Marble is a metamorphic rock, which is one of the 3 basic rock types (magmatic, sedimentary, metamorphic) forming the earth’s crust. The major characteristic sought after in a rock mass in the field for it to be expo...Marble is a metamorphic rock, which is one of the 3 basic rock types (magmatic, sedimentary, metamorphic) forming the earth’s crust. The major characteristic sought after in a rock mass in the field for it to be exportable and usable as marble is its suitability to be cut in blocks. In the process of producing marble slabs from marble blocks, the blocks are expected not to contain potentially problematic hard or weak zones and their geomechanical and chemical properties should conform to the relevant standards. Ignoring of the geological properties of the rock in the process of deciding for marble production at a marble site and determination of production location, direction and method is the most important parameter that would increase production loss. In order to reduce losses by determination of geological properties of marble, many academic studies have been conducted on the effects of water saturation, temperature, freezing and thawing on its mechanical and fracture properties. There are further studies on crack propagation in marble under stress. However, even those marble blocks that are obtained based on geological parameters may suffer serious cracks or fractures due to stresses caused by their weight and geometry. Therefore, cutting direction is of critical importance in order to minimize marble waste in the process of cutting a marble block which is brought to the inventory or processing site with cracks, cavities or fractures. Certain studies exist within such context, where the geometry of the discontinuity within a block is determined using non-destructive methods, such as ultrasonic testing, in order to determine the appropriate cutting direction. Such studies made use of ultrasonic waves to determine the physical and chemical structures of magmatic and sedimentary rocks by measuring the progress velocity of sonic waves in the rock. Said studies, however, mostly worked on sedimentary and magmatic rock specimens, focusing less on metamorphic rocks such as marble due to their anisotropic properties. Understanding the academic literature studies on marble would provide significant contribution to the reduction of production losses during the processing marble blocks in processing plants and the achievement of production efficiency levels that are within economic limits. Within such scope, this study has reviewed the past academic studies on marble, classified them under 6 categories, and comprehensively analyzed each category based on materials, testing setups, test specimens, test parameters and research techniques.展开更多
Indium phosphide(InP)colloidal quantum dots(QDs)have been drawn significant attention as a potentially less toxic alternative to cadmium-based QDs over the past two decades.The advances in their colloidal synthesis me...Indium phosphide(InP)colloidal quantum dots(QDs)have been drawn significant attention as a potentially less toxic alternative to cadmium-based QDs over the past two decades.The advances in their colloidal synthesis methods have allowed for the synthesis of a wide variety of compositions,heterojunctions,dopants,and ligands that enabled spectral tunability from blue to near-infrared,narrow emission linewidths,and perfect quantum yields approaching unity.Furthermore,it has higher covalency compared to cadmium chalcogenides leading to improved optical stability.The state-of-the-art InP QDs with appealing optical and electronic properties have excelled in many applications such as light-emitting diodes,luminescent solar concentrators(LSCs),and solar cells with high potential for commercialization.This review focuses on the history,recent development,and future aspect of synthesis and application of colloidal InP QDs.展开更多
文摘Marble is a metamorphic rock, which is one of the 3 basic rock types (magmatic, sedimentary, metamorphic) forming the earth’s crust. The major characteristic sought after in a rock mass in the field for it to be exportable and usable as marble is its suitability to be cut in blocks. In the process of producing marble slabs from marble blocks, the blocks are expected not to contain potentially problematic hard or weak zones and their geomechanical and chemical properties should conform to the relevant standards. Ignoring of the geological properties of the rock in the process of deciding for marble production at a marble site and determination of production location, direction and method is the most important parameter that would increase production loss. In order to reduce losses by determination of geological properties of marble, many academic studies have been conducted on the effects of water saturation, temperature, freezing and thawing on its mechanical and fracture properties. There are further studies on crack propagation in marble under stress. However, even those marble blocks that are obtained based on geological parameters may suffer serious cracks or fractures due to stresses caused by their weight and geometry. Therefore, cutting direction is of critical importance in order to minimize marble waste in the process of cutting a marble block which is brought to the inventory or processing site with cracks, cavities or fractures. Certain studies exist within such context, where the geometry of the discontinuity within a block is determined using non-destructive methods, such as ultrasonic testing, in order to determine the appropriate cutting direction. Such studies made use of ultrasonic waves to determine the physical and chemical structures of magmatic and sedimentary rocks by measuring the progress velocity of sonic waves in the rock. Said studies, however, mostly worked on sedimentary and magmatic rock specimens, focusing less on metamorphic rocks such as marble due to their anisotropic properties. Understanding the academic literature studies on marble would provide significant contribution to the reduction of production losses during the processing marble blocks in processing plants and the achievement of production efficiency levels that are within economic limits. Within such scope, this study has reviewed the past academic studies on marble, classified them under 6 categories, and comprehensively analyzed each category based on materials, testing setups, test specimens, test parameters and research techniques.
文摘Indium phosphide(InP)colloidal quantum dots(QDs)have been drawn significant attention as a potentially less toxic alternative to cadmium-based QDs over the past two decades.The advances in their colloidal synthesis methods have allowed for the synthesis of a wide variety of compositions,heterojunctions,dopants,and ligands that enabled spectral tunability from blue to near-infrared,narrow emission linewidths,and perfect quantum yields approaching unity.Furthermore,it has higher covalency compared to cadmium chalcogenides leading to improved optical stability.The state-of-the-art InP QDs with appealing optical and electronic properties have excelled in many applications such as light-emitting diodes,luminescent solar concentrators(LSCs),and solar cells with high potential for commercialization.This review focuses on the history,recent development,and future aspect of synthesis and application of colloidal InP QDs.
