瞬时条件

The main work and the originality points of this dissertation could be concluded as the following parts:(1) To analyze systematically the mathematical model of LES of air flow in great space, under the case of isothermal and non-isothermal, as well as the combined action of buoyancy and strain. Some basic problems are studied about the LES application into airflow simulation of great space, such as boundary conditions, spatial difference scheme and time advancing scheme, time step etc., which creates the basis for the LES application to indoor airflow simulation.(2) Both the instantaneous and time averaged flow field of great space with multiple jets under isothermal and non-isothermal cases are explored with large eddy simulation method, and also discussed the dynamic characteristics and the law of fluidflow in the great space.(3) Based on the results of LES of the great space and the Fanger thermal comfort indexes, it is brought forward the concept of the series of dynamic thermal comfort evaluating indexes, which could be divided into thermal comfort index with time averaged properties PD, PPD, PMV, thermal comfort index with instantaneous properties IPD, IPPD, IPMV, and time averaged thermal comfort indexes TAPD, TAPPD, TAPMV, and transient situations time averaged thermal comfort indexes TTAPD, TTAPPD, TTAPMV. The differences among them and the calculation methods are discussed, and the four kinds of indexes are calculated with the thermal comfort index PD as an example.(4) Based on the LES results it is discussed the hot air stratification phenomena in air-conditioned buildings in the case with air supply and return registers on the ceiling and the case on the sidewall. The fundamentals of the hot air stratification are studied and the relations of estimating hot air stratification are brought forward.(5) With the advanced apparatus such as hot wire film anemometer IFA300 and laser particle field anemoscope, corresponding model test and site measurements have been done, which are compared with the simulation results and LES is proved a very promising method in air flow simulation indoor.

本文主要工作既创新点体现在以下几个方面：(1)系统分析了等温、非等温和考虑剪切力与浮升力综合作用的高大空间大涡模拟数学模型，并研究了高大空间大涡模拟在室内气流仿真应用中的一些基本问题，如边界条件、空间离散格式和时间推进格式、时间步长选择等问题，为大涡模拟在室内气流计算中的广泛应用打下了基础；(2)首次用大涡模拟方法研究了高雷诺数下高大空间多射流在等温、非等温情况下的瞬时流场和时均流场分布，并探讨了多射流流场的动态特性和流动规律；(3)基于大涡模拟的动态仿真结果和Fanger的热舒适指标，首次系统地提出了动态热舒适评价指标体系的概念：即基于时间平均参数的热舒适指标PD、PPD、PMV；基于瞬时参数的瞬时热指标IPD、IPPD、IPMV；基于时间平均热舒适指标TAPD、TAPPD、TAPMV；以及沿行动迹线的时间平均热舒适指标TTAPD、TTAPPD、TTAPMV，并分析了四类热舒适指标的差异性和计算方法，还以PD值为例对四类指标分别进行了计算；(4)基于数十种工况下空调房间大涡模拟的结果，研究了空调建筑上送上回和侧送侧回两种情况下热分层现象，并探讨了热分层的基本规律，首次提出了避免热分层现象的判断公式；(5)在暖通空调领域，首次使用IFA300热线风速仪、激光粒子速度场仪等先进设备，完成了与大涡模拟相对应的模型试验，并把实测结果与仿真结果进行了对比，说明LES在室内气流仿真方面是一种很有前景的方法。

The performance of EFT is investigated, which indicates that time-frequency distributions using single-sided window could not accurately trace the variation of the instantaneous frequency, since their performance depend only on the history of the signal, so they are biased frequency estimator.

提出了基于对称阵元互Wigner分布平均的瞬时频率估计算法，这种方法利用多通道数据对时频分布的瞬时频率估计方法的性能进行了有效的改善，并且能够在低信噪比的条件下获得良好的估计效果， 6。

Power-law fluid is used to describe the Non-newtonian rheological property of the produced fluid in a polymer-driving well; the governing equations, boundary and initial equations of power-law fluid in eccentric annuli with the inner cylinder reciprocating axially is established in bipolar coordinates system; formulas of instantaneous flow rate and stress distribution on the outwall of the inner cylinder of the unsteady flow of power-law fluid in eccentric annuli with the inner cylinder reciprocating axially are established.

在理论上，用幂律流体模型描述了聚合物驱油井产出液的非Newton流变性；建立了双极坐标系下幂律流体在内管做轴向往复运动的偏心环空中非定常流的控制方程及边界条件和初始条件方程；建立了双极坐标系下幂律流体在内管做轴向往复运动的偏心环空中流动时瞬时流量和流体在内管壁上的压力分布计算公式。

In this paper,an improved method of optical flow estimation is proposed under the condition of the basic constraint equation and the smooth constraint.

本文在基本约束方程和平滑性约束条件下，提出了一种改进的瞬时位置速度估计方法。

Thus,an ISG HEV vehicle model is set up based on Simulink in the paper.A real time optimization control strategy based on logic threshold is proposed,which is suitable for urban cycle on the basis of analyzing its operation mode.

因此，基于Simulink建立了ISGHEV的整车模型，在分析其工作模式的基础上，提出了适合于城市工况使用条件的基于逻辑门限值的瞬时优化控制策略。

The process of diffusing or the condition of being diffused.

在有条件的切换过程中，瞬时呼叫可能会掉线。

The only alternative and referential way to predict the phase transformation temperature is to make use of the continuous cooling transformation diagrams, which are measured dilatometer curves that have not taken the effect of practical welding conditions into account.

由于焊接过程的瞬时性和焊接热影响区温度场、应力场的复杂性，该区域的组织转变往往并不完全遵守热处理条件下CCT 图所反映出的相变规律，因此为了提高焊接接头的性能，有必要深入研究真实焊接条件下热影响区组织的相变规律，尤其是马氏体组织的相变规律，因为在含碳量较高或合金元素较多的情况下，这两类钢的淬透性较强，在焊接热影响区极易形成高硬度马氏体组织，从而严重影响焊接接头的性能。

And with these results, I delve further into the theoretical issues of MSP and the concentration is on a special class of MSP-Doob skeleton processes. Generalized limit distribution, limit distribution of these processes and conditions and the expressions for the existence of invariable measure of such processes are provided. Finally, these new results are then applied to queueing theory, reliability theory and inventory theory. A detailed study of GI/G/1 queuing model, parallel connection system model, water reservoir model and perishable inventory model is discussed. These models have already been investigated to some degree. In particular, as mentioned above, some scholars have already successfully applied the transient behavior theory of MSP to these models and transient distributions of main variables in such models have been obtained. However, the limit behavior has not been addressed. In this thesis, limit behavior of main variables in the above-mentioned models is established.

在这个基础上，对马尔可夫骨架过程的理论进一步进行了探讨，将注意力集中于一类特殊的马尔可夫骨架过程Doob骨架过程，给出了这类过程的广义极限分布、极限分布以及不变测度存在性条件和表达式，并应用这些结论于排队论、可靠性理论和存储论等领域-具体分析了GI/G/1排队论系统模型、并联系统模型、水库储水模型、易腐烂物品库存模型——这些模型都不同程度地被许多学者研究过，特别，如前面提及，已有人成功地应用马尔可夫骨架过程的瞬时性态理论，获得了上述各模型中的主要参量过程的瞬时分布，但是，却并没有探讨它们的极限性态——建立了若干关于上述各模犁的主要参量过程的极限性态的结果。

Considering the influence of propeller, the applied conditions of the instantaneous angular speed method for fault diagnosis are discussed.

考虑螺旋桨对瞬时转速的影响，分析了瞬时转速分析法用于船舶主机监测与诊断的应用条件。

The conditions for the existence of crank for Watt's mechanism, a basic type of one-degree-of-freedom planar six-bar mechanism,are investigated with the triangular dividing method and the method of instantaneous fixing of the driving bar.

本文采用平面杆机构的三角形划分法及主动杆瞬时凝结法探讨了单自由度平面六杆机构的一种基本型式——Watt型机构的曲柄存在条件；并用取极限的方法得到了其诱导机构的曲柄存在条件。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。