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Impact of initial fluctuations and nuclear deformations in isobar collisions
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作者 Jian-Fei Wang Hao-Jie Xu Fu-Qiang Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第6期155-162,共8页
Relativistic isobar^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zrcollisions have revealed intricate differences in their nuclear size and shape,inspiring unconventional studies of nuclear structure using relat... Relativistic isobar^(96)_(44)Ru+^(96)_(44)Ru and^(96)_(40)Zr+^(96)_(40)Zrcollisions have revealed intricate differences in their nuclear size and shape,inspiring unconventional studies of nuclear structure using relativistic heavy ion collisions.In this study,we investigate the relative differences in the mean multiplicityR_(<Nch>)and the secondR_(ε2)and third-order eccentricityR_(ε3)between isobar collisions using initial state Glauber models.It is found that initial fluctuations and nuclear deformations have negligible effects on R_(<Nch>)in most central collisions,while both are important for the R_(ε2)and R_(ε3),the degree of which is sensitive to the underlying nucleonic or sub-nucleonic degree of freedom.These features,compared to real data,may probe the particle production mechanism and the physics underlying nuclear structure. 展开更多
关键词 Relativistic isobar collisions Initial fluctuations Nuclear deformation
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Optimization of Gas Production from Hydrate-Bearing Sediments with Fluctuation Characteristics
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作者 LI Yaobin XU Tianfu +3 位作者 XIN Xin YU Han YUAN Yilong ZHU Huixing 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第3期618-632,共15页
As an important source of low-carbon,clean fossil energy,natural gas hydrate plays an important role in improving the global energy consumption structure.Developing the hydrate industry in the South China Sea is impor... As an important source of low-carbon,clean fossil energy,natural gas hydrate plays an important role in improving the global energy consumption structure.Developing the hydrate industry in the South China Sea is important to achieving‘carbon peak and carbon neutrality’goals as soon as possible.Deep-water areas subjected to the action of long-term stress and tectonic movement have developed complex and volatile terrains,and as such,the morphologies of hydrate-bearing sediments(HBSs)fluctuate correspondingly.The key to numerically simulating HBS morphologies is the establishment of the conceptual model,which represents the objective and real description of the actual geological body.However,current numerical simulation models have characterized HBSs into horizontal strata without considering the fluctuation characteristics.Simply representing the HBS as a horizontal element reduces simulation accuracy.Therefore,the commonly used horizontal HBS model and a model considering the HBS’s fluctuation characteristics with the data of the SH2 site in the Shenhu Sea area were first constructed in this paper.Then,their production behaviors were compared,and the huge impact of the fluctuation characteristics on HBS production was determined.On this basis,the key parameters affecting the depressurization production of the fluctuating HBSs were studied and optimized.The research results show that the fluctuation characteristics have an obvious influence on the hydrate production of HBSs by affecting their temperatures and pressure distributions,as well as the transmission of the pressure drop and methane gas discharge.Furthermore,the results show that the gas productivity of fluctuating HBSs was about 5%less than that of horizontal HBSs.By optimizing the depressurization amplitude,well length,and layout location of vertical wells,the productivity of fluctuating HBSs increased by about 56.6%. 展开更多
关键词 natural gas hydrate numerical simulation fluctuation characteristics depressurization production production well optimization
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Climatic implications in earlywood and latewood width indices of Chinese pine in north central China
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作者 Kaixuan Yang Junzhou Zhang +1 位作者 Haowen Fan Yuan Yan 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期143-153,共11页
Latewood width(LWW)indices of trees are considered a reliable proxy of summer precipitation in the Northern Hemisphere.However,the strong coupling and high correlation between earlywood width(EWW)and LWW indices often... Latewood width(LWW)indices of trees are considered a reliable proxy of summer precipitation in the Northern Hemisphere.However,the strong coupling and high correlation between earlywood width(EWW)and LWW indices often prevent registration of climate signals of the LWW index.In this study,328-year-long earlywood width and latewood width chronologies were developed from Chinese pine at two sites in the Hasi Mountains,north central China.The climate responses of these chronologies were analyzed and the LWW index used to derive sum-mer precipitation signals.Correlation analyses showed that LWW was particularly influenced by earlywood growth and recorded stronger climate signals of the previous year as EWW,rather than those of the current year with infrequent summer climate signals.However,after removing the effect of earlywood growth using a simple regression model,the adjusted LWW chronology(LWW_(adj))showed a strong relationship with July precipitation in dry years.This suggests that the LWW_(adj) chronology has the potential to be used to investigate long-term variability in summer precipitation in drought-limited regions. 展开更多
关键词 DENDROclimatOLOGY Latewood width climate response Summer precipitation Earlywood effect
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Experimental study on temperature fluctuations on plate surface induced by coaxial-jet flow
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作者 Xue-Yao Xiong Zun-Quan Liu +2 位作者 Guo-Yan Zhou Xing Luo Shan-Tung Tu 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第5期139-153,共15页
In nuclear reactors,temperature fluctuations of fluids may cause fatigue damage to adjacent structures;this is referred to as thermal striping.Research on thermal striping in the upper plenum has mainly focused on flu... In nuclear reactors,temperature fluctuations of fluids may cause fatigue damage to adjacent structures;this is referred to as thermal striping.Research on thermal striping in the upper plenum has mainly focused on fluid fields.Few experimental studies have been reported on solid structures in a fluid field with a coaxial jet.This study entailed an experimental study of the temperature fluctuations in the fluid and on a plate surface caused by a coaxial jet.The temperature fluctuations of the fluid and plate surfaces located at different heights were analyzed.The cause of the temperature fluctuation was analyzed using a transient temperature distribution.The results show that the mixing of the hot and cold fluids gradually becomes uniform in the positive axial direction.The average surface temperatures tended to be consistent.When the jet reaches the plate surface,the swing of the jet center,contraction and expansion of the cold jet,and changes in the jet shape result in temperature fluctuations.The intensity of the temperature fluctuation was affected by the position.More attention should be paid when the plate is located at a lower height,and between the hot and cold-fluid nozzles. 展开更多
关键词 Temperature fluctuation Thermal striping Coaxial jet Thermal mixing The upper plenum of nuclear reactor
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Research on Anti-Fluctuation Control of Winding Tension System Based on Feedforward Compensation
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作者 Yujie Duan Jianguo Liang +4 位作者 Jianglin Liu Haifeng Gao Yinhui Li Jinzhu Zhang Xinyu Wen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1239-1261,共23页
In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tens... In the fiber winding process,strong disturbance,uncertainty,strong coupling,and fiber friction complicate the winding constant tension control.In order to effectively reduce the influence of these problems on the tension output,this paper proposed a tension fluctuation rejection strategy based on feedforward compensation.In addition to the bias harmonic curve of the unknown state,the tension fluctuation also contains the influence of bounded noise.A tension fluctuation observer(TFO)is designed to cancel the uncertain periodic signal,in which the frequency generator is used to estimate the critical parameter information.Then,the fluctuation signal is reconstructed by a third-order auxiliary filter.The estimated signal feedforward compensates for the actual tension fluctuation.Furthermore,a time-varying parameters fractional-order PID controller(TPFOPID)is realized to attenuate the bounded noise in the fluctuation.Finally,TPFOPID is enhanced by TFO and applied to control a tension control system considering multi-source disturbances.The stability of the method is analyzed by using the Lyapunov theorem.Finally,numerical simulations verify that the proposed scheme improves the tracking ability and robustness of the system in response to tension fluctuations. 展开更多
关键词 Constant tension control anti-fluctuation strategy tension fluctuation observer time-varying parameters fractional-order PID controller feedforward compensate
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Influence of blood glucose fluctuations on chemotherapy efficacy and safety in type 2 diabetes mellitus patients complicated with lung carcinoma
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作者 Tian-Zheng Fang Xian-Qiao Wu +4 位作者 Ting-Qi Zhao Shan-Shan Wang Guo-Mei-Zhi Fu Qing-Long Wu Cheng-Wei Zhou 《World Journal of Diabetes》 SCIE 2024年第4期645-653,共9页
BACKGROUND Patients with type 2 diabetes mellitus(T2DM)have large fluctuations in blood glucose(BG),abnormal metabolic function and low immunity to varying degrees,which increases the risk of malignant tumor diseases ... BACKGROUND Patients with type 2 diabetes mellitus(T2DM)have large fluctuations in blood glucose(BG),abnormal metabolic function and low immunity to varying degrees,which increases the risk of malignant tumor diseases and affects the efficacy of tumor chemotherapy.Controlling hyperglycemia may have important therapeutic implications for cancer patients.AIM To clarify the influence of BG fluctuations on chemotherapy efficacy and safety in T2DM patients complicated with lung carcinoma(LC).METHODS The clinical data of 60 T2DM+LC patients who presented to the First Affiliated Hospital of Ningbo University between January 2019 and January 2021 were retrospectively analyzed.All patients underwent chemotherapy and were grouped as a control group(CG;normal BG fluctuation with a mean fluctuation<3.9 mmol/L)and an observation group(OG;high BG fluctuation with a mean fluctuation≥3.9 mmol/L)based on their BG fluctuations,with 30 cases each.BGrelated indices,tumor markers,serum inflammatory cytokines and adverse reactions were comparatively analyzed.Pearson correlation analysis was performed to analyze the correlation between BG fluctuations and tumor markers.RESULTS The fasting blood glucose and 2-hour postprandial blood glucose levels in the OG were notably elevated compared with those in the CG,together with markedly higher mean amplitude of glycemic excursions(MAGE),mean of daily differences,largest amplitude of glycemic excursions and standard deviation of blood glucose(P<0.05).In addition,the OG exhibited evidently higher levels of carbohydrate antigen 19-9,carbohydrate antigen 125,carcinoembryonic antigen,neuron-specific enolase,cytokeratin 19,tumor necrosis factor-α,interleukin-6,and highsensitivity C-reactive protein than the CG(P<0.05).Pearson analysis revealed a positive association of MAGE with serum tumor markers.The incidence of adverse reactions was significantly higher in the OG than in the CG(P<0.05).CONCLUSION The greater the BG fluctuation in LC patients after chemotherapy,the more unfavorable the therapeutic effect of chemotherapy;the higher the level of tumor markers and inflammatory cytokines,the more adverse reactions the patient experiences. 展开更多
关键词 Blood glucose fluctuation Type 2 diabetes mellitus Lung carcinoma Tumor markers
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Assessment of rehabilitation strategies for lakes affected by anthropogenic and climatic changes: A case study of the Urmia Lake, Iran
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作者 Seyed Morteza MOUSAVI Hossein BABAZADEH +1 位作者 Mahdi SARAI-TABRIZI Amir KHOSROJERDI 《Journal of Arid Land》 SCIE CSCD 2024年第6期752-767,共16页
Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other h... Over the last three decades,more than half of the world's large lakes and wetlands have experienced significant shrinkage,primarily due to climate change and extensive water consumption for agriculture and other human needs.The desiccation of lakes leads to severe environmental,economic,and social repercussions.Urmia Lake,located in northwestern Iran and representing a vital natural ecosystem,has experienced a volume reduction of over 90.0%.Our research evaluated diverse water management strategies within the Urmia Lake basin and prospects of inter-basin water transfers.This study focused on strategies to safeguard the environmental water rights of the Urmia Lake by utilizing the modeling and simulating(MODSIM)model.The model simulated changes in the lake's water volume under various scenarios.These included diverting water from incoming rivers,cutting agricultural water use by 40.0%,releasing dam water in non-agricultural seasons,treated wastewater utilization,and inter-basin transfers.Analytical hierarchy process(AHP)was utilized to analyze the simulation results.Expert opinions with AHP analysis,acted as a multi-criteria decision-making tool to evaluate the simulation and determine the optimal water supply source priority for the Urmia Lake.Our findings underscore the critical importance of reducing agricultural water consumption as the foremost step in preserving the lake.Following this,inter-basin water transfers are suggested,with a detailed consideration of the inherent challenges and limitations faced by the source watersheds.It is imperative to conduct assessments on the impacts of these transfers on the downstream users and the potential environmental risks,advocating for a diplomatic and cooperative approach with adjacent country.This study also aims to forecast the volumes of water that can be transferred under different climatic conditions—drought,normal,and wet years—to inform strategic water management planning for the Urmia Lake.According to our projection,implementing the strategic scenarios outlined could significantly augment the lake's level and volume,potentially by 3.57×109–9.38×109 m3 over the coming 10 a and 3.57×109–10.70×109 m3 in the subsequent 15 a. 展开更多
关键词 climate change DROUGHT lake ecological level agricultural water demand inter-basin water transfer
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Trade-Offs and Synergie Effects of Regulating Ecosystem Services along an Climatic Gradient in Slovakia
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作者 Jarmila Makovníková Stanislav Kološta Boris Pálka 《Journal of Geoscience and Environment Protection》 2024年第6期135-150,共16页
This study aims to assess the synergies and trade-offs of regulating ecosystem services. Ecosystem services are non-linearly interconnected and changes in one service can positively or negatively affect another. We ev... This study aims to assess the synergies and trade-offs of regulating ecosystem services. Ecosystem services are non-linearly interconnected and changes in one service can positively or negatively affect another. We evaluated ecosystem services based on biophysical indicators using an expert scoring system that determines the corresponding soil functions and is part of the existing databases available in Slovakia. This methodological combination enabled us to provide unique mapping and assessment of ecosystem services within Slovakia. Correlation analysis between individual regulating ecosystem services and climate regions, slope, texture, and altitude confirm the statistically significant influence of climate and slope in all agricultural land, arable land, and grassland ecosystems. Statistically significant synergistic effects were established between the regulation of the water regime and the regulation of soil erosion within each climate region, apart from the very warm climate region. Only in a very warm climate region was potential of regulating ecosystem services mutually beneficial for soil erosion control and soil cleaning potential (immobilization of inorganic pollutants). 展开更多
关键词 Agroecosystem Services climatic Zone MAPPING Trade-Offs SYNERGIES
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Numerical Models and Methods of Atmospheric Parameters Originating in the Formation of the Earth’s Climatic Cycle
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作者 Wend Dolean Arsène Ilboudo Kassoum Yamba +1 位作者 Windé Nongué Daniel Koumbem Issaka Ouédraogo 《Atmospheric and Climate Sciences》 2024年第2期277-286,共10页
Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model o... Atmospheric models are physical equations based on the ideal gas law. Applied to the atmosphere, this law yields equations for water, vapor (gas), ice, air, humidity, dryness, fire, and heat, thus defining the model of key atmospheric parameters. The distribution of these parameters across the entire planet Earth is the origin of the formation of the climatic cycle, which is a normal climatic variation. To do this, the Earth is divided into eight (8) parts according to the number of key parameters to be defined in a physical representation of the model. Following this distribution, numerical models calculate the constants for the formation of water, vapor, ice, dryness, thermal energy (fire), heat, air, and humidity. These models vary in complexity depending on the indirect trigonometric direction and simplicity in the sum of neighboring models. Note that the constants obtained from the equations yield 275.156˚K (2.006˚C) for water, 273.1596˚K (0.00963˚C) for vapor, 273.1633˚K (0.0133˚C) for ice, 0.00365 in/s for atmospheric dryness, 1.996 in<sup>2</sup>/s for humidity, 2.993 in<sup>2</sup>/s for air, 1 J for thermal energy of fire, and 0.9963 J for heat. In summary, this study aims to define the main parameters and natural phenomena contributing to the modification of planetary climate. . 展开更多
关键词 Atmospheric Parameter 1 climatic Cycle 2 Numerical Models 3
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Climatic drivers of the Canadian wildfire episode in 2023
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作者 Yihan Hu Xu Yue Chenguang Tian 《Atmospheric and Oceanic Science Letters》 CSCD 2024年第4期23-28,共6页
2023年5月加拿大发生极端野火事件并持续4个月时间.野火污染物排放对当地和下风向的空气质量造成了严重影响.本文对驱动此次野火事件的气象因子和相关大尺度环流进行了探究.研究表明,此次极端野火排放的二氧化碳相较往年同期增长了0.37G... 2023年5月加拿大发生极端野火事件并持续4个月时间.野火污染物排放对当地和下风向的空气质量造成了严重影响.本文对驱动此次野火事件的气象因子和相关大尺度环流进行了探究.研究表明,此次极端野火排放的二氧化碳相较往年同期增长了0.37Gt (527.1%).受罗斯贝波频散影响,同期加拿大中西部区域出现持续的位势高度正异常,促进气流下沉并引发局地高温,中西部区域5-6月最高温平均上升8.11℃,部分区域甚至超过10℃,导致野火排放的显著增长.受有利地形和泛北极地区快速增暖的影响,预期未来加拿大中西部发生极端野火的概率可能会显著上升. 展开更多
关键词 野火 气候变化 遥相关 极端天气 碳排放
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Influence of climate fluctuations on Pinus palustris growth and drought resilience
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作者 Joao Campoa Joshua Puhlick 《Forest Ecosystems》 SCIE CSCD 2023年第6期681-689,共9页
The longleaf pine(Pinus palustris Mill.)ecosystem is an endangered ecosystem in the southeastern USA,and efforts to restore the species are ongoing.However,in recent decades,the region has experienced drastic fluctuat... The longleaf pine(Pinus palustris Mill.)ecosystem is an endangered ecosystem in the southeastern USA,and efforts to restore the species are ongoing.However,in recent decades,the region has experienced drastic fluctuations between wet and dry growing season conditions from year to year,and it is not fully understood how these fluctuations have influenced the growth of P.palustris.To address this topic,we cored P.palustris trees in woodlands of southwest Georgia and used dendrochronology techniques to determine how climate fluctuations have influenced the growth and drought resilience of P.palustris.We also cored slash pine(Pinus elliottii Engelm.)trees in the same woodlands to compare growth between species.While P.palustris growth was less impacted by adverse climate conditions compared to P.elliottii,the strength of correlations between P.palustris growth and temperature,precipitation,and Palmer Drought Severity Index(PDSI)changed over time.In recent decades,climate conditions during the growing season became more influential on P.palustris growth than the previous year's conditions.This is concerning given that drought severity during the growing season has been increasing.Our results also indicate that P.palustris was less resilient to droughts during the 2000s and 2010s than to those of the 1950s.Under this new climate paradigm,our results suggest that P.palustris might be more susceptible to growth reductions and less resistant to droughts than once expected.This work highlights the importance of understanding the impact of novel climate conditions on P.palustris and has implications for restoration efforts,such as using silvicultural treatments that reduce tree vulnerability to drought(e.g.,thinning)and promote other climate-adapted species in mixture with P.palustris. 展开更多
关键词 Longleaf pine Slash pine Pinus elliottii climate change Dendrochronology DENDROclimatOLOGY Forest disturbances
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A Multi-cycle Climatic Fluctuation Record of the Last Interglacial Period:Typical Stratigraphic Section in the Salawusu River Valley on the Ordos Plateau,China 被引量:23
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作者 LIBaosheng DavidDianZHANG +3 位作者 WENXiaohao DONGYuxiang ZHUYizhi JINHeling 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2005年第3期398-404,共7页
The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies... The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies and paleosols. Based on comprehensive analyses on the distribution of magnetic susceptibility and CaCO3 and paleo-ecology indicated by fossils in the region, it is considered that the sedimentation cycles resulted from dry-cold and warm-humid climate fluctuations. Magnetic susceptibility values and CaCO3 contents in stratigraphic sectors I, III, V and II, IV basically respectively present peaks and low vales, and the former three can in time correlate with MIS5a, MIS5c and MIS5e successively and the latter two with MIS5b and MIS5d. In addition, some horizons of eolian dune sands and the low vales of their magnetic susceptibility and CaCO3 are also correlated with 6 periods of cooling events indicated by the higher content of foraminifer Neogloboquadrina pachyderma (S.) documented in the V29—191 drill in the North Atlantic and the cold events recorded by δ 18O in the ice cores in GRIP, especially with 9 periods of dust events in Chinese Loess Plateau. 展开更多
关键词 last interglacial period dune events cold-warm climate cycles Salawusu River valley Inner Mongolia
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THE RELATIONSHIP BETWEEN INLAND LAKES EVOLUTION AND CLIMATIC FLUCTUATION IN ARID ZONE 被引量:1
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作者 秦伯强 施雅风 王苏民 《Chinese Geographical Science》 SCIE CSCD 1991年第4期26-33,共8页
The evolution of the inland lakes in arid and semi-arid zones is accorded with the climatic fluctuation. The humid climate is in harmony with the higher water level and greater lake water quantity budget while arid cl... The evolution of the inland lakes in arid and semi-arid zones is accorded with the climatic fluctuation. The humid climate is in harmony with the higher water level and greater lake water quantity budget while arid climate is in correspondence with the lower water level and little water budget. Based on the analysis of the lake fluctuation and lake budget change, with the aid of the data of geom’orphology, palynology, sedimentology and chronology, It is found that the climate experienced a warm and humid period during 7000-3500 yr. B. P. and showed a drying and warming trend in the last century in the Central Asia. 展开更多
关键词 climatic fluctuation INLAND LAKES lake EVOLUTION ARID zone
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The Quaternary faunas and climatic fluctuation in the tropical zone of China 被引量:1
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作者 HUANGZhenguo ZHANGWeiqiang 《Journal of Geographical Sciences》 SCIE CSCD 2003年第4期488-497,共10页
About 70 examples of Quaternary fauna in China's tropics are enumerated in this paper. Of which about 40% of the examples can be found even in cooling stages, showing the smaller amplitude of climatic fluctuation ... About 70 examples of Quaternary fauna in China's tropics are enumerated in this paper. Of which about 40% of the examples can be found even in cooling stages, showing the smaller amplitude of climatic fluctuation during Quaternary. According to the temporal and spatial distribution of tropical faunas, the following characters of climate variation can be evidenced: two main cycles in Early Pleistocene, three main cycles in Middle Pleistocene, two main cycles in Late Pleistocene and Holocene Megathermal. The drop in temperature during the Latest Glacial Period and Neoglaciation has not endangered the existence of tropical faunas. With influence of cooling fluctuation during historical period, some faunas have removed southwards progressively, but disappearance of these animals in China's tropics was mainly the result of artificial factors. 展开更多
关键词 FAUNAS climate China's tropics
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On the Possible Contribution of Natural Climatic Fluctuations to the Global Warming of the Last 135 Years 被引量:1
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作者 Maxim Ogurtsov Markus Lindholm Risto Jalkanen 《Atmospheric and Climate Sciences》 2017年第3期256-262,共7页
A number of numerical experiments with artificial random signals (the second order autoregressive processes), which have important statistical properties similar to that of the observed instrumental temperature (1850-... A number of numerical experiments with artificial random signals (the second order autoregressive processes), which have important statistical properties similar to that of the observed instrumental temperature (1850-2015), were carried out. The results show that in frame of the selected mathematical model the return period of climatic events, analogous to the current global warming (linear increase of temperature for 0.95°C during the last 135 years) is 2849-5180 years (one event per 2849-5180 years). This means that global warming (GW) of the last 135 years can unlikely be fully explained by inherent oscillations of the climatic system. It was found however, that natural fluctuations of climate may appreciably contribute to the GW. The return period of climatic episodes with 0.5°C warming during the 135 years (half of the observed GW) was less than 500 years. The result testifies that the role of external factors (emission of greenhouse gases, solar activity etc.) in the GW could be less than often presumed. 展开更多
关键词 Global WARMING climate NATURAL Oscillations
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THE STUDY ON CLIMATIC CHANGES AND LAKE LEVEL FLUCTUATIONS OF OINGHAIB LAKE IN HOLOCENE
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作者 陈发虎 潘保田 《Chinese Geographical Science》 SCIE CSCD 1993年第2期32-43,共12页
According to loess and palaeosol climatic record, field observation, analysis data and 14C dating, we discuss the climatic changes and the water level fluctuations of Qinghai Lake. It is pointed out that there were fo... According to loess and palaeosol climatic record, field observation, analysis data and 14C dating, we discuss the climatic changes and the water level fluctuations of Qinghai Lake. It is pointed out that there were four relatively warm and moist stages in Qinghai Lake basin during the Holocene. They formed in the periods from 10,300 yr.B.P. to 8,500 yr.B.P., 7,000 yr.B.P. to 3,500 yr.B.P., 2,800 yr.B.P. to 2,000 yr.B.P. and from 1,300 yr.B.P. up to now. The climate in the Holocene optimum period, from 7,000 yr.B.P. to 3,500 yr.B.P., was much warmer and moister than that today. Polypodium plant grew luxuriantly around Qinghai Lake. The annual temperature was 2.5℃ higher than that today, but there was no forest at Qinghai Lake shore. It is found that there was a good relationship between precipitation and water level fluctuation. In warm and moist period water level was high and in the cold and dry period it was low in the Holocene. There were four high water level periods for Qinghai Lake in the 展开更多
关键词 QINGHAI LAKE HOLOCENE LOESS section climatic changes water level fluctuationS
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QINGHAI LAKE FLUCTUATION AND CLIMATIC CHANGE SINCE THE LAST GLACIATION 被引量:1
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作者 王苏民 王云飞 +1 位作者 吴瑞金 李建仁 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1991年第2期170-183,共14页
Qinghai Lake is located in a hydrologically closed basin at the conjunction of SE and SW monsoons and westerlies . Its frequent lake level fluctuations arising from climatic and monsoonal changes have left a series of... Qinghai Lake is located in a hydrologically closed basin at the conjunction of SE and SW monsoons and westerlies . Its frequent lake level fluctuations arising from climatic and monsoonal changes have left a series of geological records since the last glaciation.The coarse sediments in Core QD1, the sporopollen assemblage representing steppe, the eolian paleo-sanddunes in the east and southeast banks and the fossil glacial topography all indicated frigid and arid climatic conditions and large scale shrinkage of the lake during the last glacial maximum. 展开更多
关键词 climatic GLACIAL SOUTHEAST records QINGHAI shrinkage representing ASSEMBLAGE FOSSIL frigid
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Climatic fluctuation and disasters during recent years in China's tropics 被引量:1
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作者 黄镇国 张伟强 《Journal of Geographical Sciences》 SCIE CSCD 2004年第z1期12-20,共9页
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Pulling Vs. Pushing:Effect of Climatic Factors on Periodical Fluctuation of Russian and South Korean Tourist Demand in Hainan Island,China 被引量:1
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作者 CHEN Fan LIU Jun GE Quansheng 《Chinese Geographical Science》 SCIE CSCD 2017年第4期648-659,共12页
While climate is an important factor attracting tourists to certain destinations,it can also motivate people residing in a country with a harsh climate to move to another location.By applying X-12 decompositions and a... While climate is an important factor attracting tourists to certain destinations,it can also motivate people residing in a country with a harsh climate to move to another location.By applying X-12 decompositions and a panel data regression analysis,this study analyzes the pull and push effects of climatic seasonal factors between destination(Hainan Island,China) and source countries(Russia and South Korea).The findings show that climatic seasonal factors have significant pulling and pushing effects on seasonal patterns of tourism demand,with temperature being the main factor.Furthermore,the number of paid vacation days in the source country affects that country's sensitivity to climatic seasonal factors;countries with a higher numbers of paid vacation days are more sensitive to climatic conditions.Lastly,future global warming may causes the aforementioned pull and push effects to abate,which will have an unavoidable influence on tourism industries. 展开更多
关键词 气候因素 旅游需求 海南岛 俄罗斯 周期性波动 韩国 中国 季节因素
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High-frequency climatic fluctuations over the past 30 ka in northwestern margin of the East Asian monsoon region, China
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作者 WU Huining CUI Qiaoyu 《Journal of Arid Land》 SCIE CSCD 2022年第12期1331-1343,共13页
Whether millennial-to centennial-scale climate variations throughout the Holocene convey universal climate change is still widely debated.In this study,we aimed to obtain a set of high-resolution multi-proxy data(1343... Whether millennial-to centennial-scale climate variations throughout the Holocene convey universal climate change is still widely debated.In this study,we aimed to obtain a set of high-resolution multi-proxy data(1343 particle size samples,893 total organic carbon samples,and 711 pollen samples)from an alluvial-lacustrine-aeolian sequence based on an improved age-depth model in the northwestern margin of the East Asian monsoon region to explore the dynamics of climate changes over the past 30 ka.Results revealed that the sequence not only documented the major climate events that corresponded well with those reported from the North Atlantic regions but also revealed many marked and high-frequency oscillations at the millennial-and centennial-scale.Specifically,the late stage of the last glacial lasting from 30.1 to 18.1 cal.ka BP was a dry and cold period.The deglacial(18.1-11.5 cal.ka BP)was a wetting(probably also warming)period,and three cold and dry excursions were found in the wetting trend,i.e.,the Oldest Dryas(18.1-15.8 cal.ka BP),the Older Dryas(14.6-13.7 cal.ka BP),and the Younger Dryas(12.5-11.5 cal.ka BP).The Holocene can be divided into three portions:the warmest and wettest early portion from 11.5 to 6.7 cal.ka BP,the dramatically cold and dry middle portion from 6.7 to 3.0 cal.ka BP,and the coldest and driest late portion since 3.0 cal.ka BP.Wavelet analysis results on the total pollen concentration revealed five substantially periodicities:c.5500,2200,900,380,and 210 a.With the exception of the c.5500 a quasi-cycle that was causally associated with the Atlantic meridional overturning circulation,the other four quasi-cycles(i.e.,c.2200,900,380,and 210 a)were found to be indirectly causally associated with solar activities.This study provides considerable insight into the dynamic mechanism of the Asian climate on a long-time scale and future climatic change. 展开更多
关键词 East Asian monsoon region total pollen concentrations climate periodicity millennial-centennial time scale Chinese Loess Plateau
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