相应点

If the observer is at a great distance compared to the other dimensions of the experiment and the rays are nearly perpendicular to the reflecting surfaces, then the path difference between the two waves (corresponding to r1-r2 in the preceding section) is just twice the thickness d of the air wedge at each point.

如果观察者比起实验装置来讲距离较远而且光线较接近于垂直反射于表面，那么这两光波的光程差(在前面所述的相应部分 r1-r2)就仅仅是空气劈尖在该点处的厚度 d 的两倍。

The observer is at a great distance compared to the other dimensions of the experiment and the rays are nearly perpendicular to the reflecting surfaces, then the path difference between the two waves (corresponding to r1-r2 in the preceding section) is just twice the thickness d of the air wedge at each point.

如果观察者比起实验装置来讲距离较远而且光线较接近于垂直反射于表面，那么这两光波的光程差(在前面所述的相应部分 r1-r2)就仅仅是空气劈尖在该点处的厚度 d 的两倍。

During the reaction of alkylation, general contained 0.2%~2.0% butadiene will produce viscous heavy composite materials, which will raise final boiling point of alkylate and decrease octane, what is more, it will react with acid to produce corresponding ester, which will increase the consumption of acid, Therefore, we must remove butadiene by selective hydrogenation, at the same time, it will convert some of 1- butane to 2- butane by isomerization and raise octane of alkylate.

一般含有0.2%~2.0%的丁二烯，其在烷基化反应中，可生成一种分子量很高的粘稠重质迭合物，使烷基化油的干点升高，辛烷值降低，并且它还和酸反应生成相应的酯而加大酸耗量。因此必须经过选择性加氢除掉丁二烯，同时，将部分1-丁烯异构化为2-丁烯，以提高烷基化油的辛烷值。

By Giemsa--C technique, the chromosomes of Aegilops tauschii (85A-34) and Hordeum vulgare (H2) and Ae.tauschii- H.vulgare amphidiploid were all produced clear bands, the terminal band, centromeric band, secondary constrition band and rich intercalary bands were displayed distinctly, thus the corresponding Giemsa-C banding patterns were confirmed.

利用Giemsa--C带显带技术，节节麦、大麦、节节麦-大麦双二倍体都显示出了清晰的带纹，都具有端带、着丝点带、随体带和丰富的中间带，相应的确定了它们的Giemsa--C带核型。

The basic approach of protecting people from being hurt or killed in an accident is to improve crashworthiness of vehicles. This paper starts with discussing theories and methods for vehicle passive safety design, which included experiential methods, analytic methods, multi-body dynamics methods, crash test methods and the finite element method. Emphasis will be paid to the basic FEM theories and algorithms of impact problems. Topics discussed include the governing equation, element discretization, hourglass control, time integration, material model, shell element algorithms and contact-impact algorithms. For more reliable simulation results, this paper then conducts study on how to accurately get material model parameters by combining the FEM method with experimental method, and develops relevant material test machine and parameter calculating software. Based on that, basic typical impact simulation and test validation study are conducted. On the basis of the above work, the paper studies the thin-shell structures'crashworthiness, which was affected by the following factors: spot-weld features, shell thickness, cross-section and pre-deformation. As to vehicle parts'crashworthiness, the paper conducts simulation study of designing energy-absorbing steering system and adaptive airbag system. A practical energy-absorbing steering wheel is designed as an example. In further depth research, the paper suggests several inverse quantificational methods for vehicle crashworthiness design based on the ideal crash characteristics. The above theories and methods are applied with good results through several practical vehicles' crashworthiness design and improvement.

文中对汽车碰撞安全性的设计理论和方法进行了归类和总结，其中包括经验法、解析法、多刚体动力学法、试验法以及有限元方法等；重点介绍了碰撞有限元法的基本理论和有关算法，涉及到有限元求解控制方程、单元离散、沙漏模态控制、时间积分、材料模型和应力修正、薄壳单元算法以及接触碰撞界面算法等，探讨了有限元计算中的材料模型参数获取技术，开发了相应的材料试验装置及材料模型参数反求软件，在此基础上进行了基本的碰撞仿真算例和试验对比研究；文中通过应用有限元方法研究了薄壁构件的碰撞吸能特性，指出了设计薄壁吸能构件时需要考虑的几个主要影响因素，即焊点、壁厚、横截面和预变形等；在关于车辆部件的碰撞安全性能设计中进行了吸能转向机构和自适应安全气囊的仿真研究，提出了吸能转向机构和自适应安全气囊的仿真研究方法；文中最后探讨了整车碰撞性能的设计与改进方法，提出了以理想碰撞特性为目标，采用分段加速度或者根据碰撞时间进行设计的反推设计法、部件吸能仿真优化设计法等量化设计方法，并通过综合应用文中所讨论的相关技术进行了整车碰撞性能的设计与改进实例研究，所选定的车型是大众化的普通轿车和碰撞安全性基础较差的微型面包车，研究结果表明，本文所提出的设计与改进方法是适用而有效的，具有重要的工程实用意义和价值。

In this chapter, the existence and uniqueness of the solution to the scheme, the convergence and stability to the scheme are proved by using discrete functional analysis theory, the apriority estimate method and the Brouwer fixed-point theory.

在本章中，运用离散泛函分析理论，结合先验估计、Brouwer不动点原理证明了相应差分格式解的存在唯一性、收敛性和稳定性。

On the basis of the 1 degree girded data of the seasonal mean temperature and salinity at standard levels in the South China Sea, mean Brunt-Visl frequency profiles were derived in order to compute numerically the vertical normal-mode for different seasons in various part of the South China Sea, and the associate linearized equation for horizontal large-scale waves is solved numerically with a improved thompson-Haskell algorithm.

根据南海1°×1°网格的标准层季节平均温、盐度资料，在未引入Boussinesq近似条件下，采用改进的Thompson-Haskell算法求解线性化斜压海洋水平大尺度波的垂直结构方程，从而得到了南海各网格点的第一斜压重力波相速度和相应的罗斯贝变形半径，并探讨其地理分布和季节变化特征，以期有助于南海环流和中尺度涡旋以及有关海洋侧边界效应的研究。

The main contents of this paper are organized as follows. At first, we investi-gate the stability and Hopf bifurcations by analyzing the distribution of the rootsof associated characteristic equation.

本文研究的主要内容为：首先通过分析相应特征方程根的情况，来考察不动点的稳定性及Hopf分支存在性。

The expert suggested that if presented the eye to do and so on symptoms astringently , may select eye drops and so on artificial tear fluid , the major and medium elementary student may make ocular gymnastics , has the condition to be possible to arrive at the hospital to make the corresponding ophthalmic testing .

专家建议，如果已出现眼睛干涩等症状，可点人工泪液等眼药水，大中小学生可做做眼保健操，有条件的可到医院做相应的眼科检查。

By further discussing the asymptoticality of" medial point" for mean value theorem in some references, several new asymptotic estimation formula are obtained under weaker conditions, which unify and extend corresponding results in the references.

对文献中的"中间点"渐近性的有关结果作了进一步讨论，获得几个新的在更弱条件下的渐近估计式，从而在很大程度上推广了文献中的相应结果。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。