The characteristics and distribution patterns of detrital minerals （0. 063 -0. 125 mm） in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral compo...The characteristics and distribution patterns of detrital minerals （0. 063 -0. 125 mm） in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral composition of 219 surface sediment samples was ana- lysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces ： （Ⅰ） province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; （Ⅱ） middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; （Ⅲ） province west of the Palau--Kyushu Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate - acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau--Kyushu Ridge. it is suggested that, （ 1 ） Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. （2） Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau （e. g. , Benham Plateau） and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. （3） Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.展开更多
Thirty-eight surficial deposit samples were collected from the equatorial North Pacific, and the natural thermoluminescence （TL） characteristics of both bulk and clay fraction samples （ 〈 2μm fractions） were stu...Thirty-eight surficial deposit samples were collected from the equatorial North Pacific, and the natural thermoluminescence （TL） characteristics of both bulk and clay fraction samples （ 〈 2μm fractions） were studied by the FJ427 - AI automatic TL Dosimeter for the first time. With the measurements of clay mineral composition, element composition by XRD and ICP, the correlations between TL intensity and sedimentary environment proxies were analyzed, such as water depth, ratio of FeO to Fe2 O3 contents, LOI, and major clay mineral concentration, and it was found the bulk sample＇ s TL signal was stronger than the clay ones. Usually, increase in the clay components may result in the decrease of TL intensity. From the shape of TL curves, the pelagic sediments can be divided into two groups： the majority group has two glow peaks, in general, the first peak is broad and flat, but the second narrow and sharp; the minority group only has a single peak because the first is absent. The peak centers of TL curves are almost fixed, falling in the temperature sections 230 ~ 260 and 390 ~ 405℃ respectively. Lorentz model packed in the Origin 7.5 was chosen to deal with the TL curves. From the processing results, three parameters （H, C and A ） , corresponding to the height, center, and kurtosis of TL curve, were obtained to describe the curve characteristics. The correlations between TL curve parameters and sedimentary environment proxies were also calculated. On the basis of the above work, the relationship between TL characteristics and sediment type, mineral composition, sedimentary environment of surface sediments was discussed in the study area, and a conclusion is： sediments from the environment of shallower water, higher organic contents and weaker reductivity have stronger TL signals.展开更多
A safety design applies to every stage in a satellite system development life cycle to identify and analyze hazards in the satellite at a system level, eliminating or controlling various safety risks, while verifying ...A safety design applies to every stage in a satellite system development life cycle to identify and analyze hazards in the satellite at a system level, eliminating or controlling various safety risks, while verifying the functions of the satellite system have safety characteristics, so as to optimize the satellite system for the best performance in terms of time and cost. This article comprehensively leverages such factors as satellite reliability, complexity and life cycle by considering the overall satellite safety work plan, hazard analysis, hazard sources, pyrotechnic devices and other module safety critical designs. Safety design measures were formulated to review and verify the effectiveness of system functions including a safe power supply to a satellite and pyrotechnic explosives to achieve the safety requirements of the satellite from a development stage. Safety design activities for each subsystem will ensure meeting the development requirements of the satellite system as a whole, and ensure the satellite system cannot be the cause of casualties, equipment damage, property loss, or have a health-threatening impact or detrimental impact on the environment.展开更多
文摘The characteristics and distribution patterns of detrital minerals （0. 063 -0. 125 mm） in marine sediments provide a significant indicator for the identification of the origin of sediment. The detrital mineral composition of 219 surface sediment samples was ana- lysed to identify the distribution of sediments within the western Philippine Sea. The area can be divided into three mineral provinces ： （Ⅰ） province east of the Philippine Trench, the detrital minerals in this province are mainly composed of calcareous or siliceous organisms, with the addition of volcanogenic minerals from an adjacent island arc; （Ⅱ） middle mineral province, clastic minerals including feldspar, quartz and colorless volcanic glass, sourced from seamounts with intermediate-acid volcanic rock, or erupting intermediate-acid volcano; （Ⅲ） province west of the Palau--Kyushu Ridge, the matter provenance within this province is complex; the small quantity of feldspar and quartz may be sourced from seamounts or erupting volcano with intermediate - acid composition, with a component of volcanic scoria sourced from a volcano erupting on the Palau--Kyushu Ridge. it is suggested that, （ 1 ） Biogenic debris of the study area is closely related to water depth, with the amount of biogenic debris controlled by carbonate lysocline. （2） Volcaniclastic matter derived from the adjacent island arc can be entrained by oceanic currents and transported towards the abyssal basin over a short distance. The weathering products of volcanic rocks of the submarine plateau （e. g. , Benham Plateau） and adjacent ridges provide an important source of detrital sedimentation, and the influence scope of them is constrained by the intensity of submarine weathering. （3） Terrigenous sediments from the continent of Asia and the adjacent Philippine island arc have little influence on the sedimentation of this study area, and the felsic mineral component is probably sourced from volcanic seamounts of intermediate-acid composition.
基金This work was financially supported by the China 0cean Mineral Resources Research and Development Association under contract No.DY105-01-03-02the National Natural Science Foundation of China under contract No.49776295.
文摘Thirty-eight surficial deposit samples were collected from the equatorial North Pacific, and the natural thermoluminescence （TL） characteristics of both bulk and clay fraction samples （ 〈 2μm fractions） were studied by the FJ427 - AI automatic TL Dosimeter for the first time. With the measurements of clay mineral composition, element composition by XRD and ICP, the correlations between TL intensity and sedimentary environment proxies were analyzed, such as water depth, ratio of FeO to Fe2 O3 contents, LOI, and major clay mineral concentration, and it was found the bulk sample＇ s TL signal was stronger than the clay ones. Usually, increase in the clay components may result in the decrease of TL intensity. From the shape of TL curves, the pelagic sediments can be divided into two groups： the majority group has two glow peaks, in general, the first peak is broad and flat, but the second narrow and sharp; the minority group only has a single peak because the first is absent. The peak centers of TL curves are almost fixed, falling in the temperature sections 230 ~ 260 and 390 ~ 405℃ respectively. Lorentz model packed in the Origin 7.5 was chosen to deal with the TL curves. From the processing results, three parameters （H, C and A ） , corresponding to the height, center, and kurtosis of TL curve, were obtained to describe the curve characteristics. The correlations between TL curve parameters and sedimentary environment proxies were also calculated. On the basis of the above work, the relationship between TL characteristics and sediment type, mineral composition, sedimentary environment of surface sediments was discussed in the study area, and a conclusion is： sediments from the environment of shallower water, higher organic contents and weaker reductivity have stronger TL signals.
文摘A safety design applies to every stage in a satellite system development life cycle to identify and analyze hazards in the satellite at a system level, eliminating or controlling various safety risks, while verifying the functions of the satellite system have safety characteristics, so as to optimize the satellite system for the best performance in terms of time and cost. This article comprehensively leverages such factors as satellite reliability, complexity and life cycle by considering the overall satellite safety work plan, hazard analysis, hazard sources, pyrotechnic devices and other module safety critical designs. Safety design measures were formulated to review and verify the effectiveness of system functions including a safe power supply to a satellite and pyrotechnic explosives to achieve the safety requirements of the satellite from a development stage. Safety design activities for each subsystem will ensure meeting the development requirements of the satellite system as a whole, and ensure the satellite system cannot be the cause of casualties, equipment damage, property loss, or have a health-threatening impact or detrimental impact on the environment.
