面积函数

The critical nitrogen content in heading period was used to calculate the biggest accumulation quantity of nitrogen. The latent distribution index of leaf and stem, which was the variety heredity parameter, were used to distinguish the difference in nitrogen assignment in different varieties. The dynamic content of the nitrogen accumulation before anthesis could be described with a Richards model. The dynamic content of the nitrogen remobilization in leaf with leaf area index could be described with a power model, and the nitrogen absorption of grain from soil with dry weight could be described with a power model. The dynamic content of nitrogen density in stem and spike with physiological development time could be described with a nonlinear model.

模型利用抽穗期植株临界含氮量来表达氮素最大积累量，引入叶片潜在分配指数和茎鞘潜在分配指数2个品种遗传参数来区别不同品种在器官间的氮素分配差异，采用Richards方程来描述大麦花前氮素积累动态变化；采用指数函数方程来描述叶片氮的转移量随叶面积指数的动态变化以及籽粒从土壤中吸收的氮量随干物重的动态变化；采用非线性函数方程描述茎鞘和穗部的氮浓度随生理发育时间的动态变化。

The result pointed out that the vertical distribution of foliage for each species was different,however,generally speaking,the foliage in upper crown (0.3CL) for broad-leaved species in natural secondary forest took a small percentage,about 10%;in middle or middle lower of the crown(0.4CL to 0.8CL) the branches here took the majority percentage of whole foliage,almost 60%to 75%;but in lower crown(0.8CL),there was about 10%of whole foliage.(5)The interspecies competition of trees in secondary forest was expressed by Hegyi competitioin index,and the active competitor was calculated by the competition zone radius and the tree position,DBH,and distance in the zone,it was not all competitors in tranditional calculation.The study introduced crown area overlap index to describe the crown competition between subject tree and its competitors,furthermore,the crown area was classified into 5 levels with a method of equal crown projection area,therefor,the resulting crown area overlap index showed more realities of existing stand conditons.(6)Based on the theoretics of multiply divide,the spatial strcture optimizing model of secondary forest stand selective thinning was developed by diversity mingling,aggregation index,competition index and crown area overlap index,also designed 10 constraint conditions which were related to forestry meanings,the objective function was solved by the implicit enumeration method with LINGO 9.0,using 0-1 integer programming.

并且得出，每个树种在树冠内相对高度上的叶量的垂直分布是不同的，天然次生林阔叶树种的叶量在树冠的上部(0.3CL以下)所占比例很小，约占10%左右；在树冠的中部以及中下部(0.4CL～0.8CL)，叶量所占比例最大，几乎集中了整个树冠60%～75%的叶量；而在树冠的下部(0.8CL以下)，几乎占很少的叶量，大约10%左右。5、采用Hegyi竞争指数来表现次生林内林木的竞争关系，并且根据竞争圈的大小和林木在竞争圈内的分布位置、大小与距离来计算有效的竞争木，并不是传统意义上的全部竞争木；本研究提出用树冠叠加指数来表示林木与周围树木的树冠竞争情况，并采用等树冠投影面积法把树冠分为5级，这样计算的树冠叠加指数更加与现实林分相符。6、本研究基于乘除法的思想，用多样性混交度、聚集指数、竞争指数和树冠叠加指数构建了天然次生林择伐空间优化模型，设计了10个与林学意义相一致的约束条件，并采用0-1整数规划的思路，在LINGO9.0软件中使用了隐枚举法对目标函数求得最优解。7、以M702标准地为应用实例，具体计算出了每株采伐木，经过择伐后，目标函数值按模型设计的要求发生了极大的改变，增加了5倍多，说明了最后这个解的优良性，满足了设计的要求。

There are many methods for computation of the slope and deflection of beams such as the integration method, the finite difference method, the Macaulay's method, the Mohr's 'area-moment' method and so on. They possess mostly the characteristics of complex computing or searching schematics.

有多种方法求梁的位移，如积分法、迭加法、初参数方程法、其轭梁法、有限差分法、奇异函数法和莫尔&面积一力矩&法等等，其大都具有或计算复杂或依赖各种不同的图表等特点。

The volume of a cylinder is the area of the base, which is a circle (you already programmed this function in this chapter, so reuse it) multiplied by the height.

圆柱体的体积是圆形底的面积(你已经在这章编写了这个函数，所以重新利用它)乘以高。

These coefficients are given as the function of hull parameters, height of gravity and the area of bigle kells, etc.

这些计算式均以船型参数、重心高度以及舭龙骨面积等参数的函数形式表示。

In terms of each of these essentials, Lyapunov direct methods, transient energy function methods and extended equal-area criterion are critically compared in this four-part paper. This reveals the essence causes for why both Lyapunov direct methods and TEF methods cannot be applied to transient stability analysis of power systems.

由4篇短文组成的系列文章按照上述各要素，讨论了针对平衡点稳定性的李雅普诺夫法、将平衡点稳定性理论应用于有界稳定性的暂态能量函数法以及针对有界稳定性的扩展等面积准则这3种稳定性理论在大扰动稳定性分析中的应用。

The vertical distribution of Aeolian sand current Based on the distribution function of lift-off velocity of saltating sand grain, this thesis develops a vertical distribution model of Aeolian flow linking with the number of lift-off sand grains percent time percent sand area. The thesis realizes the combination of microcosmic researches and macroscopical researches of Aeolian wind sand and solves primarily the isjunction of microcosmic researches and macroscopical researches.

4风沙流的垂向分布以本文获得的沙粒起跳初速度分布函数为纽带，结合本文获得的单位时间单位面积沙床起跳沙粒数，建立风沙流的垂向分布模型，实现风沙运动宏观研究和微观研究相结合，初步解决长期以来宏观与微观研究相脱节问题。

The boundary shape and length of fire zone are growth with time, which determine the fire HRR is variational with time and space distribution.

火场边界形状长度和火场面积随时间而变化发展，决定了火灾释热率在时间和空间分布上都是变化的函数，火灾HRR不同于稳态火和T〓火。

According to thefunction, the conclusions for L.olgensis and C.lanceolata are asfollows:1CCF＜200,showing growth with constant tree number;2200≤CCF≤300 transition from growth with constant tree number to theself-thinning,in other words,the change of SDI can be described aslinear combination between the growth with constant tree number andthe self-thinning;3CCF＞300,growth in the self-thinning.

建立了CCF与林分密度指数和单位面积林木株数之间的函数关系式，并对长白落叶松和杉木得出：(1)CCF＜200。林分为等株数生长：(2)200≤CCF≤300时。为等株数生长向自然稀疏生长的过渡期，该期间林分密度指数的变化可用等株数生长和自然稀疏生长的线性组合来表达：(3)CCF＞300时，林分为完全的自然稀疏生长

According to the fractal dimension, the disturbed distance between upper and lower fracture surfaces and the ratio of area contact (the proportion of contact area to whole area of fracture) of fracture, the random Brown Function is used to generate a rough-walled fracture with position-dependent aperture.

根据裂隙面分形维数、裂隙面位错值和裂隙面上的面积接触率，用随机布朗函数生成裂隙的开度分布。

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。