共查询到20条相似文献，搜索用时 109 毫秒
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ＡＰＲＩＭＡＲＹＡＰＰＲＯＡＣＨＴＯＣＨＩＮＥＳＥＳＴＲＡＴＥＧＩＣＩＮＤＵＳＴＲＩＡＬＳＹＳＴＥＭ￥ＦａｎｇＣｈｕａｎｇｌｉｎ（ＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙ，ｔｈｅＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｂｅｉｊｉｎｇ１００１... 相似文献
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THE PRELIMINARY STUDY ON POSSIBLE SCENARIOS OF FLOOD AND DROUGHT IN CHINA IN THE CASE OF GLOBAL WARMING 总被引：1，自引：0，他引：1
ＴＨＥ ＰＲＥＬＩＭＩＮＡＲＹ ＳＴＵＤＹ ＯＮ ＰＯＳＳＩＢＬＥ ＳＣＥＮＡＲＩＯＳ ＯＦ ＦＬＯＯＤ ＡＮＤ ＤＲＯＵＧＨＴ ＩＮ ＣＨＩＮＡ ＩＮ ＴＨＥ ＣＡＳＥ ＯＦ ＧＬＯＢＡＬ ＷＡＲＭＩＮＧ ＣｈｅｎＪｉａｑｉ（陈家其）（Ｎａｎｊｉｎ... 相似文献
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ＰＲＥＬＩＭＩＮＡＲＹ ＳＴＵＤＹ ＯＮ ＴＨＥ ＨＯＬＯＣＥＮＥ ＥＮＶＩＲＯＮＭＥＮＴ ＣＨＡＮＧＥＳ ＩＮ ＸＩＮＪＩＡＮＧ──ＧＥＯＬＯＧＩＣ ＲＥＣＯＲＤＳ ＡＮＤ ＳＥＱＵＥＮＣＥ ＺｈｏｎｇＷｅｉ（钟巍）（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏ... 相似文献
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李玲 《中国地理科学(英文版)》1995,(2)
ＰＲＩＭＡＲＹＡＮＡＬＹＳＩＳＯＮＷＯＭＥＮ＇ＳＳＴＡＴＵＳＯＦＲＥＮＨＥＴＯＷＮ，ＢＡＩＹＵＮＤＩＳＴＲＩＣＴ，ＧＵＡＮＧＺＨＯＵ￥ＬｉＬｉｎｇ（李玲）（ＣｅｎｔｒｅｆｏｒＵｒｂａｎ＆ＲｅｇｉｏｎａｌＳｔｕｄｉｅｓ．ＺｈｏｎｇｓｈａｎＵｎｉｖｅｒｓ... 相似文献
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１ ＡＤＶＡＮＣＩＮＧＯＦＴＨＥＱＵＥＳＴＩＯＮＡＮＤＣＯＮＳＴＲＵＣＴＩＯＮＢＡＣＫＧＲＯＵＮＤＯＦＳＵＺＨＯＵＩＮＤＵＳＴＲＹＧＡＲＤＥＮＰｅｒｒｏｘｇａｖｅｓｐｅｃｉａｌａｔｔｅｎｔｉｏｎｔｏｔｈｅｅｆｆｅｃｔｏｆｉｍｐｏｒｔａｎｔｉｔｅｍｓａｎｄｃｏｎｓｔｒｕｃｔｉｏｎｏｆｉｎｆｒａｓｔｒｕｃｔｕｒｅｗｈｅｎｈｅｄｉｓｃｕｓｓｅｄｔｈｅｐｒｏｄｕｃｔｉｏｎｏｆｇｒｏｗｔｈｐｏｌｅ（Ｌｉ,１９８８）．Ｌｏｔｓｏｆｄｏｍｅｓｔｉｃｓｃｈｏｌａｒｓｈａｖｅａｌｓｏｐｒｏｂｅｄｉｎｔｏｔｈｉ… 相似文献
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GLACIER MELTWATER RUNOFF IN CHINA AND ITS NOURISHMENT TO RIVER 总被引：3，自引：0，他引：3
杨针娘 《中国地理科学(英文版)》1995,5(1):66-76
ＧＬＡＣＩＥＲＭＥＬＴＷＡＴＥＲＲＵＮＯＦＦＩＮＣＨＩＮＡＡＮＤＩＴＳＮＯＵＲＩＳＨＭＥＮＴＴＯＲＩＶＥＲ￥ＹａｎｇＺｈｅｎｎｉａｎｇ（杨针娘）（ＬａｎｚｈｏｕＩｎｓｔｉｔｕｔｅｏｆＧｌａｃｉｏｌｏｇｙａｎｄＧｅｏｃｒｙｏｌｏｇｙ，ｔｈｅＣｈｉｎｅｓ... 相似文献
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ＦＡＣＴＯＲＳ ＡＦＦＥＣＴＩＮＧ ＦＯＲＭＡＴＩＯＮ ＡＮＤ ＤＥＶＥＬＯＰＭＥＮＴ ＯＦ ＴＨＥ ＵＲＢＡＮ ＩＮＤＵＳＴＲＩＡＬ ＤＩＳＴＲＩＣＴ ＩＮ ＣＨＩＮＡ──Ａ Ｃａｓｅ ＳｔｕｄｙｏｎＣａｏｈｅｊｉｎｇＨｉ－ＴｅｃｈＰａｒｋｉｎＳｈ... 相似文献
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ＡＬＯＣＡＴＩＯＮＡＬＣＯＭＰＡＲＡＴＩＶＥＳＴＵＤＹＯＮＨＩＧＨ－ＴＥＣＨＩＮＤＵＳＴＲＩＡＬＺＯＮＥＳＩＮＣＨＩＮＡＷｅｉＸｉｎｚｈｅｎ魏心镇；ＳｈｉＹｏｎｇｈｕｉ史永辉（ＤｅｐａｒｔｍｅｎｔｏｆＧｅｏｇｒａｐｈｙ．ＰｅｋｉｎｇＵｎｉｖｅｒｓｉｔ... 相似文献
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Luo Chengde 《中国地理科学(英文版)》1997,8(1):91-95
Mt.Ma’an (4288 m) is the highest mountain in the southwest edge of Sichuan Basin. It is situated to the south of the Dadu
River. The geographic coordinates are: 28°58′N, 102°55′E. There are six peaks over 4000 m in elevation. Many quaternary glacial
landforms in this mountain have been discovered. It’s a typical example of fossil glacial landform in the east China. Its
glacial stages are the last glaciation (Q
3
3
) and the neoglaciation (Q
4
3
). Mt. Ma’an and Mt. Luoji (4359 m) are similar in the fossil glacial landforms, but there are still some differences between
them. For example, the ratio between the direct difference and the minus difference is different. 相似文献
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Eutrophication, which is the enrichment of a water mass with inorganic and organic nutrients that support plant growth, is a key factor in stimulating phytoplankton growth. In this study, we determined the effects of various nitrogen sources, different nitrogen concentrations in the culture medium, and two culture methods on the growth of the green alga, Enteromorpha prolifera. The relationship between the specific growth rate of E. prolifera and NO3--N concentration was consistent with that estimated using the Monod equation (R2 = 0.9713, P < 0.01). In the NO3--N medium, the maximum specific growth rate was calculated to be 0.1634/d and the semi-saturation constant was calculated to be 16.86 μmol/L. Our results show that E. prolifera can effectively utilize NH4+-N, NO3--N, and NO2--N and urea-N in the range of 5 to 50 μmol/L. NH4+-N was preferentially assimilated by E. prolifera, and urea-N was favorable for long-term growth. 相似文献
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Flume simulation of wave-induced release of internal dissolved nitrogen in Taihu Lake, China 总被引：1，自引：0，他引：1
A wave flume simulator was used to study internal nitrogen release from the surface sediment collected from Taihu Lake,China.Particulate nitrogen concentrations were positively correlated with the concentrations of suspended solids,primarily from surface erosion related to the shear stress and duration of wave action.In response to 4 cm-and 10 cm-high wave production representing waves generated in Taihu Lake by gentle and gusty winds,respectively,the mean dynamic release rate of ammonium(NH+4) from the sediment to the overlying water was 1×10-3 mg/(m2.s) and the NH4+ concentration in the overlying water increased by 0.016 mg/L,indicating that waves resulting from strong wind can induce the rapid release of dissolved nitrogen from Taihu Lake sediments.The decrease in interstitial NH+4 concentrations at all sediment depths was associated with an increase in NH4+ concentrations in the overlying water by 0.01 mg/L,showing that sediment below the eroded layer was the main source of internal nitrogen release.Changes in the interstitial dissolved oxygen and NH+4 concentrations showed that wave-induced pore water movement can greatly increase the diffusion rate,and that these effects can influence the sediment to a depth of at least 15 cm.Diffusion induced by pore water movement may be very important for the formation of an active sediment layer in Taihu Lake. 相似文献
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The aim of this study was to investigate the effects of light intensity and enhanced nitrogen supply on the growth and photosynthesis of the green-tide macroalga, Ulva prolifera. Thalli of U. prolifera were grown in natural or NH 4 +-enriched seawater under two different light intensities for 7 days, and then the growth rate, pigmentation, and photosynthetic performance of the thalli were evaluated. The results show that the relative growth rate(RGR) was markedly higher under the high light level than under the low light level. Enrichment with NH 4 + enhanced the RGR under high light intensity, but did not affect RGR under low light intensity. In low light conditions, NH 4 +-enrichment resulted in a marked decrease in the maximal photosynthetic rate( P m) and the maximum carbon fixation rate( V max), but it did not affect the half saturation constant for carbon( K 0.5) or the ratio of V max to K 0.5, which reflects the carbon acquisition efficiency. In high light conditions, P m, K 0.5, and the dark respiration rate( R d) increased under NH 4 + enrichment, but V max and the V max / K 0.5 ratio decreased. Regardless of the light intensity, NH 4 +-enrichment did not affect the apparent photosynthetic efficiency( α), which refl ects the ability of the alga to use light energy at low light levels. Under both low and high light intensities, the chlorophyll a(Chl a), chlorophyll b(Chl b), and carotenoids(Car) contents in thalli were higher in NH 4 +-enriched than in natural seawater, except that there was a decrease in the Chl b content of thalli in NH 4 +-enriched seawater under low light intensity. Therefore, NH 4 + enrichment improved the growth and photosynthetic performance of U. prolifera under high light intensity, but not under low light intensity. We discuss the possible mechanisms underlying these physiological responses. 相似文献
15.
Lei Xing Yiqing Jiang Zineng Yuan Hailong Zhang Li Li Liping Zhou Meixun Zhao 《中国海洋大学学报(英文版)》2013,12(4):599-604
As an important marginal sea under the influences of both the Changjiang River and the Kuroshio, the East China Sea (ECS) environment is sensitive to both continental and oceanic forcing. Paleoenvironmental records are essential for understanding the long-term environmental evolution of the ECS and adjacent areas. However, paleo-temperature records from the ECS shelf are currently very limited. In this study, the U 37 K′ and TEX86 paleothermometers were used to reconstruct surface and subsurface temperature changes of the mud area southwest of the Cheju Island (Site F10B) in the ECS during the Holocene. The results indicate that temperature changes of F10B during the early Holocene (11.6–6.2 kyr) are associated with global climate change. During the period of 6.2–2.5 kyr, the similar variability trends of smoothing average of ΔT (the difference between surface and subsurface temperature) of Site F10B and the strength of the Kuroshio suggest that the Kuroshio influence on the site started around 6.2 kyr when the Kuroshio entered the Yellow Sea and continued to 2.5 kyr. During the late Holocene (2.5–1.45 kyr), apparent decreases of U 37 K′ sea surface temperature (SST) and ΔT imply that the direct influence of the Kuroshio was reduced while cold eddy induced by the Kuroshio gradually controlled hydrological conditions of this region around 2.5 kyr. 相似文献
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The de-eutrophication abilities and characteristics of Ulva pertusa, a marine green alga, were investigated in Qingdao Yihai Hatchery Center from spring to summer in 2005 by analyzing the dynamic changes in NH 4 + , NO 3 ? , NO 2 ? as well as the total dissolved inorganic nitrogen (DIN). The results show that the effluent wastewater produced by fish aquaculture had typical eutrophication levels with an average of 34.3 μmol L?1 DIN. This level far exceeded the level IV quality of the national seawater standard and could easily lead to phytoplankton blooms in nature if discarded with no treatment. The de-eutrophication abilities of U. pertusa varied greatly and depended mainly on the original eutrophic level the U. pertusa material was derived from. U. pertusa used to living in low DIN conditions had poor DIN removal abilities, while materials cultured in DIN-enriched seawater showed strong de-eutrophication abilities. In other words, the de-eutrophication ability of U. pertusa was evidently induced by high DIN levels. The de-eutrophication capacity of U. pertusa seemed to also be light dependent, because it was weaker in darkness than under illumination. However, no further improvement in the de-eutrophication capacity of U. pertusa was observed once the light intensity exceeded 300 μmol M2 S?1. Results of semi-continuous wastewater replacement experiments showed that U. pertusa permanently absorbed nutrients from eutrophicated wastewater at a mean rate of 299 mg/kg fresh weight per day (126 mg/kg DIN during the night, 173 mg/kg in daytime). Based on the above results, engineered de-eutrophication of wastewater by using a U. pertusa filter system seems feasible. The algal quantity required to purify all the eutrophicated outflow wastewater from the Qingdao Yihai Hatchery Center into oligotrophic level I clean seawater was also estimated using the daily discharged wastewater, the average DIN concentration released and the de-eutrophication capacity of U. pertusa. 相似文献
17.
Seasonal succession of phytoplankton in response to the variation of environmental factors in the Gaolan River, Three Gorges Reservoir, China 总被引：1，自引：0，他引：1
To understand the responses of a freshwater ecosystem to the impoundment of the Three Gorges Reservoir (TGR), phytoplankton was monitored in the tributaries of the TGR area. From August 2010 to July 2011, algal species composition, abundance, chlorophyll a and other environmental parameters were investigated in the Gaolan River, which is a tributary of Xiangxi River. Thirty-one algal genera from seven phyla were identified. Results show that the lowest concentrations of total phosphorus (TP) and total nitrogen (TN) were 0.06 mg/L and 1.08 mg/L, respectively. The values of TP and TN exceeded the threshold concentration of the eutrophic state suggested for freshwater bodies. In the Gaolan River, the succession of phytoplankton showed clear seasonal characteristics. Different dominant species were observed among seasons under the control of environment factors. In spring and summer, the dominant species were Nitzschia sp. and Aphanizomenon flos-aquae (L.) Ralfs, the limiting nutrient was NO 3 ? -N, and the key environmental factor for phytoplankton population succession was water temperature (WT). In autumn and winter, the dominant species were A. flos-aquae and Chlorella sp., the limiting nutrient was PO 4 3? -P, and the key environmental factors were transparency and WT. This study illustrates the influence of physical and chemical factors on phytoplankton seasonal succession in a tributary of TGR since the downstream regions of Xiangxi River and Gaolan River became reservoirs after impoundment of the Three Gorges Dam. We suggest that this activity has significantly affected water quality in the dam area. 相似文献
18.
QUATERNARY GLACIATION SERIES ANDGLACIAL LANDFORM IN GONGWANG MOUNTAINS INNORTHEAST PART OF YUNNAN PROVINCE, CHINA 总被引：1，自引：0，他引：1
况明生 《中国地理科学(英文版)》1997,7(2):180-190
Therearemanyquaternaryglaciallandformsinalpineareasahave3100ma.s.1.intheGongWangMountainsinthenortheastpartofYunnanProvinceofChina.TheglaciationseriesandtheglaciallandformsoftheQuaternaryhaveoncebeencoveredinanarticlesketchily(Yietal.,1991).Onthebasisoffieldinvestigationsinrecentyears,we'11goastepfurthertodiscusstheQuaternaryglaciationseriesandtheglacierlandfo~sthereinthisPaper.I.TabsQU~ANANYG~W~TheGOngWangMountainsissituatedbetweentwobranchesoftheJinshaRiver,theXiaojiangandthePudu… 相似文献
19.
Although the mid-late Holocene cold and dry event about 4000 years ago(the 4 ka event) has been observed almost globally, it was most prominent in terrestrial climate proxies from the lower latitudes. Here we evaluate the oceanic response to this event in terms of a Holocene sea surface temperature(SST) record reconstructed using the K'37U index for Core B3 on the continental shelf of the East China Sea. The record reveals a large temperature drop of about 5℃ from the mid-Holocene(24.7℃ at 5.6 ka) to the 4 ka event(19.2℃ at 3.8 ka). This mid-late Holocene cooling period in Core B3 correlated with(i) decreases in the East Asia summer monsoon intensity and(ii) the transition period with increased El Nino/Southern Oscillation activities in the Equatorial Pacific. Our SST record provides oceanic evidence for a more global nature of the mid-late Holocene climate change, which was most likely caused by a southward migration of the Intertropical Converge Zone in response to the decreasing summer solar insolation in the Northern Hemisphere. However, the large SST drop around Core B3 indicates that the mid-late Holocene cooling was regionally amplified by the initiation/strengthening of eddy circulation/cold front which caused upwelling and resulted in additional SST decrease. Upwelling during the mid-late Holocene also enhanced with surface productivity in the East China Sea as reflected by higher alkenone content around Core B3. 相似文献
20.
Kosmas Pavlopoulos Aris Leontaritis Constantin D. Athanassas Chara Petrakou Dimitris Vandarakis Kosnstantinos Nikolakopoulos Leonidas Stamatopoulos Katherina Theodorakopoulou 《山地科学学报》2018,15(5):948-965
This study deals with the analysis of the glacial processes that have affected the relief of Mt Chelmos in northern Peloponnesus, Greece during middle and Late Pleistocene. The goal was to compile a combined geomorphological-geological map of the study area which would enable the chronological stratification of the glacial landforms cropping up on Mt. Chelmos. Chronological stratification was further aided by optically stimulated luminescence (OSL) dating. The map served as the basis upon which the reconstruction and discussion on the phases of the Middle-Late Quaternary paleoclimatic history of Mt. Chelmos have been made. A sophisticated semiautomated method was first used to analyze the Digital Elevation Model (DEM), combined with Aster, Quickbird and ALOS imagery in order to identify glacial and periglacial, as well as karstic features. Then, these features along with other nonrecognizable features from the remote-sensing images were documented in the field. In this way, several glacial landforms were identified, such as moraines and cirques, indicating extended glaciation phases during the middle and Late Pleistocene. Additionally, a ground moraine located at an altitude of 1900-2050 m, within the Spanolakos glacial valley, was dated using the OSL-dating method. The resulting ages indicate a phase of glacier advance/stabilization during MIS-5b (89-86 ka), which is in consistence with pollenrecord evidence from Greece and the Mediterranean. 相似文献