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Research for length change of four seasons over China in recent 47 years 被引量:1
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作者 ZhenYan Yu GuangZhou Fan +3 位作者 Wei Hua DingWen Zhou Xin Lai YaXing Liu 《Research in Cold and Arid Regions》 2011年第6期517-525,共9页
Using daily temperature data from 599 Chinese weather stations during 1961-2007, the length change trends of four seasons dur- ing the past 47 years were analyzed. Results show that throughout the region, four seasons... Using daily temperature data from 599 Chinese weather stations during 1961-2007, the length change trends of four seasons dur- ing the past 47 years were analyzed. Results show that throughout the region, four seasons' lengths are: spring becomes shorter (-0.8 d/10yrs), summer becomes longer (3.2 d/10yrs), autumn (-0.5 d/10yrs) and winter (-1.6 d/10yrs) becomes shorter. This trend is different in spatial distribution, namely it is very obvious in northern than southern China, and also remarkable in eastern than western China. Summer change is most obvious, but autumn has little change comparatively. This trend is highly obvious in North, East, Central and South China. In the Southwest starting in the 21st century, summer becomes longer and winter shortens. The trend in the Plateau region since the 1980s is that spring becomes longer and winter shortens. The average annual temperature increased during the past 47 years, and the change of the average annual temperature precedes seasons' length. Thus, the average annual temperature has a certain influence on the length change of seasons. 展开更多
关键词 four seasons' length standard for season classification seasonal change global warming climate trend coefficient
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Effect of climate change on seasonal monsoon in Asia and its impact on the variability of monsoon rainfall in Southeast Asia 被引量:8
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作者 Yen Yi Loo Lawal Billa Ajit Singh 《Geoscience Frontiers》 SCIE CAS CSCD 2015年第6期817-823,共7页
Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate chang... Global warming and climate change is one of the most extensively researched and discussed topical issues affecting the environment.Although there are enough historical evidence to support the theory that climate change is a natural phenomenon,many research scientists are widely in agreement that the increase in temperature in the 20 th century is anthropologically related.The associated effects are the variability of rainfall and cyclonic patterns that are being observed globally.In Southeast Asia the link between global warming and the seasonal atmospheric flow during the monsoon seasons shows varying degree of fuzziness.This study investigates the impact of climate change on the seasonality of monsoon Asia and its effect on the variability of monsoon rainfall in Southeast Asia.The comparison of decadal variation of precipitation and temperature anomalies before the 1970 s found general increases which were mostly varying.But beyond the 1970 s,global precipitation anomalous showed increases that almost corresponded with increases in global temperature anomalies for the same period.There are frequent changes and a shift westward of the Indian summer monsoon.Although precipitation is observed to be 70%below normal levels,in some areas the topography affects the intensity of rainfall.These shifting phenomenon of other monsoon season in the region are impacting on the variability of rainfall and the onset of monsoons in Southeast Asia and is predicted to delay for 15 days the onset of the monsoon in the future.The variability of monsoon rainfall in the SEA region is observed to be decadal and the frequency and intensity of intermittent flooding of some areas during the monsoon season have serious consequences on the human,financial,infrastructure and food security of the region. 展开更多
关键词 Climate change Temperature anomalies Precipitation anomalies seasonal monsoons Rainfall variability Southeast Asia
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Seasonal changes in the number of Relict Gull (Larus relictus) at Ebinur Lake, Western China
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作者 Kedeerhan BAYAHEN 《Journal of Arid Land》 SCIE 2010年第2期151-155,共5页
The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter... The Relict Gull(Larus relictus) is recognized as a vulnerable species,with a worldwide population of about 6,000 individuals.Always inhabiting the extreme arid regions of Central Asia,their migratory routes and winter grounds are unclear.This research focused on distribution sites,habitat,behavior,population size and seasonal changes of Relict Gull.Line transects and point counts in every month were used to investigate the gulls around the Ebinur Lake.The result showed Relict Gull was summer visitor to Xinjiang,Western China.Population curve with a single peak was obtained.This gull appeared in early April and was 63 individuals(1% of the global population).The number remained stable from May to July in 2009.The discovery of fledglings indi-cates that Relict Gull may breed here.They left Ebinur Lake in August.Relict Gull in Ebinur Lake should belong to the Central Asian subpopulation,which was the most westerly record in China. 展开更多
关键词 Relict Gull(Larus relictus) POPULATION seasonal change Ebinur Lake Central Asia
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Seasonal changes in sperm parameters, testicular histology and circulating levels of reproductive hormones in the male African straw-colored fruit bat (Eidolon helvum)
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作者 Clifford N Abiaezute Chike F Oguejiofor +2 位作者 Innocent C Nwaogu Ikechukwu R Obidike Udensi M Igwebuike 《Asian pacific Journal of Reproduction》 2020年第4期197-203,共7页
Objective: To investigate seasonal changes in some reproductive characteristics of the male African straw-colored fruit bat [Eidolon (E.) helvum] in a tropical rain forest area of South-East Nigeria.Methods: Spermatoz... Objective: To investigate seasonal changes in some reproductive characteristics of the male African straw-colored fruit bat [Eidolon (E.) helvum] in a tropical rain forest area of South-East Nigeria.Methods: Spermatozoal characteristics in the testes and cauda epididymides, testicular histology, and the circulating levels of the reproductive hormones, testosterone, follicle stimulating hormone and luteinizing hormone were evaluated in male bats captured in late January (peak dry season), late May (early rainy season) and late September (late rainy season) of 2019. The bats were captured in Obiagu community in Enugu State, South-East Nigeria. Data were analyzed with analysis of variance. Results: There were high serum concentrations of testosterone in early and late rainy season and of luteinizing hormone in early rainy season, but the concentrations of both hormones were low during peak dry season. These hormonal changes corresponded with the testicular seminiferous and spermatogenic activities and testicular and epididymal sperm concentrations, which were also maximal during early and late rainy season but minimal during peak dry season. Epididymal sperm motility and vitality were also high in early and late rainy season but low in peak dry season, while sperm morphological abnormalities were low in early and late rainy season but elevated in peak dry season. There was histological evidence that spermatogenesis did not cease completely during testis regression, but continued at a reduced rate during the dry season. Conclusions: The findings do not support concurrent epididymal sperm storage with testis regression in E. helvum. Altogether, these indicate that seasonal changes significantly alter sperm characteristics, testicular histology and circulating levels of reproductive hormones in E. helvum within the study area. 展开更多
关键词 Eidolon helvum SPERMATOZOA Reproductive characteristics seasonal changes
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Structure and seasonal changes in atmospheric boundary layer on coast of the east Antarctic continent
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作者 BIAN Lingen ZOU Han +3 位作者 LIN Zhong ZHANG Dongqi Annette Rinke Klaus Dethloff 《Advances in Polar Science》 2013年第3期139-146,共8页
The temperature, humidity, and vertical distribution of ozone in the Antarctic atmospheric boundary layer(ABL) and their seasonal changes are analyzed, by using the high-resolution profile data obtained during the I... The temperature, humidity, and vertical distribution of ozone in the Antarctic atmospheric boundary layer(ABL) and their seasonal changes are analyzed, by using the high-resolution profile data obtained during the International Polar Year 2008 to 2009 at Zhongshan Station, to further the understanding of the structure and processes of the ABL. The results show that the fre- quency of the convective boundary layer in the warm season accounts for 84% of its annual occurrence frequency. The frequency of the stable boundary layer in the cold season accounts for 71% of its annual occurrence frequency. A neutral boundary layer ap- pears rarely. The average altitude of the convective boundary layer determined by the parcel method is 600 m; this is 200 to 300 m higher than that over inland Antarctica. The average altitude of the top of the boundary layer determined by the potential tempera- ture gradient and humidity gradient is 1 200 m in the warm season and 1 500 m in the cold season. The vertical structures of ozone and specific humidity in the ABL exhibit obvious seasonal changes. The specific humidity is very high with greater vertical gradi- ent in the warm season and very low with a lesser gradient in the cold season under 2 000 m. The atmospheric ozone in the ABL is consumed by photochemical processes in the warm season, which results in a slight difference in altitude. The sub-highest ozone center is located in the boundary layer, indicating that the ozone transferred from the stratosphere to the troposphere reaches the low boundary layer during October and November in Antarctica. 展开更多
关键词 coast of the east Antarctic continent structure of the atmospheric boundary layer OZONE seasonal changes
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Seasonal metal fluxes derived by the interaction of surface water and groundwater in an aquaculture estuary
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作者 Xiaoxiong Wang Jordi Garcia-Orellana +5 位作者 Xiaogang Chen Jianan Liu Fenfen Zhang Jianguo Qu Zhuoyi Zhu Jinzhou Du 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第8期113-124,共12页
Submarine groundwater discharge(SGD)plays a major role as a conveyor of metals to coastal waters.However,the seasonal change of metal fluxes derived through SGD is unclear.Here,we evaluated the behaviours and fluxes o... Submarine groundwater discharge(SGD)plays a major role as a conveyor of metals to coastal waters.However,the seasonal change of metal fluxes derived through SGD is unclear.Here,we evaluated the behaviours and fluxes of trace metals(Mn,Fe,Ba,Pb,U,Cr,Zn,Cu)in an estuary under different seasonal conditions.The behaviours of trace metals revealed that SGD was the source of Mn(3.51 mmol/(m^(2)·d)),Fe(0.174 mmol/(m^(2)·d))and Ba(0.024 mmol/(m^(2)·d)),but the Cu sink(−0.55μmol/(m^(2)·d))and other metals exhibited a seasonal source‒sink conversion.The seasonal variation of dissolved organic matter and the fresh groundwater proportion in subterranean estuaries may have an important effect on metals fluxes especially for the Fe,Mn and Ba.Our result shows that the single seasonal metal fluxes estimation applied to the annual scale will cause a large deviation,up to 3.6 times for Fe,5.5 times for Mn,and 15 times for Ba.Therefore,the influence of seasonal fluctuations on SGDderived metal fluxes cannot be ignored,and our findings will be important for comprehending the metal budget and cycle in nearshore environment. 展开更多
关键词 subterranean estuary seawater intrusion heavy metals seasonal changes coastal management
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Preliminary study on seasonal succession and development pathway of phytoplankton community in the Bohai Sea 被引量:25
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作者 Sun Jun, Liu Dongyan, Qian Shuben (1. Marine Ecosystem Dynamic Lab, Marine Life Science College, Ocean University of Qingdao, Qingdao 266003, China. ) 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2001年第2期251-260,共10页
Phytoplankton species composition and species succession were determined in 1998-1999 based on 2 nestle investigation cruises in the Bohai Sea and two monthly monitoring stations at Penglai and Changdao for 15 months... Phytoplankton species composition and species succession were determined in 1998-1999 based on 2 nestle investigation cruises in the Bohai Sea and two monthly monitoring stations at Penglai and Changdao for 15 months. The seasonal succession and pathway of phytoplankton community in the Bohai Sea were discussed complementarily with history data. The main process of Phytoplankton community development in the Bohai Sea was controlled by temperature and nutrient replenishes. There were two cell abundance peaks in an annual variation, the main peak in April and the secondary peak in September. In winter, the cell abundance was low due to the low temperature, the phytoplankton community was mainly made up of small-celled diataoms. In spring, the phytoplankton community was developed very quickly by small-celled diatom in suitable conditions of temperature and nutrients. In summer, the cell abundance decreased and big-celled diatoms became predominated. In autumn, because of the replenish of nutrient, big-celled diatoms and dinoflagellates formed another cell abundance peak. during the annual variation of phytoplankton community in the Bohai Sea, species succession was the main process of community development, the species sequence just occur at special areas and special periods. The evolution of phytoplankton community in the Bohai Sea accords with the hypothesis of Margalef's phytoplankton community of four stages. But the size feature is contrary to the hypothesis, which may be caused by nutrient replenish in autumn in Bohai Sea and the top to down control. 展开更多
关键词 Phytoplankton community seasonal changes species succession species sequence the Bohai Sea
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Simulation of Sea Ice in FGOALS-g2: Climatology and Late 20th Century Changes 被引量:3
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作者 徐世明 宋米荣 +12 位作者 刘骥平 王斌 李立娟 黄文誉 刘利 夏坤 薛巍 普业 董理 申思 胡宁 刘咪咪 孙文奇 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第3期658-673,共16页
Sea ice is an important component in the Earth's climate system. Coupled climate system models are indispensable tools for the study of sea ice, its internal processes, interaction with other components, and projecti... Sea ice is an important component in the Earth's climate system. Coupled climate system models are indispensable tools for the study of sea ice, its internal processes, interaction with other components, and projection of future changes. This paper evaluates the simulation of sea ice by the Flexible Global Ocean- Atmosphere-Land System model Grid-point Version 2 (FGOALS-g2), in the fifth phase of the Coupled Model Inter-comparison Project (CMIP5), with a focus on historical experiments and late 20th century simu:ation. Through analysis, we find that FGOALS-g2 produces reasonable Arctic and Antarctic sea ice climatology and variability. Sea ice spatial distribution and seasonal change characteristics are well captured. The decrease of Arctic sea ice extent in the late 20th century is reproduced in simulations, although the decrease trend is lower compared with observations. Simulated Antarctic sea ice shows a reasonable distribution and seasonal cycle with high accordance to the amplitude of winter-summer changes. Large improvement is achieved as compared with FGOALS-gl.0 in CMIP3. Diagnosis of atmospheric and oceanic forcing on sea ice reveals several shortcomings and major aspects to improve upon in the future: (I) ocean model improvements to remove the artificial island at the North Pole; (2) higher resolution of the atmosphere model for better simulation of important features such as, among others, the Icelandic Low and westerly wind over the Southern Ocean; and (3) ocean model improvements to accurately receive freshwater input from land, and higher resolution for resolving major water channels in the Canadian Arctic Archipelago. 展开更多
关键词 FGOALS-g2 CICE4-LASG sea ice seasonal change variability
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The sedimentary source, planform stability and shore normal morphological change of the Xichong beach on the southern coast of the Dapeng Peninsula of Shenzhen, Guangdong Province, China 被引量:2
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作者 ZHANG Song WANG Wei +1 位作者 HUANG Rihui XU Liubing 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第3期76-89,共14页
The coast of the Dapeng Peninsula has been honored as one of “the eight most beautiful coasts in China”. The most precious tourism resource for the peninsula is headland bay beaches, among which the beach at Xichong... The coast of the Dapeng Peninsula has been honored as one of “the eight most beautiful coasts in China”. The most precious tourism resource for the peninsula is headland bay beaches, among which the beach at Xichong on the southern coast of the peninsula is the longest and the most important one. The information of the stability, sedimentary source and shape change of the beach is very important for maintaining the beach in terms of sustainable development of the peninsula. Heavy minerals in the sand of the beach and the inland stream at Xichong are compared with those of a nearby beach on the same coast to determine the beach sand source; with help of a computer software, MEPBAY, the equilibrium planforms of the beaches on the peninsula are compared with those of an island without rivers to evaluate the stream's effects on the beach stability; cross shore profiles along the Xichong beach are also surveyed in different seasons of a year to assess the annual shore normal beach changes affected by the stream input, and the relation between the equilibrium planform state and cross shore changes of the beach. It is shown that (1) stream is the main sedimentary source of the beach and the weathering materials of the rocky headlands on both sides of the bay transported by waves are the second source for the beach but it is limited, sand from an inner shelf is not the sedimentary source for the beach at present and was not even during the Holocene transgression; (2) the Xichong beach cannot reach static equilibrium around the entire bay shoreline, the segment of the shore-line where a stream outlet is located is in dynamic equilibrium, and the unstable section occurs in the wave shadow region in the lee of an offshore island; (3) no matter whether the section of the beach shoreline at Xichong is in an equilibrium state or not, it is eroded in the typhoon season and recovered after the season, the maximum change in erosion and accretion occurs in the unstable segment; (4) the Xichong beach can only have small sand body since it is supplied with sand mainly form inland streams, resulting in a possible danger in which sand loss induced by human activities or huge storms cannot be replenished naturally. 展开更多
关键词 headland bay beach sedimentary source beach stability beach seasonal change Dapeng Peninsula
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Seasonal dynamics of soil water content in the typical vegetation and its response to precipitation in a semi-arid area of Chinese Loess Plateau 被引量:2
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作者 ZHOU Tairan HAN Chun +3 位作者 QIAO Linjie REN Chaojie WEN Tao ZHAO Changming 《Journal of Arid Land》 SCIE CSCD 2021年第10期1015-1025,共11页
Soil water content is a key limiting factor for vegetation growth in the semi-arid area of Chinese Loess Plateau and precipitation is the main source of soil water content in this area.To further understand the impact... Soil water content is a key limiting factor for vegetation growth in the semi-arid area of Chinese Loess Plateau and precipitation is the main source of soil water content in this area.To further understand the impact of vegetation types and environmental factors such as precipitation on soil water content,we continuously monitored the seasonal dynamics in soil water content in four plots(natural grassland,Caragana korshinskii,Armeniaca sibirica and Pinus tabulaeformis)in Chinese Loess Plateau.The results show that the amplitude of soil water content fluctuation decreases with an increase in soil depth,showing obvious seasonal variations.Soil water content of artificial vegetation was found to be significantly lower than that of natural grassland,and most precipitation events have difficulty replenishing soil water content below a depth of 40 cm.Spring and autumn are the key seasons for replenishment of soil water by precipitation.Changes in soil water content are affected by precipitation,vegetation types,soil evaporation and other factors.The interception effect of vegetation on precipitation and the demand for water consumption by transpiration are the key factors affecting the efficiency of soil water replenishment by precipitation in this area.Due to artificial vegetation plantation in this area,soil will face a water deficit crisis in the future. 展开更多
关键词 soil water content vegetation type PRECIPITATION seasonal change EVAPORATION
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Seasonal variation of foliar δ^(13)C values and its indictor significance in Sabina przewalskii and Sabina chinensis
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作者 Tuo Chen HuiJuan Pei +3 位作者 YouFu Zhang LongYing Wen HongGuan Tang YuanQing He 《Research in Cold and Arid Regions》 2011年第2期143-148,共6页
Seasonal variation of foliar δ13C values as well as proline, silicon, MDA and relative water content in Sabina przewalskii Kom. and S. chinensis (Lin.) Ant. were measured. The results show that foliar δ13C values ... Seasonal variation of foliar δ13C values as well as proline, silicon, MDA and relative water content in Sabina przewalskii Kom. and S. chinensis (Lin.) Ant. were measured. The results show that foliar δ13C values were significantly different at different seasons: lower in winter but higher in summer. δ13C values were positively correlated with air temperature and soil temperature. This demonstrates that foliar δ13C of Sabina is a successful empirical indictor of temperature. Furthermore, foliar δ13C values were positively related to proline and silicon content, and negatively related to relative water content and MDA content. Compared with S. chinensis, S. przewalskii has higher δ13C values, proline and silicon content as well as lower MDA and relative water content. All these results provided strong evidence that it is feasible for δ13C to be regarded as another index to evaluate freezing tolerance of Sabina. 展开更多
关键词 SABINA carbon isotope composition seasonal changes freezing tolerance
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Correlation analysis between the Aral Sea shrinkage and the Amu Darya River 被引量:1
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作者 WANG Min CHEN Xi +6 位作者 CAO Liangzhong KURBAN Alishir SHI Haiyang WU Nannan EZIZ Anwar YUAN Xiuliang Philippe DE MAEYER 《Journal of Arid Land》 SCIE CSCD 2023年第7期757-778,共22页
The shrinkage of the Aral Sea,which is closely related to the Amu Darya River,strongly affects the sustainability of the local natural ecosystem,agricultural production,and human well-being.In this study,we used the B... The shrinkage of the Aral Sea,which is closely related to the Amu Darya River,strongly affects the sustainability of the local natural ecosystem,agricultural production,and human well-being.In this study,we used the Bayesian Estimator of Abrupt change,Seasonal change,and Trend(BEAST)model to detect the historical change points in the variation of the Aral Sea and the Amu Darya River and analyse the causes of the Aral Sea shrinkage during the 1950–2016 period.Further,we applied multifractal detrend cross-correlation analysis(MF-DCCA)and quantitative analysis to investigate the responses of the Aral Sea to the runoff in the Amu Darya River,which is the main source of recharge to the Aral Sea.Our results showed that two significant trend change points in the water volume change of the Aral Sea occurred,in 1961 and 1974.Before 1961,the water volume in the Aral Sea was stable,after which it began to shrink,with a shrinkage rate fluctuating around 15.21 km3/a.After 1974,the water volume of the Aral Sea decreased substantially at a rate of up to 48.97 km3/a,which was the highest value recorded in this study.In addition,although the response of the Aral Sea's water volume to its recharge runoff demonstrated a complex non-linear relationship,the replenishment of the Aral Sea by the runoff in the lower reaches of the Amu Darya River was identified as the dominant factor affecting the Aral Sea shrinkage.Based on the scenario analyses,we concluded that it is possible to slow down the retreat of the Aral Sea and restore its ecosystem by increasing the efficiency of agricultural water use,decreasing agricultural water use in the middle and lower reaches,reducing ineffective evaporation from reservoirs and wetlands,and increasing the water coming from the lower reaches of the Amu Darya River to the 1961–1973 level.These measures would maintain and stabilise the water area and water volume of the Aral Sea in a state of ecological restoration.Therefore,this study focuses on how human consumption of recharge runoff affects the Aral Sea and provides scientific perspective on its ecological conservation and sustainable development. 展开更多
关键词 Aral Sea shrinkage recharge runoff Amu Darya River Syr Darya River multifractal detrend cross-correlation analysis(MF-DCCA) Bayesian Estimator of Abrupt change seasonal change and Trend(BEAST) Central Asia
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辽宁沙尘暴特点分析(英文) 被引量:2
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作者 黄阁 盛永 张宁娜 《Meteorological and Environmental Research》 CAS 2010年第11期76-79,84,共5页
Based on the factual data of dusty weather in Liaoning during the period from 1971 to 2009,the characteristics of dust storms were analyzed in the aspects including normality tests,inter-decadal variability,seasonal c... Based on the factual data of dusty weather in Liaoning during the period from 1971 to 2009,the characteristics of dust storms were analyzed in the aspects including normality tests,inter-decadal variability,seasonal changes and spatial distribution characteristics.The results showed that the sandstorm weather in Liaoning tended to occur less frequently with the significant inter-decadal variation.The sandstorm in Liaoning occurred frequently in spring(most frequently in April).The dusty weather mainly occurred in the northwest of Liaoning,Fuxin and the northern region of Chaoyang during the period from late March to early May. 展开更多
关键词 Dusty weather NORMALITY Inter-decadal variation seasonal changes Spatial distribution China
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Seasonal Changes in the Trade-off Among Fig-supported Wasps and Viable Seeds in Figs and Their Evolutionary Implications 被引量:12
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作者 Rui-WuWANG Jun-XingYANG Da-RongYANG 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2005年第2期144-152,共9页
Abstract: What the real trade-off is among fig-supported wasps and the viable seeds of figs is heatedly debated in the studies of fig/fig wasp mutualism. In the present study, we collected wasp offspring (galls) and t... Abstract: What the real trade-off is among fig-supported wasps and the viable seeds of figs is heatedly debated in the studies of fig/fig wasp mutualism. In the present study, we collected wasp offspring (galls) and the viable seeds of premature fruits, and determined the foundress number in receptive fruits and all the types of wasps supported by Ficus racemosa L. during both the rainy and dry seasons in Xishuangbanna, China. The data show that the galls were positively correlated with viable seeds (n= 32; r= 0.74; P < 0.001) when the proportion of vacant female flowers (PVFF) was high, in April (68.0%), and were negatively correlated with viable seeds (n= 48; r=?0.59; P < 0.05) when PVFF were limited (PVFF = 42.6%) during a colder month (January). The mean foundress number per fruit during the colder months is significantly lower than during the warmer months (F5, 603= 27.9; P < 0.001) and pollinator wasps can live longer during the colder months. During the colder months, the proportions of non-pollinators and wasp offspring are higher than those found during other months, whereas the proportion of viable seeds is not different compared with that of other months. Non-pollinator wasps tend to oviposit the female flowers that have been oviposited by pollinator wasps. The non-pollinators only negatively affect pollinator wasps and there is no obvious negative effect of non-pollinator wasps on viable seeds, so ovipositing by non-pollinator wasps will not result in the extinction of the figs during the process of evolution. The results of the present study indicate that figs can allow less foundresses to be in fruit cavities when PVFF are limited, which provides supporting evidence for the previous assumption that the plants have developed a mechanism to maintain a stable system because of the conflicts between the parties involved. 展开更多
关键词 Ficus racemosa L. MUTUALISM non-pollinator POLLINATOR seasonal change trade-off XISHUANGBANNA
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Estimation of net primary productivity in China using remote sensing data 被引量:10
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作者 SUN Rui, ZHU Qi-jiang (Dept. of Resources and Environment Sciences, Beijing Normal University, Beijing 100875, China) 《Journal of Geographical Sciences》 SCIE CSCD 2001年第1期14-23,共10页
It is significant to estimate terrestrial net primary productivity (NPP) accurately not only for global change research, but also for natural resources management to achieve sustainable development. Remote sensing dat... It is significant to estimate terrestrial net primary productivity (NPP) accurately not only for global change research, but also for natural resources management to achieve sustainable development. Remote sensing data can describe spatial distribution of plant resources better. So, in this paper an NPP model based on remote sensing data and climate data is developed. And 1km resolution AVHRR NDVI data are used to estimate the spatial distribution and seasonal change of NPP in China. The results show that NPP estimated using remote sensing data are more close to truth. Total annual NPP in China is 2.645X109 tC. The spatial distribution of NPP in China is mainly affected by precipitation and has the trend of decreasing from southeast to northwest. 展开更多
关键词 remote sensing net primary productivity VEGETATION MODEL seasonal change
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Photoperiod-and temperature-mediated control of the ethylene response and winter dormancy induction in Prunus mume 被引量:6
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作者 Ping Li Tangchun Zheng +6 位作者 Xiaokang Zhuo Man Zhang Xue Yong Lulu Li Jia Wang Tangren Cheng Qixiang Zhang 《Horticultural Plant Journal》 SCIE CSCD 2021年第3期232-242,共11页
Plant dormancy is essential for perennial plant survival.Different genotypes of Prunus mume,including Eumume group and Apricot Mei group,undergo leaf senescence and dormancy at different times.In order to verify the c... Plant dormancy is essential for perennial plant survival.Different genotypes of Prunus mume,including Eumume group and Apricot Mei group,undergo leaf senescence and dormancy at different times.In order to verify the cold resistance of P.mume,freeze resistance evaluation was carried out.Our results showed that Apricot Mei group had a stronger freezing tolerance than Eumume group and that leaf senescence and dormancy of Apricot Mei group occurred at an earlier period before winter.Based on phenotypic data in response to seasonal climate change,the significant candidate regions were selected using GWAS.Furthermore,through KEGG pathway and qRT-PCR analyses,we found that the ethylene-related genes,including PmEIL(Pm002057)and PmERF(Pm004265),were significantly upregulated in‘Songchun’Mei(Apricot Mei group)and downregulated in‘Zaohua Lve’Mei(Eumume group).Ethylene-related genes expression models showed that ethylene may be indirectly involved in the induction of dormancy.The PmEIL and PmERF genes were the core genes of the ethylene signal transduction pathway and were regulated by the exogenous ACC or PZA compounds.For non-dormant or weekly dormant perennial plants,application of ACC was able to induce plant dormancy and thus enhance cold/freeze tolerance.Overall,the expression of the major ethylene genes played a significant role in dormancy induction and freezing tolerance in P.mume;accordingly,application of ACC and PZA compounds were an effective approach for enhancing cold/freeze of tolerance of woody plant. 展开更多
关键词 Prunus mume seasonal climate change Ethylene-related genes Dormancy induction Freezing tolerance
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Hydrogeochemical characterization and quality assessment of groundwater using self-organizing maps in the Hangjinqi gasfield area,Ordos Basin,NW China 被引量:3
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作者 Chu Wu Chen Fang +2 位作者 Xiong Wu Ge Zhu Yuzhe Zhang 《Geoscience Frontiers》 SCIE CAS CSCD 2021年第2期781-790,共10页
Water resources are scarce in arid or semiarid areas,which not only limits economic development,but also threatens the survival of mankind.The local communities around the Hangjinqi gasfield depend on groundwater sour... Water resources are scarce in arid or semiarid areas,which not only limits economic development,but also threatens the survival of mankind.The local communities around the Hangjinqi gasfield depend on groundwater sources for water supply.A clear understanding of the groundwater hydrogeochemical characteristics and the groundwater quality and its seasonal cycle is invaluable and indispensable for groundwater protection and management.In this study,self-organizing maps were used in combination with the quantization and topographic errors and K-means clustering method to investigate groundwater chemistry datasets.The Piper and Gibbs diagrams and saturation index were systematically applied to investigate the hydrogeochemical characteristics of groundwater from both rainy and dry seasons.Further,the entropy-weighted theory was used to characterize groundwater quality and assess its seasonal variability and suitability for drinking purposes.Our hydrochemical groundwater dataset,consisting of 10 parameters measured during both dry and rainy seasons,was classified into 6 clusters,and the Piper diagram revealed three hydrochemical facies:Cl-Na type(clusters 1,2 and 3),mixed type(clusters 4 and 5),and HCO3-Ca type(cluster 6).The Gibbs diagram and saturation index suggested thatweathering of rock-forming mineralswere the primary process controlling groundwater chemical composition and validated the credibility and practicality of the clustering results.Two-thirds of 45 groundwater samples were categorized as excellent-or good-quality and were suitable as drinking water.Cluster changes within the same and different clusters from the dry season to the rainy season were detected in approximately 78%of the collected samples.The main factors affecting the groundwater quality were hydrogeochemical characteristics,and dry season groundwater quality was better than rainy season groundwater quality.Based on this work,such results can be used to investigate the seasonal variation of hydrogeochemical characteristics and assess water quality accurately in the others similar area. 展开更多
关键词 Self-organizing maps seasonal change Entropy-weighted theory Hydrogeochemical characteristics Groundwater quality
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The impact of the environmental factors on the photosynthetic activity of common pine (Pinus sylvestris) in spring and in autumn in the region of Eastern Siberia 被引量:3
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作者 N.E.Korotaeva M.V.Ivanova +1 位作者 G.G.Suvorova G.B.Borovskii 《Journal of Forestry Research》 SCIE CAS CSCD 2018年第6期1465-1473,共9页
The taiga coniferous forests of the Siberian region are the main carbon sinks in the forest ecosystems.Quantitatively, the size of the carbon accumulation is determined by the photosynthetic productivity, which is str... The taiga coniferous forests of the Siberian region are the main carbon sinks in the forest ecosystems.Quantitatively, the size of the carbon accumulation is determined by the photosynthetic productivity, which is strongly influenced by environmental factors. As a result,an assessment of the relationship between environmental factors and photosynthetic productivity makes it possible to calculate and even predict carbon sinks in coniferous forests at the regional level. However, at various stages of the vegetative period, the force of the connection between environmental conditions and the productivity of photosynthesis may change. In this research, correlations between the photosynthetic activity of Scots pine(Pinus sylvestris L.) with the environmental conditions were compared in spring and in autumn. In spring, close positive correlation of the maximum daily net photosynthesis was identified with only one environmental factor. For different years, correlations were for soil temperature(rs= 0.655,p = 0.00315) or available soil water supply(rs= 0.892,p = 0.0068). In autumn within different years, significant correlation was shown with two(temperature of air and soil; rs= 0.789 and 0.896, p = 0.00045 and 0.000006,respectively) and four factors: temperature of air(rs=0.749, p = 0.00129) and soil(rs= 0.84, p = 0.00000),available soil water supply(rs= 0.846, p = 0.00013) and irradiance(rs= 0.826, p = 0.000001). Photosynthetic activity has a weaker connection with changes in environmental factors in the spring, as compared to autumn.This is explained by the multidirectional influence of environmental conditions on photosynthesis in this period and by the necessity of earlier photosynthesis onset, despite the unfavorable conditions. This data may be useful for predicting the flow of carbon in dependence on environmental factors in this region in spring and in autumn. 展开更多
关键词 Pinus sylvestris L. Eastern Siberia CORRELATIONS Photosynthetic productivity seasonal changes in environment
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Impact of water and sediment discharges on subaqueous delta evolution in Yangtze Estuary from 1950 to 2010 被引量:2
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作者 Yun-ping YANG Yi-tian LI +1 位作者 Yong-yang FAN Jun-hong ZHANG 《Water Science and Engineering》 EI CAS CSCD 2014年第3期331-343,共13页
In order to determine how the subaqueous delta evolution depends on the water and sediment processes in the Yangtze Estuary, the amounts of water and sediment discharged into the estuary were studied. The results show... In order to determine how the subaqueous delta evolution depends on the water and sediment processes in the Yangtze Estuary, the amounts of water and sediment discharged into the estuary were studied. The results show that, during the period from 1950 to 2010, there was no significant change in the annual water discharge, and the multi-annual mean water discharge increased in dry seasons and decreased in flood seasons. However, the annual sediment discharge and the multi-annual mean sediment discharge in flood and dry seasons took on a decreasing trend, and the intra-annual distribution of water and sediment discharges tended to be uniform. The evolution process from deposition to erosion occurred at the -10 m and -20 m isobaths of the subaqueous delta. The enhanced annual water and sediment discharges had a silting-up effect on the delta, and the effect of sediment was greater than that of water. Based on data analysis, empirical curves were built to present the relationships between the water and sediment discharges over a year or in dry and flood seasons and the erosion/deposition rates in typical regions of the suhaqueous delta, whose evolution followed the pattern of silting in flood seasons and scouring in dry seasons. Notably, the Three Gorges Dam has changed the distribution processes of water and sediment discharges, and the dam's regulating and reserving functions can benefit the subaqueous delta deposition when the annual water and sediment discharges are not affected. 展开更多
关键词 water discharge sediment discharge seasonal change DELTA Yangtze Estuary
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The Effect of Weather Conditions on Pediatric Supracondylar Humerus Fractures 被引量:1
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作者 Şükrü Demir Sefa Key Murat Gürger 《Open Journal of Orthopedics》 2021年第10期308-314,共7页
<b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="... <b><span style="font-family:Verdana;">Background:</span></b><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> Environmental conditions are effective on childhood su</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">pracondylar humerus fractures. In this study</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">,</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> we evaluated the relationship between weather conditions and these fractures. </span><b><span style="font-family:Verdana;">Materials</span></b> <b><span style="font-family:Verdana;">and</span></b> <b><span style="font-family:Verdana;">Methods:</span></b><span style="font-family:Verdana;"> We started </span><span style="font-family:Verdana;">this study following the approval of a non-interventional research ethics</span><span style="font-family:Verdana;"> committee. Patients (<16 years) who applied to the hospital between January 2013 </span><span style="font-family:Verdana;">and July 2018 with supracondylar humerus fracture</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">s</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> were included in the</span></span></span><span><span><span style="font-family:;" "=""><span style="font-family:Verdana;"> study. The hospital’s PROBEL system was used to diagnose (International Classification of the Diseases, ICD, S42.4) radiological images and patient information. Information on the weather conditions in the day and time period, in </span><span style="font-family:Verdana;">which supracondylar humerus fracture occurred, was obtained from TR</span><span style="font-family:Verdana;"> (Turkey) Ministry of Agriculture and Forestry General Directorate of Mete</span><span style="font-family:Verdana;">orology. The relationship between supracondylar fracture and daily weather </span><span style="font-family:Verdana;">conditions (wind, air temperature, cloudiness, and</span><span style="font-family:Verdana;"> sea</span><span><span style="font-family:Verdana;">son) was analyzed. </span><b><span style="font-family:Verdana;">Results:</span></b><span style="font-family:Verdana;"> Most of the patients (n = 76, 40.6%, p < 0.05)</span></span><span style="font-family:Verdana;"> were fractures occurring under cloudless weather conditions. Fractures were con</span><span style="font-family:Verdana;">centrated with a second frequency in cloudy weather over 60%, except for</span><span style="font-family:Verdana;"> cloud</span><span style="font-family:Verdana;">less weather conditions (n = 51, 27.3%, p < 0.05). In the summer months </span><span style="font-family:Verdana;">when the air temperature was high, the number of fractures was higher (n = 62, 33.2%, p < 0.05) and less in the winter months (n = 24, 12.8%, p < 0.05). In hot weather conditions where the daily average temperature was above 20<span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;">&deg;</span>C, supracondylar humerus fractures were observed more (n = 101, 54%) and less than 10<span style="color:#111111;font-family:Roboto, sans-serif;font-size:16px;white-space:normal;background-color:#FFFFFF;">&deg;</span>C (n = 43, 23%, p < 0.05). Increased incidence of fractures was observed in the </span><span><span style="font-family:Verdana;">presence of wind (n = 4, 2.1%, p < 0.05). </span><b><span style="font-family:Verdana;">Conclusion:</span></b><span style="font-family:Verdana;"> Supracondylar</span></span><span style="font-family:Verdana;"> humerus fractures are </span><span style="font-family:Verdana;">common in children. Environmental conditions (temperature, wind, and</span><span style="font-family:Verdana;"> season) can be effective in the occurrence of these fractures.</span></span></span></span> 展开更多
关键词 Supracondylar Humerus Fracture seasonal change Weather Conditions Elbow Fractures
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