The northern Guangxi region is an important rare metal, rare earth metal and polymetallic metallogenic province. In the region there exist five metallogenic series and two metallogenic subseries, whose metallogenesis ...The northern Guangxi region is an important rare metal, rare earth metal and polymetallic metallogenic province. In the region there exist five metallogenic series and two metallogenic subseries, whose metallogenesis shows features of polycyclic spiral evolution throughout the geological history. As far as various cycles are concerned, mantle-derived ore substances were reduced while crust-derived ore substances increased from early to late timesfin the whole geological evolutionary history, mantle-derived substances decreased gradually while crust-derived ones increased. Meanwhile ore element associations became more and more varied. In terms of space, mineralization migrated from the old basement outwards, i.e. from west to east during the Precambrian, and from north to south during the Phanerozoic, and again from east to west during the Yanshanian.展开更多
The production cycle of open-cast coal mines generally in eludes drilling, blasting, loading, hauling and coal preparation activities. Individual optimization of these activities does not mean that the whole system is...The production cycle of open-cast coal mines generally in eludes drilling, blasting, loading, hauling and coal preparation activities. Individual optimization of these activities does not mean that the whole system is optimized. This paper proposes a cost model considering all activities in mining cycle and system-wide approach to minimize the total mining cost of bench production. Since the fragmentation size and blast-hole diameter are linked to all activities of mining system, they are considered as decision variables in the problem form ul at io n. The operatio n costs are then minimized by using the evolutionary algorithm. Moreover, the impact of the change in the explosive price, and the hourly unit cost of equipment on total mining cost is quantified by sensitivity analysis. A case study is implemented to demonstrate the developed model.展开更多
Thellungiella salsuginea （halophila） is a close relative of Arabidopsis thaliana but, unlike A. thaliana, it grows well in extreme conditions of cold, salt, and drought as well as nitrogen limitation. Over the last ...Thellungiella salsuginea （halophila） is a close relative of Arabidopsis thaliana but, unlike A. thaliana, it grows well in extreme conditions of cold, salt, and drought as well as nitrogen limitation. Over the last decade, many laboratories have started to use Thellungiella to investigate the physiological, metabolic, and molecular mechanisms of abiotic stress tolerance in plants, and new knowledge has been gained in particular with respect to ion transport and gene expression. The advantage of Thellungiella over other extremophile model plants is that it can be directly compared with Arabidopsis, and therefore generate information on both essential and critical components of stress tolerance. Thellungiella research is supported by a growing body of technical resources comprising physiological and molecular protocols, ecotype collections, expressed sequence tags, cDNA-libraries, microarrays, and a pending genome sequence. This review summarizes the current state of knowledge on Thellungiella and re-evaluates its usefulness as a model for research into plant stress tolerance.展开更多
基金This research was supported by the Chinese Foundation for Development of Geological Science and Technology (Project 49273162)the National Natural Science Foundation of China(Project 49273162)
文摘The northern Guangxi region is an important rare metal, rare earth metal and polymetallic metallogenic province. In the region there exist five metallogenic series and two metallogenic subseries, whose metallogenesis shows features of polycyclic spiral evolution throughout the geological history. As far as various cycles are concerned, mantle-derived ore substances were reduced while crust-derived ore substances increased from early to late timesfin the whole geological evolutionary history, mantle-derived substances decreased gradually while crust-derived ones increased. Meanwhile ore element associations became more and more varied. In terms of space, mineralization migrated from the old basement outwards, i.e. from west to east during the Precambrian, and from north to south during the Phanerozoic, and again from east to west during the Yanshanian.
文摘The production cycle of open-cast coal mines generally in eludes drilling, blasting, loading, hauling and coal preparation activities. Individual optimization of these activities does not mean that the whole system is optimized. This paper proposes a cost model considering all activities in mining cycle and system-wide approach to minimize the total mining cost of bench production. Since the fragmentation size and blast-hole diameter are linked to all activities of mining system, they are considered as decision variables in the problem form ul at io n. The operatio n costs are then minimized by using the evolutionary algorithm. Moreover, the impact of the change in the explosive price, and the hourly unit cost of equipment on total mining cost is quantified by sensitivity analysis. A case study is implemented to demonstrate the developed model.
文摘Thellungiella salsuginea （halophila） is a close relative of Arabidopsis thaliana but, unlike A. thaliana, it grows well in extreme conditions of cold, salt, and drought as well as nitrogen limitation. Over the last decade, many laboratories have started to use Thellungiella to investigate the physiological, metabolic, and molecular mechanisms of abiotic stress tolerance in plants, and new knowledge has been gained in particular with respect to ion transport and gene expression. The advantage of Thellungiella over other extremophile model plants is that it can be directly compared with Arabidopsis, and therefore generate information on both essential and critical components of stress tolerance. Thellungiella research is supported by a growing body of technical resources comprising physiological and molecular protocols, ecotype collections, expressed sequence tags, cDNA-libraries, microarrays, and a pending genome sequence. This review summarizes the current state of knowledge on Thellungiella and re-evaluates its usefulness as a model for research into plant stress tolerance.
