A New Implementation of the Post-Stage Tasks of Motion Estimation Using SIMD Architecture

IntroductionThe MPEG2 [1] video compression standard is oneof the key technologies for applications such asdigital broadcasting,storage media,etc.Recently,some single chip video encoders havebeen developed for the MPEG2 standard. Thedevelopment of hardware architecture suitable forsystem integration is the key to single chipimplementation.Motion estimation/compensation is the keypart of a single MPEG2 video encoder chip. It hasa great impact on the chip size,the powerdissipation,and the …     

汽轮机通流部分清洗技术在6MW机组中的应用

通过对霍州煤电煤矸石热电厂2#汽轮机组推力瓦温度高原因分析，得出其主要原因为通流部分结垢严重，流通不畅，导致汽轮机做功能力下降，使机组无法带至额定负荷；并对通流部分结垢的原因进行分析、研究，作出清洗处理，有效降低了机组运行中的推力瓦温度，以提高机组的安全经济性。     

Sedimentation processes and sedimentary characteristics of tidal bores along the north bank of the Qiantang Estuary

A tidal bore is a unique Earth surface process, characterized by its highly destructive energy, predictable periodicities and magni-tudes, and the production of characteristic sedimentary features. Tidal bores and associated rapid flood flows are highly turbulent flows of the upper-flow regime with a velocity over several meters per second. Reynolds (Re) and Froude (Fr) numbers, respectively, are larger than 104 and 1.0, making them significantly different from regular tidal flows but analogous to turbidity currents. Until now, understanding of tidal-bore depositional processes and products has been limited because of the difficulty and hazards involved with gauging tidal bores directly. The Qiantang bore is known as the largest breaking bore in the world. Field surveys were carried out in May 2010, along the north bank of the Qiantang Estuary to observe the occurrence of peak bores, including regular observations of current, water level and turbidity at the main channel. Several short cores were sampled on the intertidal flats to study the characteristic sedimentary features of tidal bores. Hydrodynamic and sedimentological studies show that the processes of sediment resuspension, transport and deposition are controlled primarily by the tidal bores, and the subsequent abruptly accelerated and decelerated flood flows, which only account for one tenth of each semidiurnal tidal cycle in the estuary. Tidal-bore deposits are generally poorly sorted because of rapid sedimentation after highly mixed suspension by intense turbulence. This behavior is characteristic of the absence of tractive-current depositional components in a C-M diagram. It also goes along with well-developed massive bedding, graded bedding, basal erosion structures, convolute bedding and dewatering structures. Together, these sedimentary features can constitute fingerprinting of turbidites, widely distributed in the deep-water environment. However, a tidal bore is triggered by intensely deformed tidal waves propagating into a shallow-water environment, which returns to regular tidal flows rapidly after the passage of the bore head. The tidal-bore deposits are usually bounded by the intertidal-flat deposits with typical tidal beddings at the top and on both flanks. The difference between tidal-bore deposits (TBD) and tidal sandy/muddy deposits (TSD/TMD) is evident not only in sedimentary structures, but also in the grain-size composition. They can be clearly distinguished in grain-size bivariate plots, typically the plot of mean grain size vs. standard deviation (or sorting). Some trend variations generally exist in mean grain size with TBD>TSD>TMD, sorting with TMD>TBD>TSD (larger value indicating poorer sorting), and both skewness and kurtosis with TSD>TBD>TMD. These findings will undoubtedly shed new light on our understanding of tidal-bore sedimentology, ancient tidal-bore sedimentary facies and environments, and related oil-and-gas field prospecting.     

单点系泊物体长周期运动的统计研究

本文根据实测数据分析了单点系泊物体绕系泊点作360°回转的概率,统计了系泊船船向与风向的相关性。结果表明,在一般海域作360°回转的概率是很小的;船向与风向的相关系数为0.826,因此作者认为,引起360°回转的主要原因是风,实用上可以根据主风向的回转概率或风玫瑰图来推断单点系泊物体的回转概率。     

大型水轮机推力轴承支架结构优化设计

本文通过对大型水轮机推力轴承支架结构特点的分析,提出了大型水轮机推力轴承支架结构优化设计的数学模型.这是一个有尺寸、应力及位移约束的结构优化问题.本文采用复合形法迭代求解,采用自编的推力轴承支架的结构分析和优化设计的程序系统进行计算,得出最优解.     

河流污染物横向混合系数的模拟研究

本文在实验室矩形明渠物理模型内进行了示踪试验,获得了大量的实验数据,确定了关于横向混合系数的准数关系式。通过对国外模型试验和现场试验资料的分析,认为该准数关系式能较好地适用于天然顺直河流,具有一定的实用价值。     

十八重溪野生植物资源的研究

在调查研究的基础上，笔者统计了十八重溪维管束植物，计有１５９科，４７９属，８２９种。其中蕨类植物３５科，５３属，９３种；裸子植物６科，６属，６种；被子植物１１８科，４２０属，７３０种，在调查的基础上，分析了种子植物各属的区系成分。根据野生经济植物的用途，把区内野生经济植物分为８类：油脂植物、淀粉及糖类植物、芳香油植物、纤维植物、鞣料植物、观赏植物、药用植物和蜜粉源植物。在此基础上。提出野生经济植物合理利用与保护的设想，为进一步研究十八重溪野生经济植物，以及植物资源合理利用与保护提供基础资料和科学依据。     

燃气轮机性能数字仿真中的Newton-Raphson法的改进

燃气轮机性能数字仿真中常采用 Newton-Raphson 方法的离散形式求解残量方程组.当维数较高时,该方法会产生迭代初值要求苛刻,系数矩阵易呈病态及造代收敛慢等问题.据此,本文提出了若干改进措施.计算表明,它们是可行有效的.     

燃气轮机总能系统热力学分析

通过对典型燃气轮机总能系统热力学分析,认为(火用)效率是各类燃气轮机总能系统具有可比性的热力学完善性指标,通过(火用)分析可查明(火用)损失分布。文中指出提高(火用)效率的主要途径是提高燃气透平进气温度,它是影响总能系统(火用)效率的主要因素,而余热的利用方式对其影响不大。从热能综合利用的角度来看,总能系统宜兼有高的热利率与(火用)效率,因此,对总能系统进行能分析仍属必要。     

闽江口川石水道的水文泥沙特性及其内拦门沙成因分析

闽江口川石水道,口内段落潮流占优势,口外段涨潮流占优势,口门附近是落潮流优势向涨潮流优势转化的过渡地带.由于水流分汊、分歧、扩散、会潮以及盐淡水混合等因素的作用,口门附近水动力条件较弱.该水道在中潮位以下的低水时期泥沙运动活跃,河槽冲淤变化剧烈. 在川石水道的口门上发育着拦门沙,堆积体部分处在口内,部分处在口外,两部分堆积体虽然相连,在外形上是一整体,并统称为内沙浅滩,但是口内外堆积体的形成发育过程有明显的差别.川石水道口门上的拦门沙实原上是由不同原因造成的两个浅滩的联合体.