清8出汊后河口拦门沙演变及疏浚治理措施

1996年实施清8人工出汉工程后,新口门水沙条件和海洋动力条件发生了很大变化,拦门沙发育演变情况也随之变化。从实测资料出发,根据河流动力学和海洋动力学原理,分析了新口门拦门沙的发育演变特点和新口门拦门沙对河道泄洪排沙、填海造陆的影响,探讨了拦门沙疏浚治理措施。     

BJ-RUC在内蒙古某风电场的风速预报检验分析

采用趋势性及误差、偏差频率、误差反位相等分析方法,以2011年6月1日~2012年5月31日内蒙古某风电场风机轮毂高度逐小时风速资料为实况数据,对9 km×9 km BJ-RUC风速预报产品的连续变化趋势及误差分布进行了初步评估,发现:(1)预报风速与实况风速在夏季的相关性较差,其余3季预报风速的连续变化趋势性能较好。(2)平均误差在各月均以正为主,即预报风速总体较实况风速偏大,两者存在明显的系统性误差,春夏两季误差大于秋冬两季。(3)随着预报时效的延长,预报性能总体呈下降趋势。     

Catastrophic reduction of the oyster,Tiostrea chilensis (Bivalvia: Ostreidae), in Foveaux Strait,New Zealand,due to infestation by the protistan Bonamia sp.

Between 1985 and 1992, mortality due to infestation by the protistan Bonamia sp. severely reduced the numbers of the oyster, Tiostrea chilensis in Foveaux Strait, New Zealand. In 1990, two dredge surveys gave relative estimates, and a dive survey an absolute estimate, of the size of this oyster population; this allowed us to estimate dredge efficiency precisely. This estimate was used to re‐evaluate the dredge survey of 1975–76 and relate the size of the population in 1990 to that in 1975. By 1990 the population density had declined by 67% while a dredge survey in 1992 showed that the population density had declined by 91% from 1975. A dredge survey in 1993 showed that the population had increased slightly (but not significantly) over the 1992 level. By 1992 the population had probably been reduced below 10% of the virgin level. The fishery was closed in 1993 to allow the population to rebuild. The population surveys have followed stratified random and grid pattern sampling designs and the merits of the designs and methodology are discussed.     

1.2m地平式望远镜驱动系统设计与多电机同步控制策略

对于大型光电望远镜,多电机摩擦轮驱动方案较单力矩电机直接驱动方案在电机的研制和低速平稳跟踪上有明显的优势,但其关键点和难点在于多电机的同步控制上。在云南天文台1.2m望远镜的方位改造中,通过采用合理的多电机驱动方案和设计同步补偿装置,克服多电机在运行时的相互影响,将稳态运行的转速差控制在一个较小的范围,并为校正参数的设计奠定了良好的基础,保证系统在以最大速度3°/s运行时对目标的高精度跟踪。     

车辆-轨道系统振动响应分析--Timoshenko梁与Euler梁轨道模型的比较

近年来，铁路的高速化、高运量化以及轻微的地震灾害等因素加速了轨道结构的沉降或变形，导致车辆轨道系统振动的加剧。本文运用车辆-轨道耦合动力学理论，编制了基于Timoehenko梁钢轨模型的车辆-轨道耦合振动仿真分析软件，分析了车辆-轨道系统的垂向振动特性，并与基于Euler梁模型的VICT软件的仿真结果进行了比较分析。结果表明：仿真结果与VICT的仿真结果基本一致，但在较高频域，前者能更好地反映轮轨系统的高频特性。因而，在研究轮轨高频振动及轮轨噪声时。采用Timoshenko梁钢轨模型更具合理性。     

Granitic and monzonitic rocks dredged from the southeast Australian continental margin

Four Middle Devonian (381 Ma) granodiorite samples have been recovered from two dredge sites approximately 65 km east of Green Cape, New South Wales. The granodiorite samples are similar in age and composition to members of the Moruya Suite and probably form an along‐strike extension of that suite. The location of granodiorite on the southeastern margin requires that a piece of continental lithosphere was located to the present east of the study area in the Devonian. This piece of lithosphere may now be located somewhere on the western Lord Howe Rise.

A sample of Early Cretaceous leuco‐quartz monzodiorite was also recovered from a dredge site approximately 45 km north‐northeast of Dalmeny, New South Wales. It represents a body that was intruded at essentially the same time as, and is inferred to be of similar origin to, the syenite rocks of the nearby Mt Dromedary and Montague Island complexes.     

A bucket wheel dredge system for offshore tin mining beyond the 50 m water depth

A bucket wheel dredge (BWD) for offshore tin mining is part of the long term plan of PT Timah Tbk to identify new dredging technologies for mining in greater than 50 m water depths. Measured tin-ore physical properties are used in a new BWD computer model to investigate deep water tin mining. The model simulates the cutting and hydraulic transport of submerged tin-ore. The results show that hydraulic tin mining beyond water depths of 50 m is feasible. It is best to employ hydraulic transport for lifting the tin-ore from the ocean floor to the surface and to use barges to transport the tin-ore to land processing plants.     

多传感器与道路网数据用于汽车导航的研究

对车载导航系统中GPS接收机，车论计数器和电子罗盘传感器数据与导航电子地图所提供的道路网络数据进行了综合处理，建立了道路网络数据的网络拓扑关系，在此基础上提出了基于道路网络拓扑关系，利用GPS接收机，车轮计数器和电子罗盘传感器对汽车进行实时定位的算法。最后，对导航中汽车的定位误差进行了分析。实验证明，GPS接收机，车轮计数器和电子罗盘传感器与道路网络数据综合，在导航过程中能够补偿GPS信号技失，实时、高精度、高可靠性地确定汽车的位置。