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基于JWST中红外观测数据的X-Complex小行星物理性质反演研究
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作者 矫恒越 徐小萌 +4 位作者 徐天弈 吴昀昭 金岩 张海波 刘志军 《空间控制技术与应用》 北大核心 2025年第5期16-25,共10页
X-complex小行星是一类在可见光-近红外波段无诊断性光谱特征、成分类型多样的重要天体,其中部分可能是已分异天体金属核心残余,是太阳系早期热演化研究及太空采矿的重要目标对象.由于Xcomplex小行星在可见光-近红外波段范围缺乏光谱吸... X-complex小行星是一类在可见光-近红外波段无诊断性光谱特征、成分类型多样的重要天体,其中部分可能是已分异天体金属核心残余,是太阳系早期热演化研究及太空采矿的重要目标对象.由于Xcomplex小行星在可见光-近红外波段范围缺乏光谱吸.收特征,热红外高光谱是研究X-complex小行星的重要手段.基于韦布空间望远镜中红外观测数据对7颗物理性质尚不明确的X-complex小行星进行了研究,利用近地小行星热模型及马尔科夫链蒙特卡洛方法反演了它们的发射率、直径、热集束参数以及几何反照率等物理信息.相较于以往观测,本文充分利用韦布空间望远镜的红外高光谱优势,通过连续谱段数据约束模型,提高了反演结果的可靠性.结果显示,这7颗小行星的直径范围为17.30~22.55 km,比喷气推进实验室数据库结果平均偏小41.5%,表明以往对小尺寸X-complex小行星直径存在普遍高估,进而反映其实际表面几何反照率普遍高于既有认知.反演的红外发射率光谱显示它们比硅酸盐小行星发射率低0.064~0.093,暗示它们表面可能被低发射率物质覆盖.所有小行星的中红外发射率光谱均展示了光谱特征,进一步印证了反演结果的可靠性. 展开更多
关键词 小行星 JWST 热物理模型 X-complex小行星 红外高光谱
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Ligand substitution of diiron hexacarbonyl complex with aminodiphosphine to prepare diiron aminophosphine complexes relevant to[FeFe]-hydrogenases
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作者 LIU Xufeng WANG Shaojie ZHAO Peihua 《无机化学学报》 北大核心 2025年第9期1851-1858,共8页
To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(... To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2. 展开更多
关键词 [FeFe]-hydrogenases diiron model complexes aminophosphine ligand STRUCTURE electrochemical performance
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Performance vs.Complexity Comparative Analysis of Multimodal Bilinear Pooling Fusion Approaches for Deep Learning-Based Visual Arabic-Question Answering Systems
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作者 Sarah M.Kamel Mai A.Fadel +1 位作者 Lamiaa Elrefaei Shimaa I.Hassan 《Computer Modeling in Engineering & Sciences》 2025年第4期373-411,共39页
Visual question answering(VQA)is a multimodal task,involving a deep understanding of the image scene and the question’s meaning and capturing the relevant correlations between both modalities to infer the appropriate... Visual question answering(VQA)is a multimodal task,involving a deep understanding of the image scene and the question’s meaning and capturing the relevant correlations between both modalities to infer the appropriate answer.In this paper,we propose a VQA system intended to answer yes/no questions about real-world images,in Arabic.To support a robust VQA system,we work in two directions:(1)Using deep neural networks to semantically represent the given image and question in a fine-grainedmanner,namely ResNet-152 and Gated Recurrent Units(GRU).(2)Studying the role of the utilizedmultimodal bilinear pooling fusion technique in the trade-o.between the model complexity and the overall model performance.Some fusion techniques could significantly increase the model complexity,which seriously limits their applicability for VQA models.So far,there is no evidence of how efficient these multimodal bilinear pooling fusion techniques are for VQA systems dedicated to yes/no questions.Hence,a comparative analysis is conducted between eight bilinear pooling fusion techniques,in terms of their ability to reduce themodel complexity and improve themodel performance in this case of VQA systems.Experiments indicate that these multimodal bilinear pooling fusion techniques have improved the VQA model’s performance,until reaching the best performance of 89.25%.Further,experiments have proven that the number of answers in the developed VQA system is a critical factor that a.ects the effectiveness of these multimodal bilinear pooling techniques in achieving their main objective of reducing the model complexity.The Multimodal Local Perception Bilinear Pooling(MLPB)technique has shown the best balance between the model complexity and its performance,for VQA systems designed to answer yes/no questions. 展开更多
关键词 Arabic-VQA deep learning-based VQA deep multimodal information fusion multimodal representation learning VQA of yes/no questions VQA model complexity VQA model performance performance-complexity trade-off
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A novel complex-high-order graph convolutional network paradigm:ChyGCN
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作者 郑和翔 苗书宇 顾长贵 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期665-672,共8页
In recent years,there has been a growing interest in graph convolutional networks(GCN).However,existing GCN and variants are predominantly based on simple graph or hypergraph structures,which restricts their ability t... In recent years,there has been a growing interest in graph convolutional networks(GCN).However,existing GCN and variants are predominantly based on simple graph or hypergraph structures,which restricts their ability to handle complex data correlations in practical applications.These limitations stem from the difficulty in establishing multiple hierarchies and acquiring adaptive weights for each of them.To address this issue,this paper introduces the latest concept of complex hypergraphs and constructs a versatile high-order multi-level data correlation model.This model is realized by establishing a three-tier structure of complexes-hypergraphs-vertices.Specifically,we start by establishing hyperedge clusters on a foundational network,utilizing a second-order hypergraph structure to depict potential correlations.For this second-order structure,truncation methods are used to assess and generate a three-layer composite structure.During the construction of the composite structure,an adaptive learning strategy is implemented to merge correlations across different levels.We evaluate this model on several popular datasets and compare it with recent state-of-the-art methods.The comprehensive assessment results demonstrate that the proposed model surpasses the existing methods,particularly in modeling implicit data correlations(the classification accuracy of nodes on five public datasets Cora,Citeseer,Pubmed,Github Web ML,and Facebook are 86.1±0.33,79.2±0.35,83.1±0.46,83.8±0.23,and 80.1±0.37,respectively).This indicates that our approach possesses advantages in handling datasets with implicit multi-level structures. 展开更多
关键词 raph convolutional network complex modeling complex hypergraph
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Multi-disciplinary design optimization with variable complexity modeling for a stratosphere airship 被引量:11
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作者 Shi YIN Ming ZHU Haoquan LIANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2019年第5期1244-1255,共12页
This paper proposes a hybrid architecture based on Multi-disciplinary Design Optimization(MDO) with the Variable Complexity Modeling(VCM) method, to solve the problem of general design optimization for a stratosphere ... This paper proposes a hybrid architecture based on Multi-disciplinary Design Optimization(MDO) with the Variable Complexity Modeling(VCM) method, to solve the problem of general design optimization for a stratosphere airship. Firstly, MDO based on the Concurrent SubSpace Optimization(CSSO) strategy is improved for handling the subsystem coupling problem in stratosphere airship design which contains aerodynamics, structure, and energy. Secondly, the VCM method based on the surrogate model is presented for reducing the computational complexity in high-fidelity modeling without loss of accuracy. Moreover, the global-to-local optimization strategy is added to the architecture to enhance the process. Finally, the result gives a prominent stratosphere airship general solution that validates the feasibility and efficiency of the optimization architecture. Besides, a sensitivity analysis is conducted to outline the critical impact upon stratosphere airship design. 展开更多
关键词 MULTI-DISCIPLINARY design optimization Sensitivity analysis STRATOSPHERE AIRSHIP Surrogate model VARIABLE complexITY modelING
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Optimal Parameter and Uncertainty Estimation of a Land Surface Model: Sensitivity to Parameter Ranges and Model Complexities 被引量:2
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作者 YoulongXIA Zong-LiangYANG +1 位作者 PaulL.STOFFA MrinalK.SEN 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2005年第1期142-157,共16页
Most previous land-surface model calibration studies have defined globalranges for their parameters to search for optimal parameter sets. Little work has been conducted tostudy the impacts of realistic versus global r... Most previous land-surface model calibration studies have defined globalranges for their parameters to search for optimal parameter sets. Little work has been conducted tostudy the impacts of realistic versus global ranges as well as model complexities on the calibrationand uncertainty estimates. The primary purpose of this paper is to investigate these impacts byemploying Bayesian Stochastic Inversion (BSI) to the Chameleon Surface Model (CHASM). The CHASM wasdesigned to explore the general aspects of land-surface energy balance representation within acommon modeling framework that can be run from a simple energy balance formulation to a complexmosaic type structure. The BSI is an uncertainty estimation technique based on Bayes theorem,importance sampling, and very fast simulated annealing. The model forcing data and surface flux datawere collected at seven sites representing a wide range of climate and vegetation conditions. Foreach site, four experiments were performed with simple and complex CHASM formulations as well asrealistic and global parameter ranges. Twenty eight experiments were conducted and 50 000 parametersets were used for each run. The results show that the use of global and realistic ranges givessimilar simulations for both modes for most sites, but the global ranges tend to produce someunreasonable optimal parameter values. Comparison of simple and complex modes shows that the simplemode has more parameters with unreasonable optimal values. Use of parameter ranges and modelcomplexities have significant impacts on frequency distribution of parameters, marginal posteriorprobability density functions, and estimates of uncertainty of simulated sensible and latent heatfluxes. Comparison between model complexity and parameter ranges shows that the former has moresignificant impacts on parameter and uncertainty estimations. 展开更多
关键词 optimal parameters uncertainty estimation CHASM model bayesian stochasticinversion parameter ranges model complexities
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Inclusion complexes of cefuroxime axetil with β-cyclodextrin:Physicochemical characterization, molecular modeling and effect of Larginine on complexation 被引量:3
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作者 Sarika Sapte Yogesh Pore 《Journal of Pharmaceutical Analysis》 SCIE CAS 2016年第5期300-306,共7页
The inclusion complexes of poorly water-soluble cephalosporin, cefuroxime axetil(CFA), were prepared with β-cyclodextrin(βCD) with or without addition of L-arginine(ARG) to improve its physicochemical properties. We... The inclusion complexes of poorly water-soluble cephalosporin, cefuroxime axetil(CFA), were prepared with β-cyclodextrin(βCD) with or without addition of L-arginine(ARG) to improve its physicochemical properties. We also investigated the effect of ARG on complexation efficiency(CE) of βCD towards CFA in an aqueous medium through phase solubility behaviour according to Higuchi and Connors. Although phase solubility studies showed AL(linear) type of solubility curve in presence and absence of ARG, the CE and association constant(Ks) of βCD towards CFA were significantly promoted in presence of ARG,justifying its use as a ternary component. The solid systems of CFA with βCD were obtained by spray drying technique with or without incorporation of ARG and characterized by differential scanning calorimetry(DSC), X-ray powder diffractometry(XRPD), scanning electron microscopy(SEM), and saturation solubility and dissolution studies. The molecular modeling studies provided a better insight into geometry and inclusion mode of CFA inside βCD cavity. The solubility and dissolution rate of CFA were significantly improved upon complexation with βCD as compared to CFA alone. However, ternary system incorporated with ARG performed better than binary system in physicochemical evaluation. In conclusion, ARG could be exploited as a ternary component to improve the physicochemical properties of CFA via βCD complexation. 展开更多
关键词 CEFUROXIME axetil Β-CYCLODEXTRIN INCLUSION complex MOLECULAR modeling PHYSICOCHEMICAL characterization
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Synthesis and molecular modeling study of Cu(Ⅱ) complexes derived from 2-(diphenylmethylene)hydrazinecarbothioamide derivatives with cholinesterase inhibitory activities 被引量:1
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作者 Yi Chen Chan Abdussalam Salhin Mohamed Ali +3 位作者 Melati Khairuddean Kooi Yeong Khaw Vikneswaran Murugaiyah Alireza Basiri 《Chinese Chemical Letters》 SCIE CAS CSCD 2013年第7期609-612,共4页
Thiosemicarbazones of 2-amino-5-chlorobenzophenone and 3-aminobenzophenone (L1-La) have been synthesized and their Cu(II) complexes (1-4) were afforded via coordination with cupric chloride. All these compounds ... Thiosemicarbazones of 2-amino-5-chlorobenzophenone and 3-aminobenzophenone (L1-La) have been synthesized and their Cu(II) complexes (1-4) were afforded via coordination with cupric chloride. All these compounds were characterized by UV-vis and lR spectroscopy together with CHN elemental analysis. NMR spectroscopy was also applied to characterize the ligands. In vitro cholinesterase inhibitory assays for the complexes (1-4) showed ICso values less than 10 ~molJL, with complex 1 exhibiting the most activity, ICso = 2.15 ~molJL and 2.16 i^molJL for AChE and BuChE, respectively. Molecular modeling simulation revealed the binding interaction template for complex I with the AChE and BuChE receptors. In DPPH assay, the complexes also showed more in vitro antioxidant activities in comt)arison tn their narent li^ands. 展开更多
关键词 Thiosemicarbazone Cu(II) complex Cholinesterase Molecular modeling
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Petrology and phase equilibrium modeling of sapphirine + quartz assemblage from the Napier Complex, East Antarctica: Diagnostic evidence for Neoarchean ultrahigh-temperature metamorphism 被引量:5
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作者 Hisako Shimizu Toshiaki Tsunogae M.Santosh 《Geoscience Frontiers》 SCIE CAS CSCD 2013年第6期655-666,共12页
A synthesis of the petrological characters of granulite facies rocks that contain equilibrium sapphirine + quartz assemblage from two localities (Tonagh Island (TI) and Priestley Peak (PP)) in the Napier Comple... A synthesis of the petrological characters of granulite facies rocks that contain equilibrium sapphirine + quartz assemblage from two localities (Tonagh Island (TI) and Priestley Peak (PP)) in the Napier Complex,East Antarctica,provides unequivocal evidence for extreme crustal metamorphism possibly associated with the collisional orogeny during Neoarchean.The reaction microstructures associated with sapphirine + quartz vary among the samples,probably suggesting different tectonic conditions during the metamorphic evolution.Sapphirine and quartz in TI sample were probably in equilibrium at the peak stage,but now separated by corona of Grt + Sil + Opx suggesting near isobaric cooling after the peak metamorphism,whereas the Spr + Qtz + Sil + Crd + Spl assemblage replaces garnet in PP sample suggesting post-peak decompression.The application of mineral equilibrium modeling in NCKFMASHTO system demonstrated that Spr + Qtz stability is lowered down to 930 ℃ due to small Fe3+ contents in the rocks (mole Fe2O3/(FeO + Fe2O3) =0.02).The TI sample yields a peak p-T range of 950-1100 ℃ and 7.5-11 kbar,followed by cooling toward a retrograde stage of 800-950 ℃ and 8-10 kbar,possibly along a counterclockwise p-T path.In contrast,the peak condition of the PP sample shows 1000-1050 ℃ and >12 kbar,which was followed by the formation ofSpr + Qtz corona around garnet at 930-970 ℃ and 6.7-7.7 kbar,suggesting decompression possibly along a clockwise p-T trajectory.Such contrasting p-T paths are consistent with a recent model on the structural framework of the Napier Complex that correlates the two areas to different crustal blocks.The different p-T paths obtained from the two localities might reflect the difference in the tectonic framework of these rocks within a complex Neoarchean subduction/collision belt. 展开更多
关键词 Ultrahigh-temperature granulite PETROLOGY Pseudosection modeling Napier complex ANTARCTICA
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VALIDATION OF NEAR-SURFACE WINDS OBTAINED BY A HYBRID WRF/CALMET MODELING SYSTEM OVER A COASTAL ISLAND WITH COMPLEX TERRAIN 被引量:9
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作者 路屹雄 汤剑平 +1 位作者 王元 宋丽莉 《Journal of Tropical Meteorology》 SCIE 2012年第3期284-296,共13页
The results from a hybrid approach that combines a mesoscale meteorological model with a diagnostic model to produce high-resolution wind fields in complex coastal topography are evaluated.The diagnostic wind model(Ca... The results from a hybrid approach that combines a mesoscale meteorological model with a diagnostic model to produce high-resolution wind fields in complex coastal topography are evaluated.The diagnostic wind model(California Meteorological Model,CALMET) with 100-m horizontal spacing was driven with outputs from the Weather Research and Forecasting(WRF) model to obtain near-surface winds for the 1-year period from 12 September 2003 to 11 September 2004.Results were compared with wind observations at four sites.Traditional statistical scores,including correlation coefficients,standard deviations(SDs) and mean absolute errors(MAEs),indicate that the wind estimates from the WRF/CALMET modeling system are produced reasonably well.The correlation coefficients are relatively large,ranging from 0.5 to 0.7 for the zonal wind component and from 0.75 to 0.85 for the meridional wind component.MAEs for wind speed range from 1.5 to 2.0 m s-1 at 10 meters above ground level(AGL) and from 2.0 to 2.5 m s-1 at 60 m AGL.MAEs for wind direction range from 30 to 40 degrees at both levels.A spectral decomposition of the time series of wind speed shows positive impacts of CALMET in improving the mesoscale winds.Moreover,combining the CALMET model with WRF significantly improves the spatial variability of the simulated wind fields.It can be concluded that the WRF/CALMET modeling system is capable of providing a detailed near-surface wind field,but the physics in the diagnostic CALMET model needs to be further improved. 展开更多
关键词 near-surface winds WRF/CALMET modeling system complex terrain
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A multi-mechanism numerical simulation model for CO_(2)-EOR and storage in fractured shale oil reservoirs 被引量:2
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作者 Yuan-Zheng Wang Ren-Yi Cao +3 位作者 Zhi-Hao Jia Bin-Yu Wang Ming Ma Lin-Song Cheng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1814-1828,共15页
Under the policy background and advocacy of carbon capture,utilization,and storage(CCUS),CO_(2)-EOR has become a promising direction in the shale oil reservoir industry.The multi-scale pore structure distribution and ... Under the policy background and advocacy of carbon capture,utilization,and storage(CCUS),CO_(2)-EOR has become a promising direction in the shale oil reservoir industry.The multi-scale pore structure distribution and fracture structure lead to complex multiphase flow,comprehensively considering multiple mechanisms is crucial for development and CO_(2) storage in fractured shale reservoirs.In this paper,a multi-mechanism coupled model is developed by MATLAB.Compared to the traditional Eclipse300 and MATLAB Reservoir Simulation Toolbox(MRST),this model considers the impact of pore structure on fluid phase behavior by the modified Peng—Robinson equation of state(PR-EOS),and the effect simultaneously radiate to Maxwell—Stefan(M—S)diffusion,stress sensitivity,the nano-confinement(NC)effect.Moreover,a modified embedded discrete fracture model(EDFM)is used to model the complex fractures,which optimizes connection types and half-transmissibility calculation approaches between non-neighboring connections(NNCs).The full implicit equation adopts the finite volume method(FVM)and Newton—Raphson iteration for discretization and solution.The model verification with the Eclipse300 and MRST is satisfactory.The results show that the interaction between the mechanisms significantly affects the production performance and storage characteristics.The effect of molecular diffusion may be overestimated in oil-dominated(liquid-dominated)shale reservoirs.The well spacing and injection gas rate are the most crucial factors affecting the production by sensitivity analysis.Moreover,the potential gas invasion risk is mentioned.This model provides a reliable theoretical basis for CO_(2)-EOR and sequestration in shale oil reservoirs. 展开更多
关键词 CO_(2)-EOR CO_(2)storage Shale oil reservoir complex fracture model Multiple mechanisms
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The Fuzzy Modeling Algorithm for Complex Systems Based on Stochastic Neural Network
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作者 李波 张世英 李银惠 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2002年第3期46-51,共6页
A fuzzy modeling method for complex systems is studied. The notation of general stochastic neural network (GSNN) is presented and a new modeling method is given based on the combination of the modified Takagi and Suge... A fuzzy modeling method for complex systems is studied. The notation of general stochastic neural network (GSNN) is presented and a new modeling method is given based on the combination of the modified Takagi and Sugeno's (MTS) fuzzy model and one-order GSNN. Using expectation-maximization(EM) algorithm, parameter estimation and model selection procedures are given. It avoids the shortcomings brought by other methods such as BP algorithm, when the number of parameters is large, BP algorithm is still difficult to apply directly without fine tuning and subjective tinkering. Finally, the simulated example demonstrates the effectiveness. 展开更多
关键词 complex system modeling General stochastic neural network MTS fuzzy model Expectation-maximization algorithm
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Landscape Design of Commercial Housing Based on the Comprehensive Development Model of City Complex——A Case Study on Landscape Design of Chenglong-International 被引量:1
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作者 YANG Maomao CHEN Youzhu ZHANG Xu 《Journal of Landscape Research》 2013年第Z1期7-12,共6页
With the acceleration of urbanization, city complex as an intensive urban organization form has gradually grown up in China. By consulting relevant documents of city complex, emergence background and related concepts ... With the acceleration of urbanization, city complex as an intensive urban organization form has gradually grown up in China. By consulting relevant documents of city complex, emergence background and related concepts of city complex were introduced, landscape design of Chenglong-International was analyzed to propose landscape design principles and concepts of city complex under the compound development model, landscape processing techniques of outdoor functional subareas and transitional areas were introduced to provide useful reference for the landscape design of city complex. 展开更多
关键词 CITY complex COMPREHENSIVE development model LANDSCAPE architecture LANDSCAPE design
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Complex geometric modeling and tooth contact analysis of a helical face gear pair with arc-tooth
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作者 MO Shuai SONG Wen-hao +3 位作者 ZHU Sheng-ping FENG Zhi-you TANG Wen-jie GAO Han-jun 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第4期1213-1225,共13页
A complex geometric modeling method of a helical face gear pair with arc-tooth generated by an arc-profile cutting(APC)disc is proposed,and its tooth contact characteristics are analyzed.Firstly,the spatial coordinate... A complex geometric modeling method of a helical face gear pair with arc-tooth generated by an arc-profile cutting(APC)disc is proposed,and its tooth contact characteristics are analyzed.Firstly,the spatial coordinate system of an APC face gear pair is established based on meshing theory.Combining the coordinate transformation matrix and the tooth profile of the cutter,the equations of the curve envelope of the APC face gear pair are obtained.Then the surface equations are solved to extract the point clouds data by programming in MATLAB,which contains the work surface and the fillet surface of the APC face gear pair.And the complex geometric model of the APC face gear pair is built by fitting its point clouds.At last,through the analysis of the tooth surface contact,the sensitivity of the APC face gear to the different types of mounting errors is obtained.The results show that the APC face gear pair is the most sensitive to mounting errors in the tooth thickness direction,and it should be strictly controlled in the actual application. 展开更多
关键词 arc-tooth face gear complex geometric modeling point clouds mounting errors tooth contact analysis
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GPR Wave Propagation Model in a Complex Geoelectric Structure Using Conformal First-Order Symplectic Euler Algorithm
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作者 Man Yang Hongyuan Fang +3 位作者 Juan Zhang Fuming Wang Jianwei Lei Heyang Jia 《Computers, Materials & Continua》 SCIE EI 2019年第8期793-816,共24页
Possessing advantages such as high computing efficiency and ease of programming,the Symplectic Euler algorithm can be applied to construct a groundpenetrating radar(GPR)wave propagation numerical model for complex geo... Possessing advantages such as high computing efficiency and ease of programming,the Symplectic Euler algorithm can be applied to construct a groundpenetrating radar(GPR)wave propagation numerical model for complex geoelectric structures.However,the Symplectic Euler algorithm is still a difference algorithm,and for a complicated boundary,ladder grids are needed to perform an approximation process,which results in a certain amount of error.Further,grids that are too dense will seriously decrease computing efficiency.This paper proposes a conformal Symplectic Euler algorithm based on the conformal grid technique,amends the electric/magnetic fieldupdating equations of the Symplectic Euler algorithm by introducing the effective dielectric constant and effective permeability coefficient,and reduces the computing error caused by the ladder approximation of rectangular grids.Moreover,three surface boundary models(the underground circular void model,the undulating stratum model,and actual measurement model)are introduced.By comparing reflection waveforms simulated by the traditional Symplectic Euler algorithm,the conformal Symplectic Euler algorithm and the conformal finite difference time domain(CFDTD),the conformal Symplectic Euler algorithm achieves almost the same level of accuracy as the CFDTD method,but the conformal Symplectic Euler algorithm improves the computational efficiency compared with the CFDTD method dramatically.When the dielectric constants of the two materials vary greatly,the conformal Symplectic Euler algorithm can reduce the pseudo-waves almost by 80% compared with the traditional Symplectic Euler algorithm on average. 展开更多
关键词 Symplectic Euler algorithm conformal grid complex geoelectric model ground-penetrating radar pseudo-reflection wave
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Performance-based fractal fracture model for complex fracture network simulation 被引量:1
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作者 Wen-Dong Wang Yu-Liang Su +2 位作者 Qi Zhang Gang Xiang Shi-Ming Cui 《Petroleum Science》 SCIE CAS CSCD 2018年第1期126-134,共9页
The paper presents a novel hydraulic fracturing model for the characterization and simulation of the complex fracture network in shale gas reservoirs. We go beyond the existing method that uses planar or orthogonal co... The paper presents a novel hydraulic fracturing model for the characterization and simulation of the complex fracture network in shale gas reservoirs. We go beyond the existing method that uses planar or orthogonal conjugate fractures for representing the ''complexity'' of the network. Bifurcation of fractures is performed utilizing the Lindenmayer system based on fractal geometry to describe the fracture propagation pattern, density and network connectivity. Four controlling parameters are proposed to describe the details of complex fractures and stimulated reservoir volume(SRV). The results show that due to the multilevel feature of fractal fractures, the model could provide a simple method for contributing reservoir volume calibration. The primary-and second-stage fracture networks across the overall SRV are the main contributions to the production, while the induced fracture network just contributes another 20% in the late producing period. We also conduct simulation with respect to different refracturing cases and find that increasing the complexity of the fracture network provides better performance than only enhancing the fracture conductivity. 展开更多
关键词 Fractal geometry Fractal fracture model complex fracture network characterization Contributing reservoirvolume REFRACTURING
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An Incremental Model Transfer Method for Complex Process Fault Diagnosis 被引量:5
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作者 Xiaogang Wang Xiyu Liu Yu Li 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第5期1268-1280,共13页
Fault diagnosis is an important measure to ensure the safety of production, and all kinds of fault diagnosis methods are of importance in actual production process. However, the complexity and uncertainty of productio... Fault diagnosis is an important measure to ensure the safety of production, and all kinds of fault diagnosis methods are of importance in actual production process. However, the complexity and uncertainty of production process often lead to the changes of data distribution and the emergence of new fault classes, and the number of the new fault classes is unpredictable. The reconstruction of the fault diagnosis model and the identification of new fault classes have become core issues under the circumstances. This paper presents a fault diagnosis method based on model transfer learning and the main contributions of the paper are as follows: 1) An incremental model transfer fault diagnosis method is proposed to reconstruct the new process diagnosis model. 2) Breaking the limit of existing method that the new process can only have one more class of faults than the old process, this method can identify M faults more in the new process with the thought of incremental learning. 3) The method offers a solution to a series of problems caused by the increase of fault classes. Experiments based on Tennessee-Eastman process and ore grinding classification process demonstrate the effectiveness and the feasibility of the method. 展开更多
关键词 complex process FAULT DIAGNOSIS INCREMENTAL LEARNING model TRANSFER
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Evaluaton model for the geometry complexity of casting based on fuzzy theory 被引量:1
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作者 吴士平 徐琴 +1 位作者 薛祥 吴光然 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2012年第4期9-12,共4页
The parameters that describe the complex degree of a certain casting are of some uncertainty. Therefore, a new method based on the fuzzy theory to classify the complex degree of castings has been presented in this pap... The parameters that describe the complex degree of a certain casting are of some uncertainty. Therefore, a new method based on the fuzzy theory to classify the complex degree of castings has been presented in this paper. The feasibility of fuzzy theory in describing the complex degree of castings has been discussed and the procedure of this method has been specified by analyzing the complex degrees of some typical castings. The element factors that influence the casting complexity, have been summarized, which include the wall-thickness and the number of transition surface, etc. The results show that it is reasonable and practicable to classify the complex degree of castings with the fuzzy theory. 展开更多
关键词 fuzzy theory CASTING complex degree GEOMETRY evaluation model
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MM CALCULATIONS OF THE METAL-PROTEIN MODEL COMPLEXES Ⅰ.MOLECULAR FORCE FIELD FOR COBALT COMPEXES
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作者 Wei Liang CAO Hong You GUO +2 位作者 Shi Lei XUE Xin Gang Ren Zuo Xing WangBeijing Institute of Chemical Technology,Beijing 100029 《Chinese Chemical Letters》 SCIE CAS CSCD 1992年第5期393-396,共4页
Cobalt-protein complexes play an important role in biochemical processes.The structure of the model molecule,Co(H_2O)_3SO_4(phen) has been studied by molecular mechanics.The molecular force field (MM2) parameters have... Cobalt-protein complexes play an important role in biochemical processes.The structure of the model molecule,Co(H_2O)_3SO_4(phen) has been studied by molecular mechanics.The molecular force field (MM2) parameters have been developed for the particular class of the complexes. 展开更多
关键词 CO MM CALCULATIONS OF THE METAL-PROTEIN model complexES MOLECULAR FORCE FIELD FOR COBALT COMPEXES 耳卜
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Tsallis holographic dark energy under complex form of quintessence model
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作者 J Sadeghi S Noori Gashti T Azizi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2023年第2期157-167,共11页
In this paper,we use a Tsallis holographic dark energy model in two forms,interacting and noninteracting cases,to acquire some parameters as the equation of state for the energy density of the Tsallis model in the FRW... In this paper,we use a Tsallis holographic dark energy model in two forms,interacting and noninteracting cases,to acquire some parameters as the equation of state for the energy density of the Tsallis model in the FRW Universe concerning the complex form of quintessence model.We will study the cosmology of complex quintessence by revamping the potential and investigating the scalar field dynamics.Then we analyze(w-w’)and stability in two cases,i.e.noninteracting and interacting.We will explore whether these cases describe a real Universe by calculating fractional energy densityΩ_(D)and concerning two parts of the quintessence field effect(complex and real part)by considering the real part of this field to be a slow-roll field.We know that the part in which the fractional energy density(Ω_(D)>1)does not describe a real Universe.Also,we specified an interacting coupling parameter b2that depends on the constant parameter of the Tsallis holographic model(δ)with respect to fractional energy density(0.73).Unlike independence between the fractional energy density and interacting coupling in the real quintessence model,we determine a relationship among these parameters in this theory.Finally,by plotting some figures,we specify the features of(w-w’)and(ν^(2)_(s))in two cases and compare the result with each other. 展开更多
关键词 Tsallis holographic model complex form of quintessence model STABILITY
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