前期

Firstly, This paper processes geometry filtration based on character of orbit's apogee and perigee after orbit model is analyzed and based. Secondly Space Debris is separated into two kinds, coplanar and not coplanar according as location interrelation of target and debris. In Dynamic filtration's processing, considering prediction time limit and orbit perturbation, secular effects which have increaser effect is considered so that some need catching danger time point is appeased, some law about time when target and debris pass intersectant line each other is inferred, when debris and object are in different plane and some similar law also is inferred otherwise. The time list is arithmetical progression. These laws can improve calculation efficiency remarkably; Lastly orbit predict is a course approaching least distance. Danger time point in the last step become beginning time point from which debris and object's position and velocity are calculated by SXP4 Model which is an analytic model.By result, determine that relative movement trend is closer or apart, farther calculate the interval apart from time when predictive least relative distance occurs. Least relative distance and time when least distance occurs is calculated finally. It is a fast approach course adopting varied interval.

本文在分析、建立轨道摄动计算模型的基础上，首先采用基于轨道远、近地点特征对大量编目在册的空间碎片进行初步几何静态筛选，然后根据碎片与目标轨道面的相对位置特点把碎片分为异面与准共面两种情况以进行动态筛选，在筛选过程中考虑到预报时限长度和轨道摄动影响，引入了轨道摄动中具有积累效应的长期项以满足危险时间点的捕捉要求，利用了长期项摄动变化线性的特点导出了碎片与目标异面情况下各自过交线的时间序列成准等差数列的规律性和准共面情况下类似的规律性，从而显著地提高了前期轨道筛选的计算效率；最后对剩余危险碎片和目标飞行器利用SXP4轨道预报模型在前期轨道筛选的基础上以各个危险探测时间点为预报的时间起点，并根据预报计算结果，分析目标和碎片在该时间点的运动趋势是相互远离还是相互接近，推出预计最小相对距离发生时刻相对此刻的时间长度，得到其随时间变化的局部最小相对距离以及危险距离发生的时刻和相对速度，这是一个采用变时间步长、快速逼近最小相对距离的过程。

To achieve such a complex structure, need to do a lot of preliminary work, the higher initial cost.

为了实现这种复杂的结构，需要做大量前期工作，前期费用较高。

During the early stages of fruit development, content of IAA in receptacles was significantly negatively correlated with the activity of soluble IAO in cytoplasm and ionic bond IAO in cytoderm.

果实发育前期，花托中IAA含量与细胞质可溶性IAO、以离子键结合的IAO的活性显著负相关；发育前期和后期IAA含量与POD活性显著正相关。

Objective To evaluate Nd:YAG in treatment of closed angle glaucoma at the preelinical stage. Methods Peripheral iridectomy with Nd:YAG was performed on 26 cases (26 eyes) of preclinical glaucoma.

目的 评价Nd：YAG激光治疗闭角型青光眼临床前期的疗效方法采用Nd：YAG激光对26例(26眼)青光眼临床前期施行周边虹膜切除术，术後随访7～24月。

According to the ultrastrucral observation of PMCs, three successively specific phases could be distinguished as leptotene, zygotene and pachytene in early prophase Ⅰ of Arabidopsis.

通过对拟南芥菜减数分裂前期花粉母细胞的形态学观察，我们认为在早前期Ⅰ中，拟南芥菜又可以分为三个时期：细线期、偶线期和早粗线期。

The spatial distribution pattern of mixed spider populations in rice fields was different during different development stages of rice plant.

在早稻发育的前期、中期和后期，稻田蜘蛛混合种群的空间分布模式分别是聚集的、随机的和聚集的；在晚稻发育的前期、中期和后期，其空间分布模式依次是均匀的、聚集的和均匀的。

On the design of algorithms, a novel exact hierarchical delay analysis method for general circuits is proposed; based on the sensitization theorem for sequential circuits, an exact minimizing clocking method is proposed; based on Boolean process, a waveform simulation method considering interconnecting delay for logic circuit and a parallel waveform simulation method are proposed; a new method that transforms bit-level waveform polynomial to word-level polynomial model is proposed; a multiple valued synthesis algorithm based on multiple valued Boolean process and a wire-centered delay synthesis policy are proposed, in which timing planning, floorplanning, wire planning and optimal clock skew in early design are considered; a two-layers channel routing method for minimizing crosstalk under grid mode is proposed; based on the transition numbers theorems for waveform polynomial, a new method for generation of test with noise effects is proposed.

算法设计方面，提出了一种精确的通用电路层次化延时分析方法；基于时序电路的敏化定理提出时序电路最小时钟周期精确确定方法；提出基于Boolean过程论的考虑互连延迟的逻辑电路波形模拟方法，在分析了波形模拟适合并行化基础上，进一步提出一种并行波形模拟算法；提出一种将位级电路波形多项式描述转化成字级多项式描述的新方法；提出一种基于多值Boolean过程的多值电路综合算法以及一种将前期设计定时规划、前期设计的布局规划和线网结构化方法及低偏移的时钟分配等技术相结合的面向互连延时的综合策略；提出一种串绕最小化的网格模式下的双层通道布线方法；从波形多项式描述跳变数的定理出发提出了一种考虑噪声效应的测试生成新方法。

The system is controlled by continuous review installation stock policies. This paper presents an improved approximated method that the leadtime demand of warehouse is approximated by the normal distribution, and the leadtimes demand of retailers are approximated based on negative binomial distribution.

论文给出改进的近似方法，即用正态分布近似分销中心提前期内需求的分布，用更符合实际的负二项分布近似零售商提前期内需求分布，从而建立了二级分销系统期望总成本近似模型。

At the same time,the morphological variations of the ampulla and ithmus of the oviducts were observed and measured by light microscopy. Results The serum levels of estradiol were E＞PE＞ME＞DE＞OVX.The differences between the two groups were significant.The height of the oviductal epithelia was E＞PE＞DE＞ME.After ovariotomy,the epithelia of the oviduct were atrophied and regressive.

结果 大鼠血清雌二醇浓度依次为：动情期组＞动情前期组＞动情后期组＞动情间期组＞去卵巢组，各组间差异均有显著性；输卵管粘膜上皮高度在动情周期中变化为：动情期组＞动情前期组＞动情间期组＞动情后期组；去卵巢后，输卵管粘膜上皮萎缩。

Chapter four first analyzes the forming reason for the supply chain satety st -ock and analyzes the relationship between lead time and the safety stock of com -ponent commonality, and it establishes a decision framework of safety stock. There is a case study based on an Auto-electric Motor Company.

第4章介绍了供应链的安全库存的形成，并结合汽车电机产品的特点和企业库存特点，分析了随机提前期下采用通用件对安全库存的影响，提出了随机提前期下安全库存的控制策略，并在结合实例分析了安全库存控制策略选择问题。

In the negative and interrogative forms, of course, this is identical to the non-emphatic forms.

。但是，在否定句或疑问句里，这种带有"do"的方法表达的效果却没有什么强调的意思。

Go down on one's knees;kneel down

屈膝跪下。。。下跪祈祷