From the Industrial Revolution to the World War,the past three centuries have witnessed the development and rise and fall of Great Britain.Great Britain,an island country with a total area of about 240,000 square kilo...From the Industrial Revolution to the World War,the past three centuries have witnessed the development and rise and fall of Great Britain.Great Britain,an island country with a total area of about 240,000 square kilometers,enjoys a very important place in the world in modern history.Great Britain was the first industrial country and created the epoch-making laissez-faire capitalism and built a sun-never-set empire.It was also the leadership of the world from the middle of 18^th and to the middle of 19^th century.In retrospect to the rise of Great Britain,we can easily see that it was by relying on an innovative culture that the island country became a great power in Europe and then became the dominant empire in the world.This innovative character permeates in all kinds of culture including industrial,military,technological,politic and diplomatic.As for the main cause of Great Britain’s rise,this thesis attempts to analyze from three aspects,that is,the emancipation of mind,the advancement of military power,and the development of technology.After the World War,Great Britain began to suffer a decline in status and was reduced to a second class developed country.That is also because the conservative factor in its culture which blocks its development and the potential to innovate new things.The past years has witnessed the fall of the empire and also left us much inspiration.Take the history as a mirror,the thesis will focus on the“English disease”and influence of the World War to make an analysis on Great Britain’s fall.A conclusion of inspiration would also be included.展开更多
The novel The Rise and Fall of Wing Shing Street delves into the reality of Hong Kong residents deeply attuned to spatial awareness but detached from temporal significance,entangling emotions surrounding time and spac...The novel The Rise and Fall of Wing Shing Street delves into the reality of Hong Kong residents deeply attuned to spatial awareness but detached from temporal significance,entangling emotions surrounding time and space.Through narrative interruption and extension,the author portrays the genuine struggles of Hong Kong inhabitants-juxtaposing the blurred boundaries of time and space and the inherent rootlessness of reality within a fictionalized framework.Emphasizing the 20th-century human condition,wherein spatial awareness overshadows temporal understanding,the novel underscores the consequences:a loss of history and cultural identity.With a fresh perspective,the narrative explores the interplay of time and space,accentuating both the fictitious and authentic dimensions.This prompts readers to reconsider their history,culture,and the current moment,ultimately highlighting the pivotal role of temporal awareness.展开更多
This paper examines various aspects of the design process and subsequent field test measurements of a large and complex substation grounding system. The study and measurements show that soil layering and lead interfer...This paper examines various aspects of the design process and subsequent field test measurements of a large and complex substation grounding system. The study and measurements show that soil layering and lead interference can have a significant impact on the appropriate test location that yields the exact substation ground impedance. Applying a specific percentage rule such as the 61.8% rule for uniform soils to obtain the true ground impedance may lead to unacceptable errors for large grounding systems. This poses significant problems when attempting to validate a design based on raw test data that are interpreted using approximate methods to evaluate substation ground impedance, and determine ground potential rise (GPR), touch and step voltages. Advanced measurement methodologies and modern software packages were used to obtain and effectively analyze fall of potential test data, compute fault current distribution, and evaluate touch and step voltages for this large substation. Fault current distribution between the grounding system and other metallic paths were computed to determine the portion of fault current discharged in the grounding system. The performance of the grounding system, including its GPR and touch and step voltages, has been accurately computed and measured, taking into account the impedance of the steel material used of the ground conductors and circulating currents within the substation grounding system.展开更多
The controlling and influencing effects of the joint action of plates surrounding China on strong earthquakes in Chinese mainland are discussed, and the characteristics of seismic activities in the West of China and n...The controlling and influencing effects of the joint action of plates surrounding China on strong earthquakes in Chinese mainland are discussed, and the characteristics of seismic activities in the West of China and neighboring regions are further studied. The results show that the seismic activity in the West of China and neighboring regions not only has the characteristics of high tide and low tide alternation but also has the characteristics of rising in one region while falling in another, and the rise and fall of seismicity are in some proportion. The above characteristics are useful for the prediction of main body region of strong earthquakes in Chinese mainland, especially for the judgement of the ending time of the high tide period.展开更多
The idea of this study is derived from observing the profitability of stock investments following the phenomena of continuously rising(or falling)prices of stocks and continuously overbought(or oversold)signals emitte...The idea of this study is derived from observing the profitability of stock investments following the phenomena of continuously rising(or falling)prices of stocks and continuously overbought(or oversold)signals emitted by technical indicators.We employ the standard event study approach and technical trading strategies to explore whether investors would exploit profits in trading the constituent stocks of the Korea Composite Stock Price Index 50 and Shanghai Stock Exchange 50 when the aforementioned continuous phenomena occur.We find that both the Korean and Chinese stock markets are not fully efficient;this finding may enhance the robustness of the existing literature.In addition,we reveal that contrarian strategies are appropriate for the trading stocks listed on the Korean stock market for all the cases investigated in this study.However,momentum strategies are appropriate for the Chinese stock market when continuously rising stock prices and overbought signals are simultaneously observed.These findings imply that the difference in investor behaviors between the Korean and Chinese stock markets might result in dissimilar trading strategies being employed for these two markets.展开更多
A nonlinear two-dimension dynamic model of storm surge (SS) and astronomical tide(AT) was used to investigate the effects of SS and AT on expected sea level rise (SLR) at principalcoastal stations in the Shanghai regi...A nonlinear two-dimension dynamic model of storm surge (SS) and astronomical tide(AT) was used to investigate the effects of SS and AT on expected sea level rise (SLR) at principalcoastal stations in the Shanghai region and to estimate numerically the probable maximum water lerel for2010 - 2050. Evidence suggests tha SLR causes reduction of SS; that its influence on SS depends on theintensity and path of a tropical cyclone and the station locality; tha the SLR’s effects on AT vary periodi-cally, with the peried being the same as tha of the AT’s: and that as the SLR increment grows, its impactincreases; below mean sea level (MSL) the effect is positive at rising tide and negative at ebb tide, andvice versa for the effect above MSL. Study of the probable maximum water level (by assuming SLR, SSalong favorable tropical cyclone’s path, its possible maximum intensity and effectivee spring AT at a rangeof set paths of Cyclones 5612, 8114, 9417) showed that the probable maximum water level is 740, 745,and 751 cm in the years 2010, 2030, and 2050, respetively, over the target region.展开更多
During the Tang Dynasty,the land of Shu was composed of the Ba and Shu areas,which were adjacent to present-day Hanzhong city of Shaanxi province to the north,northern Yunnan province to the south,Wushan county of Cho...During the Tang Dynasty,the land of Shu was composed of the Ba and Shu areas,which were adjacent to present-day Hanzhong city of Shaanxi province to the north,northern Yunnan province to the south,Wushan county of Chongqing to the east,and Xichang city of Sichuan province to the west.In the nearly 300 years of rule under the dynasty,a number of poets,whether they were born or just worked and lived there for a short period of time,wrote many immortal poems,which constitute an integral part of Tang poetry.They range from Chen Zi’ang and Wang Bo of the early Tang to Li Shangyin,Wen Tingyun,and Wei Zhuang of the late Tang.The land of Shu is,therefore,the witness of the rise and fall of Tang poetry.展开更多
Tide gauge data from 1950 to 2015 are used to analyze sea level change, tidal change, return levels, and design tide levels under rising sea level scenarios in Bohai Bay. Results show the following: 1) Since 1950 sea ...Tide gauge data from 1950 to 2015 are used to analyze sea level change, tidal change, return levels, and design tide levels under rising sea level scenarios in Bohai Bay. Results show the following: 1) Since 1950 sea levels in Bohai Bay show a significant rising trend of 3.3 mm per year. The speed has been particularly rapid in 1980e2015 at a rate of 4.7 mm per year. 2) Astronomical tides showed a clear long-term trend in 1950e2015. The amplitude and phase lag of the M2 tide constituent decreased at a rate of 0.21 cm per year and 0.11 per year, respectively and the phase lag of K1 decreased at a rate of 0.09 per year, whereas there was little change in its amplitude. The mean high and low tides increased at a rate of 0.08 and 0.52 cm per year, respectively, whereas the mean tidal range decreased at a rate of 0.44 cm per year. Results from numerical experiments show that local sea level rise plays an important role in the tidal dynamics change in Bohai Bay. 3) It is considered that the sea level return periods will decrease owing to the influence of sea level rise and land subsidence, therefore design tide level will change in relation展开更多
The mean sea level, extreme sea level, and astronomical tide in Hangzhou Bay were analyzed using the tide gage data from 1978 to 2017 in Tanxu station, and the effects of rising sea levels on floods were estimated. Th...The mean sea level, extreme sea level, and astronomical tide in Hangzhou Bay were analyzed using the tide gage data from 1978 to 2017 in Tanxu station, and the effects of rising sea levels on floods were estimated. The mean sea level in Hangzhou Bay showed a significant rising trend of 4.6mm per year in 1978-2017. This rate was much higher than the mean sea level of the China seas, and the extreme sea level in Hangzhou Bay increased at the rate of 0.011 m per year. During 1978-2017, the mean tide range increased at the rate of 1.30 cm per year. The amplitude of M2 significantly increased at the rate of 0.57cm per year, whereas the phase lag decreased at the rate of --0.21° per year. The amplitude and phase lag of the K1 tidal component slightly decreased at the rate of --0.03 cm per year and -0.07° per year, respectively. The changes in extreme sea level in Hangzhou Bay were mainly caused by variations in mean sea level. The coastal areas of Hangzhou Bay at risk from flooding due to the 100-year sea level return will increase by about 400 km^2 by 2050.展开更多
In the paper,the authors collect,discuss,and find out several connections,equivalences,closed-form formulas,and combinatorial identities concerning partial Bell polynomials,falling factorials,rising factorials,extende...In the paper,the authors collect,discuss,and find out several connections,equivalences,closed-form formulas,and combinatorial identities concerning partial Bell polynomials,falling factorials,rising factorials,extended binomial coefficients,and the Stirling numbers of the first and second kinds.These results are new,interesting,important,useful,and applicable in combinatorial number theory.展开更多
Although future sea level rise along the China coast has been projected by various studies for different representative concentration pathways(RCPs),the projections for different warming thresholds,e.g.1.5℃ and 2.0℃...Although future sea level rise along the China coast has been projected by various studies for different representative concentration pathways(RCPs),the projections for different warming thresholds,e.g.1.5℃ and 2.0℃,have not been done specifically for this region,to the best of our knowledge.We provide such a projection here based on the climate projections of Coupled Model Intercomparison Project Phase 5(CMIP5).The projections are given for 20 tide-gauge stations along the coast of China,Korea,Japan,and Vietnam.Vertical land motion(VLM)is also estimated for stations that have tide gauge records and satellite altimetry both covering the period of 1993-2018.Local land motion(LLM)is then estimated by subtracting the land motion due to glacial isostatic adjustment(GIA)from VLM.Without considering LLM,sea level rise by 2100 at median probability is projected to be 38-49 cm relative to the average sea level over 1986-2005 under warming of 1.5℃,and increase to 46-57 cm when the warming threshold is increased to 2.0℃.The steric component is the main contributor to this increase in sea level.Inclusion of LLM will not affect the sea level increase between the two warming thresholds,but it will make the local sea level rise by 2100 at certain locations substantially higher(up to 36 cm)or lower(up to 13 cm).展开更多
Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and geodesy.While only a small part of tidal range,these components can be ...Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and geodesy.While only a small part of tidal range,these components can be larger at certain coastal locations due to shelf resonances and other effects.Here,we discuss observations of the M3lunar terdiurnal tide using 9-year windowed tidal harmonic analyses at 157 tide gauges compares to a global assimilation model(TPXO9v5a),with a focus on the Western Pacific and the European Shelf.TPXO9v5a does well in estimating the observed M_(3)amplitudes and phase lags in most regions,though determinations in coastal zones and in morphologically complex areas are coarse and often inaccurate.We also employ a shallow-water model(MARS)on the European Shelf,which can yield localized improvement over TPXO.In five subregions of the European Shelf,regional root-mean-squared-errors(RMSEs)are lower(and thus a better fit)at three locations for TPXO for amplitudes,and three for phase lags,with MARS simulations being a better fit in the other subregions.We also show that some locations have experienced significant long-term increases and/or decreases in the M_(3)amplitude over time,likely related to resonance changes under sea level rise(SLR)which can modulate the oceanic response to astronomical forcing.This hypothesis is explored for Europe using the MARS model by applying various sea level rise scenarios,showing that the directionality(positive or negative)of the long-term changes in M_(3)amplitudes over time match the model results for more than half of our validation stations.展开更多
The life cycle pattern of empires is pervasive worldwide,and this is caused by multiple factors.In the history of Vietnam,there are totally about ten empires or dynasties,which have aggregately lasted for more than on...The life cycle pattern of empires is pervasive worldwide,and this is caused by multiple factors.In the history of Vietnam,there are totally about ten empires or dynasties,which have aggregately lasted for more than one thousand years.Here,we apply the life cycle model and agent-based modeling to uncover the underlying mechanisms of the life cycle pattern for Vietnam empires.Macroscopically,the man-land relationship greatly shapes the life cycle pattern of traditional agricultural empires.The balancing process between land and population is critical for the empires.The relationship between incomes and costs has determined the actions or strategies of the social members or individuals.It suggests that our optimal solutions and simulations have perfectly matched the real history of Vietnam.Under three optimal solutions,the distributions of simulated and real empire durations in history can be well-matched,in terms of both discrete(histogram)and continuous forms(kernel density).It indicates that the history of human society is a dynamic process,which is determined by certain evolutionary rules and regulations.Therefore,we are able to back-calculate,simulate,and even predict the future of empires or countries.展开更多
For the discovery and analysis of Jebel Waqf as Suwwan (JWS) Impact Crater, Jordan pushed the authors to consequently focusing on other unusual geologic phenomena such as circular/oval structures (some of “crypto-vol...For the discovery and analysis of Jebel Waqf as Suwwan (JWS) Impact Crater, Jordan pushed the authors to consequently focusing on other unusual geologic phenomena such as circular/oval structures (some of “crypto-volcanic” origin), disharmonic folding, horizontal stylolites, and a broad stripe of?Sanidine-Hornfels-Facies, all of them hosted in Upper Cretaceous/Paleogene carbonate rocks exposed across Jordan and adjacent areas. Shatter cones are the most useful tools during field work in the realm of circular structures. In addition to the impact-geologic data of JWS Impact Structure hitherto available, the cooling process of melted Lower Cretaceous Kurnub-Sandstone could be verified by microscopically identified SiO2-modifications between the melting point (1714°C) and low temperatures. In comparison with the Suffield 500 tons explosion tests [20] and with the Ries Impact Crater, Germany, excavation and vaporization processes of target rocks demand drilling between Central Uplift and Inner Ring of the JWS Impact Structure (“Chert-Carbonate-Impact-Chess Game”). In a scenario: “Impacting meets Plate Tectonics”, phenomena like disharmonic folding, horizontal stylolites, and an abundance of circular/oval structures of high diameter variation through northwest Jordan are discussed under aspects of gravitational gliding, effects of seismic surface waves (Love-), transpressional structures related to Jordan Rift-Tectonics, and possible impact processes of unknown number occurred on the Arabian Plate in southeastern direction with northwest-directed impulse. The so-called “Mottled Zone” of Jordan and Palestine owning a high number (~100) of mineral neoformations with formation temperatures up to ~1120°C(pseudo-wollastonite = β-CaSiO3), is to be interpreted as of “Sanidine-Hornfels-Impact Facies” under ricochet conditions along an “Avenue of Ricochet-Impact-Thermo-Cataclysm”. Marble-related travertines represent a low temperature facies of the impact event. The temporal projection of patterns like Rapid Climate Change (RCC), astrophysical data [Hoyle’s Comet: 47], acid events in ice-cores, tektite fall, Rise and Fall of Neolithic/Bronze Age Cultures, reveals an amazing “Ensemble” of coincidences among all of these parameters since the Middle/Upper Pleistocene boundary throughout Holocene. Ten short Interval Cases are discussed as being “Rare Event”- suspicious. Myths like the “Gilgamesch Epos” and “John’s Apocalypse” surprisingly provide realistic hints on impact events comparable with modern observations and experiments, which are: approach of extraterrestrial bodies, impact cratering, earthquakes and faulting, supercyclonic whirl-storms (wildfires), effects of hot ejecta, destruction of fauna, flora, and cities, long-lasting flooding, darkness caused by ashes and dust circulating in atmosphere and stratosphere (sintwinter), and environmental pollution. Such hints were handed down in myths of ~180 ethnic peoples around the globe. “High probability Cases” focus on impact events on ~9600 yr B.P and on ~6000 yr B.P. Other “Rare Events” may have possibly occurred about ~8000 yr B.P. and on ~3200 yr. B.P. (all radiocarbon yr.cal.). Core-drilling in the pull-apart basins of the Jordan Rift System (Dead Sea, Lake Tiberias) as traps having possibly preserved volcanic and impact ejecta would be a challenging international and interdisciplinary project.展开更多
This paper mainly aims at proposing an effective method of speed control of the low power motors like Permanent Magnet Direct Current (PMDC) motor used in the orthopedic surgeries using a natural optimization techniqu...This paper mainly aims at proposing an effective method of speed control of the low power motors like Permanent Magnet Direct Current (PMDC) motor used in the orthopedic surgeries using a natural optimization technique called genetic algorithm. Using this method, better values of Performance parameters like rise time, settling time, fall time, peak overshoot and steady state are achieved compared to the conventional PI controller. The SIMUINK MODEL of both the controller operation is obtained using MATLAB version R2013a. The simulated results reveal that the proposed control drive exhibits reduced peak overshoot, rise time, settling time and steady state error. An experimental setup is devised to validate the simulation results. The comparative analysis made depicts the superiority of the proposed algorithm with reference to its conventional counterpart.展开更多
文摘From the Industrial Revolution to the World War,the past three centuries have witnessed the development and rise and fall of Great Britain.Great Britain,an island country with a total area of about 240,000 square kilometers,enjoys a very important place in the world in modern history.Great Britain was the first industrial country and created the epoch-making laissez-faire capitalism and built a sun-never-set empire.It was also the leadership of the world from the middle of 18^th and to the middle of 19^th century.In retrospect to the rise of Great Britain,we can easily see that it was by relying on an innovative culture that the island country became a great power in Europe and then became the dominant empire in the world.This innovative character permeates in all kinds of culture including industrial,military,technological,politic and diplomatic.As for the main cause of Great Britain’s rise,this thesis attempts to analyze from three aspects,that is,the emancipation of mind,the advancement of military power,and the development of technology.After the World War,Great Britain began to suffer a decline in status and was reduced to a second class developed country.That is also because the conservative factor in its culture which blocks its development and the potential to innovate new things.The past years has witnessed the fall of the empire and also left us much inspiration.Take the history as a mirror,the thesis will focus on the“English disease”and influence of the World War to make an analysis on Great Britain’s fall.A conclusion of inspiration would also be included.
文摘The novel The Rise and Fall of Wing Shing Street delves into the reality of Hong Kong residents deeply attuned to spatial awareness but detached from temporal significance,entangling emotions surrounding time and space.Through narrative interruption and extension,the author portrays the genuine struggles of Hong Kong inhabitants-juxtaposing the blurred boundaries of time and space and the inherent rootlessness of reality within a fictionalized framework.Emphasizing the 20th-century human condition,wherein spatial awareness overshadows temporal understanding,the novel underscores the consequences:a loss of history and cultural identity.With a fresh perspective,the narrative explores the interplay of time and space,accentuating both the fictitious and authentic dimensions.This prompts readers to reconsider their history,culture,and the current moment,ultimately highlighting the pivotal role of temporal awareness.
文摘This paper examines various aspects of the design process and subsequent field test measurements of a large and complex substation grounding system. The study and measurements show that soil layering and lead interference can have a significant impact on the appropriate test location that yields the exact substation ground impedance. Applying a specific percentage rule such as the 61.8% rule for uniform soils to obtain the true ground impedance may lead to unacceptable errors for large grounding systems. This poses significant problems when attempting to validate a design based on raw test data that are interpreted using approximate methods to evaluate substation ground impedance, and determine ground potential rise (GPR), touch and step voltages. Advanced measurement methodologies and modern software packages were used to obtain and effectively analyze fall of potential test data, compute fault current distribution, and evaluate touch and step voltages for this large substation. Fault current distribution between the grounding system and other metallic paths were computed to determine the portion of fault current discharged in the grounding system. The performance of the grounding system, including its GPR and touch and step voltages, has been accurately computed and measured, taking into account the impedance of the steel material used of the ground conductors and circulating currents within the substation grounding system.
文摘The controlling and influencing effects of the joint action of plates surrounding China on strong earthquakes in Chinese mainland are discussed, and the characteristics of seismic activities in the West of China and neighboring regions are further studied. The results show that the seismic activity in the West of China and neighboring regions not only has the characteristics of high tide and low tide alternation but also has the characteristics of rising in one region while falling in another, and the rise and fall of seismicity are in some proportion. The above characteristics are useful for the prediction of main body region of strong earthquakes in Chinese mainland, especially for the judgement of the ending time of the high tide period.
文摘The idea of this study is derived from observing the profitability of stock investments following the phenomena of continuously rising(or falling)prices of stocks and continuously overbought(or oversold)signals emitted by technical indicators.We employ the standard event study approach and technical trading strategies to explore whether investors would exploit profits in trading the constituent stocks of the Korea Composite Stock Price Index 50 and Shanghai Stock Exchange 50 when the aforementioned continuous phenomena occur.We find that both the Korean and Chinese stock markets are not fully efficient;this finding may enhance the robustness of the existing literature.In addition,we reveal that contrarian strategies are appropriate for the trading stocks listed on the Korean stock market for all the cases investigated in this study.However,momentum strategies are appropriate for the Chinese stock market when continuously rising stock prices and overbought signals are simultaneously observed.These findings imply that the difference in investor behaviors between the Korean and Chinese stock markets might result in dissimilar trading strategies being employed for these two markets.
文摘A nonlinear two-dimension dynamic model of storm surge (SS) and astronomical tide(AT) was used to investigate the effects of SS and AT on expected sea level rise (SLR) at principalcoastal stations in the Shanghai region and to estimate numerically the probable maximum water lerel for2010 - 2050. Evidence suggests tha SLR causes reduction of SS; that its influence on SS depends on theintensity and path of a tropical cyclone and the station locality; tha the SLR’s effects on AT vary periodi-cally, with the peried being the same as tha of the AT’s: and that as the SLR increment grows, its impactincreases; below mean sea level (MSL) the effect is positive at rising tide and negative at ebb tide, andvice versa for the effect above MSL. Study of the probable maximum water level (by assuming SLR, SSalong favorable tropical cyclone’s path, its possible maximum intensity and effectivee spring AT at a rangeof set paths of Cyclones 5612, 8114, 9417) showed that the probable maximum water level is 740, 745,and 751 cm in the years 2010, 2030, and 2050, respetively, over the target region.
文摘During the Tang Dynasty,the land of Shu was composed of the Ba and Shu areas,which were adjacent to present-day Hanzhong city of Shaanxi province to the north,northern Yunnan province to the south,Wushan county of Chongqing to the east,and Xichang city of Sichuan province to the west.In the nearly 300 years of rule under the dynasty,a number of poets,whether they were born or just worked and lived there for a short period of time,wrote many immortal poems,which constitute an integral part of Tang poetry.They range from Chen Zi’ang and Wang Bo of the early Tang to Li Shangyin,Wen Tingyun,and Wei Zhuang of the late Tang.The land of Shu is,therefore,the witness of the rise and fall of Tang poetry.
文摘Tide gauge data from 1950 to 2015 are used to analyze sea level change, tidal change, return levels, and design tide levels under rising sea level scenarios in Bohai Bay. Results show the following: 1) Since 1950 sea levels in Bohai Bay show a significant rising trend of 3.3 mm per year. The speed has been particularly rapid in 1980e2015 at a rate of 4.7 mm per year. 2) Astronomical tides showed a clear long-term trend in 1950e2015. The amplitude and phase lag of the M2 tide constituent decreased at a rate of 0.21 cm per year and 0.11 per year, respectively and the phase lag of K1 decreased at a rate of 0.09 per year, whereas there was little change in its amplitude. The mean high and low tides increased at a rate of 0.08 and 0.52 cm per year, respectively, whereas the mean tidal range decreased at a rate of 0.44 cm per year. Results from numerical experiments show that local sea level rise plays an important role in the tidal dynamics change in Bohai Bay. 3) It is considered that the sea level return periods will decrease owing to the influence of sea level rise and land subsidence, therefore design tide level will change in relation
基金National Key Research and Development Program of China (2016YFC1401900, 2017YFC1404200)National Natural Science Foundation of China (41706020, 41406032, 41706019)Open Fund of the Key Laboratory of Research on Marine Hazards Forecasting.
文摘The mean sea level, extreme sea level, and astronomical tide in Hangzhou Bay were analyzed using the tide gage data from 1978 to 2017 in Tanxu station, and the effects of rising sea levels on floods were estimated. The mean sea level in Hangzhou Bay showed a significant rising trend of 4.6mm per year in 1978-2017. This rate was much higher than the mean sea level of the China seas, and the extreme sea level in Hangzhou Bay increased at the rate of 0.011 m per year. During 1978-2017, the mean tide range increased at the rate of 1.30 cm per year. The amplitude of M2 significantly increased at the rate of 0.57cm per year, whereas the phase lag decreased at the rate of --0.21° per year. The amplitude and phase lag of the K1 tidal component slightly decreased at the rate of --0.03 cm per year and -0.07° per year, respectively. The changes in extreme sea level in Hangzhou Bay were mainly caused by variations in mean sea level. The coastal areas of Hangzhou Bay at risk from flooding due to the 100-year sea level return will increase by about 400 km^2 by 2050.
基金supported in part by the National Natural Science Foundation of China(Grant No.12061033)by the Research Program of Science and Technology at Universities of Inner Mongolia Autonomous Region(Grants No.NJZY20119)by the Natural Science Foundation of Inner Mongolia(Grant No.2019MS01007),China.
文摘In the paper,the authors collect,discuss,and find out several connections,equivalences,closed-form formulas,and combinatorial identities concerning partial Bell polynomials,falling factorials,rising factorials,extended binomial coefficients,and the Stirling numbers of the first and second kinds.These results are new,interesting,important,useful,and applicable in combinatorial number theory.
文摘Although future sea level rise along the China coast has been projected by various studies for different representative concentration pathways(RCPs),the projections for different warming thresholds,e.g.1.5℃ and 2.0℃,have not been done specifically for this region,to the best of our knowledge.We provide such a projection here based on the climate projections of Coupled Model Intercomparison Project Phase 5(CMIP5).The projections are given for 20 tide-gauge stations along the coast of China,Korea,Japan,and Vietnam.Vertical land motion(VLM)is also estimated for stations that have tide gauge records and satellite altimetry both covering the period of 1993-2018.Local land motion(LLM)is then estimated by subtracting the land motion due to glacial isostatic adjustment(GIA)from VLM.Without considering LLM,sea level rise by 2100 at median probability is projected to be 38-49 cm relative to the average sea level over 1986-2005 under warming of 1.5℃,and increase to 46-57 cm when the warming threshold is increased to 2.0℃.The steric component is the main contributor to this increase in sea level.Inclusion of LLM will not affect the sea level increase between the two warming thresholds,but it will make the local sea level rise by 2100 at certain locations substantially higher(up to 36 cm)or lower(up to 13 cm).
基金funded by the National Key Research and Development Program(Grant No.2021YFB3900400)。
文摘Improved determinations of the oft-ignored third-degree ocean tides can yield better accuracy for tidal predictions,numerical model solutions,and geodesy.While only a small part of tidal range,these components can be larger at certain coastal locations due to shelf resonances and other effects.Here,we discuss observations of the M3lunar terdiurnal tide using 9-year windowed tidal harmonic analyses at 157 tide gauges compares to a global assimilation model(TPXO9v5a),with a focus on the Western Pacific and the European Shelf.TPXO9v5a does well in estimating the observed M_(3)amplitudes and phase lags in most regions,though determinations in coastal zones and in morphologically complex areas are coarse and often inaccurate.We also employ a shallow-water model(MARS)on the European Shelf,which can yield localized improvement over TPXO.In five subregions of the European Shelf,regional root-mean-squared-errors(RMSEs)are lower(and thus a better fit)at three locations for TPXO for amplitudes,and three for phase lags,with MARS simulations being a better fit in the other subregions.We also show that some locations have experienced significant long-term increases and/or decreases in the M_(3)amplitude over time,likely related to resonance changes under sea level rise(SLR)which can modulate the oceanic response to astronomical forcing.This hypothesis is explored for Europe using the MARS model by applying various sea level rise scenarios,showing that the directionality(positive or negative)of the long-term changes in M_(3)amplitudes over time match the model results for more than half of our validation stations.
基金supported by the National Social Science Foundation of China(18VXK005,19ZDA143&17ZDA117)National Science Foundation of China(72203005)+1 种基金Shaanxi Province Education Department Project(20JT007)supported by High-performance Computing Platform of Peking University and School of Economics,Peking University.
文摘The life cycle pattern of empires is pervasive worldwide,and this is caused by multiple factors.In the history of Vietnam,there are totally about ten empires or dynasties,which have aggregately lasted for more than one thousand years.Here,we apply the life cycle model and agent-based modeling to uncover the underlying mechanisms of the life cycle pattern for Vietnam empires.Macroscopically,the man-land relationship greatly shapes the life cycle pattern of traditional agricultural empires.The balancing process between land and population is critical for the empires.The relationship between incomes and costs has determined the actions or strategies of the social members or individuals.It suggests that our optimal solutions and simulations have perfectly matched the real history of Vietnam.Under three optimal solutions,the distributions of simulated and real empire durations in history can be well-matched,in terms of both discrete(histogram)and continuous forms(kernel density).It indicates that the history of human society is a dynamic process,which is determined by certain evolutionary rules and regulations.Therefore,we are able to back-calculate,simulate,and even predict the future of empires or countries.
文摘For the discovery and analysis of Jebel Waqf as Suwwan (JWS) Impact Crater, Jordan pushed the authors to consequently focusing on other unusual geologic phenomena such as circular/oval structures (some of “crypto-volcanic” origin), disharmonic folding, horizontal stylolites, and a broad stripe of?Sanidine-Hornfels-Facies, all of them hosted in Upper Cretaceous/Paleogene carbonate rocks exposed across Jordan and adjacent areas. Shatter cones are the most useful tools during field work in the realm of circular structures. In addition to the impact-geologic data of JWS Impact Structure hitherto available, the cooling process of melted Lower Cretaceous Kurnub-Sandstone could be verified by microscopically identified SiO2-modifications between the melting point (1714°C) and low temperatures. In comparison with the Suffield 500 tons explosion tests [20] and with the Ries Impact Crater, Germany, excavation and vaporization processes of target rocks demand drilling between Central Uplift and Inner Ring of the JWS Impact Structure (“Chert-Carbonate-Impact-Chess Game”). In a scenario: “Impacting meets Plate Tectonics”, phenomena like disharmonic folding, horizontal stylolites, and an abundance of circular/oval structures of high diameter variation through northwest Jordan are discussed under aspects of gravitational gliding, effects of seismic surface waves (Love-), transpressional structures related to Jordan Rift-Tectonics, and possible impact processes of unknown number occurred on the Arabian Plate in southeastern direction with northwest-directed impulse. The so-called “Mottled Zone” of Jordan and Palestine owning a high number (~100) of mineral neoformations with formation temperatures up to ~1120°C(pseudo-wollastonite = β-CaSiO3), is to be interpreted as of “Sanidine-Hornfels-Impact Facies” under ricochet conditions along an “Avenue of Ricochet-Impact-Thermo-Cataclysm”. Marble-related travertines represent a low temperature facies of the impact event. The temporal projection of patterns like Rapid Climate Change (RCC), astrophysical data [Hoyle’s Comet: 47], acid events in ice-cores, tektite fall, Rise and Fall of Neolithic/Bronze Age Cultures, reveals an amazing “Ensemble” of coincidences among all of these parameters since the Middle/Upper Pleistocene boundary throughout Holocene. Ten short Interval Cases are discussed as being “Rare Event”- suspicious. Myths like the “Gilgamesch Epos” and “John’s Apocalypse” surprisingly provide realistic hints on impact events comparable with modern observations and experiments, which are: approach of extraterrestrial bodies, impact cratering, earthquakes and faulting, supercyclonic whirl-storms (wildfires), effects of hot ejecta, destruction of fauna, flora, and cities, long-lasting flooding, darkness caused by ashes and dust circulating in atmosphere and stratosphere (sintwinter), and environmental pollution. Such hints were handed down in myths of ~180 ethnic peoples around the globe. “High probability Cases” focus on impact events on ~9600 yr B.P and on ~6000 yr B.P. Other “Rare Events” may have possibly occurred about ~8000 yr B.P. and on ~3200 yr. B.P. (all radiocarbon yr.cal.). Core-drilling in the pull-apart basins of the Jordan Rift System (Dead Sea, Lake Tiberias) as traps having possibly preserved volcanic and impact ejecta would be a challenging international and interdisciplinary project.
文摘This paper mainly aims at proposing an effective method of speed control of the low power motors like Permanent Magnet Direct Current (PMDC) motor used in the orthopedic surgeries using a natural optimization technique called genetic algorithm. Using this method, better values of Performance parameters like rise time, settling time, fall time, peak overshoot and steady state are achieved compared to the conventional PI controller. The SIMUINK MODEL of both the controller operation is obtained using MATLAB version R2013a. The simulated results reveal that the proposed control drive exhibits reduced peak overshoot, rise time, settling time and steady state error. An experimental setup is devised to validate the simulation results. The comparative analysis made depicts the superiority of the proposed algorithm with reference to its conventional counterpart.