双曲余弦柔性铰链转动刚度及其参数关系的研究

柔性铰链以其独特的性能在微动机器人领域有着广泛的应用,而刚度是柔性铰链的最主要性能之一。以力学公式和微积分为基础,推导出了双曲余弦柔性铰链的转动刚度及其系数表达式。应用matlab软件编程计算得出柔性铰链的转动刚度与其自身各结构参数的关系。     

旋转摩擦挤压法制备Al-Mg合金的组织和力学性能

采用旋转摩擦挤压法(RFE)制备了不同Mg含量的Al-Mg铝合金,对其进行力学性能测试和显微组织观察.结果表明:退火态的5A06基材经RFE加工后,晶粒明显细化,抗拉强度和伸长率同时提高.采用5A06和AZ31B为基材经RFE加工制备Al-Mg合金后,合金抗拉强度随Mg含量的增加而增加,但伸长率却随合金Mg含量的增加而...     

The dynamic viscosity of liquid Cu–Si alloys

The dynamic viscosity of liquid Cu–Si alloys is measured in the Cu-rich composition range (up to 40 at.% Si). The Arrhenius-law describing the temperature dependence of the viscosity holds for all alloys investigated. The viscosity isotherms, both experimental and from thermodynamic model calculations, show a broad maximum covering the homogenity ranges of the intermetallic phases. An interconnection of such findings with the atomic structure of the liquid alloys is briefly discussed.     

An experimental validation of a specific energy-based approach for comminution

In a recent paper [Khumalo, N., Glasser, D., Hildebrandt, D., Hausberger, B., Kauchali, S., 2006. The application of the attainable region analysis to comminution. Chemical Engineering Science 61, 5969-5980] it was shown that the attainable region approach could prove useful in designing better comminution circuits. Fundamental to this approach was the assumption that the rate of comminution was only determined by the specific energy within the device. This paper shows experimentally that this assumption holds for a batch ball mill.The system presented here considered breakage of mono-sized feed particles in a laboratory ball mill into two distinct progeny size classes. The population balance model was successfully used to model the experimental products and the results were represented geometrically in a two-dimensional space. The resulting geometric structure can be used to solve process synthesis and optimization problems simultaneously.It was found that the breakage rate parameter out of size class 1 changes with time but exhibits an exponential relationship with an asymptote. It is hypothesized that this asymptote is the rate of breakage at long grind times or in well-mixed, steady-state continuous systems. It is shown that the parameters of the process depend only on the specific energy. This was one of the assumptions that was made in the construction of the attainable region. Thus, equipment selection and operating conditions only require one to match the required specific energy.     

直齿锥齿轮摆线旋分加工数学模型及参数优化

针对直齿锥齿轮加工方法间歇分度、生产效率低的问题，基于直齿锥齿轮摆线旋分加工方法，采用空间曲线逼近直线的数学方法解释直齿锥齿轮旋分加工原理。在此基础之上，给出摆线旋分加工数学模型，即切削点轨迹的数学模型，并分析影响参数，确定各参数范围及影响规律，进而获得符合加工要求的切削点轨迹。     

手持式FFT分析仪及其在涡轮增压器转速测量中的应用

以８０Ｃ１９６为核心的手持式ＦＦＴ分析仪，对复数范围内１０２４点进行浮点快速傅里叶变换，从而得到被测信号的频谱图，通过分析处理频谱图的特征，诊断出被测对象的工作状态。同时，将共进行微型化设计，并应用于对机车涡轮增压转速的间接测量，无需拆装外壳，取得了良好的效果。     

Automatic rotational symmetry determination for shape analysis

The determination of the rotational symmetry of a shape is useful for object recognition and shape analysis in computer vision applications. In this paper, a simple, but effective, algorithm to analyse the rotational symmetry of a given closed-curve shape S is proposed. A circle C with the centroid of S as the circle center and the average radius of S as the circle radius is superimposed on S, resulting in the intersection of C and S at a set of points. By theoretical analysis, the relationship between the order N_s of the rotational symmetry of S and the number of intersection points between C and S is established. All the possible values for N_s are determined. And finally N_s is determined by evaluating the similarity between S and its rotated versions. In the proposed algorithm, only simple pixel operations and second-order moment function computation are involved. Several problems caused by the use of discrete image coordinates are analysed and solved for correct decision-making in the algorithm. Good experimental results are also included.     

爆破膜装置在水电站的应用

主要阐述了作为水电站调节保证措施的爆破膜装置的原理、性能和工作参数的计算。对于具有较长的有压引水系统的水电站、需要增容扩建的水电站，这一装置具有一定的推广应用价值。本装置也可以应用于输水管道抽水站及引水工程。     

Making rotational invariance of particle swarm optimization based on correlativity

In this letter, we point out that particle swarm optimization (PSO) lacks rotational invariance through an analysis using numerical experiments. After the analysis based on rotational invariance, we develop PSO with rotational invariance based on correlativity. The performance of the proposed PSO with rotational invariance is verified through numerical experiments for typical separable benchmark functions without and with rotation.     

气压及转速对高速压力机下死点的影响

通过使用下死点检测仪,对某型号高速压力机进行下死点波形测试,揭示了无负载时静平衡气压与曲柄转速发生变化时的下死点变化规律.分析了产生这种规律的原因,建立了曲线方程并对方程的显著性进行了检验,提出了提高下死点精度的改进措施.