三次方程

Therefore at each time we get the roots of this cubic equation, we can decide if we keep or reject each root according to the continuity of the curved surface, the method is as follows: If , the relative cubic plane curve is just a circle, this circle can be gotten by solving .

因此在每次求得该一元三次方程的解时，我们根据曲面的连续性来判断这些根的取舍，方法如下：在处，所得的平面曲线就是圆截线，该圆截线可以由相截得到，即。

Throush the interlace series type linear differential equation,coefficient containing three negative number of times,power function and arrangement number can be changed into the linear differential equation of successive integral.

通过把系数含有负三次幂函数与排列数的交错级数型线性微分方程化为可逐次积分的线性微分方程，找出了求这类方程通解的方法与理论，把所得定理给出了严格的证明，并将其推广，同时通过实例介绍了它的应用。

Under the fixed and clamped boundary conditions, a nonlinear differential oscillation equation with quadric and cubic items was presented by the Galerkin method, and a nonlinear free oscillation equation of the shallow reticulated shells with damage was solved.

基于Lematire等效应变损伤原理，计及扁球面网壳各个杆件的损伤影响，根据薄壳非线性动力学理论推导出含有损伤扁球面网壳非线性动力学方程和协调方程，在固定夹紧边界条件下，用Galerkin方法得到一个含二次和三次非线性振动微分方程，并对具有损伤扁球面网壳的非线性自由振动方程求解。

Through analyses, we can make the conclusion that, the relation of seed fresh weight dry weight and days after pollination, fat percent content, protein nut content, starch nut content can be expressed with Logistic equation; the change of kernel volume, moisture content of kernel and days after pollination accorded with three ascend curve equation. Kernel protein content, starch content and the changes of days after pollination tallied with reciprocal equation and they had high relation.

经过统计与分析，可以看出籽粒鲜重积累量与授粉后时间、籽粒干重与授粉后的时间、脂肪净含量、脂肪百分含量、蛋白质净含量、淀粉净含量与授粉后的时间均可以用Logistic方程描述，籽粒体积变化与授粉后的时间关系表现为三次上升型曲线方程；籽粒的水分含量与授粉后的时间关系表现为三次下降型曲线方程；籽粒中蛋白质百分含量与授粉后时间的动态变化规律、籽粒中淀粉百分含量与授粉后时间的动态变化规律符合倒数方程，均具有较高的拟合度。

The influences of different kinds of conducting materials and their contents and different volume of PVC grain on the electrical property,mechanical properties and terrazzo lines of the floor were studied.

采用特殊成型方法，研制类似网络结构的水磨石形式的抗静电地板，研究了多种导电材料及其不同用量对网络地板导电性能、力学性能和地板纹路的影响；研究了PVC颗粒大小对地板的导电性能、力学性能和地板纹路的影响；对体积电阻率曲线用三次方程进行了拟合，得到体积电阻率与含量的函数关系，并发现其具有很好的相关性。

The purpose of this chapter is to present a very straight forward approach and indicate the utility, advantages and power of using the combinations of the linear transformation approach and the trigonometric solution for the cubic equation to obtain a general closed-form analytic solution for bulk waves in orthotropic anisotropic materials.

目的是综合应用线性变换与一元三次方程的求解技术得到正交各向异性材料中平面体波的严格解析解。

The fitting method of dynamics processes of removing main nutrient TP by Lolium multiflorum showed that it accords with cubic curve.

对其去除水体总磷的动态过程拟合表明符合三次方程曲线。

The second, according to mapping function of blank and product sections, and to many interpolating functions along model-cavity vertical surface, paper has built mathematics model, fluid surface function of special-shaped product plastic deformation and velocity field, gotten basis theory for metal forming prediction, for example empty drawing metal pipe thickness homogeneity and special-shaped product fluid regular, die parameter optimization and integration research of die CAD/CAM.

根据拔制坯料和制品截面映射函数和模腔纵向多种插值函数（直线型、凸型、凹型和三次多项式型），建立了相似异型材、圆形坯料——异型材和异型材——异型材三维金属拔制塑性成形的数学模型和异型材塑性成形的流面方程及流动场方程，为预报金属成形规律（如：空拔管壁均化、异型材流动规律），模腔参数优化及其CAD／CAM一体化研究提供了理论基础。

This solution was expressed a function of offset, compressional and shear waves velocities, the traveltime of P-SV converted waves.

Schneider（2002）从一个关于转换点的三次方程中推导出了P-SV转换波转换点位置的一种解析解，这种解是偏移距、横纵波速度和P-SV转换波旅行时的函数。

In certain range,the bioenrichment of the mealworm larvae to Zinc in reference to the dosage added in the fodder is accorded with cubic curve relation:Y=181.2517+20.9314X-0.4099X2+ 0.0025X3. And the enrichment ability of T. molitor larvae in reference to the weight is also accorded with the cubic model:Y=35.8325+61.4155X-10.2980X2+0.4434X3. The enrichment of the larvae to Zinc can get to a high level in 2 to 3 days. This is anadvantage to numerous rearing of the mealworm. But we do not find a good rearing way to enhance the rate of bioenrichment to Zinc. And the further research about this is anticipated.

第二部分：采用锌作为添加元素，考查黄粉虫对微量元素的富集规律，结果表明：(1)黄粉虫虫体锌含量在一定范围内随锌添加量增加而呈三次曲线关系，符合三次曲线方程：Y=181.2517+20.9314X-0.4099X~2+0.0025X~3；(2)黄粉虫幼虫对锌富集能力随虫体大小变化而变化，与虫大小亦呈三次曲线关系；Y=35.8325+61.4155X-10.2980X~2+0.4434X~3；(3)黄粉虫虫体锌含量随着锌饲料添加而迅速上升，可在短期2～3天内达到较高水平，对于以黄粉虫为材料进行富锌保健食品生产有很大优越性；(4)本试验并未找到一种较好的锌添加方法来提高锌富集量，这方面的研究有待继续。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。