正

They stopped. This one is dead center dead center in the brain.

全停止了。这个东西在正中央，脑子的正中央，就像一小米粒那么大。

Two kinds of stable decagonal quasicrystals and 16 approximants have been found in Al-Cr- alloys by means of selected-area electron diffraction, high resolution electron microscopy image and X-ray single crystalline diffraction.

用选区电子衍射和高分辨像等手段，确定了Al-Cr-合金系中的16个准晶近似相，其中的7个准晶近似相为新相，它们是：六方τ相，六方μ′相和正交ε相，以及周期为3.72nm的正交(2/1，2/1)，(1/1，3/2)，(2/1，3/2)相和α=2.29nm，c=3.71nm，β=108°的单斜相。

Objective To evaluate the most effective method of fluoride application to prevent decalcification of enamel before,during and after etching in orthodontic treatment.

目的探讨氟化物在正畸治疗中预防牙釉质脱矿的最佳使用方法。方法制备正畸拔除的前磨牙96颗，随机分成4组，分别为对照组及酸蚀前、中、后用氟组，粘结托槽后，将每个样本分别放入装有2ml酸性人工唾液的试管。

The gas phase oxidative cracking of decane and hexane has been investigated in this paper.

采用石英管反应器，常压下研究了正癸烷和正己烷的气相氧化裂解过程。

While (superscript 4) He is the decay product of uranium and thorium, mainly concentrated in the continental crust, and is approximately proportional to the heat flux of crust.

由於铀、钍元素在大陆地壳中富集，(上标 4) He通量与地壳热流呈正相关关系；同时(上标 3) He通量与地幔热流之间呈正相关。

EOF, EOF procedures, principal component analysis procedure, suitable for vector field orthogonal decomposition.

经验正交函数，EOF程序，主成分分析程序，适合做向量场的正交分解。

The paper first introduces the basic principle of Karhunen-Loeve decomposition for stochastic processes, and outlines the essential properties of the decomposition. A method based on the Hartley orthogonal bases is proposed to decompose stochastic processes.

介绍了随机过程Karhunen-Loeve分解的基本原理，指出了其在随机过程展开中所具有的优势与局限性，针对Karhunen-Loeve分解在求解特征问题中存在的困难，采用Hartley正交基作为展开函数，发展了一类基于Hartley正交基的随机过程展开方法。

According to the features of non-resistance puff, the "slight deflagration" mechanism is extended.

根据层燃炉非阻力型冒正压的特点，发展了"微爆燃"理论，提出涡脱落诱导声共振的燃烧振荡机理，并运用该机理对非阻力型正压发生的条件进行了分析。

Thus the prevention of enamel demineralization during orthodontic treatment has been a chief problem for orthodontists to consider.

因此，预防正畸治疗中的牙釉质脱矿的发生就成为正畸医师首先要考虑的问题。

The fluoride-vanish on the orthodontic treatment of enamel demineralization has significant inhibitory effect.......

氟保护漆对正畸治疗中的釉质脱矿有明显抑制作用。釉质脱矿；氟保护漆；正畸

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。