The Spanish Central System(SCS)contains several suites of Palaeozoic mafic igneous intrusions with contrasting geochemical affinity:Ordovician tholeiitic metabasites,Variscan calc-alkaline gabbros(Gb1)and microdiorite...The Spanish Central System(SCS)contains several suites of Palaeozoic mafic igneous intrusions with contrasting geochemical affinity:Ordovician tholeiitic metabasites,Variscan calc-alkaline gabbros(Gb1)and microdiorites(Gb2),shoshonitic monzogabbros(Gb3)and alkaline diabases and lamprophyres(Gb4).Not all of these rocks are accurately dated,and several aspects of their genesis are still poorly understood.We present new whole-rock geochemical data(major and trace elements,and Sr-Nd isotopes),U-Pb and Lu-Hf isotopic ratios on magmatic zircons and 40 Ar/39Ar amphibole geochronology results in order to establish a precise chronology for the successive events of magmatism in the SCS,and discuss the nature of their mantle sources.Accurate ages have been determined for the Variscan gabbros(305-294 Ma),the microdiorites(299 Ma)and the accompanying felsic porphyries(292 Ma),the shoshonitic monzogabbros(285 Ma),and the alkaline diabases(274 Ma)and monzosyenites(271-264 Ma).According to this information,the Variscan mafic magmatism would be mainly concentrated in the range of 305-294 Ma,with a final manifestation represented by the minor shoshonitic dykes.The alkaline magmatism proved to be slightly older than previously thought and yielded at least two distinct pulses:diabases and lamprophyres-monzosyenites.Zircon Hf isotopes evidence the involvement of depleted and slightly enriched mantle sources.The bulk of the eHf values are in the broad range of-8 to+11,indicative of melting both depleted and enriched mantle regions.The high within-sample Hf isotope variation(up to-11 epsilon units)shown by samples from the Variscan series(gabbros,microdiorites and monzogabbros)could be explained mainly by hybridisation of magmas derived from heterogeneous lithospheric mantle sources.Pressure estimates indicate that the Variscan mafic magmas were extracted from the lithosphere.The Nd-Hf isotopic composition of these suites of rocks suggests the recycling of pelitic sediments during the Cadomian orogeny.Deeper(asthenospheric)mantle levels were involved in the generation of the alkaline suite,whose anomalous negative eHf values(moderately decoupled with respect to radiogenic Nd)could be associated with subducted oceanic components raised by mantle upwelling associated with lithosphere thinning and extension during the Permian.展开更多
The perihelion of long-period comets places them near the Sun so they may exhibit activity.Before 2013 LU28 reached its perihelion,we performed a continuous observation to detect possible activity.Using the Lijiang 2....The perihelion of long-period comets places them near the Sun so they may exhibit activity.Before 2013 LU28 reached its perihelion,we performed a continuous observation to detect possible activity.Using the Lijiang 2.4 m telescope with a Johnson R filter,we measured the brightness of 2013 LU28 from 2024 January 3 to April 13.The instrumental magnitudes were subsequently transformed into the Pan-STARRS r system.Due to the noticeable descending trend in the absolute magnitude,we verified the cometary activity and constrained some photometric properties of 2013 LU28.Consequently,the increased cross-sectional area had a rate of 42.8 km^(2)day^(−1),and the corresponding mass-loss rate was 2.64 kg s^(−1)with the assumption of a dust-particle size a=10 mm and the densityρ=400 kg m^(−3).We estimated the nucleus radius as 0.11■r_(n)■0.21 km for CO sublimation and 0.20■r_(n)■0.71 km for CO_(2)sublimation and the grain size of 2013 LU28 was ac;117.95μm for CO and ac■7.57μm for CO_(2).The long-term observations provided in this paper will offer significant value for investigating the mechanisms driving the activity of 2013 LU28.展开更多
This paper explores the divergent receptions of Lu Xun in China and the Anglophone world,examining how his image has been constructed,exalted,and contested across ideological and cultural boundaries.In China,Lu Xun is...This paper explores the divergent receptions of Lu Xun in China and the Anglophone world,examining how his image has been constructed,exalted,and contested across ideological and cultural boundaries.In China,Lu Xun is revered as a literary saint and revolutionary prophet,with his contributions to the New Culture Movement and critiques of feudalism canonized in public memory.In contrast,Anglophone scholarship has deconstructed his figure,focusing on translation politics,Cold War anxieties,postcolonial theory,and aesthetic modernism.Western critics have examined his ethical ambiguities,ideological complexities,and the aesthetic tensions in his work.This comparative analysis highlights how Lu Xun’s legacy reflects both the complexity of his work and the cultural,theoretical,and political contexts of his interpreters.展开更多
To examine how low-temperature frost affects tea production in the Dabie Mountains by using Lu an Guapian tea plants as the study material,four groups of temperature treatments were applied in an artificial climate ch...To examine how low-temperature frost affects tea production in the Dabie Mountains by using Lu an Guapian tea plants as the study material,four groups of temperature treatments were applied in an artificial climate chamber to conduct controlled low-temperature experiments,and measurements of leaf photosynthetic and chlorophyll fluorescence parameters were taken to assess the effects of varying low temperatures on photosynthetic performance and fluorescence characteristics.The results show that all low-temperature conditions cause visible leaf damage,with young leaves exhibiting greater sensitivity than mature leaves,and colder temperatures lead to more severe injury.Low temperatures also reduce photosynthetic capacity and fluorescence indicators,and the magnitude of these effects increases as temperature decreases.These impacts ultimately hinder plant growth and negatively affect tea yield and quality.展开更多
快速求解线性方程组是电磁场、流体力学、结构力学等许多工程问题的核心,LU分解是求解稠密线性方程组最常用的方法之一。该文详细描述了LU分解的原理和过程,基于此过程的特点,在CUDA (Compute Unified Device Architecture)并行环境下,...快速求解线性方程组是电磁场、流体力学、结构力学等许多工程问题的核心,LU分解是求解稠密线性方程组最常用的方法之一。该文详细描述了LU分解的原理和过程,基于此过程的特点,在CUDA (Compute Unified Device Architecture)并行环境下,提出一种的并行计算方法,该方法可以将计算任务划分为若干小问题进行求解,各部分求解完成后再通过前向回代和后向回代,即可获得最终解。最后通过实验证明,该方法能够充分利用GPU,有效地减少了数据间的通信开销,从而加快了求解速度,提高了计算效率。Rapid solving of linear systems is central to engineering challenges in electromagnetics, fluid dynamics, structural mechanics, and more. LU decomposition remains one of the most widely used methods for dense linear systems. This paper elaborates on the principles and process of LU decomposition. Leveraging its algorithmic characteristics, we propose a parallel computation framework on CUDA that decomposes the computational task into smaller sub-problems. After solving these sub-tasks independently, the final solution is reconstructed through forward and backward substitutions. Experimental results demonstrate that this method maximizes GPU utilization, significantly reduces inter-node communication overhead, and achieves accelerated solving speeds with improved computational efficiency.展开更多
基金supported by the CGL2016-78796 project of the Ministerio de Economiay Competitividad of Spain and the UCM Research Group 2018/19 n°910492。
文摘The Spanish Central System(SCS)contains several suites of Palaeozoic mafic igneous intrusions with contrasting geochemical affinity:Ordovician tholeiitic metabasites,Variscan calc-alkaline gabbros(Gb1)and microdiorites(Gb2),shoshonitic monzogabbros(Gb3)and alkaline diabases and lamprophyres(Gb4).Not all of these rocks are accurately dated,and several aspects of their genesis are still poorly understood.We present new whole-rock geochemical data(major and trace elements,and Sr-Nd isotopes),U-Pb and Lu-Hf isotopic ratios on magmatic zircons and 40 Ar/39Ar amphibole geochronology results in order to establish a precise chronology for the successive events of magmatism in the SCS,and discuss the nature of their mantle sources.Accurate ages have been determined for the Variscan gabbros(305-294 Ma),the microdiorites(299 Ma)and the accompanying felsic porphyries(292 Ma),the shoshonitic monzogabbros(285 Ma),and the alkaline diabases(274 Ma)and monzosyenites(271-264 Ma).According to this information,the Variscan mafic magmatism would be mainly concentrated in the range of 305-294 Ma,with a final manifestation represented by the minor shoshonitic dykes.The alkaline magmatism proved to be slightly older than previously thought and yielded at least two distinct pulses:diabases and lamprophyres-monzosyenites.Zircon Hf isotopes evidence the involvement of depleted and slightly enriched mantle sources.The bulk of the eHf values are in the broad range of-8 to+11,indicative of melting both depleted and enriched mantle regions.The high within-sample Hf isotope variation(up to-11 epsilon units)shown by samples from the Variscan series(gabbros,microdiorites and monzogabbros)could be explained mainly by hybridisation of magmas derived from heterogeneous lithospheric mantle sources.Pressure estimates indicate that the Variscan mafic magmas were extracted from the lithosphere.The Nd-Hf isotopic composition of these suites of rocks suggests the recycling of pelitic sediments during the Cadomian orogeny.Deeper(asthenospheric)mantle levels were involved in the generation of the alkaline suite,whose anomalous negative eHf values(moderately decoupled with respect to radiogenic Nd)could be associated with subducted oceanic components raised by mantle upwelling associated with lithosphere thinning and extension during the Permian.
基金Funding for the telescope has been provided by CAS and the People’s Government of Yunnan Provincefunded by the Civil Aerospace pre-research project D020302+2 种基金National Natural Science Foundation of China (U12150009,12150009)the CAS Light of West China Programthe science research grants from the China Manned Space Project with NO.CMS-CSST-2021-B10
文摘The perihelion of long-period comets places them near the Sun so they may exhibit activity.Before 2013 LU28 reached its perihelion,we performed a continuous observation to detect possible activity.Using the Lijiang 2.4 m telescope with a Johnson R filter,we measured the brightness of 2013 LU28 from 2024 January 3 to April 13.The instrumental magnitudes were subsequently transformed into the Pan-STARRS r system.Due to the noticeable descending trend in the absolute magnitude,we verified the cometary activity and constrained some photometric properties of 2013 LU28.Consequently,the increased cross-sectional area had a rate of 42.8 km^(2)day^(−1),and the corresponding mass-loss rate was 2.64 kg s^(−1)with the assumption of a dust-particle size a=10 mm and the densityρ=400 kg m^(−3).We estimated the nucleus radius as 0.11■r_(n)■0.21 km for CO sublimation and 0.20■r_(n)■0.71 km for CO_(2)sublimation and the grain size of 2013 LU28 was ac;117.95μm for CO and ac■7.57μm for CO_(2).The long-term observations provided in this paper will offer significant value for investigating the mechanisms driving the activity of 2013 LU28.
文摘This paper explores the divergent receptions of Lu Xun in China and the Anglophone world,examining how his image has been constructed,exalted,and contested across ideological and cultural boundaries.In China,Lu Xun is revered as a literary saint and revolutionary prophet,with his contributions to the New Culture Movement and critiques of feudalism canonized in public memory.In contrast,Anglophone scholarship has deconstructed his figure,focusing on translation politics,Cold War anxieties,postcolonial theory,and aesthetic modernism.Western critics have examined his ethical ambiguities,ideological complexities,and the aesthetic tensions in his work.This comparative analysis highlights how Lu Xun’s legacy reflects both the complexity of his work and the cultural,theoretical,and political contexts of his interpreters.
基金Supported by the Key Projects in Natural Science Research at the University Level of West Anhui College (WXZR202212).
文摘To examine how low-temperature frost affects tea production in the Dabie Mountains by using Lu an Guapian tea plants as the study material,four groups of temperature treatments were applied in an artificial climate chamber to conduct controlled low-temperature experiments,and measurements of leaf photosynthetic and chlorophyll fluorescence parameters were taken to assess the effects of varying low temperatures on photosynthetic performance and fluorescence characteristics.The results show that all low-temperature conditions cause visible leaf damage,with young leaves exhibiting greater sensitivity than mature leaves,and colder temperatures lead to more severe injury.Low temperatures also reduce photosynthetic capacity and fluorescence indicators,and the magnitude of these effects increases as temperature decreases.These impacts ultimately hinder plant growth and negatively affect tea yield and quality.
文摘快速求解线性方程组是电磁场、流体力学、结构力学等许多工程问题的核心,LU分解是求解稠密线性方程组最常用的方法之一。该文详细描述了LU分解的原理和过程,基于此过程的特点,在CUDA (Compute Unified Device Architecture)并行环境下,提出一种的并行计算方法,该方法可以将计算任务划分为若干小问题进行求解,各部分求解完成后再通过前向回代和后向回代,即可获得最终解。最后通过实验证明,该方法能够充分利用GPU,有效地减少了数据间的通信开销,从而加快了求解速度,提高了计算效率。Rapid solving of linear systems is central to engineering challenges in electromagnetics, fluid dynamics, structural mechanics, and more. LU decomposition remains one of the most widely used methods for dense linear systems. This paper elaborates on the principles and process of LU decomposition. Leveraging its algorithmic characteristics, we propose a parallel computation framework on CUDA that decomposes the computational task into smaller sub-problems. After solving these sub-tasks independently, the final solution is reconstructed through forward and backward substitutions. Experimental results demonstrate that this method maximizes GPU utilization, significantly reduces inter-node communication overhead, and achieves accelerated solving speeds with improved computational efficiency.
