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3D numerical simulation of boreholes for gas drainage based on the pore–fracture dual media

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International Journal of Mining Science and Technology 2016年第4期26卷 739-744页

作者： Wei jianping li Bo Wang Kai Sun Donghui State Key Laboratory Cultivation Base Henan Province Key Laboratory of Gas Geology and Gas Control Henan Polytechnic University Jiaozuo 454003 China Collaborative Innovation Center of Coal Safety Production of Henan Province Jiaozuo 454003 China Henan Province Key Laboratory of Biogenic Traces and Sedimentary Minerals Henan Polytechnic University Jiaozuo 454003 China School of Resources and Safety Engineering China University of Mining and Technology Beijing 100083 China

A gas migration controlling equation was formulated based on the characteristics of the dual pore–fracture media of coal mass and in consideration of the matrix exchange between pores and fractures.A model of permeability dynamic evolution was established by analyzing the variation in effective stress during gas drainage and the action mechanism of the effect of coal matrix desorption on porosity and fracture in the coal body.A coupling model can then be obtained to characterize gas compressibility and coal deformability under the gas–solid coupling of loading *** addition,a 3D model of boreholes was established and solved for gas drainage based on the relevant physical parameters of real *** comparison and analysis results for the law of gas migration and the evolution of coal body permeability around the boreholes before and after gas extraction between the dual media and the single-seepage field models can provide a theoretical basis for further research on the action mechanism of gas drainage.

关键词： Pore-fracture Matrix exchange Coupling model Numerical simulation Gas drainage

Comparison of Nonlinear Local Lyapunov Vectors with Bred Vectors, Random Perturbations and Ensemble Transform Kalman Filter Strategies in a Barotropic Model

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Advances in Atmospheric Sciences 2016年第9期33卷 1036-1046页

作者： Jie FENG Ruiqiang DING jianping li Deqiang liU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 College of Earth Science University of Chinese Academy of SciencesBeijing 100049 Global Systems Division Earth System Research Laboratory/Oceanic and Atmospheric Research/National Oceanic and Atmospheric AdministrationBoulderCO80305USA Plateau Atmosphere and Environment Key Laboratory of Sichuan Province Chengdu University of Information TechnologyChengdu 610225 College of Global Change and Earth System Sciences Beijing Normal UniversityBeijing 100875 Joint Center for Global Change Studies Beijing 100875 Fujian Meteorological Observatory Fuzhou 350001

The breeding method has been widely used to generate ensemble perturbations in ensemble forecasting due to its simple concept and low computational cost. This method produces the fastest growing perturbation modes to catch the growing components in analysis errors. However, the bred vectors （BVs） are evolved on the same dynamical flow, which may increase the dependence of perturbations. In contrast, the nonlinear local Lyapunov vector （NLLV） scheme generates flow-dependent perturbations as in the breeding method, but regularly conducts the Gram-Schmidt reorthonormalization processes on the perturbations. The resulting NLLVs span the fast-growing perturbation subspace efficiently, and thus may grasp more com- ponents in analysis errors than the BVs. In this paper, the NLLVs are employed to generate initial ensemble perturbations in a barotropic quasi-geostrophic model. The performances of the ensemble forecasts of the NLLV method are systematically compared to those of the random pertur- bation （RP） technique, and the BV method, as well as its improved version--the ensemble transform Kalman filter （ETKF） method. The results demonstrate that the RP technique has the worst performance in ensemble forecasts, which indicates the importance of a flow-dependent initialization scheme. The ensemble perturbation subspaces of the NLLV and ETKF methods are preliminarily shown to catch similar components of analysis errors, which exceed that of the BVs. However, the NLLV scheme demonstrates slightly higher ensemble forecast skill than the ETKF scheme. In addition, the NLLV scheme involves a significantly simpler algorithm and less computation time than the ETKF method, and both demonstrate better ensemble forecast skill than the BV scheme.

关键词： ensemble forecasting bred vector nonlinear local Lyapunov vector ensemble transform Kalman filter

Geochemical characteristics and source analysis of inflow of mine water in Wang’ershan Gold Mine, Shandong

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Chinese Journal Of Geochemistry 2008年第1期27卷 82-89页

作者： QIAN jianping li Shuangli CAO Chao Guilin University of Technology Guilin 541004 China

Through a systematic observation of water level and temperature, and a comprehensive analysis of the data on major/trace elements, nitrite, hydrogen-oxygen isotopes, the conclusion has been drawn that there are two relatively independent groundwater systems (cool water and hot water), and the geochemical indicators of hot/cool waters are described. The cool water system is relatively enriched in Ca2+, Mg2+ and HCO3-. Its TDS is relatively low, about 1400–1800 mg/L. The hot water system is relatively enriched in K+, Na+, Cl- and SO42-. Its TDS is relatively high, about 2200–2300 mg/L. The cool water system is enriched in Ba, Ga, Cd, and the hot water system is enriched in B, Ti, Cr, Ni, Cu, Mo, Rb, and Cs, relatively. Especially, the contents of Rb and Cs in the hot water system are more than five times as high as those in the cool water system. The NO3- contents of cool water discharged from the gold mine are relatively high, and those of hot water are extremely low. The δD and δ18O values follow an increasing order of surface water>mine cool water>mine hot water. The cool water comes mainly from the lateral supply of phreatic water, while the hot water comes mainly from the vertical supply of deeply circulating structure-fracture water. The ratio of cool water over hot water was estimated to be about 1:1 by a water quality model..

关键词：地理特征分析方法矿山地下水

Predictability of Ensemble Forecasting Estimated Using the Kullback–Leibler Divergence in the Lorenz Model

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Advances in Atmospheric Sciences 2019年第8期36卷 837-846页

作者： Ruiqiang DING Baojia liU Bin GU jianping li Xuan li State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth Sciences University of Chinese Academy of SciencesBeijing 100049China Institute of Space Weather School of Math and StatisticsNanjing University of Information Science and TechnologyNanjing 210044China College of Physics and Optoelectronic Engineering Nanjing University of Information Science and TechnologyNanjing 210044China College of Global Change and Earth System Sciences Beijing Normal UniversityBeijing 100875China

A new method to quantify the predictability limit of ensemble forecasting is presented using the Kullback–Leibler(KL)divergence(also called the relative entropy), which provides a measure of the difference between the probability distributions of ensemble forecasts and local reference(true) states. The KL divergence is applicable to a non-normal distribution of ensemble forecasts, which is a substantial improvement over the previous method using the ensemble spread. An example from the three-variable Lorenz model illustrates the effectiveness of the KL divergence, which can effectively quantify the predictability limit of ensemble forecasting. On this basis, the KL divergence is used to investigate the dependence of the predictability limit of ensemble forecasting on the initial states and the magnitude of initial errors. The local predictability limit of ensemble forecasting varies considerably with the initial states, as well as with the magnitude of initial errors. Further research is needed to examine the real-world applications of the KL divergence in measuring the predictability of ensemble weather forecasts.

关键词： predictability ensemble forecasting Kullback–Leibler divergence

Atmospheric Warming Slowdown during 1998-2013 Associated with Increasing Ocean Heat Content

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Advances in Atmospheric Sciences 2019年第11期36卷 1188-1202,I0006,I0007,I0008,I0009,I0010,I0011页

作者： Changyu li jianping HUANG Yongli HE Dongdong li Lei DING Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou University

Although atmospheric greenhouse gas concentrations continuously increased, there was relatively little change in global-averaged surface temperatures from 1998 to 2013, which is known as atmospheric warming slowdown. For further understanding the mechanism involved, we explored the energy redistribution between the atmosphere and ocean in different latitudes and depths by using data analysis as well as simulations of a coupled atmosphere–ocean box model. The results revealed that, compared with observational changes of ocean heat content (OHC) associated with rapid warming, the OHC changes related to warming slowdown are relatively larger in multiple ocean basins, particularly in the deeper layer of the Atlantic. The coupled box model also showed that there is a larger increasing trend of OHC under the warming slowdown scenario than the rapid warming scenario. Particularly, during the warming slowdown period, the heat storage in the deeper ocean increases faster than the ocean heat uptake in the surface ocean. The simulations indicated that the warming patterns under the two scenarios are accompanied by distinct outgoing longwave radiation and atmospheric meridional heat transport, as well as other related processes, thus leading to different characteristics of ocean heat uptake. Due to the global energy balance, we suggest this slowdown has a tight relationship with the accelerated heat transport into the global ocean.

关键词： warming slowdown ocean heat content box model heat transport

Supply of terrigenous organic matter from tidal flat to the marine environment:An example of neritic source rocks in the Eocene Pinghu Formation,Xihu Depression,East China Sea Shelf Basin

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Acta Oceanologica Sinica 2023年第3期42卷 138-150页

作者： Shanshan Zhou Youchuan li jianping li Wenjing Ding Xin li Weilai Zhang China National Offshore Oil Corporation(CNOOC)Research Institute Co. Ltd.Beijing 100028China School of Chemical Engineering and Environment China University of Petroleum(Beijing)Beijing 102200China

The terrigenously-dominated marine shales which were deposited in the lower Eocene Pinghu Formation were thought to be a potential source rock in the Xihu Depression of the East China Sea Shelf ***,the exceptionally high total organic carbon content(TOC,>6%on average)of the tidal sand ridge samples was not compatible with their sedimentary environment,indicating coal-bearing sedimentary debris may have been transferred from the coast to the *** this study,new sights into the origins and supply of organic materials in the coastal environment were proposed in the neritic organic matter of the Eocene Pinghu Formation.A discriminant model was developed using plynofacies analysis data to pinpoint the source of organic materials in marine source *** discrimination results suggested that marine mudstones were associated with tidal flat mudstones rather than deltaic *** biomarker characteristics of mudstones deposited in various environments support this assertion,indicating that the supply of plant materials in tidal flats is the primary organic matter source for the marine *** organic matter abundance was elevated in tidal flats due to their superior preservation ***,the lithological assemblage of tidal flats suggests that tidal currents can scour marshes and then transport dispersed terrigenous organic materials to neritic *** findings indicate that coal-bearing sedimentary debris was likely transferred from the coast to the ocean,and tidal currents are thought to be the dominant mechanism driving organic matter from the tidal to the marine environment.

关键词： terrestrial organic matter neritic source rocks palynofacies analysis discriminant analysis

Modulation of the Intensity of Nascent Tibetan Plateau Vortices by Atmospheric Quasi-Biweekly Oscillation

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Advances in Atmospheric Sciences 2018年第11期35卷 1347-1361页

作者： Lun li Renhe ZHANG Min WEN jianping DUAN State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Atmospheric Sciences Fudan UniversityShanghai 200433China Chinese Academy Science Center for Excellence in Tibetan Plateau Earth Sciences Beijing 100101China Institute of Atmospheric Physics Chinese Academy ScienceBeijing 100029China

The modulation of the intensity of nascent Tibetan Plateau vortices(ITPV) by atmospheric quasi-biweekly oscillation(QBWO) is investigated based on final operational global analysis data from the National Centers for Environmental Prediction. The spatial and temporal distributions of the ITPV show distinct features of 10–20-day QBWO. The average ITPV is much higher in the positive phases than in the negative phases, and the number of strong TPVs is much larger in the former,with a peak that appears in phase 3. In addition, the maximum centers of the ITPV stretch eastward in the positive phases,indicating periodic variations in the locations where strong TPVs are generated. The large-scale circulations and related thermodynamic fields are discussed to investigate the mechanism by which the 10–20-day QBWO modulates the ITPV. The atmospheric circulations and heating fields of the 10–20-day QBWO have a major impact on the ITPV. In the positive QBWO phases, the anomalous convergence at 500 hPa and divergence at 200 hPa are conducive to ascending motion. In addition, the convergence centers of the water vapor and the atmospheric unstable stratification are found in the positive QBWO phases and move eastward. Correspondingly, condensational latent heat is released and shifts eastward with the heating centers located at 400 hPa, which favors a higher ITPV by depressing the isobaric surface at 500 hPa. All of the dynamic and thermodynamic conditions in the positive QBWO phases are conducive to the generation of stronger TPVs and their eastward expansion.

关键词： quasi-biweekly oscillation Tibetan Plateau vortex modulation

Dryland Expansion in Northern China from 1948 to 2008

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Advances in Atmospheric Sciences 2015年第6期32卷 870-876页

作者： li Yue HUANG jianping JI Mingxia RAN Jinjiang Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric Sciences Lanzhou University

This study examines the expansion of drylands and regional climate change in northern China by analyzing the variations in aridity index （AI）, surface air temperature （SAT）, precipitation and potential evapotranspiration （PET） from 1948 to 2008. It is found that the drylands of northern China have expanded remarkably in the last 61 years. The area of drylands of the last 15 years （1994--2008） is 0.65 × 106 km2 （12%） larger than that in the period 1948-62. The boundary of drylands has extended eastward over Northeast China by about 2 °of longitude and by about 1° of latitude to the south along the middle- to-lower reaches of the Yellow River. A zonal band of expansion of semi-arid regions has occurred, stretching from western Heilongjiang Province to southern Gansu Province, while shifts to the east of semi-arid regions in dry subhumid regions have also occurred. Results show that the aridity trend of drylands in northern China is highly correlated with the long-term trend of precipitation and PET, and the expansion of semi-arid regions plays a dominant role in the areal extent of drylands, which is nearly 10 times larger than that in arid and subhumid regions.

关键词： aridity index dryland expansion climate variation northern China

Genetic association of urokinase-type plasminogen activator gene rs2227564 site polymorphism with sporadic Alzheimer's disease in the Han Chinese population

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Neural Regeneration Research 2012年第30期7卷 2377-2383页

作者： Xuelian Ji Longfei Jia jianping Jia li Qi Department of Neurology Inner Mongolia People's Hospital Huhhot 010017 Inner Mongolia Autonomous Region China Department of Neurology Xuanwu Hospital Capital Medical University Beijing 100053 China Inner Mongolia Corps Hospital Chinese People's Armed Police Forces Huhhot 010040 Inner Mongolia Autonomous Region China

A missense C/T polymorphism in exon 6 （the NCBI rslD is rs2227564） of the urokinase-type plasminogen activator gene has been identified as a possible hot spot for Alzheimer＇s disease risk. The present study analyzed urokinase-type plasminogen gene polymorphisms of rs2227564 with sporadic Alzheimer＇s disease by PCR-restriction fragment length polymorphism. Results showed that CC, CT and TT genotype distribution frequencies had significant differences between sporadic Aizheimer＇s disease patients and healthy controls, in-depth analysis of the association between urokinase-type plasminogen gene rs2227564 polymorphisms and sporadic Alzheimer＇s disease indicated that people with the C-positive genotype CC ＋ CT were at a higher risk for developing sporadic Alzheimer＇s disease. These results support the contribution of the polymorphisms of rs2227564 in the urokinase-type plasminogen gene to the pathogenesis of sporadicAIzheimer＇s disease in the Han Chinese population.

关键词： Alzheimer's disease urokinase plasminogen activator polymorphism genetic testing Han Chinesepopulation neural regeneration