速度分布

In this paper, It is analyzed that the variation of the density of a molecular system cause influence for the Maxwell distribution law.

本文对分子系统的由分子密度引起的速度分布的变化对麦克斯韦速度分布律的影响进行了分析。

Simulation results show that bubbles induce the circulation of particles in the fluidized bed in which the distribution of particle velocities can be expressed by the Gauss distribution.

计算结果表明床内气泡的形成造成床内颗粒的循环，使得流化床内颗粒具有不同的轴向和径向脉动速度，颗粒分速度分布近似服从高斯分布。

After a century, the kinetic theory of gases was also won the rapid development of .1857, the Clausius for the first time clearly statistical concepts, derived gas pressure, volume and temperature inter-correct relations, but also in 1858 introduced the concept of .1859 free path of molecular motion, the Maxwell velocity distribution law is derived, established the mathematical theory of transport processes .1868, the Boltzmann velocity distribution law was introduced in the gravitational field .

此后一个世纪，气体动理论才又获得飞跃发展。1857年，克劳修斯第一次清楚地说明统计概念，导出了气体压力、体积和温度间的正确关系，还于1858年引入分子运动自由程概念。1859年，麦克斯韦导出了速度分布律，建立了输运过程的数学理论。1868年，玻耳兹曼在速度分布律中引入重力场。

The distribution of linear velocity is a special case of power velocity distribution when the effects of momentum and friction balance each other.

线性速度分布只是幂速度分布在动量和摩阻影响相平衡时的特例。

By analyzing phases velocity profiles and resistance lawv resulted from gas slug in the pipe center,the condition that the secondary flow occurs,phases velocity profiles,formula of drag reduction and a curve of drag reduction have been obtained.

以流体力学基本方程为基础，通过对气体在管道中心形成段塞流的相速度分布和阻力规律分析，得到了二次流发生的条件、各相流体速度分布、减阻率关系式以及减阻率曲线。

Heat transfer and velocity distribution in the flow of a cold,two-dimensional vertical liquid jet against an isothermal hot,horizontal plate were studied,by using similarity transformation and Crocco transformation.

研究了二维冷液体射流垂直冲击一个恒温热平面时，射流沿平面的热量传输和速度分布。通过对Crocco变换加以推广，求得了问题的相似解，揭示了速度梯度，温度分布和剪切力之间的关系。

And the feasibility of the two measurement methods is demonstrated.3 Computer simulation is performed in the situation of air passing by a heating columned thermistor through a round pipeline. The fluid velocity and temperature distributions under different mass flowrate are shown. They reflect the impact the heating thermistor has on the fluid. The velocity distribution on the surface of the heating thermistor is studied and the impact of natural convection is revealed. The lower limit of measurement based on the simulation result is given.

仿真实验结果给出了不同空气质量流量下加热元件周围流体的速度和温度分布，直观反映了加热元件对流动产生的影响；研究了发热元件表面流体的速度分布，揭示了由浮升力引起的自然对流对流量测量的影响，给出了测量下限值的仿真结果；并通过仿真实验数据验证了恒功率热消散式热式流量计的流量方程。

The author thinks that the experimental curves measured by resonant-fluorescence excitation are the velocity distribution functions, but those measured by nonresonant fluorescence excitation are not the velocity distribution functions directly.

作者认为，共振荧光激发模式测出的就是速度分布函数，而非共振荧光激发模式测量的结果不能直接反映速度分布函数。

According to the energy conservation theory, BOM and CSIM4 were coupled. The BOM has no treatment on transmission solar radiation, which is of great importance when the model is adapted to Arctic Ocean. So the treatment was introduced to BOM. Through numerical test on different lead albedos, it was found that sea ice thickness is not so sensitive to lead albedo, which may be contribute to the lead occupies little ratio within multiyear sea ice pack. The reason of summer over-melt of arctic sea ice is the NCEP reanalysis downward solar radiation being larger than its reality. Then the arctic sea ice climate variability was simulated. Results showed that: simulated ice thickness change is in accord with the submarine investigated mean sea-ice draft changes. Simulated annually maximum ice thickness along the Eurasian continental oceans are closely related to the observed ones. The long-term mean simulated ice motion has the same features of the SSM/I derived ice motion. Sea ice extents in differential sub-regions have same trends comparing to the satellite passive-microwave data derived ones. Simulated ice concentration is closely related to the observed in the Arctic sub-regions. Sea ice flux through the Fram Strait involves ice concentration, motion and thickness. It is a composite criterion for sea ice model evaluation. The simulated ice area and volume export through the strait accord with the satellite derived or statistically reconstructed ones.(5) The simulated ice thickness climate variability and mean sea surface current of the coupled model were analyzed, results showed: the total ice volume in the Arctic Ocean has a significant decreasing trend. The volume variability is of a 10-year timescale oscillation, with two major periods of 12-13a and 18-20a. Mean ice thickness in the arctic sub-seas has different tendencies. It has an increasing trend in the Barents-Kara Sea and Baffin Bay-Labrador Sea, and decreasing in the others. The characteristic time scale of 7-10a wherein the river discharges leads the Fram Strait ice volume export is about the period that river water takes to be conveyed across the Arctic Ocean.(6) Using the simulated ice distribution in the Arctic Ocean and China precipitation, air temperature and SST in tropical key regions, the climate teleconnection were studied. Result showed: When the mean sea ice thickness is large in the central Arctic Ocean and Chukchi-Beaufort Sea , and small in the Barents-Kara Sea and Baffin Bay-Labrador Sea , the precipitation in South China, Tibetan Plateau, and the north part of Northeastern China are always smaller than normal, and v. v. When the mean ice thickness is small in CA, BC, East Siberian Sea and Greenland-Iceland-Norwegian Sea , and large in BL, The air temperature in north-eastern China, the southern of Tibetan Plateau, and Hainan Island, are always lower than normal, and v. v. In addition, when the sea ice is thick in BC and BL, the SST is larger in the middle and eastern Pacific Ocean, and is smaller in the tropical Southeastern Indian Ocean.

由于BOM没有考虑透射太阳辐射的物理过程，研究表明透射太阳辐射对北冰洋的能量收支起到重要作用，因此在BOM模式中引入了对透射太阳辐射的处理；通过对不同水道反照率的数值试验表明海冰厚度对水道反照率的敏感性不强，可能与海冰区水道面积占的比率很小有关；而模式模拟的北极海冰夏季&过度融化&主要源于NCEP再分析资料提供了偏大的太阳短波辐射；对北极海冰的气候变率进行了模拟研究，结果表明：模拟的海冰厚度变化与潜艇探测的海冰吃深度变化具有一致性；模拟和观测的亚欧大陆沿海的年内最大海冰厚度有很好的相关；模拟的海冰移速与长期平均的卫星反演的海冰移速具有相同的速度分布特征；模拟的各个海区海冰面积的变化趋势与卫星反演资料分析的结果基本一致；模拟与观测的主要海洋分区的海冰密集度具有很好的相关：弗瑞姆海峡的海冰体积和面积的输送涉及到海冰密集度、厚度和移动速度，是判断模式模拟能力的一个综合的指标，模式模拟的结果与卫星反演或重建的面积输送、体积输送具有很好的一致性；(5)分析了模拟的北极海冰厚度的气候变率及气候平均表层海流场，结果表明：北极海冰的总体积有显著减少的趋势，北极海冰总体积的变化具有10a际尺度振荡的特点，存在18-20a和12-13a两个主周期；北极海冰的平均厚度在各个海区的变化趋势不同，在巴伦支—喀拉海和巴芬湾—拉布拉多海地区海冰厚度有显著的增加趋势，而其它海区存在减少的趋势；通过对模拟的气候平均表层海流的分析表明，北极河流流量超前弗瑞姆海峡海冰流量7-10年的特征时间尺度与表层海流的气候分布存在着必然联系：(6)利用模拟结果以及中国降水、气温和热带关键区SST资料，讨论了北极各海区海冰平均厚度与中国降水、气温以及热带关键区SST的关系，结果表明：在北极中心海区和楚科奇—波弗特海海冰厚度偏大，在巴伦支—喀拉海以及巴芬湾—拉布拉多海海冰厚度偏小，则中国降水在华南地区、青藏高原和东北北部降水偏少，反之相反；在北极中心海区、东西伯利亚海、楚科奇—波弗特海以及格陵兰海海冰厚度偏小，在巴芬湾—拉布拉多海海冰厚度偏大，则在中国东北地区、高原南部地区和海南岛附近气温偏低，反之相反；另外，北极楚科奇—波弗特海和巴芬湾—拉布拉多海海冰厚度偏大时，在热带中东太平洋海温偏高，而在热带东南印度洋海温偏低。

The research of lift-off velocity distribution function of saltating sand grain would redound to solve the random problem of single lift-off sand grain from sand bed and promote the combination between microcosmic researches and macroscopical researches of Aeolian sand movement.

沙粒起跳初速度分布函数的研究成果将有助于解决在错综复杂的沙床面上单颗沙粒运动的随机性问题，初步实现微观与宏观研究的结合；跃移沙粒降落速度分布函数对于反演跃移沙粒与沙床面碰撞的恢复系数，深入理解碰撞过程具有十分重要的意义，同时也将促进击溅函数的修正工作。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。