查询词典 ray velocity

The average desired velocity of the drivers has been assumed to be proportional to the instantaneous velocity by M ndez and Velasco when a alternative model was proposed. Based on this postulate, the desired velocity of a single driver delineates to be proportional to the local instantaneous velocity in this paper, which is a property of aggressive drivers who all want to drive with the maximum velocity. However, the deriver does not occupy this aggressive characteristic all the time.

基于M ndez 和Velasc关于司机平均期望速度与瞬时速度成比例的假设，认为个体司机的期望速度与其局域瞬时速度成比例，期望以更大的速度行驶，然而并非所有的司机都具有这样的进取特性，为了抑制司机这样的进取特性，引入适应性公式来近似表达单个司机期望速度随时间的变化率。

The main research work of this paper are focused on following areas:(1) Based on review of the theory and methods on measurements of particle fields, a new idea for obtaining particle size and velocity distribution within a spray through imaging the particle field with a laser light sheet was put forward;(2) A DPIV (Digital Particle Image Velocimetry) system, is fit for velocity measurements of low speed flows, was developed and expended to particle size distribution measurement;(3) An arithmetic for particle velocity field reconstruction was developed, and the velocity distribution of water mist was also obtained;(4) A software system for particle analysis, which based on image geometry emend, de-noise and image partition was developed, the parameters such as particle size distribution, mean diameter, number of particles, minimum and maximum diameter can be got with this system;(5) A water mist system was developed and its characteristics, such as droplet velocity, size distribution, number of droplets and spray cone angle under different conditions were obtained from experiments with PIVS;(6) The measurement results of water mist characteristics with PIVS were compared and analyzed with the simply simulated results, and in addition, in order to verify the accuracy of PIVS, some experiments were conducted with the standard particles, such as glass-ball with known mean diameter of 50μm and 115μm, metallic coated tracing particle with mean diameter of 12μm;(7) Some experimental studies on interaction of water mist with liquid pool fires were conducted.

本论文的主要工作包括以下几个方面：（1）在对粒子场测量的相关理论和具体方法进行综述分析的基础上，提出了通过采用激光片光对粒子场进行成像以获取其粒径和速度等参数分布的新思路；（2）研制了适宜于低速流动速度场测量的DPIV(Digital Particle Image Velocimetry)系统，并使其实现了对粒子场粒径分布的测量功能；（3）研制了基于粒子运动轨迹的速度场重建算法，获取了细水雾雾场的速度分布；（4）研制了基于几何校正、去噪、图象分割等图象处理方法的"粒度分析软件系统"，该系统既可分析给出粒子场的粒径分布直方图和平均粒径，还可给出粒子的数目以及最大、最小粒径等信息；（5）建立了一细水雾发生系统，并应用上述方法对不同压力条件下细水雾系统的雾场特性（如速度分布、雾滴粒径分布、雾滴的数目、喷雾张角以及雾化长度等）进行了实验测量研究；（6）对细水雾特性参数的PIVS测量结果与计算机简单模拟计算结果进行了定性比较分析，并利用平均粒径为50μm和115μm的玻璃球以及12μm的标准示踪粒子对PIVS系统的粒径和速度测量结果进行了实验验证，同时对其局限性进行了分析讨论；（7）对不同工况条件下细水雾与油池火相互作用的过程进行了模拟实验研究。

Therefore the dispersion curves obtained in the field are primarily consisted of the first mode. For a heterogeneous elastic solid consisting of three homogeneous layers whose interlayer has low velocity, the phase velocity V〓 of the first mode will also close up to the Rayleigh wave velocity of the bottom layer when frequency f→OHz, but V〓 of the first mode will close up to the shear wave velocity of the interlayer when f→∞, and there is a cut-off frequency at high frequency region for the first mode and V〓 close up to the compressional velocity of interlayer when interlayer is liquid.

当三层固体介质中存在软夹层时，若f→OHz，则其基阶模式的相速度V〓→V〓（V〓为最底层介质的瑞利波速度）；若f→∞，其基阶模式V〓→V〓（V〓为中间层介质的横波速度）；若三层介质中存在液体夹层，当f→OHz时，基阶模式V〓→V〓，而基阶模式在高频段存在一个截止频率，截止频率处的瑞利波速度V〓→V〓；由此可判定，野外实测的相速度频散曲线不仅有基阶导波模式，同时还应有高阶导波模式波的存在，接收信号中存在模式间的跳跃，因此频散曲线会产生"之"字形现象。

Results show that floes' VC and D at the surface water were closely related to current velocity; and the peaks of VC lag those of the current velocity. The lag variation during ebb and flood tides is 10-30min and 30-50 min, respectively. Current velocity at 50 cm/s is a turning point of D vs. vertical average current velocity, before the point, Dm increases with current velocity, and decreases after the point. Similarly, VC at 75μl/L becomes a critical point in the surface water, below the point, D increases with VC, and above the point, D stabilizes.Δp is D dependent, larger floes have much lower Δp than smaller floes. Both D and Δp of floes affect ω. In the surface water during spring tide and neap tide, a power exponent relationship exists between Δp and D, and ω and D.

研究表明：①长江口徐六泾表层絮凝体体积浓度主要受水流流速影响，再悬浮现象明显，体积浓度过程线滞后流速过程线，落潮期间滞后10-30min，涨潮则滞后30-50min；②小于一定流速时絮凝体平均粒径随流速增大而增大，大于一定流速时絮凝体平均粒径则随流速增大而减小，徐六泾夫、小潮表层絮凝体在50cm/s的垂线平均流速时出现平均粒径与垂线平均流速关系的转折；③徐六注大、小潮表层絮凝体平均粒径在体积浓度75μl/L时出现平均粒径与体积浓度关系的转折，体积浓度小于75μl/L时粒径随体积浓度增加而增大，超过75μl/L时粒径随体积浓度的增加变化不明显；④絮凝体有效密度由粒径大小控制，粒径大，有效密度小，反之亦然，粒径和有效密度共同决定絮凝体静水沉速，有效密度和沉速与平均粒径之间均存在良好的幂指数关系。

It was suggested that aging did not only influence diastolic filling period, but also influence STI. 3. With increasing age, whether at rest or during exercice, fractional shortening of minor semiaxis, mean velocity of circumferential fiber shortening, cardiac index and ejection fraction did not change, but immediately post pacing, PEP prolonged and PEP/ LVET increased in elderly group and did not change in young group. It was suggested that STI was sensitivity in detecting systolic function of LV. 4. There was a good correlation between aging and decreased compliance and diastolic function of left ventricle which was manifested by a reduction of early diastolic peak folw velocity, time-velocity integral of early diastole, 1/3 filling fraction (1/3FF)(r=-0.958,-0.875 and -0.937, P＜0.01～0.001) and a significant compansatory increase in peak flow velocity of atrial contraction, time-velocity integral of atrial contraction, the ratio between APFV and EPFV and the ratio of ATVI and Total TVI (r=0.958, 0.956, 0.966 and 0.986, P＜0.001) and the prolongation of Dec T and RFP with increasing age. It was particularly true for the subgroups above the age of 50 years.

静息状态下收缩时间间期与年龄无相关性，负荷后即刻，老年组射血前期延长(P＜0.05)，射血前期与射血期比值加大(P＜0.05)，青年组无变化，提示年龄因素亦影响STI，但由于静息状态下得到代偿，STI变化往往表现不明显。3、静息及负荷状态左室短轴缩短率、平均周径缩短率、心指数及射血分数均不随年龄增长而变化，而负荷后即刻老年组PEF延长，PEP/LVET加大，提示STI是检测左室收缩功能的敏感指标。4、随年龄增长，心房收缩期充盈峰值流速、流速积分、充盈分数及心房收缩期与舒张早期充盈峰值流速之比值显著增高(r＝0.958、0.956、0.986及0.966，P均＜0.001)，舒张早期充盈峰值流速及流速积分、1/3充盈分数(1/3FF)下降(r＝-0.958、-0.875及-0.937，P＜0.01～0.001)。

The tidal river discharge observing system of this thesis gives a new method and experience of the hydrology observing to the river reach and cross section with complicated landform and flow, or busy shipping. This system has achieved 3 innovations: instruments for measurements which use the unmechanized rotor and continue measuring ADCP as the velocity mainframe; methods of velocity measurement which change the vertical velocity measurement to horizontal velocity measurement; the tidal discharge measurement which solve the problem that current method of discharge measurement can not achieve the accuracy of the criterion according to the continuous real time observing over the velocity of flow.

本论文研究的感潮河流流量监测系统，具有测验设备的创新，用可连续测验的非机械转子式的声学多普勒流速剖面仪为测速主机；流速测验方式的创新，改变以往测取垂向流速为水平流速的方式；潮流量测验方式的创新，对流速进行连续实时的监测，解决了用现行测流方法达不到规范要求精度的问题；为地形、水流复杂或是航运频繁的测验河段和断面，提供水文监测的新方法、方式和经验。

In order to probe the relationships between wave equation offset domain common image gathers/angle domain common image gathers with migration velocity, we quantitatively derive the changes of ODCIGs and ADCIGs along with migration velocity on the assumption of uniform velocity medium with a horizontal reflector. We come to conclusion that ODCIGs are hyperbolas with half offset; on the contrary, they are ellipses. Combined with the results of depth focusing analysis, we find the apparent incident angles in ADCIGs are larger than the real incident angles when the migration velocity is larger than the true one and vice versa. With lower migration velocity, the residual moveout on ADCIGs is an ellipse with the tangent of apparent incident angle; otherwise, it's a hyperbola.

为了得到波动方程偏移距域共成像点道集和角度域共成像点道集与偏移速度的关系，在匀速单层水平反射情况下，对ODCIGs和ADCIGs随偏移速度的变化进行了定量的推导，得到偏移速度偏小时ODCIGs与半偏移距成双曲关系，反之成椭圆关系；结合深度聚焦分析，得到偏移速度偏大时ADCIGs中视入射角大于真入射角，反之，小于真入射角；在速度偏小时，ADCIGs上剩余时差与视入射角的正切值成椭圆关系，反之成双曲关系。

When gas superficial velocity was about equal to liquid superficial velocity, the probability density function of liquid holdup had a twin-peaked, when liquid superficial velocity was constant, one of the peaks would fade out and disappear with the in crease of gas superficial velocity. Through using the characteristics, the relative size of gas and liquid superficial velocity can be set initially.

在段塞流动中，当气相折算速度和液相折算速度相差不大时，持液率概率密度函数呈双峰分布；当液相折算速度不变时，随着气相折算速度的增大，持液率概率密度函数第2峰值逐渐减小，直至消失而变为单峰分布；利用这一特征可初步确定段塞流动中气、液相流量相对大小。

It consists of fitting seismic ray traveltimes and positions to data calculated by ray tracing. In order to improve inversion stability and efficiency, seismic ray is described by Hamilton function and ray tracing is done in phase space. Validation tests on synthetic and practical data are analyzed. The tests show that this tomographic method is effective for estimating velocity field in complex media.

为提高反演的稳定性和计算效率，引入了Hamilton函数描述射线，在相空间计算反演所需的射线路径和目标函数对模型参数的导数，对理论模型和实际地震资料进行了试算，试算表明该方法对复杂介质具有较强的适应能力。

Results Compared high kV X-ray chest film with spiral CT,to simplex silicosis,X-ray films coincided with CT scans;to mixed silicosis,the effect of CT scans were better than X-ray's;to large nodule,coalesced progressive massive fibrosis,the detected ratio of CT scans were higher than X-ray chest films;to silicosis complication,for example,emphysema,pleural thickening,phthisic,mediastinal impairment lympy node etc,CT scans were more reliable than X-ray films,especially HRCT can earlier find silicotic nodule and fine structure of focus.Selective application of CT scan,had great diagnostic value in complicated silicosis and silco-tuberculosis and lung cancer complicated with silicosis etc.

结果 高千伏X线胸片与螺旋CT作对比，结果对单纯矽肺并发肺癌，CT片与X线胸片基本一致；对于复杂矽肺并发肺癌CT优于X线胸片；对于大结节、肺内进行性大块纤维化(progressive massive fibrosis，PMF)融合、空洞及钙化CT检出率明显高出胸片；对矽肺并发肺癌的合并其他如肺气肿、胸膜肥厚、结核、纵隔淋巴受累等CT均较胸片可靠；特别是HRCT能早期发现矽肺肿块样病灶中细微结构，选择性应用CT，对复杂矽肺并发肺癌合并结核等鉴别诊断有很大价值。

The witness also told the jury at the Royal Courts of Justice in London that he saw a paparazzo fighting with a member of the public who was trying to stop him taking pictures in the minutes before the emergency services arrived.

他还告诉在伦敦皇家法庭的陪审团，在急救服务到来之前，他当时看见一个狗仔队正和一群阻止他拍照的人打架。

The entire N／C program on a tape is made up of an accumulation of these successive data blocks.

纸带上的整个数控程序由这些连续数据单元连接而成。