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Study on attribute characterization for reservoir dynamic monitoring by seismic

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Science china Earth Sciences 2008年第S2期51卷 218-225页

作者： CHEN XiaoHong1,3,LI JingYe2,3 & ZHAO Wei4 1 Key Lab of Geophysical Exploration of CNPC,china Petroleum university,Beijing 102249,china 2 Basin & Reservoir research Center,china Petroleum university,Beijing 102249,china 3 State Key laboratory of Petroleum Resource and Prospecting,china university of Petroleum,Beijing 102249,china 4 research Center of CNOOC,Beijing 100027,china 1. Key Lab of Geophysical Exploration of CNPC China Petroleum University Beijing 102249 China 3. State Key laboratory of Petroleum Resource and Prospecting China University of Petroleum Beijing 102249 China 2. Basin & Reservoir research Center China Petroleum University Beijing 102249 China 4. research Center of CNOOC Beijing 100027 China

Study on characterizing reservoir parameters dynamic variations by time-lapse seismic attributes is the theoretical basis for effectively distinguishing reservoir parameters variations and conducting time-lapse seismic interpretation,and it is also a key step for time-lapse seismic application in real oil fields. Based on the rock physical model of unconsolidated sandstone,the different effects of oil saturation and effective pressure variations on seismic P-wave and S-wave velocities are calculated and analyzed. Using numerical simulation on decoupled wave equations,the responses of seismic amplitude with different offsets to reservoir oil saturation variations are analyzed,pre-stack time-lapse seismic attributes differences for oil saturation and effective pressure variations of P-P wave and P-S converted wave are calculated,and time-lapse seismic AVO (Amplitude Versus Offset) response rules of P-P wave and P-S converted wave to effective pressure and oil saturation variations are compared. The theoretical modeling study shows that it is feasible to distinguish different reservoir parameters dynamic variations by pre-stack time-lapse seismic information,including pre-stack time-lapse seismic attributes and AVO information,which has great potential in improving time-lapse seismic interpreta-tion precision. It also shows that the time-lapse seismic response mechanism study on objective oil fields is especially important in establishing effective time-lapse seismic data process and interpreta-tion scheme.

关键词： time-lapse seismic dynamic monitoring rock physical model pre-stack attribute Amplitude Versus Offset (AVO)

EFFECTS OF SUBMERGED MACROPHYTES ON SEDIMENT SUSPENSION AND NH_4-N RELEASE UNDER HYDRODYNAMIC CONDITIONS

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Journal of Hydrodynamics 2010年第6期22卷 810-815页

作者： WANG Chao WANG Cun WANG Ze Key laboratory of Integrated Regulation and Resource Department on Shallow Lakes Ministry of EducationHohai University Nanjing 210098 China State Key laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing210098 China College of Mechanics and Materials Hohai University Nanjing 210098 China

Aquatic vegetation affects sediment suspension and nutrient release by changing the flow structure. Experiments on the influence of submerged vegetation on flow structure, sediment suspension, and NH4-N release were carried in a flume with natural submerged vegetation. Turbulence characteristics in the vegetation section were measured using a three-dimensional acoustic Doppler velocimeter. The effects of submerged vegetation on bed shear stress （ τb ）, sediment suspension, and NH4-N release were analyzed. Results show that with vegetation, bed shear stress is reduced by about 20% - 80%, which, in turn, reduces sediment suspension. The impact of submerged vegetation on sediment suspension and NH4-N release should be considered along with flow intensity. When the flow Reynolds number is relatively small, the submerged vegetation is quite capable of inhibiting sediment suspension and reducing NH4-N release, but when the Reynolds number reaches a certain value, the presence of aquatic plants exacerbates sediment suspension and promotes NH4-N release. Results also reveal that a highly significant positive correlation exists between NH4-N concentration and water turbidity in both vegetated and non-vegetated channels.

关键词： sediment suspension submerged macrophytes turbulence behavior bed shear stress turbidity

PERFORMANCE OF LDPC CODED FMT SYSTEMS OVER FREQUENCY SELECTIVE FADING CHANNEL

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Journal of Electronics(china) 2005年第6期22卷 575-580页

作者： Li Qiang Bi Guangguo Du Peng national mobile communications research Lab Southeast University Nanjing 210096 China

This paper proposes the Low Density Parity Check (LDPC) coded Filtered MultiTone (FMT) systems with high-order modulation for the high data rate reliable transmission over frequency selective fading channel. For the purpose of accomplishing soft input soft output iterative decoding of LDPC codes, a new soft decision metric generation method is proposed,which obviates the need of the noise variance estimation, for M-PSK/M-QAM-type high-order modulation over frequency selective fading channel. Computer simulation indicates that, there is no performance loss with our new metric, but the complexity of implementation is reduced, and that the LDPC codes are effective to improve the Bit Error Rate (BER) of FMT in frequency selective fading channel.

关键词： Low Density Parity Check (LDPC) code Filtered MultiTone (FMT) Frequency-selective fading channel

The Construction of Numerical Scheme forHyperbolic Equation and Exact Considerationof Numerical Diffusion and Dispersion

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communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 156-162页

作者： Qingdong CAI(State Key laboratory for Turbulence research, Peking university, Beijing 100871, china) State Key laboratory for Turbulence research Peking University Beijing 100871 China

A new technique in the formulation of numerical scheme for hyperbolicequation is developed. It is different from the classical FD and FE methods. We begin withthe algebraic equations with some undefined parameters, and get the difference equationthrough Taylor-series expansion. When the parameters in the partial difference equationare defined, the equation is what the scheme will simulate. The numerical example ofthe viscous Burgers equation shows the validity of the scheme. This method deals withthe numerical viscosity and dispersion exactly, giving a preliminary explanation to someproblems that the CFD face now.

关键词： modified equation Taylor expansion consistency truncation error

A self-steering close-talking microphone array

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Progress in Natural Science:Materials International 2005年第11期15卷 1044-1049页

作者： PENG Ke, YANG Xinfeng and XU Boling (State Key laboratory of Modern Acoustics, Institute of Acoustics, nanjing university, nanjing 210093, china) State Key laboratory of Modern Acoustics Institute of Acoustics Nanjing University Nanjing 210093 China

For communication in extremely noisy environments, close-talking microphone arrays are useful. Differential microphone array systems possessing excellent nearfield directivity and strong farfield-noise reduction capability are very suitable for close-talking situations. In order to improve the focusing effect at the desired bearing in the nearfield, we propose a novel self-steering system of close-talking arrays with the first-order differential sub-arrays in this paper. Calculations of directivity patterns and directivity factors show that when a kind of optimized beamforming technique is adopted even small arrays with a focusing configuration will exhibit a satisfactory nearfield directivity which is electronically steerable within a specific range. The superiority of the proposed array system is verified by experiments with real acoustic data.

关键词： close-talking array differential array self-steering directivity factor.

Confirmation of combinational effects of calcium with other metals in a paper recycling mill effluent on nematode lifespan with toxicity identification evaluation method

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Journal of Environmental Sciences 2010年第5期22卷 731-737页

作者： Dayong Wang,Yang Wang,Lulu Shen Key laboratory of Developmental Genes and Human Disease in Ministry of Education,Department of Genetics and Developmental Biology,southeast university Medical School,nanjing 210009,china. [a] Key laboratory of Developmental Genes Human Disease in Ministry of Education Department of Genetics Developmental Biology Southeast University Medical School Nanjing 210009 China

We used toxicity identification evaluation （TIE） method to confirm the combinational effects of identified toxic metals in a paper recycling mill effluent in inducing the decreased lifespan in nematode Caenorhabditis *** to Ca ＋ Al caused more severely decreased lifespan than that exposed to Ca,or Al;and exposure to Ca ＋ Fe induced more severely decreased lifespan than that exposed to Ca,or *** to Ca＋Al＋Fe caused more severely decreased lifespan than that exposed to Ca,or Ca＋***,the baseline toxicity on lifespan was doubled by doubling the concentration of combined metals （Ca＋Al＋Fe） in spiking test in original effluent （oe）,and lifespan defects in oe＋Ca＋Al＋Fe exposed nematodes were more severe than that in Ca＋Al＋Fe exposed ***,Ca＋Al＋Fe exposure may largely explain the formation of decreased lifespan induced by the examined industrial ***,the observed reduction of lifespan induced by the combination of high level of Ca with other metals may be at least partially independent of the insulin-like pathway.

关键词： lifespan calcium combinational toxicity toxicity identification evaluation (TIE) Caenorhabditis elegans

Identification of genomic regions determining flower and pod numbers development in soybean (Glycine max L.)

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Journal of Genetics and Genomics 2010年第8期37卷 545-556页

作者： Dan Zhang, Hao Cheng, Hui Wang, Hengyou Zhang, Chunying Liu, Deyue Yu national Center for Soybean Improvement, national Key laboratory of Crop Genetics and Germplasm Enhancement, nanjing Agricultural university, nanjing 210095, china [a] national Center for Soybean Improvement National Key Laboratory of Crop Genetics and Germplasm Enhancement Nanjing Agricultural University Nanjing 210095 China

Flower and pod numbers per plant are important agronomic traits underlying soybean yield. So far quantitative trait loci （QTL） de- tected for flower and pod-related traits have mainly focused on the final stage, and might therefore have ignored genetic effects expressed during a specific developmental stage. Here, dynamic expressions of QTL for flower and pod numbers were identified using 152 recom- binant inbred lines （RILs） and a linkage map of 306 markers. Wide genetic variation was found among RILs; 17 unconditional and 18 conditional QTL were detected for the two traits at different developmental stages over two years. Some QTL were detected only at one stage and others across two or more stages, indicating that soybean flower and pod numbers development may be governed by time-dependent gene expression. Three main QTL （qfn-Chrl8-2, qfn-Chr20-1, and qfn-Chr19） were detected for flower number, and two main QTL （qpn-Chrll and qpn-Chr20） were detected for pod number. The phenotypic variation explained by them ranged from 6.1% to 34.7%. The markers linked to these QTL could be used in marker-assisted selection for increasing soybean flower and pod numbers, with the ultimate aim of increasing soybean yield. Comparison of the QTL regions for flower and pod numbers traits with the related genes reported previously showed that seven and four related genes were located in the QTL regions of qfn-Chr11 and qfn-Chr19, respectively. These results provide a basis for free mapping and cloning of flower and pod development-related genes.

关键词： conditional QTL unconditional QTL developmental quantitative genetics flower number pod number soybean

Constructing G^2 Continuous Curve on Freeform Surface with Normal Projection

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Chinese Journal of Aeronautics 2010年第1期23卷 137-144页

作者： Wang Xiaoping,An Luling,Zhou Laishui,Zhang Liyan Jiangsu Key laboratory of Precision and Macro-manufacturing Technology,nanjing university of Aeronautics and Astronautics,nanjing 210016,china [a] Jiangsu Key laboratory of Precision Macro-manufacturing Technology Nanjing University of Aeronautics Astronautics Nanjing 210016 China

This article presents a new method for G2 continuous interpolation of an arbitrary sequence of points on an implicit or parametric surfaee with prescribed tangent direction and curvature vector, respectively, at every point. First, a G2 continuous curve is constructed in three-dimensional space. Then the curve is projected normally onto the given surface. The desired interpolation curve is just the projection curve, which can be obtained by numerieally solving the initialvalue problems for a system of first-order ordinary differential equations in the parametric domain for parametric case or in three-dimensional space for implicit ease. Several shape parameters are introduced into the resulting curve, which can be used in subsequent interactive modification so that the shape of the resulting curve meets our demand. The presented method is independent of the geometry and parameterization of the base surface. Numerical experiments demonstrate that it is effective and potentially useful in numerical control （NC） machining, path planning for robotic fibre placement, patterns design on surface and other industrial and research fields.

关键词： Hermite interpolation normal projection freeform surface G2 continuity ordinary differential equations

Isotope Method for Confined Groundwater Recharge of the Lower Reaches of the Heihe River,Inner Mongolia,china

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Acta Geologica Sinica(English Edition) 2007年第4期81卷 668-673页

作者： CHEN Jiansheng ZHAO Xia FAN Zhechao and WANG Jiyang 1 State Key laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai university,nanjing 210098,china 2 Institute of Isotope Hydrology research,Hohai university,nanjing 210098,china 3 Institute of Geology and Geophysics,Chinese Academy of Science,Beijing 100018,china State Key laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China

Environmental isotopes have been appfied to analyze confined groundwater recharge in the lower reaches of the Heihe River, Inner Mongolia. CFC is regarded as a tracer that determines the date of groundwater, the date being less than 45 a. The confined groundwater within the Gurinai area and Ejin Basin other than the surface water of Heihe River might have originated from precipitation from Qilian Mountain or/and the Tibetan Plateau. The deep confined groundwater overflows into an upper aquifer and emerges into the ground, forming springs and lakes within the low-lying area. The recharge volume is estimated to be around 400 million-cubic meters.

关键词： isotope CFC Ejin Basin Gurinai groundwater recharge precipitation Qilian Mountain