有环的

Using qualitative analysis methods, the paper studies the boundedness of solutions and the existence of limit cycles.

利用定性分析的方法，讨论了模型在收获率条件下平衡点的稳定性，解的有界性，极限环的存在性问题。

The most important idea is that over the complex numbers, an elliptic curve looks like a torus, and the points of finite order in the group of the curve have a very simple geometric description.

最重要的思想是复数域上的椭圆曲线是一个环面，曲线簇中的有限阶点有简单的几何描述。

The results of electron affinity and ionization potential show that theelectron transfer properties of quinone are enhanced with the enlongation of thesubstituent.

电子亲和势和电离势的研究结果表明，随着醌环上异戊烯支链的增长，醌的电子传递能力有增强的趋势。

The conveyors in this group are driven by a powered chain or cable that forms an endless loop.

在这一个小组的运送装置被被链有力量的或者形成一个永无止境的环的电缆驱使。

But if there is more than quarter of negative growth ring, you need to bank the future development of a very cautious approach.

但是，如果有比出现负增长，环的四分之一以上，则需要银行的一个非常谨慎的态度的未来发展。

According to the construction features of β- cyclodextrin, a comparison analysis is made between fragrance inclusion of BCD and mono - molecules of fragrance.

根据β-环糊精的结构特点，对BCD的香料包给物和香料单体分子进行了对比研究，证明BCD与客体形成的是单分子包结物，该包结物在热稳定性、抗氧化性方面优于客体分子，有相当的实际应用价值。

The necessary and sufficient condition for that the problem P〓 is nonsingular is derived.

利用原问题与P〓的等价性，给出了原系统二次指标最优控制器的设计，保证了闭环对给定的初值有唯一的光滑轨线且零解渐近稳定。

In these bicyclic sesquiterpanes,the relative abundance of the rearranged drimane is regularly changed in spatial distribution,which may indicate the characteristics of petroleum migration and accumulation in QHD32-6 oilfield.

该油田双环倍半萜中重排补身烷的相对丰度在纵向上和横向上都表现出有规律的变化，这种规律性的变化可能反映了秦皇岛32-6油田油气运移与聚集的特征。

In cross-sectioned root form 2 middle bark layer next Internal bark layer especial structure of regularly array; epidermis cell of stems and leaves have developed thickened epiderm, leaves epidermis covers hair, it formed developed vascular bundles.(4)Chromosomes of Agropyron cristatum is tetraploid .

根横切面上形成了在紧靠内皮层的两层中皮层细胞有规则整齐排列成两环的特殊结构；茎和叶表皮细胞均具有发达的角质层，叶表皮多密被毛，其形成了发达的维管束及维管束鞘。

More interestingly, these two types of oscillations ...

更有意义的是，这两种类型的电化学振荡分别与循环伏安图中的两个交叉环相对应。

Finally, according to market conditions and market products this article paper analyzes the trends in the development of camera technology, and designs a color night vision camera.

最后根据市场情况和市面上产品的情况分析了摄像机技术的发展趋势，并设计了一款彩色夜视摄像机。

Only person height weeds and the fierce looks stone idles were there.

只有半人深的荒草和龇牙咧嘴的神像。