The soils in the region were characterized by thin layer , weak structure , gravel / fragmental composition , compacted surface and drought , etc . soil water properties are important factors affecting vegetative rehabilitation in spite of low soil organic content and lack in soil nutrients 干熱河谷的土壤特征表現(xiàn)為土層淺薄、土壤結(jié)構(gòu)差、土壤石質(zhì)粗骨性強(qiáng)或表土緊實(shí)、土壤干旱等。雖然土壤有機(jī)質(zhì)含量低、有效養(yǎng)分也較缺乏,但是土壤水分性質(zhì)是植被生長(zhǎng)恢復(fù)的關(guān)鍵制約因素。
In the second part , we investigate the compact submanifolds m with the parallel isoperimetric section in the real space forms rm ( c ) and prove that if there exists a parallel isoperimetric section on m , and the sectional curvature of m is always greater than zero , then m is contained in a hyper - sphere ; and get that the gauss curvature of the compact surfaces m with constant mean curvature in constant curvature space r4 ( c ) is always greater than zero , then m is a totally geodesic surface or a sphere , where an isoperimetric on m means a unit normal vector field defined globally on m with m1 ( ) = constant ( 2 )研究了實(shí)空間形式r ~ m ( c )中具有平行等參截面的緊致子流形m ,證明了具有一平行等參截面的子流形m ,如果m的截面曲率恒正,則m包含在r ~ m ( c )的一個(gè)超球面內(nèi);對(duì)于常曲率空間及r ~ 4 ( c )中具有常平均曲率的緊致曲面m ,如果m的高斯曲率處處大于零,則m或?yàn)閞 ~ m ( c )中的全測(cè)地曲面或?yàn)橐磺蛎妗_@里m上的等參截面是m上整體定義的單位法向量場(chǎng),使得m關(guān)于它的平均曲率m _ 1 ( )是常數(shù)。
The study on the core - shell particles shows , one extrenity of silane coupling agents at the surface of the composite particles after adding aps are connected with the fe particles . and the other extrenity outside can polymerize with the active silica . the slick and compact surface of the composite particles shows the obvious core - shell structure . the surface of the composite particles are composed of the combined apex of the element si , o , c , h . the element o is superfluous to the element si 對(duì)納米復(fù)合鐵粒子研究表明,在aps改性的鐵納米粒子表面硅烷偶聯(lián)劑氨基一端連接鐵粒子,另一端對(duì)鐵粒子外面,能與活性硅聚合。鐵納米復(fù)合粒子顆粒表面光滑致密。核殼復(fù)合粒子表面主要由si , o組成,伴隨著微量的c , h元素的峰,核殼復(fù)合粒子表面氧對(duì)硅有富余。