准的

To compare the difference between laser in situ keratomileusis and laser epithelial keratomileusis for correction of hyperopia.

目的 比较准分子激光上皮瓣下角膜磨镶术与准分子激光原位角膜磨镶术在矫正远视及远视散光中的临床疗效。

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。

He didn't talk with JG, but he says that JG has been well still adapting to the new circumstances

他没有和准说话，但他说准过的很好。

Objective To observe and compare the changes in corneal sensitivity after photorefractive keratectomy and laser in-situ keratomileusis for myopia.

目的 观察和分析准分子激光屈光性角膜切削术(photorefractive keratectomy， PRK)和准分子激光原位角膜磨镶术(laser in-situ keratomileusis，LASIK)治疗近视后角膜知觉的变化。

Objective To study the effect,stability and safety of photorefractive keratectomyand excimer laser in situ keratotomy.

目的 探讨准分子激光角膜切削术及准分子激光原位角膜磨镶术矫治角膜放射状切开术后残留近视的安全性、稳定性和可靠性。

EduPAL provides a total package that includes accommodation arrangement,airport reception and transfer to lodging,immigration process application and renewal,social visit/student pass sponsorship and student welfare.

提供并安排一条龙服务：机场接待，安排住宿，换取准证及到期更新准证，社会参观、学生通行证，保证学生的福利。

A registration experiment based on the averaged periodogram algorithm is carried out finally, whose result proves that the new algorithm could improve the accuracy of registration efficiently.

最后使用平均周期图法进行了配准实验，试验结果验证了新算法在提高配准精度方面的有效性。

In accordance with the correspondence principle of medium?

根据中期旋回与准层序组相对应以及短期旋回与准层序相对应的原则，将广北 12 -斜 1井沙四段 1～ 4砂层组划分出 4个中期旋回，18个短期旋回，并运用旋回等时对比技术对广北地区进行了精细层序地层对

A fire\|new theory for periodic or quasi\|periodic signal sampling is proposed,w hich is especially for sampling high\|frequency wideband periodic or quasi\|peri odic signal by low sampling rate system.

涉及一种周期或准周期信号的采样技术，特别适用于低频采样系统采集高频宽带周期或准周期信号。

By using the observed data, ten canonical cases of Kunming quasi－stationary front during 1993－1995 in winter and spring seasons are studied.

利用常规探空资料，选取1993－1995年冬、春季节中10个昆明准静止锋典型个例作了合成计算，分析了昆明准静止锋的结构。

She gently rebuff ed him, but agreed that they could be friends

她婉言拒绝了，但同意作为朋友相处。

If in the penal farm, you were sure to be criticized.

要是在劳改农场，你等着挨绳子吧！