黑白花奶牛的外貌评分随年龄不同而发生变化。那么如何比较不同年龄母牛的外貌优劣呢?美国荷斯坦牛协会广泛推行的是BAA,即品种年龄平均值(Breed Age Average,BAA)。它是一个相对百分值,等于母牛的实际评分经年龄校正后除以品种平均值再...黑白花奶牛的外貌评分随年龄不同而发生变化。那么如何比较不同年龄母牛的外貌优劣呢?美国荷斯坦牛协会广泛推行的是BAA,即品种年龄平均值(Breed Age Average,BAA)。它是一个相对百分值,等于母牛的实际评分经年龄校正后除以品种平均值再乘100,即: BAA(％)=实际评分×年龄校正因子/品种平均值×100 如果母牛的外貌评分等于它所在年龄组的品种均值,那么该母牛的BAA为100。展开更多
A series of new complexes of formula Ln_2[H_2(BAA)_2en]_3nH_2 Otwhere Ln- La, Pr, Eu, Cd, Dy, Er, Yb, n-1-4) have been prepared by the reaccLon of lanthanide ions with acycllc compartmental ligand X, N'-bis(benzoy...A series of new complexes of formula Ln_2[H_2(BAA)_2en]_3nH_2 Otwhere Ln- La, Pr, Eu, Cd, Dy, Er, Yb, n-1-4) have been prepared by the reaccLon of lanthanide ions with acycllc compartmental ligand X, N'-bis(benzoylacetylacetone)ethylenediamine (H_4(BAA)_2 en) in methanol. IR and UV spectra, as well as TC DAT analysis prove that the ligand and the Lanthanide ions have coordinated. The coordination number is 12 and the complexes may be of double sandwiched structure.展开更多
文摘黑白花奶牛的外貌评分随年龄不同而发生变化。那么如何比较不同年龄母牛的外貌优劣呢?美国荷斯坦牛协会广泛推行的是BAA,即品种年龄平均值(Breed Age Average,BAA)。它是一个相对百分值,等于母牛的实际评分经年龄校正后除以品种平均值再乘100,即: BAA(％)=实际评分×年龄校正因子/品种平均值×100 如果母牛的外貌评分等于它所在年龄组的品种均值,那么该母牛的BAA为100。
基金supported by the National Natural Science Foundation of China
文摘A series of new complexes of formula Ln_2[H_2(BAA)_2en]_3nH_2 Otwhere Ln- La, Pr, Eu, Cd, Dy, Er, Yb, n-1-4) have been prepared by the reaccLon of lanthanide ions with acycllc compartmental ligand X, N'-bis(benzoylacetylacetone)ethylenediamine (H_4(BAA)_2 en) in methanol. IR and UV spectra, as well as TC DAT analysis prove that the ligand and the Lanthanide ions have coordinated. The coordination number is 12 and the complexes may be of double sandwiched structure.
