基于停滞检测的双向搜索灰狼优化算法

针对灰狼优化算法（GWO）易陷入局部最优、收敛速度低的问题,提出了一种基于停滞检测的双向搜索灰狼优化算法（DBGWO）。为了提升初始种群的质量,引入了Bernouilli shift映射;为了充分利用GWO特有的头狼机制,实现整体提升算法性能的目的,提出一种双向搜索策略;为了提升算法跳出局部最优的能力、增加算法的收敛速度,提出一种停滞检测机制,针对算法是否有陷入局部最优风险的判断,狼群会采取相应的措施改变当前状态。通过对23个基准测试函数进行仿真实验结果表明,所提算法在求解多峰函数问题上效果显著,同时在求解最优解非0点的函数问题上表现也较为优越。将该算法用于求解多阈值图像分割问题,解决了用Kapur熵法计算多阈值时耗时过长的问题。     

Bioconvective Casson nanofluid flow toward stagnation point in non-Darcy porous medium with buoyancy effects,chemical reaction,and thermal radiation

The emphasis on non-Newtonian fluid encountered in biomedical, pharmaceuticals, mining, food, chemical, and plastics industries and in noticeably enormous diverse industrial applications influenced this article. This study is accomplished in a non-Darcy porous stretching surface to investigate the stagnation point of bioconvective Casson nanofluid. Chemical reaction, applied consistent magnetic field, radiative heat transfer, and buoyancy force consequences are studied for numerical examination. Composed of nonlinear partial differential equations for the above presumptions and reforming them into ordinary differential equations by means of compatible transformations are enforced. Adopting the fifth order Runge–Kutta Felhberg method with the shooting technique obtained a numerical solution. Obtained solutions are authenticated by comparing previous solutions. The major finding includes the reduction of the Casson parameter on the skin friction coefficient.     

集装箱卸料平台的应用与实践

随着贵冶铜产量不断提升,各种地方矿、集装箱进口矿的用量也在不断增加。因卸车能力受限,入厂的集装箱进口矿和地方矿不能同时卸车,从而出现滞箱现象。为满足集装箱进口矿和地方矿卸车要求,在现备料二系统精矿库2#仓区域,增设专门用于集装箱进口矿的卸料平台,并在3#精矿库东侧新建雨棚,满足雨天卸料作业要求。     

Research on arc root stagnation when small current is interrupted in self-excited circuit breaker

The self-excited DC air circuit breaker (SE-DCCB) has been widely used in urban rail transit due to its excellent stability. It can realize forward and reverse interruption, but has difficulty interrupting small currents due to the phenomenon of arc root sticking at the entrance of the arc chamber in the splitting process, which is known as arc root stagnation. A coupling model of the self-excited magnetic field and magnetohydrodynamics is established for the SE-DCCB with the traditional structure. The magnetic field, temperature and airflow distribution in the arc chamber are investigated with an interrupting current of 150 A. The simulation results show that the direction and magnitude of the magnetic blowout force are the dominant factors in the arc root stagnation. The local high temperature of the arc chamber due to arc root stagnation increases the obstruction effect of the airflow vortex on the arc root movement, which significantly increases the arc duration time of small current interruption. Based on the research, the structure of the magnetic conductance plate of the actual product is improved, which can improve the direction and magnitude of the magnetic blowout force at the arc root so as to restrain the development of the airflow vortex effectively and solve the problem of arc root stagnation when the small current is interrupted. The simulation results show that the circuit breaker with improved structure has a better performance for a small current interruption range from 100 A to 350 A.