查询词典 model theory

Fourthly, this paper constructs a dynamic model of the choice between fixed-price offerings and auctions in EPOs in China, in the basic of the incomplete information game theory. The model discusses the total revenue of new issuer from IPO and SEO, bidding strategies and payoff of investors, the choice of selling method.

本文将招股机制主要分为固定价格发行（将累计投标询价方式纳入固定价格发行范畴）和竞价发行两种方式，以发行人联合收益最大化为分析框架，建立模型，在两种招股机制下分别考察发行人的联合收益、投资者的申购策略和申购效用、发行中的抑价等，论证发行人对招股机制的选择。

The vapour and plasma ignition times of the target are got based on the equation of heat conduction and cascade model. We suppose that the plasma is ignited when 210 generations of new electrons are born in vapour generation time. The influence of temperature on the thermodynamics and optics parameters of material also have been considered in the model. The resulting theory has good agreement with the experiment and overseas report. A blade method to measure the laser spot is given in this paper with validation and error analysis. The plasma threshold of metals in atmosphere and water ambients both are diagnosed with the light deflection and piezoelectric transducer. A Q-switched pulsed Nd:YAG laser operating at infrared (1064nm), visible(532nm) and ultraviolet (355nm) wavelengths has been used. Al、Fe、Cu are used as targets and get a similar results with both method. Theoretical and experimental analyses are applied on the influence of wavelength on the threshold have been done, both of which have shown that the plasma threshold of metals decrease as the laser wavelength increases; The plasma threshold of metals are higher in water than in air and the pressure of the shock wave in water is five times higher than in air.

从热传导方程和雪崩电离机制出发，假设当电子增值2~(10)倍时，考虑了温度对材料热力学和光学参数的影响时，得到了气化和等离子体点燃的时间，利用该模型进行计算得到的结果与国内外报道及自行通过实验测得的阈值基本一致；提出了利用刀刃法测量激光光斑面积的方法，并通过实验进行了验证和误差分析；利用光偏转装置和压电换能器分别对空气和水中金属等离子体点燃阈值进行了实验诊断，激光器均为调Q—YAG激光器(波长1064nm，532nm，355nm，脉宽10ns)，靶材分别为Al、Fe和Cu，两种测试方法得到的等离子体点燃阈值基本一致；本文从实验和理论计算两个方面讨论了波长对等离子体点燃阈值的影响，均得到了等离子体点燃阈值随着波长的增加而减小的结论；对空气中和水中不同环境下金属等离子体的点燃阈值进行了比较研究，得到了金属在水中的等离子体点燃阈值比空气中的大，且水中产生的冲击波的压强是空气中的5倍左右的结论。

It anlysises the connotation and the cause of the ecological risk. Based the research about ecological risk theory, the model of EVR has been established with use of VaR which is a very popular risk man agement model in international market.

系统探讨了生态风险的成因、内涵；结合当前国际上流行的VaR风险管理模型，在生态风险理论有关研究的基础上，建立了一类新颖而实用的区域生态系统风险管理模型－EVR。

In order to find out completely the soil-wheat contaiminated by heavy metals in Tianjin sewage farm, we collect samples on the dry land and examinate contents of heavy metals in soil-wheat system. Firstly, the anthor evaluates that soil irrigated by sewage that has been contaminated slightly, the main polluting factors are Cd and Zn, and then the anthor evaluates soil according to different regions, soil types and irrigating water. Secondly, the anthor analyzes content and enrichment ability of heavy metals in different part of wheat, evaluates wheat is contaiminated by Cd widespreadly, only few samples polluted by Zn.Finally the anthor put up correlative analysis about heavy metal contents in the soil-wheat system, as well as plant enrichment coefficient and some physico-chemical properties of soil, and establishes a prognostic model about heavy metal content among wheat spike, soil, soil types, PH, organic matter and salinity with the quantifying theory.The prognostic accuracy of primarily contaminative factors is the best with compound correlative coefficient examining, the model can be founded.With improvement of living level, people need cleaner food.

为全面了解天津市污灌区农产品生产地土壤和旱地作物小麦的重金属污染状况，我们于2004～2005年对全市污灌区的土壤和小麦进行了采样，在对该区土壤—小麦系统中六种重金属元素(Cd、Cu、Pb、Zn、Cr和Ni)的含量进行检测的基础上，本文首先分析评价了污灌区农田土壤的环境质量总体已达到了轻度污染水平，主要的污染因子是Cd和Zn，同时对污灌区农田土壤分区县、土壤类型和不同灌水类型进行了评价；然后分析了重金属在小麦不同部位的含量与富集能力，评价了污灌区旱地作物小麦普遍遭受了Cd的污染，只有个别样点遭受了Zn的污染；最后对土壤—小麦系统重金属含量间以及植物富集系数与土壤部分理化性质间进行了相关分析，由于土壤类型是定性变量，本论文以数量化理论建立了小麦穗实中重金属含量与土壤中重金属全量、土壤类型、PH值、有机质和全盐量间的预测模型，经复相关系数检验，污灌区主要的污染因子Cd和Zn的预测精度最高，模型可以成立。

Based on the theory of tidal flow and sediment motion, a 2-D depth-integrated mathematical model for the Jiaojiang Estuary is developed by using explicit scheme of finite difference on the triangle elements. The results show that the rotary currents occurring in this area can be simply and effectively simulated by the model. Meanwhile, the suspended sediment concentration simulated is in agreement with the field data.

本文根据椒江口实测水文地形资料，从平面二维水流泥沙基本方程和基本理论出发，采用三角单元有限差分法对水流泥沙方程显示求解，对椒江口潮流泥沙进行了数值模拟，模型简单实用，较好地再现了具有旋转潮波性质的椒江河口水流运动特征，含沙量场也得到了基本正确的反映。

Calculations by using in -house model, field model experiment, and various models prove the correctness of this theory.

室内和野外模型实验以及不同模型的正演计算，证明了极化理论的正确性。

Papers analyzed the management flexibility and value of mining engineering, and set up the model of value of a developed mine,value of an undeveloped mine and value of an exploration project under the conditions of uncertainty with the theory of real option,and worked out the solution of model above-mentioned through three numerical methods,i.e.the Fig Tree,finite difference approximation and Monte Carlo simulation.

论文最后研究了矿业工程中的管理灵活性及其价值，运用实物期权方法分别建立了不确定条件下矿业生产阶段、开发阶段和详查、普查、预查阶段的矿业投资评价模型，并运用二叉树图、有限差分逼近和Monte Carlo模拟三种数值方法对所建模型进行了求解，同时通过实例对论文的研究结果进行了佐证。

The mathematics model of three-dimension temperature field of the machine tool spindle system is created, and based on elastic mechanics, basic equation of heat deformation and finite element theory, the mathematics model of heat deformation is built.

建立了机床主轴系统三维温度场数学模型，并基于弹性力学、热变形基本方程和有限元理论建立了热变形的数学模型。

Man-in-the-loop simulation is a promising branch of simulation field. This paper presented the theory on man-machine engineering, and established the model of the firer of antitank missile. Then a test software was introduced to identify the characteristic parameters of human. Finally, we performed digital simulation on the missile system including the firer model and used the TIC unequal coefficient method and gray relating method to analysis the simulation results.

摘 要：该文介绍了人机工程中关于对人体建模的理论基础，并在此基础上建立了反坦克导弹射手模型；为确定人的典型特性参数，编制了一套小型测试软件，利用这套软件可以初步辨识出被测人员的特性参数；最后对含有射手的导弹武器系统进行了数字仿真，并用TIC不等式法及灰色关联分析法对仿真结果进行了精度分析。

First, a mathematic model for laser diode with a cool is established, which is looked as a first order segment of inertia in theory. It analyzes the step response in the S field and the time field separately after adopting PID control technique, and it also analyzes the equivalent noise model of the amplifying circuit.

首先从理论上对带制冷的半导体激光器组件建立了数学模型，将其看作一阶惯性环节，分别在S域和时域里详细分析了采用PID控制技术后的阶跃响应；同时也对光接收机放大电路等效噪声模型进行分析。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。