本文研究了基于空间向量拟合空间圆直接获取圆心坐标及半径的算法,将该算法应用于空间圆形物体的形态检测与分析。以Microsoft Visual Studio 2008为平台,运用C#编程语言开发了基于PDA的空间圆形物体形态检测与分析系统。以校内混流式...本文研究了基于空间向量拟合空间圆直接获取圆心坐标及半径的算法,将该算法应用于空间圆形物体的形态检测与分析。以Microsoft Visual Studio 2008为平台,运用C#编程语言开发了基于PDA的空间圆形物体形态检测与分析系统。以校内混流式水轮机转子实体模型作为研究对象,结合HP iPAQ移动设备进行实例计算与分析,表明利用该系统可进行水轮机转子空间形态的拟合,进行水轮机转子圆心坐标和半径的计算,完成水轮机转子空间形态的质量评价。研究成果也可为其它空间圆形物体的形态检测工作提供参考。展开更多
Six soluble quinone-amine polymers (PAQs ) were synthesized from p-benzo-quinone with α, ω-diaminoalkoxypolymethylsiloxa, α, ω-diaminopropylpolymethylsiloxa,isophorone diamine, polyether-ester-amide type diamine a...Six soluble quinone-amine polymers (PAQs ) were synthesized from p-benzo-quinone with α, ω-diaminoalkoxypolymethylsiloxa, α, ω-diaminopropylpolymethylsiloxa,isophorone diamine, polyether-ester-amide type diamine and two kinds of disecondary amine,respectively. Their spectral properties and elemental analysis results are reported.展开更多
Both monsoons and westerlies have exerted influence on climate dynamics over the Tibetan Plateau(TP) since the last deglaciation, producing complex patterns of paleohydroclimatic conditions. Diverse proxy records are ...Both monsoons and westerlies have exerted influence on climate dynamics over the Tibetan Plateau(TP) since the last deglaciation, producing complex patterns of paleohydroclimatic conditions. Diverse proxy records are essential to forge a robust understanding of the climate system on the TP. Currently, there is a general lack of understanding of the response of inland lakes over the TP to climate change, especially glacier-fed lakes. Paleohydrological reconstructions of such lakes could deepen our understanding of the history of lake systems and their relationship to regional climate variability. Here we use records of n-alkanes and grain size from the sediments of Bangong Co in the western TP to reconstruct paleohydrological changes over the past 16,000 years. The Paq record(the ratio of non-emergent aquatic macrophytes versus emergent aquatic macrophytes and terrestrial plants) is generally consistent with the variations in summer temperature and precipitation isotopes. The changes in grain-size distributions show a similar trend to Paq but with less pronounced fluctuations in the early-middle Holocene. The new data combined with previous results from the site demonstrate that: 1) Bangong Co experienced relatively large water-level fluctuations during the last deglaciation, with a steadily high lake-level during the early-middle Holocene and a decreasing lake-level in the late Holocene;2) The lake level fluctuations were driven by both high summer temperatures via the melting water and monsoon precipitation. However, the dominant factor controlling lake level changed over time. The lake-level history at Bangong Co deduced from the n-alkanes and grain-size records reveals the past hydrological changes in the catchment area, and stimulates more discussion about the future of glacier-fed lakes under the conditions of unprecedented warming in the region.展开更多
Redox-active organic electrode materials are highly desirable in realizing next-generation all-in-one bendable electronic systems.Herein,a novel flexible supercapacitors(SCs)electrode is fabricated from poly(anthraqui...Redox-active organic electrode materials are highly desirable in realizing next-generation all-in-one bendable electronic systems.Herein,a novel flexible supercapacitors(SCs)electrode is fabricated from poly(anthraquinonyl sulfide)(PAQS)and single-walled carbon nanotubes(SWCNTs)suspension by a simple vacuum filtration and named as PAQS-SWCNTs.The PAQS-SWCNTs electrode offered an initial capacitance of 223 F·g^-1 and outstanding capacitance retention up to 78.4%after 3×10^4 charge-discharge cycles at 0.5 A·g^-1 current density.In a high potential range(0-3 V)and aprotic electrolyte,the PAQS-SWCNTs electrodes in coin cell exhibited an outstanding energy density of 69 Wh·kg^-1 at a power density of 90.6 W·kg^-1,whereas in the fabricated flexible SCs it retained 63.2 Wh·kg^-1.The PAQS-SWCNTs electrodes also showed extraordinary performance at a higher current density(20 A·g^-1)and maintained a specific capacitance of 55 and 47 F·g^-1 for coin and flexible SCs,respectively.Moreover,the flexible SC is further verified to be able to illuminate up multiple LEDs.These futuristic findings showed that the SCs assembled with flexible PAQS-SWCNTs electrodes have potential application in energy-storage devices and make them highly appealing for future redox supercapacitors.展开更多
文摘本文研究了基于空间向量拟合空间圆直接获取圆心坐标及半径的算法,将该算法应用于空间圆形物体的形态检测与分析。以Microsoft Visual Studio 2008为平台,运用C#编程语言开发了基于PDA的空间圆形物体形态检测与分析系统。以校内混流式水轮机转子实体模型作为研究对象,结合HP iPAQ移动设备进行实例计算与分析,表明利用该系统可进行水轮机转子空间形态的拟合,进行水轮机转子圆心坐标和半径的计算,完成水轮机转子空间形态的质量评价。研究成果也可为其它空间圆形物体的形态检测工作提供参考。
文摘Six soluble quinone-amine polymers (PAQs ) were synthesized from p-benzo-quinone with α, ω-diaminoalkoxypolymethylsiloxa, α, ω-diaminopropylpolymethylsiloxa,isophorone diamine, polyether-ester-amide type diamine and two kinds of disecondary amine,respectively. Their spectral properties and elemental analysis results are reported.
基金financially supported by the Natural Science Foundation of China (41601205,41772178,41072120)
文摘Both monsoons and westerlies have exerted influence on climate dynamics over the Tibetan Plateau(TP) since the last deglaciation, producing complex patterns of paleohydroclimatic conditions. Diverse proxy records are essential to forge a robust understanding of the climate system on the TP. Currently, there is a general lack of understanding of the response of inland lakes over the TP to climate change, especially glacier-fed lakes. Paleohydrological reconstructions of such lakes could deepen our understanding of the history of lake systems and their relationship to regional climate variability. Here we use records of n-alkanes and grain size from the sediments of Bangong Co in the western TP to reconstruct paleohydrological changes over the past 16,000 years. The Paq record(the ratio of non-emergent aquatic macrophytes versus emergent aquatic macrophytes and terrestrial plants) is generally consistent with the variations in summer temperature and precipitation isotopes. The changes in grain-size distributions show a similar trend to Paq but with less pronounced fluctuations in the early-middle Holocene. The new data combined with previous results from the site demonstrate that: 1) Bangong Co experienced relatively large water-level fluctuations during the last deglaciation, with a steadily high lake-level during the early-middle Holocene and a decreasing lake-level in the late Holocene;2) The lake level fluctuations were driven by both high summer temperatures via the melting water and monsoon precipitation. However, the dominant factor controlling lake level changed over time. The lake-level history at Bangong Co deduced from the n-alkanes and grain-size records reveals the past hydrological changes in the catchment area, and stimulates more discussion about the future of glacier-fed lakes under the conditions of unprecedented warming in the region.
基金supported by the Ministry of Science and Technology of China(Nos.2016YFF0203803 and 2016YFA020070)the National Natural Science Foundation of China(Nos.51473039 and 21534003)+2 种基金Scientific and Technological Key Project of Shanxi Province(Nos.MC2016-04 and MC2016-08)Natural Science Foundations of Shanxi Province(No.201801D221156)DNL Cooperation Fund of CAS(No.DNL180308)the World Academy of Sciences under the CAS-TWAS PhD President's Fellowship Program.
文摘Redox-active organic electrode materials are highly desirable in realizing next-generation all-in-one bendable electronic systems.Herein,a novel flexible supercapacitors(SCs)electrode is fabricated from poly(anthraquinonyl sulfide)(PAQS)and single-walled carbon nanotubes(SWCNTs)suspension by a simple vacuum filtration and named as PAQS-SWCNTs.The PAQS-SWCNTs electrode offered an initial capacitance of 223 F·g^-1 and outstanding capacitance retention up to 78.4%after 3×10^4 charge-discharge cycles at 0.5 A·g^-1 current density.In a high potential range(0-3 V)and aprotic electrolyte,the PAQS-SWCNTs electrodes in coin cell exhibited an outstanding energy density of 69 Wh·kg^-1 at a power density of 90.6 W·kg^-1,whereas in the fabricated flexible SCs it retained 63.2 Wh·kg^-1.The PAQS-SWCNTs electrodes also showed extraordinary performance at a higher current density(20 A·g^-1)and maintained a specific capacitance of 55 and 47 F·g^-1 for coin and flexible SCs,respectively.Moreover,the flexible SC is further verified to be able to illuminate up multiple LEDs.These futuristic findings showed that the SCs assembled with flexible PAQS-SWCNTs electrodes have potential application in energy-storage devices and make them highly appealing for future redox supercapacitors.
