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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
(η^-C_H_5)_2CeCl_5Mg_2(tmed)_2 was used as a catalyst to polymerize isoprene,Terminal ends of polyisoprene were identified as -CH_2-CH=CH_,which indicates that the insertion reaction of the monomer occurred between ...(η^-C_H_5)_2CeCl_5Mg_2(tmed)_2 was used as a catalyst to polymerize isoprene,Terminal ends of polyisoprene were identified as -CH_2-CH=CH_,which indicates that the insertion reaction of the monomer occurred between η^-allyl and cerium ion and gives a direct evidence for the η^-allyl mechanism of conjugated diene polymerzation with rare earth coordination catalysts.展开更多
In this paper, a dynamic epidemic control model on the uncorrelated complex networks is proposed. By means of theoretical analysis, we found that the new model has a similar epidemic threshold as that of the susceptib...In this paper, a dynamic epidemic control model on the uncorrelated complex networks is proposed. By means of theoretical analysis, we found that the new model has a similar epidemic threshold as that of the susceptible-infectedrecovered （SIR） model on the above networks, but it can reduce the prevalence of the infected individuals remarkably. This result may help us understand epidemic spreading phenomena on real networks and design appropriate strategies to control infections.展开更多
The title complexes were modeled using the semiempirical MOPAC and the newly developed SPARKLE paramerters of the lanthanides. The calculated bond dis tances and angles agreed well with those found from crystal struct...The title complexes were modeled using the semiempirical MOPAC and the newly developed SPARKLE paramerters of the lanthanides. The calculated bond dis tances and angles agreed well with those found from crystal structure measuremen ts. This technique allows us to screen a large number of molecules and get struc tural information within a very short time.展开更多
The complexity of large-scale network systems made of a large number of nonlinearly interconnected components is a restrictive facet for their modeling and analysis. In this paper, we propose a framework of hierarchic...The complexity of large-scale network systems made of a large number of nonlinearly interconnected components is a restrictive facet for their modeling and analysis. In this paper, we propose a framework of hierarchical modeling of a complex network system, based on a recursive unsupervised spectral clustering method. The hierarchical model serves the purpose of facilitating the management of complexity in the analysis of real-world critical infrastructures. We exemplify this by referring to the reliability analysis of the 380 kV Italian Power Transmission Network (IPTN). In this work of analysis, the classical component Importance Measures (IMs) of reliability theory have been extended to render them compatible and applicable to a complex distributed network system. By utilizing these extended IMs, the reliability properties of the IPTN system can be evaluated in the framework of the hierarchical system model, with the aim of providing risk managers with information on the risk/safety significance of system structures and components.展开更多
基金supported in part by the National Key R&D Program of China(No.2016YFB1200100)
文摘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.
文摘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.
文摘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.
基金Universiti Sains Malaysia -Science Fund Grant No.1001/PK1M1A/823003 and RU Grant No. 1001/PKIMIA/811196 for the financial support of this work
文摘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.
基金Partial funding for this project was produced a Grant-in-Aid for Scientifc Research (B) from Japan Society for the Promotion of Science (JSPS) to Tsunogae(Nos.20340148,22403017)a Grant-in-Aid for JSPS Fellows to Shimizu (No.23-311)
文摘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.
基金National Public Benefit Research Foundation of China (2008416048GYHY201006035)
文摘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.
基金supported by National Natural Science Foundation of China(No.51674279)China Postdoctoral Science Foundation(No.2016M602227)a grant from National Science and Technology Major Project(No.2017ZX05049-006)
文摘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.
文摘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.
文摘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.
基金Project(51805368)supported by the National Natural Science Foundation of ChinaProject(2018QNRC001)supported by the Young Elite Scientists Sponsorship Program,China+1 种基金Project(DMETKF2021017)supported by the Fund of State Key Laboratory of Digital Manufacturing Equipment and Technology,Huazhong University of Science and Technology,ChinaProject(HTL-0-21G07)supported by the National key Laboratory of Science and Technology on Heicopter Transmission,China。
文摘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.
基金funded by the National Key Research and Development Program of China(No.2017YFC1501204)the National Natural Science Foundation of China(Nos.51678536,41404096)+2 种基金the Scientific and Technological Research Program of Henan Province(No.171100310100)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(19HASTIT043)the Outstanding Young Talent Research Fund of Zhengzhou University(1621323001).
文摘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.
文摘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.
基金Sponsored by the National Natural Science Foundation of China(Grant No.50775050)the State Key Laboratory of Solidification Processing in NWPU(Grant No.200702)
文摘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.
基金Project supported by the National Natural Science Foundation of China.
文摘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.
文摘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.
文摘(η^-C_H_5)_2CeCl_5Mg_2(tmed)_2 was used as a catalyst to polymerize isoprene,Terminal ends of polyisoprene were identified as -CH_2-CH=CH_,which indicates that the insertion reaction of the monomer occurred between η^-allyl and cerium ion and gives a direct evidence for the η^-allyl mechanism of conjugated diene polymerzation with rare earth coordination catalysts.
基金Project supported by the National Natural Science Foundation of China (Grant No.60774088)the Program for New Century Excellent Talents of Higher Education of China (Grant No NCET 2005-290)the Special Research Fund for the Doctoral Program of Higher Education of China (Grant No 20050055013)
文摘In this paper, a dynamic epidemic control model on the uncorrelated complex networks is proposed. By means of theoretical analysis, we found that the new model has a similar epidemic threshold as that of the susceptible-infectedrecovered （SIR） model on the above networks, but it can reduce the prevalence of the infected individuals remarkably. This result may help us understand epidemic spreading phenomena on real networks and design appropriate strategies to control infections.
文摘The title complexes were modeled using the semiempirical MOPAC and the newly developed SPARKLE paramerters of the lanthanides. The calculated bond dis tances and angles agreed well with those found from crystal structure measuremen ts. This technique allows us to screen a large number of molecules and get struc tural information within a very short time.
文摘The complexity of large-scale network systems made of a large number of nonlinearly interconnected components is a restrictive facet for their modeling and analysis. In this paper, we propose a framework of hierarchical modeling of a complex network system, based on a recursive unsupervised spectral clustering method. The hierarchical model serves the purpose of facilitating the management of complexity in the analysis of real-world critical infrastructures. We exemplify this by referring to the reliability analysis of the 380 kV Italian Power Transmission Network (IPTN). In this work of analysis, the classical component Importance Measures (IMs) of reliability theory have been extended to render them compatible and applicable to a complex distributed network system. By utilizing these extended IMs, the reliability properties of the IPTN system can be evaluated in the framework of the hierarchical system model, with the aim of providing risk managers with information on the risk/safety significance of system structures and components.
