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31.
分别从预算编制、预算执行、预算考评以及财务预测等方面探讨了提高企业财务预算管理系统柔性的方法,提出了在实行刚性预算管理的同时,也要实行柔性预算管理的观点。 相似文献
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James C. A. Peacock Kevin Ball 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(6):608-621
In football, kicking with high ball velocity can increase scoring opportunities and reduce the likelihood of interception. Efficient energy transfer from foot to ball during impact is important to attain a high ball velocity. It is considered impact efficiency can be increased by reducing the change in ankle plantarflexion during foot–ball impact. However, conflicting evidence exists, questioning its effectiveness as a coaching cue. The aim of the present study was to systematically analyse joint stiffness, foot velocity and impact location with a mechanical kicking machine to determine if change in ankle plantarflexion during foot–ball impact and ball velocity are influenced. Sagittal plane data of the shank, foot and ball were measured using high-speed video (4,000 Hz). Increasing joint stiffness reduced change in ankle plantarflexion and increased ball velocity from a greater effective mass. Increasing foot velocity increased change in ankle plantarflexion and increased ball velocity. Distal impact locations increased change in ankle plantarflexion and reduced ball velocity as coefficient of restitution decreased. These results identify that change in ankle plantarflexion is a dependent variable during foot–ball impact and does not directly influence ball velocity. Coaches can assess ankle motion during impact to provide feedback to athletes on their impact efficiency. 相似文献
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以改善非台阶孔车刀加工性能为研究对象,对传统通孔粗车刀几何形状进行了改进。改进后的内孔车刀具有减小切削力、切削温度相对降低、减少切削振动与噪音等特点。 相似文献
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简要分析了AEA在水泥砼的应用中对改善砼早期收缩,提高砼的耐久性的作用机理。提出防水砼无缝设计的依据以及实际施工中的具体操作要点。 相似文献
35.
Wenchuan earthquake damage survey displayed the major structures of buildings suffered only small damages, but it was common that infill walls suffered heavy damages or even collapse. To study the failure forms and collapse mechanism of infill walls in an earthquake, the influence of opening or length-to-height ratio on shake-resisting capability of filling walls was analyzed, and measures to improve the anti-collapse ability of infill walls were put forwaed. The numerical simulations on collapse process in earthquake were carried out by using ABAQUS software. We used 5 single story and single span models. It is revealed that the rigidity and compressive capacity of infill walls are reduced because of the infill walls with holes and the increases of length-to-height ratios. Adding constructional columns and horizontal beams can ensure structural integrity and imp rove the anti-collap se ability of the wall. 相似文献
36.
韩宝卫 《天津职业院校联合学报》2009,11(2)
机械零件的加工必须要保证零件达到图样的要求,满足其加工精度。而尺寸精度、形位精度和表面粗糙度是检验零件加工精度最主要的三个方面。三者任何一项达不到要求都会造成零件质量的下降或报废等问题。其中形状和位置精度可以通过设备、夹具、刀具、工艺等来加以保证,而尺寸精度和表面粗糙度的控制则是难点。 相似文献
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Cooperative system bridges comprise several basic structures that act jointly to improve structural characteristics. We delved into the historical development of cooperative system bridges. Cooperative systems are classified as different-load cooperative systems and same-load cooperative systems by distinguishing the modes of load distribution. For different-load cooperation, individual basic structures are at different positions in the direction along bridge axis and carry the loads separately. While for same-load cooperation, all basic structures overlap in geometrical locations and support the entire loads conjointly. The choosing of span ratios between basic structures, the design of connections of different-load cooperative systems were discussed as well as optimizations of relative rigidity for same-load cooperative systems which greatly influence structural characteristics. The general situation and several structural measurements of several cooperative bridges were demonstrated. This information can assist engineers in developing their concepts in cooperative systems and can lead to more efficient and economical cooperative bridges. 相似文献
39.
复双曲空间中的全纯曲线 总被引：1，自引：0，他引：1
研究复双曲空间中的全纯曲线。给出了这种全纯曲线的Frenet公式，运用Frenet公式给出一些已知结果的简洁证明。 相似文献
40.
污水资源化是我国当前的紧要任务。采用经济有效、符合中国国情的污水回用技术是实现污水资源化的最佳途径，而不应一味追求用高科技产品来实现。能高效服务于生产实际的才是最好的。 相似文献