分支

The existence of saddle-node bifurcation, Hopf bifurcation and Bogdanov-Takens bifurcation is studied clearly, and high codimension bifurcation may emerge for some special parameters.

文中我们全面分析了鞍结分支、Hopf分支和Bogdanov-Takens分支在各种参数条件下的存在性，还发现在一定参数条件下可能出现高余维分支。

We study cuspidal loop bifurcation、 Homoclinic or double Homoclinic bifurcation、 Hopf bifurcation and obtain the necessary conditions to generate limit cycles by using the coefficients of the expansion of the first Melnikov function.

利用一阶Melnikov函数的展开式的系数研究了尖点环分支、同宿分支、双同宿分支和Hopf分支，并给出了产生极限环的充分条件。

In view of the rheological property of the heavy oil in Bo-hai field, this paper deduces the multilateral wells'production model of Non-Newtonian Bingham fluid with equiangular transformation method. In view of the multilateral wells Bo-hai, the paper analyses the multilateral wells'capitalized cost composition, including pre-drilling engineering, drilling engineering, completion engineering and production engineering. It also constructs the multilateral wells'economic benefit models basing on net present value, inner rate of return and payback period.

针对我国渤海油田稠油的流变特性，运用保角变换方法，推导了非牛顿Bingham流体的分支水平井产能模型；针对渤海油田的分支井，从钻前工程、钻井工程、完井工程、采油工程等方面对分支井的投资成本费用构成进行了具体分析；最后以净现值、内部收益率、投资回收期经济评价指标为基础，建立了海上分支井经济效益模型，并根据所建模型应用VB。

The effects of number and angle of lateral hole on the production of herringbone well were analyzed by this model.

利用该模型对鱼骨井的分支数、分支角度影响产能的分析结果表明，分支角度大于45°后鱼骨井总产能增加不大；分支数越多，对主井筒的影响越大。

Finally,the WISCONSIN Sequence Analysis Package (GCG,10.2 version),Phylogenetic Analysis Using Parsimony (PAUP,4.0 version) and Treeview (1.5 version) software were used for data analysis,sequence translation,phylogenetic tree drawing and molecular evolution analysis.

本研究结果证明，H9N2亚型人体分离株属于G1-like亚分支的G1-HK小分支，该小分支毒株之间具有很高的同源性，因此该小分支AIV可能具有感染人的可能性，是具有引起人流感暴发潜能的病毒。

Secondly, method of Taylor series is used to approximate the slow manifold and the O approximation of the slow manifold is given; slow dynamics such as saddle node bifurcation which has been proven to be the same as that for the full system is analyzed; at the same time, fast dynamics including bifurcation conditions and domain of attractor of the stable equilibrium are also analyzed; the attracting region which consists of the stable manifold of the unstable equilibrium and stable equilibrium is given; we found that when the inner flux decay increases, the domain of attractor is enlarged.

首先，给出了电力系统SMIB模型的时间尺度分解，得到标准的奇异摄动模型；其次，利用幂级数方法，给出了慢流形的O近似M〓，分析了在慢流形M〓上的慢动态，得到了慢子系统的鞍结分支值，并证明此分支值与原系统的鞍结分支值相同；分析了快子系统的平衡点和全局分支的存在条件，给出由不稳定平衡点的稳定流形与稳定平衡点形成的吸引域；并研究内部电压对稳定域的影响，发现稳定域随内部电压增加而扩大；最后给出整个系统的稳定平衡点的近似吸引域。

Results The segmental bronchial ramifications of the left upper lobe were classified into three types mainly: common stem of apical and posterior segmental bronchi (64%, 130/200), trifurcation (23%,45/200), common stem of apical and anterior segmental bronchi (10%, 21/200), and they could be identified in two typical slices of transverse thin-section CT.

左肺上叶3种主要分支类型可以通过薄层CT横断面图像2个典型层面辨认；左肺下叶依据基底干支气管分支的不同分为2种主要类型，Ⅰ型163例(75%)：基底干支气管两分支，即内前底段支气管、外后底段支气管；Ⅱ型39例(18%)：基底干支气管3分支，即内前底段、外侧底段、后底段支气管。

Firstly, velocity expression of translational parallel manipulator was presented based on the screw theory. Secondly, the actuated screw, the actively unactuated screws and idle screws of each limb were determined according to the reciprocal screw theory. Then, all basic kinematic chains were enumerated by means of the number of limb connectivity and the limbs containing closed-loops were obtained by replacing the passive prismatic joints in the basic kinematic chains with planar closed-loop structures.

首先基于螺旋理论给出移动并联机构的速度表达式，然后根据互易螺旋理论确定出分支的主动螺旋、可动非主动螺旋和惰性螺旋，再依照分支连接度的不同列举出所有可行的基本分支运动链，并通过运动副替换得到分支中含有闭回路结构的运动链，最后利用所综合出的支链按照主动副的配置要求将动平台和静平台连接起来即可实现预期的机构。

Dendrogram divided 37 haplotypes into two major clusters, capra aegagrus clustered into lineage A, while capra falconeri clustered into other lineage. Lineage A is the predominance lineage of the 7 goat populations, while lineage B has a relatively small proportion.

系统发育树将37种单倍型划分为两个较大的分支，角猾羊1条序列聚入A分支，而捻角山羊则自成1支。A分支为7个群体的优势类型，B分支的影响相对较小。

On this basis, using the same theories and methods, we set up the three-dimensional steady-state models of ideal well productivity about a reverse double-branch horizontal wells, the three branches of radial horizontal wells, fish-bone shape three branches horizontal wells and two-dimensional four branches horizontal wells In five reservoirs respectively.

在此基础之上，运用同样的理论和方法，建立了反向双分支水平井、辐射状三分支水平井、鱼骨形三分支水平井和二维四分支水平井这四种分支水平井分别在以上五种油藏中的三维稳态理想井产能模型。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失