Dongguashan deposit is a large porphyry-skarn copper（gold） deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magm...Dongguashan deposit is a large porphyry-skarn copper（gold） deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magma origin, rock-forming dynamic background and rock-forming process were studied, and the rock-forming mechanism of Qingshanjiao intrusion was discussed, based on geological characteristics, detailed observation of petrography and systematic investigation of petrochemistry, trace elements and REE geochemistry characteristics of Qingshanjiao intrusion. The results show that Qingshanjiao rock body belongs to high-K calc-alkaline series with higher LREE elements, Th, Rb and Sr abundance, but depleted in HREE elements, Ba, Nb and Ta. The primary magma originated from the mantle-crust mixtures which were caused by basaltic magma of mantle mixing with syenite magma of partial melting of the lower crust, and the formation environment of Qingshanjiao intrusion was emplaced in the transitional environment from compression to extension. The Harker diagram and hybrid structures of plagioclase and potassium feldspar indicate that the fractional crystallization occurred in the process of magmatic evolution. The petrochemistry, trace elements and REE geochemistry characteristics indicate that the magma was contaminated by crustal material during the rock-forming. These results suggested that the Qingshanjiao intrusion was formed by fractional crystallization and assimilation and hybridization of mantle-crust magma in the transitional environment from compression to extensional.展开更多
The sphere is a common object in uncountable engineering problems, which not only appears in structural elements like domes but also in thousands of mechanisms normally used in diverse kinds of machines. To design, ca...The sphere is a common object in uncountable engineering problems, which not only appears in structural elements like domes but also in thousands of mechanisms normally used in diverse kinds of machines. To design, calculate and analyze the behaviour on service of spherical elements, it is essential to have a good method to create an ordered group of discrete points of the spherical surface from the parametric equations commonly used to define the sphere continuously. One of the best known and widely used in high-level programming environment is MATLAB. The programming language has thousands of functions, lots of them specially designed for engineering processes. One of these functions generates a sphere knowing a given radius and shows the result. Nevertheless, this function is really imprecise because it is based on parallels and meridians besides the obtained vertices do not keep a constant distance each other. This causes the fact that it would be appropriate to design a new function to generate accurate discrete approximations of the sphere. The objective of this paper is to create a low-level function in MATLAB to obtain a discrete sphere with high regularity and high approximation in order to provide a good base to solve sphere-based engineering problems. To ensure a perfect symmetry and high regularity platonic bodies, MATLAB will be used as a base to divide the continuous spherical surface in a finite number of regular triangles. The obtained results for the different seed bodies will be represented graphically and compared to each other. The accuracy of each method will be evaluated and compared too.展开更多
基金Project(20091100704)supported by the Special Funds for Scientific Research of Land and Natural Resources,ChinaProject(2015CX008)supported by the Innovation Driven Plan of Central South University,China
文摘Dongguashan deposit is a large porphyry-skarn copper（gold） deposit in Tongling ore district. The Qingshanjiao intermediate acid intrusion of Yanshanian had a direct genetic relationship with mineralization. The magma origin, rock-forming dynamic background and rock-forming process were studied, and the rock-forming mechanism of Qingshanjiao intrusion was discussed, based on geological characteristics, detailed observation of petrography and systematic investigation of petrochemistry, trace elements and REE geochemistry characteristics of Qingshanjiao intrusion. The results show that Qingshanjiao rock body belongs to high-K calc-alkaline series with higher LREE elements, Th, Rb and Sr abundance, but depleted in HREE elements, Ba, Nb and Ta. The primary magma originated from the mantle-crust mixtures which were caused by basaltic magma of mantle mixing with syenite magma of partial melting of the lower crust, and the formation environment of Qingshanjiao intrusion was emplaced in the transitional environment from compression to extension. The Harker diagram and hybrid structures of plagioclase and potassium feldspar indicate that the fractional crystallization occurred in the process of magmatic evolution. The petrochemistry, trace elements and REE geochemistry characteristics indicate that the magma was contaminated by crustal material during the rock-forming. These results suggested that the Qingshanjiao intrusion was formed by fractional crystallization and assimilation and hybridization of mantle-crust magma in the transitional environment from compression to extensional.
文摘The sphere is a common object in uncountable engineering problems, which not only appears in structural elements like domes but also in thousands of mechanisms normally used in diverse kinds of machines. To design, calculate and analyze the behaviour on service of spherical elements, it is essential to have a good method to create an ordered group of discrete points of the spherical surface from the parametric equations commonly used to define the sphere continuously. One of the best known and widely used in high-level programming environment is MATLAB. The programming language has thousands of functions, lots of them specially designed for engineering processes. One of these functions generates a sphere knowing a given radius and shows the result. Nevertheless, this function is really imprecise because it is based on parallels and meridians besides the obtained vertices do not keep a constant distance each other. This causes the fact that it would be appropriate to design a new function to generate accurate discrete approximations of the sphere. The objective of this paper is to create a low-level function in MATLAB to obtain a discrete sphere with high regularity and high approximation in order to provide a good base to solve sphere-based engineering problems. To ensure a perfect symmetry and high regularity platonic bodies, MATLAB will be used as a base to divide the continuous spherical surface in a finite number of regular triangles. The obtained results for the different seed bodies will be represented graphically and compared to each other. The accuracy of each method will be evaluated and compared too.
