反自反的

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。

It is the first laboratorial experiment results of self-volume deformation of MgO concrete applied to the arch dam foundation of Dongfeng hydropower station in Guizhou province, the laws of self-volume deformation of MgO concete is conducted, the long-term expansion deformation value is reckoned, the arc tangent curve model of the concrete is presented to describe the characteristics of expansion deformation of the MgO concrete.

本文以在国内外首次将MgO混凝土应用于主体工程的贵州东风水电站拱坝基础混凝土的室内自生体积变形成果为例，对MgO混凝土自生体积变形的规律进行了研究，提出了MgO混凝土自生体积变形的反正切曲线模型，用以表达MgO混凝土的膨胀变形特性和推算MgO混凝土的长期膨胀变形值。

The simulation results show that the vector control system based on this improved scheme has better dynamic and static performance. It solves a lot of problems such as larger error in the MRAS based on the back electromotive force when the motor runs across the zero speed and the instability based on the instantaneous reactive power in the regenerating mode and has high estimating precision.

仿真表明基于该方法的矢量控制系统动静态性能好，能有效解决反电动势模型参考自适应方法在速度过零点辨识误差大以及瞬时无功功率模型参考自适应方法在转速给定为负阶跃时转速不稳定问题，转速估计精度高。

In this article,byJordan-Winger transformation,the weakly dimerized spin-1/2 anti-ferromagneticchain is transformed into quantum sine-Gordon model in the continuum limit.Onthe fundament of self-consistent field the usual field variable and canonical momen-tum are rescaled by using the Bogoliubov transformation.

我们利用Jordan-winger变换，在连续表象把量子二聚化spin-1/2反铁磁链哈密顿变换至sine-Gordon方程，在自洽场理论的框架内利用Bogoliubov变化重新标度了常规场变量和动量，有效地解决了远红外发散问题，自洽地得到了基态能和激发谱。

Based on wake features and operational principle of wake homing torpedo, this paper introduces some methods of soft kill, hard kill and non-kill, such as gas generator, magnetic wake, torpedo net defense, depth bomb, anti-torpedo torpedo, stealth, and evasive maneuver.

该文基于尾流特征及尾流自导鱼雷工作原理，介绍了用于对抗尾流自导鱼雷的气幕弹、磁尾流、拖网、深水炸弹和反鱼雷鱼雷等几种软杀伤和硬杀伤方法以及隐身技术和机动规避等非杀伤方法，总结了舰船对抗鱼雷攻击的3个关键环节包括高性能鱼雷报警系统、快速反应的水声对抗系统和多功能的水声对抗设施，旨在为有效防御尾流自导鱼雷提供思路。

Based on wake features and operational principle of wake homing torpedo , this paper introduces some methods of soft kill , hard kill and non-kill ,such as gas generator , magnetic wake , torpedo net defense , depth bomb , anti-torpedo torpedo , stealth , and evasive maneuver. We summarizes three key points in the defense against wake homing torpedo , including high perfo口nance torpedo alarm system , rapid response acoustic countermeasure system , and multi-functional acoustic countermeasure device , to provide approaches to effectively countering wake homing torpedo.

该文基于尾流特征及尾流自导鱼雷工作原理介绍了用于对抗尾流自导鱼雷的气幕弹、磁尾流、拖网、深水炸弹和反鱼雷鱼雷等几种软杀伤和硬杀伤方法以及隐身技术和机动规避等非杀伤方法总结了舰船对抗鱼雷攻击3 个的关键环节包括高性能鱼雷报警系统、快速反应的水声对抗系统和多功能的水声对抗设施旨在为有效防御尾流自导鱼雷提供思路。

In this article, based on one-dimension Heisenberg model, the unsymmetric bilayer ferromagnetic and antiferromagnetic thin films are investigated by using the interface rescaling approach under nonperiodic boundary condition.

本文以海森伯模型为基础，只考虑最近邻相互作用，在计入外磁场和非周期性边界条件下，应用界面重参数化方法，分别研究了由A、B两层组成的铁磁或反铁磁层间耦合薄膜中的自旋双链系统的界面自旋波及其存在的充分必要条件，重点讨论了体各向异性场和自旋链长度对界面自旋波存在条件的影响。

Secondly, according to the theory of retrieving model using time series and the self-memorization principle, the grey self-memory model based on grey system theory and phase space self-memory model established using chaotic theory are put forward, and the two kinds of models are applied to the analogy and forecasting of hydrologic time series, and the application field of the self-memory model is further expanded from extent and profundity.

更进一步，根据时间序列反演建模基本理论和系统自记忆性基本原理，提出了基于灰色系统理论的灰色自记忆预报模型和基于混沌理论的相空间自记忆预报模型，并应用于水文时间序列的模拟与预测，从广度和深度上更加拓广了自记忆模型的应用范围。

After investigation, the Ministry of Commerce finally arbitrates that the imported wear resistant overlay originated from USA and EU made dumping, the Chinese industry was injured actually, and there is causality between the dumping and the material injury.

对实施临时反倾销措施决定公告之日前，原产于美国和欧盟的进口耐磨纸不再追溯征收反倾销税。对原产于美国和欧盟的耐磨纸征收反倾销税，实施期限自2006年12月13日起5年。

The strongly negative correlation between winter sea-ice extent of Davis Strait and August rainfall of North China turns into bad correlation.

冬季戴维斯海峡海冰面积和北半球夏季、7月500Hpa位势高度场年际关系的年代际变化主要是相关系数分布型的变化：1974年前，相关系数分布型呈一个自新地岛开始经巴尔喀什湖到日本海的&-+-&型，该型和同期华北降水的反相关较好；1974年后，相关系数分布型变为呈自乌拉尔山开始经贝加尔湖到河套的&+-&型，该型和同期华北降水相关差。1974年前，冬季戴维斯海峡海冰面积和北半球8月500Hpa位势高度场的相关系数呈一个自乌拉尔山开始到鄂霍次克海以北分布的&+-+&型，该型和8月华北降水的反相关较好；1974年后，相关在欧亚大陆地区变差，没有明显的相关型，冬季戴维斯海峡海冰面积和8月华北降水关系变差。

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。