查询词典 fluid dynamics

In this paper, the different volume ratio additives'influences on the economy of different fuels as well as the characteristics of combustion and emission have been investigated employing the knowledge about combustion dynamics and chemical reaction dynamics on the base of the gasoline additives application actuality in engine. Dimethyl Carbonate, Diisopropyl Ether and Ditert-Butyl Peroxide are selected as gasoline additives to explore the potential and promotable additives by engine tests in different base fuels.

本文根据汽油添加剂的应用现状并结合内燃机燃烧学、化学反应动力学等知识，选择用碳酸二甲酯、二异丙醚、二叔丁基过氧化物作为汽油添加剂，通过不同基础燃油的发动机台架试验，研究不同添加体积比的添加剂对不同燃油经济性、燃烧特性、排放特性的影响，以探求潜在的可推广使用的汽油添加剂。

We in this project studied module dynamics, physiological integration between modules, and the relationship between module dynamics and environmental change including physical and biological interaction for perennial herb Scirpus mariqueter, annual cotton, and tree species of Querucus fabri.

本项目分别以多年生草本克隆植物海三棱麃草，一年生农作物棉花和多年生高大乔木栎树为研究对象，研究了这几种不同构件特征集合体的构件动态、构件间的生理整合及其对环境变化的响应、构件动态与环境因子的变化关系，构件动态与动物侵食的关系等。

The effects of interspecific competition on the population dynamics of four insect grain Insecp pests (Sitophilus zeamais, Rhizopertha dominica, Tribolium castaneum and Cryptolestes ferrugineus) was studied at 30 ℃, 75％ relative humidity. A regression analysis of the population dynamics was conducted.

在30 ℃、75％相对湿度条件下研究种间竞争对玉米象、谷蠹、赤拟谷盗和锈赤扁谷盗4种主要储粮害虫种群动态的影响，并对种群动态进行回归分析。

Through simulation of the real process of thomcolumbar burst fracture and use of modem dynamics techniques, the present study was (1) to investigate the kinetic relationship between structural damage and impact energy absorption and dynamics mechanism of thoracolumbar burst fracture by quantitative analysis of various injured segments;(2) to explore the instability mechanism of L1 vertebral burst fracture and its injury threshold by three-dimensional analysis of the injured segment with stereophotogrammetry in combination of transient physical parameters, anatomy and image;(3) to explore the corresponding relationships between impact energy, geometry parameters and biomechanics by geometry and biomechanical analysis of thoracolumbar burst fracture, which may provide an objective standard for evaluation of spinal injury severity and experimental evidence for adoption of biomechanical treatment in clinic;(4) to evaluate the fixation effect of different instruments and the effect of intervertebral bone graft on segment fixation by analysis of the threedimensional stability of different internal fixation instruments and their decompression of the spinal canal, which may provide experimental evidence for therapeutical selection for thoracolumbar burst fracture in future; and finally to investigate the effect of various instrument fixation on dynamical characteristics by comparison and quantitative analysis of frequency and amplitude responses, which may provide certain theories and experimental evidence for application of vibration test to judge the stability of the spine.

本研究从胸腰段脊柱爆裂骨折发生的实际过程出发，以现代动力学检测及计算机多通道高性能数据采集分析系统等高新技术为基础，实时量化分析损伤节段的工程参数，揭示了结构破坏与能量吸收的变化规律，探讨了胸腰段脊柱爆裂骨折的瞬态损伤机制；利用三维立体摄像技术，对不同损伤程度的节段进行三维运动分析，结合瞬态物理参数、影像学和病理解剖，明确了〓椎体爆裂骨折的失稳机制及损伤阈值；通过对胸腰椎爆裂骨折的几何学变化及生物力学分析，明确了撞击能量与几何参数、几何参数与生物力学的相应关系，为评判脊柱损伤程度提供了客观标准，为治疗中采取适宜的生物力学方法提供了实验依据；通过对比分析不同内固定器械的三维稳定性和对椎管的减压作用，评价不同器械的复位固定作用，同时比较椎体间植骨对节段固定作用的影响，为今后临床胸腰段脊柱爆裂骨折的治疗选择提供依据；利用振动测试与分析技术，比较及量化分析了不同致伤状况的频幅响应特征，比较分析了各种器械固定对动力学特性的影响，为今后临床建立基于振动测试与分析技术判断脊柱稳定性的诊断方法，提供了一定的理论和实验依据。

It shows that the kinematics and translational dynamics are the same, but they have different rotational dynamics.

分析表明，2种建模方法的运动学方程和平移动力学方程相同，但旋转动力学模型完全不同。

The mathematical models of dynamics for the chemical reaction of methanol and trichloro phosphine and the reactors were established by the study of thermodynamics and dynamics.

实验考察了工艺配比、反应温度、压力、反应时间等工艺参数及工艺设备结构等因素对产品收率和质量的影响。

On the basis of long-term experiment, changes in soil organic C, N and dynamics of soil NO〓-N of cropping systems were investigated in gully area of the Loess Plateau by means of analysis of the 15-year soil samples, crop yield in following crop systems: 1 continuous winter wheat with unmanured , nitrogen, organic manure , phosphorus and organic manure , nitrogen and phosphorus , nitrogen, phosphorus and organic manure , 2 continuous alfalfa, 3 pea-winter wheat rotation, winter wheat-sainfoin rotation, and 4 bare fallow. A model was developed according to the organic C dynamics, and was tested by the long-term experiment.

本文以中国科学院长武试验站的长期试验（始于1985年）为依托，通过对典型处理8-15年的土壤养分、作物产量以及同期降水量等的系统分析，揭示了黄土旱塬区不同种植体系中土壤有机碳、氮的演变规律；阐明了长期施肥条件下土壤硝态氮的迁移积累机理；提出了目前水肥条件下黄土旱塬区冬小麦生产潜力及其提高途径。

The relationship between the tracking error and those auxiliary errors is clearly established when plant relative degree is greater than one and therefore, it can be proved that the influence of averaging filters on a VS-MRAC system can be considered as, in a sense, an unmodelled dynamics. As a result of this, it is shown that the stability analysis of a signal synthesis based VS-MRAC system must be modified to include the 'unmodelled dynamics'.

当对象建模部分相对阶大于1时，得到了系统跟踪误差和辅助误差间明确的关系表达式，进而证明平均值滤波器对系统的影响相当于未建模动态对系统的影响，这表明以往相关文献关于系统稳定性的分析是有缺陷的，没有将平均值滤波器对系统稳定性的影响完全考虑在内； 3。

To solve the nonlinear attitude control problem of a class of spacecrafts, the strongly coupled dynamics model is decomposed into some subsystems and the coupling between the subsystems, unmodelled dynamics and exterior disturbances are regarded as the uncertainty of the system.

引 言空间飞行器的姿态控制系统是一个具有参数摄动和外来干扰的非线性系统。滑模控制(Slidingmode control，SMC)对系统参数的不确定性和干扰具有较强的鲁棒性[1，2 ] ，近来越来越多地被用于对空间飞行器的控制，但滑模控制的输出存在高频抖振。

The recursive least-squares estimation method is used to estimate the parameters in the modelled part of the robot dynamics, and the parameters is used to form the feedback control based upon the so-called"inverse system method". The unmodelled part of the robot dynamics is compensated by a learning control law. This not only increases the learning convergence speed and the control system robustness, but also extends the control method to non-repetitive tasks after sufficient learning.

采用递推最小二乘辩识方法来辩识机器人动力学特性中可建模部分的模型参数，并以此来构成反馈控制策略，而对未建模动特性和未知扰动的影响采用学习控制的方法予以克服，从而提高了学习控制过程的收敛速度和鲁棒性，拓宽了它的适用范围。

Diabetes is a social disease that affects several million people worldwide.

糖尿病是一个社会性疾病，全世界有数百万人罹患此病。

I'll call you on Friday to see if we can reschedule our luncheon meeting at your convenience.

我星期五会给您打电话在您方便的时候我们重新安排我们的午餐约会。