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山东邹平铜矿床上方地气流的组分特征及赋存状态研究 被引量:16
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作者 伍宗华 金仰芬 《物探与化探》 CAS CSCD 1996年第1期14-22,共9页
本文介绍了用光电子能谱分析(XPS)研究地气流组分特征及赋存状态的研究方法以及在山东邹平隐伏铜矿床上方的研究结果。研究的结果表明,地气流中的某些特征组分与深部铜矿床有关,有些组分与表层土壤有关。Au、Ag、Cu、Pb... 本文介绍了用光电子能谱分析(XPS)研究地气流组分特征及赋存状态的研究方法以及在山东邹平隐伏铜矿床上方的研究结果。研究的结果表明,地气流中的某些特征组分与深部铜矿床有关,有些组分与表层土壤有关。Au、Ag、Cu、Pb等元素多呈单质、硫化物和氧化物形式存在,还在某些未知化合物中,存在有负价态的AU。 展开更多
关键词 铜矿床 地气流 组分特征 赋存状态
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Review on the Development of Oil and Gas Flow in Underground Porous Media 被引量:1
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作者 李军诗 王晓冬 +1 位作者 刘鹏程 侯晓春 《Petroleum Science》 SCIE CAS CSCD 2004年第4期88-94,共7页
Through reviewing the flow theory’s birth and development history in underground porous media and contrasting the mechanics of underground fluids and mechanics of viscous fluids, this paper points out the main facto... Through reviewing the flow theory’s birth and development history in underground porous media and contrasting the mechanics of underground fluids and mechanics of viscous fluids, this paper points out the main factors, which affect the development of the theory on oil and gas porous flow. The development law and development route of the mechanics of fluids in porous media are also summarized in this paper. 展开更多
关键词 Porous flow mechanics of fluids in porous media viscous fluids mechanics of ground water petroleum and natural gas engineering REVIEW PROGRESSION
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Study on the Floating Plant Climatic Adaptation of Undercurrent Constructed Wetland in North China 被引量:3
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作者 赵振国 刘丽 《Agricultural Science & Technology》 CAS 2011年第9期1331-1333,共3页
[Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia(Bl.) Backer were planted in the aquatic biologi... [Objective] The aim was to choose appropriate floating plant in the wetland in the north China.[Method] Pistia stratiotes L.,Eichhornia crassipes,and Hydrocharis dubia(Bl.) Backer were planted in the aquatic biological pool of constructed subsurface flow wetland system in the reservoir.Through filed investigation,the growth of the three kinds of plants was studied and their adaptability to the northern climate was concluded.[Result] Judging from the growth speed and state of the three kinds of floating plants,the biological characteristic of Pistia stratiotes L.can perfectly adapt the environment in the pool in the reservoir,followed by the Eichhornia crassipes.The growth state of the Hydrocharis dubia(Bl.) Backer was the worst one and it can not adapt to the north environment.[Conclusion] It provided references for the choice of artificial floating plant in the north area. 展开更多
关键词 North China Undercurrent constructed wetland Duckwood Climatic adaptation
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神奇纷呈的几个案例
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作者 程干泽 《飞碟探索》 1995年第4期28-29,共2页
一位友好的访客 1965年3月1日星期二,加利福尼亚州本罗克斯维尔有位60岁的退休码头工人约翰·F.里夫斯,碰上了一位可爱的天外来客。当时他正乘春日的下午,在维基·瓦奇和布罗克斯维尔之间的一段路上散步,突然,他看到前面400米... 一位友好的访客 1965年3月1日星期二,加利福尼亚州本罗克斯维尔有位60岁的退休码头工人约翰·F.里夫斯,碰上了一位可爱的天外来客。当时他正乘春日的下午,在维基·瓦奇和布罗克斯维尔之间的一段路上散步,突然,他看到前面400米远处有只飞碟,直径10米、高约2米。飞碟停在地上,身下起落架有4只脚。该机械物呈兰绿,偏红,上部有两个舷窗。当里夫斯走到30米左右近处时,有个生物走出飞碟,向他跑来,在离他约5米的地方停住,里夫斯得以从容地朝他打量。 展开更多
关键词 小个子 码头工人 斯维尔 驾驶员 1965年 飞碟 外来客 加利福尼亚州 地球人 地气流
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Study on Airflow Field of Condensing Zone in Compact Spinning System with Perforated Drum 被引量:2
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作者 高金霞 邹专勇 程隆棣 《Journal of Donghua University(English Edition)》 EI CAS 2010年第5期606-609,共4页
Negative pressure plays a very important role in compact spinning system.To know airflow field and its distribution is helpful to look into the condensing principle of fiber bundle.Therefore,computational fluid dynami... Negative pressure plays a very important role in compact spinning system.To know airflow field and its distribution is helpful to look into the condensing principle of fiber bundle.Therefore,computational fluid dynamics(CFD)software was used to simulate airflow field in this paper.Airflow velocity distributions both in different fiber layers and under different negative pressures were discussed.The results indicate that airflow velocity in upper layer of the fiber bundle is greater than that in lower layer.Airflow velocities in both X and Y axis directions have a positive correlation with negative pressure.It can provide a theoretical base to make high quality compact yarns in productive practice. 展开更多
关键词 compact spinning perforated drum condensing zone airflow field
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Gaseous Loss of Nitrogen from Fertilizers Applied to Wheat on a Calcareous Soil in North China Plain 被引量:18
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作者 CAIGUIXIN YANGZHEN 《Pedosphere》 SCIE CAS CSCD 1998年第1期45-52,共8页
Nitrogen (N) losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated. Ammonia volatilization was determined by a micrometeorological method (ammonia samp... Nitrogen (N) losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated. Ammonia volatilization was determined by a micrometeorological method (ammonia sampler), total N loss was estimated by the 15N mass balance method, and denitrification loss was measured by the difference method (calculated from the difference between the total N loss and ammonia loss)and a direct method (measuring the emission of (N2+N2O)-15N ). Total ammonia losses from ammonium bicarbonate and urea in 33 days were 8.7% and 0.9% of the applied nitrogen, respectively. The corresponding total N losses were 21.6% and 29.5%. Apparent denitrification losses (by the difference method) were rather high, being 12.9% from ammonium bicarbonate and 28.6% from urea. However, no emission of (N2+N2O)-15N was detected using the direct method. 展开更多
关键词 ammonia volatilization denitrification loss nitrogen fertilizer WHEAT
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Effect of Ventilation Strategies on Particle Distribution in a Two-Zone Ventilated Room 被引量:2
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作者 钟珂 杨秀峰 +2 位作者 亢燕铭 陈勇航 熊晓洁 《Journal of Donghua University(English Edition)》 EI CAS 2011年第2期165-169,共5页
A computational fluid dynamic ( CFD ) analysis of air movement and aerosol particle transport in a two-zone ventilated room with an inter-zonal opening is presented to study the impact of ventilation strategies and ... A computational fluid dynamic ( CFD ) analysis of air movement and aerosol particle transport in a two-zone ventilated room with an inter-zonal opening is presented to study the impact of ventilation strategies and size of the opening on indoor particle dispersion and concentration distribution. The comparisons of average particle concentrations in both zones between the computations and the experiments from the literature are generally satisfactory and acceptable. The combined effects of sizes of the opening and the inlet and outlet locations (three different strategies) are simulated and discussed. The results show that ventilation strategy and size of the opening influence the particle removal rate in zone 1. The removal rate is decreased when the air supply system is changed from the tap-inlet to the bottom-inlet configuration. The top-inlet system obtains a better particle deposition in zone I than the bottom-inlet configuration. However, the particle concentration at breathing level is lower for bottomsupply system than for top-supply. Decreasing the size of interzonal opening increases the particle deposition rate in zone 1 only for the top.supply system, especially for coarse particles. 展开更多
关键词 ventilating strategy two-zone room AIRFLOW PARTICLE removal rate
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Detecting Changes in Precipitation and Temperature Extremes over China Using a Regional Climate Model with Water Table Dynamics Considered 被引量:1
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作者 QIN Pei-Hua XIE Zheng-Hui WANG Ai-Wen 《Atmospheric and Oceanic Science Letters》 CSCD 2014年第2期103-109,共7页
Simulations were conducted with the regional climate model RegCM incorporating water table dynamics from 1 September 1982 to 28 August 2002 to detect precipitation and temperature extremes. Compared with observed r10(... Simulations were conducted with the regional climate model RegCM incorporating water table dynamics from 1 September 1982 to 28 August 2002 to detect precipitation and temperature extremes. Compared with observed r10(number of days with precipitation ≥ 10 mm d–1), RegCM3_Hydro(the regional climate model with water table dynamics considered) simulated rain belts, including those in southern China and the middle and lower reaches of the Yangtze River, and provided data for arid to semi-arid areas such as the Heihe River Basin in northwestern China. RegCM3_Hydro indicated a significant increasing trend of r95p(days with daily precipitation greater than the 95th percentile of daily amounts) for the Yangtze, Yellow, and Pearl River basins, consistent with r95p observations. The Haihe River Basin was also chosen as a specific case to detect the effect of groundwater on extreme precipitation using peaks over threshold(POT)-based generalized Pareto distribution(GPD) with parameters estimated by the L-moment method. Quantile plots showed that all but a few of the plotted points were distributed near diagonal lines and the modeled data fitted well with the samples. Finally, the effects of water table dynamics on temperature extremes were also evaluated. In the Yellow River Basin and Songhuajiang River Basin, the trends of the number of warm days(TX95n) from RegCM3_Hydro matched observed values more closely when water table dynamics were considered, and clearly increasing numbers of warm days from 1983 to 2001 were detected. 展开更多
关键词 climatic extreme GROUNDWATER RUNOFF river basin regional climate
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Variability of Surface Sensible Heat Flux over Northwest China 被引量:6
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作者 ZHOU Lian-Tong WU Ren-Guang HUANG Rong-Hui 《Atmospheric and Oceanic Science Letters》 2010年第2期75-80,共6页
The present study documents the variability of surface sensible heat flux over Northwest China using station observations for the period 1961 2000.It is found that the afternoon and nighttime sensible heat flux variat... The present study documents the variability of surface sensible heat flux over Northwest China using station observations for the period 1961 2000.It is found that the afternoon and nighttime sensible heat flux variations are remarkably different.The variability of the instant flux in the afternoon is much larger than in the nighttime.The afternoon and nighttime flux anomalies tend to be opposite.The diurnal and seasonal dependence of sensible heat flux variations is closely related to the diurnal cycle of mean land-air temperature difference.The relationship of sensible heat flux with land-air temperature difference based on the instant value differs from that based on the daily mean.The present study indicates the importance for the models to properly simulate mean land-air temperature difference and its diurnal and seasonal variations in order to capture surface sensible heat flux variability over Northwest China and predicts its plausible impacts on climate. 展开更多
关键词 sensible heat flux land-air temperature difference wind speed
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Streamflow and Soil Moisture of Agroforestry and Grass Watersheds in Hilly Area 被引量:8
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作者 LIUGang-Cai TIANGuang-Long +2 位作者 SHUDong-Cai LINSan-Yi LIUShu-Zhen 《Pedosphere》 SCIE CAS CSCD 2004年第2期263-268,共6页
A study was conducted in a hilly area of Sichuan Province,Southwestern China, to compare the streamflow and soil moisture in two upland watersheds with different land use patterns. One was an agroforestry watershed, w... A study was conducted in a hilly area of Sichuan Province,Southwestern China, to compare the streamflow and soil moisture in two upland watersheds with different land use patterns. One was an agroforestry watershed, which consisted mainly of trees with alder (Alnus cremastogyne Burkill) and cypress (Cupressus funebris Endl.) planted in belts or strips with a coverage of about 46%, and the other was a grassland primarily composed of lalang grass (Imperata cylindrica var. major (Nees) C. E. Hubb.), filamentary clematis (Clematis filamentosa Dunn) and common eulaliopsis (Eulaliopsis binata (Retz.) C. E. Hubb) with a coverage of about 44%. Streamflow measurement with a hydrograph established at the watershed outlet showed that the average annual streamflow per 100 mm rainfall from 1983 to 1992 was 0.36 and 1.08 L s-1 km-2 for the agroforestry watershed and the grass watershed, respectively. This showed that the streamflow of the agroforestry watershed was reduced by 67% when compared to that of the grass watershed. The peak average monthly streamflow in the agroforestry watershed was over 5 times lower than that of the grass watershed and lagged by one month. In addition, the peak streamflow during a typical rainfall event of 38.3 mm in August 1986 was 37% lower in the agroforestry watershed than in the grass watershed. Results of the moisture contents of the soil samples from 3 slope locations (upper, middle and lower slopes) indicated that the agroforestry watershed maintained generally higher soil moisture contents than the grass watershed within 0-20 and 20-80 cm soil depths for the upper slope, especially for the period from May through July. For the other (middle and lower) slopes, soil moisture contents within 20-80 cm depth in the agroforestry watershed was generally lower than those in the grass watershed, particularly in September, revealing that water consumption by trees took place mainly below the plow layer. Therefore, agroforestry land use types might offer a complimentary model for tree-annual crop water utilization. 展开更多
关键词 AGROFORESTRY soil moisture streamflow
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Vegetation Feedback at the Mid-Pliocene 被引量:2
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作者 JIANG Da-Bang 《Atmospheric and Oceanic Science Letters》 CSCD 2013年第5期320-323,共4页
A global atmospheric general circulation model and an asynchronously coupled global atmosphere-biome model are used to simulate vegetation feedback at the mid-Pliocene approximately 3.3 to 3.0 million years ago.For th... A global atmospheric general circulation model and an asynchronously coupled global atmosphere-biome model are used to simulate vegetation feedback at the mid-Pliocene approximately 3.3 to 3.0 million years ago.For that period,the simulated vegetation differed from present conditions at 62% of the global ice-free land surface.Vegetation feedback had little overall impact on the global climate of the mid-Pliocene.At the regional scale,however,the interactive vegetation led to statistically significant increases in annual temperature over Greenland,the high latitudes of North America,the mid-high latitudes of eastern Eurasia,and westem Tibet,and reductions in most of the land areas at low latitudes,owing to vegetation-induced changes in surface albedo. 展开更多
关键词 mid-Pliocene vegetation feedback MODEL
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Statistically Downscaled Summer Rainfall over the Middle-Lower Reaches of the Yangtze River 被引量:6
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作者 GUO Yan LI Jian-Ping LI Yun 《Atmospheric and Oceanic Science Letters》 2011年第4期191-198,共8页
The summer rainfall over the middle-lower reaches of the Yangtze River valley (YRSR) has been estimated with a multi-linear regression model using principal atmospheric modes derived from a 500 hPa geopotential height... The summer rainfall over the middle-lower reaches of the Yangtze River valley (YRSR) has been estimated with a multi-linear regression model using principal atmospheric modes derived from a 500 hPa geopotential height and a 700 hPa zonal vapor flux over the domain of East Asia and the West Pacific.The model was developed using data from 1958 92 and validated with an independent prediction from 1993 2008.The independent prediction was efficient in predicting the YRSR with a correlation coefficient of 0.72 and a relative root mean square error of 18%.The downscaling model was applied to two general circulation models (GCMs) of Flexible Global Ocean-Atmosphere-Land System Model (FGOALS) and Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1 (GFDL-CM2.1) to project rainfall for present and future climate under B1 and A1B emission scenarios.The downscaled results pro-vided a closer representation of the observation compared to the raw models in the present climate.In addition,compared to the inconsistent prediction directly from dif-ferent GCMs,the downscaled results provided a consistent projection for this half-century,which indicated a clear increase in the YRSR.Under the B1 emission scenario,the rainfall could increase by an average of 11.9% until 2011 25 and 17.2% until 2036 50 from the current state;under the A1B emission scenario,rainfall could increase by an average of 15.5% until 2011 25 and 25.3% until 2036 50 from the current state.Moreover,the increased rate was faster in the following decade (2011 25) than the latter of this half-century (2036 50) under both emissions. 展开更多
关键词 statistical downscaling summer rainfall Yangtze River future scenario
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Impact of land-cover and climate changes on runoff of the source regions of the Yellow River 被引量:6
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作者 李道峰 田英 +1 位作者 刘昌明 HAO Fanghua 《Journal of Geographical Sciences》 SCIE CSCD 2004年第3期330-338,共9页
After dividing the source regions of the Yellow River into 38 sub-basins, thepaper made use of the SWAT model to simulate streamflow with validation and calibration of theobserved yearly and monthly runoff data from t... After dividing the source regions of the Yellow River into 38 sub-basins, thepaper made use of the SWAT model to simulate streamflow with validation and calibration of theobserved yearly and monthly runoff data from the Tangnag hydrological station, and simulationresults are satisfactory. Five land-cover scenario models and 24 sets of temperature andprecipitation combinations were established to simulate annual runoff and runoff depth underdifferent scenarios. The simulation shows that with the increasing of vegetation coverage annualrunoff increases and evapotranspiration decreases in the basin. When temperature decreases by 2℃and precipitation increases by 20%, catchment runoff will increase by 39.69%, which is the largestsituation among all scenarios. 展开更多
关键词 distributed hydrological model source regions of the Yellow River scenariosimulation changing environment
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Possible connection between anomalous activity of Scandinavian Atmospheric Teleconnection Pattern and winter snowfall in the Yangtze-Huaihe River Basin of China 被引量:1
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作者 ZHU Lin CHEN Haishan 《Atmospheric and Oceanic Science Letters》 CSCD 2019年第3期218-225,共8页
The temporal and spatial characteristics of winter snowfall in the Yangtze–Huaihe River Basin (YHRB) of China and its possible connection with Scandinavian Atmospheric Teleconnection Pattern (SCAND) anomalies are exp... The temporal and spatial characteristics of winter snowfall in the Yangtze–Huaihe River Basin (YHRB) of China and its possible connection with Scandinavian Atmospheric Teleconnection Pattern (SCAND) anomalies are explored based on daily meteorological data contained in the Daily Surface Climate Dataset for China (V3.0) during the period 1960–2012. Results show that winter snowfall in the YHRB exhibits consistent anomalies over the whole region for the interannual variation during 1960–2012. Further analysis suggests that winter snowfall anomalies in the YHRB are closely linked to the anomalous wintertime SCAND activity. When there is more winter snowfall in the YHRB, SCAND is usually in a positive phase, accompanied by a strengthened Urals blocking high and East Asian trough, which is conducive to strengthened cold-air activity, intensified vertical motions, and more water vapor transport in the YHRB. In contrast, less winter snowfall in the YHRB usually happens in the negative phase of SCAND. Our results provide useful information to better understand the relevant mechanism responsible for anomalous winter snowfall in this area. 展开更多
关键词 Winter snowfall Yangtze– Huaihe River Basin atmospheric general circulation Scandinavian Atmospheric Teleconnection Pattern
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Close relationship between the East Asian westerly jet and Russian far East surface air temperature in summer 被引量:1
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作者 LIN Xiao-Zhen LI Chao-Fan +1 位作者 LIN Zhong-Da LU Ri-Yu 《Atmospheric and Oceanic Science Letters》 CSCD 2018年第3期282-286,共5页
The interannual variability of the east asian upper-tropospheric westerly jet(EAJ) in summer is characterized by the meridional displacement of its axis, or a seesaw pattern of zonal wind anomalies between the north... The interannual variability of the east asian upper-tropospheric westerly jet(EAJ) in summer is characterized by the meridional displacement of its axis, or a seesaw pattern of zonal wind anomalies between the northern and southern flanks of the EAJ. This study reveals a close relationship between the surface air temperature in the russian far east and the northern flank of the EAJ. Related to a warmer surface in the russian far east, the westerly decelerates in the northern flank of the EAJ. The relationship can be explained by a positive feedback mechanism between the surface air temperature in the russian far east and the overhead circulation: the anticyclonic circulation anomaly related to a weakened westerly in the northern flank of the EAJ induces surface warming in the russian far east and the warmer surface can in turn act as a heat source and induces a local anticyclonic circulation anomaly in the upper troposphere, therefore decelerating the westerly in the northern flank of the EAJ. The result implies that a better description of the summer surface condition in the russian far east may benefit seasonal forecasts of the EAJ and, subsequently, east asian summer climate. 展开更多
关键词 East Asian westerly jet surface air temperature Russian far East
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Variabilities of Surface Current in the Tropical Pacific Ocean 被引量:5
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作者 WANGOi HURuijin AnnaZaklikowski 《Journal of Ocean University of Qingdao》 2002年第2期130-134,共5页
The Simple Ocean Data Assimilation (SODA) package is used to better understand the variabilities of surface current transport in the Tropical Pacific Ocean from 1950 to 1999. Seasonal variation, interannual and decada... The Simple Ocean Data Assimilation (SODA) package is used to better understand the variabilities of surface current transport in the Tropical Pacific Ocean from 1950 to 1999. Seasonal variation, interannual and decadal variability analyses are conducted on the three major surface currents of the Tropical Pacific Ocean: the North Equatorial Current (NEC), the North Equatorial Countercurrent (NECC), and the South Equatorial Current (SEC). The transport of SEC is quite larger than those of NEC and NECC. The SEC has two maximums in February and August. The NEC has a small annual variation. The NECC has a maximum in October and is very weak in March and April. All currents have remarkable interannual and decadal variabilities. The variabilities of the NEC and the SEC relate to the winds over them well, but the relationship between the NECC and the wind over it is not close. Analysis related to El Nio-Southern Oscillation (ENSO) suggests that before El Nio (La Nia) the SEC is weaker (stronger) and the NECC is stronger (weaker), after El Nio (La Nia) the SEC is stronger (weaker) and the SEC is weaker (stronger). There is no notable relationship between the NEC and ENSO. 展开更多
关键词 the North Equatorial Current (NEC) the North Equatorial Countercurrent (NECC) the South Equatorial Current (SEC) the Tropical Pacific Ocean
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Subpolar Gyre Index and the North Atlantic Meridional Overturning Circulation in a Coupled Climate Model 被引量:1
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作者 GAO Yong-Qi YU Lei 《Atmospheric and Oceanic Science Letters》 2008年第1期29-32,共4页
The subpolar gyre index (SPG), derived from the analysis of sea surface height (SSH), is proposed to be a potential indicator for the North Atlantic Meridional Overturning Circulation (AMOC) based on observation as we... The subpolar gyre index (SPG), derived from the analysis of sea surface height (SSH), is proposed to be a potential indicator for the North Atlantic Meridional Overturning Circulation (AMOC) based on observation as well as the Ocean General Circulation Model (OGCM). We investigated the correspondence between the SPG and the AMOC in a coupled climate model. Our results confirm that the SPG can be used as an early indicator for the AMOC in the subtropical North Atlantic. Changes in the SPG are closely related to variations in the air-sea heat exchange in the Labrador Sea, and variations in deep water formation and southward dense water transport with the deep western boundary current (DWBC) in the North Atlantic. 展开更多
关键词 subpolar gyre index North Atlantic merid-ional overturning circulation INDICATOR
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Impact of Meteorological Drought on Streamflow Drought in Jinghe River Basin of China 被引量:5
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作者 ZHAO Lin LYU Aifeng +5 位作者 WU Jianjun Michael HAYES TANG Zhenghong HE Bin LIU Jinghui LIU Ming 《Chinese Geographical Science》 SCIE CSCD 2014年第6期694-705,共12页
Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or... Under global climate change, drought has become one of the most serious natural hazards, affecting the ecological environment and human life. Drought can be categorized as meteorological, agricultural, hydrological or socio-economic drought. Among the different categories of drought, hydrological drought, especially streamflow drought, has been given more attention by local governments, researchers and the public in recent years. Identifying the occurrence of streamflow drought and issuing early warning can provide timely information for effective water resources management. In this study, streamflow drought is detected by using the Standardized Runoff Index, whereas meteorological drought is detected by the Standardized Precipitation Index. Comparative analyses of frequency, magnitude, onset and duration are conducted to identify the impact of meteorological drought on streamflow drought. This study focuses on the Jinghe River Basin in Northwest China, mainly providing the following findings. 1) Eleven meteorological droughts and six streamflow droughts were indicated during 1970 and 1990 after pooling using Inter-event time and volume Criterion method. 2) Streamflow drought in the Jinghe River Basin lagged meteorological drought for about 127 days. 3) The frequency of streamflow drought in Jinghe River Basin was less than meteorological drought. However, the average duration of streamflow drought is longer. 4) The magnitude of streamflow drought is greater than meteorological drought. These results not only play an important theoretical role in understanding relationships between different drought categories, but also have practical implications for streamflow drought mitigation and regional water resources management. 展开更多
关键词 streamflow drought meteorological drought Standardized Precipitation Index (SPI) Standardized Runoff Index (SRI) timelag Jinghe River Basin
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Exploration of regional surface average heat flow from meteorological and geothermal series 被引量:1
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作者 刘迁迁 魏东平 +1 位作者 孙振添 张晓惠 《Applied Geophysics》 SCIE CSCD 2013年第4期496-505,513,共11页
We attempt to compute the Surface Average Heat Flow (SAHF) from long-term temperature observations of one hundred seventy-seven observational points at the depths of 0.8, 1.6, and 3.2 m, which were relatively evenly... We attempt to compute the Surface Average Heat Flow (SAHF) from long-term temperature observations of one hundred seventy-seven observational points at the depths of 0.8, 1.6, and 3.2 m, which were relatively evenly distributed in China's Mainland. We first employ Fourier transformation to remove the influence of atmospheric temperature variations from the observation series, which are classified into the type of the steady-state temperature monotonously increasing with depth (type I) and other three types. Then we compare our results obtained from the data of type I, of which the values are thought to equal to those of the mean borehole heat flow, with those obtained from traditional heat flow observations mainly distributed in North China Craton. In computations of the SAHF at the observation stations, we deduce the thermal diffusivity and volumetric specific heat of the soil by employing harmonic solutions of the heat conduction equation for the same moisture group as the first step, and then we determine the SAHF using Fourier's law. Our results indicate that the SAHF derived from shallow earth geothermal data can reflect the heat flow field to a large extent. 展开更多
关键词 Meteorological and geothermal series Surface average heat flow Heat flow Soil thermal diffusivity Soil volumetric specific heat
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DCT ANALYSIS DISTRIBUTION FEATURES OF NEAR-SURFACE WIND FIELDS DURING THE LANDFALL OF VONGFONG
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作者 李江南 王安宇 +3 位作者 杨兆礼 李国丽 吴池胜 侯尔滨 《Journal of Tropical Meteorology》 SCIE 2003年第2期143-151,共9页
Based on the QuikSCAT data, the features of surface wind distribution of the typhoon Vongfong landfall process are analyzed. We have also studied the variance spectral configuration of the surface wind field using DCT... Based on the QuikSCAT data, the features of surface wind distribution of the typhoon Vongfong landfall process are analyzed. We have also studied the variance spectral configuration of the surface wind field using DCT (Discrete Cosine Transform). The conclusions are as follows: The near-surface wind field is highly asymmetric; the variance components of asymmetric surface wind field depend mainly on the airflow direction of wavenumber 1 and 2. When the typhoon moves west, there are two wave spectral centers lining up in the zonal direction, mainly the airflow from zonal wavenumber 2 and meridional wavenumber 2; when it moves north, there are two wave spectral centers in a meridional array, mainly the airflow from zonal wavenumber 1 and meridional wavenumber 2. The airflow for wavenumber 1 mainly contributes to the variance of the tangential wind while that for wavenumber 2 to the variance of the radial wind. The asymmetrical distribution changes with the large-scale environment and self-rotating circulation around the typhoon. When it approached land, the associated gale appears in front portion in the advancing direction of the storm. It is in effect similar to the model of Chen Lian-shou for typhoon-related gales NNW on the left front portion and SE on the right front portion. 展开更多
关键词 wind distribution ASYMMETRIC spectral configuration DCT
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