Forbidden transition probabilities of astrophysical interest among low-lying states of V III

Electric and magnetic multipole transitions among low-lying states of doubly ionized vanadium were computed using the multi-configuration Hartree-Fock (MCHF) method with Breit-Pauli (BP) corrections to a non-relativistic Hamiltonian. Energy levels were determined up to and including 3d ²(¹ G)4s b ² G _7/2 and computed energies were found to be in good agreement with experiment and other theories. In addition to Einstein A _ki coefficients for some E2 and M1 transitions, lifetime data and selected weighted oscillator strengths are also reported.     

非均匀流中立管涡激振动模型预测分析

文中分析了非均匀流中,张紧式海洋立管的涡激振动,采用新的加速度耦合尾流振子模型作为预测细长海洋工程柔性结构的计算工具,将预测结果中的横向位移包络线及最大幅值与实验观测值、shear7软件计算值进行了对比,可以发现模型的计算结果与实验观测结果吻合得很好.     

调相白噪声背景中高稳频率源参数估计

调相白噪声背景中高稳频率源参数的估计是一个应用广泛的信号处理问题 ,给出了利用平方拟合估计频率源参数的方法 ,它是最小平方误差意义下的估计 ,并根据模拟的数据对这种方法作了验证。     

Dynamic simulation of beam-like structure with a crack subjected to a random moving mass oscillator

In this paper,dynamic simulation of a beam-like structure with a transverse open crack subjected to a random moving mass oscillator is investigated.The simultaneous effect of a crack and a random oscillator has not been addressed up to now.The crack in the beam at different locations and with different depths is considered as one group of damage,each as an individual imperfection.In addition,bearing immobility is considered as another type of problem in the beam.Mass, stiffness,damping and velocity of th...     

全套管旋挖钻进技术及其应用

介绍了全套管旋挖钻进技术应用范围,并论述了几种不同形式的旋挖全套管钻进用设备及工法、套管的结构性能以及其相应的施工工艺。     

基于谐振子遗传算法的高效地下水优化管理模型

在传统遗传算法和模拟谐振子算法的基础上,结合两者的优点,提出了一种新型快速高效的谐振子遗传算法。通过一个理想的水资源管理模型的算例和一个华北平原典型区地下水资源优化的实际算例,从寻优结果和寻优效率两个方面对谐振子遗传算法、传统遗传算法和模拟谐振子算法进行了对比分析。在两个地下水管理模型中,与传统的遗传算法和模拟谐振子算法相比,新型的谐振子遗传算法搜索效率达到模拟谐振子算法搜索效率的2倍以上,得到的最优解比遗传算法所得到的最优解分别增加供水量1.1×10³ m³/d和0.47×10⁸ m³/a,说明谐振子遗传算法具有更强的全局搜索能力和更好的寻优效率。     

涪陵页岩气田钻井提速方案及实施效果分析

在深入分析涪陵页岩气田制约钻井速度的因素的基础上,针对性地提出了钻井提速的方案,并进行了大量的现场应用。本文详细介绍了国民油井旋冲工具、水力振荡器、POB抗油基泥浆螺杆钻具的组成和技术原理。阐述了以上3种工具在涪陵区块的应用效果和优势,并提出了使用中存在的不足和应改进的技术问题。这些工具的实施效果表明,国民油井提出的钻井提速方案是切实可行的,对该区域后期优快水平井钻井工艺的选择具有指导意义。     

用于检测同相轴的Duffing型系统恢复力项的讨论

在用于检测同相轴的Duffing型系统中,非线性恢复力项的选取至关重要.针对具有不同非线性恢复力项的混沌系统,本文首先就非线性恢复力项的来源进行了说明,通过对哈密顿系统和耗散系统的仿真实验分析,以及理论推导,确定了势能—哈密顿多项式方程中可用于混沌振子检测系统的各项幂次和各项系数组合关系,即非线性恢复力项的选取规则:幂次最高项为奇次,其系数大于零.     

Dissipative travelling wave solution for El Niño tropic sea-air coupled oscillator

El Niño and Southern Oscillation (ENSO) is an interannual phenomenon involved in the tropical Pacific sea-air interactions. An asymptotic method of solving equations for the ENSO model is proposed. Based on a class of oscillator of ENSO model and by employing a simple and valid method of the variational iteration, the coupled system for a sea-air oscillator model of interdecadal climate fluctuations is studied. Firstly, by introducing a set of functionals and computing the variationals, the Lagrange multipliers are obtained. And then, the generalized variational iteration expressions are constructed. Finally, by selecting appropriate initial iteration, and from the iterations expressions, the approximations of solution for the sea-air oscillator ENSO model are solved successively. The approximate dissipative travelling wave solution of equations for corresponding ENSO model is studied. It is proved from the results that the method of the variational iteration can be used for analyzing the sea surface temperature anomaly in the equatorial Pacific of the sea-air oscillator for ENSO model.     

On the MgH oscillator strengths

The theoretical estimates of the oscillator strengths by Kirby, Saxon and Liu (1979) for theA II₂ — XΣ² system of the MgH molecule are compared with the solar photospheric results. It is found that the two results are in reasonable agreement.