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春季变妆行动
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作者 蓓蓓 《流行色》 2006年第4期68-69,共2页
模特小档案姓名:毛丹年龄:24职业:市场督导爱好:音乐,旅游身高:167CM体形:修长向往形象:时尚,乖巧,个性模特诉求:毛丹是某化妆品公司市场督导,虽然从事时尚前沿的工作,也了解一些化妆技巧,但每次上妆后都不理想,以至对自己的形象失去信... 模特小档案姓名:毛丹年龄:24职业:市场督导爱好:音乐,旅游身高:167CM体形:修长向往形象:时尚,乖巧,个性模特诉求:毛丹是某化妆品公司市场督导,虽然从事时尚前沿的工作,也了解一些化妆技巧,但每次上妆后都不理想,以至对自己的形象失去信心,变得随大流,没有显著个性及风格。近日,她求助于e.y肘尚彩妆吧。 展开更多
关键词 造型 时尚 专业形象 个性 设计师 季变 眼部 行动 绿色 失去信心
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色彩流动旋律美 “四季”风物总宜人——影碟《四季变奏》鉴赏
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作者 音翔 《视听技术》 1994年第1期99-100,共2页
艺术都是相通的,这种相通不仅在于情感,而且在于感觉,所以宋人宋祁从满枝红杏感觉到了“春意闹”,唐代李贺在一段箜篌演奏中看到了“老鱼跳波瘦蛟舞”,韩愈更因听人弹琴而生出“冰炭置我肠”之感。心理学家、文艺批评家将这种现象称为... 艺术都是相通的,这种相通不仅在于情感,而且在于感觉,所以宋人宋祁从满枝红杏感觉到了“春意闹”,唐代李贺在一段箜篌演奏中看到了“老鱼跳波瘦蛟舞”,韩愈更因听人弹琴而生出“冰炭置我肠”之感。心理学家、文艺批评家将这种现象称为“联觉”,称为“通感”。 展开更多
关键词 旋律美 季变 小提琴协奏曲 现代主义 文艺批评家 视觉艺术 影碟 表现力 心理机制 合成器
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季节变化对木材贮存费用的影响
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作者 刘少义 朱文吉 《森林工程》 北大核心 2002年第2期1-2,共2页
本文通过对保管费用、木材菌虫侵害损失、资金滞留损失的季变分析 。
关键词 季变效应 保管费用 木材菌虫侵害损失 资金滞留损失 木材贮存费用
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Variation of East Asian Summer Monsoon and Its Relationship with Precipitation of China in Recent 111 Years 被引量:8
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作者 杨浩 智协飞 +1 位作者 高洁 刘樱 《Agricultural Science & Technology》 CAS 2011年第11期1711-1716,共6页
Based on the monthly average SLP data in the northern hemisphere from 1899 to 2009, East Asian summer monsoon intensity index in recent 111 years was calculated, and the interdecadal and interannual variation characte... Based on the monthly average SLP data in the northern hemisphere from 1899 to 2009, East Asian summer monsoon intensity index in recent 111 years was calculated, and the interdecadal and interannual variation characteristics of East Asian summer monsoon were analyzed. The results showed that East Asian summer monsoon in the 1920s was the strongest. The intensity of East Asian summer monsoon after the middle period of the 1980s presented weakened trend. It was the weakest in the early 21st century. Morlet wavelet analysis found that the interdecadal and interannual variations of East Asian summer monsoon had quasi-10-year and quasi-2-year significance periods. The interannual variation of precipitation in the east of China closely related to intensity variation of East Asian summer monsoon. In strong (weak) East Asian summer monsoon year, the rainfall in the middle and low reaches of Yangtze River was less (more) than that in common year, while the rainfall in North China was more (less) than that in common year. The weakening of East Asian summer monsoon was an important reason for that it was rainless (drought) in North China and rainy (flood) in the middle and low reaches of the Yangtze River after the middle period of the 1980s. 展开更多
关键词 East Asian summer monsoon VARIATION Precipitation of China
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Seasonal Changes in Photosynthetic Characteristics of Ammopiptanthus mongolicus 被引量:43
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作者 李文瑞 冯金朝 +2 位作者 江天然 张立新 刘新民 《Acta Botanica Sinica》 CSCD 1999年第2期190-193,共4页
Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductan... Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductance and stomatal limitation value tended to decline simultaneously, while the interoellularCO2 concentration was increased. According to the two criteria discriminating the stomatal limitation of Photosynthesis suggeSted by Fmrquhar and Sharkey, the seasonal changes in these parameters indicated that the decrease in Pn may not be due to stomatal factor. These studies proved that the relative contents of the large subunit of Rubisco and the photochemical activities correlated with the seasonal changes in the net photosyntheticrate, whieh may show that these two factors contribute primarily to the seasonal changeS in CO2 assimilation. 展开更多
关键词 Net photosynthetic rate Stomatal conductance Intercellular CO2 concentration Stomatal limitation value RUBISCO Electron transport activity
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Seasonal Dynamics of Terrestrial Net Primary Production in Response to Climate Changes in China 被引量:32
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作者 朴世龙 方精云 陈安平 《Acta Botanica Sinica》 CSCD 2003年第3期269-275,共7页
Study on seasonal responses of terrestrial net primary production (NPP) to climate changes is to help understand feedback between climate systems and terrestrial ecosystems and mechanisms of increased NPP in the north... Study on seasonal responses of terrestrial net primary production (NPP) to climate changes is to help understand feedback between climate systems and terrestrial ecosystems and mechanisms of increased NPP in the northern middle and high latitudes. In this study, time series dataset of normalized difference vegetation index (NDVI) and corresponding ground-based information on vegetation, climate, soil, and solar radiation, together with an ecological process model, were used to explore the seasonal trends of terrestrial NPP and their geographical differences in China from 1982 to 1999. As the results,. seasonal total NPP in China showed a significant increase for all four seasons (spring, summer, autumn and winter) during the past 18 years. The spring NPP indicated the largest increase rate, while the summer NPP was with the largest increase in magnitude. The response of NPP to climate changes varied with different vegetation types. The increased NPP was primarily led by an advanced growing season for broadleaf evergreen forest, needle-leaf evergreen forest, and needle-leaf deciduous forest, whilst that was mainly due to enhanced vegetation activity (amplitude of growth cycle) during growing season for broadleaf deciduous forest, broadleaf and needle-leaf mixed forest, broadleaf trees with groundcover, perennial grasslands, broadleaf shrubs with grasslands, tundra, desert, and cultivation. The regions with the largest increase in spring NPP appeared mainly in eastern China, while the areas with the largest increase in summer NPP occurred in most parts of Northwestern China, Qinghai-Xizang Plateau, Mts. Xiaoxinganling-Changbaishan, Sanjiang Plain, Songliao Plain, Sichuan Basin, Leizhou Peninsula, part of the middle and lower Yangtze River, and southeastern mountainous areas of China. In autumn, the largest NPP increase appeared in Yunnan Plateau-Eastern Xizang and the areas around Hulun Lake. Such different ways of the NPP responses depended on regional climate attributes and their changes. 展开更多
关键词 Carnegie-Ames-Stanford-Approach (CASA) model net primary production (NPP) seasonal change normalized difference vegetation index (NDVI) climate change
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Seasonal evolution of the Northern Yellow Sea cold water mass 被引量:2
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作者 李希彬 孙晓燕 +2 位作者 张秋丰 牛福新 姚志刚 《Marine Science Bulletin》 CAS 2013年第2期15-25,共11页
With the in-situ temperature and salinity observations taken seasonally in the Northern Yellow Sea area during the National 908 Water Investigation and Research Project from 2006 to 2007, the characteristics of the No... With the in-situ temperature and salinity observations taken seasonally in the Northern Yellow Sea area during the National 908 Water Investigation and Research Project from 2006 to 2007, the characteristics of the Northern Yellow Sea cold water mass (NYSCWM) were studied, including both its spatial pattern over the whole bottom and historically typical section from Dalian to Chengshantou. Seasonal evolution as well as its spatial distribution was analyzed to further understand the NYSCWM, as a result, some new features about the NYSCWM had been found. Compared to the previous studies, the center of colder water mass in summer moved eastward, but sharing the similar peak values for both temperature and salinity with historical data. In spring, the axis of 32.8 psu saltier moves westward approximately 75 km and the high salinity areas beyond 123.5° E were largely impaired comparing to that in winter. In winter, the NYSCWM almost disappeared due to the reinforced wind-induced mixing and the Yellow Sea Warm Currents (YSWC) moved northward and controlled most of the Northern Yellow Sea region. In autumn, two cold centers with the peak value of 9℃ were found inside the attenuated NYSCWM. 展开更多
关键词 the Northern Yellow Sea cold water mass seasonal evolution temperatureand salinity distribution Yellow Sea warm current
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Seasonal changes of soil respiration in Betula platyphylla forest in Changbai Mountain, China 被引量:2
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作者 刘颖 韩士杰 林鹿 《Journal of Forestry Research》 SCIE CAS CSCD 2009年第4期367-371,I0007,共6页
A stdudy was conducted to determine the seasonal changes of soil respiration and the contribution of root respiration to soil respiration in Betula plaophylla forest in Changbai Mountain from May to September in 2004.... A stdudy was conducted to determine the seasonal changes of soil respiration and the contribution of root respiration to soil respiration in Betula plaophylla forest in Changbai Mountain from May to September in 2004. Results indicated that the total soil respiration, root-severed soil respiration and the root respiration followed a similar seasonal trend, with a high rate in summer due to wet and high temperature and a low rate in spring and autumn due to lower temperature. The mean rates of total soil respiration, root-severed soil respiration and root respiration were 4.44, 2.30 and 2.14 μmol.m^-2.s^-1, respectively during the growing season, and they were all exponentially correlated with temperature. Soil respiration rate had a linear correlation with soil volumetric moisture. The Q10 values for total soil respiration, root-severed soil respiration and root respiration were 2,82, 2.59 and 3. 16, respectively. The contribution rate of root respiration to the total soil respiration was between 29.3% and 58.7% during the growing season, indicating that root is a major component of soil respiration. The annual mean rates of total soil respiration, root-severed soil respiration and root respiration were 1.96, 1.08, and 0.87 μmol.m^-2.s^-1, or 741.73 408.71, and 329.24 g.m^-2.a^-1, respectively. Root respiration contributed 44.4% to the annual total soil respiration. The relationship proposed for soil respiration with soil lemperature was useful for understanding and predicting potential changes in Changbai Mountain B. platyphylla forest ecosystem in response to forest management and climate change. 展开更多
关键词 root respiration seasonal variations soil respiration soil temperature soil water content
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Dissolved Inorganic Arsenic in the Yellow Sea and the East China Sea—Distributions and Seasonal Variations 被引量:2
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作者 任景玲 刘素美 张经 《Marine Science Bulletin》 CAS 2009年第1期24-36,共13页
The distributions and seasonal variations of total dissolved inorganic arsenic (TDIAs, [TDIAs] = [As^5+]+[As^3+]) and arsenite (As3.) in the Yellow Sea and East China Sea are presented hero based on the observa... The distributions and seasonal variations of total dissolved inorganic arsenic (TDIAs, [TDIAs] = [As^5+]+[As^3+]) and arsenite (As3.) in the Yellow Sea and East China Sea are presented hero based on the observations of 9 cruises carried out in 2000 - 2003. The study area covers a broad range of hydrographic and chemical properties. The emphasis is put on a southeast transect from Changjiang Estuary to the Ryukyu Islands (i.e. PN section) in the East China Sea to discuss the impact of terrestdal input on the marginal seas of China. Arsenic species (TDlAs and arsenite) are determined by selective hydride generation - atomic fluorescence spectrometry (HG-AFS). TDIAs concentrations were high in the coastal area of Changjiang Estuary and decreased slightly towards the shelf region. High concentratiOns of TDIAs were also existed in the near bottom layer of shelf edge of the East China Sea which indicated another source of arsenic from the incursion of Kuroshio Waters. The seasonal variations of TDIAs in the study area depend on the hydrographic stages of Changjiang and the incursion intensity of Kuroshio Waters. Arsenite showed opposite distributions with TDIAs, with higher concentrations appeared at the surface layer of shelf region, which was positive correlated with the chlorophyll a. Biological conversion of arsenate into arsenite was hypothesized for the observed distribution pattern and its seasonal variations. The stoichoimetric ratios of As to P were estimated to be about 2×10^3 at PN Section in summer. The concentrations of dissolved arsenic in the Yellow Sea and East China Sea were comparable with other areas in the world. 展开更多
关键词 dissolved arsenic SPECIES Yellow Sea and East China Sea distributions and seasonal variations
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Seasonal Changes in the Ultrastructure of the Vascular Cambium in Shoots of Populus tomentosa 被引量:1
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作者 殷亚方 姜笑梅 崔克明 《Acta Botanica Sinica》 CSCD 2002年第11期1268-1277,共10页
Wood is the product of cambial activity in trees, and the seasonal activity style of cambium directly influences wood biomass production, structures and properties. The seasonal changes in the ultrastructure of the va... Wood is the product of cambial activity in trees, and the seasonal activity style of cambium directly influences wood biomass production, structures and properties. The seasonal changes in the ultrastructure of the vascular cambium activity of Populus tonientosa Carr. planted in Beijing area were examined in shoot tissues collected during 15 months by means of transmission electron microscopy. Before xylem mother cells reactivated completely, the dividing fusiform cells in cambium and new phloem cells had appeared at the same time. The initiation of cambial activity may be related to the bud sprouting and the young leaf growth in shoots. More details about the ultrastructural changes of cambial cells at the onset of cambial activity have been gained. When the large vacuole in active cambial cells divided into smaller ones during the dormant phase, proteinaceous material that disappeared in active cambial cells refilled many of these small vactioles. In addition, lipid droplets and starch granules had the same cycles as proteinaceous material. The plasmalemma invaginations of fusiform cells were observed not only in active phase but also in dormancy. The endomembrane system consisting of nuclear membrane, endoplasmic reticulum (ER), dictyosomes and their secretory vesicles, changed in form and distribution at different phases during a cycle and performed important roles at the onset of active cambium and during the wall formation process of secondary xylem cells. The tangential walls remained relatively thin throughout the year but the radial walls thickened markedly when the cambium was dormant. During the transition from dormancy to activity, a partial autolysis occurred in the radial walls of the cambial cells, especially at the cell wall junctions. A notable feature of the cells at the onset of cambial activity was the thinning of the radial walls. 展开更多
关键词 vascular cambium ULTRASTRUCTURE endomembrane system cell wall seasonal changes Populus tomentosa
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Study on the Biological Diversity of Nematode-trapping Fungi in Erhai Lake 被引量:4
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作者 杨晓燕 刘立盘 +3 位作者 苏锡钧 叶远邦 黄爱英 苏鸿雁 《Agricultural Science & Technology》 CAS 2011年第8期1100-1102,共3页
[Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classificat... [Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classification and identification methods were used to isolate,purify and identify.[Result]3 genera and 22 species of nematode-trapping fungi were isolated.Arthrobotrys oligospora,A.musiformis and Dactylella leptospora were the dominant species,and their detection rates were 28.05%,16.04% and 8.92% respectively.By analyzing the diversity of nematode-trapping fungi in four seasons,it was found that the biological diversity was richer in summer,spring and autumn,and the diversity indexes were 2.59,2.47 and 2.34 respectively.The diversity index in winter was 1.48 and was lower.Species forming the adhesive nets were predominant;positive rate was 41.00%.[Conclusion]The rich nematode-trapping fungi resource existed in Erhai Lake,and its biological diversity had the seasonal variation characteristic.The nematode-trapping fungi which formed the viscous net were the dominant species in Erhai Lake. 展开更多
关键词 Erhai Lake Nematode-trapping fungi Biological diversity
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Effect of sea surface wind on the seasonal variation of sea level in the east of China seas
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作者 牟林 迟永祥 +4 位作者 刘首华 宋军 林霄沛 李琰 张建立 《Marine Science Bulletin》 CAS 2013年第2期26-36,共11页
Sea level seasonal variations in the east of China seas from 2004 to 2006 are simulated by the advanced ROMS model. The results show similar sea level spatial features with TOPEX/Poseidon observations, with annual ran... Sea level seasonal variations in the east of China seas from 2004 to 2006 are simulated by the advanced ROMS model. The results show similar sea level spatial features with TOPEX/Poseidon observations, with annual ranges decreasing gradually from the sea coast to the Kuroshio region. By getting rid of wind stress in ROMS model, the simulated sea level results still show obvious seasonal variations. However, the phenomenon of sea level anomaly disappears in Min Zhe Current Coastwise (MZCF) and Su Bei current coastwise (SBCF), and the change of it from coastal area to ocean recedes. The seal level difference between Bohai, Yellow Sea (BYS) and East China Sea (ECS) becomes weaker in spring and autumn. The annual differences decrease obviously, and the gradual change of annual ranges from seacoast to the Kuroshio almost disappears. The annual ranges in BYS are nearly identical. The annual range ratio without the wind stress to with the wind stress increases gradually from the sea coast to Kuroshio region. 展开更多
关键词 sea level seasonal variation numerical simulation sea surface wind
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Seasonal characteristics of Carex lasiocarpa biomass and nutrient accumulation in the typical wetland of Sanjiang Plain, China
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作者 王洋 刘景双 +1 位作者 窦晶鑫 赵光影 《Journal of Forestry Research》 SCIE CAS CSCD 2010年第3期389-393,400,共6页
Seasonal dynamics of above- and belowground biomass and nutrient characteristics (nitrogen, carbon, and phosphorus) of Carex lasiocarpa were investigated in the typical wetland of Sanjiang Plain, China from May 2007... Seasonal dynamics of above- and belowground biomass and nutrient characteristics (nitrogen, carbon, and phosphorus) of Carex lasiocarpa were investigated in the typical wetland of Sanjiang Plain, China from May 2007 to September 2008. The results show that the changes of aboveground biomass during the growing season are best described by the twice function curve model, whereas the changes of belowground biomass follow the exponential increase curve model. Both the organic carbon contents in the above- and belowground plant parts show significant positive linear correlations with the growing time, and the coefficients R2 are 0.983 and 0.746, respectively. The carbon accu-mulations of the above- and belowground plant parts during the growing season show the same dynamics as those of the biomass. However, the nitrogen contents and accumulation in C. lasiocarpa aboveground and belowground parts show exponential increase during the growing season. The dynamics of C. lasiocarpa phosphorus contents follows the twice function curve model, whereas the accumulation of phosphorus shows the linear increase. The ratios of C/N in different parts of C. lasiocarpa fit the negative linear relations with total nitrogen content in the growing season. Moreover, the ratios of C/P in C. lasiocarpa plant also fit the negative linear relations with total phosphorus content. The results show that nitrogen is the primary limiting nutrient for C. lasiocarpa growth as compared with carbon and phosphorus. 展开更多
关键词 Carex lasiocarpa nutrient accumulation the Sanjiang plain seasonal changes
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Preliminary Studies on Summer Precipitation Patterns in China 被引量:10
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作者 李鸾 《Agricultural Science & Technology》 CAS 2008年第1期150-156,共7页
[Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer preci... [Objective] Study on the spatial distribution of summer precipitation patterns and interannual and interdecadal variability. [Method] The summer precipitation patterns were obtained from standard field of summer precipitation data for 160 observation stations in China during 1951 -2000 by the utilization of empirical orthogonal function (EOF), and characteristics of interannual and interdecadal variability were analyzed. [Result] The summer precipitation mainly distributes in eastern part of China; The 1 st, 2nd and 3rd EOF modes of spatial distribution are especially remarkable as well consistent with the results of previous reports about three rainfall patterns from analysis on the percentages of precipitation anomaly of summer. [Conclusion] There exists interannual and interdecadal variability for summer precipitation in China. 展开更多
关键词 EOF method Summer precipitation patterns Spatial distribution Temporal distribution Interannual variability Interdecadal variability
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农民要学会打“时间差”
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作者 凌爱松 《福建农业》 1998年第9期29-29,共1页
农产品具有很强的季节性,在农产品集中上市期间由于竞争激烈,极易发生价低卖难而造成浪费,和农民减收的现象。而在淡季,农产品又缺贷断档,价格上涨,发生市民买难问题。由此卖难买难问题时常困扰着社会的经济生活,影响着人们的生活质量... 农产品具有很强的季节性,在农产品集中上市期间由于竞争激烈,极易发生价低卖难而造成浪费,和农民减收的现象。而在淡季,农产品又缺贷断档,价格上涨,发生市民买难问题。由此卖难买难问题时常困扰着社会的经济生活,影响着人们的生活质量和农民的生产效益。 因此农民要学会打“时间差”。它是解决农民卖难买难的一个重要措施。打好“时间差”要抓好三个环节: 展开更多
关键词 时间差 农民 卖难 农产品 菜篮子 反季节生产 生产效益 三个环节 季变 市民
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Analysis of Season Change in Jiyang from Meteorological Standpoint
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作者 刘树峰 苏轶 《Agricultural Science & Technology》 CAS 2012年第5期1073-1075,共3页
[Objective] The aim was to analyze changing characters of four seasons in Jiyang, providing references for farming and disaster prevention in the area. [Methed] Changing characters of initial time and lasting periods ... [Objective] The aim was to analyze changing characters of four seasons in Jiyang, providing references for farming and disaster prevention in the area. [Methed] Changing characters of initial time and lasting periods of four seasons in Jiyang for 30 years were analyzed from meteorological standpoint with weather information from 1981 to 2010 observed in surface meteorological observation in Jiyang. [Result] Recent 30 years, initial time of spring and winter in Jiyang were earlier than before, especially for spring. In contrast, initial time of summer and autumn were later, especially for autumn. In addition, periods of spring and winter declined and the latter changed more significantly. Meanwhile, periods of summer and autumn extended and rate of linear trend for summer period was 0.042 hou/year. [Conclusion] The research indicated that lasting days of summer extended significantly and of spring and winter shortened under the background of global warming. 展开更多
关键词 Four seasons Initial time Lasting period Changing trend
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Methane Emission from Natural Wetlands in China:Summary of Years 1995-2004 Studies 被引量:31
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作者 DING Wei-Xin CAI Zu-Cong 《Pedosphere》 SCIE CAS CSCD 2007年第4期475-486,共12页
From studies undertaken during 1995-2004, annual budgets of CH4 emissions from natural wetlands and its temporal and spatial variations were examined throughout China, and various factors influencing CH4 emissions wer... From studies undertaken during 1995-2004, annual budgets of CH4 emissions from natural wetlands and its temporal and spatial variations were examined throughout China, and various factors influencing CH4 emissions were also evaluated. The seasonal variation in CH4 emissions that increased with increasing plant growth reached its peak in August; decrease in the emissions was found in freshwater marshes but not in peatlands. Emissions were mainly controlled by temperature and depth of standing water. Low CH4 emissions at the early plant growing stages were not because of deficiency of organic C for CH4 production but because of low temperatures. Low temperatures not only reduced CH4 production but also stimulated CH4 oxidation by lowering the activity of other aerobic microbes which left more 02 in the rhizosphere for methanotrophs. Low summer temperatures (below 20 ℃) in the Qinghai-Tibetan Plateau lowered CH4 production and CH4 emission resulting in little or no seasonal variation of emissions. Diel and spatial variation in CH4 emissions depended on plant species. For plants that transport CH4 using the pressure-driven convective through-flow mechanism, diel variation in CH4 emissions was governed by diel variation of solar energy load (that produces temperature and vapor pressure differences within various plant tissues) and stomatal conductance. For plants that transport gases using the molecular diffusion mechanism only, the diel variation of CH4 emissions was because of differences in the magnitude of O2 produced through photosynthesis and then delivered into the rhizomes and/or rhizosphere for CH4 oxidation. Emergent plants could transport more CH4 than submerged plants because the former transport CH4 directly into the atmosphere rather than into water as do submerged plants where CH4 can be further be oxidized during its diffusion from water to the atmosphere. Emergent plants with high gas transport capacity could not only transport more CH4 into the atmosphere but also live in deeper water, which in turn would inundate more plant litter, resulting in increased availability of C for CH4 production. Annual CH4 emission from natural wetlands in China was estimated to be 1.76 Tg, up to 1.17 Tg of which was emitted from freshwater marshes. CH4 emission from freshwater marshes mainly occurred during the growing season and less than 8% was released during the freeze-thawing period despite the fact that thawing efficiently released CH4 fixed in ice column into the atmosphere. 展开更多
关键词 diel variation methane emission seasonal variation temporal variation WETLAND
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Effect of Management Practices on Seasonal Dynamics of Organic Carbon in Soils Under Bamboo Plantations 被引量:18
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作者 ZHOU Guo-Mo XU Jian-Ming JIANG Pei-Kun 《Pedosphere》 SCIE CAS CSCD 2006年第4期525-531,共7页
Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to qua... Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to quantify seasonal dynamics in SOC for bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) stands. The results with IM compared to CM showed large decreases in total organic carbon (TOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), and the MBC/TOC ratio in the soils. With all IM plots in the 0-20 cm depth across sampling periods, average decreases compared with CM were: TOC, 12.1%; MBC, 26.1%; WSOC, 29.3%; the MBC/TOC ratio, 16.1%; and the WSOC/TOC ratio, 20.0%. Due to seasonal changes of climate, seasonal variations were observed in MBC and WSOC. Soil MBC in the 0-20 cm depth in September compared to May were 122.9% greater for CM and 57.6% greater for IM. However, due primarily to soil temperature, soil MBC was higher during the July to November period, whereas because of soil moisture, WSOC was lower in July and January. This study revealed that intensive management in bamboo plantations depleted the soil C pool; therefore, soil quality with IM should be improved through application of organic manures. 展开更多
关键词 bamboo (Phyllostachys pubescens) conventional management DYNAMICS intensive management soil organic carbon
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Analysis of seasonal variation of water masses in East China Sea 被引量:13
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作者 齐继峰 尹宝树 +2 位作者 张启龙 杨德周 徐振华 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2014年第4期958-971,共14页
Seasonal variations of water masses in the East China Sea(ECS) and adjacent areas are investigated, based on historical data of temperature and salinity( T-S). Dynamic and thermodynamic mechanisms that affect seasonal... Seasonal variations of water masses in the East China Sea(ECS) and adjacent areas are investigated, based on historical data of temperature and salinity( T-S). Dynamic and thermodynamic mechanisms that affect seasonal variations of some dominant water masses are discussed, with reference to meteorological data. In the ECS above depth 600 m, there are eight water masses in summer but only five in winter. Among these, Kuroshio Surface Water(KSW), Kuroshio Intermediate Water(KIW), ECS Surface Water(ECSSW), Continental Coastal Water(CCW), and Yellow Sea Surface Water(YSSW) exist throughout the year. Kuroshio Subsurface Water(KSSW), ECS Deep Water(ECSDW), and Yellow Sea Bottom Water(YSBW) are all seasonal water masses, occurring from May through October. The CCW, ECSSW and KSW all have significant seasonal variations, both in their horizontal and vertical extents and their T-S properties. Wind stress, the Kuroshio and its branch currents, and coastal currents are dynamic factors for seasonal variation in spatial extent of the CCW, KSW, and ECSSW, whereas sea surface heat and freshwater fl uxes are thermodynamic factors for seasonal variations of T-S properties and thickness of these water masses. In addition, the CCW is affected by river runoff and ECSSW by the CCW and KSW. 展开更多
关键词 water masses seasonal variations KUROSHIO East China Sea
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Seasonal Changes in Food Uptake by the Sea Cucumber Apostichopus japonicus in a Farm Pond: Evidence from C and N Stable Isotopes 被引量:9
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作者 SUN Zhenlong GAO Qinfeng +2 位作者 DONG Shuanglin Paul K. S. Shin WANG Fang 《Journal of Ocean University of China》 SCIE CAS 2013年第1期160-168,共9页
This study investigated the seasonal changes in carbon (C) and nitrogen (N) stable isotope values of several typical food sources of Apostichopus japonicus in a farm pond, including particulate organic matter (POM), m... This study investigated the seasonal changes in carbon (C) and nitrogen (N) stable isotope values of several typical food sources of Apostichopus japonicus in a farm pond, including particulate organic matter (POM), macroalgae, benthic microalgae and animals such as nematode and copepod. The stable isotope technique was used to quantify relative contributions of various sources to the food uptake by A. japonicus. The results showed that significant changes occurred in the C and N stable isotope values of sea cucumber food sources due to the seasonality of micro-or macroalgae prosperity and the fluctuation of environmental conditions. The sea cucumber A. japonicus exhibited corresponding alterations in feeding strategy in response to the changes in food conditions. Calculation with a stable isotope mixing model showed that macroalgae was the principal food source for A. japonicus throughout the 1-yr investigation, with the relative contribution averaging 28.1% - 63.2%. The relative contributions of other food sources such as copepod and nematode, POM, benthic microalgae to the total food uptake by sea cucumber averaged 22.6% - 39.1%, 6.3% - 22.2%, 2.8% - 6.5%, and 2.8% - 4.2%, respectively. Together these results indicated that the seasonal changes in food sources led to the obvious temporal differences in the relative contribution of various food sources utilized by A. japonicus. Such findings provide the basic scientific information for improving the aquaculture techniques of A. japonicus, particularly for optimizing the food environment of A. japonicus culture in farm ponds. 展开更多
关键词 sea cucumber Apostichopus japonicus stable isotope feeding MACROALGAE
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