一次粒子

纳米TiO2母料在LLDPE/LDPE复合体系中具有良好的分散性，复合薄膜中的纳米TiO2为一次粒子。

LDPE / nano-TiO2 matrix has a well dispersion in LLDPE / LDPE composites , and nano-TiO2 particles in composite films are primary particle with nano scale .

一次粒子聚集成粒径30～50nm、质量分形维数Dm≈27的二次粒子。

Primary particles are aggregated into 30 ~ 50nm secondary particles with mass fractal dimension D m ≈ 2.7 .

在水解体系中加入适宜浓度的盐酸，可以增大水合TiO2晶粒尺寸，增强一次粒子之间的静电排斥力，以及促进以金红石为主的沉淀产物的生成；

The suitable amount of HCl added to the hydrolysis system can increase the particle size , strengthen the electrostatic repulsive force between two primary particles , and facilitate the generation of rutile product .

大气中超细颗粒物（PM2.5）的产生途径主要包括直接排入大气中的一次粒子，以及大气中的气态前驱物通过光化学作用转化生成的二次粒子。

The ultrafine particles ( PM2.5 ) in atmosphere include primary particles discharged into the atmosphere directly , and secondary particles generated from gas precursor through the photochemical role .

在此条件下合成的碱式碳酸铝镁粉末一次粒子的平均粒径约80nm，其形貌为球形，收率为95.2%。

Under this conditions , the average grain size of the spherical basic aluminum magnesium carbonate powder was about 80 nm , and the yield was up to 95.2 % .

采用XRD与TEM对产物粉末进行表征，结果表明，所合成的产物为碱式碳酸钠铝，其一次粒子的平均粒径约80nm，收率为96%。

The product is characterized by XRD and TEM . The results showed that the product is basic sodium aluminum carbonate , and the average particle size of the basic sodium and aluminum carbonate powder is about 80 nm , and the yield is up to 96 % .

在此条件下合成的碳酸锌粉末及其在350℃煅烧2h所得到的氧化锌粉末的一次粒子的平均粒径分别约35和20nm。

Under such conditions , the average diameter of particles for the zinc carbonate powder was about 35 nm . The nanometer zinc oxide was obtained when the zinc carbonate was pyrolyzed at 350 ℃ for 2 h , and its average diameter of particles was about 20 nm .

西安市一次晴空气溶胶粒子的观测分析梅雨对大气气溶胶粒子的清除

A case analysis of aerosol particles observation under fine weather over Xian

③中肠不仅是一次感染时病毒粒子复制的场所，它完全可能被病毒粒子二次感染。

In other words , the midgut is not only a primary infection origin , but also a tissue susceptible to secondary infection ;