In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mit...In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.展开更多
Critical for metering and protection in electric railway traction power supply systems(TPSSs),the measurement performance of voltage transformers(VTs)must be timely and reliably monitored.This paper outlines a three-s...Critical for metering and protection in electric railway traction power supply systems(TPSSs),the measurement performance of voltage transformers(VTs)must be timely and reliably monitored.This paper outlines a three-step,RMS data only method for evaluating VTs in TPSSs.First,a kernel principal component analysis approach is used to diagnose the VT exhibiting significant measurement deviations over time,mitigating the influence of stochastic fluctuations in traction loads.Second,a back propagation neural network is employed to continuously estimate the measurement deviations of the targeted VT.Third,a trend analysis method is developed to assess the evolution of the measurement performance of VTs.Case studies conducted on field data from an operational TPSS demonstrate the effectiveness of the proposed method in detecting VTs with measurement deviations exceeding 1%relative to their original accuracy levels.Additionally,the method accurately tracks deviation trends,enabling the identification of potential early-stage faults in VTs and helping prevent significant economic losses in TPSS operations.展开更多
In the summer of 2024, following a strong El Ni?o event in the preceding winter, the tropical Indian Ocean and tropical North Atlantic recorded their highest SSTs since 1961, along with a significant westward shift an...In the summer of 2024, following a strong El Ni?o event in the preceding winter, the tropical Indian Ocean and tropical North Atlantic recorded their highest SSTs since 1961, along with a significant westward shift and intensification of the western Pacific subtropical high(WPSH). Under these conditions, China experienced its hottest summer since 1961,and was hit by a series of high-impact extreme weather and climate events. From 9 June to 2 July, southern China experienced an unprecedented extreme precipitation event that exceeded the well-known 1998 summer precipitation event in both duration and impact scope, resulting in devastating floods in the Yangtze River basin. Subsequently, in early to midJuly, the Huanghe-Huaihe Basin suffered from a severe drought–flood abrupt alternation event, heavily affecting Henan and Shandong. Meanwhile, southern China underwent a widespread heatwave event lasting 74 days, ranking as the second most intense since 1961. From late July to the end of August, northern China faced unusually frequent heavy precipitation events, with cumulative precipitation reaching the second highest for the same period since 1961, causing floods in many rivers of northern China. This study provides a timely summary and assessment of the characteristics and impacts of these extreme events. It serves as a reference for climate change research, including mechanism analysis, numerical simulation,and climate event attribution, and also offers valuable insights for improving meteorological disaster prevention and mitigation strategies.展开更多
Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in...Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in June followed by floods in July.The 2024 event was the most severe since 1981.This study demonstrates that such compound extreme events are closely linked to anomalous subseasonal evolution of large-scale atmospheric circulation.During the drought phase,the East Asian subtropical westerly jet(EAJ)shifts southward,and the western Pacific subtropical high(WPSH)exhibits anomalous strengthening with its western ridge line displaced southward.The flood phase is characterized by acceleration of the EAJ,westward extension of the WPSH,and enhanced southwestern moisture transport from the western Pacific.Beyond these typical features,the 2024 early summer circulation exhibited unique characteristics:Anomalous northeastward intensification of the WPSH facilitated merged moisture influx from both the Indian Ocean and the western Pacific along the southeast pathway into the HHHRB in July,resulting in the highest net moisture inflow at the southern boundary of the HHHRB since 1981.The synergistic effects of multiple factors primarily explain the exceptionally intense DFAA event in 2024.展开更多
It is an objective fact that the weather is unpredictable.Even the famous meteorologist,Academician Chu Ko Chen,has only a partial understanding of the changing laws of wind and rain.Even though ancient people summari...It is an objective fact that the weather is unpredictable.Even the famous meteorologist,Academician Chu Ko Chen,has only a partial understanding of the changing laws of wind and rain.Even though ancient people summarized the 24 solar terms by observing the annual activities of the sun for a long time,because they ignored the impact of the activities of the moon on the Earth’s climate change on a small scale,the 24 solar terms they summarized often could not accurately predict the change of the Earth’s climate.Therefore,the author studied the influence of lunar activities on the Earth’s climate change,finds out the law of the influence of lunar activities on the Earth’s climate change on a small scale,and summarizes the eternal climate change pattern determined by the activities of the sun and the moon.In addition,the author also reveals the causes and countermeasures of global warming and the frequent occurrence of extreme weather as well as environmental change.展开更多
Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variab...Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variables are the main contributors to this cyclical adjustment of the Earth’s climate. Such changes may be induced purposefully, because of burning fossil fuels, clearing forests, and raising animals, or they may be natural, brought on by significant volcanic eruptions or variations in the sun’s activity. By significantly increasing the amount of greenhouse gases already in the atmosphere, this heightens the greenhouse effect and contributes to global warming. This work includes several additional theoretical and practical explanations of sustainable development. The theoretical work encompasses hundreds of researches that identify requirements for how development routes might satisfy sustainable development (SD) criteria using economic theory, complex systems approach, ecological science, and other techniques. The agreements made by the Parties in various nations across the world will consider a wide range of perspectives about what would be considered undesirable effects on the environment, the climate system, sustainability, economic growth, or food production.展开更多
The effect of pruning severity on tree growth was analyzed by change point detection using segmented regression. The present study applied this analysis to a well-known published data set including diameter growth res...The effect of pruning severity on tree growth was analyzed by change point detection using segmented regression. The present study applied this analysis to a well-known published data set including diameter growth response, tree age, pruning severity and pretreatment crown size. First, multiple regression analysis was performed to assess the effect of tree age, pruning severity and pretreatment crown size on diameter growth response. Next, segmented regression analysis was performed to assess the effect of pruning severity on diameter growth response. The results of the multiple regression showed that diameter growth response was significantly influenced by pruning severity and pretreatment crown size. The results of the segmented regression showed that in the whole data set, an abrupt change toward a decrease in diameter growth response was detected at 25% of the live crown removed. However, in the group of fully crowned and open-grown, diameter growth response continuously decreased with increasing pruning severity with no significant abrupt change, whereas in the group of 70% - 90% live crown, diameter growth response did not significantly decrease up to the break point (53% crown removed) and then abruptly decreased. This may be the first study to show the numerical evaluation of the effect of pruning severity on tree growth by change point analysis.展开更多
Based on the monthly precipitation data from 43 stations in North China from 1979 to 2008,the variation characteristics of precipitation in North China in recent 30 years were analyzed by means of empirical orthogonal...Based on the monthly precipitation data from 43 stations in North China from 1979 to 2008,the variation characteristics of precipitation in North China in recent 30 years were analyzed by means of empirical orthogonal function(EOF)decomposition,Morlet wavelet transform and Mann-Kendall test.The results showed that the spatial distribution of annual and seasonal precipitation was basically identical in North China,while the annual and summer precipitation from the middle of 1980s to the middle of 1990s were obviously more than these in other periods,and there was great annual variation in spring precipitation in 1990s,while autumn precipitation was higher from 1980s to 1990s and then went down after the beginning of 21st century,which was opposite to winter precipitation,namely there was more winter precipitation from 1980s to 1990s and fewer winter precipitation after the beginning of 21st century.In addition,the annual and summer precipitation changed abruptly in 1997,and there was no obvious change in spring precipitation and autumn precipitation,while winter precipitation had an abrupt change in 2000.Meanwhile,wavelet analysis revealed that the variation period of annual and seasonal precipitation was 3-4 years.展开更多
[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 195...[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 1951 to 2009,the annual,seasonal,and monthly variation of sunshine duration in recent 60 years were analyzed,as well as its relationship with meteorological factors,and sunshine duration was detected by means of climate mutation theory.[Result] Annual sunshine duration in Dalian in recent 60 years showed decrease trend on the whole,and its climatic variation rate was-3.31 h/a,with larger annual variation,namely the difference between maximum value(1978) and minimum value(2003) reached 681 h;there was obvious seasonal variation in sunshine duration,with the order of autumn>summer>winter>spring,and their climatic variation rate were-1.18,-1.15,-0.91 and-0.62 h/a;except for March,sunshine duration in each month went down,especially October,while there was slight increase in March;sunshine percentage had inverse correlation relationship with total cloudiness,relative humidity and heavy fog days;annual sunshine duration reduced abruptly around 1983.[Conclusion] Our study could provide scientific foundation for the development of agriculture and forestry in Dalian City.展开更多
[Objective] The aim is to expound the abrupt rainstorm in the central Hunan Province on May 6 in 2010.[Method] By dint of NCEP 1°×1° reanalysis data,routine observation data,auto-station precipitation a...[Objective] The aim is to expound the abrupt rainstorm in the central Hunan Province on May 6 in 2010.[Method] By dint of NCEP 1°×1° reanalysis data,routine observation data,auto-station precipitation and FY-2C satellite data,the large-scale circulation background and physical condition during the large rainstorm period from the night on May 5 to 6 in 2010 were analyzed.The large scale environment,meso-scale characteristics and potential causes for the formation of large precipitation were revealed.By dint of FY-2D satellite and water-vapor cloud image,infrared cloud image,4 black light temperature,the variation characteristics of heavy rainstorm convection system were analyzed.[Result] Under the favorable environment background,the rainstorm was induced by the meso-scale convection system,and it had close relation with the upper-air trough,shear line in the middle and low layer,ground weak and cold air and the torrent in the upper and low latitude.The result of all kinds of physical quantities suggested that the meso-scale rainstorm above the air had distinct characteristics and the heavy precipitation was in the middle Hunan Province.It was caused by meso-system.The dynamic dry belt above the satellite,TBB=-60℃ center and the large value area of the gradient could provide references for the forecast and pre-warning of large rainstorm.[Conclusion] The study accumulated experiences for the forecast and report of rainstorm in Hunan Province.展开更多
A great amount of results obtained from the experiments carried out by a number of scientists and by us especially have been subjected to modeling which enabled to implement analysis according to the method of dialect...A great amount of results obtained from the experiments carried out by a number of scientists and by us especially have been subjected to modeling which enabled to implement analysis according to the method of dialectics ＂cause^-~consequence＂. A variety of numerous factors （chemical, physical, etc.） that engender the same biological process have been characterized by a single vector-energy （E） which along with the time （T） parameter defines the dose： D （dose） = E （energy） x T （time）. Dose （D） as a cause and biological process as a consequence revealed a number of interrelated regularities such as discontinuity, continuity, homogeneity, heterogeneity, relativity, successiveness, abruptness, spontaneity and correlation between biological processes. Thus, the life cycle in vivo was based on these regularities. Besides, these regularities are necessary and sufficient to prove biologically the bioprocess realized by the mechanism of ＂quantum theory＂.展开更多
[Objective] The aim was to study the characteristics of temperature changes in Liupanshui in recent 50 years. [Method] Based on the monthly temperature data from 3 observational stations in Liupanshui from 1960 to 200...[Objective] The aim was to study the characteristics of temperature changes in Liupanshui in recent 50 years. [Method] Based on the monthly temperature data from 3 observational stations in Liupanshui from 1960 to 2009 and by employing the linear method and Mann-Kendall method, features and abrupt changes of temperature in Liupanshui were discussed. [Result] The results indicated the temperature in Liu Panshui increased obviously in recent 50 years at a rate of 0.096 ℃/10 a. Average temperature in spring was decreasing, but was increasing in summer, autumn and winter at different rate. The average temperature changed the most in winter, followed by summer and autumn and changed the least in spring. The temperature changes were not distinct before the early 1980s. Temperature increased significantly after 80s, having distinct waving nature and several mutation points. The distinct mutation point appeared in 1978 and the annual average temperature increased significantly after 1978. There was no obvious mutation of temperature in spring; the mutation points of temperature in summer, autumn and winter were 1978, 1982 and 1985. [Conclusion] The study provided reference for the short term forecast of climate in Liupanshui City.展开更多
By means of linear function and Mann-Kendall test method,the climate change characteristics of temperature and precipitation from Zhumadian meteorological station in recent 50 years were analyzed.The results revealed ...By means of linear function and Mann-Kendall test method,the climate change characteristics of temperature and precipitation from Zhumadian meteorological station in recent 50 years were analyzed.The results revealed that annual mean temperature and extreme temperature showed increase trend,especially minimum temperature,and there was a slight increase in annual precipitation.Temperature increase was more obvious in spring than that in autumn and winter,while there was a decrease of temperature in summer.Meanwhile,precipitation went down in spring and autumn,particular in autumn,while the increase of summer precipitation was most obvious.Mann-Kendall test showed that temperature in Zhumadian had obvious increase trend in recent 50 years,while there was abrupt change in temperature in the late 1990s and fluctuation change in annual precipitation.展开更多
[Objective] The aim was to analyse the variation characteristics of temperature in Anqing City and urban heat island effect.[Method] Based on the observation data of temperature from Anqing Station,other surrounding m...[Objective] The aim was to analyse the variation characteristics of temperature in Anqing City and urban heat island effect.[Method] Based on the observation data of temperature from Anqing Station,other surrounding meteorological stations and local automatic meteorological stations in suburbs,the annual variation of temperature and regional consistency was analysed,then the abrupt change of annual average temperature was tested by Mann-Kendall test,finally the influences of urban heat island effect on temperature variation in Anqing Station were studied.[Result] Affected by station migration and urban construction,the annual average temperature increased significantly in Anqing Station from 1977 to 2009,and the rising was more prominent after the middle of the 1990s.Mann-Kendall test showed that the change of temperature in Anqing Station was obviously abrupt around 1993;because of the development of urbanization,average temperature in Anqing Station was 0.8 ℃ higher than that in suburbs,and the minimum temperature rose more remarkably.In addition,urban heat island effect was the strongest in spring,followed by summer and autumn,while it was the weakest in winter.[Conclusion] The effects of urbanization development on the temperature in Anqing City were understood through this research.展开更多
Based on the meteorological data during 1959-2008 from five representative weather stations in the Urumqi River Basin and surrounding areas,the regional characteristics of temperature and precipitation in the basin fe...Based on the meteorological data during 1959-2008 from five representative weather stations in the Urumqi River Basin and surrounding areas,the regional characteristics of temperature and precipitation in the basin featuring multi-climatic zones were studied by means of some methods including wavelet analysis.As was shown in the results,the temperature in the whole Urumqi River Basin demonstrated a significant upward trend.The temperature increase particularly in autumn and winter made the greatest contribution to the marked ascent.The interdecadal temperature in the basin showed a tendency to decline before the period during 1970s-1980s while it was on the rise after 1990s on the whole.The most concentrated period of temperature mutations was in the late 1990s.At the same time,the precipitation also showed an escalating trend,which experienced a stage of unanimous upward trend after 1990s.The most concentrated period of precipitation mutations was in the early 1990s.展开更多
With an effective bianisotropy picture, high-frequency behaviours of different magnetic materials can be reconciled, and the higher permeability and higher resonance frequencies are achieved even in the GHz range. The...With an effective bianisotropy picture, high-frequency behaviours of different magnetic materials can be reconciled, and the higher permeability and higher resonance frequencies are achieved even in the GHz range. The validity of the bianisotropy picture is quantitatively verified by the in-plane anisotropic Fe34Co55Zr11 thin films. A prolate elliptical precession of the magnetization about its equilibrium direction is the key point, which can be induced by an artificial or an intrinsic bianisotropy system.展开更多
Under the impacts of climate change and human activities, great uncertainties still exist in the response of climate extremes, especially in Central Asia (CA). In this study, we investigated spatial-temporal variation...Under the impacts of climate change and human activities, great uncertainties still exist in the response of climate extremes, especially in Central Asia (CA). In this study, we investigated spatial-temporal variation trends and abrupt changes in 17 indices of climate extremes, based on daily climate observations from 55 meteorological stations in CA during 1957-2005. We also speculated as to which atmospheric circulation factors had the greatest impacts on climate extremes. Our results indicated that the annual mean temperature (Tav), mean maximum and minimum temperature significantly increased at a rate of 0.32ºC/10a, 0.24ºC/10a and 0.41ºC/10a, respectively, which was far higher than the increasing rates either globally or across the Northern Hemisphere. Other temperature extremes showed widespread significant warming trends, especially for those indices derived from daily minimum temperature. All temperature extremes exhibited spatially widespread rising trends. Compared to temperature changes, precipitation extremes showed higher spatial and temporal variabilities. The annual total precipitation significantly increased at a rate of 4.76 mm/10a, and all precipitation extremes showed rising trends except for annual maximum consecutive dry days (CDD), which significantly decreased at a rate of -3.17 days/10a. On the whole, precipitation extremes experienced slight wetter trends in the Tianshan Mountains, Kazakhskiy Melkosopochnik (Hill), the Kyzylkum Desert and most of Xinjiang. The results of Cumulative Deviation showed that Tav and Txav had a significant abrupt change around 1987, and all precipitation indices experienced abrupt changes in 1986. Spearman’s correlation analysis pointed to Siberian High and Tibetan Plateau Index_B as possibly being the most important atmospheric circulation factors affecting climate extremes in CA. A full quantitative understanding of these changes is crucial for the management and mitigation of natural hazards in this region.展开更多
Employing the compatibility method, we obtain the symmetries of the （3＋1）-dimensional Kadomtsev Petviashvili （KP） equation. Four types of similarity reductions of the KP equation are obtained by solving the corre...Employing the compatibility method, we obtain the symmetries of the （3＋1）-dimensional Kadomtsev Petviashvili （KP） equation. Four types of similarity reductions of the KP equation are obtained by solving the corresponding characteristic equations associated with symmetry equations. In addition, a lot of similarity solutions to the KP equation are obtadned.展开更多
Decadal/interdecadal climate variability is an important element in the CLIVAR (Climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation ...Decadal/interdecadal climate variability is an important element in the CLIVAR (Climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation have also been completed by Chinese scientists in recent years. In this paper, an introduction in outline for interdecadal climate variation research in China is presented. The content includes the features of interdecadal climate variability in China, global warming and interdecadal temperature variability, the NAO (the North Atlantic Oscillation)/NPO (the North Pacific Oscillation) and interdecadal climate variation in China, the interdecadal variation of the East Asian monsoon, the interdecadal mode of SSTA (Sea Surface Temperature Anomaly) in the North Pacific and its climate impact, and abrupt change feature of the climate.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3209800)the National Natural Science Foundation of China(Grant No.52279011).
文摘In the context of climate change,the acceleration of the global water cycle has led to the emergence of abrupt transitions between drought and flood events,presenting a new challenge for flood and drought disaster mitigation.Abrupt transitions between drought and flood refer to a phenomenon in which an extreme drought event quickly shifts to an extreme flood event,or vice versa,within a relatively short time span.This phenomenon disrupts the traditional spatiotemporal distribution patterns of water-related disasters,reflecting not only the extreme unevenness in the distribution of water resources but also the rapid alternation of the water cycle's evolution(He et al.,2016).Moreover,due to its suddenness,extremity,and complexity,it poses severe threats to human societies and ecosystems.Scientifically addressing abrupt transitions between drought and flood has thus become a new challenge in flood and drought disaster prevention.
基金supported by the National Natural Science Foundation of China(No.52107125)Applied Basic Research Project of Sichuan Province(No.2022NSFSC0250)Chengdu Guojia Electrical Engineering Co.,Ltd.(No.KYL202312-0043).
文摘Critical for metering and protection in electric railway traction power supply systems(TPSSs),the measurement performance of voltage transformers(VTs)must be timely and reliably monitored.This paper outlines a three-step,RMS data only method for evaluating VTs in TPSSs.First,a kernel principal component analysis approach is used to diagnose the VT exhibiting significant measurement deviations over time,mitigating the influence of stochastic fluctuations in traction loads.Second,a back propagation neural network is employed to continuously estimate the measurement deviations of the targeted VT.Third,a trend analysis method is developed to assess the evolution of the measurement performance of VTs.Case studies conducted on field data from an operational TPSS demonstrate the effectiveness of the proposed method in detecting VTs with measurement deviations exceeding 1%relative to their original accuracy levels.Additionally,the method accurately tracks deviation trends,enabling the identification of potential early-stage faults in VTs and helping prevent significant economic losses in TPSS operations.
基金supported by the National Natural Science Foundation of China (Grant Nos.42005029 and 41701103)the China Meteorological Administration Special Foundation for Innovation and Development (Grant No.CXFZ2024Q007)。
文摘In the summer of 2024, following a strong El Ni?o event in the preceding winter, the tropical Indian Ocean and tropical North Atlantic recorded their highest SSTs since 1961, along with a significant westward shift and intensification of the western Pacific subtropical high(WPSH). Under these conditions, China experienced its hottest summer since 1961,and was hit by a series of high-impact extreme weather and climate events. From 9 June to 2 July, southern China experienced an unprecedented extreme precipitation event that exceeded the well-known 1998 summer precipitation event in both duration and impact scope, resulting in devastating floods in the Yangtze River basin. Subsequently, in early to midJuly, the Huanghe-Huaihe Basin suffered from a severe drought–flood abrupt alternation event, heavily affecting Henan and Shandong. Meanwhile, southern China underwent a widespread heatwave event lasting 74 days, ranking as the second most intense since 1961. From late July to the end of August, northern China faced unusually frequent heavy precipitation events, with cumulative precipitation reaching the second highest for the same period since 1961, causing floods in many rivers of northern China. This study provides a timely summary and assessment of the characteristics and impacts of these extreme events. It serves as a reference for climate change research, including mechanism analysis, numerical simulation,and climate event attribution, and also offers valuable insights for improving meteorological disaster prevention and mitigation strategies.
基金supported by the National Natural Science Foundation of China[grant numbers U2142207 and U2342205]the National Key R&D Program of China[grant number 2024YFC3013100]China Meteorological Administration(CMA)Youth Innovation Team[CMA2024QN06].
文摘Since the 21st century,the Huang–Huai–Hai River Basin(HHHRB)in China has experienced increased frequency and severity of drought–flood abrupt alternation(DFAA)events during early summer,characterized by droughts in June followed by floods in July.The 2024 event was the most severe since 1981.This study demonstrates that such compound extreme events are closely linked to anomalous subseasonal evolution of large-scale atmospheric circulation.During the drought phase,the East Asian subtropical westerly jet(EAJ)shifts southward,and the western Pacific subtropical high(WPSH)exhibits anomalous strengthening with its western ridge line displaced southward.The flood phase is characterized by acceleration of the EAJ,westward extension of the WPSH,and enhanced southwestern moisture transport from the western Pacific.Beyond these typical features,the 2024 early summer circulation exhibited unique characteristics:Anomalous northeastward intensification of the WPSH facilitated merged moisture influx from both the Indian Ocean and the western Pacific along the southeast pathway into the HHHRB in July,resulting in the highest net moisture inflow at the southern boundary of the HHHRB since 1981.The synergistic effects of multiple factors primarily explain the exceptionally intense DFAA event in 2024.
文摘It is an objective fact that the weather is unpredictable.Even the famous meteorologist,Academician Chu Ko Chen,has only a partial understanding of the changing laws of wind and rain.Even though ancient people summarized the 24 solar terms by observing the annual activities of the sun for a long time,because they ignored the impact of the activities of the moon on the Earth’s climate change on a small scale,the 24 solar terms they summarized often could not accurately predict the change of the Earth’s climate.Therefore,the author studied the influence of lunar activities on the Earth’s climate change,finds out the law of the influence of lunar activities on the Earth’s climate change on a small scale,and summarizes the eternal climate change pattern determined by the activities of the sun and the moon.In addition,the author also reveals the causes and countermeasures of global warming and the frequent occurrence of extreme weather as well as environmental change.
文摘Climate change is the phrase used to describe long-term changes in temperatures and weather patterns. Changes in the atmosphere and their interactions with diverse geologic, chemical, biological, and geographic variables are the main contributors to this cyclical adjustment of the Earth’s climate. Such changes may be induced purposefully, because of burning fossil fuels, clearing forests, and raising animals, or they may be natural, brought on by significant volcanic eruptions or variations in the sun’s activity. By significantly increasing the amount of greenhouse gases already in the atmosphere, this heightens the greenhouse effect and contributes to global warming. This work includes several additional theoretical and practical explanations of sustainable development. The theoretical work encompasses hundreds of researches that identify requirements for how development routes might satisfy sustainable development (SD) criteria using economic theory, complex systems approach, ecological science, and other techniques. The agreements made by the Parties in various nations across the world will consider a wide range of perspectives about what would be considered undesirable effects on the environment, the climate system, sustainability, economic growth, or food production.
文摘The effect of pruning severity on tree growth was analyzed by change point detection using segmented regression. The present study applied this analysis to a well-known published data set including diameter growth response, tree age, pruning severity and pretreatment crown size. First, multiple regression analysis was performed to assess the effect of tree age, pruning severity and pretreatment crown size on diameter growth response. Next, segmented regression analysis was performed to assess the effect of pruning severity on diameter growth response. The results of the multiple regression showed that diameter growth response was significantly influenced by pruning severity and pretreatment crown size. The results of the segmented regression showed that in the whole data set, an abrupt change toward a decrease in diameter growth response was detected at 25% of the live crown removed. However, in the group of fully crowned and open-grown, diameter growth response continuously decreased with increasing pruning severity with no significant abrupt change, whereas in the group of 70% - 90% live crown, diameter growth response did not significantly decrease up to the break point (53% crown removed) and then abruptly decreased. This may be the first study to show the numerical evaluation of the effect of pruning severity on tree growth by change point analysis.
基金Supported by National Key Technology R&D Program(2007BAC-29B02)
文摘Based on the monthly precipitation data from 43 stations in North China from 1979 to 2008,the variation characteristics of precipitation in North China in recent 30 years were analyzed by means of empirical orthogonal function(EOF)decomposition,Morlet wavelet transform and Mann-Kendall test.The results showed that the spatial distribution of annual and seasonal precipitation was basically identical in North China,while the annual and summer precipitation from the middle of 1980s to the middle of 1990s were obviously more than these in other periods,and there was great annual variation in spring precipitation in 1990s,while autumn precipitation was higher from 1980s to 1990s and then went down after the beginning of 21st century,which was opposite to winter precipitation,namely there was more winter precipitation from 1980s to 1990s and fewer winter precipitation after the beginning of 21st century.In addition,the annual and summer precipitation changed abruptly in 1997,and there was no obvious change in spring precipitation and autumn precipitation,while winter precipitation had an abrupt change in 2000.Meanwhile,wavelet analysis revealed that the variation period of annual and seasonal precipitation was 3-4 years.
基金Supported by National Natural Science Foundation of China (40971294)Science and Technology Planning Project of Dalian Science and Technology Bureau(2009E11SF230)~~
文摘[Objective] The change law and meteorological factor of sunshine duration in Dalian in recent 60 years were studied.[Method] Based on the statistical data of sunshine duration from base station in Dalian City from 1951 to 2009,the annual,seasonal,and monthly variation of sunshine duration in recent 60 years were analyzed,as well as its relationship with meteorological factors,and sunshine duration was detected by means of climate mutation theory.[Result] Annual sunshine duration in Dalian in recent 60 years showed decrease trend on the whole,and its climatic variation rate was-3.31 h/a,with larger annual variation,namely the difference between maximum value(1978) and minimum value(2003) reached 681 h;there was obvious seasonal variation in sunshine duration,with the order of autumn>summer>winter>spring,and their climatic variation rate were-1.18,-1.15,-0.91 and-0.62 h/a;except for March,sunshine duration in each month went down,especially October,while there was slight increase in March;sunshine percentage had inverse correlation relationship with total cloudiness,relative humidity and heavy fog days;annual sunshine duration reduced abruptly around 1983.[Conclusion] Our study could provide scientific foundation for the development of agriculture and forestry in Dalian City.
基金Supported by Key Project of Hunan Meteorological Bureau "Study on Formation Mechanism and Report Method Based on Comprehensive Meteorological Data"
文摘[Objective] The aim is to expound the abrupt rainstorm in the central Hunan Province on May 6 in 2010.[Method] By dint of NCEP 1°×1° reanalysis data,routine observation data,auto-station precipitation and FY-2C satellite data,the large-scale circulation background and physical condition during the large rainstorm period from the night on May 5 to 6 in 2010 were analyzed.The large scale environment,meso-scale characteristics and potential causes for the formation of large precipitation were revealed.By dint of FY-2D satellite and water-vapor cloud image,infrared cloud image,4 black light temperature,the variation characteristics of heavy rainstorm convection system were analyzed.[Result] Under the favorable environment background,the rainstorm was induced by the meso-scale convection system,and it had close relation with the upper-air trough,shear line in the middle and low layer,ground weak and cold air and the torrent in the upper and low latitude.The result of all kinds of physical quantities suggested that the meso-scale rainstorm above the air had distinct characteristics and the heavy precipitation was in the middle Hunan Province.It was caused by meso-system.The dynamic dry belt above the satellite,TBB=-60℃ center and the large value area of the gradient could provide references for the forecast and pre-warning of large rainstorm.[Conclusion] The study accumulated experiences for the forecast and report of rainstorm in Hunan Province.
文摘A great amount of results obtained from the experiments carried out by a number of scientists and by us especially have been subjected to modeling which enabled to implement analysis according to the method of dialectics ＂cause^-~consequence＂. A variety of numerous factors （chemical, physical, etc.） that engender the same biological process have been characterized by a single vector-energy （E） which along with the time （T） parameter defines the dose： D （dose） = E （energy） x T （time）. Dose （D） as a cause and biological process as a consequence revealed a number of interrelated regularities such as discontinuity, continuity, homogeneity, heterogeneity, relativity, successiveness, abruptness, spontaneity and correlation between biological processes. Thus, the life cycle in vivo was based on these regularities. Besides, these regularities are necessary and sufficient to prove biologically the bioprocess realized by the mechanism of ＂quantum theory＂.
文摘[Objective] The aim was to study the characteristics of temperature changes in Liupanshui in recent 50 years. [Method] Based on the monthly temperature data from 3 observational stations in Liupanshui from 1960 to 2009 and by employing the linear method and Mann-Kendall method, features and abrupt changes of temperature in Liupanshui were discussed. [Result] The results indicated the temperature in Liu Panshui increased obviously in recent 50 years at a rate of 0.096 ℃/10 a. Average temperature in spring was decreasing, but was increasing in summer, autumn and winter at different rate. The average temperature changed the most in winter, followed by summer and autumn and changed the least in spring. The temperature changes were not distinct before the early 1980s. Temperature increased significantly after 80s, having distinct waving nature and several mutation points. The distinct mutation point appeared in 1978 and the annual average temperature increased significantly after 1978. There was no obvious mutation of temperature in spring; the mutation points of temperature in summer, autumn and winter were 1978, 1982 and 1985. [Conclusion] The study provided reference for the short term forecast of climate in Liupanshui City.
基金Supported by National Key Technology R&D Program(2007BAC29B03)
文摘By means of linear function and Mann-Kendall test method,the climate change characteristics of temperature and precipitation from Zhumadian meteorological station in recent 50 years were analyzed.The results revealed that annual mean temperature and extreme temperature showed increase trend,especially minimum temperature,and there was a slight increase in annual precipitation.Temperature increase was more obvious in spring than that in autumn and winter,while there was a decrease of temperature in summer.Meanwhile,precipitation went down in spring and autumn,particular in autumn,while the increase of summer precipitation was most obvious.Mann-Kendall test showed that temperature in Zhumadian had obvious increase trend in recent 50 years,while there was abrupt change in temperature in the late 1990s and fluctuation change in annual precipitation.
文摘[Objective] The aim was to analyse the variation characteristics of temperature in Anqing City and urban heat island effect.[Method] Based on the observation data of temperature from Anqing Station,other surrounding meteorological stations and local automatic meteorological stations in suburbs,the annual variation of temperature and regional consistency was analysed,then the abrupt change of annual average temperature was tested by Mann-Kendall test,finally the influences of urban heat island effect on temperature variation in Anqing Station were studied.[Result] Affected by station migration and urban construction,the annual average temperature increased significantly in Anqing Station from 1977 to 2009,and the rising was more prominent after the middle of the 1990s.Mann-Kendall test showed that the change of temperature in Anqing Station was obviously abrupt around 1993;because of the development of urbanization,average temperature in Anqing Station was 0.8 ℃ higher than that in suburbs,and the minimum temperature rose more remarkably.In addition,urban heat island effect was the strongest in spring,followed by summer and autumn,while it was the weakest in winter.[Conclusion] The effects of urbanization development on the temperature in Anqing City were understood through this research.
基金Supported by National Key Basic Research Development Program of China(2010CB951003,2007CB411501)Knowledge Innovation Program of Chinese Academy of Sciences(KZCX2-EW-311,KZCX2-YW127)+2 种基金Project Funded by National Natural Science Foundation of China(40631001,9102501240571033,40701034,40371028, J0630966,40701035)Autonomous Subject of State Key Laboratory of Cryospheric Sciences(SKLCS-ZZ-2010-04)~~
文摘Based on the meteorological data during 1959-2008 from five representative weather stations in the Urumqi River Basin and surrounding areas,the regional characteristics of temperature and precipitation in the basin featuring multi-climatic zones were studied by means of some methods including wavelet analysis.As was shown in the results,the temperature in the whole Urumqi River Basin demonstrated a significant upward trend.The temperature increase particularly in autumn and winter made the greatest contribution to the marked ascent.The interdecadal temperature in the basin showed a tendency to decline before the period during 1970s-1980s while it was on the rise after 1990s on the whole.The most concentrated period of temperature mutations was in the late 1990s.At the same time,the precipitation also showed an escalating trend,which experienced a stage of unanimous upward trend after 1990s.The most concentrated period of precipitation mutations was in the early 1990s.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10774062, 10774061 and 90505007. The authors thank Y. D. Zhang and D. P. Yang for fruitful discussions.
文摘With an effective bianisotropy picture, high-frequency behaviours of different magnetic materials can be reconciled, and the higher permeability and higher resonance frequencies are achieved even in the GHz range. The validity of the bianisotropy picture is quantitatively verified by the in-plane anisotropic Fe34Co55Zr11 thin films. A prolate elliptical precession of the magnetization about its equilibrium direction is the key point, which can be induced by an artificial or an intrinsic bianisotropy system.
基金National Natural Science Foundation of China,No.41630859The CAS "Light of West China" Program,No.2015-XBQN-B-17
文摘Under the impacts of climate change and human activities, great uncertainties still exist in the response of climate extremes, especially in Central Asia (CA). In this study, we investigated spatial-temporal variation trends and abrupt changes in 17 indices of climate extremes, based on daily climate observations from 55 meteorological stations in CA during 1957-2005. We also speculated as to which atmospheric circulation factors had the greatest impacts on climate extremes. Our results indicated that the annual mean temperature (Tav), mean maximum and minimum temperature significantly increased at a rate of 0.32ºC/10a, 0.24ºC/10a and 0.41ºC/10a, respectively, which was far higher than the increasing rates either globally or across the Northern Hemisphere. Other temperature extremes showed widespread significant warming trends, especially for those indices derived from daily minimum temperature. All temperature extremes exhibited spatially widespread rising trends. Compared to temperature changes, precipitation extremes showed higher spatial and temporal variabilities. The annual total precipitation significantly increased at a rate of 4.76 mm/10a, and all precipitation extremes showed rising trends except for annual maximum consecutive dry days (CDD), which significantly decreased at a rate of -3.17 days/10a. On the whole, precipitation extremes experienced slight wetter trends in the Tianshan Mountains, Kazakhskiy Melkosopochnik (Hill), the Kyzylkum Desert and most of Xinjiang. The results of Cumulative Deviation showed that Tav and Txav had a significant abrupt change around 1987, and all precipitation indices experienced abrupt changes in 1986. Spearman’s correlation analysis pointed to Siberian High and Tibetan Plateau Index_B as possibly being the most important atmospheric circulation factors affecting climate extremes in CA. A full quantitative understanding of these changes is crucial for the management and mitigation of natural hazards in this region.
基金Supported by the Natural Science Foundation of Shandong Province under Grant No Q2005A01.
文摘Employing the compatibility method, we obtain the symmetries of the （3＋1）-dimensional Kadomtsev Petviashvili （KP） equation. Four types of similarity reductions of the KP equation are obtained by solving the corresponding characteristic equations associated with symmetry equations. In addition, a lot of similarity solutions to the KP equation are obtadned.
基金supported by the National Natural Science Foundation of China(Grant No.40233033)the Chinese Academy of Sciences(ZKCX2-SW-210 and KZCX2-203).
文摘Decadal/interdecadal climate variability is an important element in the CLIVAR (Climate Variability and Predictability) and has received much attention in the world. Many studies in relation to interdecadal variation have also been completed by Chinese scientists in recent years. In this paper, an introduction in outline for interdecadal climate variation research in China is presented. The content includes the features of interdecadal climate variability in China, global warming and interdecadal temperature variability, the NAO (the North Atlantic Oscillation)/NPO (the North Pacific Oscillation) and interdecadal climate variation in China, the interdecadal variation of the East Asian monsoon, the interdecadal mode of SSTA (Sea Surface Temperature Anomaly) in the North Pacific and its climate impact, and abrupt change feature of the climate.
