节能轴支架的作用原理设计方法和叶剖面优化

介绍了节能轴支架的作用机理、设计方法和叶剖面的优化。节能轴支架的作用机理与桨前固定导轮相似 ,但设计要比桨前固定导轮简化 ,并要兼顾轴支架自身的作用和要求。文中详细给出了轴支架的布置形式和在船模试验中获得的显著节能效果。试验结果证明把轴支架的两支臂设计成有约 1 0°的收缩角可增大节能轴支架的预旋作用 ,从而增大节能效果 ,使轴支架的节能效果达约 1 2 %。空泡试验和激振力测量结果表明 ,把Eppler的翼型势流设计方法设计翼型与解 N-S方程进行流场分析相结合 ,用层流型高升阻比翼型优化节能轴支架是成功的 ,能有效地降低轴支架的阻力和推迟空泡初生 ,从而有利于节能轴支架在高速船上推广应用。实船安装证明本文的设计方法是成功的     

The choice of speed and clearance for RAS on 3D method

In this paper, a 3D source distribution technique is used to calculate the coupled motions between two ships which advance in the wave with the same speed. The numerical results of coupled motions for a frigate and a supply ship have a good agreement with the experimental results. Based on the 3D coupled motions of two ships, a spectral analysis is employed to clearly observe the effect of speed, clearance and wave heading on the significant relative motion amplitude (SRMA) of two ships.The method presented in this paper will be helpful to select suitable clearance, speed and wave heading for underway replenishment at sea(RAS).     

Examining the influence of multidestination service orientation on transit service productivity: a multivariate analysis

Between 1990 and 2000, U.S. transit agencies added service and increased ridership, but the ridership increase failed to keep pace with the service increase. The result was a decline in service effectiveness (or productivity). This marks the continuation of a long-running and often-studied trend. The scholarly literature attributes this phenomenon, at least in part, to transit agency decisions to decentralize their service rather than focus on serving the traditional CBD market. Many scholars argue that a decentralized service orientation is both ineffective and inefficient because it attracts few riders and requires large per-rider subsidies. This research tests whether a non-traditional, decentralized service orientation, called multidestination service, results in reduced service productivity. Contrary to what the literature suggests, we find that MSAs whose transit agencies pursued a multidestination service orientation did not experience lower productivity. These results indicate that policies that have encouraged the growth of decentralized transit services have not necessarily been detrimental to the industry.

A total generalized optimal velocity model and its numerical tests

A car-following model named total generalized optimal velocity model （TGOVM） was developed with a consideration of an arbitrary number of preceding vehicles before current one based on analyzing the previous models such as optimal velocity model （OVM）, generalized OVM （GOVM） and improved GOVM （IGOVM）. This model describes the physical phenomena of traffic flow more exactly and realistically than previous models. Also the performance of this model was checked out by simulating the acceleration and deceleration process for a small delay time. On a single circular lane, the evolution of the traffic congestion was studied for a different number of headways and relative velocities of the preceding vehicles being taken into account. The simulation results show that TGOVM is reasonable and correct.     

浅谈当代大学生审美价值取向

当代大学生在思想、道德、精神文化等方面的价值体系发生了许多分化与重组,在审美层面的集中体现为由统一转向多样、由教化主导转向自由选择．     

磁通门罗盘的数字信号处理方法

为提高磁通门罗盘的指向精度和稳定性,提出了磁通门罗盘的数字信号处理方法。利用微处理器直接产生激励信号,通过模数转换采集磁通门传感器感应的磁场信号,对所采集的原始信息进行傅里叶变换获取偶次谐波,得到罗盘方位值。计算结果表明:二次谐波的波形幅度在各偶次谐波中最大,其提取精度至少提高5倍,而且采用多个偶次谐波并行使用解算方位的方法,降低了原始噪声,增大了原始信息的利用率,提高了磁通门传感器的灵敏度,因此,数字信号处理方法可行。     

高等职业技术院校图书馆定位问题探讨

文中论述了高等职业技术院校图书馆定位研究的必要性.并结合广东交通职业技术学院图书馆具体情况,探讨了高职院校图书馆定位研究的主要内容.     

减速齿轮箱安装精度控制技术在实船上的应用

新型舰船动力系统的许多重要设备属于研制产品,设备的安装质量是整个工程的关键,为使设备安装达到质量要求,运用平面方程计算程序,对舰船减速齿轮箱装置安装精度的控制技术进行了应用研究。该精度控制技术的方法简单,安装成本低,控制精度高并且控制方向准确。     

我国铁路网运营的相对有效性评价分析

为量化分析我国铁路网运营的有效性,利用评价经济系统相对有效性的数据包络分析方法,就铁路网近年来运营的相对有效性进行了分析评价。从投入产出的角度,通过计算决策单元未充分利用的资源投入和产出指标输出不足的数量,分析决策单元非相对有效的原因,获得某些有关改善路网运营效率的管理信息;还就我国铁路网运营的有效性与国外主要国家铁路进行比较。结果表明,随着铁路网规模的扩大,路网质量的提高,尤其是近几年一系列运营组织措施的实施,不仅整个路网的运营有效性在提高,而且大多数铁路局(公司)所在路网的运营也是相对有效的;与国外主要国家相比,我国铁路网也是运营很有效的路网之一。     

我国铁路融资制度改革方向探讨

我国《中长期铁路网规划》的制定和实施，每年需要巨额的资金投入，传统的融资方式已经制约了铁路的又好又快发展。此文通过对我国铁路当前融资制度存在问题的剖析，提出了铁路融资制度改革的关键点在于铁路的分类建设和分类经营。以期通过改革当前的制度，实现铁路融资渠道的拓宽，广泛吸引民间资本，加快铁路建设的进程。