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Dynamic attack zone of air-to-air missile after being launched in random wind field

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Chinese Journal of Aeronautics 2015年第5期28卷 1519-1528页

作者： Hui Yaoluo nan ying Chen Shaodong Ding Quanxin Wu Shengliang College of Astronautics Nanjing University of Aeronautics and Astronautics Science and Technology on Electro-optic Control Laboratory

A new concept is presented for air-to-air missile which is dynamic attack zone after being launched in random wind field. This new concept can be used to obtain the 4-dimensional （4-D） information regarding the dynamic envelope of an air-to-air missile at any flight time airned at different flight targets considering influences of random wind, in the situation of flight fighters coop- crated with missiles fighting against each other. Based on an air-to-air missile model, some typical cases of dynamic attack zone after being launched in random wind field were numerically simulated. Compared with the simulation results of traditional dynamic envelope, the properties of dynamic attack zone after being launched are as follows. The 4-D dynamic attack zone after being launched is inside traditional maximum dynamic envelope, but its forane boundary is usually not inside traditional no-escape dynamic envelope; Traditional dynamic attack zone can just be reliably used at launch time, while dynamic envelope after being launched can be reliably and accurately used during any flight antagonism time. Traditional envelope is a special case of dynamic envelope after being launched when the dynamic envelope is calculated at the launch time： the dynamic envelope after being launched can be inflt, enced by the random wind field.

关键词： Air-to-air missiles Dynamic attack zone afterbeing launched:Traditional dynamic attackenvelope:Flight dynamics:Flight envelopes Numerical calculationprocedures:Simulation analysis

Spatial patterns of net primary productivity and its driving forces:a multi-scale analysis in the transnational area of the Tumen River

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Frontiers of Earth Science 2020年第1期14卷 124-139页

作者： Jianwen WANG Da ZHANG ying nan Zhifeng LIU Dekang QI Department of Geography Yanbian UniversityYanji 133002China Center for Human-Environment System Sustainability(CHESS) State Key Laboratory of Earth Surface Processes and Resource Ecology(ESPRE)Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China School of Natural Resources Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Analyzing the spatial patterns of net primary productivity(NPP)and its driving forces in transnational areas provides a solid basis for understanding regional ecological processes and ecosystem ***,the spatial patterns of NPP and its driving forces have been poorly understood on multiple scales in transnational *** this study,the spatial patterns of NPP in the transnational area of the Tumen River(TATR)in 2016 were simulated using the Carnegie Ames Stanford Approach(CASA)model,and its driving forces were analyzed using a stepwise multiple linear regression *** found that the total amount of NPP in the TATR in 2016 was approximately 14.53 *** amount of NPP on the Chinese side(6.23 TgC)was larger than those on the other two sides,accounting for 42.88%of the total volume of the entire *** different land-use and land-cover(LULC)types,the amount of NPP of the broadleaf forest was the largest(11.22 TgC),while the amount of NPP of the bare land was the *** NPP per unit area was about 603.21 gC/(m2 yr)across the entire region,while the NPP per unit area on the Chinese side was the largest,followed by the Russian side and the DPRK's *** spatial patterns of NPP were influenced by climate,topography,soil texture,and human *** addition,the driving forces of the spatial patterns of NPP in the TATR had an obvious scaling effect,which was mainly caused by the spatial heterogeneity of climate,topography,soil texture,and human *** suggest that effective land management policies with cooperation among China,the DPRK,and Russia are needed to maintain NPP and improve environmental sustainability in the TATR.

关键词： transnational area of the Tumen River NPP spatial pattern driving force multiple scale

NUMERICAL SIMULATION OF GAS TURBULENCE ENHANCEMENT BY PARTICLE-WAKE EFFECT

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Journal of Hydrodynamics 2007年第2期19卷 155-159页

作者： ZENG Zhuo-zhi ZENG Zhuo-xiong nan ying HAN Shou-lei Aeronautic and Mechanical Engineering college Nanchang University of Aeronautics Nanchang 330063 China

A new turbulence enhancement model was incorporated into the second-order moment two-phase turbulence model and was used to simulate gas-particle flows in swirling chambers and channels with different wall roughness. The results show that compared with the turbulence modification model not accounting for the wake effect, this model, together with the conventional particle source term, gives simulation results in better agreement with the experimental data.

关键词： gas-particle flows turbulencemodification numerical simulation

Compute extremely low-frequency electromagnetic field exposure by 3-D impendance method

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The Journal of China Universities of Posts and Telecommunications 2007年第3期14卷 113-116页

作者： HAN Yu-nan LV ying-hua ZHANG Hong-xin Beijing University of Posts and Telecommunications Beijing 100876 ChinaAerospace Science and Technology Group Beijng 100076 China

A 3-D impedance method has been introduced to compute the electric currents induced in a human body exposed to extremely low-frequency electromagnetic field. The 3-D impedance method has been deduced from Maxwell equations and is put into the computation and simulation effectively to the visible human body model, which has 196×114×626 cells and more than 40 types of tissues. As the result, two representative cases are investigated. One is exposure of the human body to 100 μT （1 000 mG）, the limit recommended by the International Commission on Non-Ionizing Radiation Protection for the public and the other one is the exposure of human body to 0.4 laT （4 mG）, the level at which a statistical link appears with a doubled risk of development of childhood leukaemia. The distribution of induced current density can be obtained and the maximum of induced current are found to be 16 mA/m^2 and 0.07 mA/m^2.

关键词： 3-D impedance method induced current magnetic flux density visible human body model extremely low frequency (ELF)

Simultaneous denoising and resolution enhancement of seismic data based on elastic convolution dictionary learning

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Petroleum Science 2023年第4期20卷 2127-2140页

作者： nan-ying Lan Fan-Chang Zhang Kai-Heng Sang Xing-Yao Yin School of Geosciences China University of Petroleum(East China)QingdaoShandong266580China

Enhancing seismic resolution is a key component in seismic data processing, which plays a valuable role in raising the prospecting accuracy of oil reservoirs. However, in noisy situations, existing resolution enhancement methods are difficult to yield satisfactory processing outcomes for reservoir characterization. To solve this problem, we develop a new approach for simultaneous denoising and resolution enhancement of seismic data based on convolution dictionary learning. First, an elastic convolution dictionary learning algorithm is presented to efficiently learn a convolution dictionary with stronger representation capability from the noisy data to be processed. Specifically, the algorithm introduces the elastic L1/2 norm as a sparsity constraint and employs a steepest gradient descent strategy to efficiently solve the frequency-domain linear system with substantial computational cost in a half-quadratic splitting framework. Then, based on the learned convolution dictionary, a weighted convolutional sparse representation paradigm is designed to encode the noisy data to acquire an optimal sparse approximation of the effective signal. Subsequently, a high-resolution dictionary with a broadband spectrum is constructed by the proposed parameter scaling strategy and matched filtering technique on the basis of atomic spectrum modeling. Finally, the optimal sparse approximation of the effective signal and the constructed high-resolution dictionary are used for data reconstruction to obtain the seismic signal with high resolution and high signal-to-noise ratio. Synthetic and field dataset examples are executed to check the effectiveness and reliability of the developed method. The results indicate that this method has a more competitive performance in seismic applications compared with the conventional deconvolution and spectral whitening methods.

关键词： Simultaneous denoising and resolution enhancement Elastic convolution dictionary learning Weighted convolutional sparse representation Matched filtering

Productivity analysis of a fractured horizontal well in a shale gas reservoir based on discrete fracture network model

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Journal of Hydrodynamics 2019年第3期31卷 552-561页

作者： Yu-long Zhao nan-ying Li Lie-hui Zhang Rui-han Zhang State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 China Southwest Oil and Gas Branch SINOPEC Chengdu 610041 China

The treatment of horizontal wells with massive hydraulic fracturing technology is important for the economical development of shale gas reservoirs, but sometimes is complex because of the induced fractures during the fracturing process. The studies of the fluid flow characteristics in such formations are rare. In this study, a numerical method based on a finite element method (FEM) is developed for the productivity analysis of a horizontal well in a shale gas reservoir with complex fractures. The proposed method takes into account the adsorbed gas and the complex hydraulic fracture branches. To make the problem more tractable, the dimension of the fracture system is reduced from 2-D to 1-D based on the discrete fracture network (DFN) model. The accuracy of the new method is verified by comparing its results with those obtained by the Saphir commercial software. Finally, the productivity of the fractured horizontal wells in shale gas reservoirs with complex fractures systems is evaluated and analyzed. Results show that if a well is produced with a constant bottomhole pressure, the well productivity is much increased due to the existence of fracture branches that can increase the stimulated reservoir volume (SRV). In addition, the number of hydraulic fractures (Nf) and the fracture halMengths (Lf) have an important influence on the well's productivity. The larger the values of Nf,Lf,the greater the well productivity will be. The existence of adsorbed gas can markedly improve the well productivity, and the greater the Langmuir volume, the greater the productivity will be. The conclusions drawn by this study can provide a guidance for the development of unconventional shale gas reservoirs.

关键词： Fractured horizontal well discrete fracture network (DFN) model finite element method (FEM) productivity analysis shale gas reservoir

Highly Selective Diphoshinoamine/Cr(III) Catalysts for Ethylene Tetramerization

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Chinese Chemical Letters 2006年第3期17卷 358-360页

作者： Tao JIANG Hong Xia CHEN ying nan NING Wei CHEN School of Chemistry ＆ Chemical Daqing Petroleum Institute Daqing 163318 SINOPEC Beijing Research Institute of Chemical Industry Beijing 100013

Two novel diphoshinoamine ligands have been synthesized. Combination of Cr（Ⅲ） and methylaluminoxane（MAO） generated active catalytic system which can catalyze tetramerization of ethylene with high catalytic activi... 详细信息

关键词： Ethylene tetramerization 1-octene Cr(Ⅲ) diphoshinoamine MAO catalyst

Spatial Patterns of LULC and Driving Forces in the Transnational Area of Tumen River:A Comparative Analysis of the Sub-regions of China,the DPRK,and Russia

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Chinese Geographical Science 2020年第4期30卷 588-599页

作者： nan ying WANG Bingbing ZHANG Da LIU Zhifeng QI Dekang ZHOU Haohao College of Geography and Ocean Sciences Yanbian UniversityYanji Jilin133002China Center for Human-Environment System Sustainability(CHESS) State Key Laboratory of Earth Surface Processes and Resource Ecology(ESPRE)Beijing Normal UniversityBeijing 100875China School of Natural Resources Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China

Understanding the spatial patterns of land-use and land-cover(LULC)and their driving forces in transnational areas is important for the sustainable development of these ***,the spatial patterns of LULC and their driving forces across multiple scales are poorly understood in transnational *** this study,we analyzed the spatial patterns of LULC and driving forces in the transnational area of Tumen River(TATR)in 2016 across two scales:the entire region and the sub-regions of China,the Democratic People’s Republic of Korea(DPRK),and *** showed that the LULC was dominated by broadleaf forest and dry farmland in the TATR in 2016,which accounted for 66.86%and 13.60%of the entire region,***,the LULC in the three sub-regions exhibited noticeable *** the Chinese and the DPRK’s sub-regions,the area of broadleaf forest was greater than those for the other LULC types,while the Russian sub-region was dominated by broadleaf forest and *** spatial patterns of LULC were mainly influenced by topography,climate,soil properties,and human *** addition,the driving forces of the spatial patterns of LULC in the TATR had an obvious scaling ***,we suggest that effective policies and regulations with cooperation among China,the DPRK,and Russia are needed to plan the spatial patterns of LULC and improve the sustainable development of the TATR.

关键词： land-use and land-cover(LULC) spatial pattern driving force transnational area of Tumen River

Theoretical Interpretation of Conformation Variations of Polydimethylsiloxane Induced by nanoparticles

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Chinese Journal of Polymer Science 2018年第4期36卷 505-513页

作者： Zhao-Yang Wei nan-ying Ning Ming Tian Li-Qun Zhang Jian-Guo Mi State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical Technology Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology

There has been controversy as to whether the addition of nanoparticles to a polymer melt causes perturbed chain structure of polymers. In this work, the chain conformations of polydimethylsiloxane（PDMS） with addition of polyhedral oligomeric silsesquioxane（POSS） nanoparticles have been studied using a classical density functional approach. Under the strong interactions of POSS-PDMS, the radius of gyration of PDMS in the nanocomposites can either increase or decline depending on particle loading. After adding nanoparticles with larger size or weaker interactions, both the increasing and the declining amplitudes can be largely suppressed. The results provide a deep understanding of chain conformation in polymer nanocomposites.

关键词： Chain conformation Radius of gyration Polymer nanocomposites Density functional theory