Atmospheric precipitation

The orographic dynamical and thermodynamical effects and their influences on precipitation and cloud physics are analyzed in detail.

中国气象局，北京 100081

This review summarizes some recent research advancements about the orographic influences on surface precipitation.

中国科学院研究生院，北京 100049

The orographic effect and wind enhances precipitation where slope face wind.

对LGM时期，其外部强迫为该时期的年平均空气温度、海平面高度和ELA。

Significant precipitation occurred over northern and northeastern Taiwan during the passage of both types of anafronts, whereas it was larger in the cold-type than that in the warm-type. For the warm-type, significant rainfall also occurred over southeastern Taiwan because the orographic lifting of the warmer and moist southerlies.

暖型与冷型上滑锋在台湾北部与东北部均有较显著降水，但冷型上滑锋的降水强度较大；暖型上滑锋在东南部锋上的降水强度有另ㄧ大值，此乃因锋前南风分量带来暖湿空气，且东南部位在迎风面，因地形举升故有较大降水。

A kind of spherical microporous silica was synthesized by precipitation with the tetraethyl orthosilicate as a silica precursor and the block ploymer P_(123 as a template. The characterizations by the BET, FSEM and XRD showed that the spherical microporous silica has diameter of 3～4 μm, amorphous pore size of 0.9～1 nm and the specific area of 216±

以正硅酸乙酯作硅源，嵌段共聚物为模板剂，采用沉淀法合成均匀的实心球形二氧化硅微孔材料，BET、FSEM和XRD等表面分析手段表征表明，我们合成的二氧化硅微孔材料具有3～4μm的粒径和不规则分布的0.9～1nm的孔径以及216±3.5m2/g的比表面积。

A modified γ-Al〓O〓 was prepared by a special precipitation method with aluminum nitrate solution containing a certain amounts of orthosilicic acid and ammonia aqueous solution. Compared with commercial γ-Al〓O〓, the modified γ-Al〓O〓 was an effecient catalyst for dehydration of tetrahydrofurfuryl alcohol to dihydropyran. The results revealed that the strong acid sites on the surface of the catalyst may play a crucial role in this reaction.

并以硝酸铝和氨水为原料，用沉淀法制备出一种高比表面和拥有较多强酸中心的γ-Al〓O〓，它在四氢糠醇开环脱水制备二氢吡喃的反应中有优良的催化活性，通过比较此γ-Al〓O〓和普通商业γ-Al〓O〓的Py-TPD图，发现强酸中心在制备二氢吡喃的反应中可能具有关键的作用。

The microstructure evolution and composition distribution of the 7A55 cast and homogenized alloy were studied by optical microscopy, scanning electron microcopy, energy dispersive spectrometer, transmission electron microscopy and X-ray diffractometry. The homogenizing and overburnt temperatures of the alloy were determined. Meanwhile, the diffusion kinetics of the alloy elements during homogenizing treatment was investigated and the homogenizing kinetic equation was deduced according to Fick's First Law of diffusion. The diffusion of alloy elements, precipitation of Al3Zr particles and the conglomeration and globe of the insoluble phases were explained by the equation during homogenization.

摘 要：采用光学显微镜、扫描电镜、能谱分析、透射电镜和X射线衍射分析等研究了7A55合金铸态与均匀化显微组织演化与成分分布，确定了该合金的均匀化处理温度与过烧温度，研究了铸锭均匀化动力学过程，利用菲克定理导出了均匀化动力学方程，利用动力学方程对均匀化过程中合金元素的扩散、 Al3Zr的析出、难熔相的聚集和球化现象进行了解释。

Gold deposit ; telluride minerals ; paragenetic relationship ; precipitation mechanism

金矿；碲化物；共生关系；沉淀机制

The experimental results show that CaO has dual effects on the precipitation and growth of the perovskite phase.

实验结果表明：CaO加入量对钙钛矿结晶及晶体生长有双重影响。

After this, phagocytic cells will form the antigen-antibody reaction or precipitation Group phagocytic cells digest.

在这之后，吞噬细胞就会将抗原抗体反应形成的沉淀或细胞集团吞噬消化。

However it can often be frust ating for a child when people are unable to pronounce their name.

但它往往可以令人沮丧的一个孩子当人们无法断言他们的名字。

All these compounds were obtained from this genus for the first time. Compound, 4-cumylphenol, was a new nature product.

所有化合物均为首次从本属海藻中分离得到，其中4cumylphenol为新天然产物。