期刊文献+
共找到89篇文章
< 1 2 5 >
每页显示 20 50 100
Review on the Development of Oil and Gas Flow in Underground Porous Media 被引量:1
1
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
下载PDF
Application of seismic multi-attribute fusion method based on D-S evidence theory in prediction of CBM-enriched area 被引量:1
2
作者 祁雪梅 张绍聪 《Applied Geophysics》 SCIE CSCD 2012年第1期80-86,116,117,共9页
D-S evidence theory provides a good approach to fuse uncertain inlbrmation. In this article, we introduce seismic multi-attribute fusion based on D-S evidence theory to predict the coalbed methane (CBM) concentrated... D-S evidence theory provides a good approach to fuse uncertain inlbrmation. In this article, we introduce seismic multi-attribute fusion based on D-S evidence theory to predict the coalbed methane (CBM) concentrated areas. First, we choose seismic attributes that are most sensitive to CBM content changes with the guidance of CBM content measured at well sites. Then the selected seismic attributes are fused using D-S evidence theory and the fusion results are used to predict CBM-enriched area. The application shows that the predicted CBM content and the measured values are basically consistent. The results indicate that using D-S evidence theory in seismic multi-attribute fusion to predict CBM-enriched areas is feasible. 展开更多
关键词 D-S evidence theory CBM seismic attributes thsion
下载PDF
EFFECTS ON ENDOCRINAL FUNCTION TREATED WITH ACUPUNCTURE BASED ON QIJIE THEROY IN EPILEPSY PATIENTS
3
作者 陈兴华 章闻 杨海涛 《World Journal of Acupuncture-Moxibustion》 2008年第4期1-8,共8页
Objective To explore the effects on endocrinal function treated with acupuncture based on Qijie (the pathway of qi) theory in epilepsy patients. Methods A total of 60 epilepsy patients were randomly divided into acu... Objective To explore the effects on endocrinal function treated with acupuncture based on Qijie (the pathway of qi) theory in epilepsy patients. Methods A total of 60 epilepsy patients were randomly divided into acupuncture and medication group (n--30), and single medication group (n = 30). Both groups were taken antiepileptic drugs, sodium valproate regularly. The acupoints of Fengfu(风府 GV 16),TiEmzhu (天柱 BL 10) and Renying (人迎 ST 9) were selected as major points according to Qijie theory (气街理论) in acupuncture and medication group. The plasma levels of cortisol (CORT), estrogen (E2), progesterone (Prog), pituitary prolactin (PRL), and epilepsy score were observed successively in both enrolled groups in pre-treatment and post-treatment. The outcomes were statistically analyzed. Results The effective rate was 96.7% in either group, and there was no significant differences; the epilepsy score was (13. 584.01) in pre- treatment and (7.86 ___4.90) in post-treatment in acupuncture and medication group and those in single medi- cation group were (12.97 ± 3. 91) and (7. 86 ± 4.90) respectively, indicating apparent improvement (P〈O. 05). The increase of CORT in acupuncture and medication group indicated significant difference in post-treatment compared with that in single medication group (P = 0.046). The differences of E2, PRL, Prog in post-treatment in two groups showed no statistical significance (P〉0. 05). More effects had been a- chieved in acupuncture and medication group on endocrinal function and controlling epileptic seizures in epilepsy patients. Conclusion Acupuncture treatment based on Qijie theory is effective on improving endocrinal function in epilepsy patients. 展开更多
关键词 Qijie theory Acupuncture Epilepsy Endocrinal function
下载PDF
鱼类生态学研究的先驱——宋应星
4
作者 明时 《渔业经济研究》 1988年第2期48-48,27,共2页
“鱼儿离不开水,”这是连小孩都知道的常识,但要问个所以然,恐怕就未必都能说清其中的道理。在我国古代。二千多年前《庄子·至乐篇》中就说过:“鱼处水而生”,但寻根究底地探讨鱼水关系的奥秘,却是很久以后的事了。明代杰出... “鱼儿离不开水,”这是连小孩都知道的常识,但要问个所以然,恐怕就未必都能说清其中的道理。在我国古代。二千多年前《庄子·至乐篇》中就说过:“鱼处水而生”,但寻根究底地探讨鱼水关系的奥秘,却是很久以后的事了。明代杰出的科学家宋应星(1587—?),以著被誉为“中国古代科技百科全书”的《天工开物》而驰名中外。在他的另一部著作《论气》中,就对鱼类的这种生态进行过很有价值的研究。 展开更多
关键词 鱼类生态学 宋应星 明代 《论气》 鱼水关系 理论研究
下载PDF
MULTI-OBJECTIVE SHAPE DESIGN IN AERODYNAMICS USING GAME STRATEGY 被引量:1
5
作者 唐智礼 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第3期195-199,共5页
Multi-objective optimization for the optimum shape design is introduced in aerodynamics using the Game theory. Based on the control theory, the employed optimizer and the negative feedback are used to implement the co... Multi-objective optimization for the optimum shape design is introduced in aerodynamics using the Game theory. Based on the control theory, the employed optimizer and the negative feedback are used to implement the constraints. All the constraints are satisfied implicitly and automatically in the design. Furthermore,the above methodology is combined with a formulation derived from the Game theory to treat multi-point airfoil optimization. Airfoil shapes are optimized according to various aerodynamics criteria. In the symmetric Nash game, each “player” is responsible for one criterion, and the Nash equilibrium provides a solution to the multipoint optimization. Design results confirm the efficiency of the method. 展开更多
关键词 Game theory multi-objective optimization aerodynamic design constrained optimal control theory
下载PDF
A Review of Interaction Between Neon Flying Squid(Ommastrephes bartramii) and Oceanographic Variability in the North Pacific Ocean 被引量:26
6
作者 YU Wei CHEN Xinjun +1 位作者 YI Qian TIAN Siquan 《Journal of Ocean University of China》 SCIE CAS 2015年第4期739-748,共10页
The neon flying squid (Ommastrephes bartramii) is a short-lived opporttmistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic... The neon flying squid (Ommastrephes bartramii) is a short-lived opporttmistic species widely distributed in subtropical and temperate waters in the North Pacific Ocean. The life cycle of O. bartramii from planktonic eggs to nektonic adults is closely linked to oceanographic conditions. The fluctuations in O. bartramii abundance and distribution tend to increase and widen continu- ously due to the heavy influences of ocean-climate events on various spatio-temporal scales. In this study, we reviewed the interac- tion between O. bartramii and oceanography variability in the North Pacific with respect to large-scale climatic-oceanic phenomena including E1 Nifio, La Nifia, Kuroshio, Oyashio and Pacific Decadal Oscillation (PDO), as well as regional environmental variables such as sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), chlorophyll-a (Chl-a) concentration, and plankton density. The population dynamics of O. bartramii is mediated mainly by meso- and large-scale climatic-oceanic events (e.g., Kuroshio and Oyashio Currents) rather than other local environmental conditions (e.g., SST and Chl-a concentration), because all of the oceanographic influences are imposed on the context of large-scale climate changes (e.g., PDO). An unstructured-grid finite- volume coastal ocean model coupled with an individual-based model is proposed to simulate relevant physical-biological oceano- graphic processes for identifying ocean-climate influence and predicting O. bartramii distribution and abundance in the North Pacific. Future research needs to be focused on improving the knowledge about early life history of O. bartramii and evaluating the relation- ship between marine physical environment and two separate passive drifting life stages of O. bartramii including free-floating eggs and planktonic paralarvae. 展开更多
关键词 Ommastrephes bartramii oceanographic influence early life history physical-biological model North Pacific Ocean
下载PDF
Review of Rapid Transformation of Floodplain Wetlands in Northeast China: Roles of Human Development and Global Environmental Change 被引量:4
7
作者 YU Xiaofei DING Shanshan +3 位作者 ZOU Yuanchun XUE Zhenshan LYU Xianguo WANG Guoping 《Chinese Geographical Science》 SCIE CSCD 2018年第4期654-664,共11页
Northeast China is the region with the largest area of wetlands in China. The Sanjiang Plain and the Songnen Plain are large freshwater marsh distribution regions that are affected by climate warming and by the increa... Northeast China is the region with the largest area of wetlands in China. The Sanjiang Plain and the Songnen Plain are large freshwater marsh distribution regions that are affected by climate warming and by the increasing frequency and density of extreme weather and are the regions most subject to disturbances by human activities in Northeast China. The wetlands of the Sanjiang Plain and the Songnen Plain have shrunk severely in the past 60 years, and wetland functions have been reduced substantially because of climate change, unreasonable land use, fire episodes, engineering and construction works and urbanization. Large-scale agricultural development started in the 1950 s has been the most important driving factor for wetland loss and degradation in the Sanjiang Plain. Water shortage has been the most important factor for degradation and fragmentation of wetlands in the Songnen Plain. To mitigate wetland degradation and better protect wetlands, special regulations, long-term mechanisms and technical support of wetland protection should be established. A wetland compensation program should be implemented, and technologies for increasing the adaptive capacity of wetlands should be developed. Moreover, it is most important to find the balanced threshold between agricultural development and wetland protection. 展开更多
关键词 WETLAND climate change human activities wetland recovery Sanjiang Plain Songnen Plain
下载PDF
Wind-induced responses of super-large cooling towers 被引量:3
8
作者 柯世堂 葛耀君 +2 位作者 赵林 陈少林 Y.Tamura 《Journal of Central South University》 SCIE EI CAS 2013年第11期3216-3228,共13页
Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formula... Traditional gust load factor(GLF)method,inertial wind load(IWL)method and tri-component method(LRC+IWL)cannot accurately analyze the wind-induced responses of super-large cooling towers,so the real combination formulas of fluctuating wind-induced responses and equivalent static wind loads(ESWLSs)were derived based on structural dynamics and random vibration theory.The consistent coupled method(CCM)was presented to compensate the coupled term between background and resonant response.Taking the super-large cooling tower(H=215 m)of nuclear power plant in Jiangxi Province,China,which is the highest and largest in China,as the example,based on modified equivalent beam-net design method,the aero-elastic model for simultaneous pressure and vibration measurement of super-large cooling tower is firstly carried out.Then,combining wind tunnel test and CCM,the effects of self-excited force on the surface pressures and wind-induced responses are discussed,and the wind-induced response characteristics of background component,resonant component,coupled term between background and resonant response,fluctuating responses,and wind vibration coefficients are discussed.It can be concluded that wind-induced response mechanism must be understood to direct the wind resistant design for super-large cooling towers. 展开更多
关键词 super-large cooling towers wind-induced responses wind vibration coefficients aero-elastic model consistent coupled method
下载PDF
Influence of climate and tectonic movements on granite landforms in China 被引量:5
9
作者 陈艺鑫 崔之久 杨建强 《Journal of Geographical Sciences》 SCIE CSCD 2009年第5期587-599,共13页
Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical m... Present granite landform characteristics and distribution are the integrated result of climate, tectonics and lithology. Various types of granite landforms in China signify climate zonality and differential vertical movement of earth surface, while published research results on Chinese granite landforms are very rare, especially in international journals. Based on the process analysis of chemical weathering and physical disintegration, four granite landform regions in China are classified according to the present climate regime. On the Tibetan Plateau, the cold and freezing climate induced periglacial landscapes; the northeast region is characterized by physical disintegration and low round mounds are widespread; in the northwest region controlled by arid climate, wind-carved minor landscapes are extremely prominent. The most spectacular granite landscapes in China are presented in southeast as a result of Iongtime chemical weathering under humid and warm conditions, as well as the differential uplift after Neogene. Correlating the weathering crust in southern China, Tibetan Plateau and India, a possible unified planation surface in Neogene is proposed. With corestones as indicators of original weathering front, the differential uplift extent of dissected planation surfaces can be estimated. At least three landforms implying uplift can be identified in southeastern China, with elevations of 300-400 m, 2000 m and 3600 m above the sea level respectively. 展开更多
关键词 granite landform WEATHERING planation surface CLIMATE UPLIFT China
下载PDF
A Mass Transfer Model Based on Individual Bubbles and an Unsteady State Film Mechanism 被引量:1
10
作者 赵斌 王铁峰 王金福 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第2期163-168,共6页
A gas-liquid mass transfer model based on an unsteady state film mechanism applied to a single bubble is presented. The mathematical model was solved using Laplace transform to obtain an analytical solution of concent... A gas-liquid mass transfer model based on an unsteady state film mechanism applied to a single bubble is presented. The mathematical model was solved using Laplace transform to obtain an analytical solution of concentration profile in terms of the radial position r and time t. The dynamic mass transfer flux was deduced and the influence of the bubble size was also determined. A mathematical method for deducing the average mass transfer flux directly from the Laplace transformed concentration is presented. Its accuracy is verified by comparing the numerical results with those from the indirect method. The influences of the model parameters, namely, the bubble size R, liquid film thickness δ, and the surface renewal constant s on the average mass transfer flux were investigated. The proposed model is useful for a better understanding of the mass transfer mechanism and an optimum design of gas-liquid contact equipment. 展开更多
关键词 film theory Laplace transformation mass diffusion penetration theory surface renewal theory
下载PDF
A risk-based methodology for the optimal placement of hazardous gas detectors 被引量:4
11
作者 Kang Cen Ting Yao +1 位作者 Qingsheng Wang Shengyong Xiong 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2018年第5期1078-1086,共9页
Hazardous gas detection systems play an important role in preventing catastrophic gas-related accidents in process industries. Even though effective detection technology currently exists for hazardous gas releases and... Hazardous gas detection systems play an important role in preventing catastrophic gas-related accidents in process industries. Even though effective detection technology currently exists for hazardous gas releases and a majority of process installations have a large number of sensitive detectors in place, the actual operating performance of gas detection systems still does not meet the expected requirements. In this paper, a riskbased methodology is proposed to optimize the placement of hazardous gas detectors. The methodology includes three main steps, namely, the establishment of representative leak scenarios, computational fluid dynamics(CFD)-based gas dispersion modeling, and the establishment of an optimized solution. Based on the combination of gas leak probability and joint distribution probability of wind velocity and wind direction, a quantitative filtering approach is presented to select representative leak scenarios from all potential scenarios. The commercial code ANSYS-FLUENT is used to estimate the consequence of hazardous gas dispersions under various leak and environmental conditions. A stochastic mixed-integer linear programming formulation with the objective of minimizing the total leak risk across all representative leak scenarios is proposed, and the greedy dropping heuristic algorithm(GDHA) is used to solve the optimization model. Finally, a practical application of the methodology is performed to validate its effectiveness for the optimal design of a gas detector system in a high-sulfur natural gas purification plant in Chongqing, China. The results show that an appropriate number of gas detectors with optimal cost-effectiveness can be obtained, and the total leak risk across all potential scenarios can be substantially reduced. This methodology provides an effective approach to guide the optimal placement of pointtype gas detection systems involved with either single or mixed gas releases. 展开更多
关键词 Leak scenario Leak risk Gas detection Detector placement Mixed-integer linear programming
下载PDF
Data fusion in oil and gas detection 被引量:2
12
作者 Wang Shoudong 《Applied Geophysics》 SCIE CSCD 2006年第2期120-123,共4页
Data fusion, a new research domain, is the integration and extension of modem information techniques and many other subjects. The data fusion concept is introduced and the Dempster-Shafer evidence deduction is describ... Data fusion, a new research domain, is the integration and extension of modem information techniques and many other subjects. The data fusion concept is introduced and the Dempster-Shafer evidence deduction is described and applied to oil and gas detection. An example of the method is shown using numerical simulation data. The processing result indicates that the data fusion method can be widely used in hydrocarbon detection. 展开更多
关键词 data fusion combining evidence and theory
下载PDF
STUDY OF THE MODIFICATION OF MULTI-MODEL ENSEMBLE SCHEMES FOR TROPICAL CYCLONE FORECASTS 被引量:9
13
作者 张涵斌 智协飞 +2 位作者 陈静 王亚男 王轶 《Journal of Tropical Meteorology》 SCIE 2015年第4期389-399,共11页
This study investigates multi-model ensemble forecasts of track and intensity of tropical cyclones over the western Pacific, based on forecast outputs from the China Meteorological Administration, European Centre for ... This study investigates multi-model ensemble forecasts of track and intensity of tropical cyclones over the western Pacific, based on forecast outputs from the China Meteorological Administration, European Centre for Medium-Range Weather Forecasts, Japan Meteorological Agency and National Centers for Environmental Prediction in the THORPEX Interactive Grand Global Ensemble(TIGGE) datasets. The multi-model ensemble schemes, namely the bias-removed ensemble mean(BREM) and superensemble(SUP), are compared with the ensemble mean(EMN) and single-model forecasts. Moreover, a new model bias estimation scheme is investigated and applied to the BREM and SUP schemes. The results showed that, compared with single-model forecasts and EMN, the multi-model ensembles of the BREM and SUP schemes can have smaller errors in most cases. However, there were also circumstances where BREM was less skillful than EMN, indicating that using a time-averaged error as model bias is not optimal. A new model bias estimation scheme of the biweight mean is introduced. Through minimizing the negative influence of singular errors, this scheme can obtain a more accurate model bias estimation and improve the BREM forecast skill. The application of the biweight mean in the bias calculation of SUP also resulted in improved skill. The results indicate that the modification of multi-model ensemble schemes through this bias estimation method is feasible. 展开更多
关键词 TIGGE data multi-model ensemble tropical cyclone biweight mean
下载PDF
ASSIMILATION OF REAL OBSERVATIONAL DATA WITH THE GSI-HYBRID DATA ASSIMILATION SYSTEM TO IMPROVE TYPHOON FORECAST 被引量:6
14
作者 李泓 骆婧瑶 陈葆德 《Journal of Tropical Meteorology》 SCIE 2015年第4期400-407,共8页
A hybrid GSI (Grid-point Statistical Interpolation)-ETKF (Ensemble Transform Kalman Filter) data assimila- tion system has been recently developed for the WRF (Weather Research and Forecasting) model and tested ... A hybrid GSI (Grid-point Statistical Interpolation)-ETKF (Ensemble Transform Kalman Filter) data assimila- tion system has been recently developed for the WRF (Weather Research and Forecasting) model and tested with simu- lated observations for tropical cyclone (TC) forecast. This system is based on the existing GSI but with ensemble back- ground information incorporated. As a follow-up, this work extends the new system to assimilate real observations to further understand the hybrid scheme. As a first effort to explore the system with real observations, relatively coarse grid resolution (27 km) is used. A case study of typhoon Muifa (2011) is performed to assimilate real observations in- cluding conventional in-situ and satellite data. The hybrid system with flow-dependent ensemble eovariance shows sig- nificant improvements with respect to track forecast compared to the standard GSI system which in theory is three di- mensional variational analysis (3DVAR). By comparing the analyses, analysis increments and forecasts, the hybrid sys- tem is found to be potentially able to recognize the existence of TC vortex, adjust its position systematically, better de- scribe the asymmetric structure of typhoon Muifa and maintain the dynamic and thermodynamic balance in typhoon ini- tial field. In addition, a cold-start hybrid approach by using the global ensembles to provide flow-dependent error is test- ed and similar results are revealed with those from cycled GSI-ETKF approach. 展开更多
关键词 hybrid data assimilation GSI ETKF tropical cyclone
下载PDF
A new numerical approach of coupled modeling for solid deformation and gas leak flow in multi-coal-seams 被引量:5
15
作者 孙培德 郭茂新 《Journal of Coal Science & Engineering(China)》 2005年第1期36-39,共4页
From the viewpoint of interaction mechanics for solid and gas, a coupled mathematical model was presented for solid coal/rock deformation and gas leak flow in parallel deformable coal seams. Numerical solutions using ... From the viewpoint of interaction mechanics for solid and gas, a coupled mathematical model was presented for solid coal/rock deformation and gas leak flow in parallel deformable coal seams. Numerical solutions using the SIP (Strong Implicit Proce- dure) method to the coupled mathematical model for double parallel coal seams were also developed in detail. Numerical simulations for the prediction of the safety range using protection layer mining were performed with experimental data from a mine with potential danger of coal/gas outbursts. Analyses show that the numerical simulation results are consistent with the measured data in situ. 展开更多
关键词 coupled models for solid-gas solid elastic-deformation gas leakage flow strong implicit procedure multi-coal-seams
下载PDF
A DYNAMICAL INTERPRETATION OF THE WIND FIELD IN TROPICAL CYCLONES WITH THE CONSIDERATION OF OROGRAPHIC FACTORS 被引量:4
16
作者 郝世峰 潘劲松 +2 位作者 岳彩军 崔晓鹏 杨诗芳 《Journal of Tropical Meteorology》 SCIE 2010年第2期125-133,共9页
Based on the barotropic primitive equation in the polar coordinate system and the appropriate assumption, we obtained the mathematical equation of orographic forcing on unit mass air parcel. With the consideration of ... Based on the barotropic primitive equation in the polar coordinate system and the appropriate assumption, we obtained the mathematical equation of orographic forcing on unit mass air parcel. With the consideration of the frictional stress of the sea and land, supposing that parcel velocity in tropical cyclones is in linear variation and that the distribution of surface pressure is circular, a set of equations are derived, which describe the impact of orographic slope error, the central pressure error and position error of tropical cyclones on the wind field in the tropical cyclone. Typhoon Wipha (2007) is selected to verify the above interpretation method. The results show that the orographic slope, the frictional coefficient, the intensity and position of the cyclone are the important factors which have great influence on the interpretation of wind information about tropical cyclones. The dynamic interpretation method gives very good results, especially for the coastal area. It is applicable to improving the forecasts of the wind field in tropical cyclones. 展开更多
关键词 tropical cyclone orographic slope frictional stress strong wind dynamic interpretation
下载PDF
THE RELATIONSHIP BETWEEN THE ATMOSPHERIC HEATING SOURCE/SINK ANOMALIES OF ASIAN MONSOON AND FLOOD/DROUGHT IN THE YANGTZE RIVER BASIN IN THE MEIYU PERIOD 被引量:4
17
作者 岑思弦 巩远发 +1 位作者 赖欣 彭亮 《Journal of Tropical Meteorology》 SCIE 2015年第4期352-360,共9页
NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 1... NCEP/NCAR reanalysis data and a 30-year precipitation dataset of observed daily rainfall from 109 gauge stations are utilized in this paper.Using the REOF we analyzed the spatial distribution of precipitation in the 109 stations in the Yangtze River Basin in Meiyu periods from 1978 to 2007.The result showed that the spatial distribution of precipitation in the Yangtze River Basin can be divided into the south and north part.As a result,relationships between an atmospheric heating source(hereafter called <Q_1>) over the Asian region and the precipitation on the south and north side of Yangtze River in Meiyu periods were separately studied in this paper.The results are shown as follows.The flood/drought to the north of Yangtze River(NYR) was mainly related to the <Q_1> over the East Asia summer monsoon region:when the <Q_1> over the Philippines through Western Pacific and the south China was weakened(strengthened),it would probably result in the flood(drought) in NYR;and the precipitation on the south side of Yangtze River(SYR)was related to the <Q_1> over the east Asia and Indian summer monsoon region:when the <Q_1> over the areas from south China to the northern East China Sea and Yellow Sea and south-eastern Japan was strengthened(weakened),and the <Q_1> over the areas from the Bay of Bengal to south-eastern Tibetan Plateau was weakened(strengthened),it will lead to flood(drought) in SYR. 展开更多
关键词 atmospheric heating source (〈Q1〉) Meiyu period Yangtze River Basin flood/drought
下载PDF
A SPATIAL-TEMPORAL DISTRIBUTION CHARACTERISTICS STUDY ON THE ATMOSPHERIC CARBON DIOXIDE OBSERVED BY GOSAT SATELLITE REMOTE SENSING 被引量:4
18
作者 刘瑞霞 张兴赢 +1 位作者 刘杰 刘雅各 《Journal of Tropical Meteorology》 SCIE 2015年第4期408-416,共9页
The variation of the atmospheric Carbon Dioxide (CO2) concentration plays an important role in global cli- mate and agriculture. We analyzed the spatial-temporal characteristics of CO2 in the China region and around... The variation of the atmospheric Carbon Dioxide (CO2) concentration plays an important role in global cli- mate and agriculture. We analyzed the spatial-temporal characteristics of CO2 in the China region and around the globe with the CO2 column mixing ratios observed by the Japanese GOSAT satellite (Greenhouse Gases Observing Satellite). In order to make sure that the accuracy of the CO2 data retrieved by the satellite meets the needs of the climate charac- teristics analyses, we ran a validation on the CO2 column mixing ratios retrieved by the satellite against the ground-based TCCON (Total Carbon Column Observing Network) observation data. The result shows that the two sets of data have a correlation coefficient of higher than 0.7, and a bias of within 2.2 ppmv. Therefore, the GOSAT CO2 da- ta can be used for the climate characteristics analysis of global CO2. Our analysis on the spatial-temporal characteristics of the CO2 column mixing ratios observed during the period of June 2009 through January 2014 proved that, with the impact of the natural emission of near ground CO2 and human activities, the global CO2 concentration has a significant latitudinal characteristics with its highest level averaging 390 oomv in the 0-40?N latitudinal zone in the Northern Hemisphere, and 387 ppmv in the Southern Hemisphere. China has a relatively higher CO2 concentration with the highest level exceeding 398 ppmv, and the eastern area higher than the western area. The variation of global CO2 concentration shows a seasonal pattern, i.e. the CO2 concen- tration reaches its highest in spring in the Northern Hemisphere averaging more than 392 ppmv, second highest in win- ter, and lowest in summer averaging less than 387 ppmv. It fluctuates the most in the Northern Hemisphere with an av- erage concentration of 392.5 ppmv in April, and 385.5 ppmv in July. While in the Southern Hemisphere, the seasonal fluctuation is smaller with the highest concentration occurring in July. Over the recent years, the global CO2 concentra- tion has shown an elevating trend with an average annual increase rate of 1.58 ppmv per year. It is a challenge that the human kind has to face to slow down the increase of the CO2 concentration. 展开更多
关键词 GOSAT CO2 spatial-temporal characteristics VALIDATION
下载PDF
HIGH-RESOLUTION NUMERICAL SIMULATION OF TYPHOON LONGWANG(2005) WITH THE SPECTRUM NUDGING TECHNIQUE 被引量:3
19
作者 李静 汤剑平 方娟 《Journal of Tropical Meteorology》 SCIE 2015年第4期311-325,共15页
With the Weather Research and Forecasting model (WRFV3.2.1), the application of specmun nudging tech- niques in numerical simulation of the genesis and development of typhoon Longwang (2005) is evaluated in this w... With the Weather Research and Forecasting model (WRFV3.2.1), the application of specmun nudging tech- niques in numerical simulation of the genesis and development of typhoon Longwang (2005) is evaluated in this work via four numerical experiments with different nudging techniques. It is found that, due to the ability to capture the large-scale fields and to keep the meso-to small-scale features derived from the model dynamics, the experiment with spectrum nudging technique can simulate the formation, intensification and motion of Longwang properly. The improve- ment on the numerical simulation of Longwang induced by the spectrum nudging depends on the nudging coefficients. A weak spectrum nudging does not make significant improvement on the simulation of Longwang. Although the experi- ment with four-dimensional data assimilation, i.e., FDDA, also derives the genesis and movement of Longwang appro- priately, it fails to simulate the intensifying process of Longwang properly. The reason is that, as the large-scale features derived from the model are nudged to the observational data, the meso- to small-processes produced by the model dy- namics important to the intensification of typhoon are nearly smoothed by FDDA. 展开更多
关键词 TYPHOON GENESIS INTENSIFICATION spectrum nudging FDDA
下载PDF
CLIMATOLOGICAL LOW-FREQUENCY OSCILLATION OF OLR OVER THE MARITIME CONTINENT WITH ITS POSSIBLE LINKAGE TO SUMMER PRECIPITATION IN CHINA 被引量:3
20
作者 靳振华 管兆勇 《Journal of Tropical Meteorology》 SCIE 2015年第4期361-373,共13页
Using the 1979-2009 NCEP/NACR reanalysis data and precipitation records in East China, research is performed of the climatological features of low-frequency oscillation(LFO) in OLR over the Maritime Continent(MC) as w... Using the 1979-2009 NCEP/NACR reanalysis data and precipitation records in East China, research is performed of the climatological features of low-frequency oscillation(LFO) in OLR over the Maritime Continent(MC) as well as their associations with precipitation disturbance in the eastern part of China. Results suggest that in the MC there is significant climatological low-frequency oscillation(CLFO) in outgoing long-wave radiation(OLR), with the intraseasonal oscillation(30-60 days) being the strongest for April-September, and the MC acting as a high-value region of percentage contributions of low-frequency OLR variance. On the low-frequency time scale there occur four events of more intense active OLR during this time interval. In the January-April(May-August) phase, MC convection is relatively weak(vigorous). The CLFO makes pronounced eastward displacement at tropics, with phase propagation seen longitudinally, too. There occur low-frequency disturbance circulations similar to the EAP wavetrain or P-J teleconnection,starting from the MC via the South China Sea and the Philippines to the Yangtze valley of China. At different phases,the variation in the low-frequency circulations and heating fields shows that the rainfall disturbance in eastern China is likely to be under possible effects of the CLFO from the MC in April-September, and the low-frequency heating variation exhibits a meridional pattern as an EAP wavetrain or P-J teleconnection. As the OLR CLFO is in a peak(valley)phase the low-level divergence or convergence with the reversal at high levels over the MC is related to relatively feeble(robust) low frequency convection, thereby exciting an EAP or P-J wavetrain from the MC to the Sea of Japan. At the higher levels, the South-Asian high is eastward(westward) of normal due to effects of low-frequency cyclones(anticyclones), resulting in less(more) rainfall in the Jiangnan(areas in the middle and lower reaches of Yangtze and to the south of the river) and Hetao(the Great Bend of Yellow River) areas, and increased(decreased) rainfall in SW China,Qinghai Plateau and Gansu. At the conversion phases, low-frequency convection becomes more active in parts of the MC, consequently exciting low-frequency wavetrain of cyclones-anticyclones-cyclones at low levels, making the South-Asian high southward of the mean, so that strong convergent zones emerge in the upper and middle Yangtze basins and Jilin of NE China, responsible for plentiful precipitation there in sharp contrast to the rainfall over the band between the Yellow and Huaihe Rivers and the Yunnan-Guizhou Plateau. These results help understand in depth the climatological LFO characteristics and the phase-locked feature, thereby further improving our understanding of the causes of rainfall disturbances in different parts of the country. 展开更多
关键词 climatological low-frequency oscillation summer rainfall Maritime Continent OLR China
下载PDF
上一页 1 2 5 下一页 到第
使用帮助 返回顶部