不存在

In order to research its natural circulation, the downcomer part and the riser part is distinguished, where there are no mass and energy transferred between them.

该模型为体现其自然循环的特性，将下降段与上升段区分开，并假定两者之间不存在质量和能量的交换。

The sufficient condition for nonexistence of the closed orbit is got by using the method of Dulac function.

运用Dulac函数法，得到了系统不存在闭轨的充分条件。

The sufficient condition for the inexistence of limit cycle is found using the method of Dulac function.

运用Dulac函数法，得到了系统不存在极限环的充分条件。

It is proved that there is no limit cycle around the positive equilibra by constructing Dulac function, thus global asymptotic stability of the positive equilibria is proved in the first quadrant.

分析了该系统的平衡点性态，利用Dulac函数证明了系统在正平衡点外围不存在极限环，从而证明了正平衡点在第一象限内是全局渐近稳定的。

In this paper, the nonexistence of the closed orbit which circles the equilibrium is proved by using the Dulac function, then all the orbits of the system are bounded by the Filippov transformation and comparability theorem.

本文利用Dulac函数法，首先判定了不存在绕平衡点的闭轨线，然后利用Filippov变换和比较定理，证明了系统所有轨线的有界性，进而得到了平衡点是全局渐近稳定的。

When the value of critical threshold larger than 1, the disease and insect pests equilibrium point is locally asymptotically stable An appropriate Dulac function should be choosed and Bendixson-Dulac creterion is used to prove that the limit cycle in this model does not exist. It explains that the disease and insect pests equilibrium point is globally asymptotically stable.

选取适当的Dulac函数，利用Bendixson-Dulac判别法证明了极限环的不存在性，说明局部渐近稳定的病虫害平衡点也全局渐近稳定。

Indentor and the applied force influence the measurements such that no simple relationship exists between the measure-ments obtained with one type of durometer and those obtained with another type of durometer or other instruments used for measuring hardness.

压足的几何形状和施加力对测量的结果有影响，不同类型的硬度计和测量仪器测出的硬度值之间的不存在简单的关系。

Product description: ZT4-00 23 liters laboratory beater Characteristic: This machine adopts Holland type beater chest, beater roll, bed knife which all used high-quality stainless steel; beater roll is made of stainless steel, knife can't be drop. Long performance life; automatically beat time control; dustcoat used organic material transparent high strength, whole operating process is directly observed.

产品说明： ZT4-00型23升打浆机特点：本机采用荷兰式浆池、飞刀辊、底刀并全部采用优质不锈钢制作；其中飞刀辊是整体不锈钢制作，不存在刀片松动等现象，使用寿命长；打浆时间自动控制；外罩采用透明高强度有机材料制作，整个操作过程直观可视。

Edmund: It doesn't exist.

爱德蒙：它根本不存在。

The title accurately reflects the eeriness of the giant solid form, which appears like a mausoleum representing and containing something that no longer exists.

这个题目也明确的表达了这个巨型固体的阴森，像个表现那些不存在事物的陵墓。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。