Study on mechanical principle of reinforcing sidewalls and corners of roadway to control floor heave by anchors

The movement principle of sidewalls and floor of extraction opening is analyzed, it is found that floor heave not only has something to do with the floor strata, but sidewalls. The effect of sidewall anchor and corner anchor is studied, the mechanical principle of reinforcing sidewalls and corners is put forward and applied in engineering practice.     

Modeling dynamic developable meshes by the Hamilton principle

In this paper, a new dynamic developable surface model is proposed. The proposed model represents developable surfaces using triangle meshes. A novel algorithm is proposed to introduce the Hamilton principle into these meshes such that the resulting developable model is dynamic, i.e., it can offer a time-dependent continuous path to deform the model. Applications with examples are presented; these show that the proposed technique can model buckled developable surfaces well, and can offer physically-realistic animations of deformed developable surfaces.     

Nonpathological Lyapunov functions and discontinuous Carathéodory systems

Differential equations with discontinuous right-hand side and solutions intended in Carathéodory sense are considered. For these equations, sufficient conditions which guarantee both Lyapunov stability and asymptotic stability in terms of nonsmooth Lyapunov functions are given. An invariance principle is also proven.     

电控柴油机的原理及应用前景

电控柴油机以其节能、环保、易于控制等特点。获得了广泛的应用。为了更好地了解该项新产品，使其尽早在石油机械上推广使用。提升中国石油机械的品质，文章对电控柴油机的特点、结构及应用前景进行了讨论。     

Al2O3对唐钢高炉炉渣性能的影响

针对唐钢近2年提高进口矿配比后，Al2O3含量升高对炉渣流动性带来的不利影响，对唐钢高炉的炉渣性能进行了试验研究。并结合国内同行业的生产实践经验，从理论上分析了炉渣中Al2O3及MgO的适宜含量范围，着重论述了唐钢所处冀东矿区条件下降低Al2O3的主要途径及适应高Al2O3炉渣的具体措施。     

新型二合一液压锚定器的研制

作业起泵过程中常常伴随大量原油、污水落地。目前，各大油田使用的投棒式泄油器成功率较低。为了简化作业管柱．提高工作效率．研制了新型锚定器．并通过计算，确定了该锚定器关键部件的技术参数。经过142井次的使用，证明该二合一液压锚定器既能泄油．减少原油、污水污染．又能锚定管柱，提高泵效，减少检泵周期。     

浅谈SSFC桥梁伸缩装置的原理及施工

从结构组成及工作原理、技术特点及优势等方面简述了SSFC伸缩装置，并对其安装工艺及关键质量控制点和维修及保养进行了阐述，以推广SSFC伸缩装置的应用。     

接地电阻对地电场观测的影响及克服方法

论述了测量电极的接地电阻对振幅和相位测量精度的影响规律，提出了克服接地电阻影响，提高野外观测精度的切实可行的方法和技术。     

Design of noise and period-time robust high-order repetitive control, with application to optical storage

Repetitive control is useful if periodic disturbances or setpoints act on a control system. Perfect (asymptotic) disturbance rejection is achieved if the period time is exactly known. The improved disturbance rejection at the periodic frequency and its harmonics is achieved at the expense of a degraded system sensitivity at intermediate frequencies. A convex optimization problem is defined for the design of high-order repetitive controllers, where a trade-off can be made between robustness for changes in the period time and for reduction of the error spectrum in-between the harmonic frequencies. The high-order repetitive control algorithms are successfully applied in experiments with the tracking control of a CD-player system.     

便携式多功能找星仪

找星仪是卫星地面站安装、调试、维修所必不可少的设备。旧的找星仪笨重、由于必须两人操作,很不方便。针对这些问题开发了便携式多功能找星仪。本文主要介绍了该设备的构成及其电路原理。