tests performed in calm water and in waves. It is shown that speed loss deprived from RTIM （resistance and thrust identity method） method in regular waves test could satisfy the engineering requirements most.展开更多
General Fission(GEF)模型是描述裂变过程的一种半经验模型,它运用了量子力学和统计力学中的物理概念,并结合经验信息调整出了一组适用于不同裂变系统的参数,可以对大量原子核的裂变可观测量给出可靠的预测.本工作使用GEF模型计算了233...General Fission(GEF)模型是描述裂变过程的一种半经验模型,它运用了量子力学和统计力学中的物理概念,并结合经验信息调整出了一组适用于不同裂变系统的参数,可以对大量原子核的裂变可观测量给出可靠的预测.本工作使用GEF模型计算了233U中子诱发裂变产额的质量分布.结果表明,随着入射中子能量增加,对称裂变贡献逐渐增大,非对称裂变贡献逐渐减小;考虑了多次机会裂变,(n,f)裂变道相对贡献随着入射中子能量增加逐渐降低,而其他裂变道贡献增加;裂变产物的产额能量变化趋势与其在质量分布上的不同位置有关.展开更多
This paper is a short revisit to Kuo-Brown effective interaction derived from the Hamada-Johnston nucleon-nucleon potential, done by Gerry Brown and Tom Kuo. This effective interaction, derived in year 1966, is the fi...This paper is a short revisit to Kuo-Brown effective interaction derived from the Hamada-Johnston nucleon-nucleon potential, done by Gerry Brown and Tom Kuo. This effective interaction, derived in year 1966, is the first attempt to describe nuclear structure properties from the free nucleon-nucleon potential. Nowadays much progress has been achieved for the effective interactions in shell model. We would compare the effective interactions obtained in the 1966 paper with up-to-date shell-model interactions in sd-shell and pf-shell model space. Recent knowledge of effective interactions on nuclear structure, can also be traced in the KuoBrown effective interaction, i.e., the universal roles of central and tensor forces, which reminds us that such discovery should be noticed much earlier.展开更多
Understanding the properties of nuclei inside "island of inversion" is still an interesting issue. Based on a simple Nilsson model with a new set of isospin-dependent parameters, and with non-axial deformati...Understanding the properties of nuclei inside "island of inversion" is still an interesting issue. Based on a simple Nilsson model with a new set of isospin-dependent parameters, and with non-axial deformations considered, we have performed three-dimensional potential-energy-surface calculations for Ne, Na, Mg and Al isotopes that are claimed to be in or nearby the A～30 island of inversion". It is found that shape coexistence and triaxial deformation(or softness) exist in these nuclei. Large deformations are obtained by the improved Nilsson parameters, which explains the observed large electric quadrupole transition probabilities. The large deformations happening in30 Ne,31Na,32 Mg and33Al indicate the quenching of the spherical N = 20 neutron shell gap. The calculations of nuclear binding and two-neutron separation energies have been also improved with the isospin-dependent parameters and the inclusion of the non-axial deformation degree of freedom.展开更多
文摘基于模型试验,采用1978年国际拖曳水池会议(International Towing Tank Conference,ITTC)推荐的实船功率、航速预报方法对船舶在静水中的主机功率和航速进行预报。采用ITTC推荐的阻力、推力一致法对船舶在风浪环境中的功率进行预报,其中,风阻采用经验公式计算,波浪增阻采用基于切片法的辐射能法和近似公式计算。在此基础上,结合主机的燃油特性,对船舶在风浪中的主机油耗进行预报。分析风速、波高和浪向对主机油耗的影响,结果表明:在艏斜浪范围内,浪向对油耗的影响不明显;随着波高的升高和风速的增大,相同转速下船舶的航速减小,单位里程的油耗增加。
文摘In order to predict the speed loss in the actual sea states more precisely, delivered power shall be measured more accurately as an input. Therefore, based on a 50,000 DWT tanker, various results obtained from different prediction methods were compared by a series of model tests performed in calm water and in waves. It is shown that speed loss deprived from RTIM （resistance and thrust identity method） method in regular waves test could satisfy the engineering requirements most.
基金National Natural Science Foundation of China(11505035,11465005,11505056,11605054,11675266,U1732138,11775057,11765004,11565008)Natural Science Foundation of Guangxi,China(2017GXNSFAA198160,2015GXNSFDA139004)Project of Innovative Team and Distinguished Scholar in Institutions of Higher Education of Guangxi,China~~
基金supported by the National Natural Science Foundation of China(Grant Nos.11275067 and 11447109)the support from the Helmholtz Association(HGF)through the Nuclear Astrophysics Virtual Institute(VH-VI-417)
文摘This paper is a short revisit to Kuo-Brown effective interaction derived from the Hamada-Johnston nucleon-nucleon potential, done by Gerry Brown and Tom Kuo. This effective interaction, derived in year 1966, is the first attempt to describe nuclear structure properties from the free nucleon-nucleon potential. Nowadays much progress has been achieved for the effective interactions in shell model. We would compare the effective interactions obtained in the 1966 paper with up-to-date shell-model interactions in sd-shell and pf-shell model space. Recent knowledge of effective interactions on nuclear structure, can also be traced in the KuoBrown effective interaction, i.e., the universal roles of central and tensor forces, which reminds us that such discovery should be noticed much earlier.
基金supported by the National Natural Science Foundation of China(Grants Nos.11275067,11447109 and 11505056)
文摘Understanding the properties of nuclei inside "island of inversion" is still an interesting issue. Based on a simple Nilsson model with a new set of isospin-dependent parameters, and with non-axial deformations considered, we have performed three-dimensional potential-energy-surface calculations for Ne, Na, Mg and Al isotopes that are claimed to be in or nearby the A～30 island of inversion". It is found that shape coexistence and triaxial deformation(or softness) exist in these nuclei. Large deformations are obtained by the improved Nilsson parameters, which explains the observed large electric quadrupole transition probabilities. The large deformations happening in30 Ne,31Na,32 Mg and33Al indicate the quenching of the spherical N = 20 neutron shell gap. The calculations of nuclear binding and two-neutron separation energies have been also improved with the isospin-dependent parameters and the inclusion of the non-axial deformation degree of freedom.
