The population of the intertidal gastropod Littorina saxcailis from Laxey estuary in the Isle of Man is exposed to mine-related contamination of Zn （and is tolerant to Zn and Pb） compared to those of Castletown, Der...The population of the intertidal gastropod Littorina saxcailis from Laxey estuary in the Isle of Man is exposed to mine-related contamination of Zn （and is tolerant to Zn and Pb） compared to those of Castletown, Derbyhaven, Peel and Ramsey. Tolerances to salinity and desiccation stress were assayed to test how metal tolerance could affect tolerance to general stress. The winkles were experimentally exposed to salinities of 0, 17 and 60 practical salinity units （psu） with 34 psu as control. Desiccation stress was determined by aerial exposure of the winkles at 24℃. No control mortalities were recorded and mortalities in 17 psu were less than 50% for all populations over a 24-day exposure period. LT50 values （mean±SD, n=5） at 0 psu ranged from 6.6 ± 0.6 to 7.5 ± 1.3 d for winkles from Ramsey and Laxey respectively. The values for 60 psu ranged from 7.0±0.7 to 8.4±0.9 d. No significant differences in LT50 values were obtained for the salinity exposurcs（ANOVA,P〉0.05） but there was a significant difference in tolerance to desiccation （P〈0.01）. The winkles from Laxey showed very high susceptibility to desiccation stress probably indicating a physiological trade-off to metal tolerance.展开更多
1 The Fair Isle sweater,a timeless fashion element,continues to charm the world.This comfortable,colorful knit has grown from a practical workwear piece into a high-fashion item beloved by the royal family,celebrities...1 The Fair Isle sweater,a timeless fashion element,continues to charm the world.This comfortable,colorful knit has grown from a practical workwear piece into a high-fashion item beloved by the royal family,celebrities and even the latest fashion designers.Despite its long history,the Fair Isle sweater remains popular,especially as winter approaches.展开更多
CAETE serves as an apt venue for African businesses to boost exports,form lasting links In the picturesque city of Changsha,a cool breeze from the Xiangjiang River whispers through landmarks like Yuelu Mountain and Or...CAETE serves as an apt venue for African businesses to boost exports,form lasting links In the picturesque city of Changsha,a cool breeze from the Xiangjiang River whispers through landmarks like Yuelu Mountain and Orange Isle.Inside the exhibition halls,the rich aromas of African tea,spices,and essential oils filled the air,as a renowned showcase of China-Africa cooperation brands got underway.展开更多
In this paper,we present a novel unimodular sequence design algorithm based on the coordinate descent(CD)algorithm,aimed at countering electronic surveillance(ES)systems based on cyclostationary analysis.Our algorithm...In this paper,we present a novel unimodular sequence design algorithm based on the coordinate descent(CD)algorithm,aimed at countering electronic surveillance(ES)systems based on cyclostationary analysis.Our algorithm not only provides resistance against cyclostationary analysis(CSA)but also maintains low integrated sidelobe(ISL)characteristics.Initially,we derive the expression of the cyclostationary feature(CSF)detector and simplify it into an iterative quadratic form.Additionally,we derive a quadratic form to ensure the similarity of the autocorrelation sidelobes.To balance the minimization of the detection probability and the ISL values,we introduce a Pareto scalar that transforms the multiobjective optimization problem into a convex combination of objective functions.This approach allows us to find an optimal trade-off between the two objectives.Finally,we propose a monotonic algorithm based on the CD algorithm to counter CSA analysis.This algorithm efficiently solves the optimization problem mentioned earlier.Numerical experiments are conducted to validate the correctness and effectiveness of our proposed algorithm.展开更多
Byron＇s literary fortune in China starts with the debut of ＂The Isles of Greece＂ in the opening of the twentieth century. Even though such reading proves to be deliberate misreading, no serious effort has been made...Byron＇s literary fortune in China starts with the debut of ＂The Isles of Greece＂ in the opening of the twentieth century. Even though such reading proves to be deliberate misreading, no serious effort has been made so far to explore the contextual ambiguities of the poem with particular regard to the identity of the singer. In this paper, I intend to take three steps to discuss how the identity of the singer varies with the context and how his shifting identity affects the meaning of the lyric. As a rich locus of historicity, ＂The Isles of Greece,＂ together with its preamble and its concluding notes, may project up multiple layers of a romantic cosmos ; and its reading in China is a typical example of ＂culture in action. ＂展开更多
The Tian Qin space-borne gravitational wave detector will orbit at an altitude of1.0×10^(5)km with an arm length of 1.7×10^(5)km,structured in an equilateral triangular satellite formation.The Tian Qin proje...The Tian Qin space-borne gravitational wave detector will orbit at an altitude of1.0×10^(5)km with an arm length of 1.7×10^(5)km,structured in an equilateral triangular satellite formation.The Tian Qin project delineates detailed requirements for orbit determination during both the launch phase and subsequent scientific experimentation.This paper pioneers the investigation of Precise Orbit Determination(POD)for Tian Qin utilizing the third generation of Bei Dou global navigation satellite system(BDS-3)Inter-Satellite Link(ISL)through simulation.By analyzing the visibility,the feasibility of using BDS-3 ISLs for Tian Qin POD is explored.Furthermore,a refined Solar Radiation Pressure(SRP)model is developed,and the POD accuracy of Tian Qin is assessed,considering factors such as arc length,ranging intervals,and error sources.The results indicate the following:(A)Visibility between Tian Qin and BDS-3 satellites is intermittent,with an average of 10.6 BDS-3 satellites visible to Tian Qin,and the average Root Mean Square(RMS)-value of Position Dilution of Precision(PDOP)for Tian Qin is 48.13.(B)POD accuracy improves with shorter ranging intervals.(C)The error in ephemeris is the dominant factor affecting the POD accuracy.(D)The establishment of three links between Tian Qin and the BDS-3 satellites satisfies the POD requirements of Tian Qin.With a ranging interval of 600 s and over a 7-day arc,the average three-Dimensional(3D)position accuracy of the three Tian Qin satellites is 1.35 m,while the 3D velocity accuracy is 0.08 mm/s.展开更多
The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one o...The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing stability.In this paper,we propose an improved scheme for connection-oriented routing strategy named the Minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route oscillations.The simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.展开更多
基金TheCom m onwealthU niversitiesCom m issionintheU nitedK ingdom
文摘The population of the intertidal gastropod Littorina saxcailis from Laxey estuary in the Isle of Man is exposed to mine-related contamination of Zn （and is tolerant to Zn and Pb） compared to those of Castletown, Derbyhaven, Peel and Ramsey. Tolerances to salinity and desiccation stress were assayed to test how metal tolerance could affect tolerance to general stress. The winkles were experimentally exposed to salinities of 0, 17 and 60 practical salinity units （psu） with 34 psu as control. Desiccation stress was determined by aerial exposure of the winkles at 24℃. No control mortalities were recorded and mortalities in 17 psu were less than 50% for all populations over a 24-day exposure period. LT50 values （mean±SD, n=5） at 0 psu ranged from 6.6 ± 0.6 to 7.5 ± 1.3 d for winkles from Ramsey and Laxey respectively. The values for 60 psu ranged from 7.0±0.7 to 8.4±0.9 d. No significant differences in LT50 values were obtained for the salinity exposurcs（ANOVA,P〉0.05） but there was a significant difference in tolerance to desiccation （P〈0.01）. The winkles from Laxey showed very high susceptibility to desiccation stress probably indicating a physiological trade-off to metal tolerance.
文摘1 The Fair Isle sweater,a timeless fashion element,continues to charm the world.This comfortable,colorful knit has grown from a practical workwear piece into a high-fashion item beloved by the royal family,celebrities and even the latest fashion designers.Despite its long history,the Fair Isle sweater remains popular,especially as winter approaches.
文摘CAETE serves as an apt venue for African businesses to boost exports,form lasting links In the picturesque city of Changsha,a cool breeze from the Xiangjiang River whispers through landmarks like Yuelu Mountain and Orange Isle.Inside the exhibition halls,the rich aromas of African tea,spices,and essential oils filled the air,as a renowned showcase of China-Africa cooperation brands got underway.
基金support of the National Natural Science Foundation of China under grant numbers 62101570 and 61901494financial support has played a crucial role in the successful completion of this research.
文摘In this paper,we present a novel unimodular sequence design algorithm based on the coordinate descent(CD)algorithm,aimed at countering electronic surveillance(ES)systems based on cyclostationary analysis.Our algorithm not only provides resistance against cyclostationary analysis(CSA)but also maintains low integrated sidelobe(ISL)characteristics.Initially,we derive the expression of the cyclostationary feature(CSF)detector and simplify it into an iterative quadratic form.Additionally,we derive a quadratic form to ensure the similarity of the autocorrelation sidelobes.To balance the minimization of the detection probability and the ISL values,we introduce a Pareto scalar that transforms the multiobjective optimization problem into a convex combination of objective functions.This approach allows us to find an optimal trade-off between the two objectives.Finally,we propose a monotonic algorithm based on the CD algorithm to counter CSA analysis.This algorithm efficiently solves the optimization problem mentioned earlier.Numerical experiments are conducted to validate the correctness and effectiveness of our proposed algorithm.
文摘Byron＇s literary fortune in China starts with the debut of ＂The Isles of Greece＂ in the opening of the twentieth century. Even though such reading proves to be deliberate misreading, no serious effort has been made so far to explore the contextual ambiguities of the poem with particular regard to the identity of the singer. In this paper, I intend to take three steps to discuss how the identity of the singer varies with the context and how his shifting identity affects the meaning of the lyric. As a rich locus of historicity, ＂The Isles of Greece,＂ together with its preamble and its concluding notes, may project up multiple layers of a romantic cosmos ; and its reading in China is a typical example of ＂culture in action. ＂
基金co-supported by the Guangdong Major Project of Basic and Applied Basic Research,China(No.2019B030302001)the Guangdong Basic and Applied Basic Research Foundation,China(No.2022A1515110236)the Fundamental Research Funds for the Central Universities,Sun Yat-Sen University,China(No.23xkjc001)。
文摘The Tian Qin space-borne gravitational wave detector will orbit at an altitude of1.0×10^(5)km with an arm length of 1.7×10^(5)km,structured in an equilateral triangular satellite formation.The Tian Qin project delineates detailed requirements for orbit determination during both the launch phase and subsequent scientific experimentation.This paper pioneers the investigation of Precise Orbit Determination(POD)for Tian Qin utilizing the third generation of Bei Dou global navigation satellite system(BDS-3)Inter-Satellite Link(ISL)through simulation.By analyzing the visibility,the feasibility of using BDS-3 ISLs for Tian Qin POD is explored.Furthermore,a refined Solar Radiation Pressure(SRP)model is developed,and the POD accuracy of Tian Qin is assessed,considering factors such as arc length,ranging intervals,and error sources.The results indicate the following:(A)Visibility between Tian Qin and BDS-3 satellites is intermittent,with an average of 10.6 BDS-3 satellites visible to Tian Qin,and the average Root Mean Square(RMS)-value of Position Dilution of Precision(PDOP)for Tian Qin is 48.13.(B)POD accuracy improves with shorter ranging intervals.(C)The error in ephemeris is the dominant factor affecting the POD accuracy.(D)The establishment of three links between Tian Qin and the BDS-3 satellites satisfies the POD requirements of Tian Qin.With a ranging interval of 600 s and over a 7-day arc,the average three-Dimensional(3D)position accuracy of the three Tian Qin satellites is 1.35 m,while the 3D velocity accuracy is 0.08 mm/s.
基金supported by the National Key Research and Development Program of China(No.2020YFB1806000)。
文摘The high-speed movement of satellites makes it not feasible to directly apply the mature routing scheme on the ground to the satellite network.DT-DVTR in the snapshot-based connectionoriented routing strategy is one of the representative solutions,but it still has room for improvement in terms of routing stability.In this paper,we propose an improved scheme for connection-oriented routing strategy named the Minimal Topology Change Routing based on Collaborative Rules(MTCR-CR).The MTCR-CR uses continuous time static topology snapshots based on satellite status to search for intersatellite link(ISL)construction solutions that meet the minimum number of topology changes to avoid route oscillations.The simulation results in Beidou-3 show that compared with DT-DVTR,MTCR-CR reduces the number of routing changes by about 92%,the number of path changes caused by routing changes is about38%,and the rerouting time is reduced by approximately 47%.At the same time,in order to show our algorithm more comprehensively,the same experimental index test was also carried out on the Globalstar satellite constellation.
