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Analysis of Temperature Trends and Variations in the Arabian Peninsula’s Upper Atmosphere
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作者 Abdullrahman H. Maghrabi 《Atmospheric and Climate Sciences》 2024年第1期85-100,共16页
In this study, the trends of upper-air temperatures are analysed by utilising radiosonde observations for the barometric levels at 700, 500, 300, 200, 150, 100 and 50 hPa from five meteorological stations within the A... In this study, the trends of upper-air temperatures are analysed by utilising radiosonde observations for the barometric levels at 700, 500, 300, 200, 150, 100 and 50 hPa from five meteorological stations within the Arabian Peninsula from January 1986 to August 2015. The mean monthly variations of the temperatures at these levels are characterised and established. The magnitudes of the annual trends of the mean temperatures for each site for the selected barometric levels are studied and statistically tested using Mann-Kendall rank statistics at different significance levels. The temperature trends at different pressure levels show that the upper troposphere and lower stratosphere are warming, while the middle troposphere is cooling which is consistent with the findings of other studies. The variations in upper air temperature observed in this study can be attributed to a range of factors, including increasing greenhouse gas concentrations, changes in atmospheric circulation patterns, variations in solar activity, aerosols and volcanic eruptions, and land use and land cover change. 展开更多
关键词 Upper-Air Temperature Variability Long-Term Trend Arabian Peninsula Climate Change Mann-Kendell
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A Concise Analysis of Semantic Changes in Address Terms——Taking“xiaoji?”and“tóngzhì”as Examples
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作者 陈菲菲 《海外英语》 2016年第12期186-187,190,共3页
Prevalent address terms are dynamic along the timeline of social development. Despite the newly-emerged forms like"meinü"and"shuaige", meanings of"xi?oji?"and"tóngzhì&... Prevalent address terms are dynamic along the timeline of social development. Despite the newly-emerged forms like"meinü"and"shuaige", meanings of"xi?oji?"and"tóngzhì"have also experienced a discursive history. And different meanings in different historical periods reflect changes in social life and the evolution of people's mind, or precisely, people's cognition. It gives a brief discussion of these semantic changes and probes tentatively some reasons both sociologically and cognitively. 展开更多
关键词 semantic changes ADDRESS TERM "xi?oji?" "tóngzhì" REASON
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A Lexical Comparative Analysis of the English and Chinese Color Terms in Connotation
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作者 WANG Bei 《Journalism and Mass Communication》 2014年第3期215-223,共9页
The vocabulary is the most active factor in the language, and the meaning of color words in the vocabulary is abundant. The nature is multicolored, so various nationalities have formed each unique color view in precip... The vocabulary is the most active factor in the language, and the meaning of color words in the vocabulary is abundant. The nature is multicolored, so various nationalities have formed each unique color view in precipitated long-term history, refracting gorgeous national culture. Culture has restrained the meaning of the color words from developing, and the cultural meaning of the color words has refracted out abundant cultural intension again. Because of different cultural issues, cultural tradition, and culture psychology, the cultural connotations of the English and Chinese color words differ greatly, as a result, these particular cultural connotation meanings are cast under different environments by different nationalities. There are a lot of similarities and differences on the meaning between English and Chinese color words. This paper analyzing Chinese and English color terms in the angle of lexicology, is guided by the book An Introduction to English Lexicology. After reviewing the research done by some linguists, this paper starts from the definition and origin of color terms, studies the changing and word-formation of color terms, then ends with some researches on the idioms on color terms, which gives a systematically comparison of Chinese and English color terms on their developing progress. 展开更多
关键词 color terms ORIGIN CHANGING WORD-FORMATION IDIOMS
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Influence of Lunar Activities on the Twenty-four Solar Terms
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作者 Cuixiang Zhong 《Journal of Earth Science and Engineering》 2021年第1期29-33,共5页
Twenty four solar terms is a knowledge system formed by the ancients through long-term observation of the annual activities of the sun.Although it roughly reveals the changing rules of seasons,climate and phenology in... Twenty four solar terms is a knowledge system formed by the ancients through long-term observation of the annual activities of the sun.Although it roughly reveals the changing rules of seasons,climate and phenology in a year,and reflects the influence of the sun on the earth’s climate change on a large scale,because the ancients ignored the influence of the moon’s activities on the earth’s climate change on a small scale,the 24 solar terms they summarized often can not accurately predict the earth's climate change.In order to make the 24 solar terms reflect not only the influence of the sun on the earth's climate change on a large scale,but also the influence of the moon's activities on the earth's climate change on a small scale,we must refer to the key time nodes of the moon's activities to divide the 24 solar terms.That is to say,the first day(the seventh or twenty second day of the lunar calendar)after the“Greater Cold”of the old year should be set as the“Beginning of Spring”of the new year,and then the day after half a month should be the next solar term,which is the first day of the moon’s next visit to the Antarctic or the Arctic,and so on.In this way,the 24 solar terms are consistent with the key nodes of lunar activities,and can accurately predict the changes of the earth's climate. 展开更多
关键词 Twenty-four solar terms lunar activity polar vortex global climate change
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Changes in Avian Spring Arrival Dates of 115 Species in the Central Appalachians over 127 Years
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作者 Lori Petrauski Sheldon Owen +1 位作者 George D. Constantz James T. Anderson 《American Journal of Climate Change》 2023年第4期527-547,共21页
Global climate change affects many facets of avian ecology, such as shifts in breeding phenology and migration patterns. Migrating bird species respond to changes in climate by shifting their temporal patterns of spri... Global climate change affects many facets of avian ecology, such as shifts in breeding phenology and migration patterns. Migrating bird species respond to changes in climate by shifting their temporal patterns of spring migration. However, variation in species’ responses exists based on various life history traits, which exposes some species to an increased risk of phenological mismatch. This study examined the spring arrival dates of 115 migrating species over 127 years (1889-2015) using archival sources in West Virginia, USA, making this research unique in the length of study, the high number of species studied, and the historical crowd-sourced observations analyzed. Of the 115 taxa, 45 showed significant negative slopes of spring arrival dates (arriving earlier in the spring) plotted against the year. In contrast, only nine species showed positive slopes (arriving later in the spring), albeit non-significant. The average advance of spring arrival date for all species was 1.7 days per decade, and an advance of 2.6 days per decade in species that showed significance. Arrival dates were associated with increasing spring temperatures—for each 1˚C increase, the arrival date advanced by 0.81 days/decade. Several life history traits were linked to species that advanced their first arrival dates, including a shorter distance migrated to reach wintering grounds, increasing populations, and foraging habitat. Most avian species are advancing their spring arrival dates in response to climate change. However, the implications of earlier spring arrival are unclear. We draw attention to shifts in arrival dates and wintering ranges, leading to a possible increase in overwintering in the mid-latitudes of North America. 展开更多
关键词 Avian Migration Climate Change Historical Migration Long-Term Dataset Migration Phenology Spring Arrival
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Causes of the Extreme Hot Midsummer in Central and South China during 2017:Role of the Western Tropical Pacific Warming 被引量:11
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作者 Ruidan CHEN Zhiping WEN +1 位作者 Riyu LU Chunzai WANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第5期465-478,共14页
This study investigates why an extreme hot midsummer occurred in Central and South China(CSC) during 2017. It is shown that the western North Pacific subtropical high(WNPSH) was abnormally intensified and westward-ext... This study investigates why an extreme hot midsummer occurred in Central and South China(CSC) during 2017. It is shown that the western North Pacific subtropical high(WNPSH) was abnormally intensified and westward-extending,resulting in anomalous high pressure and consequent extreme heat over CSC. The abnormal WNPSH was favored by the warming of the western tropical Pacific(WTP), which was unrelated to ENSO and manifested its own individual effect.The WTP warming enhanced the convection in-situ and led to anomalous high pressure over CSC via a local meridional circulation. The influence of the WTP was confirmed by CAM4 model experiments. A comparison between the 2017 midsummer and 2010 midsummer(with a stronger WNPSH but weaker extreme heat) indicated that the influence of the WNPSH on extreme heat can be modulated by the associated precipitation in the northwestern flank.The role of the WTP was verified by regression analyses on the interannual variation of the WTP sea surface temperature anomaly(SSTA). On the other hand, the WTP has undergone prominent warming during the past few decades, resulting from decadal to long-term changes and favoring extreme warm conditions. Through a mechanism similar to the interannual variation, the decadal to long-term changes have reinforced the influence of WTP warming on the temperature over CSC,contributing to the more frequent hot midsummers recently. It is estimated that more than 50% of the temperature anomaly over CSC in the 2017 midsummer was due to the WTP warming, and 40% was related to the decadal to long-term changes of the WTP SSTA. 展开更多
关键词 HOT MIDSUMMER CENTRAL and South China western tropical Pacific DECADAL to long-term changes
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Extreme Temperature Change of the Last 110 Years in Changchun,Northeast China 被引量:3
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作者 Xiujing YU Guoyu REN +4 位作者 Panfeng ZHANG Jingbiao HU Ning LIU Jianping LI Chenchen ZHANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2020年第4期347-358,I0002-I0006,共17页
In China and East Asia,the long-term continuous observational data at daily resolution are insufficient,and thus there is a lack of good understanding of the extreme climate variation over the last 100 years plus.In t... In China and East Asia,the long-term continuous observational data at daily resolution are insufficient,and thus there is a lack of good understanding of the extreme climate variation over the last 100 years plus.In this study,the extreme temperature indices defined by ETCCDI(Expert Team on Climate Change Detection and Indices)and local meteorological administrations were analyzed for Changchun City,Northeast China,by using the daily maximum temperature(Tmax)and daily minimum temperature(Tmin)over 1909?2018.The results showed that extreme cold events,such as cold days,cold nights,frost days,icing days,and low temperature days,decreased significantly at rates of?0.41 d(10 yr)^?1,?1.45 d(10 yr)^?1,?2.28 d(10 yr)^?1,?1.16 d(10 yr)?1 and?1.90 d(10 yr)^?1,respectively.Warm nights increased significantly at a rate of 1.71 d(10 yr)^?1,but warm days decreased slightly and the number of high temperature days decreased at a rate of?0.20 d(10 yr)?1.The frequency of cold surge events increased significantly at a rate of 0.25 d(10 yr)^?1,occurring mainly from the mid-1950s to late-1980s.The average Tmax,average Tmin and extreme Tmin increased at rates of 0.09℃(10 yr)^?1,0.36℃(10 yr)^?1 and 0.54℃(10 yr)^?1,respectively;and extreme Tmax decreased significantly at a rate of?0.17℃(10 yr)^?1.In 1909?2018,1951?2018 and 1979?2018,the indices related to cold events decreased,while the trends of the indices related to warm events were different for different periods. 展开更多
关键词 EXTREME temperature CLIMATE change LONG-TERM series observation Changchun NORtheAST China
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Climate change and permafrost stability in the eastern Canada Cordillera:The results of 33 years of measurements 被引量:3
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作者 Stuart A.Harris 《Research in Cold and Arid Regions》 2009年第5期381-403,共23页
Over the last 33 years,a network of climate stations has been set up at high altitude mountain permafrost sites from Plateau Mountain near Claresholm,Alberta,north to Sheldon Lake on the North Canol Road in the Yukon.... Over the last 33 years,a network of climate stations has been set up at high altitude mountain permafrost sites from Plateau Mountain near Claresholm,Alberta,north to Sheldon Lake on the North Canol Road in the Yukon.Taken together with the data from the US National Weather Service and the Canadian Atmospheric Environment Service,the results indicate a cooling of mean annual air temperature south of Calgary,no significant change in Calgary,a slight warming at Jasper,and a major warming at Summit Lake,west of Fort Nelson.In contrast,the south eastern and central Yukon show only a minor warming trend that lies well within the limits of a sixty-year record measured by the Canadian Atmospheric Environment Service.Along the Mackenzie valley and on the North Slope of Alaska,the mean annual air temperature is rising.Permafrost is aggrading on Plateau Mountain,degrading at Summit Lake,and appears to be stable in southern Yukon and southern Alaska.This is in contrast to the warming occurring on the Arctic coastal plain and along the Mackenzie valley.It therefore appears that changes in climate vary considera-bly from place to place,and even where warming may occur,it may not continue indefinitely.There has been a northward shift of the arctic front due to a weakening of air pressure in the Yukon and Alaska relative to the continental tropical(cT) and maritime polar(mT) air masses to the south.Any actual changes that may be occurring appear to undergo amplification along the Mackenzie valley and Arctic coastal plain and reduction by buffering in the interior Yukon and Alaskan mountains,a result of mi-cro-environmental factors.Continued,careful monitoring of the climate is required and needs to be expanded in the National Parks in the mountains in order to provide data on the changes that may be taking place.Such measurements can provide a sound basis for interpreting ecological and other climate-related data.The existing climate models are not working satisfactorily because we do not know enough about the causes and processes involved in climate change.Improved results can indicate where best to site structures such as pipelines so as to minimize maintenance costs.Models may also help explain why certain areas such as Beringia,which saw reduced climate change,acted as important refugia during the glaciations. 展开更多
关键词 PERMAFROST STABILITY long-term measurement climate change the Eastern Canada Cordillera
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THE JUMP OF CLIMATE CHANGE OF TYPHOON ACTIVITIES 被引量:1
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作者 陈兴芳 晁淑懿 《Journal of Tropical Meteorology》 SCIE 1997年第1期52-60,共9页
Based on data of typhoon over the West Pacific and the South China Sea for the last 40 years, theshort-term climate oscillation of typhoon activities was revealed. The result indicated that the climaticvariation of ty... Based on data of typhoon over the West Pacific and the South China Sea for the last 40 years, theshort-term climate oscillation of typhoon activities was revealed. The result indicated that the climaticvariation of typhoon activities has a tendency of climatic jump in changes in early 1970’s. It showed thatbefore the jump of change the number of typhoon was increased and the intensity of typhoon was intensified after which the tendency of variation went contrary. In addition, the increase of typhoon numberduring recent years suggested again the jump of climatic change in the late 1980’s, but the intensity oftyphoon did not have the same change. The analysis indicated that the short-term climatic oscillation andthe jump of climatic change have certain physical background. Such climate change tendency of typhoonwas shown to be related to the climatic oscillation of general circulation and SST, especially to the WestPacific subtropical high. 展开更多
关键词 TYPHOON SHORT-TERM CLIMATIC OSCILLATION JUMP of change
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Burial fluxes and sources of organic carbon in sediments of the central Yellow Sea mud area over the past 200 years 被引量:4
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作者 YANG Shu YANG Qian +3 位作者 LIU Sai CAI Deling QU Keming SUN Yao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2015年第10期13-22,共10页
Long-term changes of composition, sources and burial fluxes of TOC (total organic carbon) in sediments of the central Yellow Sea mud area and their possible affecting factors are discussed in this paper. Firstly, si... Long-term changes of composition, sources and burial fluxes of TOC (total organic carbon) in sediments of the central Yellow Sea mud area and their possible affecting factors are discussed in this paper. Firstly, similarity analysis is employed to confirm that the carbon burial features resulted from two collected cores are typical in the central Yellow Sea mud area where YSWC (Yellow Sea Warm Current) is prevalent. On this basis, the burial flux of TOC here was considered to be 235.5-488.4 pmol/(cm^2.a) since the first industrial revolution, accounting for about 70%-90% among burial fluxes of TC (total carbon) in the sediments. Compared TOC/TC ratio in the two cores with that in other marine sediments worldwide, we suggest that the growth of calcareous/non-calcareous organisms and dissolution of IC (inorganic carbon) are important factors controlling the TOC/TC ratio in sediment. Results of two-end mixed model based on fi13C data indicate that marine-derived organic carbon (OCa) is the main part among total burial organic carbon which accounts for a ratio over 85%. Due to the high TOC/TC ratio in the two cores, TC in the sediments also mainly exists as OCa, and the proportion of OCa is about 60%-80%. Away from the shore and relatively high primary production in upper waters are the main reasons that OCa is predominant among all burial OC in sediments of the central Yellow Sea mud area. Burial of OC in this mud area is probably mainly influenced by the human activities. Although the economic development during the late 19th century caused by the first industrial revolution in China did not obviously increase the TOC burial fluxes in the sediments, the rise of industry and agriculture after the founding of new China has clearly increased the TOC burial flux since 1950s. Otherwise, we also realize that among TC burial fluxes, TIC account for about 10%-30% in sediments of the central Yellow Sea mud area, so its burial could not be simply ignored here. Distinct from TOC burial, long-term TIC burial fluxes variations relate with climate changes more closely: the East Asian summer monsoon may influence the strength of the Huanghe River (Yellow River) flood, which could further affect the transport of terrestrial IC from land to the central Yellow Sea as well as the burial of these IC in the sediments. 展开更多
关键词 the central Yellow Sea mud area organic carbon burial flux source long-term changes human activities
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Study of Holocene glacier degradation in central Asia by isotopic methods for long-term forecast of climate changes
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作者 Vladimir I. Shatravin Tamara V. Tuzova 《Research in Cold and Arid Regions》 CSCD 2013年第1期114-125,共12页
This article presents a summary of our studies of Holocene moraines and glaciers of the Tien-Shan, Pamir, and Himalaya moun- mills with the purpose of providing pattern regularity of the Holocene glaciation decomposit... This article presents a summary of our studies of Holocene moraines and glaciers of the Tien-Shan, Pamir, and Himalaya moun- mills with the purpose of providing pattern regularity of the Holocene glaciation decomposition. We developed a method for ob- taining reliable radiocarbon dating of moraines with the use of autochthonous organic matter dispersed in fine-grained morainic material, as well there were shown new possibilities of isotope-oxygen and isotope-uranium analysis for the Holocene glaciations dynamics. We found that Holocene glaciations disintegrate stadiaUy according to the decaying principle, and seven main stages may be distinguished. We achieved the absolute dating of the first three stages, identifying these periods as 8,000, 5,000, and 3,400 years ago. The application of the above-mentioned isotope methods of the Holocene glaciations and moraines study will allow re- searchers to improve the offered model of the Holocene glaciations disintegration; it will be great contribution to salvation of the problem of long-term climatic and glaciations forecast. 展开更多
关键词 MORAINES GLACIATION HOLOCENE climate changes long-term forecast central Asia
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Multiple Solutions to the Problem of Kirchhoff Type Involving the Critical Caffareli-Kohn-Niremberg Exponent, Concave Term and Sign-Changing Weights
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作者 Mohammed El Mokhtar Ould El Mokhtar 《Applied Mathematics》 2017年第11期1703-1714,共12页
In this paper, we establish the existence of at least four distinct solutions to an Kirchhoff type problems involving the critical Caffareli-Kohn-Niremberg exponent, concave term and sign-changing weights, by using th... In this paper, we establish the existence of at least four distinct solutions to an Kirchhoff type problems involving the critical Caffareli-Kohn-Niremberg exponent, concave term and sign-changing weights, by using the Nehari manifold and mountain pass theorem. 展开更多
关键词 KIRCHHofF Type Problems Critical Caffareli-Kohn-Niremberg EXPONENT CONCAVE TERM Sign-Changing WEIGHTS
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Identifying Possible Climate Change Signals Using Meteorological Parameters in Short-Term Fire Weather Variability for Russian Boreal Forest in the Republic of Sakha (Yakutia)
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作者 Kiunnei Kirillina Wanglin Yan +1 位作者 Lynn Thiesmeyer Evgeny G. Shvetsov 《Open Journal of Forestry》 2020年第3期320-359,共40页
The Boreal forest is a terrestrial ecosystem highly vulnerable to the impacts of short-term climate and weather variabilities. Detecting abrupt, rapid climate-induced changes in fire weather and related changes in fir... The Boreal forest is a terrestrial ecosystem highly vulnerable to the impacts of short-term climate and weather variabilities. Detecting abrupt, rapid climate-induced changes in fire weather and related changes in fire seasonality can provide important insights to assessing impacts of climate change on forestry. This paper, taking the Sakha Republic of Russia as study area, aims to suggest an approach for detecting signals indicating climate-induced changes in fire weather to express recent fire weather variability by using short-term ranks of major meteorological parameters such as air temperature and atmospheric precipitation. Climate data from the “Global Summary of the Day Product” of NOAA (the United States National Oceanic and Atmospheric Administration) for 1996 to 2018 were used to investigate meteorological parameters that drive fire activity. The detection of the climate change signals is made through a 4-step analysis. First, we used descriptive statistics to grasp monthly, annual, seasonal and peak fire period characteristics of fire weather. Then we computed historical normals for WMO reference period, 1961-1990, and the most recent 30-year period for comparison with the current means. The variability of fire weather is analyzed using standard deviation, coefficient of variation, percentage departures from historical normals, percentage departures from the mean, and precipitation concentration index. Inconsistency and abrupt changes in the evolution of fire weather are assessed using homogeneity analysis whilst a Mann-Kendall test is used to detect significant trends in the time series. The results indicate a significant increase of temperature during spring and fall months, which extends the fire season and potentially contributes to increase of burned areas. We again detected a significant rainfall shortage in September which extended the fire season. Furthermore, this study suggests a new approach in statistical methods appropriate for the detection of climate change signals on fire weather variability using short-term climate ranks and evaluation of its impact on fire seasonality and activity. 展开更多
关键词 Boreal Forest Fires Climate Change Signal Short-Term Climate Variability Fire Weather Hydrometeorological Trends
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带有临界增长的Kirchhoff方程极小能量变号解的存在性 被引量:2
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作者 梁文国 黄永艳 《河北科技大学学报》 CAS 2020年第4期327-333,共7页
为了深入研究Kirchhoff方程的性质,讨论了带有Hartree项和临界增长非线性项的Kirchhoff方程极小能量变号解的存在性。利用能量泛函在变号Nehari流形上的下确界Cλ收敛于0,得到空间E紧嵌入L 6(R 3)这一技术性结果。结果表明,利用限制变... 为了深入研究Kirchhoff方程的性质,讨论了带有Hartree项和临界增长非线性项的Kirchhoff方程极小能量变号解的存在性。利用能量泛函在变号Nehari流形上的下确界Cλ收敛于0,得到空间E紧嵌入L 6(R 3)这一技术性结果。结果表明,利用限制变分方法和定量形变引理获得极小化序列对应的极小值点是该问题的非平凡解。研究方法在理论证明方面得到了良好的结果,对研究其他Kirchhoff方程解的存在性有一定的指导意义。 展开更多
关键词 非线性泛函分析 KIRCHHofF方程 Hartree非线性项 临界增长 变分方法 变号解
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Variations of Summer Phytoplankton Community Related to Environmental Factors in a Macro-Tidal Estuarine Embayment, Hangzhou Bay, China 被引量:6
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作者 ZHANG Yuexia YU Jun +2 位作者 JIANG Zhibing WANG Qin WANG Hui 《Journal of Ocean University of China》 SCIE CAS 2015年第6期1025-1033,共9页
To explore the distribution and composition of phytoplankton community and their responses to environmental changes, summer net-collected phytoplankton and physicochemical parameters in the Hangzhou Bay during 2004–2... To explore the distribution and composition of phytoplankton community and their responses to environmental changes, summer net-collected phytoplankton and physicochemical parameters in the Hangzhou Bay during 2004–2010 were investigated. A total of four phyla and 84 species were identified, including 67 diatom and 12 dinoflagellate species. The dominant species con- stantly consisted of the diatoms, although the dominance of dinoflagellate and cyanobacteria increased recently. Due to great spa- tio-temporal variations in environmental factors(salinity, suspended solids, and nutrient concentration), significant heterogeneities in community compositions among different years and subregions(inner and middle sections, and bay mouth) were found based on the analyses of multidimensional scaling and similarity. Canonical correspondence analysis showed that salinity and Si/N were the main variables associated with algal assemblage. Compared with the historical data since the 1980 s, eutrophication(N, P, and N/P increased with decreasing Si/N) was exacerbated drastically. Moreover, climatic forcing and human activities resulted in a series of physical alterations, including sediment retention, temperature increase, and salinity decrease as well as reduction in water exchanges. All these changes induced obvious increases in cell density and Chl-a while decreases in species diversity and diatom-dinoflagellate ratio as well as the shifting of dominant species. Therefore, the long-term phytoplankton variations were closely related to anthropogenic and climatic perturbations in the Hangzhou Bay. 展开更多
关键词 Hangzhou Bay PHYTOPLANKTON long-term changes EUTROPHICATION Qiantang River CHANGJIANG
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Establishment of ocean dumping area capacity assessment model
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作者 WANG Zhizu ZUO Juncheng +2 位作者 XU Ren JIN Zuowen CHEN Meixiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第1期106-113,共8页
Dumping area capacity is mainly affected by the hydrodynamic process (tidal sediment, storm surge and wave, etc.) as well as the size and depth of dumping area. Based on three-dimensional ocean circulation model kno... Dumping area capacity is mainly affected by the hydrodynamic process (tidal sediment, storm surge and wave, etc.) as well as the size and depth of dumping area. Based on three-dimensional ocean circulation model known as FVCOM (Finite Volume Coast and Ocean Model) and the stochastic dynamic statistical analysis model, taking advantage of dumping ground topography evolution and dumping quantity, the author aims to discuss the influence of hydrodynamic processes and dumping activity so as to built a new model of ocean dumping area capacity. With the data of depth and dumped amount in the dumping area, the changes of bottom topographic which caused by tidal current under the natural condition based on the FVCOM hydrodynamic and sediment module, the author strive to analyze the statistical relation of the changes for dumping amount, tidal current and bottom topographic. Through real data to fit revision coefficient values, which will be regarded as topographic changes reference value affected by wave and storm surges. Thus taking this evaluation as the long-term changes in the dumping capacity. In the premise of setting up the threshold of bottom topographic changes, the dumping area capacity is calculated. Take Yangtze Estuary No. 1 dumping area as an example, As the water depth reduces by 0.5 m annually, the dumping area capacity is about 6.7 million m3/a, the model results are in reasonable agreement with the actual amount. Then the model is validated in Luoyuan Bay dumping area, Shengsishangchuan Mountain dumping area, Dongding dumping area, Dongshan dumping area, and Wenzhou Port dumoin~ area. it is turns out the results are similar to that of the actual observations. 展开更多
关键词 capacity long term changes assessment model FVCOM
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The Changes in Guilin Paddy Soil Organic Matter and Rice Yield under Long-Term Fertilization 被引量:2
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作者 Qiuliang YU Zheng TANG +3 位作者 Zhongfang LI Chunlan CHEN Xiaoxian TANG Yanli LIN 《Asian Agricultural Research》 2016年第3期54-57,共4页
Rational fertilization is an important measure to increase crop yield and soil fertility. Through analysis,this paper aims to master the change characteristics of soil organic matter and rice yield under different fer... Rational fertilization is an important measure to increase crop yield and soil fertility. Through analysis,this paper aims to master the change characteristics of soil organic matter and rice yield under different fertilizer treatments,in order to provide an important reference for the sustainable use of soil and effective fertilization. Long-term( 19 years) rice crop rotation experiments in waterloggogenic paddy soil were conducted to investigate the change trend of crop grain yield and soil organic matter with time,reveal the dynamic characteristics and relationship between main fertility factors and crop yields using comparative analysis at three sites with conventional fertilization and non-fertilization in Guilin. The results showed that compared with previous years,the rice yield increased by 53% under the fertilization treatment and degreased by 66% under the control. Over the years,the average soil organic matter( SOM) content under fertilization treatment was 23% higher than under CK treatment. This indicates that chemical fertilizer and organic manure application can increase the rice yield and soil organic matter,and high rice yield can be attributed to the SOM increase. 展开更多
关键词 Long-term fertilization Waterloggogenic PADDY SOIL SOIL organic matter(SOM) Yield change
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Spatial / Temporal Features of Antarctic Climate Change
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作者 葛玲 梁佳兴 陈毅良 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1996年第3期375-382,共8页
Bused on January 1962-October 1993 mean value series of monthly mean temperature anomalies of 16 Antarctic stations on 10 standard isobanc surfaces from the surface to the 30 hPa,long term trends and periodic features... Bused on January 1962-October 1993 mean value series of monthly mean temperature anomalies of 16 Antarctic stations on 10 standard isobanc surfaces from the surface to the 30 hPa,long term trends and periodic features of climate changes from the troposphere to the lower stratosphere over the Antarctic region are investigated by maximum entropy power spectrum analysis,and the relation between climate change of the stratosphere (troposphere) and tolal ozone (southern 500 hPa circulation) is discussed. 展开更多
关键词 ANTARCTIC Climate change: Long term trend Periodicity Total ozone
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一类含凹项的分数阶Kirchhoff方程变号解的存在性和多重性
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作者 蔡序军 吴克晴 《长春师范大学学报》 2023年第10期12-22,54,共12页
研究了一类含凹项的分数阶Kirchhoff方程变号解的存在性和多重性,利用下降流不变集方法验证了变号解的存在性,借助属和相对属得到了变号解的多重性,并且确定了节点域数界.研究结果改进并推广了已知结果.
关键词 分数阶Kirchhoff方程 变号解 凹项 下降流不变集 属和相对属
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Long-term Changes in the Saline Lake Qarun(Egypt)
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作者 Gamal EL-SHABRAWY Mohamed GOHAR +2 位作者 Mousa GERMOUSH Elena ANUFRIIEVA Nickolai SHADRIN 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第S1期180-182,共3页
1 Introduction There is now ample evidence of the impacts of the recent climate change and anthropogenic activities on different saline lake ecosystems.All over the world salt lakes are threatened by climate change,wa... 1 Introduction There is now ample evidence of the impacts of the recent climate change and anthropogenic activities on different saline lake ecosystems.All over the world salt lakes are threatened by climate change,water diversions upstream for agricultural purposes,watershed changes,introduction of aliens,etc.that result in catastrophic 展开更多
关键词 saline lake long-term changes ZOOPLANKTON abiotic parameters.
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