考虑在一个大气压下液态铝的凝固,对于不同程度的过冷度,即:△ T=1,10,100和200℃,计算: (a)临界晶核尺寸 (b)半径为r+的晶核个数; (c)从液态转变到固态时,单位体积的自由能变化ΔG*(形核

影响土壤比重的因素: 土壤比重仅仅取决于土壤固相颗粒的物质组成。 Since a large portion of most soils is composed of particles derived from quartz minerals, the particle density of most soils is near 2.6 g/cc which is the density of quartz. Variations in the particle density are due to the presence of heavier minerals like iron oxides or lighter organic components

第一节土壤有机质来源及其组成特点 一、有机质来源 (一)来源于数目众多微生物 1微生物是最早出现在母质中的有机体。成为最早的土壤有机物质来源。 2微生物数目繁多,生活代谢周期短。1g肥沃的表土含有细菌可在10亿以上。最多细菌为杆菌,每英亩细菌活质可超过2000磅,每公顷2000公斤

Recall from lecture 22 °Flow value:f=f(s,V) Cut: Any partition (S, T)of y such that s E S andt∈T Lemma. f=f(s, T) for any cut(S, T) Corollary. f(s, T) for any cut(S, T) Residual graph: The graph G=(v, ef) with strictly positive residual capacities c u, v) c(u,)-f(2y)>0

Negative-weight cycles Recall: If a graph G=(V, E) contains a negative weight cycle then some shortest paths may not exist

Balanced search trees Balanced search tree a search-tree data structure for which a height of o(g n)is guaranteed when implementing a dynamic set of n items

How fast can we sort? All the sorting algorithms we have seen so far are comparison sorts: only use comparisons to determine the relative order of elements E. g, insertion sort, merge sort, quicksort heapsort The best worst-case running time that weve seen for comparison sorting is O(nIgn) Is o(nlgn) the best we can do?

EROSPACE DYNAMiCS EXAMPLE: GWE ACCELERATIoN of THE TIP 0F认ERU0毛R人TM5Hc人AF LDk小 G For A650LUT # CCELER升T10 N UTH RES/∈ct T0wE工NERT1 AL FRAME (∈ TH IN THiS CASE) 0EFNE兵8uNcH0 f PoINTS

EROSPACE DYNAMiCS EXAMPLE: GWE ACCELERATIoN of THE TIP 0F认ERU0毛R人TM5Hc人AF LDk小 G For A650LUT # CCELER升T10 N UTH RES/∈ct T0wE工NERT1 AL FRAME (∈ TH IN THiS CASE) 0EFNE兵8uNcH0 f PoINTS

一、后备种公猪的管理 1、后备公猪: 8月龄、120G开始使用