基于地统计学方法,利用3种以海拔作为辅助变量的空间插值算法[局部平均的简单kriging法(simple kriging with locally varying mean,SKlm)、带有外部漂移的kriging法(krig-ing with an external drift,KED)和协kriging法(cokrging,COK)...基于地统计学方法,利用3种以海拔作为辅助变量的空间插值算法[局部平均的简单kriging法(simple kriging with locally varying mean,SKlm)、带有外部漂移的kriging法(krig-ing with an external drift,KED)和协kriging法(cokrging,COK)]计算了森林半腐层厚度的空间插值精度,并进行了交叉验证.结果表明:KED法既考虑了变量之间的空间变异,又考虑到影响局部空间变化的因素,与其他插值方法相比,其精度有很大提高;由于海拔与半腐层厚度之间的相关关系较弱,导致SKlm法的插值精度没有达到预期效果;COK法直接将海拔用于估计半腐层厚度,由于在边界地区缺乏采样点数据,因此边界地区的插值出现了多处突变区域.对比地统计学方法与距离反比权重法(inverse distance weighting,IDW)在本研究中的插值精度,除了KED方法的插值精度较高外,其余方法的插值精度均不及IDW,原因可能是利用辅助变量辅助地统计学插值时,主、辅助变量之间的相关关系在插值中起着重要作用.展开更多
An isoquinoline-3-carboxylate compound 3 was obtained with a moderate yield of 40% when N-acetyl-（3′-hydroxy-4′- methoxy-5′-methyl）phenylalanine methyl ester 1 was refluxed in HMTA/TFA. However, the anticipated p...An isoquinoline-3-carboxylate compound 3 was obtained with a moderate yield of 40% when N-acetyl-（3′-hydroxy-4′- methoxy-5′-methyl）phenylalanine methyl ester 1 was refluxed in HMTA/TFA. However, the anticipated product N-acetyl-（3′- hydroxy-4′-methoxy-5′-methyl-6′-formyl）phenylalanine methyl ester 2 could not be found. The possible mechanism was discussed in this article.展开更多
文摘基于地统计学方法,利用3种以海拔作为辅助变量的空间插值算法[局部平均的简单kriging法(simple kriging with locally varying mean,SKlm)、带有外部漂移的kriging法(krig-ing with an external drift,KED)和协kriging法(cokrging,COK)]计算了森林半腐层厚度的空间插值精度,并进行了交叉验证.结果表明:KED法既考虑了变量之间的空间变异,又考虑到影响局部空间变化的因素,与其他插值方法相比,其精度有很大提高;由于海拔与半腐层厚度之间的相关关系较弱,导致SKlm法的插值精度没有达到预期效果;COK法直接将海拔用于估计半腐层厚度,由于在边界地区缺乏采样点数据,因此边界地区的插值出现了多处突变区域.对比地统计学方法与距离反比权重法(inverse distance weighting,IDW)在本研究中的插值精度,除了KED方法的插值精度较高外,其余方法的插值精度均不及IDW,原因可能是利用辅助变量辅助地统计学插值时,主、辅助变量之间的相关关系在插值中起着重要作用.
文摘An isoquinoline-3-carboxylate compound 3 was obtained with a moderate yield of 40% when N-acetyl-（3′-hydroxy-4′- methoxy-5′-methyl）phenylalanine methyl ester 1 was refluxed in HMTA/TFA. However, the anticipated product N-acetyl-（3′- hydroxy-4′-methoxy-5′-methyl-6′-formyl）phenylalanine methyl ester 2 could not be found. The possible mechanism was discussed in this article.
