无支护立井井筒极限深度的上限解答

本文应用极限分析的上限方法,对库仑材料立井井筒的稳定性进行研究,对于内摩擦角φ=20°的情况,通过进行非线性优化,给出了井筒极限深度的上限解答,并对不同材料参数时的机动场进行了讨论。     

解决数据一维平衡的数组变换遍历算法

本文提出了解决数据一维平衡的一个新的算法—数组变换遍历算法，给出了该算法的数学基础、方法步骤、程序描述及算法分析。     

拱坝多目标优化设计

本文解决了在优化中考虑稳定约束、开挖量、开挖深度、拉应力区等问题,并根据本文的数学模型编制了FORTRAN77程序在长城0520A型微机(与IBM—PC兼容)上实现,经过实际工程优化设计的考验,证明了本文程序的实用价值,为拱坝优化设计的全面推广创造了条件。     

新型焦利氏秤

介绍新型焦利氏秤的结构特点及其工作原理,并举例说明其用法。     

白沙灌区水量平衡试验站的试验装置与观测资料初步分析

本文简要地叙述了建立白沙站的目的意义、任务、观测项目内客和要求,以及水量平衡场的设计、施工的主要特点.着重对17个重砂壤土测筒的不同水位埋深与潜水蒸发量关系(包括无作物与有作物)等不同处理的观测资料数据作了分析.初步找出了一规些律,并建立了数学模式.     

运用经济数学原理浅议聚丙烯生产的损益

本文运用损益平衡原理，分析了聚丙烯生产经营状况，制定未来营销决策．     

弹性连杆机构震动力最小化构件截面参数综合

本文将“最佳性准则法”应用于弹性连杆机构运动弹性动力综合,提出了在应力约束下通过修正构件截面参数,实现机构震动力最小化的一种新方法,并给出了计算实例。     

Characterization of Kovar-to-Kovar laser welded joints and its mechanical strength

For the packaging of a pump laser in butterfly package, the most crucial assembly step is the fiber-to-laser diode coupling and attachment. The use of laser welding as the joining method offers several advantages if compared with the adhesive joints: strong joining strength, short process time and less contamination. This paper reports on laser welding process characteristics; weld strength and its fracture mode. The penetration depth and melt area of laser spot welds were found to be complicated functions of laser pulse energy, intensity, and beam diameter. Effects of pulse width, input power and size of the focal spot on the rate of energy input to the workpieces and consequently, the weld strength were reported. The weld strength was found to be dependent on the overlapping area between the two joining materials. Surface roughness, R_a, has influence on the fraction of energy absorbed, A, and therefore, affecting the penetration depth. Thermal analysis was carried out on the laser-welded joints and its heat-affected zone (HAZ) induced by various power densities was examined. These data are important in order to optimize and utilize the laser welding process as an effective manufacturing tool for fabrication of reliable pump laser.     

基于多源LBS数据的职住平衡对比研究 ——以北京城区为例

采用多源LBS数据(热力图数据、POI数据、微博签到数据), 对北京城区职住关系进行测定和分析, 从不同角度测度北京城区职住关系的时间和空间特征, 研究结果可为改善城市职住关系提供决策参考。比较了LBS数据同传统人口和经济普查数据所测度的职住关系结果的差异性, 讨论差异产生原因, 为更好地利用LBS数据进行职住关系研究提供建议。     

A Design of Extreme Long Focal Depth Binary Optical Element

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