查询词典 distributions

While most people realise it is hard to calculate VAR using internal data alone (because of the small sample size), many are unaware that because op risk is characterised by fat-tailed distributions, even the expected loss cannot be estimated using just internal loss data.

虽然大多数人认识到单单使用内部数据很算计算出风险值，可很多人没认识到这一点：因为操作风险的特征是厚尾分布，要是单单使用内部损失数据，连预期损失都无法估计出来。

The main results were obtained as follows:(1) The calculation results of temperature field indicate that, 6139T radiator was brazed using the stage-by-stage heating process, while 6204T radiator with a larger size was brazed using the temperature difference heating process. The uniform temperature distributions in faying faces were all obtained. And the temperatures were in the range of brazing temperature. It is proved that the finite element models established are reasonable.

取得的主要结果和结论为：(1)温度场计算结果表明，对于6139T散热器，采用分阶段加热钎焊工艺，而对于具有较大尺寸的6204T散热器，采用温差法加热钎焊工艺时，均获得了均匀的钎焊面温度分布，且在钎焊温度范围之内，证明所建立的有限元分析模型是合理的。

With this model, the deformation and stress distributions of the flange joint are analyzed using ANSYS FEM software, and the influences of gasket properties, tube side pressure and shell side pressure, bolt pr.

本论文以U形管换热器法兰夹管板接头为研究对象，考虑垫片材料压缩的非线性特性和压缩-回弹时的时滞效应，将法兰接头各元件看成一个系统，研究各元件的相互作用，建立了管板-法兰-垫片-螺栓连接系统的非线性三维有限元分析模型。

The distributions of velocity, velocity gradient, shear stress, clongation stress, first normal stress difference and pressure of the flow of a power-law fluid in the profile die were analyzed. It indicates that for a power-law fluid only after a few iterations a good convergence can be reached, even though in the case of high extrusion velocity.

详细分析了聚合物口模挤出三维计算机模拟研究中的若干关键技术问题，如对异型材结构特点的分析、边界条件的确定、初始速度场的自动生成、罚数的求取、粘弹性流动模拟中的高We数问题、三维挤出胀大的自由界面更新等。

The distributions of velocity, velocity gradient, shear stress, clongation stress, first normal stress difference and pressure of the flow of a power-law fluid in the profile die were analyzed. It indicates that for a power-law fluid only after a few iterations a good convergence can be reached, even though in the case of high extrusion velocity.

本文分析了幂律流体在异型材挤出口模内的速度分布、速度梯度分布、剪切应力分布、拉伸应力分布、第一法向应力差分布和压力场，研究表明采用幂律流体模型，即使在挤出速度非常大的情况下，经过有限次迭代，模拟计算都能够收敛，并得到合理的结果。

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory.

本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

In this dissertation the"Penalty"finite element method was employed to compute the velocity of the three-dimensional flow of power-law fluid in a profile die. In order to decrease the needed computer memory and raise the stability of numerical simulation, a set of decoupled methods such as PFEM, pseudo-body force method and transformation of momentum equation to the elliptic equation was developed to establish the general finite element equations to compute the distributions of velocity and viscoelastic stress of the three-dimensional viscoelastic flow of the Phan ThienTanner fluid in a profile die. During numerical simulation of the extrudate swell of the PTT fluid, the flow in the die and out of the die was analyzed separately, which demands less computer memory. The key techniques used in numerical simulation of the three-dimensional extrusion from dies such as decision of boundary conditions, creation of initial velocity field, selection of penalty factor, high Weissenberg number problem , regeneration of the free surface were studied in detail.

中文题名聚合物异型材口模挤出三维流动研究副题名外文题名 Study on three-dimensional flow of polymer melts during the process of profile extrusion from dies 论文作者涂志刚导师柳和生包忠诩教授学科专业材料加工工程研究领域\研究方向学位级别博士学位授予单位南昌大学学位授予日期2001 论文页码总数148页关键词挤出成型聚合物材料挤出口模聚合物异型材馆藏号BSLW /2003 /TQ320 /9 本文建立了求解挤出口模内幂律流体流动速度场的通用三维罚有限元模型；对于非线性粘弹性的Phan Thien-Tanner流体，为了降低模拟计算对计算机硬件的要求，并使模拟计算更加稳定，采用了一种去耦算法，包括罚有限元方法、拟体力方法和动量方程的椭圆类方程转化方法，并建立了求解速度场和粘弹性应力场的总体有限元方程；对于PTT流体的挤出胀大问题，提出了挤出胀大熔体口模内外分离模拟法，这样可以显著降低数值模拟对计算机硬件的要求。

Particles in the range of 10 to 150 microns fluidise best and careful selection of the size distributions used leads to higher efficiency.

粒径在10到150微米的颗粒都可以很好地流化，小心地选择粒度分布可以使效率更高。

Main contents of the course includes: related conceptions, matter of soil, soil texture, soil organic matter, soil humus, soil structure, soil moisture, soil air, soil acidity and soil alkalinity, soil colloid, cation exchange, soil former soil-forming process, soil classification, distributions and properties of soil great group in China (fores soil, steppe soil, main non-zonal soil, paddy soil, etc), soil erosion, soil contamination, soil utilization, conservation of soil resource, soil investigation, etc.

土壤地理学是地理科学专业的主要基础课程之一，是一门必修课程；要求掌握土壤地理学基本的理论、知识和方法；主要内容有：有关概念、土壤组成物质、土壤质地、土壤有机质、土壤腐殖质、土壤结构、土壤水分、土壤空气、土壤酸碱性、土壤胶体、土壤阳离子交换、土壤形成因素、土壤形成过程、土壤分类、中国主要土壤类型（森林土壤、草原土壤、主要的非地带性土壤、水稻土等）的分布及其性质、土壤侵蚀、土壤污染、土壤资源的利用与保护、土壤调查研究等。

Based on the experiment, the relationship between phase distributions of diffusion triples and four-phase equilibrium can be determined.

在Nb-Ti-Si三元系1473K、1373K、1173K等温截面测定的实验中，发现了该体系在1473K附近存在一个包共析转变，并由此得出包共析转变与扩散偶中相区分布的关系。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。