查询词典 methods

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。

Chapter 4, lists the teaching cases in teacher's teaching, combined the cases dissecting the teaching methods of mathematics and mathematical cerebration and methods in the point of view of psychology, then infers that to proceed the teaching of mathematical cerebration and methods is necessary. In the other hand, I compared and studied the association between the basic mathematical cerebration and methods and other mathematical knowledge, answer the questions that which mathematical cerebration and methods are more worthy to jut out. At last, infers a mode of the teaching in mathematical cerebration and methods.

第四章列举了教师在授课中的教学案例，结合案例从心理学角度对中学数学教学与数学思想方法教学进行剖析，得出进行数学思想方法教学是十分必要的；同时对中学数学教学中的数学基本思想方法与其它数学知识的关系进行了对比分析，对在中学数学教学中突出哪些数学基本思想方法为好做了解答；最后给出了数学思想方法教学的一个教学模式。

Based on consider hereinbefore, this dissertation discusses several aspects on the problem of the sustainable and optimum exploitation of groundwater resources as follows:①reviewed entirely the origin and evolvement of the concept "sustainable development", stated and commented the study status in queue on"sustainable development"around national and international range, thorough discussed the science connotation about the concept "sustainable development";②looked back and commented across-the aboard some furthest basic concept and proposition related to groundwater resources, put forward self opinions on a few existent mistake points of view and chaos understandings;③expatiated entirely on the content and meaning of the theory of changeable groundwater resources system, contrast with the traditional methods of groundwater resources calculation and evaluation, combined example to show the application of this theory;④thorough analyzed the difficult and complexity to forecast the groundwater resources, fully stated the traditional methods of groundwater resources forecasting, pointed out the characteristic and applying condition of these forecasting method, introduced the main ideas and methods of wavelet analysis developed recently, and the MATLAB software be known as the fifths era computer language, and its accessory wavelet analysis toolbox, applied these methods and tools to analyze the groundwater dynamic curve, adopted the B-J method and Morte-Carlo method, combined with the theory of changeable groundwater resources system, discussed the new view on the forecast of groundwater resources;⑤synthetically analyzed the characteristics and limitations of the present all kind of groundwater manage model, combined mathematical programming, mathematical statistics, random process and the theory of variation system of groundwater resources on the unite optimum attempter of surface water and groundwater, emphasized how to make the model more nicety, more simple, more practicality;⑥analyzed the inside condition and outside condition to assure the sustainable and optimum exploitation of groundwater resources, the inside conditions are the follows: correct resources idea, scientific methods of resources calculation and evaluation, credible forecast methods of resources, exercisable measures of resources management, the outside conditions are the follows: the development idea of high layer, the transform of manage system, the matched policy and rule of law, the adjusted of economy lever, the improve of cultural diathesis, the boosting up of water-saving consciousness and detail measures, the control of population rising, the prevention and cure of water pollute, the renew and rebuild of ecology;⑦scan the sustainable and optimum exploitation of groundwater resources from the high level of metagalaxy, earth system science, and philosophy;⑧point out the more directions on groundwater resources.

它将为制定水资源的可持续发展目标和战略决策提供科学依据，为制定社会、经济可持续发展战略提供理论基础。基于以上考虑，论文主要从以下几方面对地下水资源可持续开发问题进行了比较深入的探讨：①全面回顾了"可持续发展"概念的由来与演变，对国内外"可持续发展"的研究现状进行了述评，并对"可持续发展"概念的科学内涵进行了深入探讨；②对涉及地下水资源的一些最基本的概念和命题进行了全面的回顾和评述，对目前仍然存在的一些错误观点和混乱认识提出了自己的见解；③全面阐述了地下水资源变值系统理论的内容和意义，并与传统的地下水资源计算评价方法进行了对比分析，结合实例具体说明了方法的应用；④深入分析了地下水资源预测预报工作的极端重要性和复杂性，对传统的地下水资源动态预测方法进行了全面的评述，指出了各类预测预报方法的特点及适用条件，对最近二十多年刚发展起来的小波分析技术的主要思想和方法及其应用范围，以及号称第五代计算机语言的MATLAB软件和附带的小波分析工具箱进行了介绍，并应用于地下水动态过程线的分析，采用时间序列中的B-J法，蒙特卡罗方法，与地下水资源变值系统理论相结合，探讨了地下水动态资料分析和地下水资源预测预报的新思路；⑤综合分析了现今各类地下水管理模型的特点及缺陷，将数学规划、数理统计、随机过程等与地下水变值系统理论相结合进行地表水地下水或多水源的联合优化调度，使模型更准确、更实用；⑥对保证地下水资源可持续开发的内部条件和外部条件进行了分析，内部条件主要是正确的资源观，科学的资源计算与评价方法，可靠的资源预测预报技术，可操作的资源管理措施，外部条件主要是高层发展思路、管理体制的变革、配套的政策法规、经济杠杆的调节、人文素质的提高、节水意识的增强及具体节水措施、人口增长的控制、水体污染的防治、生态的恢复和重建等；⑦从宇宙科学、地球系统科学及哲学的高度审视地下水资源的可持续开发；⑧指出了地下水资源可持续开发的进一步研究方向。

This thesis is divided into six parts. The first chapter is preface, the current status of research in the inverse problems for parabolic partial differential equations is reported; the second chapter is "regularization methods for numerical differentiation and their applications ", in this chapter we investigate many regularization methods from a viewpoint of regularization theory and algorithm, some applications in the inverse problems for parabolic partial differential equations are given; the third chapter is "spectral regularization methods". Based on Fourier analysis, within the framework of regularization theory, we apply the spectral methods to some ill-posed problems. Many numerical experiments are done in order to show the validity of the methods; the fourth chapter is devoted to wavelet dual least squares method and a revised wavelet method; in the fifth chapter,we combine finite difference method with method of lines and apply it to the backward heat conduction problem in time; in the sixth chapter "identification problems for unknown source ", the essence and the degree of two problems related to source identification are pointed out, at the same time, some numerical methods are reported.

本文分为六个部分，第一章前言简要分析了国内外抛物型偏微分方程反问题的研究现状；第二章数值微分的正则化及其应用从正则化理论和算法的角度出发，考察了许多正则化方法，还给出了数值微分在抛物型偏微分方程反问题的一些应用；第三章谱正则化方法是在Fourier分析的基础上，在一般正则化理论的框架下，给出了这种方法在各种不适定问题中的应用，数值实验表明谱方法是有效的；第四章研究了小波对偶最小二乘方法和改进的小波方法；第五章主要研究了有限差分方法结合线方法在时间反向热传导问题中的应用；第六章是未知源识别问题，主要指出了两类未知源问题的不适定程度和不适定本质，同时报告了一些数值方法。

Based on consider hereinbefore, this dissertation discusses several aspects on the problem of the sustainable and optimum exploitation of groundwater resources as follows:①reviewed entirely the origin and evolvement of the concept "sustainable development", stated and commented the study status in queue on"sustainable development"around national and international range, thorough discussed the science connotation about the concept "sustainable development";②looked back and commented across-the aboard some furthest basic concept and proposition related to groundwater resources, put forward self opinions on a few existent mistake points of view and chaos understandings;③expatiated entirely on the content and meaning of the theory of changeable groundwater resources system, contrast with the traditional methods of groundwater resources calculation and evaluation, combined example to show the application of this theory;④thorough analyzed the difficult and complexity to forecast the groundwater resources, fully stated the traditional methods of groundwater resources forecasting, pointed out the characteristic and applying condition of these forecasting method, introduced the main ideas and methods of wavelet analysis developed recently, and the MATLAB software be known as the fifths era computer language, and its accessory wavelet analysis toolbox, applied these methods and tools to analyze the groundwater dynamic curve, adopted the B-J method and Morte-Carlo method, combined with the theory of changeable groundwater resources system, discussed the new view on the forecast of groundwater resources;⑤synthetically analyzed the characteristics and limitations of the present all kind of groundwater manage model, combined mathematical programming, mathematical statistics, random process and the theory of variation system of groundwater resources on the unite optimum attempter of surface water and groundwater, emphasized how to make the model more nicety, more simple, more practicality;⑥analyzed the inside condition and outside condition to assure the sustainable and optimum exploitation of groundwater resources, the inside conditions are the follows: correct resources idea, scientific methods of resources calculation and evaluation, credible forecast methods of resources, exercisable measures of resources management, the outside conditions are the follows: the development idea of high layer, the transform of manage system, the matched policy and rule of law, the adjusted of economy lever, the improve of cultural diathesis, the boosting up of water-saving consciousness and detail measures, the control of population rising, the prevention and cure of water pollute, the renew and rebuild of ecology;⑦scan the sustainable and optimum exploitation of groundwater resources from the high level of metagalaxy, earth system science, and philosophy;⑧point out the more directions on groundwater resources.

它将为制定水资源的可持续发展目标和战略决策提供科学依据，为制定社会、经济可持续发展战略提供理论基础。基于以上考虑，论文主要从以下几方面对地下水资源可持续开发问题进行了比较深入的探讨：①全面回顾了&可持续发展&概念的由来与演变，对国内外&可持续发展&的研究现状进行了述评，并对&可持续发展&概念的科学内涵进行了深入探讨；②对涉及地下水资源的一些最基本的概念和命题进行了全面的回顾和评述，对目前仍然存在的一些错误观点和混乱认识提出了自己的见解；③全面阐述了地下水资源变值系统理论的内容和意义，并与传统的地下水资源计算评价方法进行了对比分析，结合实例具体说明了方法的应用；④深入分析了地下水资源预测预报工作的极端重要性和复杂性，对传统的地下水资源动态预测方法进行了全面的评述，指出了各类预测预报方法的特点及适用条件，对最近二十多年刚发展起来的小波分析技术的主要思想和方法及其应用范围，以及号称第五代计算机语言的MATLAB软件和附带的小波分析工具箱进行了介绍，并应用于地下水动态过程线的分析，采用时间序列中的B-J法，蒙特卡罗方法，与地下水资源变值系统理论相结合，探讨了地下水动态资料分析和地下水资源预测预报的新思路；⑤综合分析了现今各类地下水管理模型的特点及缺陷，将数学规划、数理统计、随机过程等与地下水变值系统理论相结合进行地表水地下水或多水源的联合优化调度，使模型更准确、更实用；⑥对保证地下水资源可持续开发的内部条件和外部条件进行了分析，内部条件主要是正确的资源观，科学的资源计算与评价方法，可靠的资源预测预报技术，可操作的资源管理措施，外部条件主要是高层发展思路、管理体制的变革、配套的政策法规、经济杠杆的调节、人文素质的提高、节水意识的增强及具体节水措施、人口增长的控制、水体污染的防治、生态的恢复和重建等；⑦从宇宙科学、地球系统科学及哲学的高度审视地下水资源的可持续开发；⑧指出了地下水资源可持续开发的进一步研究方向。

Firstly, based on the analyzing the problems of the existing C~4ISR system architecture verification methods, the C~4ISR system architecture verification methods based on CADM is present, and the conception of this methods is given. Secondly, the basic connotation of this methods is studied form the views of the theory base and main superiority. Thirdly, the architecture information model is established, and based on this model the content framework of the C~4ISR system architecture verification methods is present. Lastly, the key techniques needed to solve in the framework is discussed.2. The verification methods of data categoricalness based on CADM are studied.

首先在分析现有体系结构验证方法所存在问题的基础上，提出了基于CADM的C~4ISR系统体系结构验证方法，并对该方法的概念进行定义；其次从理论基础和主要优势两个角度研究了基于CADM的C~4ISR系统体系结构验证方法的基本内涵；再次建立了体系结构信息模型，并以此为基础提出了基于CADM体系结构验证的内容框架；最后提出并解释了基于CADM体系结构验证方法所要解决的关键技术，包括基于CADM的数据完备性验证方法、可达性验证方法、数据一致性验证方法、系统结构合理性验证方法和作战规则合理性验证方法等。

Methods: 1. Experimental laparoscopic liver resection: We selected pigs as experimental models aiming to approach human beings physiological and anatomical condition. After CO2 pneumoperitoneum was established, the ligaments around liver were dissociated. Livers were cut off by the methods such as clamp dissection, microwave tissue coagulator, ultrasound dissector, Ligsure dissection, hand-assisted, short abdominal incision laparoscopy-assisted, and Endo-GIA switcher. The operation time and bleeding volume were compared between different methods of laparoscopic liver resection. The advantages and limitations of different methods were summarized. 2. Clinical laparoscopic liver resection: 15 cases with tumors in segment V of anterior right lobe or segments II, III of left lateral lobe or segment IV of left internal lobe were selected in this study. The liver diseases included hepatocellular cancer, hepatic cavernous hemangioma and hepatic focal nodular hyperplasia. The ligaments around liver were dissociated after CO2 pneumoperitoneum established. Laparoscopic liver resection were carried out by some of the methods combined such as clamp dissection, microwave tissue coagulator, hand-assisted, short abdominal incision laparoscopy-assisted, ultrasound dissector, rotation and suction dissector.

1、实验性腹腔镜肝切除：以猪为实验动物，旨在接近人体的生理、解剖环境下进行实验，建立操作空间后游离肝脏周围韧带，采用钳夹分离切肝法、微波刀切肝法、超声刀切肝法、Ligsure切肝法、手辅助腹腔镜肝切除法、小切口腹腔镜辅助切肝法、Endo-GIA切肝法等方法实施腹腔镜下肝切除，比较不同切肝方法的手术时间、出血量，总结各种方法的优越性及其局限性。2、临床腹腔镜肝切除：选择肿瘤位于肝右前叶第Ⅴ段、肝左外叶第Ⅱ、Ⅲ段及左内叶第Ⅳ段的15例患者，病种包括原发性肝癌、肝海绵状血管瘤、肝脏局灶性增生，建立气腹后游离肝脏周围韧带，采用钳夹分离断肝、微波刀固化后断肝、手辅助腹腔镜肝切除、小切口腹腔镜辅助肝切除、超声刀断肝、旋吸断肝等多种方法分离切线肝组织，暴露管道结构，再采用高频电凝、钛夹夹闭、缝扎止血、止血纱布覆盖、氩气刀止血、生物胶止血、Endo-GIA处理等多种方法相结合处理肝断面，统计手术完成情况、手术时间、手术出血量、术后并发症及术后住院时间等，评价腹腔镜肝切除的可行性及安全性。

This paper quantitates financial risk by constituting the model of measurement financial risk. And the samples are from the public companies'merger and acquisition from 2002 to 2005, this paper demonstrates perfectly the influence of financial risk of acquisition companies from different payment methods. The result of test analysis shows: in one side, the theory of risk-return is unfit in China (by being educed conclusions by other students: different payment methods bring different return, then the author detrusions different payment methods bringing different financial risk, and being tested direct proportion each other); in the other side, this paper answers different payment methods bringing different degree financial risk of acquisition companies: the smallest financial risk from cash payment method, the mean from commingle payment method, the biggest from stock payment method, which can supply reference in the choice of rational companies between payment methods and financial risk .

通过建立企业财务风险度量模型，将企业财务风险量化，并以中国上市公司2002年—2005年间的并购案中所采用的支付方式为样本，对我国上市公司并购中不同支付方式对并购方财务风险的影响做一个较系统、完善的实证检验，一方面从理论上验证了风险-收益理论的在我国的不具有适用性（通过对前人研究结论：不同支付方式带来不同收益，进而反推不同支付方式带来不同的财务风险，验证得出二者成正比关系）；另一方面回答在我国目前市场条件下并购中的不同支付方式引起收购公司不同程度的财务风险，其中现金支付方式下给收购公司带来的财务风险最小；混合支付次之，股票支付方式下财务风险最大，能给企业在并购时选择支付方式与财务风险的最佳组合提供参考。

Furthermore, the first-order optimality condition and its equivalent reformulations for generalized semi-infinite max-min programming with a non-compact set are presented using the lower-Hadamard directional derivative and subdifferential.2. Chapter 3 studies the gradient-type methods for unconstrained optimization problems. Section 1 proposes a new class of three-term memory gradient methods. The global convergence property of the method is established. Furthermore, in order to improve the convergence property of the method, a new class of memory gradient projection methods is presented with the property that the whole sequence of iterates converges to a solution to the problem under the conditions such as pseudo-convexity and continuous differentiability of objective function. In section 2, two new classes of methods, called gradient-type method with perturbations and hybrid projection method with perturbations, are proposed. In these methods, non-monotone line search technique is employed, which makes them easily executed in computer.

第3章研究了无约束优化问题的梯度型算法，第1节提出了一类新的三项记忆梯度算法，讨论了算法的全局收敛性，进一步提出了一类新的具有更好收敛性质的记忆梯度投影算法，并证明了该算法在函数伪凸的情况下具有整体收敛性，第2节在非单调步长搜索下提出了带扰动项的梯度型算法及其混合投影算法，这两类算法的一个重要特征就是步长采用线搜索确定而不象许多文献中那样要求步长趋于零，这样更容易在计算机上实现，在较弱的条件下证明了这些算法的全局收敛性，数值算例表明了算法的有效性。

In order to reasonably depict four basic problems with friction, one Coulomb friction new form in first Kirchhoff stress is proposed to deal with finite deformation problems, other Coulomb friction form in incremental mode to elastoplastic flow theory; Hilbert function spaces concerning elastoplastical problems with friction are established, so it makes all operations and calculations in the treatise standardized within the scope of reasonably topologic structure; In view of functional extremum, the equivalence between generalized variational inequalities principles in elastoplasticity with friction and corresponding basic problems are testified by inducing Lagrangian multipliers, so it provides a rationally theoretical basis for numerical methods in elastoplasticity with friction; From the viewpoint of variational inequality, the theory of generalized variational inequalities in elasticity and elastoplasticity with frictional constraint is studied, and the uniqueness and existence of the solution of FEM is proofed under the proposed conditions of stress compatibility, and them FEM approximation and a discrete solution are discussed; Based on the principles of generalized variational inequalities in elastoplasticity with friction, direct generalized variational inequalities methods is pretended, which is a natural generalization and development of direct variational methods; Using generalized variational inequalities methods, some examples in metal forming including plane deformation, upset and extrusion are analyzed and the results prove that all the theories and methods in the paper are right, feasible, accurate and advanced.

主要内容有：为了合理地描述金属塑性成形中摩擦约束弹性、弹塑性基本问题，提出和研究了有限变形下以Kirchhoff第一应力表示的Coulomb摩擦定律形式和弹塑性流动理论下以增量形式表示的Coulomb摩擦定律表示形式；系统建立了摩擦约束弹塑性问题的Hilbert函数空间，使本文规范在一个具有合理的代数拓扑结构内进行一切操作和运算；利用Lagrange乘子，从泛函极值的角度系统地阐述和论证了一系列摩擦约束弹性、弹塑性广义变分不等原理与相应的实际问题之间的等价性，它为处理摩擦约束的弹塑性力学数值方法提供了合理的理论基础；从变分不等式的角度出发，阐述了对应于摩擦约束弹性、弹塑性问题的广义变分不等式理论，首次提出了在应力相容性条件下，它的有限元解具有存在唯一性，进而讨论了其有限元近似及离散解法；基于摩擦约束弹塑性广义变分不等式原理，首次提出了直接广义变分不等式方法，这一方法是直接变分法的合理推广和发展；利用直接广义变分不等式方法对金属压力加工中的平面变形问题、镦粗、挤压等塑性成形问题进行了分析计算，验证了该理论和数值算法的正确性、实用性、精确性和优越性。

The dissecting of samples in group2 were difficult. The root of pulmonary artery and ascending aorta failed to be unfolded because fibrous tissue was tough, right and left fibrous trigone were too firm to be solved by hand. Cardiac muscle fibers couldn't be stripped along myofibrillar trajectory since they were prone to break because of their friability.

组2的心脏解剖困难，表现为纤维组织坚韧，游离肺动脉非常困难；徒手无法松解左、右纤维三角，肺动脉和主动脉根部的游离非常困难；心肌纤维坚硬、质脆，解剖时容易断离成碎块，无法沿纤维走行方向剥离。

We have battled against the odds in a province that has become increasingly violent.

我们对在一个争夺日益激烈省的可能性。