Application of Multivariate Analysis Method in Evaluation of Quality and Traits of Sichuan Ophiopogon japonicus

[Objectives] To study the relationship between the yield and total saponin content of Sichuan Ophiopogon japonicus. [Methods]The multi-indicator function model of Sichuan O. japonicus was established by using the multivariate analysis method and taking the yield of and total saponin content of Sichuan O. japonicus as indicators. [Results] In the multivariate non-linear fitting,the Pearson correlation test was used to reduce the dimension of the model,and the significant correlated variables were rejected,leaving three independent variables: the total fresh weight of the plant( x_1),the fresh weight of the aboveground part(x_2) and the fresh weight of fibrous roots(x_3),established the total saponin( y) function model for Sichuan O. japonicus: y = a_1+a_2x_2+ a_3x_3+ a_4x_1x_2+ a_5x_1x_3+ a_6x_2x_3+ a_7x_1~2+ a_8x_2~2+ a_9x_3~2.[Conclusions]When the total fresh weight of plant,fresh weight of aboveground part and fresh weight of fibrous roots were known in Sichuan O. japonicus root tuber,the total saponin content could be estimated by polynomial of these three variables. The establishment of this functional model system is expected to provide a scientific basis for the scientific prediction of the yield and total saponin content of Sichuan O. japonicus.

Efects of diferent casting mould cooling rates on microstructure and properties of sand-cast Al-7.5Si-4Cu alloy

In this work, Al-7.5Si-4Cu alloy melt modified by Al-10Sr, RE and Al-5Ti-B master alloys was poured into multi-step moulds made from three moulding sands, including quartz, alumina and chromite, to investigate comparatively the effects of different cooling rates of the casting mould on the alloy's microstructures and mechanical properties. The results show that with an increase in wall thickness, the cooling rate decreases, the dendrite arm spacing(DAS) increases significantly and the mechanical properties decrease steadily. The elongation is more sensitive to the cooling rate than the tensile strength. No obvious trend of the effect of wall thickness on hardness of the alloy was found. When the cooling rate is at its greatest, the microstructures and mechanical properties are the best when using chromite sand. The improvement of the properties is mainly attributed to the decrease of the DAS, the grain refinement and the metamorphic effect. Each of the three has a strong impact on the microstructures. Furthermore, a series of fitting models was established based on the data of the DAS to predict the mechanical properties of the multivariate sand-cast Al-7.5Si-4Cu alloy,

Paleocontinental Reconstruction:Methodology,Computer Software and an Example of Application

Paleocontinental reconstruction is of the nature of multidisciplinary analysis . This paper discusses the significance of some more important disciplines , including paleomagnetism , paleoclimatology and paleobiogeography. Top attention should be paid to the synthetic analysis and geological explanation of geophysical data . Reassembling of the paleocontinents by geometric similarities is preliminary, geological considerations should receive more attention . Several rules constraining the reconstruction are proposed and Eider poles used to reassemble some separated Precambrian median massifs to their mother continents are given . A computer software for paleocontinental reconstruction , GUDALU , is introduced . The software is flexible in that it gives the user maximum freedom to demonstrate his or her geological opinions by providing means of organizing geographic data and rotational parameters ,many kinds of map projection of different features and dynamic editing of the reconstruction maps . Finally, an example of Mesoproterozoic reconstruction is demonstrated .