基于对象关系的物料清单管理技术研究

针对物料清单的特点提出了一个基于对象模型和关系实现的管理方法。为物料清单建立一个面向对象的模型，采用特定的对象关系映射策略，将对象的物料清单映射到关系数据库中，既可以达到用面向对象的方法来描述和建立物料清单的目的，又可以采用成熟的关系数据库方法来存储和管理物料清单数据。     

H∞ filtering for a class of discrete-time singular Markovian jump systems with time-varying delays

The problem of _H∞$H_{\infty }$ filtering for a class of discrete-time singular Markovian jump systems with time-varying delays is investigated in this paper. The transition probabilities under consideration are time-varying, i.e., Markovian chain is nonhomogeneous. By using the Lyapunov functional approach and reciprocally convex technique, a less conservative delay-dependent bounded real lemma is developed in terms of linear matrix inequalities. Moreover, a sufficient condition for the existence of the desired filter which guarantees the stochastic admissibility and the _H∞$H_{\infty }$ performance index of the resulting filtering error system is presented. Numerical examples are employed to show the usefulness of the proposed results.     

试论切削液的发展方向

回顾了金属切削的工艺过程。切削液的主要作用是冷却和润滑，其效果反映在刀具的使用寿命上。影响刀具寿命的主要因素，是切削刀具的表面温度。水基切削液以其导热系数大、成本低，得到长足发展。由于环保要求日益严格，水基切削液的使用费由原来占生产费1％上升到12％～17％，水基切削液的价格优势不复存在。根据国内外的实验研究，切削油中加入极压剂，切削表面的摩擦下降60％～80％；加氢基础油黏度低、闪点高、蒸发损失少，为油基切削液低粘化创造了必要条件。油基切削液的研究和发展有广阔前景。     

逆向工程中基于能量法的参数二阶连续曲面构造方法研究

针对反求过程中的单值曲面重构问题,提出一种基于能量法的曲面构造方法,给出了关于能量模型建立和边界条件处理的详细理论推导。提出的截面线构造方法、平面四边形域中间参数线自动生成、跨界导矢插值公式均可用作通用方法。随后以汽车前面板曲面构造为例说明了方法有效性和其他特点。     

金刚石砂轮电解修整磨削液的防锈性能研究

分析几种防锈添加剂对金属结合剂金刚石砂轮电解修整磨削液防锈性能的影M向，通过试验确定了几种防锈添加剂的合理含量，以及不同氯化钠电解液浓度所对应的各类添加剂含量。论文确定了金刚石砂轮电解修整磨削液的基本组成，并进行了电解修整磨削液的电解性能试验。     

改进PSO优化ELM预测锂离子电池剩余寿命

针对极限学习机在预测锂离子电池剩余寿命过程中的不稳定性,提出利用混合粒子群优化算法对极限学习机预测模型优化的方法。通过改进的粒子群优化算法对极限学习机的输入端进行寻优处理,不但能够使模型的预测精度有进一步提高,而且大大增加了锂离子电池单次剩余寿命预测结果的可信度。利用NASA PCoE公开的锂离子电池数据进行仿真实验并评估该模型的预测性能,然后与标准的极限学习机预测模型预测结果进行对比,统计结果表明该方法使预测误差控制在2%左右。     

SCUFFING MODEL CONSIDERING INFLUEN OF HYDRODYNAMIC LUBRICATION

ＳＣＵＦＦＩＮＧＭＯＤＥＬＣＯＮＳＩＤＥＲＩＮＧＩＮＦＬＵＥＮＣＥＯＦＨＹＤＲＯＤＹＮＡＭＩＣＬＵＢＲＩＣＡＴＩＯＮＳＣＵＦＦＩＮＧＭＯＤＥＬＣＯＮＳＩＤＥＲＩＮＧＩＮＦＬＵＥＮＣＥＯＦＨＹＤＲＯＤＹＮＡＭＩＣＬＵＢＲＩＣＡＴＩＯＮＹａｎｇＷｅｎｔｏ...     

Improvement in wear resistance of plasma sprayed yttria stabilized zirconia coating using nanostructured powder

Plasma sprayed yttria stabilized zirconia coatings were prepared using nanostructured and conventional powders with optimized process parameters for the highest deposition efficiency, the smallest porosity and the highest microhardness. The tribological properties of these coatings against 100C6 steel were then tested with a ball-on-disc arrangement. Results showed that although the friction coefficients of the coatings sprayed using the nanostructured powder were slightly different from those of the coatings sprayed using the conventional powder, the former coatings were more wear resistant than the latter coatings. The wear mechanisms of all the coatings were explained in terms of adhesion-induced spallation and micro-fracturing of lamellae. The improvement in wear resistance of the coatings sprayed using the nanostructured powder could be mainly ascribed to the decrease of micrometer-sized defects such as pores and interlamellar and intralamellar cracks in the coatings.     

Wirtinger-based multiple integral inequality for stability of time-delay systems

Note that the conservatism of the delay-dependent stability criteria can be reduced by increasing the integral terms in Lyapunov–Krasovskii functional (LKF). This brief revisits the stability problem for a class of linear time-delay systems via multiple integral approach. The novelty of this brief lies in that a Wirtinger-based multiple integral inequality is employed to estimate the derivative of a class of LKF with multiple integral terms. Based on these innovations, a new delay-dependent stability criterion is derived in terms of linear matrix inequalities. Two numerical examples are exploited to demonstrate the effectiveness and superiority of the proposed method.