强对流岩浆房中晶体的沉淀

关于岩浆房中结晶分异作用的机制仍存许多争论。晶体沉淀的的传统假说已被伴随成分对流的“原地”结晶这种概念所代替。然而,有关层状侵入体的观察结果对此却有疑义。由于岩浆房中岩浆对流速率通常比斯托克斯定律(Stokes’Law)所预测的晶体沉淀速率大得多,因此,关于晶体沉淀在理论上产生了怀疑,不过,目前关于这种强对流下的晶体沉淀尚没有实验研究。本文提出的物理推导和室内实验结果表明,在上述条件下粒子沉淀现象可以用一种简单的理论来解释。这种理论对于岩浆房中晶体沉淀的应用表明,不论多大的对流速率,晶体沉淀可能都是一种有效的结晶分异机制,至少在玄武岩岩浆房中是这样。

纺织配色专家系统——Smart Match

一、引言 配色处方计算质量的好坏主要取决于描述反射、吸收和散射之间关系的算法的有效性。大多数配色计算都采用库贝尔卡—芒克(Kubel-ka-Munk)理论和Beer定律。但是,实际使用的染料、染色工艺以及纺织品的性能却只能部分满足这些理论所要求的边界条件。因此,一次配色的小误差成功率通常只有30—80％。为了有效地提高一次配色的质量,Datacolor Inter-national公司推出了一种新的计算方法,该方法命名为“Smart Match”。这种软件除了传统配色计算之外,还包括能在第一次染色前就消除因实际情况与理论条件不一致而引起的偏差的校正算法。有了这种校正算法。

Analysis of variograms with various sample sizes from a multispectral image

Variogram plays a crucial role in remote sensing application and geostatistics.It is very important to estimate variogram reliably from sufficient data.In this study,the analysis of variograms computed on various sample sizes of remotely sensed data was conducted.A 100×100-pixel subset was chosen randomly from an aerial multispectral image which contains three wavebands,Green,Red and near-infrared(NIR).Green,Red,NIR and Normalized Difference Vegetation Index(NDVI)datasets were imported into R software for spatial analysis.Variograms of these four full image datasets and sub-samples with simple random sampling method were investigated.In this case,half size of the subset image data was enough to reliably estimate the variograms for NIR and Red wavebands.To map the variation on NDVI within the weed field,ground sampling interval should be smaller than 12 m.The information will be particularly important for Kriging and also give a good guide of field sampling on the weed field in the future study.