查询词典 method study

This thesis contributed to the comprehensive study of the Finite-Difference Time-Domain method and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies. The work includes mainly three parts: the study on the performance of PML absorbing boundary condition applied to pseudo low frequency electromagnetic problems; the validation of the FDTD method with PML absorbing boundary conditions and the corresponding computer software based on the numerical study of the electromagnetic field of an electric dipole antenna, and its application to the numerical computation of radiated electromagnetic fields in switched mode power supplies; the development of an improved alternating direction implicit finite-difference time-domain method.

在综合前人工作基础上，本文对时域有限差分法及其在开关电源辐射电磁场数值计算中的应用进行了系统的分析和研究，其核心内容包括：伪低频电磁场数值计算中PML吸收边界条件性能的研究；基于基准问题—电偶极子天线三维辐射电磁场，验证了本文构造的基于PML吸收边界条件的三维FDTD法及其计算软件，并应用于高频开关电源辐射电磁场的数值分析；提出了一种改进的交替方向隐格式时域有限差分法。

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。

The study method of the so-called change student, is to direct the student from the study of passive one method direction study process that diversify that study method change, make the student passively absorb the ready-made conclusion this ascend of lesson not, but is a student personally vivid thought activity of plentifulness, experience a fulfillment with the creative process.

所谓转变学生的学习方式，就是指使学生从单一被动的学习方式向多样化的学习方式转变，使学生的学习过程不是被动地吸收课本上的现成结论，而是一个学生亲身参与丰富生动的思维活动，经历一个实践和创新的过程。

In the paper, we mostly studied the change of soil erosion process by a new REE tracer method, based on the theories of hydraulic mechanical subject and radionuclear tracer method, and simulated rainfall was applied to study the sheet erosion changing to rill erosion and the rill erosion process on slope land. The new REE tracer method should be useful to future studying of erosion processes on slope lands.1. Offering and testifying a new REE displacing method to study on the soil erosion of the loess slope.

本文以黄土坡面土壤侵蚀形态演变规律为研究重点，以新的核素示踪技术为手段，采用水动力学与核素示踪技术相结合、室内人工模拟降雨与稳定性REE元素示踪相结合的方法，利用先进的INAA技术，定量研究了不同雨强次降雨条件下细沟间侵蚀向细沟侵蚀的转变过程、细沟发生发育过程，为深入了解坡面侵蚀过程，建立黄土高原土壤侵蚀预报模型提供了研究基础。

In this thesis, I summarize the theoretical calculation method, applied scope and notice of siphonic drainage system, and point out the advantage of siphonic drainage system compared with gravitation drainage system. In the archetype experiment study of siphonic drainage tube, I adopt different tube diameter and different structural height to survey the drainage volume and press in different place. I observe various kinds of flow state, and get chief factors which influence hydraulic peculiarity of system as the tube diameter or structural height, and find out the relevance of factor to flux. I apply CFD Fluent software and adopt standard k-ε model and RNG k-ε model, then use finite volume method and second-order upwind scheme to discrete numerical model, while coupling numeration of velocity field and press is based on SIMPLE. In the numerical simulation of curved part of tube, siphonic drainage tube experiment system and multi-outlet siphonic drainage system, I make research on internal velocity and press of system in different project condition by changing the tube diameter of curved part, negative press value in tube export and improving the quantity of water gutter. This thesis first adopts a method of combining archetype experiment and numerical simulation to study the siphonic drainage system, test and verify the validity of experiment and numerical simulation, and makefurther study on system, it solves the problems of limited testing conditions, and has a logical results, it can provide a valid method for optimizing and designing the drainage tube-net system. The conclusion have referring value for study and design of siphonic drainage system.

本文首先对虹吸式排水系统理论计算方法、适用范围以及注意事项做出总结，并分析了虹吸式排水系统的优势；再对虹吸式排水管道进行原型试验研究，采用不同管径不同立管高度，对系统流量、管道压强进行量测，观察了各种工况下的流态，对其水力特性进行研究分析，找出影响水力特性的落差、管径主要因素以及与排水量的关系；进一步应用计算流体力学Fluent软件，采用标准κ-ε模型与RNGκ-ε模型，计算过程应用有限体积法和二阶迎风格式对数值模型进行离散，速度和压力的耦合采用SIMPLE算法，分别对系统弯管段、虹吸排水管道试验系统、多斗虹吸式排水系统进行数值模拟分析，通过改变管段弯头处半径、管段出口负压值、增加雨水斗数对不同工况下系统内部的速度和压力进行研究；本文首次采用结合原型试验与数值模拟相结合的方法，对虹吸式屋面雨水排水系统进行研究，试验与模拟相互验证，并进行拓展，很好地解决了虹吸式屋面雨水排水系统由于试验条件限制问题，结果正确合理，为排水管网系统设计和优化研究提供了有效的方法，对工程设计有较好的参考价值。

Next the discussion in this study, about an ellipse with an angle of attack and two circular cylinders with different diameters in the flow, the aim of this study is investigated for the ability of the present numerical method by solving the suppression of the vortex shedding flow behind the two-cylinder system which was kind of difficult to reach by a Cartesian grid method. In this study, the suppression of the vortex shedding flow is tested to solve a uniform flow past through two different diameter cylindrical in the flow field with Fractional Step Method and Immersed Boundary Method.The numerical method which we investigated is showed that the results of the problem is appropriable in other literatures.

接著探讨流过具攻角之椭圆柱体流场及流过圆柱抑制涡漩逸出之流场，目的是要研究利用控制圆柱来抑制下游涡流的流场行为，本文采用分步法配合内嵌边界法数值解析一均匀流流经两不同直径的圆柱流场，来测试抑制涡流逸出的问题，根据现有的数值结果发现试验运用了合适的方法且得到令人满意的结果。

The project was based on the influence to the asphalt mixture volumectric property by the different compaction method (Marshall Compaction, Roller Compaction, Gyratory Compaction, Vibratory Compaction), a great deal of the experiments has been done with the consideration of the pratical construction. A lot of studies were carried out, such as the study of asphalt mixture image inquiring technique--"Colour Method", the feasibility study of the application of the 2D digital image processing technique on the asphalt mixture and the utiliztion of this technique on the compacting properties analysis of asphalt mixtures. A good beginning and foundation was made for the application of the digital image processing method on the study of the 3D asphalt mixture voluemetric components constitute.

本项目以研究不同沥青混合料成型方法（马歇尔击实、轮碾压实、旋转压实、振动压实）对沥青混合料体积特性的影响作为切入点，结合实际工程，进行了大量试验，开展了&色彩法&沥青混合料图像获取技术研究、沥青混合料二维数字图像处理技术的可行性研究以及采用该技术分析沥青混合料压实特性等研究工作，取得了一系列研究成果，为采用数字图像处理技术解决三维沥青混合料体积组成特性开创了良好的开端，奠定了坚实的基础。

In the foreword, it is the brief analysis of the creative process of the creative subject, telling readers that what we concern about is the study of the subcreative of the creative subject and the study method and the study content of the dissertation. In the first part, it begins with the definition and the process of the subcreative, stepping into the case study of Ge Fei's subcreative, that is what we will study in the dissertation. In the second part, we try to find out the process of Ge Fei's subcreative according to the study method we mentioned in the foreword through the text analysis of the imago combination and the emotion stream in the Ge Fei's texts. In the third part, we summarize how the times and the readings influence the creative subject, through the analysis of the time when Ge Fei lives and the experiences of Ge Fei's reading. In the epilogue, we generalize the significance of the study of the dissertation, hoping that the Ge Fei's case study we do can give the subsequent researchers some revelation.

全文共有五个部分：引言中通过对创作主体创作过程的简析，提出了本文关注的对象是创作主体的潜创作研究，提出了本文的研究方法和研究的主要内容；第一部分以潜创作的界说和过程入手，进入对格非潜创作的个案研究，即本文的研究对象；第二部分按照引言中提出的研究方法，通过对格非文本中的意象组合和情绪化潜流的文本分析，倒推格非的潜创作过程；第三部分总结性地对格非所处的时代背景分析、对影响格非的阅读经验的梳理，理脉时代和阅读对创作主体的影响和作用；结语是对全篇的总结，简括了对格非潜创作研究的意义，并希望通过格非的个案研究对后来的研究者关注潜创作起到一定的启示作用。

Hot cathode glow discharge chemical vapor deposition is a new method to deposit high quality diamond films with high deposition rate.

中文题名热阴极辉光放电及其等离子体化学气相沉积金刚石膜研究副题名外文题名 Study of hot cathode glow discharge and its plasma chemical vapor deposition of diamond films 论文作者白亦真导师金曾孙教授学科专业凝聚态物理研究领域\研究方向学位级别博士学位授予单位吉林大学学位授予日期2001 论文页码总数139，10页关键词金刚石膜薄膜制备热阴极辉光放电等离子体化学气相沉积馆藏号BSLW /2003 /TB43 /1 热阴极辉光放电等离子体化学气相沉积是我们建立的快速沉积高品质金刚石膜的新方法。

Burstone analysis method study on children with beautiful profile normal occlusion

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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。